Technological Mineralogy Research of Silver in the Lead-Zinc Ore Deposit in West Baoshan, Hunan Province

The Lead-Zinc ore deposit in west Baoshan, Hunan Province, belongs to a medium-low temperature hydrothermal filling-metasomatic deposit, of which the grade of silver is 156.6 μg/g through chemical analysis. The study of the process mineralogy of silver in this ore zone is presented in this paper. By means of ore microscopy, chemical analysis, Scanning Electron Microscope (SEM) and Electron Microprobe Analysis (EPMA), the main types of silver, host occurrence of Ag and technological features were studied. Silver is mainly enriched in the upper seam rather than the lower seam, and is richer in the NW-SW seam than that in the NE-SE seam, based on the chemical analysis of ore samples, of which the ore types mainly include dolomite-type, sandstone-type, limestone-type and breccias-type, with silver content of 595.78 μg/g, 247.97 μg/g, 195.8 μg/g and 169.73 μg/g, respectively. The highest content of silver was found in dolomite-type ores and the lowest in breccias-type. By means of ore microscopy, Scanning Electron Microscope (SEM) and Electron Microprobe Analysis (EPMA), the metal minerals are mainly galena, sphalerite, chalcopyrite and pyrite, and freibergite, tennantite and and galena were the main silver-bearing minerals.The silver has two main forms in the deposit. The first form is independent silver-bearing mineral, freibergite. Quantitative analysis of EPMA showed that the content of silver in freibergite were 10.179%-13.579% with average content of 12.061%. The second form occurs in galena, the content of silver were 0.011%-0.127% with average content of 0.069%. By means of phase analysis, individual minerals analysis, it identifies that 84.78% of silver in ore mainly hosted in galenite, galenite is main carrier mineral. Partition calculation indicates that the convergence of silver and lead. This study suggests that, in order to improve silver recovery from ores during dressing processes, particularly care and attention should be paid to the recoveries of lead and zinc at the fine-grain level.