The process of mining from discovery of an ore body through extraction of minerals and finally to returning the land to its natural state consists of several distinct steps. The first is discovery of the ore body, which is carried out through prospecting or exploration to find and then define the extent, location and value of the ore body. This leads to a mathematical resource estimation to estimate the size and grade of the deposit. A quarry is a type of open-pit mine from which rock or minerals are extracted. Quarries are generally used for extracting building materials, such as dimension stone, construction aggregate, riprap, sand, and gravel. They are often colocated with concrete and asphalt plants due to the requirement for large amounts of aggregate in those materials. The word quarry can include underground quarrying for stone, such as Bath stone Gold mining consists of the processes and techniques employed in the removal of gold from the ground. There are several techniques by which gold may be extracted from the earth
Hard rock gold mining is done when the gold is encased in rock, rather than found as particles in loose sediment. Hard rock mining produces most of the worlds gold. Sometimes open-pit mining is used, such as at the Ft. Knox Mine in central Alaska. Barrick Gold Corporation has one of the largest open-pit gold mines in North America, located on its Goldstrike mine property in northeastern Nevada. Other gold mines use underground mining, where the ore is extracted through tunnels or shafts. South Africa has the worlds deepest hard-rock mine, which mines gold from as deep as 3900 meters under the ground.
From Wikipedia, the free encyclopedia : Mining and quarrying Other |