Bangka

BANGKA (EN: Bangka, Banka; RU: Банка) is the tin ore region on the Bangka island within Indonesia. It is being developed since the 1709. The tin mineralization is associated with the acidic Mesozoic granites, which are breaching the sandy-schistose strata of the Permian - Carboniferous and Triassic.

There are known on the Bangka island the 20 bedrock deposits, which are situated within the contact zones of the granitic massifs, and are represented by the cassiterite-containing quartzous and quartz-feldspathic veins and stockworks within the granites, which are accompanied by the tin-bearing zones of greisenization (the Pemali, Baley-Bandeng, Sambongiri, and other deposits). The bedrock ores are not being developed; the major extraction of tin is conducted from the placer deposits, namely, eluvial, alluvial, and littoral ones. The placer deposits are orderly, of the comparatively simple morphology and homogeneous lithological composition; they represent by themselves mainly the re-washed crust of the weathering of the granites. The content of tin within the productive horizon ("sands") with the thickness of 0.5-2 metres, which has the "kaksa" local name, is 2-15 kilograms per cubic metre; the content of tin within the ore mass, which is being extracted, within the placer deposits varies from 150 to 700 grams per cubic metre. There prevail the dredging and hydraulic methods of development. During the time of the operation of the deposits of the Bangka island, there have been extracted more than 1 million tonnes of tin (in terms of metal). The annual production of the tin concentrates (with the content of Sn of approximately 40%) is 19.3 thousand tonnes of the primary metal (1980), which amounts to 2/3 of the total extraction of tin within Indonesia. Bangka is the raw materials base of the tin smelting plant within the Mentok (Muntok) city (on the Bangka island).