Sherritt Gordon Mines Limited

Sherritt International Corporation

Russell P Kofluk

Donald R Weir

Derek G Kerfoot

Verner B Sefton

Gavin Kerry Wyllie Freeman

Ockert Gerbrandt Pauw

James John Budac

There is provided an improvement in a process for producing cobalt (III) hexammine sulphate which process comprises oxidatively pressure leaching nickel cobalt sulphides in an ammoniacal ammonium sulphate solution. The nickel and cobalt sulphides are oxidized to sulphates, and an ammoniacal leach liquor in which dissolved cobalt is predominantly in the (III) oxidation state is produced. The ammoniacal leach liquor is combined with ammonia to precipitate the triple salt of cobalt (III) hexammine sulphate, nickel (II) hexammine and ammonium sulphate which is further treated to produce a crystalline cobalt (III) hexammine sulphate and a nickel enriched leach liquor. The improvement involves the provision of a second oxidative pressure treatment effective to maximize the formation of the desired cobalt (III) hexammine ion, prior to the triple salt precipitation step.

Producing cobalt (III) hexammine sulfate from nickel cobalt sulfides

A process for separately recovering platinum group metal values, nickel values and copper from nickel-copper-iron sulphidic matte containing platinum group metals includes leaching ground matte at atmospheric pressure in acidic nickel-copper sulphate solution at a temperature in the range of from about 75.degree. to about 105.degree. C. and at a pH below about 4 initially under oxidizing conditions and subsequently under neutral or non-oxidizing conditions to cause dissolution of nickel and iron, precipitation of copper as a copper sulphide and precipitation of dissolved platinum group metals. The copper, nickel and platinum group metal containing solids are separated from the nickel and iron containing sulphate solution and are leached in acidic nickel-copper sulphate solution under pressurized oxidizing conditions at a temperature of from about 120.degree. to about 180.degree. C. to cause dissolution of nickel and copper with minor dissolution of platinum group metals. The platinum group metal containing solids are separated from the nickel and copper containing sulphate solution, and copper is electrowon from the nickel and copper containing sulphate solution under conditions to cause cathodic deposition of copper without significant deposition of nickel. Spent nickel and copper containing electrolyte solution which also contains minor amounts of dissolved platinum group metals is recycled to the atmospheric leach and pressure leaching steps.

Recovery of platinum group metals from nickel-copper-iron matte

A process for separately recovering nickel and cobalt from solution includes adjusting the pH of the solution to a value between about 3 and about 6, and then contacting the solution with a chelating ion exchange resin having aminocarboxylic acid functional groups to selectively load nickel onto the resin to produce a nickel loaded resin and a nickel depleted cobalt containing solution. The process is also applicable to the separate recovery of copper and zinc from solution.

Selective recovery of nickel and cobalt or copper and zinc from solution

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Opal, Canada

Russell P Kofluk