Hydrochemical Characteristics and Sources of Lithium in Carbonate-Type Salt Lake in Tibet

With the development of green energy, the demand for lithium resources has increased sharply, and salt lakes are an important source of lithium. In China, the Qinghai–Tibet Plateau has substantial lithium resources, and the Bangor Co Salt Lake is a typical Li-rich carbonate salt lake in northern Tibet. Research into the lithium source of the lake is of great significance for future sustainable industrial development. This article selects the Bangor Co Salt Lake recharge water system (river and cold spring water) and brine samples as the research objects, conducts hydrochemical composition and isotope testing of the water body, and determines the anions, cations, and B isotopes of the samples. This article uses the Piper three-line diagram, Gibbs diagram, and ion ratio relationship to study the hydrochemical characteristics and major ion sources of recharge water systems and salt lakes. The results indicate that the hydrochemical type has transitioned from the strong carbonate type to the moderate carbonate type from the recharge area to the lake area. The major source of ions in lakes is the weathering products of carbonate rocks, followed by evaporite and silicate solutes. The enrichment of lithium in salt lakes is mainly related to the contribution of rivers, followed by geothermal-related cold springs, and early sedimentary carbonate minerals may also make potential contributions. These findings provide a scientific basis for the mechanism of lithium enrichment, as well as for the further development and evaluation of lithium resources.