Mineralogy and Innovative Flash Flotation Separation of Cu-Pb-Zn Polymetallic Ore in Weak Acidic Pulp

Abstract

Intimate knowledge of the mineralogical assembly of the Yushui complex ore rich in Cu, Pb, and Ag is essential if efficient separation processing is to be conducted. With the aid of testing instruments, such as scanning electron microscope (SEM), X-ray diffractometer (XRD), and mineral liberation analyzer (MLA) combined with energy-dispersive X-ray analysis (EDX), the texture, such as the size distribution, dissemination, and association of the minerals, was investigated. The results demonstrate that the ore consists of 35 categories of minerals, assaying Cu 7.99%, Pb 9.39%, and Zn 1.96% in the forms of chalcopyrite, galena, and sphalerite, respectively, and silver assaying 157.9 g/t is closely associated with these sulfides; sulfides are present in amounts of 80.31% of the total, traditional gangues only 19.69%, and pyrite as a Cu-Pb-Zn-Ag carrier mineral up to 44.80%. According to the characteristics of the ore, the innovative process of flash copper flotation in weak acidic pulp and lead flotation, followed by further copper recovery, was developed. The closed-circuit test shows that copper concentrate assays Cu 16.33%, Pb 7.98%, Ag 242 g/t at Cu recovery of 86.67%; lead concentrate contains Pb 46.23%, Cu 3.75%, Ag 165 g/t at Pb recovery of 56.84%; total recovery of silver in both concentrates is 75.57%.