Limestone is a sedimentary rock composed mostly of the mineral calcite and comprising about 15% of the Earth’s sedimentary crust. It is a basic building block of the construction industry (dimension stone) and a chief material from which aggregate, cement, lime and building stone are made. 71% of all crushed stone produced in the India is either limestone or dolomite. As a source for lime, it is used to make paper, plastics, glass, paint, steel, cement, carpets, used in water treatment and purification plants and in the processing of various foods and household items (including medicines).
Type
- Rock
Description
Limestone is a sedimentary rock composed mostly of the mineral calcite and comprising about 15% of the Earth’s sedimentary crust. It is a basic building block of the construction industry (dimension stone) and a chief material from which aggregate, cement, lime and building stone are made. 71% of all crushed stone produced in the India is either limestone or dolomite. As a source for lime, it is used to make paper, plastics, glass, paint, steel, cement, carpets, used in water treatment and purification plants and in the processing of various foods and household items (including medicines).
Uses
The largest use of lime is in steel manufacturing where lime is used as a flux to remove impurities such as phosphorus and sulfur. Lime is used in power plant smokestacks to remove sulfur from the emissions. Lime is also used in mining, paper and paper pulp production, water treatment and purification, and in wastewater treatment. It is used in road construction and traditional building construction.
Relation to Mining
Most limestone and dolomite are mined from open quarries, although in many areas economic and environmental considerations favor large-scale production by underground mining. The only carbonate materials not consistently recovered by surface or underground mining are shell products that are dredged from parts of India.
Surface Limestone Mining:
The basic elements of surface mining are overburden removal, drilling, blasting and hauling ore to the crushing and processing plant. The selection of surface mining equipment varies with the particular requirements at each operation, including production capacity required, size and shape of the deposit, haul distances, estimated life of the operation, location relative to urban centers, and other social and economic factors. Other factors that must be considered in surface mining are the value of the products produced, location of competitive operations, and environmental and safety requirements associated with a particular deposit.
Underground Limestone Mining:
The basic operations in underground mining are drilling, blasting, loading and hauling, scaling and roof bolting. Drilling equipment includes horizontal drills and down hole track drills. This equipment is generally quite different from that used for surface mining and results in much smaller blast holes and a lower volume of rock produced with each blast. Other equipment required in the underground mine includes powder loaders, which are used to blow ammonium nitrate–fuel oil mixtures into the blast holes. Scaling rigs, which are used to remove loose rocks from the ribs and roof of the mine, and roof-bolting equipment may also be required in an underground mine.
