Abstract: The present invention relates to a method of operating a converter, in particular a Peirce-Smith converter or a converter with similar design or mode of operation, and to an apparatus, for instance a plant, for carrying out the method. The method comprises the step of: loading the converter with a starting material comprising said metal, the metal in the starting material being chemically bound at least in part to at least one compound substance, in particular sulphur; maintaining a temperature within the converter interior space, which is above the melting temperature of the starting material; and supplying an oxygen-containing process gas into the converter interior space through injection nozzles arranged in the wall of the converter, the gas supplied through the injection nozzles comprising carbon dioxide, preferably very cold, technically pure carbon dioxide, as well as oxygen gas and/or air.

Abstract: A method of processing flue dust, where the flue dust contains one or more compounds from a first group of zinc, lead and cadmium compounds, and contains one or more compounds from a second group of iron, silicon, calcium, magnesium and aluminum compounds, includes mixing the flue dust with a carbonaceous material, heating the flue dust/carbonaceous material mixture under non-turbulent conditions to cause a substantial portion of the compounds from the first group to become gas-borne while retaining a substantial portion of the compounds of the second group in a non-gas-borne condition, and separating the gas-borne compounds from the non-gas-borne compounds.

Abstract: A process for recovery of substantially all the sulfur in a spent lead-acid battery as Na2SO4 is disclosed. The process comprises (a) breaking the batteries to remove the acid, (b) separating the plastic from the lead bearing materials, (c) smelting the lead bearing materials in a reverberatory furnace in an oxidizing atmosphere to volatilize most of the sulfur in the feed as SO2, (d) scrubbing the SO2 from the off gas stream using a soluble alkaline material such as NaOH, Na2CO3, or KOH to produce a soluble sulfite solution, (e) oxidizing the sulfite solution to sulfate, preferably by turbulent mixing of the solution with air, (f) adjusting the pH by adding the sulfuric acid separated from the batteries, (g) removing the contained heavy metals, (h) crystallizing the sulfate as Na2SO4 or K2SO4, (i) separating a bleed stream from the crystallizer and removing the contained chlorides as a mixed sulfate-chloride product by evaporation of the bleed stream in another crystallizer.

Abstract: Copper and or nickel sulfide ore concentrates of high intrinsic value are oxygen smelted by introducing such concentrates via feeds (32) into a closed loop extraction circuit in which a molten sulphide carrier composition is forcibly circulated by an R-H unit (14) through lower hearth (10) at which feed of the concentrates takes place, and upper hearth (12) at which controlled oxidation with technically pure oxygen through top lances (4) takes place to oxidize copper sulphide and iron sulphide in the concentrate to iron oxide. Copper is removed via line (42). Slag containing iron oxide is discharged via weir (22) into a secondary circuit in hearths (24 and 28). Carbonaceous reductant added to the slag in (28) reduces the iron oxide in the slag to hot iron product.

Abstract: An electric furnace (containing an immersed electrode) and a process for the recovery of lead, arising especially from solid residues. Fines, which are a product of physically crushing spent batteries, are melted under not very reducing conditions in the presence of a small amount of carbon. This melting allows separating the crude lead and the lead-rich slag so as to remove sulphur in the form of sulphur dioxide and to optionally recover the crude lead. The lead-rich slag is then reduced with a suitable amount of carbon so as to separate the lead-free slag and the crude lead, which again can recovered.

Abstract: The invention relates to a method for producing zinc, cadmium, lead and other easily volatile metals from sulfidic raw materials in a pyrometallurgical process. In the method, zinc sulfide concentrate is fed into molten copper in atmospheric conditions, at a temperature of 1,450.degree.-1,800.degree. C., so that the zinc, lead and cadmium are volatilized, and the iron and copper remain in the molten metal or in the metal sulfide matte created in the furnace.

Abstract: A process for treatment of zinc sulfide or other zinc bearing feed materials in conjunction with an iron sulfide containing mineral or compound to effect a separation of zinc from iron by fuming on either zinc and sulphur vapor or zinc sulphide vapor. The vapor is stripped and transported by a carrier gas from the mineral or a molten matte formed from the mineral. The process is operated at a temperature in the region of 1250.degree. to 1400.degree. C. and at a partial pressure of oxygen in the region of 10-.sup.7 to 10-.sup.11 bar. The process is conducted in the presence of a liquid matte phase which contains at least iron sulphide and which is intimately mixed in a bath with a slag phase.

Abstract: There is proposed a process for recovering lead, comprising the steps of: feeding molten caustic soda, lead-containing feed and an oxygen-containing gas into a reaction some having a temperature of 600.degree. to 700.degree. C. as a result of which there are obtained lead metal withdrawn from the process and a melt containing sodium sulphate, zinc and copper sulphides, and gangue. The melt is discharged from the reaction zone of subjected to a first leaching operation to obtain, as a result, a slurry representing a mixture of solid particles of sodium sulphate, zinc and copper sulphides, gangue and an aqueous solution containing essentially caustic soda. Further on, the slurry is filtered to produce a concentrated aqueous solution containing essentially caustic soda and a solid residue. The concentrated caustic soda solution is subjected to thickening by evaporation and the resulting caustic soda melt is fed into the reaction zone.

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 pyrometallurgical refining process for obtaining one or both of zinc and lead from a sulfide concentrate, in which an iron-silicate slag or iron-silicate slag containing lime is formed and the sulfide concentrate, incombustible materials, and flux, together with at least one of industrial oxygen, oxygen-enriched air, or air, are blown into the slag to cause a reaction; as a result of the reaction, the major part of the zinc and part of the lead in the sulfide concentrate and the incombustible materials are dissolved in the slag, to arrange the slag and a matte and/or metal from one part of the lead in the raw material. A reducing agent such as heavy oil, pulverized coal, powdered coke, or the like is blown through the resulting slag, and the zinc and the lead in the slag are volatilized then condensed to obtain molten zinc and molten lead.

Abstract: The present invention relates to a method for monitoring and control of smeltmetallurgical processes, endothermic as well as exothermic ones, preferably pyrometallurgical processes, by means of optical spectrometry, whereby one first determines for each endothermic and exothermic smeltmetallurgical process and/or process step characteristic emissions or absorptions and identifies the atomic or molecular origin of the emissions/absorptions, that one during a running process records changes in the characteristic emissions/absorptions and relates these changes to the condition of the process and with reference hereto controls the process.