Download Environmental Studies

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
Environmental Implications of
Bauxite Mining in Jamaica
Extraction
- Mining involves deforestation
Removal of top soil
- Noise pollution
- Dust pollution
Environmental Implications of
Bauxite Mining in Jamaica Cont’d
Deforestation
- Habitat
destruction
- Soil erosion
- Sedimentation of rivers
- Smothering of aquatic habitats
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
Processing Bauxite
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.
Environmental Implications of
Bauxite Mining in Jamaica Cont’d
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
Bauxite Mining in Jamaica Cont’d
Legislation
-
NRCA Air Quality Regulations 2002.
Companies apply for permit to emit air pollutants
Yearly reports to NEPA
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
Cooking & Lighting
Other
Bauxite/Alumina
Processing
Electricity Generation
Aviation
Bauxite/Alumina
Processing
Road and Rail Transport
Aviation
Road and Rail Transport
Cooking & Lighting
Other
Electricity Generation
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
Alternate Energy Sources
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.
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
Alternate Energy Sources
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
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
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
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 Management
Solid 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
Disadvantages
• Not a solution to the
garbage going to landfills throwaway society
• Saves energy
• Takes energy to recycle
materials
• Reduces pollution
• 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.