Outokumpu Oy

Other

Kauko J Karpale

Jussi K Rastas

Alan W Weimer

Stephen D Dunmead

Jacob A Johnson

Heikki A Tiitinen

Karen J Buechler

Lars-Goran Bjorkqvist

Jens R Nyberg

A method of converting metal-containing or metal alloy-containing compounds into a metal or metal alloy by rapidly heating the metal-containing or metal alloy-containing compound to an elevated temperature to instigate conversion and holding the metal-containing or metal alloy-containing compound at the elevated temperature for a time sufficient to effect formation of the metal or metal alloy is an efficient and economical method of producing metals and metal alloys.

Rapid conversion of metal-containing compounds to form metals or metal alloys

A process for the recovery of valuable metals from roasted crude-oil sulfur-extraction catalyst waste is disclosed. In this process the value metals can be separated from aluminum in a single stage by treating the waste at elevated temperature and pressure with such an amount of sulfate solution that the waste dissolves and the aluminum simultaneously precipitates as alunite, which is separated from the solution which contains the other value metals. A sulfate solution is preferably added in such an amount that the concentration of sulfuric acid in the solution is 2-30 g/l at the end of the stage.

Process for the recovery of valuable metals from spent crude-oil

A hydrometallurgical process for the treatment of a raw material which contains oxides and ferrites of zinc, copper and cadmium is disclosed, wherein the raw material is neutral leached by means of a sulfuric-acid-bearing solution to leach the oxides without substantial dissolving of the ferrites, a ferrite-bearing residue is separated, and a sulfuric-acid-bearing or ferrisulfate-bearing solution is mixed with the residue in order to leach the ferrite and to precipitate the iron in the form of jarosite in the presence of alkali or ammonium ions under atmospheric conditions at 80.degree.-105.degree. C., and the solid phase is separated from the solution. The sulfuric-acid-bearing or ferrisulfate-bearing solution is added to the ferrite-bearing residue in such an amount that approximately 50-60% of the ferrite dissolves and its iron is precipitated as jarosite, and the slurry of the solid phase is treated at such elevated pressure and temperature that the zinc of the solid phase is converted to zinc sulfate and the iron to hematite in accordance with the following reaction:

Hydrometallurgical process for the treatment of a raw material which

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Ulvila, Finland

Kauko J Karpale