云南官房铜矿床矿石矿物特征及银的赋存状态

通过显微镜鉴定、电子探针(EPMA)及扫描电镜能谱分析(SEM/EDS)等方法,首次对官房铜矿的矿物组合和银的赋存状态进行了研究。初步查明,矿石矿物为中-低温热液成因,并受火山机构及断裂构造的控制;银矿物主要为碲银矿和辉银矿。矿石中银与铜呈明显正相关关系,而方铅矿中不含银。银主要以类质同象的形式赋存于含铜矿物或黄铁矿中;银的独立矿物含量低,且多呈包裹体的形式存在于黄铜矿、斑铜矿及黄铁矿中,或以微细粒状赋存于矿物颗粒间和斑铜矿的表面。

Characteristics of ore minerals and modes of occurrence of silver in Guanfang copper deposit, Yunnan Province

Based on mineral observation by means of microscope,EPMA and SEM/EDS,the authors studied modes of occurrence of silver and mineral associations in the Guanfang copper deposit of Yunnan Province. The deposit is controlled by structures. Ores are characterized by mesothermal-epithermal mineral constituents. Two kinds of silver minerals,namely hessite and argentite,have been found. Silver is positively correlated with copper in ores and is absent in galena. Silver occurs predominantly in the form of isomorphism in cupreous minerals and pyrite. Silver rarely occurs as independent argentiferous minerals,and is mainly existent as inclusions in chalcopyrite,bornite and pyrite. It is also present in fissures and intergranular space of minerals or at the surface of bornite.