Distribution characteristics and resource potential evaluation of lithium in geothermal water in China

Objective In recent years, lithium has become a key mineral in the world's major economies, as demand has grown rapidly in the emerging and low-carbon technology industries. Especially under the "carbon peaking and carbon neutrality" goals, the demand for lithium resources is also becoming more urgent in China, but the security of lithium supply seriously restricts the development of new energy industry. At present, our lithium resources are mainly developed by the brine type and pegmatite type, but the geothermal brine type also has a certain resource potential. Therefore, it is necessary to study the distribution characteristics of lithium element in geothermal water.Methods Based on the results of investigation and study of geothermal water in China by predecessors, this paper introduces and discusses the distribution characteristics of lithium content in geothermal water, influencing factors, lithium extraction technology of geothermal water and geothermal exploration technology.Results It analyzed the lithium content of geothermal water in the main heat storage of 30 provinces and cities, and actually calculated that the annual discharge of lithium metal in the 1989 geothermal water was 789t, and estimated that the annual discharge of lithium metal in the geothermal water was 3233t, indicating that the geothermal water lithium resources have certain potential.Conclusions It is found that the main factors influencing the lithium content of geothermal water are the characteristics of surrounding rocks and thermal reservoir rocks, temperature, water-rock interaction, etc. It is also found that lithium isotopes have good potential in tracing the sources of geothermal systems, water-rock interactions, and material sources in continental areas. Lithium-rich geothermal water enrichment mechanism in China is mainly divided into the Himalayan geothermal belt type and Sichuan basin type, the former is related to the type in the crust remelting magma upwelling, while the latter is related to the dissolution and filtration of gypsum and halite in the strata. In addition, it is pointed out that the future prospecting direction of lithium-rich geothermal water in China will be concentrated in the Tibetan Plateau, Sichuan Basin, Jianghan Basin and oil (gas) field water. "Simultaneous exploration of geothermal water and lithium" and "simultaneous mining of geothermal water and lithium" to maximize the utilization of resources, and multiple geothermal exploration technologies will also contribute to the development of geothermal industry.