Is used to extract valuable minerals from the earth - PowerPoint Presentation

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Is used to extract valuable minerals from the earthIs dependent on crustal abundanceElements and minerals are not equally represented or distributed in the earth’s crustCountries and companies have mineral reservesKnown quantity that can be realistically recovered by mining

Mining

Relative crustal abundance

of most common mineralsSlide2
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Sand and gravelMetalsPhosphatesSaltsSodiumSulfurGemstonesFuel sourcesCoal

Uranium

Mined MaterialsSlide4

Concentrated accumulations of minerals formed from geologic processesCan also contain waste materialMust usually be processed to produce a pure form of the mineralCan occur in veinsLocalized high concentrations of a mineralCan occur in disseminated depositsLarge, widely spread lower concentrations of a mineral

OreSlide5

Surface MiningPlacerStripMountaintop RemovalOpen PitSubsurface MiningShaftSolution*Ocean Mining*

Types of MiningSlide6
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Used when a resource accumulates in riverbed depositsRunning water is used to sift lighter materials from the heavier resource materialsAlso called panningDisturbs large amounts of sediment

Placer MiningSlide8

Used when a resource exists in layers near the Earth’s surfaceRock and soil above the resource (overburden) is removed from a strip of landMined material is removed and overburden is replaced

Strip MiningSlide9

Used when a resource occurs in seams near mountain ridgesEntire mountaintops are bulldozed and blasted away to reveal the seamOverburden is replaced on the remaining mountain, and may fall or be dumped into adjacent valleys

Mountaintop MiningSlide10

Used when a resource is in an area unsuitable for tunneling, or when it is spread evenly and close to the surface Called a quarry

Open Pit MiningSlide11

Used when a resource occurs deep undergroundVertical shafts are dug into the groundHorizontal tunnels are dug to follow the seam or deposit being minedMaterial is removed and sent to the surface for processing

Subsurface MiningSlide12

Also called in-situ recoveryUsed when a resource is buried deep, and can be dissolved in liquidA hole is drilled to the resource, and water or acid is poured into the holeThe resource is sucked out and processed to remove it from the fluid

Solution Mining*Slide13
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Used when resource deposits exist on or under the sea floor, or in seawaterResources are “vacuumed” off the sea floorResearch is underway to extract or evaporate resources from seawater

Ocean Mining*Slide17
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All mining uses machinery and transportation that produces pollutionAll mining produces tailings, or mineral waste that can damage ecosystemsThe processing of ore can produce toxic byproductsMiners are exposed to some of the most hazardous working conditions on the planet

Problems with MiningSlide19

Most harmful form of environmental damage from miningOccurs when newly exposed rock that contain sulfur reacts with water and oxygen to form sulfuric acid

Acid Drainage*Slide20

Sulfuric acid leaches metals from nearby rock and soilForms toxic acidic liquid called leachateCleanup involves neutralizing the acid and removing the metals

Acid Drainage*Slide21

Brownfields* Abandoned sites polluted with hazardous wasteIncludes abandoned minesDangerous and difficult to clean up for reuseFall under EPA Superfund sitesSlide22

Goal is to restore a mined site to as close to its original condition as possibleInvolves:Filling in shafts and holesRemoving mining structures and equipmentReplacing overburdenReplantingEcosystems never fully recover from mining disruption

Mine Restoration or ReclamationSlide23
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Any individual or company can stake an exclusive claim on federal land open for miningLand can be patented, or bought outright, for about $5/acreNo payments are made to the government, even if profits are realizedIncludes gemstones, metals, uranium and minerals

General Mining Act of 1872Slide26

Public lands must be leased for mining, and royalties on profits are to be paidAmounts depend on the resource being minedCovers fossil fuels, sodium, sulfur, and phosphates

Mineral Leasing Act of 1920*Slide27

Regulates the surface effects of coal miningMandates reclamation of mined areas

Surface Mining Control and Reclamation Act of 1977Slide28

Minerals regenerate slowlyMany mineral deposits are being mined very quicklyAs they become scarce, they will become more expensiveEnvironmentally friendly alternatives are being sought, including recycling

Minerals are Nonrenewable*Slide29

Recycling is the best way to sustainably use many mineralsUses less energy in production of goodsReduces the amount of miningRecycling e-waste is especially importantReducing the use of products that contain minerals also helps

Sustainable Mineral Use*Slide30
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