摘要
应用偏光显微镜与电子探针相结合的手段是研究载金矿物的主要方法。本文采用镜下鉴定和电子探针分析技术,对赵家庄金矿中载金矿物含量、形态特征及其与其他矿物的空间关系开展研究,并对载金矿物进行定性和定量分析,探寻具有找矿意义的载金矿物和总结标志矿物特征。结果表明:研究区金矿石中主要载金矿物为黄铁矿,少量为黄铜矿、闪锌矿,这些载金矿物中Au含量依次为:细晶黄铁矿>粗晶黄铁矿>草莓状黄铁矿>黄铜矿。不同时期的黄铁矿(粗晶黄铁矿、细晶黄铁矿、草莓状黄铁矿)中Au的分布均匀,但存在差异性,主要表现为细晶黄铁矿和草莓状黄铁矿中的Au含量较高(平均含量0. 14%～0. 18%),这种现象表明此类矿物为构造热液期形成,金易富集。Au以两种形式存在,一种是"可见金"包裹于脉石矿物中,或以裂隙金的形式嵌布在矿物晶隙及裂隙中;另一种是"不可见金"以纳米级颗粒金的形式存在于载金矿物中,也是Au的主要存在形式。本研究为后期矿床的成因、成矿过程和成矿机理研究提供了佐证,同时易于根据含金矿物的特征选择合适的选冶方法。
BACKGROUND:Microscopy and Electron Microprobe are the main methods for the study of gold-bearing minerals.Using these methods,the content and morphology of gold-bearing minerals and their spatial relationship with other minerals were studied in the Zhaojiazhuang gold deposit.The gold-bearing minerals were qualitatively and quantitatively analyzed.OBJECTIVES:To summarize the gold-bearing minerals with the significance of prospecting and the features of indicator minerals.METHODS:Microscopy and Electron Microprobe.RESULTS:The main gold-bearing mineral is pyrite,then chalcopyrite and sphalerite.The contents of Au in the main gold-bearing minerals follow the sequence of fine-grained pyrite>coarse-grained pyrite>strawberry pyrite>chalcopyrite.The distribution of Au in different stages of pyrite(coarse pyrite,fine pyrite,strawberry pyrite)is uniform.Fine-grained and strawberry pyrite have higher gold content(average 0.14%-0.18%),indicating that these types of pyrite formed by tectonic hydrothermal fluids where Au concentrates more easily.There are two occurrences of gold in the Zhaojiazhuang Au deposit.Visible gold is wrapped in gangue minerals,or embedded in mineral crystal gaps and cracks in the form of fissure gold.Invisible gold exists in the gold-bearing minerals in the form of nano-scale gold particles.Invisible gold is the main existence form of Au.CONCLUSIONS:This study provides evidence for the study of the genesis,metallogenic process and mechanism of the same deposits and it is easy to select suitable methods for ore selection and smelting based on the characteristics of gold-bearing minerals.
作者
荆国强
廉康
胡菲菲
李磊
杜亚龙
JING Guo-qiang;LIAN Kang;HU Fei-fei;LI Lei;DU Ya-long(No.203 Research Institute of Nuclear Industry,Xianyang 712000,China)
出处
《岩矿测试》
CAS
CSCD
北大核心
2018年第5期490-498,共9页
Rock and Mineral Analysis
基金
中国核工业地质局铀多金属矿普查项目(201564)
关键词
电子探针
金
赋存状态
载金矿物
黄铁矿
Electron Microprobe
gold
occurrence state
gold-bearing minerals
pyrite
