甘肃全鑫金矿物质组成及金的赋存状态

Contents of ores and host state of gold in Quanxing gold deposit in Gansu

全鑫金矿为变质碎屑岩型金矿,矿石的化学成分较简单,主要为SiO2(73.60%)和A l2O3(10.40%),有用元素主要为Au(平均3.45×10-6),其次为Ag,有害元素主要是C有机,As,S,含量很低。主要金属矿物为褐铁矿、赤铁矿及黄钾铁钒;脉石矿物以石英、长石、绢云母及粘土矿物为主。矿石为自形-半自形粒状结构、浸染状构造。矿石中金大多为自然金,粒度一般<0.005 mm,主要以微细粒包裹金的形式存在,部分为裂隙金,金的载体矿物主要为褐铁矿、黄铁矿。

The Quanxing gold deposit is a meta-clastic rock type deposit, chemical compositions of the ores are relatively simple, mainly consisting of SiO2（ -73.60% ）, Al2O3 （ -10.40% ）. The useful elements of the ores mainly contain gold （averaging 3.45×10^-6）, and silver, and the harmful elements are lower contents of organic carbon, arsenic and sulphur. The main metal minerals include limonite, hematite and jarosite, and the gangue minerals are dominated by quartz, feldspar, sericite and clay minerals. The ores show idiomorphic or hypidiomorphic granular structure and disseminated texture. Gold in ores usually exists as natural gold witb the grain size less than 0.005mm, mainly trapped within gold-host minerals（ dominated by limonite and pyrite） and partly distributed in their cracks.