Scanning electron microscopy analysis of arsenopyrite monomineral in Dapingshan Copper Deposit

Dapingshan Copper Deposit is located in the west of Hengxi Town in Jiangning District,Nanjing. Based on geochemical and geophysical prospecting anomalies,it was found in early 1970. The primary useful constituent in the mineral ore was Cu,accompa- nied by other elements such as As,Zn,Ag,Au,Co and Ni etc. Among them,the content of As was higher,that could reach 0. 2% to 0. 9% partly. The detection of arsenic,under the microscope,appeared chiefly as the form of sulphide in Dapingshan Copper De- posit through scanning electron microscope analysis,with the appearance of arsenopyrite independently distributed in the ore. Arseno- pyrites are mainly found in the form of automorphic-hypidiomorphic granular texture and xenomorphic granular texture. There were two occurrence modes: one was independent sparsity disseminated mineral with partial strip and medium dense dissemination distributed in the ore,and the other was an alterated generation of paragenetic chalcopyrite and pyrite in the ore,which were formed earlier.