4. • A naturally occurring inorganic
solid with a defined chemical
composition and crystal structure
(regular arrangement of atoms).
• Minerals are the ingredients
of rock
Mineral
5. Ore
• Ore is rock with an enrichment of minerals that can be mined for
profit.
Ore
deposits
• Locations with abundant ore
Enrichment
factor
• The ratio of the metal concentration needed for an economic ore
deposit over the average abundance of that metal in Earth’s crust
6. Mining and
Processing Ore
There are two
kinds of mineral
mines
Surface
mines
Underground
mines
The kind of mine used depends on the quality of the ore,
i.e., concentration of mineral and its distance from the
surface.
7. Surface
mines
Open-pit mines
which commonly involve large holes that
extract relatively low-grade metallic ore
Strip mines which extract horizontal layers of ore or
rock
Placer mines
where gold or diamonds are extracted
from river and beach sediment by
scooping up (dredging) the sediment and
then separating the ore by density.
Large, open-pit mines can create huge piles of rock (called overburden) that was
removed to expose the ore as well as huge piles of ore for processing.
8. • which are used when
relatively high-grade ore is
too deep for surface mining
• involve a network of tunnels
to access and extract the ore.
Underground
mines
9. Processing metallic ore (e.g., gold, silver, iron, copper,
zinc, nickel, and lead) can involve numerous steps
• Crushing
• Grinding with water
• Physically separating the ore minerals from non-ore minerals often
by density
• Chemically separating the metal from the ore minerals using methods
such as
• Smelting (heating the ore minerals with different chemicals to
extract the metal)
• Leaching (using chemicals to dissolve the metal from a large
volume of crushed rock).
10. • The fine-grained waste produced from
processing ore is called tailings.
Tailings
• Slag is the glassy unwanted by-
product of smelting ore.
Slag
Many of the nonmetallic minerals and rocks do not require chemical
separation techniques.
11. Open Pit Mine Bingham Canyon copper mine in Utah, USA. At 4 km wide and 1.2 km deep, it
is the world’s deepest open-pit mine. It began operations in 1906.
12. Mineral Resources and Sustainability Issues
• How to cope with finite supplies?
• How to mitigate the enormous environmental impacts
of mining and processing ore?
• As global population growth continues demand for
products made from minerals will increase?
• We are depleting our known mineral deposits at an
increasing rate.
• New deposits should be found and put into production.
13. Sustainable Solutions to the Mineral
Crisis?
• The general approach towards mineral sustainability
should include:
• Mineral conservation at the top of the list.
• Maximize exploration for new mineral resources
• Minimize the environmental impact of mineral
mining and processing.
15. Improved efficiency applies to all features of
mineral use including mining, processing, and
creation of mineral products.
Substituting a rare nonrenewable resource with
either a more abundant nonrenewable resource or a
renewable resource can help.
• Examples include substituting glass fiber optic cables for copper
in telephone wires and wood for aluminum in construction.
16. Reducing the demand
• Technology can help some with some avenues to
reducing mineral consumption.
• For example, digital cameras have virtually
eliminated the photographic demand for silver,
which is used for film development.
• Using stronger and more durable alloys of steel can
translate to fewer construction materials needed.
17. Reuse
• Examples of natural resource reuse include everything at an
antique store and yard sale.
Recycle
• Recycling can extend the lifetime of mineral reserves,
especially metals.
• Recycling is easiest for pure metals such as copper pipes and
aluminum cans, but much harder for alloys (mixtures of
metals) and complex manufactured goods, such as computers.
18. Recycling (conti…..)
• Many nonmetals cannot be recycled;
examples include road salt and fertilizer.
• Recycling is easier for a wealthy country
because there are more financial resources to
use for recycling and more goods to recycle.
19. Additional significant benefits of mineral
resource conservation are:
• Less pollution
• Less environmental degradation from new mineral
mining and processing
• Reductions in energy use
• Reduction in waste production
20. Sustainable solutions to
metal extraction
Biooxidation
microbial enrichment of
metals in a solid phase
Bioleaching
microbial dissolution of
metals
Biosorption
attachment of metals to
cells
Genetic engineering of
microbes
creating microorganisms
specialized in extracting
metal from ore
21. References
• Clugston, C. (2010) Increasing Global
Nonrenewable Natural Resource Scarcity - An
Analysis, The Oil Drum. Retrieved
from http://www.theoildrum.com/node/6345
• Craig J, Vaughan D, and Skinner B (2011) Earth
Resources and the Environment (4th ed.). Pearson
Prentice Hall, p. 92