四川甲基卡X03号脉接触变质岩中Cs等稀有元素赋存状态及其综合利用建议

【研究目的】甲基卡稀有金属矿区是中国规模最大的花岗伟晶岩型稀有金属矿床富集区，X03号脉是近年来该矿区发现的以锂为主的超大型稀有金属矿床，在其围岩中发育电气石、堇青石化接触变质带，形成的蚀变岩具有Li、Rb、Cs等稀有金属矿化。Cs是重要的稀有金属元素之一，寻找更多可利用的铯资源成为当务之急。【研究方法】对钻孔岩芯中电气石角岩、堇青石化片岩等接触变质岩样品进行了稀有元素含量分析，并采用LA-ICP-MS对电气石、堇青石、黑云母、白云母等变质矿物进行了单矿物微区分析。【研究结果】接触变质岩中Li、Rb、Cs具有较高的含量，其平均值分别为0.296%、0.067%、0.052%，均达到综合利用的边界品位或最低工业品位，其特征与蚀变岩型铯云母岩矿床极其相似。Cs元素主要以类质同象的形式赋存于黑云母之中，是引起接触变质岩石Cs元素富集的主要原因。【结论】在X03号脉的进一步勘查中，应对接触变质岩石中稀有金属资源，特别是Cs资源进行评价，并对其进行综合利用。创新点：分析了X03号脉接触变质岩中Cs等稀有元素的含量，指出了Cs元素主要以类质同象的形式赋存于黑云母之中，应对其进行综合利用。

Distribution and occurrence of Cs and other rare elements in contact metamorphic rocks of X03 supergiant deposit in Jiajika, Sichuan and its comprehensive utilization suggestion

This paper is the result of mineral exploration engineering.Objective] The Jiajika rare metal mining area is the largest granite pegmatite-type rare metal deposit in China. The recently discovered Vein X03 is an supergiant rare metal deposit dominated by lithium. The tourmaline and cordierite contact metamorphic zones have been developed in the surrounding rocks of Vein X03, and mineralization of rare metals such as Li, Rb, and Cs occurs in the altered rocks. Cs is one of the important rare metal elements, and it is imperative to find more available cesium resources.Methods] In this research, the content of rare elements in the contact metamorphic rock samples in drilled cores, such as tourmaline cornerstone and cordierite schist, was analyzed. The monomineral microanalysis of tourmaline, cordierite, biotite and white mica was conducted using LA-ICP-MS.Results] High contents of Li, Rb, and Cs in the contact metamorphic rocks were observed, and the average values were 0.296%, 0.067%, and 0.052%, respectively. The contents of these elements reach the boundary grade or the lowest industrial grade for comprehensive utilization, and its characteristics are very similar to those of altered rock cesium mica deposits. Cs element mainly occurs in biotite in the form of isomorphism, which is the main reason for the enrichment of Cs in the contact metamorphic rocks.Conclusions] In the further exploration of Vein X03, the rare metal resources, especially Cs resources, in the contact metamorphic rocks should be evaluated and comprehensively utilized.Highlights: The contents of rare elements, such as Cs, in the contact metamorphic rocks of Vein X03 was analyzed. Cs element mainly occurs in biotite in the form of isomorphism, which should be comprehensively utilized.