Barite ores

BARITE ORES (EN: barite ores; DE: Baryterze; FR: minerais barytiques; ES: minerales de baritina; RU: баритовые руды) are the natural mineral formations, which are containing barite in such concentrations, for which its extraction and utilization are technically possible and economically feasible. The deposits of the barite ores are sub-divided into the barite proper and complex ones, prevalently the sulphide-barite ones. There belong to the first ones those, within which barite is the single or main useful component.

The barite ores proper are sub-divided according to their mineral composition into the substantially barite ones, quartz-barite ones, calcite-barite ones, and others. There exist within them as impurities oxides of iron, sulphides of lead, zinc, copper, and also gold; the concentrations of the latter ones may reach the values, which are of interest during the comprehensive processing of the ores. There may belong to the composition of the barite ores the witherite, the content of which reaches several tens of %. The established global reserves of the barite ores proper, which are containing more than 50% of barite, amount to approximately 300 million tonnes (1980). The complex barite ores are sub-divided into the barite-fluorite ones, barite-pyrite ones, barite-polymetallic ones, barite-celestine ones, and others; barite is extracted from them as the by-product component (see the "Pyrites", "Polymetallic ores", "Copper ores" articles).

According to the conditions for the forming of the barite ores, there are distinguished the following genetic types of deposits:

1) the hydrothermal ones, medium-temperature and low-temperature ones, among which they distinguish the veinous (the most common) ones, which are having the shape of the tabular and lenticular veins with the length of up to 1-2 kilometres, and with the thickness from few metres to 5-10 metres;

2) the metasomatic ones according to the carbonatic rocks, which are characterized by the layers with irregular shape and significant sizes, but with worse quality of the ores;

3) the deposits of the weathering, namely, the eluvial and diluvial placer deposits of the barite ores, which form themselves on the account of the destruction of the bedrock deposits; the depositions have large sizes, the ores are characterized by the low content of barite (15-20%), but are easily beneficiated.

There are known also the sedimentary and volcanogenic-sedimentary deposits. There acquire the ever increasing importance the tabular stratiform deposits of the both complex and barite proper ores.

Within the USSR, there prevail according to the reserves (92%) and extraction (99%) of barite the deposits of the complex barite ores of the hydrothermal and volcanogenic-sedimentary types, which are developed mainly within Kazakhstan. These deposits are operated with the obtainment of the flotation barite concentrate for the needs of the petroleum and gas extracting industry. The deposits of the barite ores proper are represented mainly by the hydrothermal veinous ones, which are developed within Kazakhstan and Georgia. The latter ones are operated with the obtainment of the lump barite and gravity concentrate for the chemical industry. The content of barite within the ores ranges from 20-50 to 90 % and more. Usually this content does not satisfy the requirements of the industry; for the increasing of the content of barite, and for the decreasing of the content of the harmful impurities, the ores are subjected to beneficiation by the methods of flotation, gravity, manual ore sorting, and washing. As the result, they obtain the marketable barite concentrate. The main consumer of the barite concentrate is the petroleum and gas extracting industry, which utilizes it as the weighting substance for the argillaceous drilling fluids during the drilling of the wells. The major requirements for the product for these purposes are the high density (4000-4200 kilograms per cubic metre), which depends mainly on the content of barite (its density is 4300-4500 kilograms per cubic metre). According to the GOST 4682-74 standard, there is used as the weighting substance the barite concentrate of the B class of all marks, with the content of the barium sulfate of 80% and more, and the content of the water soluble salts not more than 0.25-0.45%. Within the chemical industry, for the manufacturing of the lithopone and salts of barium, and also of the glass for the electrical vacuum devices, there is used the barite concentrate of the A class of the KB-1 and KB-2 marks, and for the lithopone also of the KB-3 mark with the content of the barium sulphate of 90-95% and more, of the silica not more than 1.5-2.5%, of the iron sesquioxide not more than 0.5-1.5%, of the sum of the oxides of calcium and magnesium not more than 0.5-1.5%. Within the cement industry and the industry of the construction materials, there is used the barite concentrate of the lower marks: KB-4, -5, -6.

The worldwide reserves of barite are estimated at 185 million tonnes (at the start of the 1980-ies, without the socialistic countries); of them 75 million tonnes are within the USA, where the reserves are mainly (%) enclosed within the stratiform (46), veinous (32), and residual (22) deposits; 10 within India, 7 within the West Germany, 6 within Ireland, Morocco, Mexico, and Algeria each, 5.5 within Thailand, 5 within Italy.

The origin of the barite industry belongs to the middle of the 19-th century. The volume of production of barite at those time was negligible. Barite was used exclusively within the production of laquers and paints. During the 20th century, with the development of the petroleum industry, the extraction of barite within the world rapidly increases. Barite is extracted on the industrial scales within the 40 countries. The production of barite is most developed within the USSR and the USA. During the 1980, there has been extracted within the world more than 5 million tonnes of barite (without the USSR). According to the extraction of barite (1981, thousand tonnes), the developed capitalistic and developing countries distribute themselves in the following manner: USA (2177), India (363), Peru (318), Mexico (318), Ireland (318), Morocco (272), Italy (227), Thailand (227), West Germany (136), Canada (91).