A new method for recovering valuable metals from low-grade nickeliferous oxide ores

A new method, the concentrated sulfuric acid acidolysis and water leaching (SAWL) of nickeliferous oxide ores, is proposed and the optimal conditions for recovery of nickel, cobalt and copper from a low-grade Chinese nickeliferous oxide ore are presented. A series of experiments were conducted which examined the effect of acid charge, acid curing temperature and acid curing time. Recoveries of up to 95%, 83% and 95% for Ni, Cu and Co, respectively were obtained with only the sulfuric acid at ambient temperature and atmospheric pressure. Comparing the percolation leaching with agitation leaching showed that percolation leaching was capable of extracting the valuable metals with water. The SAWL method was scaled to three-stages counter-current leaching tests using 1 kg of ore. The results indicate greater than 90% extraction for nickel and cobalt.