Inco Limited

Cytec Technology Corporation

Vale Inco Limited

Bruce John Love

Eberhard Krause

Avinash Singhal

Derek George Eagland Kerfoot

William A Rickelton

Indje O Mihaylov

Pak Kuen Louie

A hydrometallurgical process for the recovery of nickel and cobalt values from a sulfidic flotation concentrate. The process involves forming a slurry of the sulfidic flotation concentrate in an acid solution, and subjecting the slurried flotation concentrate to a chlorine leach at atmospheric pressure followed by an oxidative pressure leach. After liquid-solids separation and purification of the concentrate resulting in the removal of copper and cobalt, the nickel-containing solution is directly treated by electrowinning to recover nickel cathode therefrom.

Hydrometallurgical process for the recovery of nickel and cobalt values from a sulfidic flotation concentrate

The invention provides a method of regenerating dithiophosphorus extractants such as dithiophosphoric acids, dithiophosphonic acids and dithiophosphinic acids from their sulfur-sulfur bonded oxidation products contained in an organic solution. The process generates active hydrogen for regenerating the spent dithiophosphorus extractants. Advantageously, this active hydrogen originates either from introducing a reactive metal into a liquid mixture containing the organic solution and an acidic aqueous solution to form nascent hydrogen or from using hydrogen gas in the presence of a catalyst in the organic solution. The active hydrogen generated in the process breaks the sulfur-sulfur bonds of the dithiophosphorus molecules to form the corresponding dithiophosphorus acids.

Regeneration of dithiophosphorus acid metal extractants

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Georgetown, Canada

Bruce John Love