Abstract:
A lot of oxide ore was stockpiled and left unprocessed after it was peeled from sulfide ores on the weathered layer of a large-scale copper-lead deposit in the southwest area of Yunnan Province, due to its much lower beneficiability than the sulfide ore. This oxide ore contains abundant copper, lead and silver values, respectively assaying 0.96%, 8.66% and 317 g/t grades, in which 85.58% copper and approximately 50% lead occurs in the forms of oxide minerals. However, their separation and recovery are low-efficient due to the high oxidation rate and complex mineral composition in the ore. Based on the ore properties and experimental results, it has been determined that under the condition of grinding fineness of -74 μm with 75% passing, the mixed flotation of copper and lead is enhanced by using ammonium salts. The resulting mixed concentrate is then separated into high-quality lead concentrate through gravity separation, and the gravity tailings are further processed through acid leaching to recover copper, forming a joint process of mineral processing and metallurgy. At the optimized operation conditions, a leaching solution with copper recovery of 86.25%, and a lead concentrate assaying of 66.48% lead and 2 095 g/t silver grades at 88.74% lead and 76.39% silver recoveries were finally obtained, achieving a good recovery and enrichment performance for copper, lead and silver values. This research outcome would provide a valuable reference for the economic and effective utilization of such refractory ores.