Abandoned uranium mine

Mining Minerals and fossil fuels are mined from the earth’s crust. Method of removal depends on: Depth at which the resources is located Amount and stability of the material that must be removed to reach the mineral (overburden) Topography of the area Safety concerns Economics

Mining Techniques Surface (strip) mining- deposits lie horizontally to earth’s surface Mountaintop removal- coal seams are exposed by removing the top of a mountain using explosives and/or heavy equipment Open-pit mining- using explosives and heavy equipment Subsurface mining- deep vertical mine shafts with horizontal tunnels branching off Acid mine drainage Drilling- to remove liquids and gases (oil, natural gas and steam)

Figure 14-10: Natural capital degradation: This spoils pile in Zielitz, Germany, is made up of waste material from the mining of potassium salts used to make fertilizers. Fig. 14-10, p. 358

Figure 14-11: Natural capital degradation: Kennecott’s Bingham Canyon Mine in the U.S. state of Utah has produced more copper than any mine in history. This gigantic open-pit mine is almost 5 kilometers (3 miles) wide and 1,200 meters (4,000 feet) deep, and it is getting deeper. Fig. 14-11, p. 358

Strip Mining Undisturbed land Overburden Highwall Coal seam Overburden Pit Bench Coal seam Figure 14-13: Natural capital degradation: Contour strip mining is used in hilly or mountainous terrain. Strip Mining Spoil banks Fig. 14-13, p. 359

Environmental Costs of Mining Extracting minerals from the earth’s crust and converting them into useful products can: Disturb the land- habitat above the deposit must be destroyed by clear-cutting forests and removing vegetation = overburden Erode soils Produce large amounts of solid waste *** 75% of all US solid waste comes from mining *** Pollute the air, water, and soil Streams and rivers clouded by sediment Wastewater with hazardous chemicals leached from mine waste

Acid Mine Drainage Occurs when sulfur compounds in mine waste are exposed to air, oxidize and dissolve in rainwater to form a sulfuric acid solution. Acidic runoff enters waterways causing significant ecological damage similar to acid rain. Figure 14-15: Acid mine drainage from an abandoned open-pit coal mine in Portugal. Fig. 14-15, p. 360

Mineral Use Creates Environmental Impacts Metal product life cycle Mining, processing, manufacture, and disposal Environmental impacts Determined by an ore’s grade Percentage of metal content Mining Metal ore Separation of ore from waste material Smelting Melting metal Conversion to product Discarding of product Recycling

Case Study: The Real Cost of Gold At about 90% of the world’s gold mines Mineral extracted with cyanide salts Cyanide is extremely toxic Mining companies declare bankruptcy Allows them to avoid environmental remediation The town of Kalgoorlie, next to Australia's Fimiston Open Pit mine 

Removing Metals from Ores Has Harmful Environmental Effects Ore extracted by mining Ore mineral Tailings – waste material Smelting using heat or chemicals causes: Air pollution Water pollution

Metallic mineral resources Aluminum (bauxite) Iron Lead Chromium Manganese Nickel Silver Gold How is aluminum made?

Nonmetal mineral resources Sand Gravel Limestone Clay Asbestos Talc Salt

Mineral Processes In some cases removal of metals from ores can cause more damage to the environment than the mining of the ore and a much greater hazard to human health  Smelting- heating of ores to remove metals produces air pollution that includes heavy metals, particulate matter, and sulfur dioxide (acid rain) ASARCO- think of the workers and community near the smelter. What happened to Smelter Town?

Mineral Processes Cyanide Solution Mining or Heap- Leach Extraction- practice of spraying cyanide solution on piles of crushed ore to dissolve and extract gold creates holding ponds of cyanide- laced water that may seep into groundwater and run off to local waterways

Recycling and Mineral Reserves *** Recycling aluminum cans consumes about 5% of the energy and eliminates most of the environmental costs associated with mining and smelting the aluminum ore (bauxite) *** Reserve is a location from which a mineral can be extracted in an economically viable manner.