Technological difficulty: (1) Lead flotation need to put a large number of lime, the subsequent selection of zinc need to add a lot of Ammonium Bicarbonate to adjust the pH value, which cause high ammonia content, working environment bad; (2) High alkali environment lead to zinc oxide flotation bubble rich and large viscosity, high pH backwater, need to be treated before reuse;(3) The original desliming flotation process resulted in nearly 50% loss of zinc metal and low recovery of zinc oxide.

Result: (1) Low alkali and desliming process adopted. During lead flotation process, use combination of collector which has better effect for lead selection, improve the efficiency of lead flotation; (2) develop and use one kind of zinc oxide flotation miscible collector, zinc oxide mineral flotation recovery significantly improved. (3) When the original ore containing zinc 7%, lead 0.7%, the final zinc sulfate concentrate containing 54% lead, lead 1.2%, zinc recovery rate of 70%, zinc oxide concentrate 35% zinc, lead 4.3%, zinc recovery rate of 14%, total zinc concentrate 50%, the total recovery rate 84%, to achieve the efficient comprehensive recovery of hard selection lead-zinc mine; (4) Industrial test to improve lead recovery rate of 4%, reduce the cost of flotation agent RMB 6 yuan/ton.