Metalliferous minerals processing scoping project - MSA · Silver (Ag ... Refining Cast Transport...

Metalliferous minerals processing scoping project

Final report

September 2011

Contents Executive summary ..................................................................................... 1

Project summary ................................................................................................................... 1

Summary of processes vs metals ........................................................................................... 1

Summary of findings and recommendations ......................................................................... 1

Scope ........................................................................................................... 2

Methodology ............................................................................................... 2

Coverage issues ........................................................................................... 3

The metalliferous sector .............................................................................. 3

Overview ............................................................................................................................... 3

Processing ............................................................................................................................. 4

Discussion of results ................................................................................... 5

The PMA design philosophy ................................................................................................. 5

An analysis of the processes ................................................................................................. 6

Ancillary processes ............................................................................................................... 7

Off gases, wastes and by-products ........................................................................................ 7

Boundary issues with RII09 .................................................................................................. 8

Boundary issues with PMC10 ............................................................................................... 8

Unit operations in the processes ................................................................. 8

Size reduction ........................................................................................................................ 8

Particulate transport and storage ........................................................................................... 9

Pelletising and sintering ........................................................................................................ 9

Loading ............................................................................................................................... 10

Wet chemical dissolution .................................................................................................... 10

Separation ............................................................................................................................ 11

Clarification/thickening....................................................................................................... 12

Precipitation, complexing ................................................................................................... 12

High temperature processes ................................................................................................ 13

Electrolysis/electrochemical reactions ................................................................................ 14

Downstream processes ........................................................................................................ 15

Unit operations in ancillary processes ...................................................... 16

Current training and qualification approaches .......................................... 17

Recommendations and conclusions re units of competency .................... 17

Individual units ................................................................................................................... 18

Units related to unit operations ........................................................................................... 18

Summary of recommendations ........................................................................................... 22

Appendix 1 Persons contacted .................................................................. 24

Sites visited as part of the field research ............................................................................. 24

Sites contacted but where no visit occurred ........................................................................ 25

Appendix 2 Metalliferous processes and related units ............................. 26

Aluminium (Al) ................................................................................................................... 26

Copper (Cu) ......................................................................................................................... 28

Gold (Au) ............................................................................................................................ 30

Iron and Steel (Fe) ............................................................................................................... 31

Lead (Pb) ............................................................................................................................. 34

Magnesium (Mg)* ............................................................................................................... 35

Manganese (Mn) ................................................................................................................. 36

Nickel (Ni)* ........................................................................................................................ 37

Silicon (Si) .......................................................................................................................... 39

Silver (Ag)* ......................................................................................................................... 40

Tin (Sn)* ............................................................................................................................. 40

Titanium (Ti) ....................................................................................................................... 41

Uranium (U) ........................................................................................................................ 44

Zinc (Zn) ............................................................................................................................. 45

Total Training and Performance Solutions MSA/Metalliferous processing scoping

Final report page 1 September 2011

Executive summary

Project summary

This project is to report on the competency needs of the metalliferous

processing sector in Australia. The sector is defined as starting from the

extracted ore and ending with a processed product which includes metals and

marketed intermediates. The metals processed in Australia include:

■ aluminium

■ copper

■ gold

■ iron and steel

■ lead

■ magnesium

■ manganese

■ nickel

■ silicon

■ silver

■ tin

■ titanium

■ uranium and

■ zinc.

The processes have been described and the relevant units of competency (from

PMA08, PMC10, MEM05 and RII09) identified. There are some gaps in the

coverage and some alignments of units which could be improved. These issues

can be resolved by:

■ developing some new units of competency for PMA.

■ examining existing suites of PMA/PMC units and redrawing some of them to

give better alignment with the broader coverage of PMA

■ importing some additional units from RII09 and other Training Packages

Training currently undertaken is a mix of internal training and training aligned

to PMA08 or RII09. Much of it is aligned to RII09 as many of these companies

regard themselves as mineral companies rather than manufacturing.



Summary of processes vs metals

M

eta

l

Sizing Dissolution Separation Conversion Reduction Purification/

Refining Cast Transport Down-

stream Comminution Leaching Gravity Calcining Smelting Electrolysis Cast Truck Extrude

Sizing Digestion Flotation Smelting Furnace Furnace Train Mill

Sinter Elution Magnetic/Elec Roast Arc Chem Ship Coat

Ppt Filt

Ex

trac

tio

n –

RII

09

Al X X X X X X X X X X X X X

Cu X X X X X X X X X X

Au X X X X 1 X X X X X

Fe X X X X X X X X X X X X

Pb X X X X X X X X X X

Mg X X X X X X X

Mn X X X X X

Ni X X X X X X X X

Si X X X X X X

Ag X X X X X X X X X

Sn X X X X X X X X X X X

Ti X X X X X

U X X X X X X X X

Zn X X X X X X X X X X X X X X

1 Adsorbed onto activated carbon



Summary of findings and recommendations

The scope of PMA is intended to cover the metalliferous sector. However due to

historical factors this sector has never been given concentrated attention.

The PMA and PMC Training Packages between them have many units which

are relevant, but there are also obvious gaps in coverage while some existing

units are only an approximate fit for this sector.

RII09 has units covering most of this sector, however they would appear to have

a different design philosophy to PMA both with regard to the units and the

packaging into qualifications. So, while importing some RII09 units may be

appropriate, the importation of many units would cause distortions within PMA.

Many units considered are PMC units and in some unit operations there are both

PMA and PMC units which may possibly be relevant. The review of PMA to

include the metalliferous sector also presents an opportunity to review these

PMC units so creating one consistent suite of units within MSA. It is

recommended that this suite be PMA units that are then imported back into

PMC as required.

The units required for this section are explored in greater detail in the body of

this report. This is summarised as:

■ minor review of 4 PMA units

■ review 14 PMA/PMC units and create 17-20 new PMA units

■ validation of 2 PMC units for the metalliferous sector (assuming no review

required)

■ conduct analysis and develop 39-43 new units

■ import 7-9 units from relevant Training Packages

■ validate all units (with relevant PMA and PMC sectors)

■ import relevant new or modified PMA units back into PMC

■ make appropriate modifications to existing qualifications by inserting the

units into the relevant groups and validate the revised qualifications.



Scope

The defined scope for this project is:

1. Investigate what training and recognition processes are in place for the

metalliferous minerals processing sectors, including steel, light metals,

copper, nickel, gold and any other metals processed in Australia.

2. Analyse job roles, functions and scope of responsibility

3. Report on competency needs with detailed recommendations for

Training Package coverage.

Note that the proposed scope is defined as starting after the mineral/ore is mined

and would finish when a usable metal is available for use by the metal and

engineering or other sector. This report covers both ‘upstream’ or primary

processing and ‘down steam’ or secondary processing. Upstream is the wining

of the metal from the ore and typically finishes with the production of an ingot,

slab, billet or other large, but unformed piece of metal. Downstream typically

starts with this piece of metal and forms it by rolling or extruding. Note that as

die casting and foundry are already covered elsewhere, they do not form part of

this project or report. The agreed work included national face to face

consultations with the major metalliferous processing organisations.

The intention of this project is to make recommendations regarding additional

units and changes to existing units which will be required within PMA08

Chemical, Hydrocarbons and Refining Training Package (PMA08) to

thoroughly cover this sector. This work may also involve PMC10 Manufactured

Mineral Products units to a greater or lesser extent.

Methodology

This is basically a research project. The research has two basic components:

■ desk research

■ field research.

Desk research was undertaken to obtain an appreciation of the size and scope of

the sector in Australia and to identify key organisations within the sector. It also

provided preliminary information with regards to raw materials, process and

products produced.

Field research was conducted with a sample of sites to validate the desk

research and to explore for issues which may not emerge from the desk

research. The field visits were written up as a report which was then sent to the

relevant person at the site to allow for any corrections. This information has

been used in the construction of this report. It has been the intention of the field

research to visit at least one example of every metal processing plant. Those

where a visit has not been able to be organised have an * next to the title in

Appendix 2. Those who have been visited are listed in Appendix 1, along with a



list of organisations and people contacted where a visit was not possible.

Downstream processing has not had the same level of investigation and will

need greater initial investigation as part of the second phase of this project, the

development of relevant units and the modification of existing qualifications.

Processes for the metals were established and these were mapped to existing

units of competency. Gaps were therefore identified. Existing units of

competency were identified from both MSA and Skills DMC Training

Packages. The relationship between Skills DMC and MSA is explored as part of

this project.

Coverage issues

This project is being undertaken for Manufacturing Skills Australia (MSA)

which is one of 11 national Industry Skills Councils. MSA has coverage of

manufacturing and related industry.

Skills DMC (SDMC) is another one of the 11 national Industry Skills Councils

and has coverage of the resources and infrastructure industry.

MSA and SDMC have existing overlapping boundaries in the areas of:

■ quarrying (SDMC) and downstream processing such as cement and concrete

(MSA – PMC10)

■ drilling (SDMC) and downstream processing such as hydrocarbons

extraction, transmission and processing (MSA – PMA08)

■ concrete products (MSA – PMC10) and the downstream civil construction

(SDMC)

■ explosives manufacture2 (MSA PMA08) and the downstream use of

explosives in mining (SDMC)

■ metalliferous mining (SDMC) and the downstream processing (MSA

PMA08)

This last interface will be explored in more detail by this project.

The metalliferous sector

Overview

In broad terms the metalliferous processing sector starts after the mineral ore

has been mined (SDMC coverage) and includes everything up to and including

the production of a metal which is in a form suitable for use by the metal and

2 Explosives manufacturers will often value add to their physical product by also providing the service

of blasting so further making this existing boundary less than straight forward.



engineering, automotive or other sectors. It also includes the production of

metal compounds which are used in the making of other products.

Metals are often divided into a number of categories:

■ ferrous

■ non-ferrous

• base metals

• precious metals

• light metals3

Each of these in turn comprises a range of metals and/or metal alloys.

Metalliferous processing covers all of these metals, although little attention is

given to aluminium in this report as it is already covered within PMA08. Some

consultation was undertaken with alumina refining to ensure adequate coverage.

Minerals processing is closely associated with the resources sector in Australia

with much downstream processing being undertaken by the same businesses

which mine the ore, and sometimes on the same, or an adjacent site. Much of

mineral processing therefore is regionally disbursed. This is not always the case

with steel for example being traditionally (but not always) located close to the

source of coking coal rather than iron ore (in Australia) and aluminium,

manganese and silicon being located where there is cheap and reliable

electricity and an adequate port near a plant rather than with the relevant ore.

Processing

The boundary between mining and processing is rather permeable with size

reduction (crushing and grinding) and transport (conveying by various means)

occurring in both. Inevitably these comprise the last steps of mining and the first

steps of processing – getting solids of the size we can handle in the place we can

handle them.

Much of Australia’s minerals are not processed further than this but are

exported (typically in bulk by ship) in this raw form. Some however is further

transformed by a series of physical and chemical processes into a finished

metal, a metal compound or a processed mineral. Aluminium and titanium

provide examples of this.

Aluminium is mined as bauxite, processed (refined) to alumina and then further

processed (smelted) to aluminium. Bauxite, alumina and aluminium are all

exported with some alumina and aluminium being consumed domestically.

Titanium is mined as ilmenite (or other ore) and processed to titanium dioxide

(titanium metal does not seem to be made in Australia). Ilmenite/synthetic rutile

and titanium dioxide are all exported with a significant amount of titanium

3 Light metals (typically Mg, Al and Ti although sometimes also including other metals) are also base

metals.



dioxide being used domestically as a pigment (paint, ink, polymers and sun

screen).

An analysis of processing therefore needs to consider these stages and the

intermediate products as viable processes in their own right.

The major metals processed in Australia were determined by reference to

information from the Minerals Council of Australia and a document they

prepared in collaboration with Geoscience Australia. The details of these

processes are given in Appendix 2.

Discussion of results

The PMA design philosophy

General design philosophy

When PMA98 (the first PMA Training Package) was designed it was done so

on the basis that:

■ it was to provide a suite of technical qualifications

■ each technical qualification would therefore require competence in a

minimum number of technical units of competency

■ the technical units of competency would be based on what is known as ‘unit

operations4’ within this sector.

This basis has been maintained through into PMA08 and has been validated as

providing a robust design philosophy for training and qualification for this

industry.

A ‘unit operation’ is

■ ‘a basic step in a process’ (Wikipedia)

■ ‘any part of potentially multiple-step process which can be considered to

have a single function’ (Walker, Lewis and McAdams ‘The Principles of

Chemical Engineering’).

Any unit operation has and applies common techniques and principles. A total

process may be designed as a collection of appropriately sized and connected

unit operations.

The result of this is that to determine the relevant units of competency in

PMA08, the process needs to be examined and the unit operations of which it is

composed need to be determined.

4 Unit operations is also the basis of the study of chemical engineering or process engineering.



If the unit operations are known, so too are the units of competency. It is

necessary then to check that the unit of competency is applicable in that

particular context, and then appropriately contextualised in delivery.

Alignment of technical units to AQF

While strictly speaking units do not exist at a specific AQF level, units are

allocated to qualifications (which do have an AQF level) and to groups within a

qualification.

Units aligned as technical units for the Certificate II require competence in the

operation of an individual plant item.

Units aligned as technical units for the Certificate III require competence in the

operation of a plant unit which includes the operation of one or more plant items

which make up the unit as a whole. The Certificate II technical units do count

towards the Certificate III, but by themselves are not sufficient to qualify for the

award of the Certificate III.

Similarly with the Certificate IV, technical units should now be applied to an

entire plant area which may contain several plant units and/or many plant items.

Again the Certificate II and III units do count towards the certificate IV, but by

themselves are not sufficient to qualify for the Certificate IV.

The Diploma and Advanced Diploma are intended as paraprofessional

qualifications and so are not directly based on the competence to operate a unit

operation.

An analysis of the processes

A range of processes were examined as part of this project and these are

summarised in Appendix 2.

While the processes are widely varied, common themes emerge which lead to

relevant unit operations. Common process steps for upstream processing

include:

■ size reduction

■ particulate transport and storage

■ pelletising, sintering

■ loading (eg ship)

■ wet chemical dissolution or extraction processes (leaching, digestion,

dissolving)

■ separation (flotation, gravity, magnetic/electrical)

■ clarification/thickening



■ precipitation, complexing

■ high temperature processes (generally involving a chemical reaction,

calcining, smelting)

■ melting (high temperature processes involving only physical change)

■ electrolysis/electrochemical reactions

An examination of each of these will reveal the relevant unit operations and so

any required gaps in units of competency. This is undertaken in the next section.

Common processes for downstream processing include:

■ rolling

■ extrusion

■ coating (molten metal or polymer such as paint)

Downstream processing also includes casting (both die casting and foundry

casting) which is already covered (MEM05 Field 4) and so is not further

considered in this project.

Ancillary processes

These processes all occur on a large scale and often in remote areas. There are

many supporting ancillary processes ranging from pumping and the like through

to power station operation and water treatment (for disposal, for use as potable

water and things in between). These have not been the focus of this project but

are examined briefly in their own section.

Off gases, wastes and by-products

A quick examination of the processes shows that many of them produce

undesirable off gases such as SO2 (acid rain) and CO2 (climate change) in large

quantities. Some plants simply vent these gases. Others collect the SO2 and

convert it into H2SO4 which is a valuable by-product, or a material used in the

process. As the awareness of sustainability issues continues to increase and the

regulatory environment tightens we may expect to see more of this effort at

abatement and the creation of by-products from wastes.

Most solid waste is simply stored or returned to the mine site. Some is

reprocessed to recover more metals from them. Some solid waste is able to be

used as a raw material in other products/processes.

The production of by-products has not been examined by this project as it would

typically be considered as part of the heavy chemical sector which is already

covered by PMA.



Boundary issues with RII09

This is an area of natural overlap with RII09. Some processes occur both as part

of mining and resources as well as downstream processing. Often the location of

the processing as being on either a mining site or a processing site will depend

on where the company decides to put its boundary between the two. Relevant

RII09 units are included in Appendix 2. It is possible to use these units where

appropriate, provided they are a fit with PMA.

Boundary issues with PMC10

PMC10 has a similar design philosophy to PMA08. Both also have a similar

history in that they consist of disparate subsectors who have been cajoled into

working together within a Training Package. Both also had pre Training

Package suites of recognised units of competency which have been melded into

a consistent suite within a single Training Package5. The manufacture of cement

and glass has cultural and process similarities to PMA sectors. The manufacture

of concrete pavers, hand moulding and making fibrous plaster products bear

little similarity to the PMA sector. The ‘glue’ binding them together into

PMC10 (apart from history) is that significant companies in the sector (such as

Boral) operate in many of these sub sectors.

The PMA10 units of relevance to metalliferous processing typically come from

the capital and energy intensive end (eg cement and glass)

Unit operations in the processes

As discussed above there are a range of groups of processes which while

variably applied across the industry are common to many processes. While we

could look at having specialised units for each sector of this industry, this is not

consistent with the design philosophy of PMA and so they are examined with a

view to determining the underlying unit operations for each group.

Size reduction

Crushing and grinding is a feature of most of these processes as the ore is

reduced to the right particle size for further processing. Crushing and grinding is

already covered in the PMC10 Manufactured Mineral Products Training

Package. These units are:

■ PMC552003C Operate grinding equipment

■ PMC552008B Operate crushing equipment

5 PMA has been formed from the chemical and petrochemical industries (which themselves have

traditional sub sectors), the oil refining industry and both the transmission and processing hydrocarbon

subsectors. PMC has been formed from cement, concrete (premix and precast), clay, ceramic and glass

subsectors)



Screening however is not explicitly covered. Screening is relevant to the

metalliferous sector.

There is a fertiliser company in Hobart which uses the PMC Package for its

process operators. Normally one would expect fertiliser to fit nicely in PMA,

but in their case, crushing and particulate handling was significant and so PMC

was a better fit. While not part of this project, this is another example of the

need to include size reduction in PMA.

Particulate transport and storage

While the metalliferous sector does process fluids, they are mainly solutions and

suspensions with the materials and products being solids. However, while PMA

may be thought of as a fluid processing6 Training Package, particulate transport

and storage are covered by both PMA and PMC. These units are:

■ PMAOPS210B Operate particulates handling equipment (particulate

conveyors)

■ PMAOPS309B Operate particulates handling/ storage equipment (includes

managing storage facility)

■ PMC552002C Operate equipment to blend/mix materials (using particulate

blending equipment)

■ PMC562070B Move materials (use of front end loaders etc)

■ PMC562071C Operate bulk materials handling equipment (conveyors and

bulk particulates storage)

There is bound to be some overlap here between PMAOPS309 and

PMC562071. Either or both should be applicable to the metalliferous sector.

There is scope to examine this group of units and to develop from them a

consistent suite of particulate transport and storage units which is applicable

across PMC and the expanded PMA sectors.

The use of trains and trucks to convey particulates is not covered in either, and

this is probably outside the scope of PMA anyway.

Pelletising and sintering

While most effort is put into size reduction, the aggregation of fines into usable

sized particles is important as it facilitates the flow through of furnace gases and

makes otherwise low value fines more marketable.

There are no PMA or PMC units in this area.

RII09 however does have units in this area:

6 A perception which is not quite accurate



■ RIIPSM202A Prepare for pelletising activities

■ RIIPSM203A Produce pellets

■ RIIPRE203A Prepare for sintering activities

■ RIIPRE204A Sinter materials

These units seem to reflect what would appear to be the design philosophy of

the RII Training Package of designing units of competency around job

components. This is a different design philosophy to PMA.

Sintering may also be done by heating which is examined below.

Loading

Loading of bulk particulate solids is a significant feature of much of this sector

as significant quantities of raw materials, semi processed materials and bulk

metal oxides are shipped. PMA has a unit for loading fluids onto ships

(PMAOPS312B Undertake ship loading/unloading operations) which is well

utilised by some sectors. There is no PM unit for bulk loading of particulates

and while there would be similarities, there would also be significant

differences.

RII09 does have loading units:

■ RIIPEO204A Conduct shore side mooring operations

■ RIIPEO205A Conduct ship loading operations

Wet chemical dissolution

There are many processes which fit under this general heading. Some of them

are:

■ leaching

■ digestion

■ dissolving

■ solvent extraction

These are not different names for identical processes, however the result is the

same, one or more components of the original solid are now in solution. This

often occurs at elevated temperatures.

For a material to dissolve, a chemical reaction (often a very simple one) has

occurred and so we could possibly use:

■ PMAOPS220B Monitor chemical reactions in the process and

In PMA these would

probably be one unit

In PMA these would

probably be one unit



■ PMAOPS302B Operate reactors and reaction equipment

for this. However, these do not really cover these processes.

RII09 has individual units for each of these:

■ RIIPBE306A Conduct leaching process

■ RIIPBE202A Conduct digestion process

■ RIIPRE201A Conduct solvent extraction

Separation

Separation is an area where there are many different ways of doing it, but a few

common principles covering the main types of separation processes. PMA

provides a suite of three separation units of competency:

■ PMAOPS206B Operate separation equipment

• typically dual phase

• includes:

− cyclones

− hydrocyclones

− scrubbers

− knockout drums

− demisters/drift eliminators

− simple filters (cartridge, basket, sand etc)

■ PMAOPS207B Operate powered separation equipment

• uses power to drive the separator

• typically dual phase feed

• includes:

− centrifuges,

− scraped filters,

− rotary vacuum filters

− rotary driers

■ PMAOPS208B Operate chemical separation equipment

• typically single phase feed

• phase change or chemical process occurs

• includes:

− ion exchange

− absorbers and adsorbers

− precipitators

− crystallisers

− scrubbers

There are also separate units covering specialised separation processes such as

filtration and distillation.



In the metalliferous sector separation typically includes:

■ selective froth flotation – different operating principles to the above,

■ gravity separation – could be covered by PMAOPS206B (see also below),

■ separation based on differing magnetic or electrical properties – different

operating principles to the above.

So these processes are not well covered by PMA.

RII09 covers them with:

■ RIIPBE309A Conduct wet gravity separation

■ RIIPBE310A Conduct flotation process

■ RIIPBE311A Conduct magnetic separation

Separation based on electrical properties does not seem to be covered.

This is an area where the range of existing separation units should be examined

and a consistent suite of units covering all processes used by all relevant sectors

developed. The existing division of separation into three units has worked but in

the broader context appears to be lacking.

Clarification/thickening

Clarification is much the same as gravity separation or thickening. The

difference typically is that clarification is when the desired product is a clear

liquid overflow whereas thickening is when a high concentration sludge being

withdrawn from the base is the product. Gravity separation is similar.

PMA would cover this with


RII09 covers this with:

■ RIIPBE308A Conduct thickening and clarifying process

It appears there may be an opportunity to re-examine the suite of separation

units and identify if there is a better way of splitting them up as suggested above

(rather than just write one for every way of doing it).

Precipitation, complexing

Precipitation is causing a chemical reaction to occur where at least one of the

products is a solid. It is a common chemical technique to separate two

components of a solution. Complexing is similar but rather than a simple

chemical compound being formed, a chemical complex is formed. Either way

these could be covered by:



■ PMAOPS220B Monitor chemical reactions in the process and/or

■ PMAOPS302B Operate reactors and reaction equipment

PMAOPS302B is the most likely one as it is better aligned to continuous

reactors (PMAOPS220B being more targeted at batch reactors).

There are some specific issues associated with precipitation reactions however

and this process could equally be covered by:


The coverage of precipitation/complexing should be included in the review of

the units covering separation.

High temperature processes

High temperature processes covers a range of equipment, processes and

methods of heating. In this sector the high temperature process is usually

intended to cause a chemical reaction (ie it’s not just melting). The typical

reactions caused are:

■ calcination (the use of heat to produce a metal oxide by driving off combined

water, CO2 or SO2)

■ smelting/roasting (reducing a sulphide ore to its metal and SO2)

■ reduction (reducing an oxide ore to its metal using C (or other reductant) and

producing CO2 (or other oxide gas))

Heat may be caused by:

■ the burning of fuel (which does not take part in the reaction)

■ the use of an exothermic reaction - reduction is an example here as the C:

• produces heat

• acts as a chemical reductant

• produces CO2 off gas

■ the use of electrodes/electric arc (as a means of heat – see below for

electrolysis/electrochemical reactions)

In addition to this, the physical piece of plant may be:

■ stationary

■ rotating/reverberating

■ fluidised bed

PMA and PMC have several units related to high temperature:



■ PMAOPS303B Operate furnaces to induce reaction

■ PMAOPS323A Operate and monitor heating furnace

■ PMC552010C Operate a calcining kiln (written for but not restricted to

cement)

■ PMC552030C Operate a firing kiln (for clay and ceramics)

■ PMC552040C Operate glass melting process (this is just a heating process)

■ PMC553010C Process raw meal into product (for cement)

The large number of PMC units reflects both the history of that Training

Package and the fact that there are many high temperature processes with subtle

differences in that sector.

MEM05 also contains units related to high temperature processes, although

these are restricted to purely physical operation such as melting and casting:

■ MEM04001A Operate melting furnaces

■ MEM13004A Work safely with molten metals/glass

■ MEM04007A Pour molten metal

This would appear to be an opportunity to rationalise all these high temperature

process units and ensure they cover all sectors without gaps or unnecessary

duplication.

Electrolysis/electrochemical reactions

Apart from using electricity to produce heat (which is included above),

electricity is also used to induce electrochemical reactions which may be to:

■ precipitate a metal from its ion in a solution (eg electrowinning of Cu using

SX-EW, Mg, Zn)

■ liberate a metal from a compound (eg Al from Al2O3)

■ purify a metal by oxidising it at the anode and then reducing the purified

metal at the cathode (eg Cu, Au).

These are quite different operations. However the use of electrochemical

reactions is not limited to the metalliferous sector. An electrochemical reaction

is the basis of the production of chlorine gas (Cl2) from brine (NaCl) with the

valuable by-products of caustic soda (NaOH), hydrogen gas (H2) and sodium

hypochlorite (NaClO – commonly known as ‘liquid chlorine’). Metallic sodium

(Na) is also produced this way (using the old mercury cells) except that it isn’t

in Australia. Membrane cells are now used in Australia to produce Cl2 and its

by-products.

fairly self explanatory



RII09 provides the following:

■ RIIPRE202A Prepare and carry out electrolytic cleaning process

■ RIIPRE301A Conduct electrowinning/electrorefining operations

This is an area which is currently lacking in PMA. The RII units probably cover

their metalliferous areas adequately but not other electrochemical processes.

The need for an additional unit or two should be explored.

Downstream processes

While there are nine units of competency in tga7 covering extrusion, these are

specific to polymers, clay/concrete products and foods. The issues with all of

these materials are different to those of extruding metals. There are also issues

around die correcting for metal extrusion. There are similar issues covered in

PMB07 related to polymer extrusion (and also polymer moulding), but the

issues for metal extrusion are not covered.

There appear to be no units related to the rolling/milling of slab/blooms/ingots

Downstream processing also covers things like:

■ galvanising (or zincalume8 coating)

■ powder coating (of individual components)

■ continuous coating of strip (eg ‘Colorbond8’)

There are many units on tga related to coatings, but none seem to apply to

coating with molten metal (galvanising/zincalume). There is a unit in PMB07

(PMBPROD323C Produce powder coated products) which would be applicable

to the powder coating of individual metal components. This should be validated

with potential metal users.

Continuous painting and oven curing of strip steel (eg bare metal, galvanised or

zincalume) would not appear to be covered.

7 Tga – training.gov.au the official database of endorsed units of competency in Australia

8 These are BlueScope trademarked terms although in common use



Unit operations in ancillary processes

Due both to the scale of operation and the remoteness of many operations, sites

in this sector often have significant ancillary processes which might be

undertaken externally, often by government authorities or business, in other

sectors. In this regard it is similar to the hydrocarbons sector. Typical ancillary

processes include:

■ power generation

■ solid waste disposal – typically ‘tailings’

■ capture of waste energy from processes, by heat exchange/waste heat boilers

or using wastes as fuel

■ gaseous waste disposal which may be:

• vented (as is typically the case with CO2)

• converted into a by-product (eg H2SO4, NaClO)

• removed from the gas stream and disposed of as solid or liquid waste

■ water treatment which may include:

• liquid waste disposal – most liquid waste is aqueous and needs to be

treated to either EPA or trade waste licence requirements

• treating water to process water standards

• treating water to potable water standards

PMA approached water treatment with the review for coal seam gas (CSG). As

water treatment and disposal (either for use or to the environment) is a

significant part of CSG, the relevant unit was imported from the Water Training

Package (NWP357B Monitor, operate and control reverse osmosis and nano

filtration processes).

The PMA Training Package has always maintained the view that waste

treatment is just another process and that it was covered by the existing units of

competency. This is largely true, particularly when that waste treatment results

in the production of a by-product. By-product production has been largely

ignored by this report as they would seem to be covered by the existing units of

competency.

There are however special issues relating to the disposal of treated waste which

are not part of the existing units.

It appears to be appropriate to review this entire area of ancillary processes with

a view to:

■ ensuring the applicability of existing units is more obvious

■ covering the issues around the actual disposal/discharge of waste

■ importing or developing any required units.

applicable in remote areas where

available water is too saline



Current training and qualification approaches

The majority of the training is delivered in house with varying arrangements

with and input from RTOs. Some organisations are RTOs. The predilection to in

house training is driven by:

■ the specialist nature of the skills required

■ the remoteness of some operations

■ the lack of external RTOs with the willingness and expertise to deliver

■ these are large organisations who can generally sustain the budget required

for specialist in house training and assessment.

Having said this, some do have productive relationships with external RTOs

who provide valuable services in the field of:

■ validation of assessment

■ issuing of qualifications

■ mapping of internal process and resources to recognised qualifications

■ professional expertise in the area of training and assessing resources.

Where training is aligned to a recognised qualification, RII09 would seem to be

the more used with PMA08 also used. This would seem to be partly related to

process but probably more related to the internal structures of the organisation

as to whether they perceive the process to be merely an adjunct to the mineral

extraction and its associated processing, or as a standalone process with

significant difference to the mineral extraction. These two approaches seem to

coexist quite happily. Some of the more strategic trainers seemed to like the

idea of having two different structures of qualifications available as it gave them

some flexibility which was otherwise lacking.

Recommendations and conclusions re units of competency

It would be possible to simply write/import additional units into PMA08 to

cover many of the gaps identified. However, this is an inefficient way of doing

this, outside the spirit of Training Packages and not compliant with the design

philosophy of PMA08 which aimed (generally successfully) at finding

commonalities within types of equipment and writing units which could be

contextualised to the vast array of subtly different plant and equipment which is

in use.

The changes which are seen as necessary are discussed below.



Individual units

Most individual units relate to specific unit operations and are discussed under

the headings of those operations below. However, due to the variety of plant and

equipment covered by the current PMA08, three generalist technical units have

always been included. These were intended to be adapted to cover any specific

item of equipment for which there is not an applicable unit of competency.

These three are:

■ MSAPMOPS100A - Use equipment

■ MSAPMOPS200A - Operate equipment

■ PMAOPS300B - Operate a production unit

While these units are generally applicable to the metalliferous processing sector

also, PMAOPS300B does have some items in the range which make it difficult

to apply outside the traditional area PMA08 has covered.

Recommend that MSAOPS100, MSAPMOPS200 and PMAOPS300 be reviewed to ensure they are suitable for the metalliferous processing sector

Minor review and validation of three units

Units related to unit operations

Size reduction

The existing units:

■ PMC552003C Operate grinding equipment

■ PMC552008B Operate crushing equipment

should be suitable. A unit on screening is required.

Recommend that PMC552003C and PMC552008B be validated for the metalliferous processing sector.

Recommend drafting a unit for screening

Validation of two existing units. Drafting and validation of one new unit.

Size aggregation

There are no PMA or PMC units covering this. The RII units would appear to

have come from a different design philosophy.

Recommend that an analysis be done with a view to developing one or two new units covering size aggregation (sintering/pellitising).

Development and validation of one or two new units.



Particulate transport and storage

The existing units:

■ PMAOPS210B Operate particulates handling equipment

■ PMAOPS309B Operate particulates handling/ storage equipment

■ PMC552002C Operate equipment to blend/mix materials

■ PMC562070B Move materials

■ PMC562071C Operate bulk materials handling equipment

probably cover the field but may be inconsistent and have overlaps between the

two Training Package sources.

Recommend that PMAOPS201B, PMAOPS309B, PMC552002C, PMC562070B and PMC562071C be reviewed with the view of creating one consistent suite of units covering existing PMA, metalliferous and PMC and to include units on:

• mechanical conveying (belts etc)

• pneumatic conveying (pressure or vacuum)

• management of storage vessels (eg silos)

• management of open storage (eg heaps on the ground)

• particulates blending by use of a blending/mixing equipment

• particulates blending by use of front end loaders etc

and the importation of units relevant to the operation of appropriate mobile plant.

Recasting of five existing units into six new units. Identification of appropriate mobile plant units. Validation of all units with relevant sectors.

NOTE conveying by truck or train is not included.

Loading

PMAOPS312B Undertake ship loading_unloading operations is specific to the

loading of fluids, particularly hazardous fluids. The two RII units have been

written to be specific to metalliferous mining.

Recommend that analysis be done to develop one mooring unit (to be relevant to all of PMA) and one ship loading unit specific to loading of bulk particulates. Modification of the title of PMAOPS312 to make it clear it applies to fluids.



Two new units, one minor modification.

Wet chemical dissolution

There are no appropriate PMA units here. The RII units have been written to

apply to metalliferous mining.

Recommend that analysis be done to develop up to four new units covering wet chemical dissolution.

Up to four new units.

Separation

There are three existing unit in PMA:


■ PMAOPS207B Operate powered separation equipment


which do not really cover

■ selective froth flotation

■ magnetic or electrical separation

Recommend reviewing the three PMA units (PMAOPS 206, 207, 208) and conducting analysis to develop units covering froth flotation and electrical/ magnetic separation. This suite to also include clarification and thickening/ gravity separation. This may require another unit.

Two, maybe three, new units. Review and possible recasting of three existing units. Validation with relevant sectors.

Precipitation, complexing

Existing units do not cover this well.

Recommend conducting analysis with a view to developing one new unit covering precipitation/complexing

One new unit.

High temperature processes

High temperature processes are already part of PMA and PMC with an existing

6 units. MEM is also involved (MEM04001B). However while these units are

important for their sectors they are typically just another plant unit. In the

metalliferous sector, high temperature processes seem to take a higher degree of

significance, probably due to their tonnage and so the quantity of heat

consumed/given out.



The permutations and combination of type of furnace, purpose of furnace, type

of heating and type of reaction occurring (if there is one at all), all lead to a

potentially vast number of units. However, it should not be necessary to have

one unit for each of these possible combinations. It is proposed to re-examine

the area of high temperature processes and develop a suite of units which will

cover existing PMA, metalliferous and PMC needs. The existing MEM unit is

essentially serving a different market and need not be included in this.

Recommend reviewing existing six units and develop six to eight new units and validate with all relevant sectors.

Electrolysis/electrochemical reactions

There are no PMA or PMC units in this area and the RII units are limited in

their focus. It is proposed that this be analysed and a small suite of new units

developed covering electrochemical processes for metalliferous and chemical

sectors.

Recommend conducting analysis and developing around three new units.

Extrusion (eg Al, Cu)

There are no existing units here. While extrusion itself is a single process, it is

supported by other processes. There are probably five or six units needed here.

Anodising is covered by MEM08006B Produce clear and/or coloured and/or

sealed anodised films on aluminium. This needs to be imported into PMA for

ease of use by this sector and validated.

Powder coating is covered by PMBPROD323C Produce powder coated

products. This needs to be imported into PMA for ease of use by this sector and

validated.

This does not include die correcting which is the subject of a separate analysis

by MSA. Die correcting could be included in this project by MSA should they

wish.

Recommend conducting analysis and developing five or six new units, importing two units and validating (excludes die correcting).

Strip, billet, ingot casting

This is different to casting as occurs in foundries as it produces large, often

continuous blocks or slabs of solid metal, the first time it has been solid since

being formed. It is not to any specific customer shape as occurs in foundries. It

will be to a specific composition. There are no units covering this.

Recommend conducting analysis and developing and validating three of four new units.



Rolling, drawing

Rolling and drawing don’t seem to be covered. Rolling includes both hot and

cold rolling, roughing and rolling to a profile. Coiling may be able to be shared

with molten metal coating. We are probably looking at around six units.

Drawing is probably another two units.

Conduct analysis develop and validate eight new units.

Molten metal coating

Galvanising/zincalume coating does not seem to be covered in tga.

Electroplating is covered by MEM (Field 8). There are both continuous and

batch molten metal coating processes. They involve uncoiling (continuous),

cleaning (both), dipping (both) and then recoiling (continuous). Batch also

involves the handling and moving of the metal components being dipped. We

are probably looking at around six units.

Conduct analysis develop and validate six units

Continuous painting

Continuous painting of strip metal does not seem to be covered. We would seem

to have uncoiling and recoiling (shared with molten metal coating), cleaning,

coating and baking. We would also need to deal with the issue of colour and

colour changeover. We are probably dealing with another three or four units.

Conduct analysis develop and validate three or four units

Waste treatment

The issue of units for waste treatment has been discussed above. The review of

separation units discussed in this section should cover most of the review of

existing PMA units. However, ‘ponding’ or tailings treatment is not covered and

is becoming more important and so probably should be covered. Issues related

to water disposal also need to be covered. This may result in the importation of

more units from NWP07 and possibly one or two new units focussed on the

needs of this industry. NWP units tend to focus on municipal treatment – ie after

it has left the manufacturing plant.

Conduct analysis and develop up to two new units. Review NWP07 units and import as relevant. Validate units with relevant sectors.

Summary of recommendations

This section has recommended:

■ minor review of 4 PMA units

■ review 14 PMA/PMC units and create 17-20 new PMA units



■ validation of 2 PMC units for the metalliferous sector (assuming no review

required)

■ conduct analysis and develop 39-43 new units

■ import 7-9 units from relevant Training Packages

■ validate all units (with both relevant PMA and PMC sectors

■ import relevant new or modified PMA units back into PMC

■ make appropriate modifications to existing qualifications by inserting the

units into the relevant groups and validating the revised qualifications.



Appendix 1 Persons contacted

Sites visited as part of the field research

The following persons contributed to this project through meeting with us and

discussing their needs, showing us over their process or otherwise. Their input

is gratefully acknowledged.

Name Organisation Sector State Chester Church Alcoa World Alumina Australia Alumina WA

Anita

Anthony

Dwayne

Fortsch

Giblett

Huxley

Citic Pacific Mining Management

Pty Ltd

Iron WA

David

Steve

Harvey

Sterling

Newmont Asia Pacific (Boddington

Gold)

Gold WA

Dean

Eddie

Tim

Anderson

Saville

Wilson-

Haffenden

Nyrstar Hobart Zinc TAS

Ron Chell Rio Tinto Iron WA

Peter

Sheryl

Jason

Rodgers

Clarke

Boyes

Simcoa Operations Pty Ltd Silicon WA

Jeremy Rose Skills Tasmania Other TAS

Annette Hennessy TEMCO Manganese TAS

Lyn Jones Tiwest Titanium WA

Peter

Shawn

Michelle

Hamence

Gurney

Piggot

OneSteel Whyalla Steel SA

Lynn

Danny

Wallace

Champion

Nyrstar Port Pirie Lead SA

Keith Hillier BlueScope Steel Steel NSW

Mick

Geoff

Davies

Allen

Sun Metals Corporation Zinc QLD

Mary-

Anne

Rob

Alex

Ridgill

Palmer

Stanojevic

Capral

AiG

Aluminium QLD

Bianca Standing Olympic Dam Cu, U, Ag,

Au

SA9

9 The site was visited on a public visit and Bianca and others contacted by phone/email



Sites contacted but where no visit occurred

For various reasons these people did not feel able to have an on-site discussion.

Many expressed willingness to review reports sent to them.

Name Organisation Sector State Sandra McCormick Queensland Nickel Pty Ltd Nickel QLD

Tanya Hunt Queensland Magnesia Magnesium QLD

Joel Turner OneSteel Rooty Hill Steel NSW

Jen Lojszczyk OneSteel Waratah Steel NSW

Jenny Summers Xstrata Copper Copper QLD

Lincoln Mandry Worsley Alumina Aluminium WA

Hayden Davey Nickel West Nickel WA

Dean Burgess Cristal Global Titanium WA



Appendix 2 Metalliferous processes and related units

The following sections represent a summary of the processes used and the

mapping of these unit operations to the relevant units of competency. They are

arranged in alphabetical order.

Those with a * in the title have not had a site visit and so the material included

is from desk research only.

NOTE the discussion and tables below concentrate on the main process units

and does not cover supporting equipment such as pumps, compressors or

controls which are regarded as generic.

Aluminium (Al)

Mineral source

The mineral source is bauxite which is a mixture of

■ gibbsite (Al203.3H20),

■ boehmite (Al203.H20), and

■ diaspore (Al203.H20)

Product(s)

Bauxite is processed (refined) to alumina (Al2O3) which is both a product that is

sold and an intermediary to producing aluminium metal (Al)

The alumina (white powder) may be sold as a product, for refractories, catalysts,

welding rods etc or (the bulk of it) as a feed for aluminium smelting.

Summary of processing

Refining (to Al2O3) uses the Bayer process and follows four basic steps:

■ digestion10

Al2O3 + 6 NaOH 2 Al(OH)3

■ clarification gravity separation of Al(OH)3 solution from red mud (SiO2

(sand), TiO2 and Fe2O3)

■ precipitation production of Al(OH)3 crystals

■ calcination 2Al(OH)3 Al2O3 + 3 H2O

Smelting uses the Hall-Heroult process where an electrochemical process

converts the alumina to aluminium. This uses carbon anodes (which react) and a

bath of molten cryolite (Na3AlF6) as the electrolyte.

10

indicates application of heat

1030oC



2Al2O3 4Al + 3 CO2

The Al is sold as ingots.

The process by unit of competency – Al2O3 refining

RII09 unit Process step PMA08/PMC10 unit Comment RIIPEO201A Conduct

conveyor operations Bauxite delivery – belt

or train

PMAOPS210B Operate

particulates handling

equipment

RIIPHA301A Conduct

milling/grinding Grinding

PMC552003C Operate

grinding equipment

Digestion

PMAOPS220B Monitor

chemical reactions in the

process

PMAOPS302B Operate

reactors and reaction

equipment

RIIPBE308A Conduct

thickening and clarifying

process Clarification

PMAOPS206B Operate

separation equipment

Precipitation

Washing

Air drying

Cyclone separation

PMAOPS206B Operate


Calcining

PMC552010C Operate a

calcining kiln

Is not specific to fluidised

bed

Cyclone separation

PMAOPS206B Operate


Bulk storage

PMAOPS309B Operate

particulates handling/

storage equipment

Bulk loading

Loading of particulates

Supporting processes

Power station

MEM07034A Operate and

monitor intermediate class

boiler

PMAOPS325B Generate

electrical power

Retention basin/tailings

dam

Oxalate removal

PMAOPS290B Operate a

biotreater

The process by unit of competency – Al smelting

RII09 unit Process step PMA08/PMC10 unit Comment

anode




conveyor operations Alumina delivery – ship

and conveyor

PMAOPS210B Operate


equipment

Charge cells

PMASMELT264B Start up

reduction cells

Maintain electrodes

PMASMELT260B Form

carbon anodes.

PMASMELT261B Bake

carbon anodes

PMASMELT262B Clean

and strip anode rods

PMASMELT263B Spray

carbon anodes

Operate cells

PMASMELT265B Operate

reduction cells

Tap cells

PMASMELT266B Deliver

molten metal

Cast ingots

PMASMELT267B Cast

aluminium ingots

PMASMELT268B Vertical

direct casting

PMASMELT269A Operate

cell tending equipment

PMASMELT270A Supply

product from reduction cells

Copper (Cu)

Mineral source

The major mineral source in Australia is chalcopyrite (CuFeS2).

Olympic Dam produce Cu with a U by-product.

Product(s)

The ore is processed by a number of processes to Cu. Intermediates may be

traded but there is no actual intermediate product.

There are often by-product metals such as Zn, Pb, Au or U


There are a number of possible processes for recovering Cu from its ore. All

processes seem to start with crushing/grinding of the ore to obtain the right

particle size.

Traditional processing starts with ore flotation to concentrate the ore followed

by smelting:

CuFeS2 + flux CuS + FeS smelt

copper matte



CuS + FeS + flux Cu

Blister copper electrolytic copper (100%)

It may also be flash-smelted directly to blister copper

CuFeS2 + 2O2 Cu + 2SO2 + slag

Alternatively the entire smelting process may be bypassed if the ore is in the

form of a copper oxide and the process of solution exchange electrowinning

(SX-EW) used. Here the copper is leached from the ore, concentrated using a

complexing agent and then won from the copper complex in an electrochemical

process.

CuO + H2SO4 CuSO4 + H2O

CuSO4 + complexing agent Cu complex

Cu complex Cu

The Olympic Dam process produces a concentrated CuS by froth flotation and

then blister copper by smelting with O2. Electrolytic copper is then produced

from the blister copper. The by-product is U (and Au and Ag)

The process by unit of competency – Cu

RII09 unit Process step PMA08/PMC10 unit Comment RIIPHA301A Conduct

milling/grinding

RIIPRO201A Conduct

crushing operations

Size reduction

PMC552003C Operate

grinding equipment

PMC552008B Operate

crushing equipment

RIIPBE310A Conduct

flotation process Flotation/concentration

RIIPSM201A Tap furnaces

RIIPSM304A Operate

furnaces Smelting/flash smelting

PMAOPS303B Operate

furnaces to induce reaction

RIIPSM305A Operate

converters Converting

PMAOPS303B Operate


RIIPBE306A Conduct

leaching process Leaching

PMAOPS220B Monitor


process

PMAOPS302B Operate


equipment

These do cover it but are not

well targeted for this

operation

RIIPRE301A Conduct

electrowinning/

electrorefining operations Electrochemical

conversion

While there are general

reaction units and a specific

Al unit, there is nothing

which really covers this

converter

blister copper (98%)

smelt



Gold (Au)

Mineral source

Au is one of the few elements to commonly occur in its metallic state. It is

commonly found with sulphide minerals such as pyrite (FeS2), but does not

occur as a sulphide ore itself.

Au also occurs as a by-product of Cu.

Product(s)

The ore is processed by a number of processes to Au. Gold bearing

intermediates are traded, typically as by-product streams from Cu.


Most of the processing of gold is to remove very fine gold grains from a rock

matrix. Crushing and grinding is the first step with cyclones being used for

sizing. Oversize is returned for further crushing with undersize slurry being sent

to flash flotation cells and thickeners to separate the Cu/Au mix from the Au

stream. The Cu/Au stream is concentrated and filtered to remove liquid and

shipped to another processes to separate the Cu and Au.

Au stream is leached from the ore using sodium cyanide (NaCN) and oxygen

(O2).The AuCN is adsorbed onto activated carbon.

Au + NaCN + O2 AuCN

The AuCN is then taken to an elution process where it is acid washed to liberate

the Au.

The liberated Au then goes to the gold room where an electrowinning process

produces dorè (Au mixed with Ag and Cu). After electrowinning the dorè is

melted and cast as dorè ingots.

Other sources see the Au held in a metal sulphide ore. Where the gold is held in

a sulphide ore, this will need to be broken down before cyaniding. This can be

done by roasting:

MS + O2 MO+ SO2

This then liberates the gold containing rock for further processing as above.

The process by unit of competency – Au

RII09 unit Process step PMA08/PMC10 unit Comment RIIMEX203A Break oversize

rock

RIIPRO202A Conduct

screening and conveying

operations

RIIPRO301A Conduct crushing

Crushing

PMC552008B Operate

crushing equipment

PMC552003C Operate

grinding equipment



RII09 unit Process step PMA08/PMC10 unit Comment and screening plant operations

RIIPHA301A Conduct milling

and grinding

RIIPEO201A Conduct

conveyor operations

RIIPRO202A Conduct


operations

Particulate conveying

PMAOPS210B Operate


equipment

RIIPBE310A Conduct flotation

process Flotation

RIIPBE308A Conduct


process

RIIPBE309A Conduct wet

gravity separation

Thickening

PMAOPS206B Operate


RIIPHA302A Operate and

monitor filter processes

RIIPBE303A Conduct filtering

process

Filtration

PMAOPS232B Produce

product by filtration

RIIPBE306A Conduct leaching

process Leaching

PMAOPS208B Operate

chemical separation

equipment

This is not quite right for

this

RIIPRE302A Conduct elution

processes Elution

PMAOPS220B Monitor


process

This is only a partial fit

RIIPRE301A Conduct

electrowinning/electrorefining

operations Electrowinning


reduction cells

Except this was written for

Al smelting only

RIIPRE303A Conduct gold

room operations

RIIPSM302A Cast Ingots

RIIPSM304A Operate Furnaces

Melting and casting


molten metal


Al smelting only

RIIWMG204A Reclaim and

treat water system

RIIWBP203A Monitor tailings

dam environment

RIIPBP201A Control acid

plant operations

RIIWBP202A Distribute

tailings

Residue disposal

The separation and the

reaction units could be

applied here

Iron and Steel (Fe)

Mineral source

The major mineral sources in Australia are hematite (Fe2O3) or magnetite

(Fe3O4) with most traditionally being from hematite although magnetite is of

growing importance.

Scrap steel is also a significant source of raw materials.



Product(s)

The ore is processed to produce Fe. There are many grades of Fe with markets

in all of them. The more highly processed grades are alloyed with a range of

other metals (typically Cr and Ni) to produce stainless steel.

Iron ore itself is a product and may be sold as ‘run of mine’ or it may be

processed to varying degrees controlling average composition and particle size.


Processing starts by size reduction (crushing and grinding) and transporting

(train, conveyor, ship).

Processing may be undertaken to concentrate the ore (higher concentration of

Fe) or for beneficiation – higher concentration and better physical form – eg

pelletising and/or sintering to increase particle size and make more uniform.

Pelletising may be done upstream near the mine and will simply make the

particle size larger and more uniform. Sintering is more likely to be done near

the steel production facility and to also include steel making additives

(limestone, carbon) in the sinter.

The production of pig iron using a blast furnace is the traditional first step of

producing Fe from ore:

2Fe2O3 + 3C 4Fe + 3CO2

The C provides both the source of heat and the chemical reductant. Limestone is

also used as a flux to help remove other impurities. Blast furnace slag is used in

making glass, cement and road base.

The pig iron is processed to steel using the basic oxygen steel (BOS) or electric

arc furnaces (EAF) processes. These processes may also be used to produce

steel from scrap steel. BOS also uses fluxes

Different grades are made by melting and adding a range of metal additives

while molten. Alternatively an existing impurity might be stripped out, eg the

removal of C by blowing air so burning off the C as CO2.

Once produced as a metal the steel may be cast, rolled and/or coated.

The process by unit of competency – Iron Ore concentration/ beneficiation


Train unloading

RIIPRO201A Conduct

crushing operations Crushing

PMC552008B Operate

crushing equipment

RIIPHA301A Conduct

milling/grinding Grinding

PMC552003C Operate

grinding equipment



RII09 unit Process step PMA08/PMC10 unit Comment PMAOPS217B Operate wet

milling equipment

RIIPEO201A Conduct

conveyor operations

RIIPRO202A Conduct


operations

Particulate conveying

PMAOPS210B Operate


equipment

Blending

PMC552002C Operate

equipment to blend/mix

materials

Cyclone separation

PMAOPS206B Operate


RIIPBE311A Conduct

magnetic separation Magnetic separation

RIIPBE308A Conduct


process Thickening

PMAOPS206B Operate


RIIPGP201A Conduct pump

operations Slurry pumping

PMAOPS221B Operate and

monitor prime movers

PMAOPS222B Operate and

monitor pumping systems

and equipment

RIIPBE303A Conduct

filtering process



Filtration

PMAOPS232B Produce


RIIPSM202A Prepare for

pelletising activities

RIIPSM203A Produce pellets Pelletising


calcining kiln


firing kiln

These may not be quite

right but would be a good

start

RIIPEO205A Conduct ship

loading operations Ship loading

Loading of solids

RIIMPO305A Conduct

stockpile dozer operations

RIIMPO306A Operate

plant/machinery on live

stockpiles

RIIMPO318A Conduct skid

steer loader operations

Mobile plant operation

PMC562070B Move

materials

Power generation

PMAOPS325B Generate

electrical power

Cooling towers

Desalination

NWP357B Monitor, operate

and control reverse osmosis

and nano filtration processes

The process by unit of competency – Fe production


Coking

PMAOPS303B Operate


This is not a good fit


RIIPSM301A Cast a blast Blast furnace

PMAOPS303B Operate





RII09 unit Process step PMA08/PMC10 unit Comment furnace

RIIPSM303A Operate a blast

furnace

RIIPSM304A Operate furnaces

BOS

PMAOPS303B Operate



EAF

RIIPSM306A Supply molten

metal and additives to furnaces

RIIPSM307A Control molten

metal in holding furnace/vessel

Alloying

PMAOPS323A Operate and

monitor heating furnace


Lead (Pb)

Mineral source

The major mineral source in Australia is galena (PbS). Cerussite (PbCO3) and

anglesite (PbSO4) are also sources. Pb is typically a co-product from Zn, Ag and

Cu.

Product(s)

The main product is Pb which is used as the metal. It used to be used as a petrol

additive (octane enhancer (CH3CH2)4Pb) but this is no longer used in Australia.

Its main current use is as electrodes in wet cell batteries. It is also a component

of pewter and may be used in other alloys.


The ore is crushed and ground to get the desired particle size. The ground ore is

then subject to selective foam flotation to separate the Pb ore from the other

metals and mineral waste. This leads to a concentrated ore.

The fine particles are sintered and then smelted to produce 97% Pb.

PbS + O2 Pb + SO2

Cooling and solidification is controlled to allow trace Cu to float to the surface

as dross. The dross is recycled to the smelting furnace. This Pb may be cast as

ingots.

The crude Pb will then be remelted and air blown through to form a slag mainly

of antinomy (Sb) and arsenic (As). Au, Ag and Cu are also removed leaving

99.9%Pb which is cast as an ingot.

The process by unit of competency – Pb

RII09 unit Process step PMA08/PMC10 unit Comment RIIPRO201A Conduct crushing

operations Crushing and grinding

PMC552008B Operate

crushing equipment



RII09 unit Process step PMA08/PMC10 unit Comment RIIPHA301A Conduct

milling/grinding

PMC552003C Operate

grinding equipment


process Flotation

PMAOPS206B Operate


This is a partial fit

RIIPRE203A Prepare for

sintering activities

RIIPRE204A Sinter materials Sintering


RIIPSM304A Operate furnaces Smelting

PMAOPS303B Operate



RIIPSM304A Operate furnaces

Refining



Magnesium (Mg)*

Mineral source

The major mineral source in Australia is magnesite (MgCO3). Mg also occurs in

dolomite (CaMg(CO3)2).

Product(s)

Magnesium is the lightest of metals which can be used as a metal (SG = 1.74,

Al SG = 2.7) and most of its use comes from that (along with its impact

strength).

Magnesite and magnesia (MgO or Mg(OH)2 if in solution such as milk of

magnesia) are also products. MgO is used for refractories and MgCO3 is a slag

former in steel making and also a raw material for the chemical industry and

construction industry.


The ore is crushed, screened and washed.

The crude MgCO3 is then calcined to produce ‘caustic magnesia’

MgCO3 MgO + CO2

Caustic magnesia is calcined at 700 – 1000oC and is able to absorb liquids,

heavy metals and ions and so is used in water treatment. If then calcined at 1530

– 2300oC it is known as ‘dead burned’ or sintered magnesia and is suitable for

refractories. It may be further calcined at 2800oC to form electrofused magnesia

for premium grade refractories.

Mg is made from MgO by first dissolving in HCl and then electrolysing in a

process similar to Al smelting. The liberated Cl2 is recycled and remanufactured

to HCl.

MgO + 2HCl MgCl2 + H2O

MgCl2 Mg + Cl2



The process by unit of competency – MgO


operations

RIIPHA301A Conduct

milling/grinding

Crushing and grinding

PMC552008B Operate

crushing equipment

PMC552003C Operate

grinding equipment

RIIPBE301A Conduct

calcinations activities Calcining


calcining kiln

The process by unit of competency – Mg


Dissolution

PMAOPS220B Monitor


process

PMAOPS302B Operate


equipment

Electrolysis

Manganese (Mn)

Mineral source

The major mineral source is pyrolusite (MnO2) and occurs mixed with iron ores.

Product(s)

Mn is mainly used as an alloying element for steel of various grades.

When produced for alloying it is in the form of standard (or high carbon)

ferromanganese (>76% Mn and ~ 7% C) with lower C higher Mn grades also

being available, or silicomanganese (14-16% Si, 65-68% Mn, ~ 2% C). Special

grades may contain < 30% Si with lower C.

It is also used as a pigment for glass, in dry cell batteries and for varying

chemicals including the common Condy’s crystals (KMnO4).


The MnO2 (along with the Fe in the ore) is mixed with C (acting as a reductant)

and the fluxes (slag formers) dolomite (CaMg(CO3)2) and limestone (CaCO3).

These are charged to an electric arc furnace to produce ferromanganese.

2MnO2 + 2Fe2O3 + 5C 2Mn, 4Fe + 5CO2

Should silicomanganese be the required product, quartzite (SiO2) is added. Slag

from the production of ferromanganese is also crushed and used to recover Mn

remaining in the slag. The SiO2 is also reduced in an arc furnace.



MnO2 + SiO2 + 2C Mn, Si + 2CO2

Reactants are charged to the top of the furnace which is periodically tapped with

the ferromanganese or silicomanganese being either cast on a casting floor or

into ingots. The crushed product is bagged or loaded into a rubber lined

container for shipping.

The furnaces also produce CO off gas which is scrubbed and used as a fuel for

power generation.

Mn ore fines are also sintered in a furnace to form a particle size suitable for

charging to the arc furnace.

A fume dam is also used to treat wash water from the scrubber.

The process by unit of competency

RII09 unit Process step PMA08/PMC10 unit Comment RIIPSM304A Operate furnaces

Arc furnace

PMAOPS303B Operate

furnaces to induce reaction RIIPSM201A Tap furnaces

Tapping

MEM13004A Work safely

with molten metals/glass

Casting

MEM04007A Pour molten

metal RIIPRO201A Conduct crushing

operations Crushing

PMC552008B Operate

crushing equipment

Bulk storage

PMAOPS309B Operate


storage equipment


Gas scrubbing

PMAOPS208B Operate

chemical separation

equipment

Power station



boiler

PMAOPS325B Generate

electrical power


treat water system Settling dam

PMAOPS206B Operate


Refractory relining

PMC552091B Prepare for,

install and repair refractory

brickwork/blockwork

Nickel (Ni)*

Mineral source

The major mineral source in Australia is pentlandite (Fe, Ni)9S8 and occurs

mixed with other ores such as pyrite (FeS) and chalcopyrite (CuFeS2).



Lateritic ores are also being developed and imported lateritic ores are being

processed. The mineral ore in laterite tends to be Ni mixed with hydrated iron

oxide.

Product(s)

Ni is mainly used as an alloying element for steel of various grades.


The ore is crushed and ground and then separated from the gangue by flotation.

This concentrates the Ni content of the ore.

Smelting of ore produces nickel matte (71% Ni, 5% Cu and FeS). Granulated

nickel matte is then refined to Ni. Refining is done using NH3 under pressure to

leach the Ni from the matte (as an amine complex). H2S then removes the Cu

(CuS) and finally H2 under pressure precipitates the Ni. Remaining Ni and Co

are precipitated by more H2S with (NH4)2SO4 being crystallised from the

remaining liquor and sold as fertiliser.

(Fe, Ni)9S8 Ni + FeS

Ni + X NH3 Ni.X NH3

Cu2+

+ H2S CuS + H2

For lateritic ore, high temperature pressure acid leaching followed by ammonia

solvent extraction yields NiCO3. Heating produces a sinter of mixed Ni and

NiO.

The process by unit of competency – Ni


operations

RIIPHA301A Conduct

milling/grinding


PMC552008B Operate

crushing equipment

PMC552003C Operate

grinding equipment


process Flotation

PMAOPS206B Operate



RIIPSM304A Operate furnaces Smelting

PMAOPS303B Operate


RIIPBE306A Conduct leaching

process Leaching

PMAOPS220B Monitor


process

PMAOPS302B Operate


equipment

RIIPBE203A Conduct

precipitation operations Precipitation

PMAOPS220B Monitor


process

PMAOPS302B Operate


equipment



Silicon (Si)

Mineral source

The major mineral source in Australia is quartzite (SiO2).

Product(s)

Si is used to make silicates (fillers for polymers), as a metallurgical alloying

material and as a chemical feedstock where it may end up as silanes (SinH2 n +2),

silicones (a compound of both organic and silicon molecules), silicon rubber or

of course as computer chips.


The quartzite is crushed and charged to an electric arc furnace for reduction

with C. The preferred C is charcoal as it is more pure than coal. Charcoal is

made by the partial combustion of timber:

(C6H10O5)n + O2 xC + 5nH2O +yCO2

The SiO2 is then reduced using C as the reductant and the arc furnace to provide

heat. This occurs as a two stage process.

SiO2 + 2C SiC + CO2 Si + C

Additives may be used to produce different grades.



conveyor operations

RIIPRO202A Conduct


operations

Quartzite delivery –

truck or train

PMAOPS210B Operate


equipment

Charcoal production

MSAPMOPS200A Operate

equipment

Charge quartzite and

reductant

PMAOPS210B Operate


equipment

PMAOPS309B Operate


storage equipment

Submerged arc furnace


reduction cells

PMAOPS303B Operate



Al smelting only

Furnace tapping and

casting


molten metal


Al smelting only

WIP storage



RII09 unit Process step PMA08/PMC10 unit Comment RIIPRO201A Conduct

crushing operations Crushing and screening

PMC552008B Operate

crushing equipment

Packaging

Packaging of particulate

solids.

Silver (Ag)*

Mineral source

Silver is manly a co-product of Cu, Pb, Zn and to a lesser extent Au. The major

mineral sources in Australia are tetrahedrite (Cu,Fe,Zn,Ag12Sb4S13), freibergite

(tetrahedrite with up to 30% Ag) and pyragyrite (Ag3SbS3) which occur in

galena (PbS).

Some is also produced from Cu and Au processing.

Product(s)

Photographic film was the major use for Ag (eg as AgCl) but with digital

photography displacing film it is now mainly used for electronics and

jewellery/tableware. It is also used in brazing and solder.


Processing starts with crushing and grinding followed by flotation to separate

the galena from the tailings. The concentrate is then sintered before smelting.

This is the Pb process and the Ag is recovered with the Pb.

To recover the Ag, the crude Pb is melted and poured through a layer of molten

zinc into a kettle where the rate of cooling and solidification is controlled to

allow the Ag, Au and Cu to float to the surface and form a molten alloy with the

Zn. The Zn layer is skimmed and the Ag, Au and Cu removed. An Ag/Au

mixture (called dorè) may be sent to an Au process for removal of the Ag.

The process by unit of competency – Ag

This is covered by the other processes already examined.

Tin (Sn)*

Mineral source

The major mineral source in Australia is cassiterite (SnO2) with a minor source

being stannites (Cu2FeSnS4). Cassiterite is usually contained in an alluvial layer.

Product(s)

Sn is used to coat steel, particularly for food containers. The other major use is

as an alloying material to make bronze, soft solder (although the use here is now

restricted due to restrictions on Pb) and as a bearing metal (eg white metal).




The alluvium is slurried and then subject to a series of gravity separation

techniques (jigs, spirals and shaking tables). Magnetic and electrostatic

separation may also be used. This may be followed by flotation. If hard rock is

the source it is first crushed and ground.

Cassiterite is then smelted in a reverberatory furnace using a C reductant.

Limestone and silica fluxes are also used. The Sn is cast into pigs while the slag

is crushed and resmelted as it contains 10- 25% Sn.

SnO2 + C Sn + CO2

The crude Sn is refined by heating to just above its melting point, so separating

it from the other metals. Electrolytic refining may also be used but it is more

expensive.


RII09 unit Process step PMA08/PMC10 unit Comment RIIPRO201A Conduct

crushing operations

RIIPHA301A Conduct

milling/grinding


PMC552008B Operate

crushing equipment

PMC552003C Operate

grinding equipment

Slurrying

RIIPBE309A Conduct wet

gravity separation Gravity separation,

flotation

PMAOPS206B Operate


RIIPBE311A Conduct

magnetic separation Magnetic/electrostatic

separation

RIIPSM304A Operate

furnaces Smelting

PMAOPS303B Operate


RIIPSM304A Operate

furnaces Refining



Titanium (Ti)

Mineral source

The major mineral sources in Australia are ilmenite (FeTiO3) and rutile (TiO2).

It is often found with zircon (ZrSiO4) and other mineral sands.

Product(s)

A major product is titanium dioxide (TiO2) which is a white pigment with high

opacity and brightness used in paint, ink, polymers and sunscreen.

Ti is also a product which is used in aerospace, yachts, medical implants and

other uses requiring strength, lightness and corrosion resistance.




Recovery of the mineral sands is typically by dredge, separating the mineral

sands from the sand which is returned. High concentration deposits may use

mechanical excavators.

‘Dry milling’ is used to separate the different mineral sands based on their

magnetic and electrical properties at elevated temperatures. The non-Ti mineral

sands are then packed and sold.

The Becher process is used to upgrade ilmenite to synthetic rutile. Here the iron

component is reduced to Fe and separated from the TiO2 (synthetic rutile) using

heat and a carbon reductant.

FeTiO3 + C TiO2 + Fe + CO

The synthetic rutile may be acid washed to further remove residual Fe. The

synthetic rutile may be further leached to remove other impurities, particularly

radioactive components to reduce radioactivity to internationally acceptable

levels.

Some ilmenite will require a chromium reduction process using high tension

electromagnetic separation to reduce Cr2O3 to < 0.4%.

TiO2 is made from synthetic rutile using a chlorine calcining process using a

fluidised bed reactor under pressure. The TiCl4 is then reacted with O2 to

produce TiO2.

SR + 2Cl2 TiCl4

TiCl4 + O2 TiO2

TiO2 is the final product. It may be acid washed, milled and/or coated

depending on the intended end use.

Ti is also made from TiCl4 which is reacted with Mg to yield Ti and MgCl2

TiCl4 + 2Mg Ti + 2MgCl2

The Ti is in the form of a ‘sponge’. Vacuum distillation allows the MgCl2 to be

removed and recycled. The Ti sponge is then melted and alloyed and cast into

slabs.

Ti metal does not appear to be produced in Australia.

The process by unit of competency mineral sand processing

RII09 unit Process step PMA08/PMC10 unit Comment RIIPBE304A Conduct heavy

media separation

RIIPBE311A Conduct

magnetic separation

Mineral separation



RII09 unit Process step PMA08/PMC10 unit Comment RIIPBE204A Conduct

reduction process Reduction


calcining kiln

PMAOPS303B Operate


This would be the unit,

except this is not calcining

RIIPBE201A Conduct

aeration process Aeration

RIIPBE306A Conduct

leaching process Acid leaching

PMAOPS208B Operate

chemical separation

equipment

PMAOPS302B Operate


equipment

This is close but not quite

right

Packaging

PMAOPS213B Package

product/material

Aimed a packaging fluids

Truck loading

The process by unit of competency SR to TiO2

RII09 unit Process step PMA08 unit Comment RIIPEO201A Conduct

conveyor operations Silo to process –

conveyor belt, weigh

feeder

PMAOPS210B Operate


equipment

PMAOPS309B Operate


storage equipment

Chlorination – fluidised

bed reactor

PMAOPS302B Operate


equipment

This unit doesn’t really

cover fluidised beds

Purification – acid wash

PMAOPS208B Operate

chemical separation

equipment

This probably works, but

was not written for this

application

Oxidation – TiO2

formation

PMAOPS302B Operate


equipment

PMAOPS303B Operate


Recovery – acid wash

PMAOPS208B Operate

chemical separation

equipment

This probably works, but

was not written for this

application

RIIPHA301A Conduct

milling/grinding Milling

PMAOPS217B Operate wet

milling equipment

RIIPRO202A Conduct


operations Grading

Coating

Drying – fluidised bed

Filtering – bag house

PMAOPS206B Operate


PMAOPS232B Produce

Neither of these really cover

a bag house operation



RII09 unit Process step PMA08 unit Comment product by filtration

Agglomerate

breakdown (steam)

Packaging

PMAOPS213B Package

product/material

Truck loading

Uranium (U)

Mineral source

The major mineral sources in Australia are uraninite (UO2), pitchblende (a

mixed oxide, usually U3O8), brannerite (a complex oxide of uranium, rare-

earths, iron and titanium) and coffinite (uranium silicate). Pitchblende is the

most commonly used ore.

One of the largest producers (Olympic Dam) produce U as a by-product of Cu.

Product(s)

Uranium is used because it is naturally radioactive. Its major peaceful uses

therefore are for power generation and the making of radioisotopes.

It is mainly used therefore as 235

U as an oxide.


U is mined either using mechanical means or by acid or alkaline leaching. At

Olympic Dam it is mined along with copper ore.

Where it is mined by mechanical means, the ore is first crushed and ground and

it is then acid or alkali leached to recover the U. Tailings are settled out and the

liquor filtered to remove remaining solid contamination. The U is then

recovered using solvent extraction, ion exchange or precipitation. Olympic dam

use NH3 to precipitate yellow cake ((NH4)2U2O7). This is then be heated to

~700oC which increases the concentration to ~ 98% U3O8 and it is a dark grey-

green colour. It is usually exported in this form.

U metal is not made in Australia


RII09 unit Process step PMA08 unit Comment RIIPRO201A Conduct

crushing operations

RIIPHA301A Conduct

milling/grinding


PMC552008B Operate

crushing equipment

PMC552003C Operate

grinding equipment



RII09 unit Process step PMA08 unit Comment RIIPBE310A - Conduct

flotation process Froth flotation

RIIPBE306A Conduct

leaching process Leaching

PMAOPS220B Monitor


process

PMAOPS302B Operate


equipment

These don’t really cover

leaching.

Settling

PMAOPS206B Operate


RIIPBE303A Conduct

filtering process



Filtration

PMAOPS232B Produce


RIIPBE203A Conduct

precipitation operations Precipitation

PMAOPS220B Monitor


process

PMAOPS302B Operate


equipment

Heating PMAOPS323A Operate and


Zinc (Zn)

Mineral source

The major mineral sources in Australia are sphalerite (Zn,FeS), smithsonite

(ZnCO3), willemite (Zn2(SiO4)) and hemimorphite (Zn4Si2O7(OH)2·H2O).

In Australia Zn is often found with Pb and Ag (eg Broken Hill) and Pb, Ag and

Cu (Mt Isa).

Product(s)

Zn is widely used as a metal for galvanising, die casting and as an alloy with Cu

to make brass.

Zn is also used as ZnO as an additive to polymers and to make zinc cream both

as a sunscreen and a nappy cream.

Zn, ZnO and various Zn salts have various uses in the chemical industry.


Zinc sulphide concentrates (mainly ZnS with some FeS2 and PbS) are unloaded

at the wharf and then transported to hoppers for conveying to the roasting

process. This concentrate will have been produced by crushing the ore and then

concentrating it using flotation.

Roasting



The roaster is a fluidised bed and as this is an exothermic reaction (above

800oC) needs to be cooled to prevent runaway and sintering of the product

(>1000oC). The product is a calcine, consisting mainly of ZnO

2ZnS + 3O2 2ZnO + 2SO2 +

2FeS + ZnS + 5O2 ZnO.Fe2O3 + 3SO2

PbS + 2O2 PbSO4

The heat from this process is used to raise steam in a waste heat boiler. The

steam is used to generate power and to provide heat to the leach process. If the

roasters are off line, or for start up, oil fired package boilers are used to raise

steam. The waste gas is cleaned using cyclones and an electrostatic precipitator

which remove calcine dust. The calcine is cooled using drum coolers

The SO2 produced in the roasting is drawn off, cleaned and converted to SO3

using the contact process before being absorbed into concentrated H2SO4 to

make a more concentrated H2SO4.

2SO2 + O2 2SO3 +

SO3 + H2O H2SO4 +

The cleaning process requires first cooling, then scrubbing through a packed

tower followed by further electrostatic precipitation (to remove SO3 fume) and

then a Boliden-Norzink Mercury process to remove traces of Hg. The SO2 is

then dried by scrubbing with 96% H2SO4 before being fed to the catalytic

converter.

The SO3 produced is absorbed into 98.6% H2SO4. The remaining tail gas is

scrubbed with water to produce a clean tail gas.

Leaching

The purpose of the leaching is to convert the ZnO (calcine) into a ZnSO4

solution. It is a five stage, counter current process using spent electrolyte

(H2SO4) as the solvent. Acid strength and temperature are varied over the five

stages to optimise the removal of Zn. Each stage has a stirred tank reactor for

the dissolution with a thickener to separate the slurry from the solution. The

slurry will go to a more aggressive leaching stage. There is a residual solid

Ag/Pb stream which is sent to Port Pirie for further processing. Spent electrolyte

from the electrolysis stage is the major liquid stream (solvent). There is also

filtration on slurry streams which leave the plant to increase the concentration of

solids leaving the plant. The reactions which occur depend on the stage of the

leach with the major ones being summarised:

ZnO + H2SO4 ZnSO4 + H2O

ZnSiO4 + 2 H2SO4 ZnSO4 + SiO2 2H2O

ZnO.Fe2O3 + 4H2SO4 ZnSO4 + Fe2(SO4)3 + 4H2O



Fe2(SO4)3 + 4H2O 2FeO.OH + 3H2SO4

There is a wider range of reactions than these.

Paragoethite is also precipitated from the leach stage and recovered using a

thickener.

Fe2(SO4)3 + 4H2O 2FeO.OH + 3H2SO4

The sludge is then filtered through a plate and frame filter press before being

dried in a fired rotary kiln where it is also mixed with lime. The Paragoethite is

sent to Port Pirie for further processing.

Effluent treatment is also part of this process. Liquid streams are treated for

reuse where possible or for disposal as waste. Lime neutralisation is used to

precipitate metals and mercury is also removed using a packed bed containing

Al pellets which adsorb the Hg.

ZnSO4 + Ca(OH)2 +2H2O Zn(OH)2 + CaSO4.2H2O

Purification

The leaching process also causes other metals to dissolve and so are in solution

with the Zn. These are removed in a two stage purification process, the Primary

Purification removing Cu and the Secondary Purification removing Cd, Ni, and

Co. Both stages occur by adding Zn dust which displaces the less active metals

from solution. There is the possibility of also forming H2 gas and so the process

occurs under a N2 blanket to avoid explosive mixtures of H2 and O2.

Primary Purification sees the incoming stream heated to 86oC using spiral heat

exchangers before adding the Zn dust slurry to stirred reactors (four in series).

The Cu cementate is filtered off using a plate and frame filter press. This is then

leached using dilute H2SO4 to produce CuSO4 which is separated from insoluble

solids using a leaf filter. CuSO4 is then crystallised, separated by centrifuge

from the liquor, dried in a heated rotary drier and then bagged for sale.

The filtrate from, the primary purification is dosed with leaded zinc dust mixed

with potassium antinomy tartrate to assist Co removal. This is done in six stirred

reactors in series. The precipitate is recovered by filtration. The filter cake is

releached to recover Zn and subsequently Cd. The leached filter cake is sold as

a source of Co, Ni and Pb to a third party.

Electrolysis

Warm solution from Secondary Purification is cooled to remove the dissolved

gypsum (CaSO4) from solution. Gypsum seed crystals are added and the

gypsum settled out in a thickener. The clarified overflow is sent to electrolysis.

Al cathodes and Pb anodes are used. The Zn plates onto the cathode with some

H2 also being formed (`10% of electricity is consumed this way). O2 is liberated

at the anode and reacts with Mn2+

in solution to form MnO2 which forms as a

mud/scale. The units are laid out with cells in series, cascading from one to the



other. The final spent electrolyte is recycled to the leaching process. Cells are

cooled.

ZnSO4 + 2H2O 2Zn + 2H2SO4 + O2

Cathode sheets are periodically removed and mechanically stripped of their Zn.

Casting

The stripped Zn is charged to an induction furnace for melting. Once molten

dross is periodically removed. It is then pumped to launders from where it is

delivered to a casting machine, block moulds or to alloying furnaces.


RII09 unit Process step PMA08/PMC10 unit Comment RIIPSM304A Operate

furnaces Roasting furnace

PMAOPS303B Operate



calcining kiln

Contact acid catalytic

conversion

PMAOPS302B Operate


equipment

Absorption (packed

tower)

PMAOPS208B Operate

chemical separation

equipment

Leaching (stirred tank

reactors)

PMAOPS220B Monitor


process

Thickeners

PMAOPS206B Operate


Filtration (plate and

frame)

PMAOPS206B Operate


PMAOPS232B Produce


Fired rotary kiln dryer



Purification (stirred

reactors)

PMAOPS220B Monitor


process

Crystallisers

Centrifugal separation

PMAOPS207B Operate

powered separation

equipment

Electrolysis

PMASMELT264B Start up

reduction cells


reduction cells

PMASMELT269A Operate

cell tending equipment

These are currently specific

to Al.

Anode stripping




Zn melting furnace

MEM04001A Operate

melting furnaces


Launders

MEM13004A Work safely

with molten metals/glass

MEM04007A Pour molten

metal


molten metal

SMELT266 is currently

specific to Al.

Alloying

RIIPSM302A Cast ingots

Casting

PMASMELT267B Cast

aluminium ingots

This is currently specific to

Al.


Waste heat boiler

Power station



boiler

PMAOPS325B Generate

electrical power


treat water system Settling dam

PMAOPS206B Operate


Cyclones

PMAOPS206B Operate


RIIPBE305A: Conduct high

tension separation Electrostatic

precipitators

Heat exchange

PMAOPS205B Operate heat

exchangers

Scrubbing

PMAOPS208B Operate

chemical separation

equipment

Lime neutralisation

PMAOPS220B Monitor


process

Metalliferous minerals processing scoping project - MSA · Silver (Ag ... Refining Cast Transport...

Documents

Transcript of Metalliferous minerals processing scoping project - MSA · Silver (Ag ... Refining Cast Transport...