Characterization and Resource Potential of Li in the Clay Minerals of Mahai Salt Lake in the Qaidam Basin, China

Abstract

The strategic importance of lithium in global development has become increasingly prominent due to the rapid growth of the new energy automotive industry and the continuous advancements in controllable nuclear fusion technology. Lithium minerals in salt lakes possess advantageous characteristics, such as abundant reserves, environmental sustainability, and economic viability. Furthermore, with ongoing improvements in the lithium extraction process, the availability of lithium minerals in salt lakes is expected to further increase. The Qaidam Basin Salt Lake in China has served as the location for the establishment of numerous lithium carbonate production enterprises, resulting in a lithium carbonate production volume of 7 × 104 t/yr in 2022. How to meet the growing need for lithium resources has become an enterprise focus. Nevertheless, there are large amounts of clay minerals in and around the bottom and periphery of the salt lake in the Qaidam Basin, and whether these minerals are of exploitable value, regardless of the state of the occurrence of lithium resources, remains unexplored. To ascertain the attributes, extent, and distribution of the lithium occurrence within the clayey layer of the Qaidam Basin, as well as to assess its resource potential, a total of 87 drill holes were conducted within a designated area of the Mahai Basin, which is a secondary basin in the Qaidam Basin. The subsequent analysis encompassed the examination of the lithium content within the clay minerals, the mineral composition of the clay, and, ultimately, the evaluation of the resource potential within the region. Compared with Quaternary salt lake deposits, brine deposits in gravel pores, and the Paleogene–Neogene Li-bearing salt deposits that have been studied, it is suggested that this is a novel form of a clay-type sedimentary Li deposit within the Qaidam Basin. The findings of this research will serve as a fundamental basis for future endeavors pertaining to the exploration and exploitation of lithium deposits within salt lake areas.