Rishiraj Institute of Technology, Indore
Transcript of Rishiraj Institute of Technology, Indore
RISHIRAJ INSTITUTE OF TECHNOLOGY, INDOREREVTI GRAM, SAWER ROAD, INDORE-453331
MINNOR PROJECT ON
E-WASTE RECYCLING IN INDIA
SESSION 2009-2010
MECHANICAL ENGINEERING2006-2010
RAJIV GANDHI PROUDYOGIKI VISHWAVIDYALAYA, BHOPAL
GUIDED BY SUBMITTED BYH.O.D. S. B. DIGHE NITIN SINGHLECTURER R. MEHTA
1 E-waste recycling in India
CONTENT
1.0. ABSTRAC
2.0. INTRODUCTION
3.0. DEFINITION
4.0. DESTINATION OF E-WASTE
5.0. INDIAN SCENARIO
6.0. THE STATUS
7.0. BASEL CONVENTION
8.0. E-TOXICS IN E-WASTE
8.1. E-WASTE AND ITS EFFECT ON HEALTH AND THE ENVIRONMENT
9.0. LIFE CYCLE OF E-WASTE
10.0. MANAGEMENT OF E-WASTES
10.1. INVENTORY MANAGEMENT
10.2. PRODUCTION-PROCESS MODIFICATION
10.3. VOLUME REDUCTION
10.4. RECOVERY AND REUSE
10.5. SUSTAINABLE PRODUCT DESIGN
11.0. WASTE MANAGEMENT CONCEPTS
11.1. RESOURCE RECOVERY
11.2. RECYCLING
11.3. WASTE MANAGEMENT TECHNIQUES
11.3.1. LANDFILL
11.3.2. INCINERATION
11.3.3. COMPOSTING AND ANAEROBIC DIGESTION
11.3.4. MECHANICAL BIOLOGICAL TREATMENT
11.3.5. PYROLYSIS & GASIFICATION
12.0. RECYCLING OF E-WASTE
12.1. RECYCLING/RECOVERY SYSTEM
12.2. BIFURCATION OF ELECTRONIC SCRAP
12.2.1. PRINTED CIRCUIT BOARDS (PCBS)
12.2.2. CHARACTERISTICS OF PCB SCRAP
12.2.3. DENSITY DIFFERENCES
12.2.4. MAGNETIC AND ELECTRICAL CONDUCTIVITY DIFFERENCES
12.2.5. POLYFORMITY
12.2.6. LIBERATION SIZE
2 E-waste recycling in India
12.2.7. CHEMICAL REACTIVITY
12.2.8. ELECTROPOSITIVITY
12.3. DISASSEMBLY
12.4. MECHANICAL/PHYSICAL RECYCLING PROCESS
12.5. MECHANICAL APPROACHES OF RECYCLING ELECTRONIC SCRAP
12.6. HYDROMETALLURGICAL APPROACHES
12.7. EXTRACTION OF IC/ OTHER COMPONENTS FROM PCB
12.7.1. RECOVERY OF GOLD
12.7.2. MONITORS
12.7.2.1. Recovery of Glass from CRT
12.7.2.2. Yoke Core, Metallic Core and Copper from Transformers
12.7.2.3. Copper Extraction from Wires
12.7.2.4. Manual drawing of Wires for Copper
12.7.2.5. Plastic Shredding and Graining
12.7.2.6. Dismantling of compressor & segregation of compressor & cooling box
12.8. DISPOSAL
12.9. ADVANTAGES OF RECYCLING E-WASTE
13.0. RESPONSIBILITIES OF GOVERNMENT, INDUSTRIES, AND CITIZEN
13.1. RESPONSIBILITIES OF THE GOVERNMENT
13.2. RESPONSIBILITY AND ROLE OF INDUSTRIES
13.3. RESPONSIBILITIES OF THE CITIZEN
14.0. E-WASTE POLICY FOR INDIA
15.0. CONCLUSION
16.0. REFERENCES
3 E-waste recycling in India
1. ABSTRACT
The production of electric and electronic equipment (EEE) is one of the fastest growing areas.This
development has resulted in an increase of waste electric and electronic equipment (WEEE).In view
of the environmental problems involved in the management of WEEE, many counties and
organizations have drafted national legislation to improve the reuse, recycling and other forms of
recovery of such wastes so as to reduce disposal. Recycling of WEEE is an important subject not
only from the point of waste treatment but also from the recovery of valuable materials.
"E-waste" is a popular, informal name for electronic products nearing the end of their "useful life.
"E-wastes are considered dangerous, as certain components of some electronic products contain
materials that are hazardous, depending on their condition and density. The hazardous content of
these materials pose a threat to human health and environment. Discarded computers, televisions,
VCRs, stereos, copiers, fax machines, electric lamps, cell phones, audio equipment and batteries if
improperly disposed can leach lead and other substances into soil and groundwater. Many of these
products can be reused, refurbished, or recycled in an environmentally sound manner so that they are
less harmful to the ecosystem. This paper highlights the hazards of e-wastes, the need for its
appropriate management and options that can be implemented.
4 E-waste recycling in India
2. INTRODUCTION
Industrial revolution followed by the advances in information technology during the last century has
radically changed people's lifestyle. Although this development has helped the human race,
mismanagement has led to new problems of contamination and pollution. The technical prowess
acquired during the last century has posed a new challenge in the management of wastes. For
example, personal computers (PCs) contain certain components, which are highly toxic, such as
chlorinated and brominated substances, toxic gases, toxic metals, biologically active materials, acids,
plastics and plastic additives. The hazardous content of these materials pose an environmental and
health threat. Thus proper management is necessary while disposing or recycling ewastes.
These days computer has become most common and widely used gadget in all kinds of activities
ranging from schools, residences, offices to manufacturing industries. E-toxic components in
computers could be summarized as circuit boards containing heavy metals like lead & cadmium;
batteries containing cadmium; cathode ray tubes with lead oxide & barium; brominates flame
retardants used on printed circuit boards, cables and plastic casing; poly vinyl chloride (PVC) coated
copper cables and plastic computer casings that release highly toxic dioxins & furans when burnt to
recover valuable metals; mercury switches; mercury in flat screens; poly chlorinated biphenyl's
(PCB's) present in older capacitors; transformers; etc. Basel Action Network (BAN) estimates that
the 500 million computers in the world contain 2.87 billion kg of plastics, 716.7 million kg of lead
and 286,700 kg of mercury. The average 14-inch monitor uses a tube that contains an estimated 2.5
to 4 kg of lead. The lead can seep into the ground water from landfills thereby contaminating it. If
the tube is crushed and burned, it emits toxic fumes into the air.
Long-term exposure to deadly component chemicals and metals like lead, cadmium, chromium,
mercury and polyvinyl chlorides (PVC) can severely damage the nervous systems, kidneys and
bones, and the reproductive and endocrine systems, and some of them are carcinogenic and
neurotoxin. It is a generic term used to describe old, end-of-life electronic appliances such as
computers, laptops, TVs, DVD players, Mobile Phones, MP-3 players, etc., which have been
disposed of by their original users. Though there is no generally accepted definition of E-waste, in
most cases, E-waste comprises of relatively expensive and essentially durable products used for data
processing, tile-communications or entertainment in private house-holds and businesses.
5 E-waste recycling in India
Public perception of E-waste is often restricted to a narrower sense, comprising mainly of end-of life
information and tile-communication equipment, and consumer electronics. However, technically
speaking, electronic waste is only a sub-set of WEEE (Waste Electrical & Electronic
Equipment). According to the Organization for Economic Cooperation & Development
(OECD), any appliance using an electric power supply that has reached its end-of-life would come
under WEEE. At macro-level, there are two ways to handle the E-Wastes: Disposal or Recycle /
Refurbish.
6 E-waste recycling in India
3. DEFINITION
Electronic waste includes computers, entertainment electronics, mobile phones and Other items that
have been discarded by their original users. While there is no Generally accepted definition of
electronic waste, in most cases electronic waste Consists of electronic products that were used for
data processing, Telecommunications or entertainment in private households and businesses that are
now considered obsolete, broken, or un-repairable. Despite its common classification
as a waste, disposed electronics are a considerable category of secondary resource due to their
significant suitability for direct reuse, refurbishing, and material recycling of its constituent raw
materials. Re-conceptualization of electronic waste as a resource thus preempts its potentially
hazardous qualities.
Definition of electronic waste according to the WEEE directive :
· Large household appliances (ovens, refrigerators etc.)
· Small household appliances (toasters, vacuum cleaners etc.)
· Office & communication (PCs, printers, phones, faxes etc.)
· Entertainment electronics (TVs, HiFis, portable CD players etc.)
· Lighting equipment (mainly fluorescent tubes)
· E-tools (drilling machines, electric lawnmowers etc.)
· Sports & leisure equipment (electronic toys, training machines etc.)
· Medical appliances and instruments
· Surveillance equipment
· Automatic issuing systems (ticket issuing machines etc.)
7 E-waste recycling in India
4. DESTINATION OF E-WASTE:
The waste is imported by over 35 countries, which include India, China, Pakistan, and Malaysia etc.
Fig. 1 shows the global E-waste traffic routes across Asia. The waste generated by the consumers of
electronic goods gets collected by scavengers or garbage collectors, and usually gets deported to
backyard stripping houses etc, where the potentially valuable substances are separated from the
waste and the residue, which may still contain many hazardous (or useful) substances, is dumped or
incinerated.
Fig-1 Asian E-Waste Traffic
8 E-waste recycling in India
5. INDIAN SCENARIO
There is an estimate that the total obsolete computers originating from government offices, business
houses, industries and household is of the order of 2 million nos. Manufactures and assemblers in a
single calendar year, estimated to produce around 1200 tons of electronic scrap. It should be noted
that obsolesce rate of personal computers (PC) is one in every two years. The consumers find it
convenient to buy a new computer rather than upgrade the old one due to the changing
configuration, technology and the attractive offers of the manufacturers. Due to the lack of
governmental legislations on e-waste, standards for disposal, proper mechanism for handling these
toxic hi-tech products, mostly end up in landfills or partly recycled in a unhygienic conditions and
partly thrown into waste streams. Computer waste is generated from the individual households; the
government, public and private sectors; computer retailers; manufacturers; foreign embassies;
secondary markets of old PCs. Of these, the biggest sources of PC scrap are foreign countries that
export huge computer waste in the form of reusable components.
Electronic waste or e-waste is one of the rapidly growing environmental problems of the world. In
India, the electronic waste management assumes greater significance not only due to the generation
of our own waste but also dumping of e-waste particularly computer waste from the developed
countries.
With extensively using computers and electronic equipments and people dumping old electronic
goods for new ones, the amount of E-Waste generated has been steadily increasing. At present
Bangalore alone generates about 8000 tonnes of computer waste annually and in the absence of
proper disposal, they find their way to scrap dealers.
E-Parisaraa, an eco-friendly recycling unit on the outskirts of Bangalore which is located in
Dobaspet industrial area, about 45 Km north of Bangalore, makes full use of E-Waste. The plant
which is India’s first scientific e-waste recycling unit will reduce pollution, landfill waste and
recover valuable metals, plastics & glass from waste in an eco-friendly manner. E-Parisaraa has
developed a circuit to extend the life of tube lights. The circuit helps to extend the life of fluorescent
tubes by more than 2000 hours. If the circuits are used, tube lights can work on lower voltages. The
initiative is to aim at reducing the accumulation of used and discarded electronic and electrical
9 E-waste recycling in India
equipments.
India as a developing country needs simpler, low cost technology keeping in view of maximum
resource recovery in an environmental friendly methodologies. E-Parisaraa, deals with practical
aspect ofe-waste processing as mentioned below by hand. Phosphor affects the display resolution
and luminance of the images that is seen in the monitor.
E-Parisaraa’s Director Mr. P. Parthasarathy, an IIT Madras graduate, and a former consultant for a
similar e-waste recycling unit in Singapore, has developed an eco-friendly methodology for reusing,
recycling and recovery of metals, glass & plastics with non-incineration methods . The hazardous
materials are segregated separately and send for secure land fill for ex.: phosphor coating, LED’s,
mercury etc.
We have the technology to recycle most of the e-waste and only less than one per cent of this will be
regarded as waste, which can go into secure landfill planned in the vicinity by the HAWA project.
10 E-waste recycling in India
6. THE STATUS
The first comprehensive study to estimate the annual generation of E-waste in India and answer the
questions above is being under taken up by the National WEEE Taskforce. The preliminary
estimates suggest that total WEEE generation in India is approximately 1,46,000 tonne per year.
The top states in order of highest contribution to WEEE are:-
1.Maharashtra, 2.Andhra Pradesh, 3.Tamil Nadu, 4. Uttar Pradesh,
5.West Bengal, 6.Delhi, Karnataka, 7.Gujarat, 8.Madhya Pradesh, and
9.Punjab.
The city-wise ranking of largest WEEE generators are:-
1.Mumbai, 2.Delhi, 3.Bangalore, 4.Chennai, 5.Kolkatta, 6.Ahmedabad,
7.Hyderabad, 8.Pune, 9.Surat, and 10.Nagpur.
An estimated 30,000 computers become obsolete every year from the IT industry in Bangalore
alone simply due to an extremely high obsolescence rate of 30 per cent per annum.
Almost 50 per cent of the PCs sold in India are products from the secondary market and are re-
assembled on old components. The remaining market share is cover by multinational-manufacturers
(30 per cent), and Indian brands (20 per cent). Three categories of WEEE account for almost 90 per
cent of the generation - Large Household Appliances (42 per cent), Information & Communications
Technology Equipment (34 per cent), Consumer Electronics (14 per cent).
The E-waste recycled by the formal recyclers is done under environmentally sound practices which
ensure that damage is minimized to the environment. They also adopt processes so that the
workforce is not exposing to toxic and hazardous substances released during recycling process. But
they cannot match either the reach or the network of the informal recyclers used for sourcing of old
electrical and electronic items from business as well as individual households.
11 E-waste recycling in India
The items are collect, segregated and the informal recyclers further dismantle the ones that cannot be
sold as it is. The final step is recycling which is mainly manual using simple tools like hammer,
screw driver, etc., and by the use of rudimentary techniques like burning of wires in the
open, using acid bath for extraction of precious metals.
Furthermore, these activities are carried out without wearing any protective gear like masks, gloves,
etc. In the absence of suitable processes and protective measures, recycling E-waste results in toxic
emission to the air, water, soil and poses serious environmental and health hazards. Thus, the
challenges are manifold: environmental and health hazards; lack of awareness amongst various
stakeholders including public at large; investment required for setting up of state-of-the-art waste
management facilities; monitoring and reporting of the E-waste generated; and most importantly,
reconciling technological advancement with sustainable development.
E-WASTE SITUATION IN INDIA
At present, the e-waste management system in India is characterised by a market driven collection
and recycling implying no direct cost to consumers, producers or taxpayers. The system is
dominated by the informal sector in backyard workshops . Backyard workshops are considered being
a part of the informal economy. Informal and underground economy is defined by Frey and
Schneider (2000): “It comprises all presently not recorded productive (i.e. value-adding) activities
which should be in the national product (GNP).” In this thesis the informal scrap industry is seen as
recycling facilities that do not comply with state regulations regarding taxation, environmental
protection or safety standards (Streicher-Porte, 2006). Up to now no regulations or controls on
material or financial flows, standards of emissions or occupational hazards have been implemented
(Sinha, 2004). Though India signed the Basel Convention, there is no specific legislation regulating
the export or the collection and treatment of E-waste. There are however several existing
environmental legislations which are of importance and useful in the context of E-waste. India is one
of the countries that have to deal with the arising load of E-waste. Figure 2 indicates that the PC
growth per capita in India had been over 1’000 % between 1993 and 2000. From 2002 to 2004 the
sales of computers in India almost doubled as a market study shows, which had been performed in
22 Indian cities (see Figure 2).
12 E-waste recycling in India
Fig 2. Top scoring countries in PC growth rates (left) and penetration rates (right) (Schwarzeret al., 2005).
Since the growth of PC sales correlates with the generation of E-waste (Jain and Sareen, 2006) these
sales implicate a massive increase of E-waste. As an outcome of Phase I of seco’s global E-waste
programme the Indo-German-Swiss Initiative for E-waste management had been set up. It brings
together the experience and expertise of all the partners (MoEF, GTZ, seco) involved. The partners
work in close collaboration with manufacturers, users, recyclers, and NGOs to develop a sustainable
e-waste management system in India (e-Waste Guide India, 2006).
13 E-waste recycling in India
Fig 3. PC market trends in India from 1997 to 2004 (BIRD, 2005).
14 E-waste recycling in India
7. BASEL CONVENTION
The fundamental aims of the fundamental aims of the Basel Convention are the control and
reduction of trans-boundary movements of hazardous and other wastes including the prevention and
minimization of their generation, the environmentally sound management of such wastes and the
active promotion of the transfer and use of technologies.
A Draft Strategic Plan has been proposed for the implementation of the Basel Convention. The Draft
Strategic Plan takes into account existing regional plans, program or strategies, the decisions of the
Conference of the Parties and its subsidiary bodies, ongoing project activities and process of
international environmental governance and sustainable development. The Draft requires action at
all levels of society: training, information, communication, methodological tools, capacity building
with financial support, transfer of know-how, knowledge and sound, proven cleaner technologies
and processes to assist in the concrete implementation of the Basel Declaration. It also calls for the
effective involvement and coordination by all concerned stakeholders as essential for achieving the
aims of the Basel Declaration within the approach of common but differentiated responsibility.
Are the control and reduction of trans-boundary movements of hazardous and other wastes including
the prevention and minimization of their generation, the environmentally sound management of such
wastes and the active promotion of the transfer and use of technologies?
A set. of interrelated and mutually supportive strategies are proposed to support the concrete
implementation of the activities as indicated is described below:
1. To involve experts in designing communication tools for creating awareness at the highest
level to promote the aims of the Basel Declaration on environmentally sound management
and the ratification and implementation of the Basel Convention, its amendments and
protocol with the emphasis on the short-term activities.
2. To engage and stimulate a group of interested parties to assist the secretariat in exploring
fund raising strategies including the preparation of projects and in making full use of
expertise in non-governmental organizations and other institutions in joint projects.
3. To motivate selective partners among various stakeholders to bring added value to making
progress in the short-term.
15 E-waste recycling in India
4. To disseminate and make information easily accessible through the internet and other
electronic and printed materials on the transfer of know-how, in particular through Basel
Convention Regional Centers (BCRCs).
5. To undertake periodic review of activities in relation to the agreed indicators;
6. To collaborate with existing institutions and program to promote better use of cleaner
technology and its transfer, methodology, economic instruments or policy to facilitate or
support capacity-building for the environmentally sound management of hazardous and other
wastes.
The Basel Convention brought about a respite to the trans-boundary movement of hazardous waste.
India and other countries have ratified the convention. However United States (US) is not a party to
the ban and is responsible for disposing hazardous waste, such as, e-waste to Asian countries even
today. Developed countries such as US should enforce stricter legislations in their own country for
the prevention of this horrifying act.
In the European Union where the annual quantity of electronic waste is likely to double in the next
12 years, the European Parliament recently passed legislation that will require manufacturers to take
back their electronic products when consumers discard them. This is called Extended Producer
Responsibility. It also mandates a timetable for phasing out most toxic substances in electronic
products.
16 E-waste recycling in India
8. E-TOXICS IN E-WASTE
"Printed Circuit Boards contain heavy metals such as Antimony, Silver, Chromium, Zinc, Lead, Tin
and Copper. According to some estimates there is hardly any other product for which the sum of the
environmental impacts of raw material, extraction, industrial, refining and production, use and
disposal is as extensive as for printed circuit boards."
"In short, the product developers of electronic products are introducing chemicals on a scale which is
totally incompatible with the scant knowledge of their environmental or biological characteristics."
TABLE-1 Material used in a desktop computer and the efficiency of current
recycling processes
Name content (% of
total weight)
Recycling
Efficiency %
Weight of
material (lb)
Use/Location
Plastics 22.9907 13.8 20 Includes organics, oxides
other than silica
Lead 6.2988 3.8 5 Metal joining, radiation
shield/CRT, PWB
Aluminum 14.1723 8.5 80 Structural,
conductivity/housing,
CRT,PWB, connectors
Germanium 0.0016 < 0.1 0 Semiconductor/PWB
Gallium 0.0013 < 0.1 0 Semiconductor/PWB
Iron 20.4712 12.3 80 Structural,
magnetivity/(steel) housing
CRT, PWB
Tin 1.0078 0.6 70 Metal joining/PWB, CRT
Copper 6.9287 4.2 90 Conductivity/CRT, PWB,
connectors
Barium 0.0315 < 0.1 0 In vacuum tube/CRT
Nickel 0.8503 0.51 80 Structural,
magnetivity/(steel) housing,
CRT, PWB
17 E-waste recycling in India
Zinc 2.2046 1.32 60 Battery, phosphor
emitter/PWB, CRT
Tantalum 0.0157 < 0.1 0 Capacitors/PWB, power
supply
Indium 0.0016 < 0.1 60 Transistor, rectifiers/PWB
Vanadium 0.0002 < 0.1 0 Red phosphor emitter/CRT
Terbium 0 0 0 Green phosphor activator,
dopant /CRT, PWB
Beryllium 0.0157 < 0.1 Thermal conductivity/PWB,
connectors
Gold 0.0016 < 0.1 99 Connectivity,
conductivity/PWB,
connectors
Europium 0.0002 < 0.1 0 Phosphor activator/PWB
Titanium 0.0157 < 0.1 0 Pigment, alloying
agent/(aluminum),housing
Ruthenium 0.0016 < 0.1 80 Resistive circuit/PWB
Cobalt 0.0157 < 0.1 85 Structural, magnetivity
/(steel) housing, CRT, PWB
Palladium 0.0003 < 0.1 95 Connectivity,
conductivity/PWB,
connectors
Manganese 0.0315 < 0.1 0 Structural,
magnetivity/(steel) housing,
CRT, PWB
Silver 0.0189 < 0.1 98 Conductivity/PWB,
connectors
Antinomy 0.0094 < 0.1 0 Diodes/housing, PWB, CRT
Bismuth 0.0063 < 0.1 0 Wetting agent in thick
film/PWB
Chromium 0.0063 < 0.1 0 Decorative, hardener/(steel)
housing
18 E-waste recycling in India
Cadmium 0.0094 < 0.1 0 Battery, glu-green phosphor
emitter/housing, PWB, CRT
Selenium 0.0016 0.00096 70 Rectifiers/PWB
Niobium 0.0002 < 0.1 0 welding allow/housing
Yttrium 0.0002 < 0.1 0 Red phosphor emitter/CRT
Rhodium 0 50 thick film conductor/PWB
Platinum 0 95 Thick film conductor/PWB
Mercury 0.0022 < 0.1 0 Batteries, switches/housing,
PWB
Arsenic 0.0013 < 0.1 0 Doping agents in
transistors/PWB
Silica 24.8803 15 0 Glass, solid state
devices/CRT,PWB
E-waste and its effect on health and the environment
E-waste cannot be considered or treated like any kind of waste, because it contains hazardous and
toxic substances such as lead, mercury, cadmium or others such as dioxins and furans, bromined
flame retardants (produced when e-waste is incinerated). For instance, lead represents 6% of the total
weight of a computer monitor. Another example: nearly 36 chemical elements are
Incorporated in electronic equipment. This data further demonstrates the un-sustainability of
irresponsible electronic equipment disposal, its negative effect on the environment and the need to
implement management regulations which include actions like refurbishment and recycling.
Even though in the last years recycling has become a regular practice almost everywhere in the
world, some e-waste components present difficulties when they are recycled mainly because of their
complexity and the lack of methods. Such is the case of plastics used in electronic equipment which
contain flame retardants that impede the recycling process. In order to amplify the information
submitted in the web page “We Re-cycle” following is a more detailed description of electronic
equipment components effects on human health and the environment.
Table-2 Products and Health Effects of E-Waste
19 E-waste recycling in India
name of
chemicals
Characteristics Effects on Humans Impacts on the
Environment
Polychlorinated
Biphenyl (PCB)
Can be present in
condensers and
transformers of old
electronic
equipment because of
its properties as cooler,
lubricant and its
resistance to high
temperatures.
Humans are exposed
through contaminated
food consumption or
direct contact at their
workplace,
(e.g inadequate
disassembly of electronic
equipment). Exposure to
this compound can cause
anemia, damages to the
skin, liver, stomach and
thyroid. Contamination of
pregnant women is very
risky and research results
show that it can be
carcinogen
This chemical compound
could drip through
subsurface layers reaching
water and contaminating
it if buried in landfills.
Because it is poorly
soluble, it is very
dangerous when it enters
water currents as it could
contaminate the chain of
production of some foods.
Tetra Bromo
Bisphenol-A
(TBBPA)
TBBA is a flame-
retardant, which is
use in computer
motherboards. This
compound represents
50% of all
bromined flame-
retardants produced
worldwide. 96% of all
motherboards
use this chemical
compound which
represents 1 to 2% of
their weight
It has not been prove that
it can cause mutations or
carcinogen effects on
human beings.
Nevertheless, it has been
prove that TBBA may
interfere in the transport
and metabolism of some
hormones. A technical
study has demonstrated
that there is a direct
correlation between TBBA
in the blood flow and in
the air. TBBA is toxic to
Unlike other flame-
retardants, TBBA when
used as a reactive, bounds
chemically to plastic or
polymers for protection.
This impedes its liberation
into the environment. It is
biodegradable but one of
the products of this
biodegradation is
bisphenol, which can
cause damages to the
endocrine system. The
fact that TBBA dissolves
20 E-waste recycling in India
aquatic organisms poorly in water and tends
to adhere to soil, where it
can reach food, has
created great concern
because TBBA levels
magnify while passing
through the food chain
from 20 to 3200 times.
Polybrominated
Biphenyls (PBB)
Originally, this
substance was add to
plastics of electronic
equipment for
inflammability
reduction. Nevertheless,
PBB production in the
US was stop in 1976 and
in the world in 2000.
Exposure to this
substance can damage
kidneys, liver and
thyroids. Fetuses that
were expose to PBB had
endocrinal problems.
Likewise it is suspected
that PBB is carcinogen
PBB dissolves poorly in
water but can
adhere strongly to soil,
through which it could
reach food. It keeps
magnifying while passing
along the food chain.
Polybrominated
Diphenyl Ethers
(PBDE)
PBDE is another
brominates flame-
retardant with its
number of bromine
atoms varying up to 209
times. Three types are
sold for commercial use
referred to as pent, octa
and deca, two of them
used in electronic
equipment: octa, used
in high impact housings,
and deca used in wire
insulation. Even though
the production of this
Since it was tested for the
first time in 1970, PBDE
was found in numerous
samples of human tissue,
and with increasing
concentrations of factor
100 in the last 30 years.
Exposure can occur the
moment that plastics
containing this substance
are recycled. Concerns for
human health arise
because PBDE containing
4 to 6 brominated
molecules that can act as
PDBE is easily liberated
into the
environment and, like
other flameretardants,
dissolves poorly in water
and strongly adheres to
soil, crossing to
organisms, animals, and
food. This crossing
depends on the
brominated concentration
level; the lower it is, the
more toxic PDBE gets (for
example when exposed to
UV Light). This compound
21 E-waste recycling in India
compound has
decreased since 1999 its
presence in the
environment is
increasing, becoming a
global problem.
thyroxin, damaging the
endocrine system.
Exposed children show
thyroid damages and
neurological anomalies.
is almost omnipresent, as
it is found both in sea and
fresh water organisms,
mammals, birds and water
and soil samples. When
PBDE is incinerated, it
produces dioxins and
furans.
Chlorofluorocarb
ons (CFC)
CFC are used in aerosol
propellants,
cleansing agents,
foaming agents, and
other packaging
materials like solvents
and refrigerants. In
1987, a prohibition
campaign was initiated
reaching its
objective in 1996, an
objective that
developing countries
aim to reach in
2010.
There are no significant
impacts on human health.
Nevertheless there are
indirect negative effects.
Fir example, the release
of CFC attacks levels of
the atmosphere
When in contact with the
ozone layer, CFC destroys
it. One chlorine atom is
responsible for the
destruction of 100.000
ozone molecules. The
ozone layer protects earth
from radiation which
causes skin cancer and
blindness in living beings
Polyvinyl chloride
(PVC)
PVC plastic is used as an
insulator in
certain types of wiring in
electronic
equipment. Risks arise
from vinyl
chloride since this
compound is toxic and
the DEHP used to soften
In the amounts present in
the environment, there is
no proof that DEHP
causes damage to humans
beings but it been proven
that it can damage to lab
animal kidneys. Recent
debates about this
compound suggest that it
This compound is
disseminated in the
environment because of
its extended usage, being
soluble in water if oils or
grease are present. Bonds
easily with soil but also
degrades easily in contact
with
22 E-waste recycling in India
PVC
carries great risks to
human health
can cause endocrine and
gender anomalies in
embryos
oxygen.
Arsenic (As) Arsenic is present in
small amounts
inelectronic equipment
in forms such as Gallium
Arsenide Gas, which
hassemiconductor
properties and can
befound in electronic
equipment diodes.
Gas is carcinogen and
causes skin and lung
cancers. The most
common means of
exposure is direct contact
with dust containing this
compound especially by
workers of semiconductor
manufacturers.
Gallium Arsenide is an
inorganic compound with
low water solubility. It is
transformed into an
organic compound when
bio-accumulated in fish
and crustaceans.
Barium (Ba) Barium is generally use
in cathode
ray tubes (CRT) in
computer monitors.
When functioning in the
monitor this
metal reacts with CO,
CO2, N2, O2,
H2O y H2 which
produces a series of
barium compounds
including oxides,
hydroxides and
carbonates.
Barium compounds’
toxicity is link to its
solubility in water. Some
of these compounds
produced in monitors are
extremely soluble. Intake
of these compounds can
cause gastrointestinal
disorders and muscle
weakness. Higher doses
can cause changes in
heart beat rate, paralysis
and death. Direct contact
with dust containing
barium can cause eye and
skin irritation.
Its impact on the
environment depends on
its solubility. Barium
compounds that are
highly soluble in water are
very mobile and tend to
cumulate in aquatic
organisms
Beryllium (Be) Beryllium is a metal that
generally
forms alloys with copper
to increase its
Beryllium is only
dangerous if inhaled, as
dust or fumes, which
could occur when
This metal doesn’t
dissolve in water and it
remains into soil
23 E-waste recycling in India
endurance, conductivity
and elasticity. Initially,
Beryllium was used in
the production of
motherboards but its
major usage is in
contact circuits,
relays and in some laser
printer
mechanisms
electronic equipment is
disassembled, burned or
crushed. Its inhalation can
cause pneumonia,
respiratory inflammation
(chronic illness of
Beryllium) and can raise
the risk of lung cancer
Cadmium (Cd) Cadmium is a heavy
metal included in many
electronic components,
such as
contact plates, switches,
or used to
prevent corrosion.
Cadmium is particularly
found in chip resistors,
infrared detectors, and
semiconductors. Old
monitors contain
around 5 to 10 grams of
Cadmium and some
batteries are made of
Nickel Cadmium. It is
added as a plastic
stabilizer and pigment
to wiring,
motherboards, pcs,
monitors and printed
circuit boards.
Cadmium exposure
commonly occurs through
inhalation and ingestion
of food or contaminated
water. Inhaling large
amounts of Cadmium can
cause lung damage and
death. Exposure to small
amounts over a long
period of time can cause
high pressure and kidney
damage. This metal is
arcinogen.
Cadmium enters the
environment through
water and soil that is
absorbed by plants. Low
concentrations can cause
alterations in the ecology
and balance of soil
nutrients. This metal can
bio-accumulate in
mushrooms, oysters,
shrimps, mussels and fish.
24 E-waste recycling in India
Chromium VI
(Cr+6)
Chromium VI, i.e.
chromium ions with a
charge of +6, is
chromium’s only toxic
form. Its presence is
small in electronic
equipment where it is
used as a plastic
hardener and protection
layer for some metal
components. When
electronic components
are burned, 99% of
Chromium VI stays in
residuals and ashes,
contaminating soil in a
toxic way, which could
reach water currents
with significant higher
risk.
The effect of this
compound on humans
depends on the type of
exposure. For example,
inhalation can cause
catarrh, nose bleeding,
ulcers and sinus
perforations. Ingestion of
contaminated water and
food can damage the
stomach, kidneys, liver
and cause ulcers,
convulsions and even
death. If there is a direct
contact with skin it can
cause ulcers. This metal is
carcinogen only when
inhaled.
Chromium VI is hardly
found in nature. Its
presence in the
environment (air) is
attributed to industrial
plant emissions, fuel
combustion in commercial
and residential zones.
Lead (Pb) Lead is found in many
electronic
equipment components.
For example,
in a PC, the largest
amount of this
metal is found in the
CRT of the
monitor: 0 to 3% in the
panel, 70% in
the frit, 24% in the
funnel and 30% in the
Humans are exposed to
this metal by particle
inhalation and through
contaminated foods. The
first effects and symptoms
of lead exposure are
anorexia, muscle pain,
malaise and headache but
an extended exposure can
cause a decrease in
nervous system
performance, weakness,
The chemical structure of
this metal is directly
affected by its pH but
most lead compounds are
insoluble in water and
remain in that state. They
are difficultly accumulated
in plants or transferred to
food. Lead doesn’t bio-
accumulate in fish but it
does in other seafood. If
broken or incinerated to
25 E-waste recycling in India
neck. Lead is also
present in
weldings (40%),
motherboards, circuits
and wiring plastic.
brain damage and even
death. Likewise, it can
affect the reproductive
system both in men and
women and is considered
carcinogen.
the environment, particles
will be transmitted by air
and soil.
Lithium (Li) Lithium is present in
computer batteries and
modern electronic
equipment. Typically
batteries contain an
anode of lithium or
lithium oxide, a
magnesium dioxide
(magnesium oxide and
carbon) cathode and
lithium salt dissolved in
an organic solvent. This
type of batteries
replaces alkaline and
NiCd batteries. It is
environmentally more
sustainable than its
predecessors.
Lithium doesn’t cause
toxicological problems as
lead, cadmium or mercury
do. But, a great risk exists
for workers that have a
direct contact. Lithium is
classified as a corrosive
alkali that can burn skin,
eyes and, if inhaled, lungs.
To avoid these risks
lithium batteries must not
be exposed to hot
environments or broken,
factors that can cause the
battery to explode.
Not many studies about
the effects oflithium on
the environment have
beenpublished. These
compounds tend to stay
dissolved in water and
they aren’t easily
absorbed through soil.
Mercury (Hg) Mercury is found in
three specific
places in a computer.
The largest
amount is found in LCD
screen
fluorescent light,
computer or monitor
All forms of mercury
represent a risk to human
health, but mercury in
metal form that is not
combined with other
components and organic
methyl mercury are the
ones that possess the
The impact of mercury on
the environment has been
thoroughly studied.
Mercury in pure form is
extremely volatile and
mining, incineration and
manufacture release this
compound to the
26 E-waste recycling in India
switches, which enable
them to shut
down while idle, and
finally in batteries.
Mercury is very volatile
and easily liberated by
incineration or breaking,
which could liberate up
to 90% of the mercury
contained in the
monitor screen, for
example.
greater risk, especially to
the nervous system.
Short-term exposures to
this compound cause lung
damage, nausea,
vomiting, diarrhea, high
pressure, and, skin and
eye irritation. Long or
permanent exposure
might cause permanent
damages to the brain,
kidneys and fetus
development, besides
neurological changes,
irritability, tremors, short-
sightedness, deafness,
memory problems,
delirium, hallucinations
and suicidal tendencies.
atmosphere. When
mercury, in any of its
forms, gets in contact with
water or soil, turns into
organic methyl mercury
by bacteria action. In
organic form mercury is
more accessible to living
organisms and food. Many
studies have shown
mercury presence in fish,
causing great concern in
many regions worldwide.
Níckel (Ni) Nickel is present in the
batteries of
some electronic
equipment (NiCd),
which are being
gradually replaced
with lithium batteries.
Likewise, nickel
is used in CRT of
computer monitors
Nickel causes skin
damages and asthma
symptoms in about 10 to
20% of the population
that has direct contact.
Workers that are exposed
to dust containing nickel
suffer bronchitis and lung
damages. There is
evidence that many nickel
compounds such as nickel
hydroxide are carcinogen
Nickel generally enters the
environment through air.
These particles are then
placed in water and soil,
especially if they contain
magnesium and steel.
Nevertheless, this
compound does not bio-
accumulate in living
organisms.
Antimony (Sb) Antimony is present in Elevated exposure to Antimony released into
27 E-waste recycling in India
electronic
equipment in small
quantities.
Antimony trioxide is
added to plastic as a
flame-retardant. This
compound is also used
in the CRT glass of
monitors and wire
welding.
antimony via electronic
equipment is unlikely.
Experiments in animals
have emonstrated that
short-term exposure can
cause eye and skin
irritation, hair loss, lung
and heart damages, and
fertility problems.
Antimony trioxide is
considered as possibly
carcinogen
the environment is
commonly found in soil
and sediments. Its
mobility greatly depends
on soil structure, the form
which it takes, and its pH.
This element is better
absorbed in soils
containing steel,
magnesium or aluminum.
Zinc Sulfide (ZnS) Zinc Sulfide is mixed
with other metals
to create a phosphor
coating, which is
used in the inside of the
monitor glass.
Exposure to this
compound happens
when the monitor
breaks.
This element is corrosive
to the skin and lungs and
its ingestion can be very
harmful because it forms
a toxic gas (hydrogen
sulfide) within the
stomach
Zinc is one of the most
common minerals in
nature.
28 E-waste recycling in India
9. Life Cycle of E-waste.
To ensure proper and nearly complete collection of used electronic equipments after they are
rendered useless, it is important to study the processes, which the equipment has undergone. That is
to say, the study of the life cycle of the equipment is equally relevant. The Fig. 5 shows the life span
of electronic equipments, taking into account that it may have switched users during the course of its
operational life. This course will have to be considered for effective collection so that maximum or
all of the E-Waste can be recycled.
For instance, computer hardware would appear to have up to 3 distinct product lives: the original life
or first product life (when it is being used by the primary user) and up to 2 further lives depending on
reuse. Fig. 5 depicts the flow of computer hardware units from point-of-sale to the original purchaser
and on to the reuse phases. The duration of the product’s first life is estimated to be between 2 and 4
years for corporate users and between 2 and 5 years for domestic users. The life cycle of computer
29 E-waste recycling in India
waste is defined as, the period from when it is discarded by the primary user to when it goes for
recycling or is disposed of in a landfill.
Product manufacturer
Material recycling
Primary user second user third/fourth user landfill
Fig-4Flow of E-waste During Its Life Cycle
10. MANAGEMENT OF E-WASTES
It is estimated that 75% of electronic items are stored due to uncertainty of how to manage it. These
electronic junks lie unattended in houses, offices, warehouses etc. and normally mixed with
household wastes, which are finally disposed off at landfills. This necessitates implementable
management measures.
In industries management of e-waste should begin at the point of generation. This can be done by
waste minimization techniques and by sustainable product design. Waste minimization in industries
involves adopting:
inventory management,
production-process modification,
volume reduction,
recovery and reuse.
10.1.Inventory management
30 E-waste recycling in India
Proper control over the materials used in the manufacturing process is an important way to reduce
waste generation (Freeman, 1989). By reducing both the quantity of hazardous materials used in the
process and the amount of excess raw materials in stock, the quantity of waste generated can be
reduced. This can be done in two ways i.e. establishing material-purchase review and control
procedures and inventory tracking system.
Developing review procedures for all material purchased is the first step in establishing an inventory
management program. Procedures should require that all materials be approved prior to purchase. In
the approval process all production materials are evaluated to examine if they contain hazardous
constituents and whether alternative non-hazardous materials are available.
Another inventory management procedure for waste reduction is to ensure that only the needed
quantity of a material is ordered. This will require the establishment of a strict inventory tracking
system. Purchase procedures must be implemented which ensure that materials are ordered only on
an as-needed basis and that only the amount needed for a specific period of time is ordered.
Production-process modification
Changes can be made in the production process, which will reduce waste generation. This reduction
can be accomplished by changing the materials used to make the product or by the more efficient use
of input materials in the production process or both. Potential waste minimization techniques can be
broken down into three categories:
i) Improved operating and maintenance procedures,
ii) Material change and
iii)Process-equipment modification.
Improvements in the operation and maintenance of process equipment can result in significant waste
reduction. This can be accomplished by reviewing current operational procedures or lack of
procedures and examination of the production process for ways to improve its efficiency. Instituting
standard operation procedures can optimise the use of raw materials in the production process and
reduce the potential for materials to be lost through leaks and spills. A strict maintenance program,
31 E-waste recycling in India
which stresses corrective maintenance, can reduce waste generation caused by equipment failure. An
employee-training program is a key element of any waste reduction program. Training should
include correct operating and handling procedures, proper equipment use, recommended
maintenance and inspection schedules, correct process control specifications and proper
management of waste materials.
Hazardous materials used in either a product formulation or a production process may be replaced
with a less hazardous or non-hazardous material. This is a very widely used technique and is
applicable to most manufacturing processes. Implementation of this waste reduction technique may
require only some minor process adjustments or it may require extensive new process equipment.
For example, a circuit board manufacturer can replace solvent-based product with water-based flux
and simultaneously replace solventvapor degreaser with detergent parts washer.
Installing more efficient process equipment or modifying existing equipment to take advantage of
better production techniques can significantly reduce waste generation. New or updated equipment
can use process materials more efficiently producing less waste. Additionally such efficiency
reduces the number of rejected or off-specification products, thereby reducing the amount of
material which has to be reworked or disposed of. Modifying existing process equipment can be a
very cost-effective method of reducing waste generation. In many cases the modification can just be
relatively simple changes in the way the materials are handled within the process to ensure that they
are not wasted. For example, in many electronic manufacturing operations, which involve coating a
product, such as electroplating or painting, chemicals are used to strip off coating from rejected
products so that they can be recoated. These chemicals, which can include acids, caustics, cyanides
etc are often a hazardous waste and must be properly managed. By reducing the number of parts that
have to be reworked, the quantity of waste can be significantly reduced.
Volume reduction
Volume reduction includes those techniques that remove the hazardous portion of a waste from a
non-hazardous portion. These techniques are usually to reduce the volume, and thus the cost of
disposing of a waste material. The techniques that can be used to reduce waste-stream volume can be
divided into 2 general categories: source segregation and waste concentration. Segregation of wastes
32 E-waste recycling in India
is in many cases a simple and economical technique for waste reduction. Wastes containing different
types of metals can be treated separately so that the metal value in the sludge can be recovered.
Concentration of a waste stream may increase the likelihood that the material can be recycled or
reused. Methods include gravity and vacuum filtration, ultra filtration, reverse osmosis, freeze
vaporization etc.
For example, an electronic component manufacturer can use compaction equipments to reduce
volume of waste cathode ray-tube.
Recovery and reuse
This technique could eliminate waste disposal costs, reduce raw material costs and provide income
from a salable waste. Waste can be recovered on-site, or at an off-site recovery facility, or through
inter industry exchange. A number of physical and chemical techniques are available to reclaim a
waste material such as reverse osmosis, electrolysis, condensation, electrolytic recovery, filtration,
centrifugation etc. For example, a printed-circuit board manufacturer can use electrolytic recovery to
reclaim metals from copper and tin-lead plating bath.
However recycling of hazardous products has little environmental benefit if it simply moves the
hazards into secondary products that eventually have to be disposed of. Unless the goal is to redesign
the product to use nonhazardous materials, such recycling is a false solution.
Sustainable product design
Minimization of hazardous wastes should be at product design stage itself keeping in mind the
following factors*
Rethink the product design: Efforts should be made to design a product with fewer amounts
of hazardous materials. For example, the efforts to reduce material use are reflected in some
new computer designs that are flatter, lighter and more integrated. Other companies propose
centralized networks similar to the telephone system.
Use of renewable materials and energy: Bio-based plastics are plastics made with plant-
based chemicals or plant-produced polymers rather than from petrochemicals. Bio-based
33 E-waste recycling in India
toners, glues and inks are used more frequently. Solar computers also exist but they are
currently very expensive.
Use of non-renewable materials that are safer: Because many of the materials used are non-
renewable, designers could ensure the product is built for re-use, repair and/or
upgradeability. Some computer manufacturers such as Dell and Gateway lease out their
products thereby ensuring they get them back to further upgrade and lease out again.
11. Waste management concepts:
The waste hierarchies there are a number of concepts about waste management, which vary in their
usage between countries or regions. The waste hierarchy:
reduce
reuse
recycle
Classifies waste management strategies according to their desirability. The waste hierarchy has
taken many forms over the past decade, but the basic concept has remained the cornerstone of most
waste minimization strategies. The aim of the waste hierarchy is to extract the maximum practical
benefits from products and to generate the minimum amount of waste. Some waste management
experts have recently incorporated a 'fourth R': "Re-think", with the implied meaning that the present
system may have fundamental flaws, and that a thoroughly effective system of waste management
may need an entirely new way of looking at waste.
34 E-waste recycling in India
Some "re-think" solutions may be counter-intuitive, such as cutting fabric patterns with slightly
more "waste material" left -- the now larger scraps are then used for cutting small parts of the
pattern, resulting in a decrease in net waste. This type of solution is by no means limited to the
clothing industry. Source reduction involves efforts to reduce hazardous waste and other materials
by modifying industrial production.
Source reduction methods involve changes in manufacturing technology, raw material inputs, and
product formulation. At times, the term "pollution prevention" may refer to source reduction.
Another method of source reduction is to increase incentives for recycling. Many communities in the
United States are implementing variable rate pricing for waste disposal (also known as Pay as You
Throw - PAYT) which has been effective in reducing the size of the municipal waste stream. Source
reduction is typically measure by efficiencies and cutbacks in waste. Toxics use reduction is a more
controversial approach to source reduction that targets and measures reductions in the upstream use
of toxic materials.
Toxics use reduction emphasizes the more preventive aspects of source reduction but due to its
emphasis on toxic chemical inputs, has been oppose more vigorously by chemical manufacturers.
Resource recovery
A relatively recent idea in waste management has been to treat the waste material as a resource to be
exploited, instead of simply a challenge to be managed and disposed of. There are a number of
different methods by which resources may be extracted from waste: the materials may be extracted
and recycled, or the calorific content of the waste may be converted to electricity.
The process of extracting resources or value from waste is variously referred to as secondary
resource recovery, recycling, and other terms. The practice of treating waste materials as a resource
is becoming more common, especially in metropolitan areas where space for new landfills is
becoming scarcer.
There is also a growing acknowledgement that simply disposing of waste materials is unsustainable
in the long term, as there is a finite supply of most raw materials. There are a number of methods of
35 E-waste recycling in India
recovering resources from waste materials, with new technologies and methods being developed
continuously.
In some developing nations some resource recovery already takes place by way of manual laborers
who sift through un-segregated waste to salvage material that can be sold in the recycling market.
These unrecognized workers called waste pickers or rag pickers, are part of the informal sector,
but play a significant role in reducing the load on the Municipalities' Solid Waste Management
departments.
There is an increasing trend in recognizing their contribution to the environment and there are efforts
to try and integrate them into the formal waste management systems, which is proven to be both cost
effective and also appears to help in urban poverty alleviation. However, the very high human cost
of these activities including disease, injury and reduced life expectancy through contact with toxic or
infectious materials would not be tolerate in a developed country.
Recycling
Recycling means to recover of other use a material that would otherwise be consider waste.
The popular meaning of ‘recycling’ in most developed countries has come to refer to the widespread
collection and reuse of various everyday waste materials. They are collected and sorted into common
groups, so that the raw materials from these items can be used again (recycled).
In developed countries, the most common consumer items recycled include aluminum beverage
cans, steel, food and aerosol cans, HDPE and PET plastic bottles, glass bottles and jars, paperboard
cartons, newspapers, magazines, and cardboard. Other types of plastic (PVC, LDPE, PP, and PS) are
also recyclable, although not as A materials recovery facility, where different materials are separated
for recycling commonly collected. These items are usually composed of a single type of material,
making them relatively easy to recycle into new products.
The recycling of obsolete computers and electronic equipment is important, but more costly due to
the separation and extraction problems.
36 E-waste recycling in India
Electronic waste is send to Asia, where recovery of the gold and copper can cause environmental
problems Recycled or used materials have to compete in the marketplace with new (virgin)
materials.
The cost of collecting and sorting the materials often means that they are equally or more expensive
than virgin materials. This is most often the case in developed countries where industries producing
the raw materials are well established. Practices such as trash picking can reduce this value further,
as choice items are removing (such as aluminum cans).
In some countries, recycling programs are subsidized by deposits paid on beverage containers. The
economics of recycling junked automobiles also depends on the scrap metal market except where
recycling is mandated by legislation (as in Germany). However, most economic systems do not
account for the benefits to the environment of recycling these materials, compared with extracting
virgin materials. It usually requires significantly less energy, water and other resources to recycle
materials than to produce new materials. For example, recycling 1000 kg of aluminum cans saves
approximately 5000 kg of bauxite ore being mined (source: ALCOA Australia) and prevents the
generation of 15.17 tones CO2eq greenhouse gases; recycling steel saves about 95% of the energy
used to refine virgin ore (source: U.S. Bureau of Mines).
In many areas, material for recycling is collect separately from general waste, with dedicated bins
and collection vehicles. Other waste management processes recover these materials from general
waste streams. This usually results in greater levels of recovery than separate collections of
consumer-separated beverage containers, but are more complex and expensive.
Waste management techniques
Managing municipal waste, industrial waste and commercial waste has traditionally consisted of
collection, followed by disposal. Depending upon the type of waste and the area, a level of
processing may follow collection. This processing may be to reduce the hazard of the waste, recover
37 E-waste recycling in India
material for recycling, produce energy from the waste, or reduce it in volume for more efficient
disposal.
Landfill:
Disposing of waste in a landfill is the most traditional method of waste disposal, and it remains a
common practice in most countries. Historically, landfills were often established in disused quarries,
mining voids or borrow pits.
A properly-designed and well-managed landfill can be a hygienic and relatively inexpensive method
of disposing of waste materials in a way that minimizes their impact on the local environment.
Older, poorly-designed or poorly-managed landfills can create a number of adverse environmental
impacts such as
Wind-blown litter,
Attraction of vermin, and
Generation of leach ate which can pollute groundwater and surface water.
Another byproduct of landfills is landfill gas (mostly composed of methane and carbon dioxide),
which is produced as organic waste breaks down an aerobically. This gas can create odor problems,
kill surface vegetation, and is a greenhouse gas.
Design characteristics of a modern landfill are:-
Include methods to contain leach ate, such as clay or plastic lining material.
Disposed waste is normally compacted to increase its density and stabiles the new landform,
covered to prevent attracting vermin (such as mice or rats) and reduce the amount of wind-
blown litter. landfills also landfill compaction vehicles in operation have a landfill gas
extraction system installed after closure to extract the landfill gas generated by the
decomposing waste materials.
Gas is pumped out of the landfill using perforated pipes and flared off or burnt in a gas
engine to generate electricity.
38 E-waste recycling in India
Even flaring the gas is a better environmental outcome than allowing it to escape to the
atmosphere, as this consumes the methane, which is a far more potent greenhouse gas than
carbon dioxide.
Many local authorities, especially in urban areas, have found it difficult to establish new landfills
due to opposition from owners of adjacent land. Few people want a landfill in their local
neighborhood. As a result, solid waste disposal in these areas has become more expensive as
material must be transported further away for disposal.
This fact, as well as growing concern about the impacts of excessive materials consumption, has
given rise to efforts to minimize the amount of waste sent to landfill in many areas. These efforts
include taxing or levying waste sent to landfill, recycling the materials, converting material to
energy, designing products that use less material, and legislation mandating that manufacturers
become responsible for disposal costs of products or packaging. A related subject is that of industrial
ecology, where the material flows between industries is studied. The by-products of one industry
may be a useful commodity to another, leading to a reduced materials waste stream.
Some futurists have speculated that landfills may one day be mined: as some resources become
scarcer, they will become valuable enough that it would be economical to 'mine' them from landfills
where these materials were previously discarded as valueless. A related idea is the establishment of a
'mono-fill' landfill containing only one waste type (e.g. waste vehicle tyres), as a method of long-
term storage.
Incineration:
Incineration is a waste disposal method that involves the combustion of waste at high temperatures.
Incineration and other high temperature waste treatment systems are described as "thermal
treatment". In effect, incineration of waste materials converts the waste into heat, gaseous emissions,
and residual solid ash.
39 E-waste recycling in India
Other types of thermal treatment include pyrolysis and gasification. A waste-to-energy plant (WtE)
is a modern term for an incinerator that burns wastes in high-efficiency furnace/boilers to produce
steam and/or electricity and incorporates modern air pollution control systems and continuous
emissions monitors.
This type of incinerator is sometimes called an energy-from-waste (EfW) facility. Incineration is
popular in countries as Japan where land is a scarce resource, as they do not consume as such area as
a landfill.
Sweden has been a leader in using the energy generated from incineration over the past 20 years.
Denmark also extensively uses waste-to-energy incineration in localised combined heat and power
facilities supporting district-heating schemes.
Incineration is carried out both on a small scale by individuals, and on a large scale by industry. It is
recognised as a practical method of disposing of certain hazardous waste materials (such as
biological medical waste), though it remains a controversial method of waste disposal in many
places due to issues such as emission of gaseous pollutants.
Composting and anaerobic digestion :
Active compost heap Waste materials that are organic in nature, such as plant material, food scraps,
and paper products, are increasingly being recycled. These materials are put through a composting
and/or digestion system to control the biological process to decompose the organic matter and kill
pathogens.
The resulting stabilized organic material is then recycled as mulch or compost for agricultural or
landscaping purposes. There are a large variety of composting and digestion methods and
technologies, varying in complexity from simple windrow composting of shredded plant material, to
automated enclosed-vessel digestion of mixed domestic waste. These methods of biological
decomposition are differentiated as being aerobic in composting methods or anaerobic in digestion
methods, although hybrids of the two methods also exist.
40 E-waste recycling in India
Mechanical biological treatment;
Mechanical biological treatment (MBT) is a technology category for combinations of mechanical
sorting and biological treatment of the organic fraction of municipal waste.
MBT is also sometimes termed BMT- Biological Mechanical Treatment however; this simply refers
to the order of processing.
The "mechanical" element is usually a bulk handling mechanical sorting stage. This either removes
recyclable elements from a mixed waste stream (such as metals, plastics and glass) or processes it in
a given way to produce a high calorific fuel given the term refuse derived fuel (RDF) that can be
used in cement kilns or power plants. Systems, which are configure to produce RDF, include
Herhofand Ecodeco. It is a common misconception that all MBT processes produce RDF. This is not
the case. Some systems such as Arrow Bio simply recover the recyclable elements of the waste in a
form that can be sending for recycling. Arrow Bio UASB anaerobic digesters, Hiriya, Tel Aviv,
Israel The "biological" element refers to either anaerobic digestion or composting.
Anaerobic digestion breaks down the biodegradable component of the waste to produce biogas and
soil conditioner. The biogas can be use to generate renewable energy. More advanced processes such
as the Arrow-Bio Process enable high rates of gas and green energy production without the
production of RDF. This is facilitate by processing the waste in water. Biological can also refer to a
composting stage.
Here the organic component is treat with aerobic microorganisms. They break down the waste into
carbon dioxide and compost. There is no green energy produced by systems simply employing
composting. MBT is gaining increased recognition in countries with changing waste management
markets where WSN Environmental Solutions has taken a leading role in developing MBT plants.
Pyrolysis & gasification:
Pyrolysis and gasification are two related forms of thermal treatment where waste materials are
heated to high temperatures with limited oxygen availability.
41 E-waste recycling in India
The process typically occurs in a sealed vessel under high pressure. Converting material to energy
this way is more efficient than direct incineration, with more energy able to be recovered and used.
Pyrolysis of solid waste converts the material into solid, liquid and gas products. The liquid oil and
gas can be burn to produce energy or refined into other products.
The solid residue (char) can be further refined into products such as activated carbon.
Gasification is use to convert organic materials directly into a synthetic gas (syn-gas) composed of
carbon monoxide and hydrogen. The gas is then burn to produce electricity and steam. Gasification
is use in biomass power stations to produce renewable energy and heat.
12. Recycling of e-waste
The conventional e-waste processing and recycling is basically a five-step process
1. Generation and Stockpiling
Many different “economic actors” purchase, use, and then stockpile or discard electronic waste.
These range from manufacturers such as MNCs to large and small businesses, households,
institutions, and non-profit organizations.
2. Collection
There are wide varieties of possible collection alternatives for this e-waste. Varieties of entities are
providing these services including the electronics industry, private or nonprofit recycling services,
and the public sector through the solid waste management and recycling infrastructure.
42 E-waste recycling in India
3. Handling & Brokering
The next link in the cycle is the handling and brokering services. Here computers, TVs, monitors and
other collected electronics are consolidated and made ready for processing and/or sorted to
determine what equipment can be refurbished or reused as whole units and what equipment must be
disassembled for commodity processing.
4. Processing
After electronic equipment is dismantling, it is then process into either feedstock for new production
or refurbished into new equipment. Outputs from de-manufacturing activities include scrap
commodities such as glass, plastics, and metals the primary elements from which all electronic
hardware is made. For export, and to a lesser extent national processing markets, there are significant
issues associated with the environmental and health practices of current service providers in this part
of the cycle.
5. Production
The final step in this cycle is to turn the processed commodities or refurbished whole electronics
back into new products for sale and consumption by end users. There are many different players and
industries involved in this production process. The recycling fraction is miniscule compared with the
production of product using virgin materials. The substances procured by recycling may be use for
several purposes, even for manufacturing the very same equipments they were derived from.
Recycling/Recovery System
First of the operations involves dismantling and rapid separation of primary materials. The following
materials are separate for further recycling:
· Material containing copper: Including printer and other motors, wires and cables, CRT yokes,
circuit boards, etc
· Steel: Including internal computer frames, power supply housings, printer parts, washing
machines, refrigerator, etc.
43 E-waste recycling in India
· Plastic: Including housings of computers, printers, faxes, phones, monitors, keyboards, etc.
· Copper: Extracted from transformer and CRT after their dismantling
· Circuit Boards: These come from many applications including computers, phones, disc drives,
printers, monitors, etc. Each of these processes has been described below. Following describes the
conventional way of recycling a personal computer.
Bifurcation of electronic scrap
11.2.1. Printed Circuit Boards (PCBs)
The printed circuit boards contain heavy metals such as antimony, gold, silver, chromium, zinc, lead,
tin and Copper. According to some estimates, there is hardly any other product for which the sum of
the environmental impacts for raw material, industrial refining and production, use and disposal is as
extensive as for printed circuit boards. The methods of salvaging material from circuit boards are
highly destructive and harmful as they involve heating and open burning for the extraction of metals.
Even after such harmful methods are used, only a few of the materials are recovered. The recycling
of circuit boards, drawn from monitors, CPU, disc and floppy drives, printers, etc. involves a number
of steps.
Characteristics of PCB Scrap
PCB scrap is characterise by significant heterogeneity and relatively high complexity, although with
the levels of complexity being somewhat greater for populated scrap boards. As has been seen in
respect of materials composition, the levels of inorganic in particular are diverse with relatively low
levels of precious metals being present as deposited coatings of various thicknesses in conjunction
with copper, solders, and various alloy compositions, non ferrous and ferrous metals. In spite of the
inherent heterogeneity and complexity, there are too many differences in the intrinsic physical and
chemical properties of the many materials and components present in scrap PCBs, and indeed
electronic scrap as a whole, to permit recycling approaches that separate such into their individual
fractions.
44 E-waste recycling in India
The following characteristics ultimately govern mechanical and hydrometallurgical separation and it
is based upon such that current and potential recycling techniques and infrastructures have been
envisaged, developed and implemented:-
Density Differences
Differences in density of the materials contained within scrap PCBs have formed the basis for
separation methods subsequent to their liberation as free constituents. The specific gravity ranges of
typical materials are as shown below:-
Table-3
Materials Specific Gravity Range (g/cm3)
Gold, platinum group, tungsten 19.3 - 21.4
Lead, silver, molybdenum 10.2 - 11.3
Magnesium, aluminium, titanium 1.7 - 4.5
Copper, nickel, iron, zinc 7.0 - 9.0
GRP 1.8 - 2.0
With these densities not being significantly affected by the addition of alloying agents or other
additives, it is predictable that the deployment of various density separation systems available within
the raw materials process industry may be utilized to effect separation of liberated constituents of a
similar size range.
The utilization of density differences for the recovery of metals from PCB scrap has been
investigated on many occasions and air classifiers have been used extensively to separate the non
metallic (GRP) constituents, whilst sink-float and table separation techniques have been utilised to
generate non ferrous metal fractions.
Air techniques that effectively combine the actions of a fluidised bed, a shaking table and an air
classifier, have been successfully implemented in applications involving a diversity of electronic
45 E-waste recycling in India
scrap separations. It is essential, as has been noted, that the feed material must be of a narrow size
range to guarantee effective stratification and separation.
Magnetic and Electrical Conductivity Differences
Ferrous materials may be readily separate with the application of low intensity magnetic separators
that have been well developing in the minerals processing industry.
Many non-ferrous materials in respect of their high electrical conductivity may be separated by
means of electrostatic and eddy current separators. Eddy current separation has been developing
within the recycling industry since strong permanent magnets, such as iron boron- neodymium, have
become available.
Rotating belt type eddy current separation is the most extensively used approach for the recovery of
nonferrous metal fractions. In application, the alternating magnetic fields caused by the rapidly
rotating wheel mounted with alternating pole permanent magnets result in the generation of eddy
currents in non-ferrous metal conductors, which in turn, generate a magnetic field that repels the
original magnetic field.
The resultant force, arising from the repulsive force and the gravitational force permits their
separation from non-conducting materials.
Polyformity
One of the important aspects of both PCB and electronic scrap is the polyformity of the various
materials and components and the effect this can have on materials liberation. It is essential that any
shredding and separation processes take this into account. In eddy current separation, the shape of
conducting components, in addition to their particle sizes and conductivity/density ratios, has a
significant effect on the generated repulsive forces that ultimately govern the separation efficiency.
For instance, multiple induced current loops may be establishing in conductors with irregular shapes
with the induced magnetic fields counteracting each other and reducing the net repulsive force.
46 E-waste recycling in India
Liberation Size
The degree of liberation of materials upon shredding (to cut or tear into small pieces) and
comminuting (to pulverize) is crucial (trying) to the efficiency and effectiveness of any subsequent
separation process in respect of yield, quality of recovered material and energy consumption of the
process.
This is especially critical in mechanical separation approaches. The comminuting of scrap PCBs has
been shows to generate a high level of material liberation and levels as high as 96% to 99% have
been report for metallic liberation after comminuting to sub 5mm particulates. It must noted,
however, that a continual observation from recyclers is that liberation levels such as these are
atypical (not typical) of actual yields and that a fundamental constraint on mechanical processing is
the loss, particularly of precious metal content, that appears to be inherent due primarily to the nature
of many plastic-metal interfaces.
Chemical Reactivity
Hydrometallurgical approaches depend on selective and non-selective dissolution to achieve a
complete solublesation of all the contained metallic fractions within scrap PCBs. Although all
hydrometallurgical approaches clearly benefit from prior comminution this is primarily undertaken
to reduce bulk volume and to expose a greater surface area of contained metals to the etching
(corrosive action of an acid instead of by a burin) chemistry.
Selective dissolution approaches may utilise high capacity etching chemistries based on cupric
chloride or ammonium sulphate for copper removal, nitric acid based chemistries for solder
dissolution and aqua regia for precious metals dissolution, where as non selective dissolution may be
carried out with either aqua regia or chlorine based chemistry.
Electropositivity
Dissolved metals generated via chemical dissolution are present as ionised species within an aqueous
media and may be recovered via high efficiency electrolytic recovery systems.
47 E-waste recycling in India
In the instance of selective dissolution, a single metal is recovered as pure electrolytic grade
material, usually in sheet form; from the spent etching solution with certain etching chemistries
permitting regeneration of the liquors for reuse as etch chemistries. In the instance of selective
dissolution, use may be made of the differing electro-positivity of the contained ionised metallic
species to selective recovery metals at discrete levels of applied voltage.
Disassembly
Disassembly in practice
In the practice of recycling of waste electric and electronic equipment, selective disassembly
(dismantling) is an indispensable process since:
(1) The reuse of components has first priority,
(2) Dismantling the hazardous components is essential,
(3) It is also common to dismantle highly valuable components and high-grade materials such as
printed circuit boards, cables, and engineering plastics in order to simplify the subsequent recovery
of materials.
Most of the recycle plants utilize manual dismantling. The main obstacles preventing automated
disassembly from becoming a commercially successful activity are:
(1) Too many different types of products,
(2) the amount of products of the same type is small,
(3) General disassembly-unfriendly product design,
(4) General problems in return logistics and
48 E-waste recycling in India
(5) Variations in returned amounts of products to be disassembled. Fortunately, research in
the field of product design for disassembly has gained momentum in the past decade.
One good idea is self-disassembly, which is called active disassembly using smart materials
(ADSM). Chiodo reported the application of shape memory polymer (SMP) technology to the active
disassembly of modern mobile phones. The smart material SMP of polyurethane (PU) composition
was employed in the experiments. This method provides a potential dismantling scenario for the
removal of all components if this material was to be developed for surface mount components.
Research into using ADSM in other small electronics also has been done to handle units such as
telephones, cell phones, PCB/component assemblies, cameras, battery chargers, photocopier
cartridges, CRTs, computer casings, mice, keyboards, game machines nd stereo equipment.
Mechanical/physical recycling process
1. Screening:
Screening has not been only utilized to prepare a uniformly sized feed to certain mechanical process,
but also to upgrade metals contents. Screening is necessary because the particle size and shape
properties of metals are different from that of plastics and ceramics.
The primary method of screening in metals recovery uses the rotating screen, or trammel, a unit,
which is widely used in both automobile scrap and municipal solid waste processing. This unit has a
high resistance to blinding, which is important with the diverse array of particle shapes and sizes
encountered in waste. Vibratory screening is also commonly used, in particular at non-ferrous
recovery sites, but wire blinding is a marked problem.
2. Shape separation:
Shape separation techniques have been mainly developed to control properties of particles in the
powder industry. The separation methods were classified into four groups by Furuuchi. The
principles underlying this process makes use of the difference:
(1) The particle velocity on a tilted solid wall,
(2) The time the particles take to pass through a mesh aperture,
49 E-waste recycling in India
(3) The particle’s cohesive force to a solid wall, and
(4) The particles settling velocity in a liquid.
Shape separation by tilted plate and sieves is the most basic method that has been used in recycling
industry. An inclined conveyor and inclined vibrating plate were used as a particle shape separator to
recover copper from electric cable waste printed circuit board scrap and waste television and
personal computers.
3. Magnetic separation:
Magnetic separators, in particular, low-intensity drum separators are widely used for the recovery of
ferromagnetic metals from non-ferrous metals and other non-magnetic wastes. Over the past decade,
there have been many advances in the design and operation of high-intensity magnetic separators,
mainly because of the introduction of rare earth alloy permanent magnets capable of providing very
high field strengths and gradients.
In Table 6, we can see that the use of high-intensity separators makes it possible to separate copper
alloys from the waste matrix. An intense field magnetic separation is achievable at least for the
following three alloy groups
• Copper alloys with relatively high mass susceptibility (Al multi-compound bronze);
• Copper alloys with medium mass susceptibility (Mn multi-compound bronze, special
brass);
• Copper alloys with low mass susceptibility and/or diamagnetic material behavior(Sn and Sn
multi-compound bronze, Pb and Pb multi-compound bronze, brass with low Fe content).
4 Electric conductivity-based separation:
Electric conductivity-based separation separates materials of different electric conductivity (or
resistivity) (Tables 5). There are three typical electric conductivity-based separation techniques:
(1) Eddy current separation,
(2) Corona electrostatic separation, and
50 E-waste recycling in India
(3) Triboelectric (electricity generated by friction) separation.
In the past decade, one of the most significant developments in the recycling industry was the
introduction of Eddy current separators whose operability is base on the use of rare earth permanent
magnets. The separator were initially developed to recover non-ferrous metals from shredded
automobile scrap or for treatment of municipal solid waste, but is now widely used for other
purposes including foundry casting sand, polyester polyethylene terephthalate (PET), electronic
scrap, glass cullet, shredder fluff, and spent pot liner.
Currently, Eddy current separators are almost exclusively used for waste reclamation where they are
particularly suited to handling the relatively coarse sized feeds. The rotor-type electrostatic
separator, using corona charging, is utilised to separate raw materials into conductive and non-
conductive fractions. The extreme difference in the electric conductivity or specific electric
resistance between metals and non-metals supplies an excellent condition for the successful
implementation of a corona electrostatic separation in recycling of waste.
To date, electrostatic separation has been mainly utilized for the recovery of copper or aluminum
from chopped electric wires and cables, more specifically the recovery of copper and precious
metals from printed circuit board scrap Triboelectric separation makes it is possible to sort plastics
depending on the difference in their electric properties (Table 4). For the processing of plastics
waste, research has shown many obvious advantages of triboelectric electrostatic separation, such as
independence of particle shape, low energy consumption, and high throughput
TABLE-4 Mechanical separation processes based on electric characteristics of Materials
Processes Separatio
n
criteria
Principles of separation Sorting task Workable
particle
size
ranges
Eddy current
separation
Electric
conductivi
Repulsive forces exerted in
the electrically conductive
Non-ferrous
metal/nonm
>5mm
51 E-waste recycling in India
ty
and
density
particles due to the
interaction between the
alternative magnetic field
and the Eddy currents
induces by the magnetic field
(Lorentz force)
etal
separation
Corona
electrostatic
separation
Electric
conductivi
ty
Corona charge and
differentiated discharge lead
to different charges of
particles and this to action of
different forces (particularly,
image forces)
Metal/
nonmetal
separation
0.1–5mm
(10mm
for
laminar
particles)
Triboelectric
separation
Dielectric
constant
Tribo-charge with different
charges (+ or −) of the
components cause different
force directions
Separation
of Plastics
(nonconduc
tors)
<5 (10)
mm
5 Density-based separations:
Several different methods are employed to separate heavier materials from lighter ones. The
difference in density of the components is the basis of separation. Table 4 shows that density-based
separation processes have found widespread application in non-metal/metal separation.
Gravity concentration separates materials of different specific gravity by their relative movement in
response to the force of gravity and one or more other forces, the latter often being the resistance to
motion offered by a fluid, such as water or air. The motion of a particle in a fluid is dependent not
only on the particle’s density, but also on its size and shape, large particles being affected more than
smaller ones. In practice, close size control of feeds to gravity processes is required in order to
reduce the size effect and make the relative motion of the particle specific gravity dependent.
52 E-waste recycling in India
TABLE-5 Density separation processes utilized for non-metal/metal separation
Utilized for following sorting tasks
Density
separation
Process
Workable
piece
Sizes
(mm)
Plastics
waste
Aluminum
scrap
Lead
battery
scrap
Cable
scrap
Electronic
scrap
Light
steel
scrap
Sink-float separation
In liquids * * * *
In heavy media
Gravity separator 5–150 * * * *
Hydro cyclone + <50 *
In aero suspensions
In aero chutes 0.7–3 *
In fluidized bed
Trough separators
0.7–5
Sorting by jigging
Hydraulic jigs 2–20 *
Pneumatic jigs <3 *
Sorting in chutes and on tables
Aero-chutes 0.6–2 *
Aero-tables <4 *
Up-stream separation
Up-stream
hydraulic
Separation
5–150 * * *
Up-stream
pneumatic
Separation
<300 *
Mechanical Approaches of recycling electronic scrap
53 E-waste recycling in India
As may be anticipated, all of the work undertaken on mechanical systems has been with the primary
objective of enhancing separation yield of the various fractions, particularly the precious metal
bearing ones.
The basic mechanical techniques deployed in the treatment of scrap PCBs and electronic assemblies
have been adapted or adopted from the raw materials processing sector and refinement has sought to
address both yield constraints and ultimately cost effectiveness either of the approaches, used singly
or in an integrated manner.
The problems associated with yield were apparent from early attempts to produce a model
methodology for handling all types of electronic scrap as instanced by the US Bureau of Mines
(USBM) approach in the late 1970s and early 1980s. The separation route, developed up to a 250 kg
per hour pilot plant, comprised shredding, air separation, and magnetic, eddy current and
electrostatic separation to generate aluminum rich, copper rich (including major precious metal
fraction), light air classified and ferrous fractions.
The yield, however, was such that no commercial uptake of this approach has been instanced. The
relatively poor yields or levels of separation obtained from this approach, were undoubtedly a result
of the use of a standard hammer mill having no provision, or levels of refinement, to cope with clear
comminution (pulverize) of aluminium, the use of a ramp type eddy currentseparator of low capacity
and selectivity and the use of a high tension separator for metals/non metals, which has been since
demonstrated as having low capacity and high susceptibility to humidity.
There was little further meaningful development work on the implementation of mechanical
treatment approaches until the early 1990s when Scandinavian Recycling AB in Sweden
implemented their mechanical concept for electronic scrap handling which did not specifically
address the treatment of scrap PCBs but rather removed PCBs for specialist treatment as part of the
pre sorting stage. Subsequent to this development, work in both Germany and Switzerland has seen
the implementation of mechanically based approaches for the handling and separation of electronic
scrap with the work at FUBA dedicated to scrap PCBs being a notable example of this activity.
54 E-waste recycling in India
In 1996, Noell Abfall and Energietechnik GmbH in Germany implemented a 21,000 tonnes per
annum plant with the capability of handling a wide variety of electronics scrap but specifically
intended for redundant telecommunications scrap. The system again involves PCB scrap and the
inherent precious metal content being subject to prior manual disassembly. The overall methodology
deploys a three stage liberation and sequential separation route with ferromagnetic removal via
overhead permanent magnets and eddy current techniques because of their ability to optimise the
handling of fractions in the 5 to 200 mm particle size range.
Air table techniques were utilised for the separation of particulate fractions in the 5 to 10 mm, 2 to 5
mm and less than 2 mm ranges respectively. Mechanical and physic mechanical approaches to the
treatment of scrap PCBs may be deployed as standalone treatment stages, (i.e. pulverisation,
magnetic separation, or integrated into a complete treatment system with the output being metallic
and non-metallic fractions). The metallic output would be destined for hydrometallurgical
refinement via smelting where as the nonmetallic output would find applications in the secondary
plastics marketplace or be utilised within dedicated developed applications.
As reported, FUBA has developed its total mechanical treatment system, albeit only currently
utilised for nonpopulated board scrap or ancillary laminate waste through this latter route. There are
commercially available turnkey mechanical systems for the treatment of
a wide range of electronic scrap materials including populated and non-populated PCBs. One such is
that developed by hamos GmbH in Germany, which is an automated integrated mechanical system,
comprising the following stages:
• Primary coarse size reduction, accomplished with a shredder having multi-use rotational
knives;
• Coarse ferrous metal separation, accomplished with rare earth magnets sited above an
oscillating conveyor belt feed to allow high efficiency ferrous separation across a range of
particle sizes;
• Pulverisation in which circuit board assemblies are pulverised within a hammer mill
utilising high abrasion resistance hammers and liners and proprietary grates with the action
of the mill inducing a 'spherising' effect on the metallic articulates;
• Classification, utilising self-cleaning sieves;
55 E-waste recycling in India
• Electrostatic separation, allowing virtually complete separation of metallic fractions with
recirculation of mid-range particulate fractions
• Further size reduction, cosisting of secondary pulverisation to effect size reduction on
oversized particulates.
The hamos system can additionally incorporate density separation for aluminium extraction and dust
generation treatment of any such outfall from the hammer mills via secondary electrostatic
separators. The complete conveyor based systems are operated at negative pressures to eliminate any
airborne pollution and are currently available with treatment capabilities up to 4 tonnes per hour of
input feed.
All products from the system viz mixed plastic, metallic and extracted ferrous and aluminium is
bagged automatically for onward shipment. Considerable work has been undertaken on enhancing
the effectiveness of mechanical treatment systems. For example, the development of newer
pulverizing process technology via the application of multiple pulverising rotors and ceramiccoated
systems has enabled the generation of sub-millimetre particulate comminution. This in turn has
enabled the efficiency of subsequent centrifugal separation techniques to realize 97% copper
recovery yields.
The effectiveness of the pulverising process has been improved by the adoption of dual pulverising
stages: a crushing process and a fine pulverising process. The crushing process combines cutting and
shearing forces and the fine pulverising process combines shearing and impact forces. With such
effective particulate comminution both screen separation and gravity separation have been
investigated and conclusions drawn that the most effective approach was by gravity using a
centrifugal classifier with a high air vortex system.
Researchers at Daimler-Benz in Ulm, Germany, have developed a mechanical treatment approach
that has the capability to increase metal separation efficiencies, even from fine dust residues
generated after particulate comminution in the treatment of scrap PCB assemblies. They considered
a purely mechanical approach to be the most cost effective methodology and a major objective of
56 E-waste recycling in India
their work was to increase the degree of purity of the recovered metals such that minimal pollutant
emissions would be encountered during subsequent smelting.
Their process comprises the initial coarse size reduction to ~2 cm x 2 cm dimensioned fractions
followed by magnetic separation for ferrous elements. A low temperature grinding stage then
follows this. The embrittlement of polymeric components at temperatures less than 70°C was found
to enable enhanced separation from non-ferrous metallic components when subjected to grinding
within a hammer mill. In operation the hammer mill was fed with liquid nitrogen at minus 196°C,
which served to both impart brittleness to the plastic feedstock constituent and to effect process
cooling. Additionally, the grinding of material within such an inert atmosphere eliminated any 17
likelihood of oxidative by product formation from the plastics, such as dioxins and furans.
Subsequent to this enhanced grinding stage the metallic and non metallic fractions were separated
via sieving (an instrument with a meshed or perforated bottom, used for separating course from fine
parts of loose matter, for straining liquids) and electrostatic stages. Cost analyses undertaken by
Daimler-Benz engineers have indicated that such a process may be economically viable even when
dealing with relatively low-grade PCB scrap having little precious metal content.
Ongoing activities are concerned with development of the treatment of separated polymeric fractions
in conjunction with Mitsubishi Heavy Industries that have set up a gasification and methanol (a
colorless, volatile, water-soluble, poisonous liquid, CH4O, obtained by the destructive distillation of
wood or the incomplete oxidation of natural gas, or produced synthetically from carbon monoxide
and hydrogen, used chiefly as a solvent, a fuel, and an automobile antifreeze and in the synthesis of
formaldehyde) sis plant to such effect. Air table separation systems have been researched with a
view to effecting separation of metallic and plastic components from an input feed of screened 7 mm
shredded particulate scrap PCBs post ferromagnetic separation. Recovery rates for copper, gold and
silver of 76%, 83% and 91% respectively were considered to validate the approach, but only for low-
grade PCB scrap or general electronic scrap.
Hydrometallurgical Approaches
57 E-waste recycling in India
A number of hydrometallurgical (the technique or process of extracting metals at ordinary
temperatures by leaching ore with liquid solvents)approaches have been developed through to pilot
plant stage with preliminary cost studies indicating the potential recovery of all materials, with the
exception of discrete components, at an operational profit. In the USA, a methodology based on
solvolysis has been developed to enable both the more efficient recovery of metals and the recovery
of plastic materials such as epoxides at high quality and with the additional benefit of having the
capability to extract both halogens and brominated hydrocarbon derivatives. On a relatively small
scale there have been a number of hydrometallurgical approaches traditionally pursued in the
recovery specifically of gold from pins and edge connectors.
Such methodologies have usually been deployed on discrete edge connectors and gold-coated
assemblies that have been manually separated from the scrap board via the use of air knives etc. The
approaches have either liberated gold as metal flake via acidic dissolution of the copper substrates or
dissolution of the gold in cyanide or thiourea based lea chants followed by electro winning or
chemical displacement or precipitation with powdered zinc.
The use of non-selective leachants to dissolve the non precious metal content of scrap PCBs has also
received attention. Various studies have been undertaken into the viability of utilising dilute mineral
acids in conjunction with subsequent metal recovery techniques based on concentration and
separation such as solvent extraction, ion exchange, adsorption and cementation.
In the UK, there have been two potentially significant development projects undertaken on
hydrometallurgical approaches to the recycling of scrap PCBs with both having demonstrated
viability to a pre pilot plant stage.
The first of these approaches is from a Cambridge University led consortium, which deploys a
selective dissolution electrolytic recovery route for discrete metal constituents. The solder recovery
stage employs a solder selective (non copper etching) regenerable leachant based on fluoroboric
acid. This may or may not be deployed prior to mechanical pre treatment, from which the dissolved
solder can be electrolytically recovered in pure metallic form. Subsequent selective leaching of
copper and PMG metals is then carried out. The ability to remove selectively solder prior to
58 E-waste recycling in India
mechanical comminution has specific advantages in enabling disassembly and component integrity
and recovery. Mechanical pre treatment methodologies followed by the Cambridge group have
included shredding, magnetic separation, eddy current separation and classification.
The second development is that of the Imperial College, London (ICL) consortium which has taken
shredded and classified sub 4mm PCB populated PCB scrap through a single leachate route
comprising electro-generated chlorine in an acidic aqueous solution of high chloride ion activity.
This has produced a multi metal leach electrolyte containing all of the available metal content at
generally mass transport controlled rates with respect to dissolved chlorine. The viability of
subsequent metal recovery via electrolytic membrane cells with discrete metal separation has also
been demonstrated. To summarize the above discussions:
• Hydrometallurgical approaches offer a viable methodology in maximising the recovery of
intrinsic metal value, particularly precious metals, and should be further developed through
pilot plant stages to commercialisation.
• No single treatment approach will be appropriate for the handling of all scrap PCBs because
of their diversity and varying intrinsic worth. Rather, an integrated hierarchy of approaches
that encompasses disassembly and mechanical and hydrometallurgical methodologies will be
needed to generate either materials or components for direct reuse or downstream application
or a non-toxic feedstock for pyrolytic refining.
PWB Waste
Crushing process
Pulverising process
59 E-waste recycling in India
Fine pulverising
Gravity Separation
Copper Rich Powder Glass Fiber & Resin
Recycling of copper filler in construction materials
Fig-5 97% recovery of Copper from PWBs
Extraction of IC/ other components from PCB
IC/other components from PCBs are manually extracted as shown in figure This process is common
for PC, TV and cell-phone. The E-waste stream from cell-phone joins the E-waste stream of PC and
TV.
Fig-6 Extraction of IC/ other components from PCB
Recovery of Gold
Gold recovery techniques and hazards
60 E-waste recycling in India
Three processes to recover gold from e-waste are described. The main materials used are determined
and partly quantified. From this information, the major hazard-“hot spots” to health and environment
are identified.
Methodology
The system is described using the material flow analysis (MFA). “Material flow analysis (MFA) is
a systematic assessment of the flows and stocks of materials within a system defined in space and
time.” (Brunner and Rechenberger, 2004). The goal of an MFA is to determine the in- and outputs of
a process and to understand the flows within a system. The analysis of material fluxes is an essential
approach to gain a system comprehension and an understanding of the processes occurring within
the anthrop sphere (Binder et al., 2001). “Because of the law of the conservation of matter, the
results of an MFA can be controlled by a simple material balance comparing all inputs, stocks, and
outputs of a process. It is this distinct characteristic of MFA that makes the method attractive as a
decision-support tool in resource management, waste management, and environmental management”
(Brunner and Rechberger, 2004). In this analysis the used terminology has been developed according
to the terminology defined in the Practical Handbook of Material and Flow Analysis (Brunner and
Rechenberger, 2004).
Subsequent the mainly used terms in this thesis are defined:
A substance is any (chemical) element or compound composed of uniform units. All
substances are characterised by a unique and identical constitution and are thus homogenous.
The term material is use for a solid matter composed of heterogeneous units. A solution is
the product of mixed substances and materials and is a heterogeneous liquid.
A mixture is the product of mixed substances and is a homogeneous liquid.
Process is a term used for the transformation and transport of materials and substances.
A technique is defined to be a sequence of processes.
61 E-waste recycling in India
A process step is an activity within a process (sub-process).
The system is defined by a group of processes, the interaction between these processes and
the system boundaries.
The conducted material flow analysis comprises four steps:
System description: The system is characterised determining the system border and the
single process steps referring to the processes of each technique. Using information from
literature and various experts the processes and process steps of the system are described.
Quantification: The in- and outputs of the system are measured and calculated/estimated
applying the principle of mass conservation.
Interpretation: The environmental hazard hot spots are detected with the beforehand
evaluations and are discussed.
Discussion: An overview of each evaluated system is given. In addition, some features
determined in the description and in the quantification of each process are discussed.
System DescriptionSystem definitionThe investigated system is part of the e-waste management system is illustrated in Figure. It consists
of the gold recovery technique of pre-processed (dismantled) printed wiring boards (PWBs).
62 E-waste recycling in India
The system consists of a gold recovery technique divided in several processes that are required in
order to recover gold from the input material. The technique is divided into three processes:
Leaching, Separation and Purification. In the context of gold extraction, leaching is the dissolution
of a metal or mineral in a liquid (Marsden and House, 1992). During the separation, the gold is
extracted out of a solution or separated from a material. Purification is the procedure of rendering
something pure, i.e. cleaning it from impurities.
63 E-waste recycling in India
The description of the techniques is based on different data sources: Observations, photographs,
documentation, literature research and interviews. techniques are used to recover gold is based on
gold mines from the ore as they are used to recover gold from pre-processed PWBs.
Currently about 20 informal facilities in and around Bangalore are involved in the recovery of
precious metals from e-waste (Rodriguez, 2005). All of them presumably use the same technique to
recover gold. Consultants of GTZ and EMPA are closely working together with an informal
association of recyclers called Eco BIRD. With the help of GTZ and EMPA, it was possible to use
these contacts and to work together with a gold recovery unit of Eco BIRD. The following paragraph
gives a short description of Eco BIRD and the investigated unit.
Eco BIRD
Fig-8 Eco BIRD (Rizwan’s) facility
In the informal sector in Bangalore, a recently founded association consisting of 11 recycling units
called Eco BIRD exists. The word “Eco” stands for “Eco-friendly” and BIRD is an acronym for
Bifurcation, Identification, Recycling and Disposal. The 11 recycling units either deal with scrap,
dismantle the equipment or recover precious metals. The examined facility belongs to Rizwan Khan
(president of Eco Bird) and is situated on a roof (approx. 46m2) in Gowripalya, Padarayanapura, a
suburb of Bangalore. There is a room (approx. 16 m2) on top of the roof, where the furnace is
situated and the materials and substances are stored in. The containers with acidic liquids are placed
outside. Rizwan employs three workers between the age 10 and 20. Several other people are also
using his facility. The material that is treated by Rizwan per year is estimated to be 1800 kg with a
64 E-waste recycling in India
gold production of 7200g (Bineesha, 2006). To recover gold from e-waste two different techniques
are conducted according to the quality of the input material. If the gold concentration in the input
material is low (lowgrade material), “cyanide leaching” is used. If the input material is high-grade
material, they conduct “mercury amalgamation”.
Both of the processes are described in the following :-
Formal sector
In the formal sector, only one company, Surface Chem Finishers, is known conducting a gold
recovery process. It was possible to collaborate with this company and investigate the exercised
process. In the following paragraph a short description and scope of the company is given
Surface Chem Finishers
Fig-9 E-Parisaraa Pvt. Ltd.
“Surface Chem Finishers” is an ISO 9001 – 2000 certified gold plating unit in Peenya Industrial
Estate, Bangalore. It is a sister company of “E-Parisaraa Pvt. Ltd.” Which recycles and dismantles e-
waste. The vision of the director of the two companies is to be eco-friendly and low cost. “E-
Parisaraa” is located on the outskirt of Bangalore. About 5 % of the gold used for the gold plating in
“Surface Chem Finishers” is recovered from ewaste pre-processed at “E-Parisaraa”. Thus, gold
recovery is only a side task of Surface Chem Finishers.
Today there are 45 people working in the two companies. Three persons are involved in the gold
recovery process. At present, E Parisaraa is handling about one ton of e-waste per day. According to
Prakashchandra (Engineer of Surface Chem Finishers, E-Parisaraa Pvt. Ltd.), approximately 920 kg
of material is processed per year to recover gold. Thereof 440 g of gold is recovered per year.
Cyanide leaching at Eco BIRD
65 E-waste recycling in India
Cyanide has been used in the mining industry for more than 100 years to recover gold. It is
universally used because of its relatively low cost and great effectiveness of gold dissolution.
The reaction takes place in an alkaline environment, which is important for economic and safety
reasons. It has been shown that the maximum dissolution of gold, silver, platinum and palladium in
cyanide solution is at pH 10-10.5. The observed cyanide leaching technique was conducted at around
pH 12.
This is almost ideal for the leaching process as the loss of cyanide is very low at pH 11.5 because the
loss due to hydrogen cyanide (HCN) formation is very low. The main chemical reaction consists of
four starting materials and substances: water, oxygen, gold and cyanide.
Cyanide is acting as the complexing agent in the process and oxygen as an oxidiser. However, other
elements contained in the electronic devices disturb this chemical reaction. For example, the present
copper will form cyanide complexes and cause an increased use of cyanide. These copper-cyanide
complexes will tend to inhibit the dissolution of gold.
Detailed description of the techniqueDuring a participating observation, this process had been investigated. The input material is provided
to the informal facility with this material, the process is conducted as it would be conducted with
purchased material and it is therefore an acceptable representative for the “usual” process. In the
following description the denominations (L1… P6) refer to the detailed and quantified flowchart in
Leaching
L 1: Lixiviation
The connectors are put into a plastic container and are doused with hot water. The gold leaching is
initiated by adding substance 1 (most probably potassium or sodium cyanide).Under mildly
oxidising conditions, the gold is dissolved. Adding cyanide results in a strong complex between
cyanide and gold. The reaction known as Elsner's Equation is:
66 E-waste recycling in India
4 Au(s) + 8 CN-(aq) + O2(g) + 2 H2O(l) 4 Au(CN)2-(aq) + 4 OH-(aq)
Because cyanide is one of the strongest ligands several other complexes are formed (ex.: [Ag(CN)2]-,
[Cu(CN)2] -, [Ni(CN)4]-2).
Fig-10 Lixiviation with cyanide
L 2: Sieving / Washing
The components are removed from the pregnant (gold-bearing) solution and are washed with water.
This is important in order to deplete the waste components as good as possible of their gold. These
components are sometimes kept to recover copper in a separate process.
Fig-11 Sieving of components
The pregnant solution has a brownish colour.
Fig-12 Pregnant solution
Preparation of silver-salt
The silver-salt is prepared separately, conducting following process steps:
PS 1: Heating
A silver ingot, nitric acid and hot water are mixed together and heated for approx. 5 minutes to
dissolve the silver. The remaining silver biscuit is then taken out, the solution is poured into a plastic
bucket, and the tin container is washed with water.
67 E-waste recycling in India
Ag + 2 HNO3 -> AgNO3+ NO2 + H2O
Fig-13 Silver nitrate
PS 2: Precipitation
Sodium chloride and water are added to the silver solution. The silver-salt precipitates as silver
chloride, which is a white precipitation. Sodium nitrate has a high solubility in water and is dissolved
in the solution.
AgNO3 + NaCl -> AgCl + NaNO3
PS 3: Decantation
The liquid part of the reaction mixture is poured into another container. Silver chloride remains on
the bottom of the bucket. Hot water is used to clean the remaining slag from the nitric acid by
decantation.
Fig-14 Silver chloride
PS 4: Mixing
Water, an unknown salt and caustic soda are mixed with the white precipitation. The reason for
adding caustic soda (NaOH) is to keep an alkaline environment. After a further decantation, the
silver-salt enters the main process.
Separation
68 E-waste recycling in India
S 1: Gold formation
The separation is performed using the principles of the Merril-Crowe process3 (cementation with
zinc). Aluminium-foils and the silver-salt are added to the gold bearing solution. Aluminium
precipitates the gold and some silver because Al has the higher affinity to the cyanide ion than gold
and silver. The silver reacts with the free cyanide to prevent that the gold is dissolved again.
3 [Au(CN)2]- + 2 Al -> 2 Al3+ + 6 CN- + 3 Au(s)
4 Ag(s) + 8 CN-(aq) + O2(g) + 2 H2O(l) 4 Ag(CN)2-(aq) + 4 OH-(aq)
Fig -15 Adding aluminium
S 2: Decantation / Filtering
The grey sludge is separated from the solution by pouring the solution from one container to the
other and keeping the precipitation in the container. After doing so, the remaining slag is filtered
through a cloth.
Fig-16 Decantation
Fig-17 Filtering the mixture
3 The Merril-Crowe process is a separation technique for removing gold from cyanide solution,
usually using zinc.
69 E-waste recycling in India
Purification
P 1: Melting
The cloth with its content is put into a crucible and is melted. During the melting process lime
(CaCO3) and two unknown substances are added. These substances are flux materials that help to
purify the gold. The purpose of substance 2 is to liberate the aluminium. Lime is then used to remove
the substance 2. Lime precipitates base metals such as aluminium as gelatinous hydroxides.
Substance 3 is added because the quality of the aluminium had been low grade. During the melting
process flux, slag is taken out for grinding.
Fig-19 Melting
Fig-20 Flux slag
P 2: Pouring
The rest of the melted slag is poured into water.
70 E-waste recycling in India
Fig-21 Pouring
P 3 Grinding
The process flux is grinded with an iron ball.
P 4: Boiling
Fig-22 Grinding
The solid (gold) pieces from the “Pouring” and the grinded flux are mixed and boiled to remove the
residual water.
P 5: Partition
Nitric acid is added to separate the silver from gold. Silver nitrate is soluble in water and a gold
material precipitates.
Ag + 2HNO3 -> AgNO3+ NO2 + H2O
Fig-23 Partition of gold and silver
P 6: Melting
The gold material is placed in a crucible and melted. Substance 3 is added to absorb impurities. The
flux slag that hardens is removed mechanically. The remaining material in the crucible is pure,
liquified gold. It is poured out and a button is formed with a hammer ike instrument.
71 E-waste recycling in India
Fig-24 Crucible containing gold after melting
Fig-25 Recovered gold button
The following flowchart illustrates the above-described technique.
Input material
Water Leaching Water vapour
72 E-waste recycling in India
Substances1 Body components
From "silver- Silver-salt Separation Waste solutionsaltpreparation" Preparations Aluminum foils
Water
Cloth Purification
Lime Silver solution2 Ag - recoveryUnknown Water vapoursubstance NitrogenWater dioxide Nitric acid organic waste
Gold
Fig-26 Simplified flowchart of the „cyanide leaching“.
Mercury amalgamation at Eco BIRD
73 E-waste recycling in India
The gold recovery with mercury goes back to the 11th century. In the Middle Ages alchemists tried
to produce gold with base metals (which did not work). The mercury amalgamation is based on the
fact that mercury forms an amalgam4 with gold. With this procedure, the gold can be separated from
the other metals present and from impurities. The attraction of mercury is based on the fact that it is
readily available, cheap and efficient in recovering fine-grained gold (Commission of the European
Communities, 2000). It is a quite simple process using only three substances (mercury, nitric acid
and sodium bicarbonate) to recover the gold. However, it is an old technique and no longer used in
modern gold plants because of the known health and environmental problems arising.
Detailed description of the technique
Leaching
The input material is filled in plastic containers (V=approx. 100l). At first water is poured into the
container, than the nitric acid (62%) is added. Throughout this process, the metals (e.g. Cu) which
are contained in the input material, except gold, are dissolved in the solution. Thus, the attaching
parts of the gold pins to the mold are dissolved and the gold pins and flakes are released. The
dissolving takes about 3 hours. During this time, it is stirred from time to time and nitric acid and
some water are added.
2 NO3- + 4 H+ + Cu -> 2 NO2 ↑+ H2O + Cu++
With a sieve (mesh aperture approx. 4 cm x 4 cm) the remaining components are taken out, washed
with water and kept to process them again in the cyanide leaching process. In the bluish solution,
gold flakes remain and copper is dissolved. The solution is filtered through a cloth to abstract the
gold pins. The remaining solution is then put into a big container to recover the copper by adding an
iron to the liquid. The iron is left in the container for several weeks. At the end, the copper sticks to
the iron and can be removed manually.
Fig-27 Lixiviation
74 E-waste recycling in India
Fig-28 Filtering
4 Amalgam is any mixture or blending of mercury with another metal.
Separation (Amalgamation)
The gold residues are put into a pan, inclusive the cloth used for filtration. Mercury and some drops
of nitric acid are added and mixed in the pan. The resulting alloy of gold and mercury is called
amalgam. The cloth is washed with water and remaining non-gold-components are removed from
the mixture. Sodium Bicarbonate is added to the mixture and the mixture is decanted. The decanted
slag is squeezed through the cloth the excess mercury is recovered. The residue in the cloth is a hard
lump of amalgam with a high concentration of gold. A small amount of mercury and water is added
to the amalgam lump to make it softer. Then the lump is scrunched with a hammer-like instrument.
Fig-29 Goldmercury- amalgam
Purification
Nitric acid is added to the amalgam and the resulting mixture is decanted. Nitric acid dissolves part
of the mercury, which is recovered in a separate process. The decanted mixture is boiled in a
furnace. Because mercury and nitric acid vaporise at a much lower temperature than gold, these two
substances can be removed by heat leaving the gold behind (Beard, 1987). The residual product in
the pan is a yellow gold powder. In a last step, magnetic impurities are sorted out with a magnet.
75 E-waste recycling in India
Fig-30 Nitrogen dioxide during silver dissolving
Fig-31 Recovered gold powder
The following flowchart illustrates the above-described technique.
76 E-waste recycling in India
Connectors
Nitric acid Leaching Gas / Fumes
Water Body components
Copper Solution Copper recovery Separation
Mercury Waste solutionNitric acid WasteWater components
Sodium Mercurybicarbonate Purification
Nitric acid Gas / Fumes
Water Mercury solution Mercury recovery
Gold
Fig-32 Simplified flowchart “ of the mercury amalgamation”.
Gold stripping at Surface Chem Finishers
The director of Surface Chem Finishers developed a gold stripping substance with the goal to
conduct a more environmentally sound process than by using cyanide or mercury. The concept is to
dissolve the gold with the solution and collect it with electrolysis.
77 E-waste recycling in India
Detailed description of the technique
Leaching
The input material is put over night into a substance (gold stripper). During this time, the gold is
eached out of the components. The components are removed from the solution and are washed with
hot water in order to deplete the waste components as good as possible of their gold.
Fig-33 Lixiviation with “gold stripper“
Separation and Purification
The solution is filtered through a “Whatman Filter” and poured into a bucket. The anode and cathode
(titanium) are then put into this bucket. They are connected to a small motor working with 5 V and
0,5 A. Over night, the electrolysis is conducted and the gold is collected at the cathode.
Fig-34 Filtering
The cathode is removed from the solution and dried for 10 min at
178°C.
Fig-35 Electrolysis
78 E-waste recycling in India
The solid gold on the cathode is dissolved with aqua regia (HCl : HNO3= 3 : 1). This step is done
under an exhaust to protect the worker from inhalation of the toxic fumes.
Au + 4 HCl + HNO3 = HAuCl3 + 2 H2O + NO
Fig-36 Dissolving gold in aqua regia
This solution is filtered again through a “Whatman Filter”. Ferrous sulphate is added in order to
precipitate the gold.
Fe+ + Au2+ -> Fe3+ + Au (s)
To accelerate the process the solution is heated. Purple colloids precipitate.
Fig-37 Heating the sulphate solution
The precipitation is then separated by decanting. The remaining material is washed with water
filtered through a “Borosil Glass”. The Glass is put into a heater to dry the material. The result is a
yellow gold powder.
Fig-38 Gold powder after drying
The following flowchart illustrates the above-described technique.
79 E-waste recycling in India
Connectors
Leaching Gold Stripper Vapour
Water Body components (BC)
SeparationAqua regia Waste solution 1Water
PurificationFerrous Wastesulphate solution2 Water
Gold
Fig-39 Simplified flowchart of the “gold stripping”.
Quantification
Data collection
During the observations made for the description of the three gold recovery techniques
measurements were conducted to quantify the in- and outputs of the processes. The in- and outputs
were weighed with an electronic scale, measured with a measuring cup or calculated by multiplying
the volume with the density (assumed to be 1000 g / l). To find out the volume, the diameter of the
cylindrical containers and the height of the contained liquid were measured. According to the
received figures the mass flow could be completed applying the law of conservation of mass (Input =
Output), making feasible assumptions and considering the chemical equations. In a further step the
80 E-waste recycling in India
amounts of in and outputs were converted according to the functional unit “one gram recovered
gold”.
The cyanide leaching and the gold stripping are quantified using provided material.The mercury
amalgamation is only partly quantified during an investigation of the informal facility doing usual
business.
Cyanide leaching at Eco BIRD
The measurements for the different used and produced materials, substances, solutions,
mixtures and vapours are made according to following descriptions:
• All the inputs of this process were measured except the cloth.
• All the liquid outputs and the silver salt (which was also a mixture) were calculated
(volume * density).
• The wet output components were weighed. The estimation was made that the weight of the
dry output components correspond approximately with the weight of the input components
(the amount of leached metals was neglected).
• The amount of “water vapour 1” results from subtracting the weight of the input
components from the wet weight of the output components.
• The estimations for the produced nitrogen dioxide were made according to the chemical
equation of the silver dissolution with nitric acid.
• The deficiency of the mass in the flowchart was identified that it is most probably the
water, which had vaporised (especially during heating). This is proved plausible considering
that the evaporation enthalpy of water is 2257 kJ / kg, charcoal produces 25 MJ / kg and
assuming a 30 % efficiency factor. Following for 4,91 kg (4880 g + 30 g) water vapour
approximately 1,3 kg charcoal is used.
The quantified mass flows are shown in the subsequent flowcharts.
81 E-waste recycling in India
Input material 1
Energy (coal) L 1: Lixiviation water vapour
Hot water
Substance 1
Water L 2: Sieving/Washing body components water vapour
From “silver-salt- silver-salt S 1 : Gold formationPreparation” aluminum foils Water Cloth S 2: decantation/ waste solution Filtering
Energy (coal) Lime P 1: Melting Substance 2 Substance 3 P 2: Pouring Process flux
Water P 3: Grinding silver solution 2 Ag- Recovery Solid(gold) Pieces P 4: Boiling Water vapour
Water P 5: Partition silver solution 2 Ag- Recovery Nitric acid nitrogen dioxide
Substance 3 P 6: Melting organic waste
82 E-waste recycling in India
Gold
Fig-40 Quantified flowchart of the cyanide leaching (main process); unit of numbers is gram.Chapter 2 Gold recovery techniques and hazards
Energy (coal) Silver PS 1: Heating Nitrogen dioxide Nitric acid Silver
Water
Sodium chloride PS 2: Precipitation Water
Hot water PS 3: Decantation
Water PS 4: Mixing Silver-salt
Unknown salt silver solution 1 Ag-recovery
Caustic soda
Fig-41 Preparation of silver-salt used in the main process of the cyanide leaching; unit ofnumbers is gram.
The following tables (Table 6and Table 7) give an overview of all the in- and outputs and are
quantified according to the functional unit (“one gram recovered gold”). In addition, the further
destinations of the outputs are noted.
Table 6: Input materials of the cyanide leaching per gram recovered gold
Input g / g gold
Input material 2,07E+04
Water 5,36E+04
Substance 1 (containing cyanide) 1,85E+02
Aluminium 4,67E+01
Nitric acid 6,77E+02
Lime 4,67E+01
Silver 1,17E+02
83 E-waste recycling in India
Sodium chloride 3,93E+02
Caustic soda 2,45E+02
Unknown salt 1,35E+02
Unknown substances (2, 3) 2,00E+01
Table 7: Output materials of the cyanide leaching per gram recovered gold
Output g / g gold Destination
Body components 2,07E+04 Solid waste stream
Water vapour 8,41E+03 Air
Waste solution 3,02E+04 Drain
Silver solutions 1,68E+04 Recovery
Fumes (Nitrogen dioxide) 8,00E+01 Air
Silver 6,67E+00 Process cycle
Gold 1,00E+00 Sale
The silver solutions are further treated with a silver recovery technique. This technique is not
included in the system boundary. However, a short description of the process is given in the
subsequent paragraph.
Silver Recovery
The silver from the silver solutions (output) is recovered using sodium chloride, which reacts with
silver producing silver chloride. In a further step iron is added which precipitates the silver, acting as
a reducing agent. The precipitation is then melted and solid silver is recovered. Using this procedure
in the above process 50 grams of silver, were recovered. Thus per gram of produced gold 83 grams
of silver are recovered. This means that during the cyanide leaching 27 grams of silver are lost per
gram recovered gold.
Mercury amalgamation at Eco BIRD
This technique was investigated during a visit of the informal facility doing usual business. The in-
and outputs were only partly measured. The input material of the observed process was connectors
assumingly from PWBs of telephones. From 14,3 kilograms of connectors 54 grams of gold was
84 E-waste recycling in India
recovered. During this technique, more than 130 g of mercury was used. The other used materials
have not been measured. The in- and outputs and their further destinations are listed below.
Table 8: Input materials of the mercury amalgamation per gram recovered gold
Input g / g goldInput material (connectors) 2,64E+02Mercury 3,59E+00
Sodium bicarbonateWater
Table 9: Output materials of the mercury amalgamation per gram recovered gold
Output g / g gold DestinationBody components Solid waste streamGas / Fumes (i.e. water vapour, nitrogen dioxide) AirCopper solution RecoveryWaste solution DrainMercury solution RecoveryMercury 0,07E+00 Process cycleGold 1,00E+00 Sale
Gold stripping at Surface Chem Finishers
The measurements for the different in- and outputs are made according to following descriptions:
• All the inputs of this process were measured except the water used for the purification.
• The wet output components were weighed. The estimation was made that the weight of the
dry output components correspond approximately with the weight of the input components
(the amount of leached metals was neglected).
• The amount of the vapour results from subtracting the weight of the input components
from the wet weight of the output components.
• The waste solution 1 was measured using a measuring cup.
• The waste solution 2 was not measured.
The processes and the quantified in- and outputs of gold stripping, showing the mass flow as it was
determined during the on site observation. A flowchart illustrating the different process steps
85 E-waste recycling in India
Connectors
Gold stripper Leaching vapour
Water body components
aqua regia separation waste solution
water
ferrous purification waste sulphate solution water gold
Fig-42 Simplified and quantified flowchart of the “gold stripping”; unit of numbers is gram.
The following tables (Table 10 and Table 11) give an overview of all the in- and outputs of the
process and their further destinations are noted.
Table 10: Input materials of the “gold stripping” per gram recovered gold
Input (g) Per g goldInput material 6,48E+03Water >2,75E+04Gold Stripper 1,23E+03Hydrochloric acid 5,93E+02Nitric acid 2,16E+02Ferrous sulphate 4,07E+02
Table 11: Output materials of the “gold stripping” per gram recovered gold
Output (g) Per g gold DestinationBody components 6,48E+03 Solid waste streamVapour 3,09E+02 Air
86 E-waste recycling in India
Waste solution 1 1,48E+04 Treatment plantWaste solution 2 >1,48E+04 Treatment plantGold 1,00E+00 Gold plating
Interpretation
Based on the system descriptions and quantifications the critical outputs, concerning the
environment and human health, of the three gold recovery processes were identified. These
hazard-“hot spots” are listed and described for each process. From some of these critical outputs
samples were taken and tested for a range of metals that are known to have a high potential to bio-
accumulate in the environment. Additional on site observations during the conducted processes are
qualitatively discussed.
Cyanide leaching at Eco BIRD
Major hazard-“hot spots”
1. Fumes: The most obvious contamination during the observation was the nitrogen dioxide, a red-
brown fume that was generated during the dissolution of silver, which irritated the eyes and
provoked dizziness. The corresponding chemical equation is:
Ag + 2 HNO3 -> AgNO3 + NO2 ↑+ H2O.
2. Waste solution: The waste solution is poured untreated into the drain. Since there is no
canalisation system, which ends up in a wastewater treatment plant the waste solution ends up
directly into the environment (water, soil and air) and can pollute the adjacent communities and
waters.
3. Body components: The body components probably end up in the solid waste stream. This means
that they are piled up on the streets for some time and in the best-case end up in the landfill. In both
cases over a certain amount of time, the contents in the body components will be released to the
environment. A study from Jang and Townsend (2003) showed that lead will leach out from PWB
when landfilled. Samples of the waste solution and the body components were collected and tested
for the concentration of a range of metals. The most relevant metals to the environment according to
Smidt (2006) and their concentration in the body components, respectively in the waste solution are
presented in Table 13 and Table 12. In addition, aluminium is also listed in Table 2.7 because of its
elevated concentration in the wastewater.
87 E-waste recycling in India
Table 12: Metal concentrations in the waste solution of the “cyanide leaching”
Element Concentration (ppm) Stdev [ppm]Aluminium (Al) 1315 55
Arsenic (As) <0.5Cadmium (Cd) <1
Copper (Cu) 185 6Mercury (Hg) <0.5
Nickel (Ni) 9Lead (Pb) 4Zinc (Zn) 17 1
Table 13: Metal concentration in the body components of the “cyanide leaching”
Element Concentration (ppm) Stdev (ppm)Copper (Cu) 229250 2333Nickel (Ni) 3200 141Lead (Pb) 22650 1626Tin (Sb) 5100 283Zinc (Zn) 23950 4596
Additional on site observations
The handling of the materials, which contain cyanide salts and nitric acid, is very frivolous and no
personal protection like gloves, goggles or masks are used. All of the workers have small burns in
the skin of the palms and a yellowish discoloration of skin and nails which are most probably
symptoms of the contact with nitric acid. Beverages and food are consumed while handling the
different and often hazardous substances. Thus, the substances can enter the body through absorption
or ingestion.
Comparison to the Swiss legislation
To give a quantitative statement to the possible hazards the results of the sampling are put into
relation with the allowed concentrations to discharge industry effluents into water in Switzerland,
according to Annex 3, GschV (Schweizerische Eidgenossenschaft, 1998). The Swiss “regulation of
water pollution control” limits the effluent concentration from industry, amongst others, of the pH,
eight metals and the free cyanide ion. These metals (plus mercury, molybdenum and thallium) are
88 E-waste recycling in India
the most relevant heavy metals to the environment. In the following table, the requirements of the
Swiss regulation are compared with the concentration of the wastewater of the “cyanide leaching” at
Eco BIRD. The ratio indicates the deviation of the values of the waste effluent from the cyanide
leaching conducted at Eco BIRD, in Bangalore, to the Swiss thresholds.
Table 14: Comparing the thresholds of the Swiss legislation of industrial
waste water with the found concentration in the waste solution of the “cyanide leaching”
Parameter Request GschV Ratio Waste water Eco BIRDpH-value 6.5 to 9.0 12
Arsenic (As) 0.1 mg / l < 5 <0.5 mg / lLead (Pb) 0.5 mg / l 8 4 mg / l
Cadmium (Cd) 0.1 mg / l < 10 <1 mg / lChromium (Cr) 2 mg / l n.a.
Cobalt (Co) 0.5 mg / l n.a.Copper (Cu) 0.5 mg / l 370 185 mg / lNickel (Ni) 2 mg / l 4.5 9 mg / lZinc (Zn) 2 mg / l 8.5 17 mg / l
The concentration of copper in Eco BIRD’s effluent exceeds Swiss industrial wastewater thresholds
370 times. In addition, the concentrations of all the other heavy metals are above the Swiss
thresholds. These high concentrations of metals in the effluent are because the cyanide salt, which is
used to dissolve the gold, also dissolves all other metals. Another concern is the high pH of the
tested effluent, which makes the water environmentally hazardous.
Mercury amalgamation at Eco BIRD
Major hazard-“hot spots”
1. Fumes: The most obvious exposure to a hazard has been observed during the first step in the
mercury amalgamation process when almost the whole workplace had been covered with a redish
fume. Nitrogen dioxide is produced, corresponding to the chemical equation:
2 NO3- + 4 H+ + Cu -> 2 NO2 + H2O + Cu++.
It was observed that the mercury is heated and vaporises during the purification. Thus, it ends up in
the air. The production of gold using mercury amalgamation is stated tobe an important source of
anthropogenic releases of mercury (UNEP, 2002). It is known that during this process extensive
amounts of mercury end up in the atmosphere and biosphere. For example: The mean value of
89 E-waste recycling in India
mercury loss in mines of the Madeira Rivers, Brazil is 1,32 kg mercury per 1 kg gold (Stüben, 2004).
In the Mindao Region, Philippines there is a mean value of mercury loss of 5 kg Hg/kg Au. The
exposition to mercury during gold recovery in the Philippines has been studied by Maydl (2004).
The practice is discouraged, because “…poor management of both liquid mercury and the vapour
arising from volatilising mercury contributes to serious health problems…” (Logsdon et al., 1999).
2. Waste solution: It is known that from the waste solution copper is recovered in a further process.
Therefore, the copper concentration is probably lower than it is measured in the waste solution of the
“cyanide leaching”. However, after the copper recovery the solution is also poured into the drain. An
important difference between this solution and the before described solution is the acidity. Using
such a high amount of nitric acid will lead to a low pH. The acidification of the water and sediments
make toxic metals more mobile and therefore more likely to have toxic effects on aquatic life
(Brigden et al., 2005).
3. Body components: The body components of the “mercury amalgamation” are sometimes again
processed with the “cyanide leaching”. Afterwards they are also dumped in the streets and the metals
that are still contained in the components will leach out sooner or later.
Additional on site observations
See additional on site information for cyanide leaching in the above subchapter.
Gold stripping at Surface Chem Finishers
Major hazard-“hot spots”
1. Waste solution: The waste solution is given to an effluent treatment plant (PAI & PAI Chemicals
(India) Pvt. Ltd.), thus it will be treated and the hazardous substances within should be eliminated.
2. Body components: The body components also land in the solid waste stream. As mentioned
before several (heavy) metals are still present within the remaining components and leach out
eventually. A sample from the body components could be taken and was tested for the concentration
of a range of metals.
90 E-waste recycling in India
Table 15: Metal concentration in the body components of the “gold stripping”
Element Concentration (ppm)Copper (Cu) 223000Nickel (Ni) 5000Lead (Pb) 2000Tin (Sb) 11000Zinc (Zn) 33000
Additional on site observations
During the on site observations no obvious hazards could be observed. The handling of the
substances has been very careful and both an exhaust system and personal protection equipment has
been used.
Discussion
Suitability of the method
The method is based on the scientific concept of the mass flow analysis and was adjusted according
to the encountered situations and the available resources. It has been a suitable tool to make a
quantitative evaluation of the processes. The method helps increase the knowledge of the conducted
processes and the gained data are transparent and objective. “One of the major problems in using this
method (MFA) in regions in developing countries is the availability of reliable data” (Binder et al.,
2001). Addressing this problem experimental data is collected in addition to literature research and
interviews. Within the time limits of this thesis and having a certain amount of provided material,
only two of the three encountered gold recovery techniques could be fully quantified. Furthermore, a
repetition and improvement of the measurements was not possible. Thus, it is a momentary
recording of the process using the provided material. This leads to the fact that statistical procedures
cannot be applied to give the data more weight. Nevertheless, it was possible to describe all
investigated gold recovery processes qualitatively in detail and to quantify two of the processes.
Evaluation of the systems
In the following subchapters, an overview of the conducted techniques is presented. Further it is
discussed whether the characterisation of the different techniques presented in this thesis can be
regarded as representative in general for these techniques in Bangalore. This is a very important
issue as the investigation is based only on a few measurements. Consequently, this might not be
91 E-waste recycling in India
sufficient to use the data for the definition of standard processes. Despite of the restrictions in
sampling and measuring the identification of the ‘hot spots’ was possible.
INPUT MATERIAL
Water
Cyanide Fumes (NO2)
Nitric acid
Aluminum Cyanide leaching Waste solution environment
Silver
Other Body components
Substances
Gold
Fig-43 Major flows of the “cyanide leaching”.
Discussion
In the investigated experimental technique the same processes, containers, etc. are used as in a usual
cyanide leaching technique. The quantity of the provided input material was below the usual
quantity. Nevertheless, the investigation gives adequate indications of the used amount of materials
in a usual technique conducted in this facility. To recover one gram of gold in the investigated
technique approximately 200 grams of a substance containing cyanide was used. In another observed
cyanide leaching technique, conducted at the same unit doing usual business, they used 10 grams of
the cyanide containing substance to recover one gram of gold. With the chemical equation
4 Au(s) + 8 CN-(aq) + O2(g) + 2 H2O(l) 4 Au(CN)2-(aq) + 4 OH-(aq),
it can be calculated that approximately 0,66 g of potassium cyanide, respectively 0,5 g of sodium
cyanide would be needed to leach out one g of gold. Explanations of the much higher amount of
cyanide used in the processes could be:
92 E-waste recycling in India
• The concentration of cyanide salt in the substance is low.
• The input material contains many other metals, which leads to a high cyanide use.
Gold has a high standard reduction potential and is therefore the last metal to be dissolved.
Thus, to calculate the exact needed amount of cyanide the exact composition of the input material
would have to be known. Hence, the amount of needed cyanide increases with each present metal.
This could explain the conducted segregation for apparent gold before the material enters the gold
leaching process.
It also leads to the assumption that rather more cyanide is used as required to make sure all the gold
is dissolved. In the investigated process, 21 kg of input material to recover one gram of recovered
gold is needed. In another observed process, 3 kg of input material per one gram of recovered gold is
used and from the estimated figures, the average recovery rate would be one g gold per 250 g of
input material. This wide-ranging amount of input material used to recover one gram of gold might
be because of the different gold content in the input material and because of different people
conducting the process. A piece in the process, which is surprising, is the preparation of silver-salt
(see PS 1 – PS 3). Theoretically, silver-salt is not needed to precipitate/form the gold (see S 1 (ETH)
and literature resources, gold can be precipitated using only zinc or aluminium. Due to the addition
of silver-salt 27 grams of silver are lost per gram recovered gold, which is a lot considering that it is
a precious metal and thus valuable.
Possible explanations could be:
• In the first process, excess cyanide is added to be sure all possible gold is dissolved.
The silver salt is used to bind the excess cyanide in the “Gold formation” process step
(S 1). Maybe it is cheaper to add the silver that can be recovered and used again than
to add more aluminium or zinc to precipitate the gold (Schönberg, 2006)
• The used silver is not pure enough to be sold and is therefore a waste product that
has no better use than to decrease the amount of aluminium needed in the separation
process.
• “The purpose of adding silver is to obtain a more impure gold alloy. If there is more
silver than gold present in the alloy, it is easier to separate them” (Parthasarathy,
2006).
93 E-waste recycling in India
Regarding the purification process (see P 1 to P 6), the question is raised why it is composed of so
many steps. The essential steps are the melting (P 6) and the partition (P 5), where the gold is
separated from silver and other impurities. Theoretically, the process could be simplified
concentrating on the essential steps. However, the experience of the workers goes back several
generations and the made assumptions would have to be discussed with them and evaluated.
Mercury amalgamation at Eco BIRD
Overview
Input material
Water Fumes (NO2, mercury vapour)
Mercury mercury waste Environment amalgamation solution
Sodium Body bicarbonate components
Gold Fig-44 Major flows of the “mercury amalgamation”.
Discussion
During the mercury amalgamation in the worst case 3,5 grams of mercury is lost per gram recovered
gold. This is a very dangerous loss to health and environment. Some of this mercury is recovered in
a subsequent mercury recovery technique, which has not been further investigated. However, the
loss due to vaporisation could be easily decreased by collecting and condensing the mercury vapour
as it is done in several gold mines using this process.
94 E-waste recycling in India
Gold stripping at Surface Chem Finishers
Overview
Input material
Water Waste Gold solutionStripper cyanide
Leaching environmentAqua regia BodyFerrous componentssulphate Gold
Fig-45 Major flows of the “gold stripping”.
Discussion
The conducted experimental technique was a miniaturised example of the usual technique. Usually
around 100 kg of input material is treated together. Because of the small amount of material, some
adaptations had to be made: no additional oxygen was pumped into the solution, which is left over
night; the cathode was titanium instead of stainless steel; the cathode was put directly into aqua regia
(usually the gold is scraped off before). According to the director of the facility, the experiment is
nevertheless comparable with his usual technique.
Taking the figures given from the Engineer of E-Parisaraa 2 kg input material are needed to recover
one g gold. In the experiment 6,5 kg of input material would be needed to recover one gram gold.
This is an indication that the input material of the experiment is a little less concentrated on gold or
the gold is easier to leach out when the quantity of used material and substance is higher. In order to
take the right amount and not waste anything the different auxiliary substances are always measured
carefully. Thus, it seems that this process is standardised and it is known that qualitative checks are
regularly executed by the director of the facility.
95 E-waste recycling in India
Monitors
Monitors are much sought after by scrap dealers as they contain good quantity of copper yoke,
besides circuit board and picture tube. The different recovery processes observed in MMR are given
below. Dissembling of CRT and Extraction of Components The first step in monitor recycling
involves physical removal of plastic casing, picture tube (cathode ray tube), copper yoke and plates.
The intact and functional CRT is used for the manufacture of colour and black & white televisions
for local brands. Re-gunning is possible only for those monitors whose terminal pin (diode pin) of
electron gun has not broken in the process of removing yoke from gun.
Recovery of Glass from CRT
Defective CRT is broken down to recover iron frames from the glass funnel as shown in Figure
46,47. The iron frames are found only in color CRTs and not in black & white monitors. The glasses
and iron frames from picture tubes are given to waste traders. Yoke Core,
Yoke Core, Metallic Core and Copper from Transformers
The copper and yoke core recovered from yoke coils found around the picture tube end is sold to
copper smelters and re-winders as shown in Figure 48 and Figure49. Apart from the yoke, copper
and metallic core is also recovered from transformers mounted on the circuit board of the computer.
The circuit tray also contains a number of condensers of different sizes. Depending upon their
condition and demand they again enter into the secondary market for reuse. If they are defective,
they are sold along with the motherboard. Rare Earth Core of Transformer and Copper These small
transistors and rare earth transformers are boiled in water with small amount of caustic soda, which
results in loosing of joint between the core resulting in core and copper extraction as shown in
Figure 11.
Copper Extraction from Wires
Two kinds of processes are being followed under this category as listed below:
1. Manual drawing of wires for copper
2. Extraction of copper by burning the wire
96 E-waste recycling in India
Plastic casing of ether ABS or high Separated for sale
Opening the plastic case CRT with PWB and other casing
CRT of breakage separation of PWB York and CRT
York for core and copper extraction separated PWB
Fig-46 Dissembling of CRT and Extraction of Components
97 E-waste recycling in India
Fig-47.a Glass Recovery by CRT Breaking
York with component
York core cutting of copper form core is shown
Copper
Fig-47.b Extraction of Yoke Core and Copper
98 E-waste recycling in India
Metallic transformer cutting of cooper with nail and hammer
Metallic core copper
Fig-48 Extraction of Metallic Core of Transformer and Copper
Rear earth transformer boiling of transformer rear earth core
Copper
Fig-49 Extraction of Rare Earth Core of Transformer and Copper
Manual drawing of Wires for Copper
Under this process with the use of knife the edge of wire is cut and then with the help of pliers the
copper is extracted from PVC as shown in Figure 50. The process is as shown below copper goes for
sale to copper smelters and PVC is used for plastic graining.
99 E-waste recycling in India
copper
Computer wire cutting the wire edge and pull the copper
PVC
Fig-50 Computer Cable
Plastic Shredding and Graining
The plastic casings of monitors are made either of PVC (polyvinyl chloride) or ABS (acrylonitrile-
butadiene styrene). PVC was used more commonly in the early models of computers. Now
computer-manufacturing companies have shifted to ABS plastic in the production of monitors.
Though both types of plastics are currently being recycled as shown in Figure 51, the PVC one
cannot be recycled. This is due to the high percentage of silicate being added for making it fire
retardant. The silicate plastic often ends up at kilns as an alternate source of energy. The plastic
casing is recycled into EBS or High Impact Plastic. These kinds of plastics are frequently used in
manufacturing toys.
Dismantling of compressor & segregation of compressor & cooling box
Refrigerator is dismantled for metal recovery, plastic recovery, insulating material
and compressor as shown in Figure 51.
100 E-waste recycling in India
In 02: manual labor Ou 01: separated cooling box
In 01 end life of refrigerator P 01: manual breaking using hammer and punches
Ou 02: segregation of insulating material
Ou 03: separated compressor
Fig-51 Dismantling of Refrigerator and Segregation of Compressor and
Cooling Box
Disposal
It has been observed in many parts of the world that the most common practice of disposing e-waste
is simply throwing it away with domestic waste, which eventually ends up in landfills or gets
incinerated. However, this may result in several environmental hazards and hence, the waste must be
disposed off in a proper manner.
Fig-52 Plastic Shredding
Advantages of Recycling e-waste:
101 E-waste recycling in India
· It will give way to Perfect Management of E-Waste.
· As there will be virtually no landfilling or incineration, the hazards to the environment will be
avoided.
· Waste disposal costs will be reduced for organizations handling their own EWaste.
· It will generate good quantity of raw materials for various other industries. Moreover, the cost of
this raw material will be much less than that obtained from its original source.
· Widely used metals like copper, platinum have to be dug out from their ores. Acquiring them this
way will not only be a cheaper, less time consuming mean, but will also result in reduction of waste,
and its hazards by reuse.
· Plastics can be reused relatively many times. So recycling them from E-Waste makes use of this
advantage of plastics.
· It will have better and safer working conditions relative to backyard stripping corporations. This
means protected means of dismantling and recycling of EWaste.
· It will generate many employment opportunities for people from many disciplines.
13. Responsibilities of government, industries, and citizen.
102 E-waste recycling in India
Considering the severity of the problem, it is imperative that certain management options be adopted
to handle the bulk e-wastes. Following are some of the management options suggested for the
government, industries and the public.
Responsibilities of the Government
(i) Governments should set up regulatory agencies in each district, which are vested with the
responsibility of co-coordinating and consolidating the regulatory functions of the various
government authorities regarding hazardous substances.
(ii) Governments should be responsible for providing an adequate system of laws, controls and
administrative procedures for hazardous waste management (Third World Network. 1991). Existing
laws concerning e-waste disposal be reviewed and revamped. A comprehensive law that provides e-
waste regulation and management and proper disposal of hazardous wastes is required. Such a law
should empower the agency to control, supervise and regulate the relevant activities of government
departments.
Under this law, the agency concerned should
Collect basic information on the materials from manufacturers, processors and importers
and to maintain an inventory of these materials. The information should include toxicity
and potential harmful effects.
Identify potentially harmful substances and require the industry to test them for adverse
health and environmental effects.
Control risks from manufacture, processing, distribution, use and disposal of electronic
wastes.
Encourage beneficial reuse of "e-waste" and encouraging business activities that use
waste". Set up programs so as to promote recycling among citizens and businesses.
Educate e-waste generators on reuse/recycling options
103 E-waste recycling in India
(iii) Governments must encourage research into the development and standard of hazardous waste
management, environmental monitoring and the regulation of hazardous waste-disposal.
(iv) Governments should enforce strict regulations against dumping e-waste in the country by
outsiders. Where the laws are flouted, stringent penalties must be imposed. In particular, custodial
sentences should be preferred to paltry fines, which these outsiders / foreign nationals can pay.
(v) Governments should enforce strict regulations and heavy fines levied on industries, which do not
practice waste prevention and recovery in the production facilities.
(vi) Polluter pays principle and extended producer responsibility should be adopted.
(vii) Governments should encourage and support NGOs and other organizations to involve actively
in solving the nation's e-waste problems.
(viii) Uncontrolled dumping is an unsatisfactory method for disposal of hazardous waste and should
be phased out.
(viii) Governments should explore opportunities to partner with manufacturers and retailers to
provide recycling services.
Responsibility and Role of industries
1. Generators of wastes should take responsibility to determine the output characteristics of
wastes and if hazardous, should provide management options.
2. All personnel involved in handling e-waste in industries including those at the policy,
management, control and operational levels, should be properly qualified and trained.
Companies can adopt their own policies while handling
e-wastes. Some are given below:
Use label materials to assist in recycling (particularly plastics).
Standardize components for easy disassembly.
104 E-waste recycling in India
Re-evaluate 'cheap products' use, make product cycle 'cheap' and so that it
has no inherent value that would encourage a recycling infrastructure.
Create computer components and peripherals of biodegradable materials.
Utilize technology sharing particularly for manufacturing and de
manufacturing.
Encourage / promote / require green procurement for corporate buyers.
Look at green packaging options.
3. Companies can and should adopt waste minimization techniques, which will make a
significant reduction in the quantity of e-waste generated and thereby lessening the impact on
the environment. It is a "reverse production" system that designs infrastructure to recover and
reuse every material contained within e-wastes metals such as lead, copper, aluminum and
gold, and various plastics, glass and wire. Such a "closed loop" manufacturing and recovery
system offers a win-win situation for everyone, less of the Earth will be mined for raw
materials, and groundwater will be protected, researchers explain.
4. Manufacturers, distributors, and retailers should undertake the responsibility of
recycling/disposal of their own products.
5. Manufacturers of computer monitors, television sets and other electronic devices
containing hazardous materials must be responsible for educating consumers and the general
public regarding the potential threat to public health and the environment posed by their
products. At minimum, all computer monitors, television sets and other electronic devices
containing hazardous materials must be clearly labeled to identify environmental hazards and
proper materials management.
Responsibilities of the Citizen
Waste prevention is perhaps more preferred to any other waste management option including
recycling. Donating electronics for reuse extends the lives of valuable products and keeps them out
of the waste management system for a longer time. But care should be taken while donating such
items i.e. the items should be in working condition.
105 E-waste recycling in India
Reuse, in addition to being an environmentally preferable alternative, also benefits society. By
donating used electronics, schools, non-profit organizations, and lower-income families can afford to
use equipment that they otherwise could not afford.
E-wastes should never be disposed with garbage and other household wastes. This should be
segregated at the site and sold or donated to various organizations.
While buying electronic products opt for those that:
o are made with fewer toxic constituents
o use recycled content
o are energy efficient
o are designed for easy upgrading or disassembly
o utilize minimal packaging
o offer leasing or take back options
o have been certified by regulatory authorities. Customers should
opt for upgrading their computers or other electronic items to the
latest versions rather than buying new equipments.
NGOs should adopt a participatory approach in management of e-wastes.
106 E-waste recycling in India
14. E-Waste Policy for India
Under the aegis of ASSOCHAM Expert Committee on Environment a Seminar on “E-Waste Policy
for India” was held in New Delhi on May 26, 2006. Designed with the aim of spreading awareness
on the hazards of E-waste in the country, discussing E-waste management & disposal options and
inviting inputs for framing an E-Waste policy for the country, this well-attended Seminar had
discussants representing industry, research and development institutions, environmental
organizations and consultants, legal practitioners, and E-waste recyclers.
The Keynote Speaker in the Seminar was Dr. R.S. Mahawar, Additional Director Central Pollution
Control Board.
Eminent speakers, such as Mr. P. Ravindranath, Director, Government and Public Affairs, Hewlett-
Packard India,
Mr. Amit Jain, Management Director – India Operations, IRG SSA,
Dr. T.K. Joshi, Director, Centre for Occupational and Environmental Health, Government of NCT of
Delhi,
Mr. Gaurang Baxi, Manager, Corporate HSE, Kodak India,
Mr. Rahul Sharma, Director, TRI International Limited,
Dr. S.K. Pachauri, Former Director General, National Productivity Council and Ex-Secretary to the
Government of India,
Mr. M.S. Nagar, Ex CMD, Indian Rare Earths Ltd. and former Consultant, Ministry of Environment
and Forests, Government of India,
Dr. Usha Dar, President, Council of Industrial Environmental Relations in Delhi, shared their views
and experiences in this Seminar.
In the backdrop of resurgent growth of the Indian economy and greater reliance on electronic
hardware for household, industrial and office automation, commitment to eco-responsibility was
seen as a sine qua non for the society, economy and the environment.
There was unanimity that electronic waste containing substances like lead, cadmium, mercury,
polyvinyl chloride (PVC) has immense potential to cause enormous harm to human health and
107 E-waste recycling in India
environment, if not disposed properly since the extant prescriptions for its disposal and safeguard
were inadequate. Thus, the imperative need for early formulation of a holistic E-waste legislation
which will eventually lead to enabling policy. It was consensually agreed that such a policy must
appropriately reflect the concerns of various stakeholders besides views of practitioners in the field,
both in the organized and the unorganized sector.
The deliberations in the Seminar highlighted the likely enormity in the magnitude of E-waste to be
generated every year (approx 1,50,000 tonnes). Issues relating to poor sensitisation about this sector,
low organized recycling, cross-border flow of waste equipment into India, limited reach out and
awareness regarding disposal, after determining end of useful life, and lack of coordination between
various authorities responsible for E-waste management and disposal including the non-involvement
of municipalities in E-waste management were discussed threadbare. The emerging global trend of
producer responsibility for disposal after useful life becoming the governing principle globally by
the year 2008 and lack of steps in India in this regard were cited prominently during the
deliberations.
Conscious of the prevalent uncertainties regarding “when, where, and how” to dispose hazardous,
harmful E-waste, the role of informal sector in the process and the necessity of introducing a
comprehensive framework early, ASSOCHAM affirms its commitment to assist the Government in
carving out an inclusive E-waste management policy, as for meeting the need for finding an “India
Unique Solution”, that strikes a visionary balance between precepts and praxis for sustainable
management of E-waste, such a policy alone can bring the desired paradigm shift.
ASSOCHAM, in recognition of this urgent necessity of proper management of E-waste in the
country therefore recommends for consideration of the Government the following :
1. Promulgate an all-embracing national E-waste Management law, and an all-encompassing
policy thereunder, for substituting the existing Hazardous Waste (Management and Handling)
Rules 2003, as the latter are not comprehensive enough to attain the aforesaid objectives.
108 E-waste recycling in India
2. Initiate the process for complete national level assessment, covering all the cities and all the
sectors. Such base line study must envelope inventories, existing technical and policy
measures required for emergence of national E-waste policy/strategy and action plan for eco-
friendly, economic E-waste management. The study should also culminate in identifying
potentially harmful substances and testing them for adverse health and environmental effects
for suggesting precautionary measures.
3. Create a public-private participatory forum of decision making, problem resolution in E-
waste management. This could be a Working Group comprising Regulatory Agencies,
NGOs, Industry Associations, experts etc. to keep pace with the temporal and spatial changes
in structure and content of E-waste. This Working Group can be the feedback providing
mechanism to the National Nodal Authority in the Government that will periodically review
the existing rules, plans and strategies for E-waste management.
4. ASSOCHAM as a Knowledge Chamber advocates creation of knowledge data base on end
of useful life determination, anticipating the risks, ways of preventing and protecting from
likely damage and safe and timely disposal of E-waste. It accordingly urges the Government
to promote Information, Education and Communication (IEC) activities in schools, colleges,
industry etc. to enhance the knowledge base on E-waste management using the PPP mode.
5. Creation of data base on best global practices and failure analyses for development and
deployment of efficacious E-waste management and disposal practices within the country.
6. Device ways and means to encourage beneficial reuse/recycling of E-waste, catalyzing
business activities that use E-waste.
7. Formulate and regulate occupational health safety norms for the E-waste recycling, now
mainly confined to the informal sector.
8. Review the trade policy and exim classification codes to plug the loopholes often being
misused for cross-border dumping of E-waste into India.
109 E-waste recycling in India
9. Insist on stringent enforcement against wanton infringement of Basel convention and E-waste
dumping by preferring incarceration over monetary penalties for demonstrating deterrent
impact.
10. Foster partnership with manufacturers and retailers for recycling services by creating an
enabling environment so as dispose E-waste scientifically at economic costs.
11. Mandate sustained capacity building for industrial E-waste handling for policy makers,
managers, controllers and operators. Enhance consumer awareness regarding the potential
threat to public health and environment by electronic products, if not disposed properly.
12. Enforce labeling of all computer monitors, television sets and other household/industrial
electronic devices for declaration of hazardous material contents with a view to identifying
environmental hazards and ensuring proper material management and E-waste disposal.
13. Announce incentives for growth of E-waste disposal agencies so that remediation of
environmental damage, threats of irreversible loss and lack of scientific knowledge do not
anymore pose hazards to human health and environment. Simultaneously, as a proactive
step, municipal bodies must be involved in the disposal of e-waste lest it becomes too late for
their intervention, should large handling volumes necessitate it.
14. Consider gradual introduction of enhanced producer responsibility into Indian process,
practices and procedures so that preventive accountability gains preponderance over polluter
immunity.
110 E-waste recycling in India
15. CONCLUSION
The requirement and usage of electronic equipments is increasing day by day, as new, cheaper and
better technologies replace the old ones. This renders the old equipments useless, and leaving huge
amounts of electronic waste behind. However, this waste still has valuable metals and substances
that can be used. Consequently, the dismantling and reuse of E-waste components has become quite
a lucrative industry. But a only a fraction of the total amount of E-Waste is found to be recycled, and
the rest discarded along with domestic waste. By discarding the rest of the waste, not only is the
environment being contaminated with hazardous substances, but also many reusable valuable
materials get are wasted.
The materials recovered from E-Waste are often in richer quantity than their original sources. In
addition to that, their recovery is much cheaper as well. Hence E-Waste can be considered to be a
rich yet cheap source of many valuable substances like plastics, gold, copper etc. This implies that
with better collection and processing techniques, an E-Waste recycling industry, set up with
contributions from the government and the consumers, can generate remarkable revenue, at the same
time providing a sustainable E-Waste management technique
16. REFERENCES
111 E-waste recycling in India
HTTP://WWW.IIMM.ORG/NATIONAL_EXECUTIVE.HTM
HTTP://WWW.GOOGLE.CO.IN
HTTP://WWW.SCRIBD.COM
HTTP://WGBIS.CES.IISC.ERNET.IN/ENERGY/PAPER/RESEARCHPAPER.HTML
HTTP://EWASTEGUIDE.INFO/SYSTEM/FILES/KELLER_2006_ETH-EMPA.PDF
HTTP://WWW.NRCAN.GC.CA/MMS-SMM/BUSI-INDU/RAD-RAD/PDF/ELEC-SFR-ENG.PDF
112 E-waste recycling in India