Operating Experiences With A Pilot Plant For the Electrowinning of Nickel From All-Chloride Electrolyte

CIM Bulletin, Vol. 70, No. 782, 1977

L R. Hougen, Director, Metallurgy & Research, Falconbridge Nikkelverk A/S, Kristiansand, Norway., R. Parkinson, Senior Group Leader, Products Group, Falconbridge Metallurgical Laboratories, Thornhill, Ontario., J. Saetre, Research Engineer, Falconbridge Nikkelverk A/S, Kristiansand, Norway., G. Van Weert, Manager, Process Metallurgy, Falconbridge Metallurgical Laboratories, Thornhill, Ontario.

The Falconbridge Matte Leach Process yields high-purity nickel chloride by selectively dissolving nickel from copper-nickel converter matte with hydrochloric acid, purifying the solution by solvent extraction and crystallizing NiCl^4H2O by further acidifying the purified leach liquor. In the Kristiansand Matte Leach Plant, a granular oxide is produced by high-temperature hydrolysis of the nickel chloride for subsequent reduction to a high-purity granular metal product, designated NICKEL 98. This paper describes the investigation of an alternate route to processing nickel chloride in which high-quality cathode nickel is produced by electrowinning from all-chloride electrolyte. The investigation was made in a pilot circuit containing two production-size electrowinning tanks operated in conjunction with the commercial-scale leach plant.
Keywords: Hydrometallurgy, Electrowinning, Nickel, Chloride electrolytes, Falconbridge Matte Leach Process, Copper-nickel converters, Converter matte, Leaching.