1. Mineral Resources

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1. Mineral Resources

• Environmental Studies - Unit 2
• Lesson 1

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Objectives

• To know the structure of the Earth
• To be able to list minerals that can be extracted
  from the Earths Crust.
• To recap the rock cycle

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The Earth
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Resources from the Earth

• There are a variety of natural resources taken
  from the Earths Crust including.
• Fossil Fuels
• Metals
• Non Metal Materials

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Rock Cycle
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Sedimentary Processes
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Alluvial / Placer Deposit
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Evaporites
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Biological Deposits

• Chalks and limestone are formed from the Calcium
  carbonate shells of organims
• Fossil fuels are formed from the build up of
  organic matter, compressed in anerobic conditions.

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Chemical Precipitation

• Manganese Nodule

Formed by the precipitation of the substance from
sea water. This is a very slow process taking
millions of years.
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Metamorphic Rock
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Intrusive Igneous - Batholiths
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2. Mineral Resources

• Environmental Studies Unit 2
• Lesson 2

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What do you know about the following???

• Oil
• Iron
• Aluminium
• Diamond

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Gold Prices
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Other Metals
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BHP Share Price
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Resources, reserves and Exploitation

• Minerals are non-renewable resources because the
  amounts that exist are finite although most are
  very abundant.
• Economically recoverable resources account for a
  tiny proportion of the total that exists.
• The main limitations on mineral availability are
  the locations, chemical form and purity of the
  deposits, and the availability of technologies to
  exploit them.
• Their exploitation is economically important but
  can cause environmental damage.

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Lead Ore
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Resources and Reserves

• Resources include all the material which is
  theoretically available for exploitation.
• This includes deposits that cannot be exploited
  now. eg too deep, low grade, unusable chemical
  form, prohibitive land use conflict
• Reserves include that portion of the resource
  which can be exploited now, economically, using
  existing technology.
• The size of a resource is finite but the quantity
  included in the reserves can change.
• eg the reserves will increase if there is an
  increase in market price or if new extraction
  technologies are developed. If market prices drop
  then reserves may decrease.

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Sources and Demand

• Factors affecting the viability of exploiting
  mineral deposits
• Extraction costs
• Affected by depth, overburden quality, drainage
  problems, size of deposit.
• Processing costs
• The cost of extracting a metal depends upon the
  other elements with which it is combined.
• eg aluminium is most abundant in clay but can
  only be economically extracted from bauxite
• Purity
• The financial cost, energy required and quantity
  of ore-bearing rock extracted all increase
  rapidly as ore purity decreases.

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• Factors affecting the viability of exploiting
  mineral deposits
• Land conflicts
• Competing land uses may be considered more
  important or valuable than mining. E.g. urban
  areas, conservation of landscape or wildlife.

• Transport costs
• These are affected by the distance to market, the
  ease of bulk transport and the presence of a
  suitable existing transport infrastructure.

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Factors affecting the viability of exploiting
mineral deposits

• Market economics
• The market demand and sale value of the minerals
  control the economic viability of exploiting a
  particular mineral deposit.
• The cut-off ore grade is the lowest ore purity
  that can be exploited economically.

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Mineral Resources

• Environmental Studies Unit 2
• Lesson 3

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The Environmental Impact of Mineral Exploitation

• Exploration, extraction and processing all cause
  significant environmental damage. A range of
  methods may be used to reduce these.
• www.goodquarry.com

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Exploration

• Marine seismic surveys affects whales.
• Exploration on land causes vegetation loss.

http//www.smh.com.au/news/whale-watch/blue-whales
-face-seismic-upset-when-feeding/2008/01/08/119955
4655598.html
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Land take
Extraction may cause conflicts with existing land
uses.

• Minerals can only be exploited where they are
  found. This makes land use conflicts more likely
  as there is a limited choice of locations that
  can be exploited.

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Habitat loss

• The loss of the species where the mineral is to
  be extracted is unavoidable.
• Removing the wildlife by capturing the animals
  and transplanting the plants to move them to
  unthreatened habitats has been attempted but is
  rarely completely successful.
• Habitat restoration when mining has ended is
  often carried out.

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Loss of Amenity

• Mining may cause aesthetic problems for local
  communities.

This may be reduced by landscaping and tree
planting.
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Air Pollution

• Dust, reduced by water sprays.

Noise, reduced by baffle mounds and restricted
times for blasting.
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Water Pollution

• Turbid drainage water, reduced by sedimentation
  lagoons and filtration.
• Toxic leachate, reduced by chemical treatment.

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Spoil Disposal

• Spoil instability can cause landslides or
  erosion.
• It can be reduced by drainage, compaction and
  landscaping.

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Transport nuisance

• Mineral transportation can produce noise, fumes,
  dust and cause traffic accidents.
• These can be reduced by water sprays and careful
  route choices.

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Flooding can be caused by drainage water

• The risk can be reduced by containment in lagoons
  behind well-constructed dams with carefully timed
  releases.

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Subsidence

• This is caused by poor spoil compaction or
  undermining.
• It can be reduced by compaction of spoil and
  leaving support pillars in deep mines

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Turbid Drainage Water

• Drainage water from mines or ore processing can
  smother aquatic plants and silt up rivers.
• This can be reduced by building sedimentation
  lagoons.

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Toxic Leachate

• Water draining from spoil heaps may contain toxic
  metals.
• This may be reduced by collection and chemical
  treatment.

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The Future of Mineral Supplies

• Environmental Studies Unit 2
• Lesson 4

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The future of Mineral Supplies

• Reserves of exploitable minerals are finite. They
  are non-renewable resources. A range of methods
  may be used to extend the time period in which
  they may be exploited.
• More exploration
• In previously unexplored areas, e.g. remote
  areas/areas with difficult conditions.
• eg Antarctic
• Deep ocean floor for manganese nodules

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Better Exploratory techniques

• Remote sensing
• eg Satellite surveys allow rapid aerial
  photography of large areas of land Geophysical
  techniques
• seismic surveys echoes of surface vibrations
  provide information on depth, angle, density and
  thickness of rock strata.
• Gravimetry the strength of gravity provides
  information on the density of rocks. Igneous
  rocks are usually more dense than sedimentary
  rocks.
• Magnetometry the strength of magnetism helps to
  detect magnetic rocks, eg iron ores.

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Better Mechanised Mining Techniques

• Better/more mechanised mining techniques
• eg larger excavators which can dig deeper into
  the ground

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Use of low-grade ores

• Electrolysis of spoil heap leachate to remove
  copper bacterial recovery from disused mine
  spoil

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Recycling

• to make used materials into a new resource.
• eg melting of scrap metals and glass
• crushing of used concrete

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Substitution

• The use of alternative more abundant materials.
• eg plastic pipes instead of copper
• fibre-optics instead of copper for
  telecommunications