甘肃新金厂金矿床矿石特征

Ore character of Xinjinchang gold deposit, Gansu

新金厂金矿为中型高氧化蚀变岩型金矿床,矿体严格受断裂裂隙控制,多赋存于辉绿岩中。化学分析结果表明,矿石的有用组分单一,有害杂质少,金矿物主要为含银自然金。主要的金属矿物为黄铁矿、褐铁矿,同时也是主要的载金矿物;非金属矿物主要为石英、长石、绿泥石。矿石多具自形、半自形、他形粒状结构,以脉状、角砾状构造为主。人工重砂样品分析共获得147粒自然金,形态为蜂窝、树枝、不规则粒状等,赋存状态以裂隙金为主,其次为粒间金,包裹体金仅占10%,自然金为显微金。主要类型为石英细脉 碎裂蚀变岩型,破碎带中褐铁矿化、黄铁矿化、硅化强烈,次生氧化作用较强。

The Xinjinchang gold deposit is a middle scale altered rock-type gold deposit with high oxidation.The ore body is controlled by the fault fissure strictly and occurred in the diabase.The chemical analysis show that the useful composition in the ore is simple,harmful composition is lack and the major gold mineral is silver-bearing nature gold. The major metallic minerals and also the major gold carrier minerals are pyrite and limonite; the nonmetallic minerals are quartz, feldspar and chlorite. The automorphic, hypidiomorphic and xenomorphic granular textures are the main ore textures and vein and brecciated structures are the main ore structure. 147 pills nature gold are obtained by artifical panning and its forms are honeycomb,dendritic and irregular granular et al.Gold occurs mainly in shape of fissure gold,the secondly is interparticle gold, and inclusion gold takes only about 10%. The nature gold is in microsize.The major type is quartz vein-cataclassic altered rock-type, the limonization, pyritization and silication are strongly in the fracture zone, and the secondary oxidation is less stronger.