Abstract: A method is disclosed for converting an arsenic-containing waste product to a depositable, substantially arsenic-free form by fuming-off the arsenic content thereof. The method comprises melting the waste product under oxidizing conditions in a furnace to form an oxidic slag melt; causing turbulence of the melt, while maintaining a reducing atmosphere supporting the formation of arsenic (III) oxide at the furnace temperature driving-off arsenic content of the waste product substantially in the form of gaseous arsenic (III) oxide; separating the formed oxide by condensation and recovering the same and removing from said furnace a substantially arsenic-free depositable slag.

Abstract: PCT No. PCT/SE78/00030 Sec. 371 Date Apr. 19, 1979 Sec. 102(e) Date Apr. 12, 1979, PCT Filed Aug. 11, 1978 PCT Pub. No. WO 79/00104 PCT Pub. Date Mar. 8, 1979.A method of producing blister copper from raw material containing antimony. The invention is characterized in that a slag is separated from copper matte formed by smelting the raw material. Thereafter the matte is brought into contact, under violent agitation preferably in a rotary converter of the Kaldo type, with a substantially inert gas in a quantity sufficient to reduce by volatilization the antimony content of the copper matte and, possibly, also the content of other impurities such as bismuth, arsenic and zinc to a level acceptable when performing the subsequent converting process, so as to obtain the desired blister copper product, preferably a maximum content of antimony, 0.04 percent by weight and of bismuth 0.03 percent by weight. The rotary converter is suitably operated with a rotation corresponding to a peripheral speed of approximately 0.

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.

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.