potential environmental problems

Environment Impact of Mineral... Impact of Mineral Exploration and Testing Mineral exploration and testing remote-sensing data collection  Impact areas arid, wetlands, and permafrost a

Potential Environmental Problems

 A Mining operation itself

From Underground Mining

 Subsidence

Subsidence in rancher’s field

Subsidence from Pb-Zn mining

From Underground

 Acid Mine Drainage

and transport them

Rock that has acid forming material

Drainage

Acid and open pits

Berkley Pit

Other problems with open pits

 Very large holes

 Pit slopes steep and not stable Cannot be maintained

 May fill with water

 Strip coal mines –loss of top soil in past

Disposal of Waste Rock

 More problematic for open pit than

underground

 Waste rock piles have steep angle of

repose and thus may not be stable

 Bingham in its hay day produced 400,000 tons of waste rock per DAY!

Tailings ponds

 From concentrating usually have high pH

water to neutralize

 Different metals have different problems

Problems with Smelting/Roasting

 Air: SO2 and CO2 and particulate matter

 Noranda Quebec used to have the highest single point source of SO2 in the world It may have been surpassed

 CN (Au); NaOH and F (Al); solvents

(electrotwinning); heavy metals; oil and grease

Environmental Impact

 Environmental impact

Environment Impact of Mineral

Impact of Mineral Exploration and Testing

 Mineral exploration and testing

remote-sensing data collection

 Impact

areas (arid, wetlands, and permafrost areas)

General impact

 Direct impact on land, water, air, and

biological environment

 Indirect impact on the environment:

Topographic effect, transportation of

Impact of Mineral Extraction

and Processing (2)

 Impact from mining operations

– Land disturbances; e.g.,

– Waste from mines: 40% of the mining area for waste

disposal, mining waste 40% of all solid wastes; e.g., ,

– Special mining, e.g., chemical leaching from gold mining;

e.g.,

– Mining acid drainage, during mining and post-mining; e.g.,

New World district

Berkeley Pit.kmz

ASARCO tailings.kmz Chico placer.kmz

Golden Sunlight.kmz

Mclaren tailings.kmz

Impact of Mineral Extraction

and Processing (4)

 Water pollution

as Cd, Co, Cu, Pb, Mo, Zn

sulfide ores = sulfuric acid

Pollution of water from mining

Minimizing the Impact of

Mining (1)

countries to developing countries

practices, Clean Air Act, and on- and offsite

treatment of wastes

industry reclaimed

bioleaching, biosorption, genetic engineering

Figure 14.14

Minimizing the Impact of

Mining (2)

Recycling Mineral Resources (1)

 Why recycle? Consider the impact of the

wastes

 Waste contains recyclable materials

 Saves energy, money, land, raw mineral

resources from more mining

 Saves energy and money when recycling instead of refining raw ore materials

 Recycling has been proven to be profitable and workable

Recycling Mineral Resources

(2)

 Most-recycled metals: Iron and steel, 90% by weight

 One-third as much energy needed to produce steel from recycled scrap as from original ore

 More than $40 billion produced from recycled metals in 1998

 Other recycled metals: Lead (63%),

aluminum (38%), and copper (36%)

Recycling Mineral Resources (3)

Life cycle of a metal resource

 Sustainability: long-term strategy for

consuming the resources

 Find an alternative material for the metal,

e.g., glass fiber cable for copper wires

 Use raw materials more efficiently

 More R&D on innovative substitutes or ways

to keep the R/C ratio, a solution to the

depletion of nonrenewable resources

Minerals and Sustainability

 Considering the fact that mineral resources are

nonrenewable, do you believe that technology will

eventually help to meet the growing demand for mineral resources? If yes, explain.

extraction and waste disposal Will biotechnology bring about any environmental problems?

we increasingly extract more mineral resources from the seafloor?

Applied and Critical Thinking

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