Analysis of the Hydrochemical Characteristics and the Evolutionary Stages of Brine in Mahai Salt Lake in the Qaidam Basin

The objective of this study was to contribute to the understanding of the hydrochemical processes and evolution of brine in the Qaidam basin, in order to provide a theoretical basis for the application of brine resources in the region. The hydrochemical characteristics and evolutionary stages of brine in Mahai Salt Lake were investigated using factor analysis on brine chemistry data from 109 sampling points. Our results showed that the centre of the Salt Lake has the highest concentration of total dissolved solids (TDS), and the hydrochemical type of brine is chloride-magnesium. The brine at the centre of the lake is at the later stages of mirabilite precipitation, and the content of K+ is relatively stable. Comparatively, the hydrochemical type of brine in the slope area of the Salt Lake is Cl-Na-Mg, and is at the early stages of brine evolution. It is of guiding significance to further develop and utilize brine resources, especially to evaluate its resource development potential.