tac dong moi truong 3
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Potential Environmental Potential Environmental ProblemsProblems
A. Mining operation itselfA. Mining operation itself– Disposal of a large amount of rock and Disposal of a large amount of rock and
wastewaste– NoiseNoise– DustDust
BeneficiationBeneficiation Smelting and refiningSmelting and refining
From Underground MiningFrom Underground Mining
SubsidenceSubsidence– Block/cavingBlock/caving– Room and pillarRoom and pillar– Salt miningSalt mining
Subsidence in rancher’s Subsidence in rancher’s fieldfield
Subsidence from Pb-Zn Subsidence from Pb-Zn miningmining
From UndergroundFrom Underground
Acid Mine DrainageAcid Mine Drainage– FeS minerals in coalFeS minerals in coal– Sulphide depositsSulphide deposits– Acidic streams can pick up heavy Acidic streams can pick up heavy
elements and transport themelements and transport them
Rock that has acid forming Rock that has acid forming materialmaterial
DrainageDrainage
Acid and open pitsAcid and open pits
Berkley Pit
Other problems with open Other problems with open pitspits
Very large holesVery large holes Pit slopes steep and not stable. Pit slopes steep and not stable.
Cannot be maintainedCannot be maintained May fill with water May fill with water Strip coal mines –loss of top soil in Strip coal mines –loss of top soil in
pastpast– Now smoothed out and top soil addedNow smoothed out and top soil added
Disposal of Waste RockDisposal of Waste Rock
More problematic for open pit than More problematic for open pit than undergroundunderground
Waste rock piles have steep angle of Waste rock piles have steep angle of repose and thus may not be stablerepose and thus may not be stable
Bingham in its hay day produced Bingham in its hay day produced 400,000 tons of waste rock per DAY!400,000 tons of waste rock per DAY!
Tailings pondsTailings ponds
From concentrating usually have From concentrating usually have high pHhigh pH– At Bingham acid waters mixed with At Bingham acid waters mixed with
tailings water to neutralizetailings water to neutralize Different metals have different Different metals have different
problemsproblems
Problems with Problems with Smelting/RoastingSmelting/Roasting
Air: SOAir: SO22 and CO and CO22 and particulate and particulate mattermatter
Noranda Quebec used to have the Noranda Quebec used to have the highest single point source of SOhighest single point source of SO22 in in the world. It may have been the world. It may have been surpassed.surpassed.
CN (Au); NaOH and F (Al); solvents CN (Au); NaOH and F (Al); solvents (electrotwinning); heavy metals; oil (electrotwinning); heavy metals; oil and greaseand grease
Environmental ImpactEnvironmental Impact
Environmental impactEnvironmental impact– From mineral exploration and testingFrom mineral exploration and testing– From mineral miningFrom mineral mining– From mineral resources refiningFrom mineral resources refining– From mining waste disposalFrom mining waste disposal
Environment Impact of Mineral Environment Impact of Mineral DevelopmentDevelopment
The impact depends upon many factors:The impact depends upon many factors:– Mining proceduresMining procedures– Hydrologic conditionsHydrologic conditions– Climate factorsClimate factors– Types of rocks and soilsTypes of rocks and soils– TopographyTopography
Also population: NIMBYAlso population: NIMBY
Impact of Mineral Exploration and Impact of Mineral Exploration and TestingTesting
Mineral exploration and testingMineral exploration and testing– Surface mapping, geochemical, Surface mapping, geochemical,
geophysical, and remote-sensing data geophysical, and remote-sensing data collectioncollection
– Test drillingTest drilling ImpactImpact
– Generally minimal impactGenerally minimal impact– More planning and care needed for More planning and care needed for
sensitive areas (arid, wetlands, and sensitive areas (arid, wetlands, and permafrost areas)permafrost areas)
General impactGeneral impactDirect impact on land, water, air, and Direct impact on land, water, air, and
biological environmentbiological environment Indirect impact on the environment: Indirect impact on the environment:
Topographic effect, transportation of Topographic effect, transportation of materials, etc.materials, etc.
Impact on social environment: Impact on social environment: Increased demands for housing and Increased demands for housing and servicesservices
Impact of Mineral Impact of Mineral ExtractionExtraction
and Processing (1)and Processing (1)
Impact of Mineral ExtractionImpact of Mineral Extractionand Processing (2)and Processing (2)
Impact from mining operationsImpact from mining operations– Land disturbances; e.g., Land disturbances; e.g., – Waste from mines: 40% of the mining area for waste Waste from mines: 40% of the mining area for waste
disposal, mining waste 40% of all solid wastes; e.g., disposal, mining waste 40% of all solid wastes; e.g., , ,
– Special mining, e.g., chemical leaching from gold Special mining, e.g., chemical leaching from gold mining; e.g., mining; e.g.,
– Mining acid drainage, during mining and post-mining; Mining acid drainage, during mining and post-mining; e.g., New World districte.g., New World district
Berkeley Pit.kmz
ASARCO tailings.kmzChico placer.kmz
Golden Sunlight.kmz
Mclaren tailings.kmz
Impact of Mineral ExtractionImpact of Mineral Extractionand Processing (4) and Processing (4)
Water pollutionWater pollution– Trace elements leaching out into water, Trace elements leaching out into water,
such as Cd, Co, Cu, Pb, Mo, Znsuch as Cd, Co, Cu, Pb, Mo, Zn– Flooding of abandoned mines, oxidation Flooding of abandoned mines, oxidation
of sulfide ores = sulfuric acidof sulfide ores = sulfuric acid– Acid mine drainage from tailingsAcid mine drainage from tailings
Pollution of water from Pollution of water from miningmining
Minimizing the Impact of Minimizing the Impact of Mining (1)Mining (1)
Knowledge and technology transfer: developed Knowledge and technology transfer: developed countries to developing countriescountries to developing countries
Environmental Regulations: Environmental Regulations: Forbid bad Forbid bad mining practices, Clean Air Act, and on- and mining practices, Clean Air Act, and on- and offsite treatment of wastesoffsite treatment of wastes
Land reclamation: Land reclamation: AAbout 50% of land used in bout 50% of land used in mining industry reclaimedmining industry reclaimed
Use of new biotechnology in mining: Use of new biotechnology in mining: Bio-Bio-oxidation, bioleaching, biosorption, genetic oxidation, bioleaching, biosorption, genetic engineeringengineering
Figure 14.14Figure 14.14
Minimizing the Impact of Minimizing the Impact of Mining (2)Mining (2)
Recycling Mineral Resources Recycling Mineral Resources (1)(1)
Why recycle? Consider the impact of the Why recycle? Consider the impact of the wasteswastes– Toxic to humansToxic to humans– Dangerous to natural ecosystemsDangerous to natural ecosystems– Degradation of air, water, and soilDegradation of air, water, and soil– Use of land for disposalUse of land for disposal– Aesthetically undesirableAesthetically undesirable
Waste contains recyclable materials Waste contains recyclable materials Saves energy, money, land, raw mineral Saves energy, money, land, raw mineral
resources from more miningresources from more miningSaves energy and money when Saves energy and money when
recycling instead of refining raw ore recycling instead of refining raw ore materialsmaterials
Recycling has been proven to be Recycling has been proven to be profitable and workableprofitable and workable
Recycling Mineral Recycling Mineral Resources (2)Resources (2)
Most-recycled metals: Iron and steel, Most-recycled metals: Iron and steel, 90% by weight90% by weight
One-third as much energy needed to One-third as much energy needed to produce steel from recycled scrap as produce steel from recycled scrap as from original orefrom original ore
More than $40 billion produced from More than $40 billion produced from recycled metals in 1998recycled metals in 1998
Other recycled metals: Lead (63%), Other recycled metals: Lead (63%), aluminum (38%), and copper (36%)aluminum (38%), and copper (36%)
Recycling Mineral Resources Recycling Mineral Resources (3)(3)
Life cycle of a metal Life cycle of a metal resourceresource
Sustainability: long-term strategy for Sustainability: long-term strategy for consuming the resourcesconsuming the resources
Find an alternative material for the Find an alternative material for the metal, e.g., glass fiber cable for copper metal, e.g., glass fiber cable for copper wireswires
Use raw materials more efficientlyUse raw materials more efficientlyMore R&D on innovative substitutes or More R&D on innovative substitutes or
ways to keep the R/C ratio, a solution to ways to keep the R/C ratio, a solution to the depletion of nonrenewable the depletion of nonrenewable resourcesresources
Minerals and SustainabilityMinerals and Sustainability
Considering the fact that mineral resources are Considering the fact that mineral resources are nonrenewable, do you believe that technology nonrenewable, do you believe that technology will eventually help to meet the growing demand will eventually help to meet the growing demand for mineral resources? If yes, explain.for mineral resources? If yes, explain.
Biotechnology shows the potential for cleaner Biotechnology shows the potential for cleaner minerals extraction and waste disposal. Will minerals extraction and waste disposal. Will biotechnology bring about any environmental biotechnology bring about any environmental problems?problems?
What types of environmental impact would occur What types of environmental impact would occur ififwe increasingly extract more mineral resources we increasingly extract more mineral resources from the seafloor?from the seafloor?
Applied and Critical Thinking Applied and Critical Thinking TopicsTopics
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