Lithium Isotopes System Acquired in Qaidam Basin

Lithium isotopes system, a sensitive geochemical tracer, can be used to track a wide range of geological processes and sources. Recently, sources and a proposal for comprehensive exploitation of lithium brine deposits in the Qaidam Basin on the northern Tibetan Plateau depending on the lithium isotopes have been unveiled by researchers. And the thorough understanding of the origin and distribution of lithium brine deposits is the foundation for lithium resource exploration, development, and utilization.

Lithium has attracted much attention in the 21st century as a new energy source and strategic resource. Its role becomes even more prominent along with the development of Li-battery technology and its application in the field of controlled nuclear fusion, its role has become more prominent. The current international demand continues to grow at rates of 7% to 11% per year. The metal is therefore known as "the energy metal of the 21st century" and "clean energy of the 21st century". It is predicted that Li will become as important as a strategic resource as oil is currently.

salt lakes in the Qaidam Basin image

Lithium resources are mainly found in salt lakes and granitic pegmatite deposits, among which salt-lakere sources account for 69% of the global reserves and 87% of the global reserve base. China is rich in lithium brine resources, with lithium reserves ranking third in the world behind Bolivia and Chile, and accounting for about 30% of the world reserves. This resource is mainly distributed on Qinghai-Tibet Plateau. Among these reserves, the brine deposits in the Basin are very rich, with large reserves, high grades, and great potential economic value. According to statistics, the Li in the Basin accounts for more than 80% of China's total resource reserves.

Therefore, the geochemical genesis and material source of lithium resources in the salt lakes of the Basin are necessary conditions for the sustainable and green development of the resources in the salt lakes of the Basin, and will also be important for the stable production and development of large-scale salt-lake industries in China.

Recently, the team of the Laboratory of Earth Surface Processes and Chemical Weathering in conjunction with the Institute of Geochemistry Chinese Academy of Sciences and the Qinghai Institute of Salt Lakes of Chinese Academy of Sciences systematically sampled and analyzed 31 typical salt lake samples in the Basin. Data on lithium isotopes of salt lakes in the Basin were obtained. Related research results were published in Ore Geology Reviews

salt lake in Qaidam Basin image

The data show that the lithium isotope geochemical characteristics of the salt lakes in the Qaidam Basin show three distinct zones, and the lithium isotopes of each zone are significantly different. Researchers further discussed the structure and other data of the Basin, and revealed that the structure of the Basin is the main factor that causes the lithium isotopic difference in salt lakes.

The salt lake in the western Qaidam Basin is currently the main lithium mining and processing area in China. The thesis focuses on the in-depth discussion of the source of lithium in the salt lake in this region. Through comprehensive analysis of different samples (hot springs, river water, rocks, lake water, and intercrystalline brine), it is found that the lithium in the salt lakes in this area mainly comes from the hot springs in the Hoh Xil region that are continuously supplied by the flood river system.

Weathering and leaching of Li from Tertiary salt deposits, weathering and leaching from Li-rich parent rock, freshwater, deep groundwater via fractures (oil field brines, hot springs, etc.), and recycled brine are possible sources of lithium in the brine lakes of the Qaidam Basin. The article suggests that in the process of expanding production, companies must consider adjusting production methods to avoid the wasting of lithium resources while producing potassium fertilizer.