Brazilian nickel-bearing province
BRAZILIAN NICKEL-BEARING PROVINCE (RU: Бразильская никеленосная провинция) is the group of the nickel deposits within Brazil, within the Goias, Minas Gerais, Piauí, and São Paulo states. The reserves of the ore are 317 million tonnes (1977; the average content of Ni is 1.6%). The major deposits are: Barrio Alto (the reserves are 40 million tonnes, the content of Ni is 1.9%), Morro do Ingenue (40 million tonnes, the content of Ni is 1.12%), Nickelandia (20 million tonnes, the content of Ni is 1.7%), and Oko, within the Goias state (74% of the total reserves of nickel within the country); Morro do Corsica, Liberdade, Livramento, Ipanema, Ipatinga, within the Minas Gerais state (19% of the total reserves); and San Jose within the Piaui state (7% of the total reserves). The silicate nickel ores have been discovered for the first time at the Liberdade during the 1915. The development of the Liberdade deposit, and the production of ferronickel from its ores, have been started during the 30-ies. The discovery and exploration of all other deposits within the province belong to the 2nd half of the 20th century. The geological-exploratory works are conducted most intensively since the start of the 70-ies.
The Brazilian nickel-bearing province is confined to the Cenozoic crust of the weathering on the massifs of the Mesozoic ultrabasic rocks within the limits of the Brazilian highland. The crust of the weathering has the kerolite-goethite profile with the thickness of 10-60 metres, which is comprising the upper (ochres) and lower (leached serpentinites) zones. The zone of the ochres amounts to approximately half the eluvial stratum. At all the deposits, the industrial concentrations of nickel are characteristic for the zone of the leached serpentinites, and for the lower part of the zone of the ochres, which is overlying the first zone. The ores consist of goethite, hydrogoethite, hydrohematite, maghemite, asbolane, kerolite, leached serpentine, and hydrosilicates of nickel. The nickel kerolite and garnierite form the largest concentrations within the lower horizons of eluvium. The serpentinites, which are underlying the eluvial stratum, and are slightly influenced by the weathering, are usually replete with the venules of the nickel kerolite and of the nickel serpophite.
Till the middle of the 70-ies, the extraction of the nickel ores was conducted by the "Mineração Morro do Niquel C. A." actually only at the two deposits within the Minas Gerais state (279 thousand tonnes of the ore, or 5.3 thousand tonnes of nickel, during the 1976). During the 2nd half of the 70-ies, there has been started the development of the Barro Alto deposit by the "Bamin Co. Mineração e Siderurgica" company. During the end of the 1980, the production of the metallic nickel (3.1 thousand tonnes) satisfied the requirements of the country for approximately 50%.
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