Restrictive Factors Of Lithium In Clay Minerals

Clay minerals are the main component minerals of seal stone.In order to enrich the research on the physical and chemical properties and element composition of clay minerals,we study the clay minerals in the sediments of Guozhacuo and Taruocuo lakes in Tibet and discuss the mineral and chemical compositions,and various factors affecting the content of lithium of clay minerals in different lakes.Lots of measurements are carried out,such as X-ray powder diffraction(XRD),scanning electron microscope(SEM),inductively coupled plasma optical emission spectrometry(ICP-OES),and inductively coupled plasma mass spectrometry(ICP-MS).XRD results show that the clay minerals in Guozhaco have 68.78%illite,15.17%of mixed-layer illite,0.18%montmorillonite,4.59%kaolinite and 11.27%chlorite.Illite is the main component of the sediments,its crystallinity index is about 0.34.It is speculated that the climate of the formation of clay minerals in Guozhacuo area is arid,weak weathering and irregular burial.The clay minerals in Taruocuo contain 52.1%illite,37.72%mixed-layer illite,10%kaolinite and chlorite,and the illite crystallinity index is about 0.39.It is deduced that the climate when Taruocuo clay minerals was formed is arid and cold,and the weathering effect is stronger than that of the Guozhacuo area,the burial effect of sediments is not obvious.The clay minerals in the sediments may migrate from the outside to the lake,and the minerals are affected by weathering during the transportation process.After comparing with the element content of Dry Salt Lake in Qaidam area,summarizing the mineralization,p H value and lithium element data of different lakes on the Qinghai-Tibet Plateau,the author believes that the change of lithium content in lake water is most obviously affected by the possible source of lake water in the lake and evaporation,and it has no obvious correlation with lake water p H and lake salinity.The replenishment of the lake water source contains high lithium content and strong evaporation,which makes the lake rich in lithium.Lithium has different correlations with different types of clay minerals and the elements in them.The absolute value of the correlation coefficient is more closed to 1,the better the degree of correlation is considered.In Guozhacuo,the correlation coefficient between the content of chlorite and lithium is about 0.63.In Taruocuo,the correlation coefficient between the content of chlorite and lithium is about 0.66.The above correlation is moderate.The change trends of Li and B content in the clay minerals of salt lakes and freshwater lakes are similar,indicating that Li and B in salt lakes are symbiotic element pairs,and the enrichment rules of B and Li are the same.In saltwater lakes,there may be a small amount of Li~+in the clay structure to replace K~+in the illite interlayer domain,and the high content of K restricts the enrichment of Li in the clay.In freshwater lakes,the correlation coefficient(0.46)between Mg and Li is greater than that in salt lakes(0.28)and salt lakes(0.06).In addition to the depth of 100 cm,Guozhacuo has a high degree of correlation between Mg and Li in other positions.It is speculated that isomorphic substitution occurs in the mineral structure.