The Mining industry of Ghana accounts for 5% of the country's GDP and minerals make up 37% of total exports, of which gold contributes over 90% of the total mineral exports. . Thus, the main focus of Ghana's mining and minerals development industry remains focused on go
Mining was Zimbabwe's leading industry in 2002, contributing 27% of export trade. The chief minerals were coal, gold, copper, nickel, tin, and clay, and Zimbabwe was a world leader in the production of lithium minerals, chrysotile asbestos, and ferrochromium, with more than half of the world's known chromium reserves.
A. Abutment - In coal mining, (1) the weight of the rocks above a narrow roadway is transferred to the solid coal along the sides, which act as abutments of the arch of strata spanning the roadway; and (2) the weight of the rocks over a longwall face is transferred to the front abutment, that is, the solid coal ahead of the face and the back abutment, that is, the settled packs behind the face.
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Back — The roof or upper part in any underground mining cavity. Backfill — Mine waste or rock used to support the roof after coal removal. Barren — Said of rock or vein material containing no minerals of value, and of strata without coal, or containing coal in seams too thin to be workable.