大平山铜矿毒砂单矿物扫描电镜分析

Scanning electron microscopy analysis of arsenopyrite monomineral in Dapingshan Copper Deposit

大平山铜矿床位于南京市江宁区横溪镇西侧,矿石中有用组分除铜以外,还伴生有As、Zn、Ag、Au、Co和Ni等元素,其中As元素质量分数较高,局部达0.2%～0.9%。通过显微观察和扫描电镜能谱分析,发现大平山铜矿矿石中As元素主要以硫化物形式,呈毒砂独立矿物以自形—半自形粒状、他形粒状赋存于矿石中。赋存方式主要为:以独立矿物呈稀疏浸染状分布于矿石中,局部呈条带状和中等稠密浸染状分布于矿石中;以交代方式与黄铁矿和黄铜矿共生于矿石中,但毒砂形成晚于黄铁矿和黄铜矿。

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, accompanied 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, undel ＇the microscope, appeared chiefly as the form of sulphide in Dapingshan Copper Deposit 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 aherated generation of paragenetic chalcopyrite and pyrite in the ore, which were formed earlier.