Witbank

WITBANK (EN: Witbank; RU: Витбанк) is the largest mineral coal basin within the Republic of South Africa. This basin is situated within the Transvaal (the large part), Natal, and Orange provinces. The length is approximately 550 kilometres. The area is more than 55 thousand square kilometres. Within the region of the Breyten city, the deposits of the coal are known since the 2nd half of the 19th century. During the 1887, the deposits of the coal have been uncovered within the region of the Sprints city; the start of their industrial developments belongs to the 1890, which fact is associated with the development of the extraction of gold and diamonds. The broad industrial mastering has been started during the 1st half of the 20th century, and especially intensively during the 70-ies of the 20th century. The total reserves of the coal are more than 51 billion tonnes (including 908 million tonnes of the coking coals, and 744 million tonnes of the anthracites), the explored reserves are more than 25 billion tonnes (including 395 million tonnes of the coking coals, and 118 million tonnes of the anthracites).

The Witbank basin is sub-divided into the following coal-bearing regions: Firfonteyn, Vereeniging, South Rand, Witbank-Middelburg, Highveld, Utreh, Klipp, Vryheid. Approximately 60% of the coal, which is consumed within the Republic of South Africa, is extracted within the Witbank-Middelburg region. There are being developed approximately 60 deposits with the extraction of more than 2 million tonnes per year, including (there is within the brackets the annual planned extraction, million tonnes); Bossiespruit (12.0), Duvha (10.1), Matla (10.0), Douglas (9.0), Creel (8.5), Witbank (8.0), Usutu (6.0), Optimum (6.0), Kleynkope (5.5), Rietspruit (5.0). The large quantity of these deposits belongs to the large companies and consortia: "Anglo-American Corporation of South Africa", "General Mining and Finance Corporation", "Rand Mines", "South Africa Oil and Gas Corporation", "Johannesburg Consolidated Investment". The Witbank basin is situated within the north-eastern part of the Karoo s yncline, within the region of its junction with the Transvaal massif. The industrial coal-bearing capacity is associated prevalently with the sandstones of the Middle Eck stratigraphic suite (120-390 metres) of the Lower Permian age (the Karoo series). The embedment of the coal-bearing depositions is almost horizontal, slightly undulated within the certain places, is complicated with the ruptures with the amplitude of 10-100 metres, which are creating the block structure; within the certain places, these depositions are intruded with the dikes and sills of the dolerites (especially within the southern part of the basin). There are contained within the coal-bearing stratum up to 5 coal layers, of which there are being developed the 1-4 layers; the coal layers usually have the complex structure; their thickness is 0.6-9 metres. The average depth of the embedment is approximately 70 metres (80-150 metres within the Witbank-Middelburg region).

The coals of the basin are mostly energetical, and rarely coking. The coals are metamorphosed prevalently to the gas and long-flame stages (at the south of the basin, because of the impacts from the dikes and intrusions, to the anthracite stage). The ash content is 6.9-34.9% (approximately 20% on average). Approximately 45% of the coals require the beneficiation. The coals with the greatest ash content are located within the western part of the basin, the coals with the least ash content (prevalently the anthracites) are located within the southern part of the basin. The yield of the volatile substances is 6.1-33.7% (21.4-33.1% for the coking coals, 6.1-12.6% for the anthracites), the content of sulfur is 0.4-1.8%, the heat of combustion is 17.3-32.0 megajoules per kilogram.

The coal is being developed mostly using the underground method, there is used at the underground mines the room and pillar system for the development, with the usage of the short-stope combined cutting-loading mining machines, and of other means for mechanization; at the 20% of the extracting enterprises, the excavation of the coal is performed manually. At the new underground mines, there is used the longwall stope system for the development, and there are being introduced the highly mechanized complexes. 15-20% of the coal is extracted using the opencast method; there work the following open-pit mines: "Optimum", "Kleynkope", "Rietspruit", "Duvha". At the stripping works, there are used the draglines. By the 1985, there is expected to increase the share of the coal, which is extracted using the opencast method, up to 30-35%. The annual extraction within the basin has increased from 38 million tonnes (1960) to 100 million tonnes (1979).

The main consumers of the coal (1980) are the thermal power stations (approximately 52 million tonnes), the metallurgical industry (9 million tonnes), the enterprises for the obtainment of the "Sasol" artificial fuel (approximately 11 million tonnes), and the railroads (approximately 2.2 million tonnes). The coal, which has been extracted, is exported through the Richards Bay port, which is connected with the main coal extracting regions using the railways with the length of approximately 500 kilometres, into the France, Japan, Italy, West Germany, USA, and Israel. During the 1980, there has been exported more than 28.5 million tonnes.

On the territory of the basin, there are known the numerous deposits of various useful minerals, including the ores of gold, iron, and polymetals.