Study on comprehensive recovery of metals in Ge-rich complex lead-zinc sulphide and mixed ores

From Yunnan, China, the ore falls into polymetallic ore containing Pb, Zn, S, Fe, Ag, Ge, Cd, and Ga. With the abundant valuable metals the ore possesses high value of utilization. Mineralogical investigation shows that the deposit is a quite complex one in terms of its ore type and its oxidation rate, and accordingly can be divided into sulphide ore, mixed one and oxidized ore according to the oxidation rate. Comprehensive process mineralogy study indicates that occurring in fine dissemination with uneven size distribution the valuable minerals closely associated with each other, indicating that the recovery of the metals through flotation is a difficult work. Considering the fact that the oxidation rate of lead and zinc minerals vary in a relative large range and also the fact that the ore contains many of valuable minerals. The authors of BGRIMM adopted the principle technique process to treat the complex ore, in which sulphides are always taken as priority to be floated over oxidized minerals both in the case for lead and zinc flotation, and this is followed by the flotation of oxidized minerals. Besides, the idea of electro-chemical control flotation was introduced in the development of flotation technique to meet the varied ore natures. By employment of iso-flotability- differential bulk flotation followed by separation in low level alkaline the flotation of oxidized zinc minerals at normal temperature without desliming could be achieved. The use of selective collectors both for lead sulphides and zinc sulphides and the use of a kind of powerful selective collector for zinc oxides successfully make the impurity metals reporting to the concentrates in a moderate level. With the accompanying valuable elements well recovered in respective high quality concentrates the respective overall recovery averaged 89.73% for Pb, 95.23% for Zn, 95.77% for Ge, 94.20% for Ag, and 87.26% for Cd.