WorldWide Drilling Resource

34 JUNE 2018 WorldWide Drilling Resource ® Dolomite is both a mineral and a rock. The mineral is the pure form with a defined crystal struc- ture and chemical formula. Dolomite rock is com- posed mainly of the mineral dolomite, but contains impurities. It is one of the three most abundant carbonate minerals, and is usually found with a white to gray color. In sedimentary basins around the world, magnesium-rich groundwater is thought to alter lime mud and limestone to form dolomite. A French geologist named Deodat de Dolomieu (1750-1801) was the first to identify the mineral’s chemical composition. Dolomieu first chose a military career, but those pursuits came to an abrupt end after he was condemned to death at the age of 18 for killing a fellow soldier in a duel. After being pardoned, he decided to spend the remainder of his life pursuing rocks and minerals. In addition to having the mineral named after him, a mountain range in northeastern Italy, where he worked was later given the name “Dolomites” in his honor. Dolomite is mostly mined from open quarries, although in many areas economic and environmental factors favor large- scale production by underground mining. The basic elements of surface mining are overburden removal, drilling, blasting, and hauling ore to the crushing and processing plant. Mining equipment varies with the particular requirements at each operation. The basic operations in underground mining are drilling, blasting, loading, hauling, scaling, and roof bolting. Smaller blast- holes and a lower volume of rock is usually produced with each blast in an under- ground mine. Drilling equipment includes horizontal drills and downhole track drills. Most underground mines are room-and-pillar-type operations, and many re- cover rock from both headings and benches. A V-type drill pattern is usually used to maximize the amount of rock produced with each shot, reducing the amount of unbroken rock in the shot face. Other equipment required includes powder loaders, which are used to blow ammonium nitrate-fuel oil mixtures into the blastholes. Scal- ing 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. Dolomite is a major source for concrete used to build roads and infrastructure. It is also used as dolostone and dolomitic marble building stones, as well as in the manufacture of glass and ceramic glazes. Powdered dolomite is a component of many fertilizers and animal feeds. Smaller amounts of dolomite are also used for human consumption as a mineral supplement and antacid, as well as in facial creams and toothpaste. It is also an important source for magnesium and calcium metals. Blast furnaces often use it as a flux, which is a material capable of easily melting, with an ability to remove impurities from metal ores or make the slag produced by metal ore smelting more fluid so it can be disposed of more easily. The World of Minerals EXB