察尔汗盐湖别勒滩区段固态锂的赋存状态与分布特征

Occurrence state and distribution characteristics of solid lithium in Bieletan section of Qarhan Salt Lake

察尔汗盐湖别勒滩区段赋存大量具有开发潜力的固态锂资源,但目前对固态锂的赋存状态和分布特征研究较少。文章利用水溶法、稀酸溶法和全岩溶解法3种方法对该区4个钻孔的15件岩芯样品进行主微量元素分析。研究结果显示,水溶法的w(Li)(Li溶出量,余同)为23.37×10-6~85.98×10-6,稀酸溶法的w(Li)为47.77×10-6~139.58×10-6,全岩溶解法w(Li)为49.47×10-6~151.64×10-6。以同一样品全岩溶解所得的w(Li)为100%,水溶法、稀酸溶法的w(Li)平均值分别为56.44%和92.83%。结合矿物薄片鉴定、扫描电镜分析和X射线衍射的鉴定结果,岩芯样品中的矿物主要是石盐、杂卤石、光卤石、石英、绿泥石、钠长石、硬石膏、白云石、伊利石、菱镁矿和方解石等,推测固态锂大部分赋存于易溶盐类矿物,其余赋存于不易溶的碳酸盐、硫酸盐和硅酸盐等矿物中。根据4个钻孔岩芯样品的Li溶出量来看,察尔汗盐湖别勒滩区段固体钾盐层中固态锂的分布特征是由西向东逐渐递减,与别勒滩区段卤水Li含量在空间上的规律性相同,说明别勒滩区段固态锂的含量可能受到卤水中Li浓度的影响。

The Bieletan section of Qarhan Salt Lake hosts abundant solid lithium resources with high potential for ex‐ploitation.However the studies with respect to the distribution and characteristics of those solid lithium resources are very scanty.This study analyzed the major and trace elements of 15 samples from 4 boreholes dissolved by distilled water,dilute acid,and strong acid,respectively.The results show that the samples dissolved by above sol‐vents generate solutions with Li concentrations ranging from 23.37×10-6~85.98×10-6,47.77×10-6~139.58×10-6and 49.47×10-6~151.64×10-6,respectively.We postulate the leaching amount of Li by strong acid was thorough(100%),then the average leaching efficiencies by distilled water and dilute acid are 56.44%and 92.83%,respec‐tively.Those samples are composed of halite,polyhalite,carnallite,quartz,chlorite,albite,anhydrite,dolomite,il‐lite,magnesite,calcite,etc.,based on thin section observation,XRD and SEM analyses.Thus it is suggested that most Li resources are present in soluble salt minerals,and the rest Li resources occur within silicates,sulfate and carbonates.In the light of leaching amount of Li from 4 boreholes,the contents of solid Li within Bieletan section of the Qarhan Salt Lake show a decreasing trend from west to east,which is consistent with the distribution pattern of Li concentrations of brines,thus suggesting the contents of solid Li is influenced by Li concentrations of brines.