SOME MINING TERMINOLOGY Back to top
acid mine drainage: Water mixed with sulfuric acid and having a pH of less than 6.0 discharging from an active or abandoned mine and/or the surrounding affected area. When exposed to air, water or weather processes, acid forming earthen materials containing sulfide minerals (principally iron pyrites) oxidate and form the sulfuric acid. The sulfuric acid mixes with the water and flows out of the mine into surrounding waters as acid mine drainage.
adit: A horizontal or nearly horizontal passage driven from the surface of the earth for the working of a mine. If driven through a hill or mountain to the surface on the opposite side, it would be a tunnel.
AML: The Abandoned Mine Land Program
approximate original contour: The surface configuration achieved by backfilling and grading of previously mined areas so that the reclaimed area closely resembles the general surface configuration of the land and surrounding area prior to mining.
back: The roof or upper part in any underground mining cavity. Back to top
coal gob waste : Earthen materials that are separated from the coal product during processing.
coal seam: A bed or layer of coal in the earth.
collar: Timbering or concrete around the mouth or top of a shaft; the junction of a mine shaft and the surface.
concentration/concentrate: A process for reducing the values in an ore to a smaller bulk in order to diminish the expense of shipping and treatment. Concentrate is the reduced ore material which contains the valuable metal from which most of the waste material has been eliminated. Concentrate is then sent to smelters for further treatment.
cribbing: The close setting of timber supports when shaft sinking through loose ground.
cyanide/cyanidation: A salt or ester of hydrocyanic acid which produces a chemical reaction in leaching operations in metal mine processing operations in order to dissolve metal values from gangue materials for later recovery. The practice consists of fine grinding the entire tonnage on a roller, tube, rod, or ball mill. The crushed ore then passes to leaching tanks where a solution of sodium or potassium cyanide is placed in the tank with the ore. The ore then gives up the silver or gold mineral into the solution so that gold can be retrieved in zinc boxes or other methods. The precipitate is then smelted and refined into gold and silver bullion.
disturbed area: An area of land or surface water that has been disturbed by mining activities. The term includes the area from which the overburden, vegetation, topsoil, tailings, waste materials, minerals or coal have been removed; and areas where topsoil, spoil, or mine processing waste were placed by surface mining operations. It also includes tailings ponds, waste dumps, roads, conveyor systems, leach dumps and all similar excavations or coverings that result from mining operations and have not been previously reclaimed.
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drift: A horizontal passage underground.
dump: A pile or heap of waste rock material or other non-ore refuse near a mine.
entry: A haulage road, gangway, or airway to the surface.
gob: Rock or other coarse materials sorted out of coal either during mining or processing. Gob has the consistency of pea-gravel or driveway stone.
groundwater: Subsurface water that fills available openings in rock or soil materials to the extent that they are considered water saturated.
highwall: The vertical wall consisting of the material being mined and the overlying rock and soil strata (overburden) of the mining site.
impoundment: A closed basin, naturally formed or artificially built, which is dammed or excavated for the retention of water, sediment, or waste.
incline: A shaft not vertical; usually on the dip of a vein. Back to top
lagging: Planks, slabs, or small timbers placed over the caps or behind the posts of the timbering, not to carry the main weight, but to form a ceiling or a wall, preventing fragments or rock from falling through.
leaching: The removal in solution of the more soluble minerals by percolating water or extracting a soluble metallic compound from an ore by selectively dissolving it in a suitable solvent, such as water, sulfuric acid, hydrochloric acid, cyanide, etc. A leach pad is a specially prepared area covered by an impervious liner on which ore is placed for leaching. A leach tank is a specially constructed wooden tank in which ore is placed for leaching. Back to top
lining: The brick, concrete, cast iron, or steel casing placed around a tunnel or shaft as a support.
loading chute: A three sided tray for loading or for transfer of material from one transport unit to another.
lode: A mineral deposit in solid rock. Back to top
mill: A mineral processing facility which is a building with machines for grinding and pulverizing ores and extracting metals or producing a product. A mill might have rock crushers and grinders for ore, vats for mixing chemicals with the crushed ore, and machinery for capturing the desired product.
mining: The process of obtaining useful minerals from the earth's crust including both underground and surface workings.
mulch: Vegetation residues or other suitable materials that aid in soil stabilization and soil moisture conservation, thus providing conditions suitable for seed germination and growth.
ore: A mineral or mineral aggregate containing precious or useful metals and which occurs in such quantity, grade and chemical combination as to make extraction commercially profitable. An ore body is a solid and fairly continuous mass of ore which may include low grade ore and waste as well as high grade materials. An ore deposit is a general term applied to rocks containing minerals of economic value in such amount that they can be profitably exploited. The term is also applied to deposits which, though they may not be immediately capable of profitable exploitation, may yet become so by change in the economic circumstances that control their value. Back to top
ore processing: Milling, heap leaching, flotation, vat leaching, or other standard hard-rock mineral concentration processes; and, in the opencut mining context, crushing, screening, and asphalt or concrete plants.
OSM: The United States Department of Interior's Office of Surface Mining Reclamation and Enforcement. This is the federal agency that oversees the work of state agencies enforcing the federal coal mining and reclamation law.
overburden: All of the earth and other materials that lie above a natural mineral deposit and the earth and other material after removal from their natural state in the process of mining.
panning: The hand placer process utilizing a circular steel dish from 10-16 inches in diameter at the top and from 2 to 2.5 inches deep with sloping sides at 35-40 degrees. With a gyratory motion, a miner sorts gravel in the pan, pouring off the larger particles, and leaving the finer heavier materials. Back to top
pH: A symbol for the degree of acidity or alkalinity of a solution. pH values from 0 to 6 indicate acidity and from 8 to 14 indicate alkalinity. A solution with a pH of 7 is considered neutral.
placer mining: The extraction of naturally occurring, scattered or unconsolidated valuable minerals from gravel or alluvium lying above bedrock. Placer mining is also called "dredge mining." Miners remove unwanted sedimentary material with running water which traps the metal ore in sluice boxes.
portal: Any entrance to a mine.
pyrite: A lustrous yellow mineral which is a common iron sulphide occurring abundantly as native ore and serving principally as a source of sulfur in the formation of sulfuric acid in acid mine drainage.
red dog: Material of a reddish color resulting from the combustion of shale and other mine waste dumps on the surface.
revegetate: The act of planting reclaimed land with grasses, flowers, shrubs and trees.
sediment: Matter that settles to the bottom of a liquid; matter deposited by water or wind (i.e. sand, silt, dirt, etc.) Back to top
shaft: A vertical or steeply inclined excavation that is connected to a mine.
SMCRA: The federal law called the Surface Mining Control and Reclamation Act of 1977, passed by Congress to establish minimum national standards for mining and reclamation, and to provide a funding source for the reclamation of abandoned mines.
smelting: The chemical reduction of a metal from its ore and certain fluxes by melting at high temperatures. The non-metallic material floats on top of the heavier metallic constituents in the molten state and remains in that position when it cools and hardens.
soil amendments: Additives to the soil to enhance its productivity, such as fertilizer or agricultural lime.
spoil: Overburden material disturbed or removed from its natural state, or non-ore material removed in gaining access to ore or mineral material in the process of mining. Spoil and mining waste materials are disposed of or piled in waste dumps and spoil piles.
stope: An excavation in which ore has been excavated in a series of steps.
subsidence: The collapsing of overburden materials resulting from underground mining or associated underground excavations that cause depressions or holes on the surface and damage to structures.
subsoil: The layer of soil beneath the topsoil. Back to top
tailings: The refuse material resulting from washing, concentrating or treating ground ore that is discharged from a mill. A tailings pond is a pond of water with a constraining wall or dam into which mill effluents are deposited.
talus: A heap of coarse rock waste at the foot of a cliff.
tipple: Originally the place where the mine cars were tipped and emptied of their coal, and still used in that sense, although now more generally applied to the surface structures of a mine, including the preparation plant and loading tracks.
topsoil: The upper surface layer of soil, usually darker and richer than the subsoil, that is naturally present and necessary for the growth and regeneration of vegetation on the surface of the earth. vegetation: In the context of reclamation activities, vegetative cover is the type of vegetation, grass, shrubs, trees, or any other form of natural cover considered suitable at the time of reclamation. Usually, plants used to revegetate a reclamation site are those that are native to the surrounding area.
waste rock dump: Waste rock that was mined and disposed in the vicinity of a mining operation, often at or near the entrance of an adit.
winze: Interior mine shaft. |