青海五龙沟金矿中金的赋存状态研究

青海五龙沟金矿石贵金属矿物以自然金为主,金品位为2.43 g/t,伴生低品位银,属于微细粒—超微细粒浸染型含碳、砷的极难选冶金矿石。为给该矿石的开发利用提供依据,采用X荧光分析法、化学分析、矿相显微镜、X射线衍射分析及MLA矿物自动定量系统等手段对矿石的化学成分、结构构造、矿物组成及金的赋存状态进行研究。结果表明:(1)矿石有价元素为金、银,有害杂质砷、碳含量较高,含金矿物主要有自然金及方锑金矿、黑铋金矿、碲金银矿等;(2)金粒大多数呈显微、超显微分散状态包含于毒砂及斜方砷铁矿中,其次包含于绢云母、绿泥石和石英等脉石矿物中,少数与黄铁矿和磁黄铁矿连生或包裹,显微镜中可见金不多,粒度大多小于1μm;(3)金嵌布粒度以微细粒为主,98.45%金粒粒度小于0.04 mm;黄铁矿、毒砂和磁黄铁矿的嵌布粒度以中细粒为主,均处于浮选的适宜范围;(4)金的选矿回收与硫砷化物的回收密切相关,尤其是要重视毒砂的回收。研究结果可以为该金矿石的合理开发利用提供技术依据。

Research on Occurrence Status of Gold from Gold Mine in Wulonggou of Qinghai

The precious metal mineral of Wulonggou gold ore in Qinghai is mainly natural gold and the gold grade is 2.43 g/t.Associated silver grade is also relatively lower.It is microfine-superfine disseminated gold deposit，containing carbon and arsenic.It is difficult to mineral processing and smelting.X-ray fluorimetric analysis，chemical analysis，mineralogical microscope，X-ray diffraction analysis，MLA mineral automatic quantitative system was used to research mineral chemical contents，structure，mineral components and stockpile status of the ore.The result shows that:①Valuable elements is gold and silver，harmful substances carbon and arsenic contents is high.Gold containing minerals are include natural gold，aurostibite，maldonite and petziteetc.②Gold mainly in microscopy，super microscopy dispersed state included in arsenopyrite or loelling，some contained in gangue minerals of sericite，chlorite and quartz，small amount contained in pyrite and pyrrhotite，most particle size is less than 1 μm.③Mainly gold dissemination size is microfine，98.45% gold size was less than 0.04 mm，pyrite，toxic sand and pyrrhotite are of medium and fine，suitable for flotation.④Gold recovery has closed relationship with the sulfur arsenic recovery，arsenopyrite recycle should especially pay more attention to.The results provide technical basis for rational exploitation and utilization of the ore.