Mining

By 1852, mining operations were well under way on the American River near Sacramento.

Open Pit Mine

Commonly mined materials and end uses Mined material End uses Coal Generating electricity, making iron and steel, manufacturing chemicals and other products. Sand and gravelBuilding roads, homes, schools, offices, and factories. Iron oreSteel products (kitchen utensils, automobiles, ships, buildings). Aluminum ore (bauxite) Military aircraft, naval vessels, pots and pans, beverage cans. Copper oreElectrical motors, generators, communications equipment, wiring. Silver oreElectric and electronics circuitry, coins, jewelry, photographic film. Gold oreJewelry, satellites, sophisticated electronic circuits. Zinc Diecasting, galvanizing brass and bronze, protective coatings on steel, chemical compounds in rubber and paints. LeadBatteries, solder, electronic components. Clay Bricks, paper, paint, glass, pottery, linoleum, concrete, wallboard, spackling, pencils, microwavable containers, vegetable oil. GypsumConcrete, wallboard, spackling, caulking, potting soil. PhosphatePlant fertilizers. SaltCooking, drinking water, plastics, highway de-icing, detergents.

In the solution mining method of extraction, water is forced under pressure into a cavity which forms in the underground salt bed, as the salt dissolves. This turns the water into brine containing about 30% salt. The saturated raw brine is pumped to the purification plant where calcium, magnesium and other impurities are removed, prior to the evaporation process.

The illustration above shows a drift type of underground mine. A mine opening is made at the same elevation as the coals seam and mining is conducted using typically either longwall mining or room and pillar mining with continuous mining equipment. Coal is transported to the surface by conveyor belts. This method of mining is used when the coal seam outcrops at the surface, or when a bench has to be constructed on a mountain side to mine the coal.

The illustration shows a shaft type of underground mine. A mine opening is made by sinking a shaft down to the elevation of the coal seam. Mining is conducted using typically either longwall mining or room and pillar mining with continuous mining equipment. Coal is transported to the surface by a skip hoist. This is the most expensive type of underground mine to build and operate. This method of mining coal is usually utilized when the coal seam is deep below the surface.

The illustration above shows a slope type of underground mine. A mine opening is made by tunneling from the surface down to the elevation of the coal seam. Mining is conducted using typically either longwall mining or room and pillar mining with continuous mining equipment. Coal is transported to the surface by conveyor belts. This method of mining coal is usually utilized when the coal seam is not far from the surface, and the outcrop of the coal seam is not exposed.

Reclamation plans include many of the following concerns: drainage control, preservation of top soil, segregation of waste material, erosion and sediment control, solid waste disposal, control of fugitive dust, regrading, and restoration of waste and mine areas. The plan must also consider the effects of mine subsidence, vibration (induced by mining, processing, transport, or subsidence), and impact on surface water and groundwater. These environmental items often dictate the economics of a planned mining operation and determine its viability.

Pyritic mine tailings leach acid mine drainage originating in a large part to the metabolic activity of Thiobacillus ferrooxidans(5). This bacterial microbe has been implicated as the major culprit in the pollution of streams emanating from active and abandoned mining operations. Abiotic oxidation of pyrite is slow. T. ferrooxidans catalyzes the oxidation of FeS 2, producing ferric ions and hydrogen ions. mine tailingspyrite Acid Mine Drainage s_home/jhoran/ch126/ microbia.htm

ch126/amd.htm AMD (Acid Mine Drainage)

_Destruction/Mining / Mining, particularly gold mining, is an increasing threat to the world's rainforests and to forest communities.

 1,600 kg (3,600 lb) of aluminum  360 kg (800 lb) of zinc  11,300 kg (25,000 lb) of clay  25,400 kg (56,000 lb) of steel  360 kg (800 lb) of lead  680 kg (1,500 lb) of copper  12,200 kg (27,000 lb) of salt  More than 226,000 kg (500,000 lb) of coal  More than 453,000 kg (1 million lb) of stone, sand, gravel, and cement. During the lifetime of the average American, he or she will use:

Possible Science Fair Experiment 26/amd.htmhttp:// 26/amd.htm