Research On The Occurrence State Of Gold In Carlin-type Gold Deposits

The Yunnan Funing Zhesang deposit and the Guizhou Zhengfeng Shuiyindong gold deposit are typical Carlin-type gold deposits in the "Golden Triangle,region of southwest China's Yunnan,Guizhou and Guangxi Province.The pyrite and arsenopyrite are the main gold-bearing minerals in the deposit.Research on the occurrence of gold in the Carlin-type gold deposit is of great significance for the selection,smelting,development and utilization of this type of deposit.However,previous studies on the occurrence of Carlin-type gold deposits have not been through enough and have been controversial.Therefore,The object of this study is the gold-bearing iron ore and arsenopyrite of different types of gold ore(diabase type ore,argillaceous slate or siltstone ore,marl type ore)in the Zhesang Gold Deposit,and conduct the analysis to mineral and geochemical characteristics.this study applied scanning electron microscopy and electron microscopic microscopy to observe the mineralogical observation and composition of the main gold-bearing mineral pyrite and arsenopyrite in the Shuiyindong gold deposit in Guizhou.The results showed that:(1)Whether it is the Shuiyindong gold deposit or the Zhesang deposit,the Au and As contents in different types of pyrite and arsenopyrite have a dense positive correlation.(2)The occurrence of the Shuiyindong gold deposit and the Zhesang gold deposit is mainly caused by ultra-microscopic Au+in the pyrite and arsenotic lattice structure and on the pyrite surface by the "invisible" micro AuO;It is pointed out that a small amount of "visible" natural gold was found at the Shuiyindong gold deposit.The visible micron-scale natural gold AuO is adsorbed on the surface of pyrite and near the carbonate rock vein,and the particle size ranges from 0.5 ?m to 200 ?m.(3)The study found that among the diabase-type ores,the tip of broken?fine-grained self-shaped?elongated rhombic arsenopyrite have superior gold-bearing properties;in argillaceous slate or siltstone-type ores,vein-like pyrites Aggregates and coarse-grained self-shaped pentagonal dodecahedrons are more gold-bearing;marl stone-type ores generally contain gold,and fine-grained rhombic arsenopyrites have the best gold-bearing properties.The gold content of gold-bearing minerals in different ore types is closely related to silicification?carbonization?sericitization and carbonation.