Corrosion Experiences 1n the Acid Leaching of Cobalt-Nickel Sulphides

A brief description is given of the process used by Sherritt Gordon Mines Limited to recover cobalt metal from nickel-cobalt sulphides. A description of the equipment with the operating conditions is presented with an evaluation of the corrosion test results for various stainless steels and other acid resistant materials for the part of the process involving the sulphuric acid leaching of nickel-cobalt sulphide slurry under air pressure. SINCE 1954 the Sherritt Gordon ammonia leach process has been used at Fort Saskatchewan to recover nickel metal, copper sulphides and cobalt-nickel sulphides from nickel concentrate produced at Lynn Lake, Manitoba. 'To develop a process for recovering cobalt and nickel from the cobalt-nickel sulphides, studies were carried out in the Sherritt Gordon laboratory and pilot plant and, late in 1957, continuous acid leaching of sulphides was started in the refinery. In September 1958 the present equipment