Chapter 16Chapter 16Minerals: A Non-renewable ResourceMinerals: A Non-renewable Resource

Overview of Chapter 16Overview of Chapter 16

o Introduction to MineralsIntroduction to Minerals• Mineral Distribution and FormationMineral Distribution and Formation• How Minerals are Found and ExtractedHow Minerals are Found and Extracted

o Environmental Impact of MineralsEnvironmental Impact of Mineralso An International PerspectiveAn International Perspectiveo Increasing the Supply of MineralsIncreasing the Supply of Mineralso Substitution and ConservationSubstitution and Conservation

Introduction to MineralsIntroduction to Minerals

o MineralsMinerals• Elements or compounds of elements that Elements or compounds of elements that

occur naturally in Earth’s crustoccur naturally in Earth’s crust

o RocksRocks• Naturally formed aggregates of mineralsNaturally formed aggregates of minerals

o Examples of MineralsExamples of Minerals• Concrete (mixture of Concrete (mixture of

sand, gravel and sand, gravel and

limestone)limestone)

Introduction to MineralsIntroduction to Minerals

o Examples of MineralsExamples of Minerals• Table salt (nonmetal)Table salt (nonmetal)• Copper (metal)Copper (metal)

Mineral Distribution and Mineral Distribution and FormationFormation

o Abundant minerals in crustAbundant minerals in crust• Aluminum and ironAluminum and iron

o Scarce minerals in crustScarce minerals in crust• Copper, chromium, and molybdenumCopper, chromium, and molybdenum

o Distributed unevenly across globeDistributed unevenly across globe• If found in low abundance, mining is not If found in low abundance, mining is not

profitableprofitable

Formation of Mineral DepositsFormation of Mineral Deposits

o Result of natural processesResult of natural processes• Magmatic concentrationMagmatic concentration

• As magma cools heavier elements (Fe and Mg) As magma cools heavier elements (Fe and Mg) settlesettle

• Responsible for deposits of Fe, Cu, Ni, CrResponsible for deposits of Fe, Cu, Ni, Cr• Hydrothermal processesHydrothermal processes

• Minerals are carried and deposited by water Minerals are carried and deposited by water heated deep in earth’s crustheated deep in earth’s crust

• SedimentationSedimentation• Weathered particles are transported by water Weathered particles are transported by water

and deposited as sediment on sea floor or shoreand deposited as sediment on sea floor or shore• EvaporationEvaporation

• Salts are left behind after water body dries upSalts are left behind after water body dries up

Discovering Mineral DepositsDiscovering Mineral Deposits

o Scientists (geologists) use a variety of Scientists (geologists) use a variety of instruments and measurementsinstruments and measurements• Aerial or satellite photographyAerial or satellite photography• Aircraft and satellite instruments that Aircraft and satellite instruments that

measure Earth’s magnetic fieldmeasure Earth’s magnetic field• SeismographsSeismographs

o Combine this with knowledge of how Combine this with knowledge of how minerals are formedminerals are formed

Extracting MineralsExtracting Minerals

o Surface MiningSurface Mining• Mineral and energy resources are extracted Mineral and energy resources are extracted

near Earth’s surface by removing soil, near Earth’s surface by removing soil, subsoil and over-lying rock stratasubsoil and over-lying rock strata

• More common because less expensiveMore common because less expensive• Two kinds: open pit and strip miningTwo kinds: open pit and strip mining

o Subsurface MiningSubsurface Mining• Mineral and energy resources are extracted Mineral and energy resources are extracted

from deep underground depositsfrom deep underground deposits• Two kinds: shaft mine and slope mineTwo kinds: shaft mine and slope mine

Extracting Minerals-Extracting Minerals-Open Pit Surface MiningOpen Pit Surface Mining

Processing MineralsProcessing Minerals

o Smelting- Smelting- process in process in which ore is which ore is melted at high melted at high temps to temps to separate separate impurities from impurities from the molten the molten metalmetal

Environmental Impacts of Environmental Impacts of MineralsMinerals

o Disturbs large areaDisturbs large area• Prone to erosionProne to erosion

o Uses large quantities of waterUses large quantities of water• Must pump water out of mine to keep it dryMust pump water out of mine to keep it dry

o Acid Mine Drainage (AMD)Acid Mine Drainage (AMD)• Pollution caused when sulfuric acid and Pollution caused when sulfuric acid and

dissolved lead, arsenic or cadmium wash dissolved lead, arsenic or cadmium wash out of mines into nearby waterwaysout of mines into nearby waterways

Environmental Impacts of Refining Environmental Impacts of Refining MineralsMinerals

Environmental Impacts of Refining Environmental Impacts of Refining MineralsMinerals

o 80% or more of 80% or more of mined ore consists of mined ore consists of impurities- called impurities- called tailingstailings• Contain toxic materialsContain toxic materials

o Smelting plants emit Smelting plants emit large amounts of air large amounts of air pollutantspollutants

o Requires a lot of Requires a lot of energy (fossil fuels energy (fossil fuels combustion)combustion)

Case-In-Point Copper Basin, TNCase-In-Point Copper Basin, TN

Restoration of Mining LandsRestoration of Mining Landso Goals: prevent further degradation and Goals: prevent further degradation and

erosion of land, eliminate local sources erosion of land, eliminate local sources of toxins and make land productive for of toxins and make land productive for another purposeanother purpose

Restoration of Mining LandRestoration of Mining Land

o Creative ApproachesCreative Approacheso - Wetlands- Wetlands

• Trap sediment and pollutants before they Trap sediment and pollutants before they get into streams, improving water qualityget into streams, improving water quality

• Expensive to create and maintain, but cost Expensive to create and maintain, but cost effective compared to using lime to effective compared to using lime to decrease aciditydecrease acidity

o - Phytoremediation- Phytoremediation• Use of specific plants to absorb and Use of specific plants to absorb and

accumulate toxic materials in soilaccumulate toxic materials in soil• Great potentialGreat potential

Minerals: An International Minerals: An International PerspectivePerspective

o Highly developed countries rely on Highly developed countries rely on mineral deposits in developing mineral deposits in developing countriescountries• They have exhausted their own suppliesThey have exhausted their own supplies

o Governments in developing countries Governments in developing countries lack financial resources to handle lack financial resources to handle pollutionpollution• Acid mine drainageAcid mine drainage• Air and water pollutionAir and water pollution

North American Consumption of North American Consumption of Selected MetalsSelected Metals

Will We Run Out of Important Will We Run Out of Important Metals?Metals?

o Mineral ReservesMineral Reserves• Mineral deposits that have been identified Mineral deposits that have been identified

and are currently profitable to extractand are currently profitable to extract

Increasing Supply of Minerals –Increasing Supply of Minerals –Locating and Mining New DepositsLocating and Mining New Deposits

o Many known mineral deposits have not Many known mineral deposits have not yet been exploitedyet been exploited• Difficult to accessDifficult to access

• Ex: Malaria ridden forests of IndonesiaEx: Malaria ridden forests of Indonesia• Insufficient technologyInsufficient technology

• Ex: polar regionsEx: polar regions• Located too deepLocated too deep

• Ex: 10km or deeperEx: 10km or deeper

Increasing Supply of Minerals –Increasing Supply of Minerals –Minerals in AntarcticaMinerals in Antarctica

o No substantial mineral deposits No substantial mineral deposits identified to dateidentified to date• Geologists feel they will be discovered in Geologists feel they will be discovered in

near futurenear future• No one owns AntarcticaNo one owns Antarctica

o Antarctica Treaty (1961)Antarctica Treaty (1961)• Limits activity to peaceful uses (i.e. Limits activity to peaceful uses (i.e.

scientific studies)scientific studies)

o Madrid Protocol (1990)Madrid Protocol (1990)• Moratorium on mineral exploration and Moratorium on mineral exploration and

development for minimum of 50 yearsdevelopment for minimum of 50 years

Increasing Supply of Minerals- Increasing Supply of Minerals- Minerals from the OceanMinerals from the Ocean

o May provide us with future suppliesMay provide us with future supplies• Extracting minerals from seawaterExtracting minerals from seawater• Mining seafloor- Manganese nodules Mining seafloor- Manganese nodules

(below)(below)

Advance Mining and Processing Advance Mining and Processing TechnologiesTechnologies

o Special techniques to make use of Special techniques to make use of large, low-grade mineral deposits large, low-grade mineral deposits world-wideworld-wide• Currently requires a lot of energyCurrently requires a lot of energy

o BiominingBiomining• Using microorganisms to extract minerals Using microorganisms to extract minerals

from low-grade oresfrom low-grade ores

Finding Mineral SubstitutesFinding Mineral Substitutes

o Important goal in manufacturingImportant goal in manufacturing• Driven by economics- cut costs!Driven by economics- cut costs!

o Substitute expensive/scarce mineral Substitute expensive/scarce mineral resources for inexpensive/abundant onesresources for inexpensive/abundant ones

o Examples: Examples: • Using plastic, glass or aluminum in place of Using plastic, glass or aluminum in place of

tintin• Using plastic instead of lead and steel in Using plastic instead of lead and steel in

telecommunications cablestelecommunications cables• Using glass fibers instead of copper wiring in Using glass fibers instead of copper wiring in

telephone cablestelephone cables

Mineral ConservationMineral Conservation

o Includes reuse and recycling of existing Includes reuse and recycling of existing mineral suppliesmineral supplies• Reuse- using items over and over againReuse- using items over and over again

• Reduces both mineral consumption and pollutionReduces both mineral consumption and pollution• Benefits greater than recyclingBenefits greater than recycling

• Recycling- converting item into new productRecycling- converting item into new product• Common practice throughout industrialized worldCommon practice throughout industrialized world• Reduces land destruction from miningReduces land destruction from mining• Reduces solid wasteReduces solid waste• Decreases energy consumption and pollutionDecreases energy consumption and pollution

Changing Our Mineral Changing Our Mineral RequirementsRequirements

o Must change out “throw away” Must change out “throw away” mentalitymentality• Damaged or unneeded articles are thrown Damaged or unneeded articles are thrown

awayaway

Mineral Flow in an Industrial SocietyMineral Flow in an Industrial Society