Research on Leaching of Cobalt From White Cobalt Alloy by Mechanical Activation

Leaching of cobalt from white cobalt alloy using sulfuric acid by mechanical activation was studied.The effects of activation time,leaching temperature and sulfuric acid concentration on leaching of cobalt using air as oxidant in H2SO4 medium were examined.The results show that leaching of cobalt increases with activation time,leaching temperature and sulfuric acid concentration.Mechanical activation could improve leaching of cobalt bacause particles became smaller,specific surface energy increase.Under the conditions of sulfuric acid concentration of 3mol/L,temperature of 80 ℃,liquidto-solid ratio of 8∶1,air flux of 4L/min,leaching time of 12 hand stirring rate of 150r/min,the leaching rate of cobalt is 96.1% and 63.2% for activating 60 min and unactivating samples,respectively.