Boliden Aktiebolag

Boliden Mineral Ab

Stig A Petersson

Bengt S Eriksson

Bjorn K Lindquist

Torsten E Jensfelt

Leif Johansson

Bengt O Rudling

Allan F Norro

Ake Sandstrom

Arne C Fridfeldt

Ulf C Waara

Method for processing complex metal sulphide materials

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.

Method for producing metallic lead by direct lead-smelting

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. Zinc is recovered from the furnace in the form of zinc vapor, while tin optionally is removed as volatile tin sulphide, chloride or oxide, and lead and any other metal values present in the starting materials are recovered as a molten lead phase.

Method for recovering the metal values from materials containing tin

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.

Method of manufacturing sulphur-trioxide for the production of sulphuric

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. In this respect, a preferred method of refining the copper metal phase, or black copper, is to refine the black copper, subsequent to separating the slag, in the converter by an oxidizing process with the addition of a further slag former, to form blister copper and a slag containing oxidized impurities from the ingoing copper metal phase.

Method for producing blister copper

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.

Method of producing lead from sulphidic lead raw-material

Method for working-up arsenic-containing waste

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.

Method for producing a fuel from solid bituminous and/or lignocellulosic

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.

Manufacture of lead from sulphidic lead raw material

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.

Method for recovering the metal content of complex sulphidic metal raw

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.

Method for directly heating concentrated sulfuric acid by electric

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 0.5-7 m/s, preferably 2-5 m/s.

Method of producing blister copper from copper raw material containing

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.

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Skelleftehamn, Sweden

Stig A Petersson