Outokumpu Oy

Heikki A Tiitinen

Jussi K Rastas

Tom O Niemi

Matti J Hamalainen

Kauko J Karpale

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

Cobalt is recovered as a finely-divided and anhydrous salt from impure, nickel-bearing, aqueous solutions of cobalt, by exposing the aqueous solution to oxidation at an elevated temperature in the presence of ammonia and the respective ammonium salt, the formation of cobalt (III) hexammine ions is catalysed with activated carbon or solid sulfides, a cobalt (III) hexammine salt is crystallized from the solution, the salt is separated from the solution and pyrolysed to form a cobalt (II) salt, and the released ammonia is returned to the oxidation stage.

Process for the recovery of cobalt from its impure, aqueous, in

Extra fine cobalt powder is manufactured by pyrolysing a cobalt (III)hexammine salt and then reducing the obtained oxide.

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Ulvila, Finland

Heikki A Tiitinen