松辽盆地西南部DL铀矿带铀赋存状态及矿物组成特征

The Occurrence and Mineral Composition of Uranium Ore of DL Mineralized Zone in Southwestern Songliao Basin

DL铀矿带是松辽盆地近年找矿的新发现。文章利用扫描电镜、电子探针和自动矿物参数定量分析系统等测试手段对该区矿石样品进行了铀赋存状态研究,结果表明:研究区铀主要以沥青铀矿、含锆铀矿物、含钛铀矿物等独立铀矿物以及黏土吸附、有机质吸附、锐钛矿吸附等吸附铀形式存在,铀矿物呈微粒状、细脉状、块状和团块状产出,空间上与磷灰石、硒铅矿、黄铁矿、有机质和碳酸盐等关系密切,与周边铀矿床的铀存在形式略有差别,其中含锆铀矿物在砂岩型铀矿中属首次发现。矿物组成以石英、长石、黏土矿物和碳酸盐为主,此外还有一定量的钛铁氧化物、重晶石、铁氧化物和少量独居石、磷钇矿、硒铅矿等副矿物。利用电子探针的铀定量分析数据和自动矿物参数定量分析系统的铀矿物定量分析数据,首次定量计算了不同存在形式铀的分布率,结果显示:独立铀矿物中沥青铀矿和含锆铀矿物的分布率最高,吸附铀以黏土矿物吸附占优势,有机质和锐钛矿吸附次之。铀赋存状态及矿物组成的精细厘定对矿床成因与选冶工艺研究等具有重要意义。

DL uranium mineralized zone is the new prospecting discovery in Songliao basin in recent years.In this paper,the uranium occurrence of ore samples was studied by means of scanning electron microscope,electron probe microanalyzer and automatic mineral parameter quantitative identification system.The results showed that the uranium in the study area mainly exists in the form of independent uranium minerals such as pitchblende,and Zr-rich uranium minerals,Ti-rich uranium minerals,as well as clay adsorption,organic matter adsorption,anatase adsorption and so on.The uranium minerals occur in particulate,veinlet,block and mass form and are symbiotic with apatite,clausthalite,pyrite,organic matter and carbonate in space,and it is slightly different from the surrounding uranium deposits,of which,the Zr-rich uranium minerals were discovered for the first time in sandstone-type uranium deposits,which is mainly composed of quartz,feldspar,clay minerals and carbonate.In addition,there is a certain amount of ilmenite,barite,hematite and a small amount of monazite,xenotime,clausthalite and other accessory minerals.The distribution rates of uranium in different existing forms were quantitatively calculated for the first time by using quantitative analysis data of uranium minerals from electron probe micro analyzer and quantitative analysis data of minerals from automatic mineral parameter quantitative identification system.The results showed that the distribution rates of pitchblende and zircon-bearing uranium minerals in independent uranium deposits are the highest,and the clay minerals adsorption dominates the adsorption of uranium,followed by organic matter and rutile adsorption.The fine determination of the uranium occurrence state and mineral composition is of great significance to the study of ore genesis and the benefication-leaching process.