China Nonferrous Metallurgy

The stockpile quantity of the low grade refractory oxygen-sulfur mixed lead-zinc ore in Lanping mine is 38 million tons, with the grade of Zn5.73 % and Pb1.32 %. The ore is extremely complex, with low grade, high oxidation rate, large mud content and fine disseminated grain size. It is a typical refractory ore, and its utilization technology is a world-class problem. Yunnan Jinding Zinc Industry Co., Ltd. invested a large amount of experimental research funds for research on beneficiation technology, but did not achieve good results. In order to deal with the low-grade refractory oxygen-sulfur mixed ore economically and effectively, the company decided to adopt a combined process of hydrometallurgy first and then beneficiation. First, the new technology of “leaching-extraction-electrolysis” is used to treat the zinc oxide in the oxygen-sulfur mixed ore, and then the flotation process is used to treat the zinc sulfide in the leaching residue. Under the optimal leaching process conditions determined in the experiment, the recovery rate of zinc oxide is 92%, the recovery rate of zinc sulfide is 95%, and the total recovery rate of zinc resources is greater than 90%, which is 30% higher than the traditional process of beneficiation first and then metallurgy. The combined process of hydrometallurgy and beneficiation has advantages such as strong adaptability to raw materials, short process, high recovery rate, and it is a closed loop, does not produce waste water or exhaust gas, and the generated tailings are general solid wastes. Its environmental protection and economic benefits are obvious, and it is practical.