Amax Incorporated

Luther R Tinnin

Ranko P Crnojevich

Edward I Wiewiorowski

Leo W Beckstead

Eddie C Chou

Fine cobalt or nickel powder is produced by hydrogen reduction of a sulfate solution in the presence of a base and a strong reductant such as a metal borohydride wherein the base is added stagewise to the solution with the initial addition of base being sufficient to insure an essentially neutral pH at the time of reductant addition.

Production of cobalt and nickel powder

Metal values and alumina are recovered from spent, usually oily, catalysts by oxygen pressure leaching with sodium hydroxide and/or sodium aluminate to dissolve molybdenum, vanadium and/or tungsten and provide a solid, filterable residue containing alumina and cobalt and/or nickel, the residue is digested with sodium hydroxide to give a sodium aluminate solution and a residue enriched in nickel and/or cobalt, alumina is recovered from the sodium aluminate solution as a solid and the remaining supernatant solution is recycled to the oxygen pressure leaching step wherein the alumina content of the aluminate solution is precipitated and a bleed for metals in the aluminate solution is provided.

Cyclic process for recovering metal values and alumina from spent

A method is provided for decreasing the silicon content of relatively pure nickel and/or cobalt powder, wherein silicon is present as an impurity substantially in the oxidic state. The method comprises mixing the metal powder in an aqueous solution of an alkali metal hydroxide, e.g. sodium hydroxide, with the temperature of the solution ranging from ambient to below boiling and maintaining the powder in contact with the solution until the silicon content of the powder has been reduced to the desired level.

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New Orleans, LA, United States of America

Luther R Tinnin