Research on Selective Leaching of Cobalt White Alloy from Weakly Acidic Solution

Valuable metals were selectively leached from cobalt white alloy by using air as oxidant in diluted hydrochloric acid system.Continuous leaching tests were conducted under the following optimum leaching conditions: at a reaction temperature of 85 ℃,with solid-to-liquid ratio of 1∶10,agitation speed of 1 000 r/min and leaching time of 12 h,with a 15% excess of system acid,an air flux of 4 L/min,and the dosage of additive NL being 4%(relative to cobalt white alloy).Results showed the leaching rate of Co,Cu and Ni reached up to 95.27%,95.14% and 94.28%,respectively.