15 - Flotation of Copper-Lead-Zinc Ores

Abstract

The copper–lead–zinc ores have an origin similar to copper–zinc and lead–zinc ores, the exception being those ores that contain copper, lead and zinc as the principal economic minerals. In addition, some of these ores contain significant amounts of precious metals and, more rarely, cobalt and nickel. The treatment processes for the beneficiation of copper–lead–zinc ores are the most complex of all ores processed. The flotation behavior of the individual minerals is different from that of either lead–zinc or copper–zinc ore and therefore the treatment process is tailored based on the processing characteristics of the individual ore types. The sequential copper–lead–zinc flotation practice utilizes several major reagent combinations in sequential copper–lead flotation, which include: bisulfide method, starch/lime method and soda ash/SO2 or lime/SO2 method. The bulk copper–lead flotation with depression of zinc followed by copper–lead separation and re-flotation of zinc is the most common practice in the treatment of copper–lead–zinc ores. About 90% of operating plants use this method. The bulk concentrate is usually contaminated with pyrite and zinc. Therefore, upgrading of the lead concentrate after copper–lead flotation is usually required.