安徽沙溪斑岩铜矿床中伴生金的赋存状态

矿体赋存于燕山早期形成的石英闪长斑岩及闪长玢岩中。矿石的主要金属矿物有:黄铜矿、黄铁矿、斑铜矿、自然金、银金矿等。黄铁矿、黄铜矿是金的主要载体矿物。通过矿相鉴定、单矿物化学研究、物相分析,电子探针分析、透射电镜分析等,查明了金的赋存状态。显微金呈包体状态包含于黄铜矿之中,粒径为5—20微米。次显微佥呈球状、链状及不规则状分布于黄铁矿晶体边缘及微裂隙中。经探针分析,金的成色为790—850,平均成色为815。经物相分析,金的矿物量为85%—95%,表明金是以矿物态存在。我国玉龙、德兴、多宝山等地的斑岩铜矿都有不同程度金的显示,查明金的富集规律及赋存状态,对于综合开发斑岩铜矿,提高矿床利用价值将会开拓新的前景。

The Mode of Occurrence of Associated Gold in the Shaxi Porphyry Copper Deposit, Anhui

The orebodies occur in quartz diorite-porphyry and diorite-porphyrite; whichwere formed in the early Yanshaniaw orogenic phase and are both: parent !rocksand host rocks of the orebodies. The main metallic minerals are chalcopyrite,pyrite, bornite, native gild and, eiectrum: The main ..gold-containing minerals arepyrite and chalcopyrite. The mode of occurrence of gold in minerals has-been studied by means ofore microscopy, mineral chemistry, phase analysis and electron microprobe andtransmission-electron microscope. It is found that micro-goad occurs in chalcopy-rite as inclusions with diairieters of 5-20µ, while submicrogold appears as sphe-rules, chains,. or. in irregular shapes, occurring on the crystal faces or in themicrocracks of pyrite. According. to electron probe analysis, the fineness of goldis 790-850 with an average value of 815. Phase analysis showed that the contentof gold reach ed 85一95 percent, which indicates that gold occurs as minerals.In China, there is more or‘ less gold'' in the porphyry copper ores indistricts as Yulong, Dexing, Duobaoshan etc. To find out the enrichment zone such and horizon of gold and its mod-of occurrence will have important significance todevelopment comprehensively the porphyry copper deposits so as to raise theircommercial value.