Lecture 8

Energy and Minerals

                               

Mineral

- A mineral is any naturally occurring inorganic substance or element found in the Earth’s crust

- The word rock refers to solid mineral deposits

- An ore is rock that contains a large proportion of a particular mineral, making it profitable for mining or extraction.

Formation of Rocks

Rocks are classified based on their method of formation:

1. Igneous rocks are formed due to intense heat and are associated with volcanic activity

2. Sedimentary rocks are formed by settling and fusing of sediments

3. Metamorphic rocks are formed by transformation due to pressure, heat and water.

Types of minerals

- Metals are minerals e.g. iron, aluminium and copper, which are malleable, lustrous and good conductors of heat and electricity.

- Non-metallic minerals lack these characteristics e.g. sand, stone, salt and phosphates.

Uses of Minerals

- many can be extracted & converted into useful materials

For example:

- aluminium is used to make cars & airplanes

- steel is an essential building material

- copper is used for electrical & communication wiring

- sulfur is used to make plastics & refine oil

Mineral

- Mineral resources are deposits of minerals in such quantities and of a particular grade that there are reasonable prospects for economic extraction.

- Mineral reserves are mineral deposits that are profitable to extract

- A country’s mineral reserves is only a part of its total mineral resources

Jamaica’s Bauxite Resources

Total Reserves estimated at 2 billion tons

Mining

- the various processes whereby minerals are extracted

The 2 main types of mining are:

• Sub-surface Mining

• Surface Mining

Mining

• Sub-surface Mining- extraction of a metal ore or fuel resource

from a deep underground deposit

• Surface Mining- removal of soil before extracting a

mineral deposit found fairly close to the earth’s surface

Mining

Overburden

- layer of soil and rock overlying mineral deposit

- removed during surface mining

Types of Surface Mining

• Open-pit mining

• Dredging

• Strip mining

Types of Surface Mining

Open-pit Mining

- machines dig holes and remove ores, e.g., iron, copper, bauxite

Types of Surface Mining

• Dredging

- chain buckets and draglines scrape up underwater mineral deposits

Types of Surface Mining

• Strip Mining

- surface mining in which bulldozers, power shovels, or stripping wheels remove the

overburden in strips

- used mostly for removing coal and some phosphate rock

Types of Sub-surface Mining

• Shaft Mine

• Slope Mine

Types of Sub-surface Mining

• Shaft Mine

- a direct vertical shaft to the vein of the ore

- the ore is broken up underground, then hoisted through the shaft through the surface in buckets

Types of Sub-surface Mining

• Slope Mine

- has a slanting passage that makes it possible to haul the broken ore out of the mine in cars

Extraction

   - Mining involves deforestation

Removal of top soil

- Noise pollution

- Dust pollution

Environmental Implications of

Bauxite Mining in Jamaica

Deforestation

- Habitat destruction

- Soil erosion

- Sedimentation of rivers

- Smothering of aquatic habitats

Environmental Implications of

Bauxite Mining in Jamaica Cont’d

Legislation

- Mining Act of 1947.

Top soil should be removed before mining and restored as part of the reclamation process

Soil less capable of retaining water. Only tree crops and pasture feasible

Bauxite Mining in Jamaica Cont’d

This involves smelting – melting the ore at high temperatures to help separate impurities from the molten metal.

If air pollution control devices are not installed, many dangerous gases are emitted during smelting.

Processing Bauxite

Processing

- Processing and disposal of minerals pollute the air, soil and water.

- Rio Cobre polluted to the point where fish kills observed

- Air pollution implicated in roof damage, fence damage

Environmental Implications of

Bauxite Mining in Jamaica Cont’d

Bauxite and Alumina dust

- Causes respiratory problems

- Affects coral reefs due to spillage at ports

- Defaces property

Environmental Implications of

Bauxite Mining in Jamaica Cont’d

Solutions

- Construct marshes or ponds downstream from mines.

- When a mine is abandoned, the land can be reclaimed, or restored to semi-natural conditions

- New disposal method for red mud

- Install pollution control devices to smelters

Environmental Implications of

Bauxite Mining in Jamaica Cont’d

Legislation

- NRCA Air Quality Regulations 2002.

Companies apply for permit to emit air pollutants

Yearly reports to NEPA

Bauxite Mining in Jamaica Cont’d

Fossil Fuel

- Product of partial or complete decomposition of plants and animals that occur as crude oil, coal, natural gas, or heavy oils

- Formed as a result of exposure to heat and pressure in the earth’s crust over millions of years

- non-renewable, exhaustible resource

PETROLEUM CONSUMPTION BY ACTIVITY

Bauxite/Alumina Processing

Electricity Generation

Road and Rail Transport

Aviation

Cooking & LightingOther

Bauxite/AluminaProcessing

Electricity Generation

Road and Rail Transport

Aviation

Cooking & Lighting

Other

Fossil Fuel

LNG (Liquid Natural Gas)

- Natural gas is 90% methane

- LNG is easier to store and transport

- Landfills are a renewable source

- Environmentally friendly

(Less sulphur and nitrogen compounds and ash)

Nuclear Energy

- energy released when atomic nuclei undergo a nuclear reaction, such as nuclear fission or nuclear fusion

                                                                                                                       

       

Nuclear Energy cont’d

Nuclear Fission

- nuclear change in which the nuclei of atoms are split apart

- releases a large amount of energy

Nuclear Energy cont’d

Nuclear Fusion

- nuclear change in which two nuclei are forced together

- releases a large amount of energy

Nuclear Power & the Caribbean

- as small nuclear plants become more efficient and more cost-effective, this source of power could be considered an option for larger Caribbean countries

- construction was halted on Cuba’s nuclear plant

- nuclear power could economically give optimal value to Jamaican bauxite

Renewable energy sources are sources of energy that are replenished by natural processes so that they can be used indefinitely. They include:

Direct Solar Energy, Wind Energy, Hydropower, Ocean Thermal Energy, Geothermal Energy and Tidal Energy.

Alternate Energy Sources

Geothermal Energy

- heat contained in underground rocks and fluids

- heat transferred from the earth’s underground concentrations of dry steam, wet steam, or hot water trapped in rock

- wells can be drilled to extract the steam or water

- ~ 20 countries using geothermal energy

Geothermal Energy & Caribbean States

- utilised for power production in Guadeloupe

- many Caribbean islands, e.g., St Lucia, Dominica, Montserrat, have potential

- 35 hot springs identified in Jamaica

- investment risks for geothermal exploration in developing countries is considered high

Renewable energy sources account for only 4% of energy mix.

- Projected to reach 12% by 2020

- Wigton wind farm commissioned in May 2004

23 wind turbines of 20.7 MW capacity avg 7 MW

Alternate Energy Sources

Solar Energy

- considered a renewable resource

- direct radiant energy from the sun and a number of indirect forms of energy produced by the direct input

Solar Energy & Caribbean States

- ~ 3,500 solar water heaters installed in Jamaica (2002)

- ~ 34,000 solar water heaters installed in Barbados (2002)

- economic incentives should be provided to increase solar power use

- all water heaters should be solar

Energy conservation is moderating or eliminating wasteful or unnecessary energy-consuming activities.

Energy efficiency is using technology to accomplish a particular task with less energy.

Energy Conservation

Energy Conservation

Energy Conservation

To calculate energy use for appliances use the following equation:

Wattage Hrs Used per Day = Daily KWh consumption               1000

(1 kilowatt (kW) = 1,000 Watts)

National Energy Policy

– The application of new technologies such as a cycle gas turbine.

– Renewable energy production of electricity supplies should be increased from about 5% to 15 % by 2012.

– Expansion of higher cost energy efficiency measures, such as solar water heaters and photovoltaic solutions.

– The provision of increased tax incentives so as to ensure higher investments in energy efficiency.

National Energy Policy Cont’d

– NHT has the authority to introduce loans to improve solar water heater and photovoltaic systems

– Tourism as one of the pillars of the economy. – The formulation of higher environmental

standards by Petrojam. – The new coal plant is to incorporate clean

coal technologies.

Waste ManagementSolid Waste

- Any unwanted or discarded material that is not a liquid or a gas

- It is estimated that approximately 1 billion tonnes of waste is generated across the island annually.

- 70% collected

- Half is generated in the Riverton wasteshed.

Types of Solid Waste

• Municipal Solid Waste- solid materials discarded by homes and

businesses in or near urban areas

• Non-municipal Waste- includes waste from mining, agriculture,

industry

There are 4 ways to get rid of solid wastes:

• dump

• bury

• burn

• recycle

Open Dumps

- unsanitary

- malodorous

- methane gas released as wastes decompose

- fire pollutes air with acrid smoke

- hazardous wastes leach into groundwater

Sanitary Landfills

- wastes are spread out in thin layers, compacted and covered daily

- lined with clay and plastic before being filled with garbage

- open burning is disallowed

- methane gas is collected and burned to produce steam or electricity

Sanitary Landfills cont’d

-

Incineration

- kills germs

- reduces the volume of waste going into landfills by ~ 60%

- puts toxic substances into the atmosphere

- the amount of material to be buried is greatly reduced but its toxicity is increased

Recycling

- collecting and reprocessing a resource so that it can be made into new products

Composting

Compost

- a sweet-smelling, dark-brown humus that is rich in organic matter and soil nutrients

- produced by mixing biodegradable solid waste with soil

                                                

Recycling in the Caribbean cont’d

Advantages

• Reduces the amount of garbage going to landfills

• Saves energy

• Reduces pollution

Disadvantages

• Not a solution to the throwaway society

• Takes energy to recycle materials

• Only puts a small dent in the solid waste problem

Legislation

The National Solid Waste Management Act was passed in 2001.

- The National Solid Waste Management Authority was established in April 2002.

- The public cleanliness regulations were drafted and gazetted in 2003.

Legislation- The penalty for throwing, dropping or otherwise

depositing and leaving any litter in any public place is $2,000

- The penalty for willfully breaking any bottle or any glass or any article made of glass in, or, on any public place without lawful authority is $5,000

- The penalty for employing or recruiting person(s) who erect, display, deposit or affix anything in a public place or on any building, wall, fence or structure is $10,000.