energy minerals and waste management

8/11/2019 Energy Minerals and Waste Management

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Lecture 8

Energy and Minerals
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Mineral

- A mineral is any naturally occurring inorganicsubstance or element found in the Earths 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 miningor extraction.
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Formation of Rocks

Rocks are classified based on their method offormation:

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

2. Sedimentary rocks are formed by settling and fusingof sediments3. Metamorphic rocks are formed by transformation due

to pressure, heat and water.


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Types of minerals

- Metals are minerals e.g. iron, aluminiumand 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 .


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Uses of Minerals

- many can be extracted & converted into usefulmaterials

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


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Mineral

- Mineral resources are deposits of minerals in suchquantities and of a particular grade that there arereasonable prospects for economic extraction.

- Mineral reserves are mineral deposits that are profitable to extract

- A countrys mineral reserves is only a part of itstotal mineral resources


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Jamaicas Bauxite Resources

Total Reserves estimated at 2 billion tons


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Mining

- the various processes whereby minerals areextracted

The 2 main types of mining are:

Sub- surface Mining Surface Mining


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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 earths surface


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Mining

Overburden- layer of soil and rock overlying mineral deposit

- removed during surface mining


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Types of Surface Mining

Open-pit mining

Dredging

Strip mining


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Open-pit Mining- machines dig holes and remove ores , e.g., iron,

copper, bauxite


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Dredging- chain buckets and draglines scrape upunderwater mineral deposits


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Strip Mining- surface mining in which bulldozers, powershovels, or stripping wheels remove the overburden in strips

- used mostly for removing coal and somephosphate rock


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Types of Sub-surface Mining

Shaft Mine

Slope Mine


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Shaft Mine- a direct vertical shaft to the vein of the ore

- the ore is broken up underground, thenhoisted through the shaft through the surface in

buckets


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Slope Mine- has a slanting passage that makes it possibleto haul the broken ore out of the mine in cars


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Extraction

- Mining involves deforestation

Removal of top soil

- Noise pollution

- Dust pollution

Environmental Implications of

Bauxite Mining in Jamaica


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Deforestation

- Habitat destruction

- Soil erosion

- Sedimentation of rivers

- Smothering of aquatic habitats


Bauxite Mining in Jamaica Contd


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Legislation

- Mining Act of 1947.

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

Soil less capable of retaining water. Only tree cropsand pasture feasible



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This involves smelting melting theore at high temperatures to help

separate impurities from the moltenmetal.

If air pollution control devices are notinstalled, many dangerous gases areemitted during smelting.

Processing Bauxite


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Processing

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

- Rio Cobre polluted to the point where fishkills observed

- Air pollution implicated in roof damage,fence damage




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Bauxite and Alumina dust

- Causes respiratory problems

- Affects coral reefs due to spillage at ports

- Defaces property




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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




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Legislation

- NRCA Air Quality Regulations 2002.

Companies apply for permit to emit air pollutants

Yearly reports to NEPA



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Fossil Fuel

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

- Formed as a result of exposure to heat andpressure in the earths crust over millions of years

- non-renewable, exhaustible resource


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PETROLEUM CONSUMPTION BY ACTIVITY

Bauxite/AluminaProcessing

Electricity Generation

Road and Rail Transport

Aviation

Cooking & LightingOther

Bauxite/AluminaProcessing

Electricity Generation

Road and Rail Transport

Aviation

Cooking & Lighting

Other


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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)


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Nuclear Energy

- energy released when atomic nuclei undergo anuclear reaction, such as nuclear fission ornuclear fusion


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Nuclear Energy contd

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

- releases a large amount of energy


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Nuclear Energy contd

Nuclear Fusion- nuclear change in which two nuclei are forcedtogether

- releases a large amount of energy


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Nuclear Power & the Caribbean

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

Caribbean countries

- construction was halted on Cubas nuclear plant

- nuclear power could economically give optimalvalue to Jamaican bauxite


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Geothermal Energy

- heat contained in underground rocks and fluids

- heat transferred from the earths undergroundconcentrations of dry steam , wet steam , or hotwater trapped in rock

- wells can be drilled to extract the steam or water

- ~ 20 countries using geothermal energy


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Renewable energy sources account for only 4% ofenergy 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


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Solar Energy

- considered a renewable resource

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


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Solar Energy & Caribbean States

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

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

- economic incentives should be provided toincrease solar power use

- all water heaters should be solar


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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


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Energy Conservation

To calculate energy use for appliances use the followingequation:

Wattage Hrs Used per Day = Daily KWh consumption1000

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


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National Energy Policy

The application of new technologies such as a cyclegas turbine.

Renewable energy production of electricity suppliesshould be increased from about 5% to 15 % by2012.

Expansion of higher cost energy efficiencymeasures, such as solar water heaters and

photovoltaic solutions. The provision of increased tax incentives so as to

ensure higher investments in energy efficiency.


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National Energy Policy Contd

NHT has the authority to introduce loans toimprove 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.


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Waste ManagementSolid Waste

- Any unwanted or discarded material that isnot a liquid or a gas

- It is estimated that approximately 1 billiontonnes of waste is generated across the islandannually.

- 70% collected

- Half is generated in the Riverton wasteshed.


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Types of Solid Waste

Municipal Solid Waste- solid materials discarded by homes andbusinesses in or near urban areas

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


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There are 4 ways to get rid of solid wastes:

dump

bury

burn

recycle


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Open Dumps

- unsanitary

- malodorous

- methane gas released as wastes decompose

- fire pollutes air with acrid smoke

- hazardous wastes leach into groundwater


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Sanitary Landfills

- wastes are spread out in thin layers, compactedand covered daily

- lined with clay and plastic before being filledwith garbage

- open burning is disallowed

- methane gas is collected and burned to produce

steam or electricity


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Sanitary Landfills contd

-


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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 greatlyreduced but its toxicity is increased


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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


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Recycling in the Caribbean contd

Advantages

Reduces the amount of

garbage going to landfills

Saves energy

Reduces pollution

Disadvantages

Not a solution to the

throwaway society

Takes energy to recyclematerials

Only puts a small dent inthe solid waste problem


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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 anyglass 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 orstructure is $10,000.

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