Recently three important methods for extracting lithium from salt lakes—adsorption, membrane, and extraction methods—have been industrialized in Qinghai and Tibet. With the increasing demand for lithium resources in the industry, the advantages of adsorption methods in the treatment of low-grade lithium resources and front-end brine are becoming more and more obvious. However, due to the characteristics of different salt lake resources, the design of adsorbents and supporting processes are mainly suitable for chloride-type salt lakes. It is urgent to develop new adsorbents and corresponding processes to deal with the extraction of other types of salt lake resources and low-grade lithium resources.
After years of scientific research, Qinghai Institute of Salt Lake has successfully prepared a series of lithium-ion adsorbents suitable for chloride-type, sulfate-type, and carbonate-type salt lakes through continuous optimization and upgrading. Through internal structure modification, surface structure modification, pore structure regulation, and other related work, the performance of the adsorbent has been comprehensively improved. Through different improved granulation methods such as extrusion, polymerization, and cross-linking, the hydrophilicity and the compressive strength of the adsorbent particles are improved. Finally, by use of the improved adsorbent particles, the adsorption tower and the corresponding process were developed and optimized, and the pilot experiment of the sulfate salt lake brine was completed. The patents of systemic technology have been formed, and the technical protection covers from the design, modification, and granulation of adsorbents, to the research of supporting equipment and the optimization of the process. The next step will be to actively cooperate with relevant enterprises to promote the transformation of results.
Optimization of internal structure and surface structure of lithium ion adsorbent particles
Mass preparation and pilot - scale process optimization of lithium ion adsorbent