乌兰图嘎超大型锗矿床含锗煤的矿物学

内蒙古乌兰图嘎锗矿是我国近年来发现的产在煤层中的超大型锗矿床,锗金属储量达1600 t。以乌兰图嘎超大型锗矿床的含锗煤为研究对象,利用X射线衍射(XRD)、带能谱的扫描电镜(SEM-EDX)和电子探针(EPMA)详细研究了乌兰图嘎含锗煤及其同时代的红旗煤矿无矿煤的矿物学特征。分析结果表明,乌兰图嘎含锗煤中的主要矿物包括石英、蒙脱石;次要矿物包括长石、高岭石、伊利石;另含少量三水铝石、角闪石、叶蜡石、石膏、绿泥石、锐钛矿、黄铁矿、方解石、白云石和草酸钙石;微量的锆石、闪锌矿、白钨矿、重晶石、黄铜矿、卤化物、磷酸盐以及含Pb、Bi、Cr、As和Sb矿物。未发现含锗矿物。推测含锗煤中的锗可能主要呈有机结合,而Ba、Zn、Ti、W、Pb、Bi、Cr、Fe、As、Zr、Sb、Cu和REE可能主要与矿物相结合。此外,首次在乌兰图嘎含锗煤及红旗煤矿无矿煤中发现含银颗粒或自然银,推测胜利煤田的褐煤可能有相当规模的Ag矿化。

MINERALOGY OF Ge-BEARING COAL FROM WULANTUGA SUPERLARGE GERMANIUM DEPOSIT, INNER MONGOLIA, CHINA

The Wulantuga germanium deposit(WGD),with germanium(Ge) resources up to 1600 tons,is a super-large Ge deposit hosted in coal seams,which has been found in recent years.The mineralogical characteristics of Ge-bearing lignite from WGD,as well as the contemporary Ge-barren lignite from the Hongqi Coal Mine,were systematically studied by X-ray diffraction,scanning electron microscope with energy-dispersive X-ray spectrometer(SEM-EDX) and electron probe microanalyser(EPMA).Results showed that the primary minerals in the Ge-bearing lignite of WGD include quartz and montmorillonite,the secondary minerals include feldspar,kaolinite and illite,and minor gibbsite,hornblende,pyrophyllite,gypsum,chlorite,anatase,pyrite,calcite,dolomite and weddellite.SEM-EDX and EPMA analyses showed trace zircon,sphalerite,scheelite,chalcopyrite,halogenide,phosphate and Pb,Bi,Cr,As and Sb-bearing minerals exist in the Ge-bearing lignite of WGD.No Ge-bearing mineral has been detected.These results showed that Ge in Ge-bearing coal may be mainly associated with organic matter,while Ba,Zn,Ti,W,Pb,Bi,Cr,Fe,As,Zr,Sb,Cu,and REE may be mainly associated with mineral phases.Furthermore,silver-bearing particles or native Ag have been detected for the first time in Ge-bearing lignite from WGD,as well as in Ge-barren lignite from the Hongqi Coal Mine,indicating lignites from the Shengli Coalfield may contain considerable Ag mineralization.