This study investigates geochemical characteristics and resource potential of water-soluble lithium in lithium-rich salt lake sediments from the Qaidam Basin, focusing on the East Taijinar Salt Lake and Bieletan area. Through X-ray diffraction (XRD), elemental analysis (ICP-OES), and laser particle size analysis (LPSA), sediment samples were analyzed to assess mineral composition, lithium distribution and its occurrence forms. Results reveal distinct vertical zonation: lithium, boron, and potassium peak in clay-rich layers, contrasting with lower concentrations in halite-dominated layers. Regional patterns indicate that lithium enrichment in sediments aligns closely with brine, centered around Yiliping and East/West Taijinar Salt Lakes. Water-soluble lithium primarily originates from weak adsorption on clay minerals, with secondary contributions from intercrystalline brine, halite fluid inclusions, and gypsum dissolution. The clay layers exhibit lithium concentrations exceeding industrial grade and favorable Mg/Li ratios, comparable to brine mining standards. Co-enrichment of boron (415 ppm) and potassium highlights multi-resource potential. These findings highlight sediments as lithium reservoirs, which can serve as a sustainable potential supplement during brine depletion and enhance resource resilience in the Qaidam Basin. This study provides critical insights into lithium migration, enrichment mechanisms, and strategic resource management in evaporitic systems.

An eco-friendly flotation process is of great significance to the green and sustainable development of the mining industry. The purpose of this study is to improve the traditional flotation process. Novel reagents, alkyl ether amine (Alkyl carbon chains with a length of 12 are simply referred to as DOEA) as collector and carboxymethyl starch (CMS) as depressant, were used for flotation uAlkyl ether aminender lower temperature, which did not need to heat the tonnage of pulp and reduced the energy consumption. The micro-flotation tests were carried out with three main minerals (quartz, hematite and magnetite) contained in Qidashan (Anshan, China) iron ore at room temperature in winter (18 °C). The bench-scale tests were carried out with flotation feed (mixture of strong magnetic concentrate and weak magnetic concentrate) from the Qidashan flotation workshop at room temperature (18 °C). And the industrial tests were carried out in the flotation workshop of Qidashan Concentrator of Anshan Iron and Steel Co., Ltd. The temperature of the pulp was 17.5~19.7 °C. The results of micro-flotation tests showed that the floatability of the three minerals under the DOEA system decreased in the following order: quartz > hematite > magnetite. The addition of CMS increased the floatability difference between quartz and ferric oxide minerals. DOEA and CMS could effectively separate quartz and ferric oxide minerals at room temperature in winter. The feasibility of the application of DOEA and CMS in Qidashan iron ore was verified by bench-scale tests, and the pulp circulation process was simulated by locked-cycle tests. The results of bench-scale tests showed that under the conditions of CMS dosage 200 g/t, DOEA dosage 150 g/t, and pulp temperature 18 °C, the iron grade of flotation concentrate was 66.54% and iron recovery was 78.37%. The industrial test results showed that the modified flotation process could continuously output qualified iron concentrate without heating the pulp. Compared with the on-site flotation process, it was found that the modified flotation process could save USD 6,460,100 per year. This technology could significantly reduce the energy consumption of iron ore reverse flotation, reduce the carbon emissions generated by heating tons of pulp, and achieve cleaner production.