Direct solvent extraction of nickel at Bulong operations

Abstract

Bulong Operations processed a nickel laterite resource 30 km east of Kalgoorlie, Western Australia, between April 1999 and October 2003. The Bulong refinery operated a direct solvent extraction process to recover nickel cathode from dilute leach liquor without the need for precipitation of an intermediate nickel product. Before closing due to financial pressures, the Bulong refinery experienced significant modification and optimisation of the solvent extraction circuits. These modifications improved metallurgical performance to a level meeting or exceeding most design parameters and this paper documents the metallurgical performance of the Bulong direct solvent extraction process at the time of plant closure. The solvent extraction process was capable of producing a nickel electrolyte suitable for electrowinning >99.8% nickel cathode, and a concentrated cobalt liquor suitable for recovering a saleable cobalt product. Typical nickel and cobalt recoveries from PLS to product liquors were 98.2% and 98.5%, respectively.