Method of producing blister copper
AssigneeBoliden Aktiebolag
InventorsStig A. Petersson, Bengt S. Eriksson
Life of this patent
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Abstract
A method of producing blister copper comprising smelting sulphidic copper raw material in a rotary furnace with an inclined rotation axis, in presence of oxygen and slag formers charged simultaneously with the copper raw material. The method comprises discontinuing the oxygen charge when at least 75% of the copper raw material has been charged and treating the obtained matte and slag with a reduction agent and then transferring the matte and the slag together to a holding furnace in which the matte and the slag are separated and transferring the matte in the holding furnace to a converter where it is converted to blister copper.
Claims10
A method of producing blister copper, wherein sulphidic copper raw material is smelted to form a matte and a slag in a rotary furnace arranged to rotate about an inclined axis at a rotary speed of from about 10 rpm to about 60 rpm in the presence of oxygen and slag formers and wherein the matte is converted to blister copper, which method comprises the steps of heating the rotary furnace to a temperature of at least 900.degree. C.;
- charging simultaneously the copper raw material, slag former and oxygen to the rotary furnace to autogeneously smelt said raw material by means of heat obtained by burning sulphur contained in said raw material, so that a smelt comprising a matte having a desired copper content and a copper-containing slag is formed and maintained at a temperature of 1100.degree.-1300.degree. C.;
- treating the smelt obtained with at least one reductant selected from the group consisting of coke, coal, oil, natural gas, pyrite, chalcopyrite, pyrrhotite and additional amounts of said sulphidic copper raw material, so that the copper content in the slag is decreased;
- transferring the smelt batchwise to a holding furnace in which the matte and the slag are mutually separated;
- treating the slag in the holding furnace during its passage therethrough to further decrease the copper content in the slag to a predetermined level;
- tapping-off the matte separated in the holding furnace and transferring said matte to a converter;
- and finally tapping-off the slag thus reduced and separated.
Dependencies are inferred from the claim text.