陕西略阳铧厂沟金矿床金的赋存状态研究

陕西略阳县铧厂沟金矿床为一正在开采的小型金矿床。利用野外观察、显微镜观察、电子探针扫描等综合分析技术对金矿石中金的赋存状态进行了研究。结果表明,金主要以独立矿物相存在,金的载体矿物主要为黄铁矿,其次为石英、白云石、黄铜矿、砷黝铜矿。金矿物均为自然金(成色为945～982),未发现含银自然金及银金矿等矿物。金的嵌布类型有包裹金、裂隙金、粒间金和连生金4种。矿石中自然金的粒度主要以显微微粒金(0.010～0.005 mm)为主(约占44%),其次是显微细粒金(0.020～0.010 mm)(约占22%)和显微极微粒金(0.005～0.001 mm)(约占19%)。显微中粒金—巨粒金数量较少(约占14%),但其面积含量较高(约占57%),对于矿石品位和储量来说非常重要。还讨论了铧厂沟金矿床自然金嵌布特征的地质意义以及金成色较高的成因。

Study of Occurrence of Native Gold in the Huachanggou Gold Deposit, Shaanxi Province, China

Located in the southern Qinling Mountains,the Huachanggou gold deposit is a small gold deposit which is currently being mined.On the basis of detailed field geological survey and systematic laboratory study including microscope observation,electron probe scanning,X-ray surface scanning,the occurrence of gold has been identified.The result shows that the gold exists mainly as independent mineral phase;the carriers are pyrite,quartz,dolomite,chalcopyrite and tennantite.The gold minerals are native gold with the fineness of 945 to 982.Neither argentiferous native golds nor electrums are found.Gold is embodied as inclusion,fissure-filling,intergranular and interlocking form.The gold granularity is mainly characterized by micro particulate(0.010-0.005 mm,which accounts for 44%),micro fine particulate(0.02-0.01 mm,which accounts for 22%) and extra micro particulate(0.005-0.001 mm,which accounts for 19%).The micro medium-to-giant grained golds are less in number,however,they are significant to ore grade and total resource.The authors also discussed the causes and significance of the high fineness and the distribution of granularity of the native gold.