焦家金矿主矿区金矿石的赋存特征

The Occurrence Characteristics of Gold in the Jiaojia Gold Deposit

焦家金矿带是莱州-招远金矿区最重要的金矿带之一,产状复杂且性状变化较大。以往研究主要针对矿物种类、载金矿物及其形状及嵌布关系等进行分析,缺乏对金粒矿物学、金矿物种类及金颗粒的成色研究。本文采用偏光/反光显微镜、体视显微镜、扫描电镜、能谱仪、X射线衍射仪等技术手段对焦家金矿主矿区深部开采的矿石样品进行分析,研究内容主要包括金赋存状态、金粒度、金形状、金矿物类型及不同大小金粒的成色特征。结果表明:载金矿物主要以黄铁矿、黄铜矿等硫化矿和石英、长石等脉石矿物为主。金赋存状态有裂隙金(64.82%)、包裹金(19.29%)、晶隙金(15.89%);黄铁矿、黄铜矿中金粒较大,连群分布占多数,脉石中金粒细小,孤立分布占多数。金矿物形状复杂,主要有球状金、三角形金、矩形金。金矿物种类丰富,以自然金、银金矿、自然银、含铁自然银为主,其次为金铜矿、螺硫银矿、碲化金银。金矿物粒度范围较大,大金颗粒可达到90～110μm,小金颗粒只有2～3μm。金银矿物的成色普遍较高,大粒金成色低,以银金矿为主,小粒金成色高,大都为自然金。本文丰富了焦家金矿矿物学研究的内容,为后续选冶工艺提供了调控依据和重要信息。

The Jiaojia Gold Mine is one of the most important gold deposits in the Laizhou-Zhaoyuan gold mine,in which gold occurrence is complex.Previous research has focused on mineral types and shapes,gold-bearing ore species and relationship between minerals.However,studies of detailed gold mineralogy,occurrence characteristics,and fineness of different gold grain have been largely overlooked.The samples collected from the Jiaojia Gold Mine were comprehensively studied using Advanced Polarized Light Reflective Dual Microscope,Stereoscopic Microscope,Scanning Electron Microscopy,Energy Spectrometer and X-ray Diffractometer.The results show as following：main gold bearing minerals are sulfide and gangue,sulfide was mainly pyrite and chalcopyrite,gangue was mainly quartz and feldspar.The occurrence types of gold included 64.82％ of intercrystalline gold,19.29％ of inclusion gold and 15.89％ of fissure gold.Gold size was larger in pyrite and chalcopyrite than in gangue minerals.Meanwhile,the majority of gold was distributed as groups in sulfide minerals and isolation in gangue minerals.The gold shapes were mainly spherical,triangular and rectangular.Gold species were abundant,such as natural gold,electrum,and natural silver and natural silver including iron,and less as auricupride,acanthite,gold and silver telluride.The sizes of gold have a wide range,as large grains are up to 90 -110 μm and small grains are 2-3 μm.The fineness of large gold particles was low and the main ingredient was electrum,whose main ingredient was natural gold in small particles.