Abstract: A process for the treatment of complex metal sulphide materials and for the recovery of metal values from such materials. The process involves first subjecting the material to a leaching process under conditions such that sulphide-sulphur is oxidized to sulphate and such that oxidized iron and impurities such as As will pass into solution, whereafter the leaching residue is melted for conventional pyrometallurgical recovery of the metal values.Different embodiments of the process provide for the recovery of precious metal values from refractory materials containing such values and for the recovery of metal from complex copper concentrate and complex nickel concentrate.

Abstract: A method and apparatus for treating zinc concentrates in order to recover zinc. The method includes an oxidizing and smelting stage (10) and, subsequent to the smelting stage, a fuming stage (20) in which the zinc-oxide-containing slag formed in the smelting stage is so reduced as to remove the metallic zinc with the exhaust gases (28). Part of the reduced slag is discharged during the fuming stage, another part (32) is recirculated to the smelting stage. In accordance with a preferable method, the slag is reduced in two successive fuming stages (20, 40). In an apparatus according to the invention, the slag circulation between the fuming and smelting stages is facilitated by overflows arranged in the partition walls (19) between the various stages.

Abstract: A catalyst bed for conducting exothermal reactions between gases and/or other fluids is disclosed. The catalyst bed includes at least two cooling elements arranged in parallel relationship with each other. A space is thereby defined between the two cooling elements, and one opening at each opposite end of the cooling elements is also defined by the arrangement of cooling elements. The space created is adapted to receive a catalyst mass through either of the openings. The cooling elements cool the gases and/or other fluids, as well as the catalyst mass to keep the reaction temperature low enough to maintain a desired state of equilibrium.

Abstract: A method and apparatus for treating zinc concentrates in order to recover zinc. The method includes an oxidizing and smelting stage (10) and, subsequent to the smelting stage, a fuming stage (20) in which the zinc-oxide-containing slag formed in the smelting stage is so reduced as to remove the metallic zinc with the exhaust gases (28). Part of the reduced slag is discharged during the fuming stage, another part (32) is recirculated to the smelting stage. In accordance with a preferable method, the slag is reduced in two successive fuming stages (20, 40). In an apparatus according to the invention, the slag circulation between the fuming and smelting stages is facilitated by overflows arranged in the partition walls (19) between the various stages.

Abstract: The invention relates to a method for producing metallic lead from lead-containing starting materials by an oxidizing smelting process and subsequent reduction of the resultant oxidic molten bath. The reduction is effected with solid carbonaceous reduction agent present in the melt, and it is ensured that solid carbonate-containing material, preferably limestone, dolomite or soda ash, is also present in the melt, together with the reduction agent.The method can be applied for working-up lead-starting materials of sulphidic, oxidic or sulphatic kind. In addition, the method can be applied to advantage for working-up lead-carbonate containing starting materials, where at least a part of the carbonate-containing material may comprise lead-starting material.

Abstract: The invention relates to a method for recovering the metal values from materials containing at least one of zinc and tin, by smelting the starting materials under oxidizing conditions and reducing the resultant molten bath. The starting materials are first smelted in a furnace while adding flux, to form a slag which is sluggish at selected reduction temperatures and has a low lead contents. The reduction process is carried out while charging solid carbonaceous reduction agent and optionally also sulphur- and/or chlorine-donor material to the slag. The reduction agent and optionally supplied donor material is brought into suspension with the slag, and this suspension is sustained at least during the latter phase of the reduction period, at which the lead content of the slag has fallen to beneath about 1-2%, during which phase the reduction of zinc and tin takes place.

Abstract: A method for manufacturing sulphur-trioxide for the production of sulphuric acid from sulphur-dioxide containing gas, particularly furnace gas obtained from metallurgical processes by oxidation to sulphur trioxide in the presence of a catalyst and conversion of the sulphur trioxide to sulphuric acid. The sulphur dioxide is first separated from the gas preferably converted to liquid form and is then subsequent to being vaporized in a stoichiometric excess oxidized with oxygen.

Abstract: The invention relates to a method for producing blister copper from copper-iron sulphide concentrates, and particularly from concentrates whose sulphur content is insufficient to effect autogenous smelting of the concentrates to matte. The invention is characterized in that the concentrate, together with slag former, is smelted with oxygen-gas or air rich in oxygen in a top blown rotary converter, to form a mixture of a contaminated copper metal phase, magnetite and fayalite slag, whereafter a reductant, preferably coke, is supplied for the reduction of magnetite while supplying heat. After the reduction process, the slag is separated from the formed copper metal phase, which is then refined to blister copper in a manner known per se.

Abstract: The invention relates to a method for producing lead from sulphidic lead raw-materials by direct smelting processes of the kind in which the lead raw-materials are smelted autogenously in a shaft with the aid of oxygen gas, or air enriched in oxygen, optionally by adding fluxes, there being formed an oxide-containing molten product which is caused to pass into a coke bed arranged in the lower part of the shaft, to form a lead phase and a slag depleted in lead. The invention is characterized by heating the coke bed continuously, by partially combusting carbon therein and/or by supplying electrical energy thereto.The electrical heating is preferably effected by supplying electrical energy through induction or through electrodes.When heating the coke bed by the partial combustion of coke in the bed, oxygen gas or air enriched in oxygen is preferably introduced directly into the coke bed, through tuyeres or lances.

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: The invention relates to a method for producing fuel from solid bituminous or lignocellulosic material. The material is charged, optionally continuously, to a closed vessel together with oil heated to a temperature in excess of 65.degree. C., preferably in excess of 75.degree. C. A total gas pressure of 5-50 kPa is maintained in the vessel. The material and oil are removed from the vessel, optionally also continuously, and separated by mechanical means, for example by means of rolls, to press the oil from the material. The separated oil is returned to the process.

Abstract: Lead is recovered from sulphidic lead raw-material containing impurities of the kind bismuth, arsenic, antimony and tin, by flame-smelting the material with an oxygen-containing gas. The oxygen potential and temperature are adapted during the flame-smelting process so that the product formed thereby comprises substantially a lead-sulphide melt substantially free of volatile, sulphidic and metallic impurities of the said kind. The lead-sulphide melt is brought into contact with an oxidic lead material substantially free of impurities of the aforementioned kind, while oxidizing the sulphide-sulphur content of the material and forming a melt substantially free of sulphur. Lead is recovered from the melt by separation, optionally after subjecting the melt or a part thereof to a reducing process.

Abstract: The metal content of complex sulphidic metal raw material is recovered therefrom by means of an autogenous flame-smelting process, preferably carried out in a vortex, with an oxygen-containing gas. The raw materials are smelted in a furnace in the presence of an excess of oxygen and together with an addition of an acid slag former, such as silica, to form a melt which is rich in metal-oxide silicate and poor in sulphur. Any metal phase formed in the furnace is separated from the silicate phase, and non-iron metals present in the silicate phase are recovered therefrom by selective reduction.

Abstract: A method is provided for directly heating a concentrated sulphuric-acid solution by passing alternating electric current between surface-passivated electrodes immersed in the solution and by using electrodes of iron or an iron alloy having a low resistance iron or iron alloy inner core covered by an outer high resistance passivating surface layer which are so surface-passivated that the transition resistance between the electrodes and the concentrated sulphuric-acid solution is at least as great as the resistance exerted by the concentrated sulphuric-acid solution.

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.