The pilot-scale experiment of extracting lithium from original halogen by adsorption has been officially launched to promote the construction and development of lithium resources in South American salt lakes.

Recently, the company signed a cooperation framework agreement with Jiangsu Jiuwu Hi-Tech Co., Ltd. (hereinafter referred to as "Jiuwu Hi-Tech") on the pilot-scale study of lithium extraction from Argentine salt lake adsorption coupled membrane brine. Hand in hand to carry out technical research on the development of lithium resources in South American Salt Lake. According to the agreement, the two sides will complete the design, manufacture and on-site compliance of the pilot plant as soon as possible, and formally carry out the pilot test.

The company has two salt lake projects in Argentina, and its resources and endowment have significant advantages over domestic salt lakes, such as high lithium concentration and low impurity content. The company has started the Angeles Salt Lake project to expand production to 27500 tons of lithium carbonate equivalent, which is currently the fifth largest salt lake development project by Chinese enterprises in the world.

The purpose of this cooperation agreement is to develop a new lithium extraction technology according to the characteristics of Argentine salt lake brine. According to the selection of salt lake brine quality, the most advanced adsorption coupling membrane process and the technical route of directly extracting lithium from underground brine are proposed, on the one hand, the direct extraction of lithium from traditional salt field construction can be saved, and the production time is at least 18 months faster than the traditional salt field method, which greatly shortens the construction cycle of the follow-up project; on the other hand, it can also effectively reduce the project investment and construction cost, and the advantage is very obvious.

Schematic diagram of lithium extraction process

This pilot plant adopts integrated container lithium extraction device, which includes adsorption, reverse osmosis concentration, high pressure nanofiltration, chelating resin impurity removal, evaporation concentration, reaction lithium precipitation and other processes, which can realize the whole process from raw brine to battery-grade lithium carbonate products.

In the adsorption section, the raw halogen lithium extraction adsorbent independently developed and produced by Jiuwu Hi-Tech is the core "element" for the separation of sodium and lithium, combined with super-third generation rotating moving bed technology, in order to solve the key problem of sodium and lithium separation from salt lake brine. It can achieve a very high lithium ion recovery rate, the theoretical recovery rate of the adsorption section can reach more than 90%, and the lithium content of the adsorption tail halogen can be less than 20 ppm, and the ratio of sodium to lithium can be less than 1, which greatly reduces the difficulty of subsequent concentration and purification. The original halogen lithium extraction adsorbent adopts unique powder production technology, the powder has high crystallinity, extremely low dissolution rate, moderate particle size and uniform distribution, and is shaped by special granulation process with special polymer material as skeleton, the granulation skeleton is dense outside and sparse inside, the powder running rate is low, and the adsorption capacity is more than 4 mg/g. The super-third-generation rotating moving bed technology is used for the first time in the field of lithium extraction from salt lake. it is the most advanced continuous separation device at present, which can realize automatic operation and greatly reduce the intensity of manual operation. The valve core design and manufacturing process are more advanced, which can avoid the key technical problems such as pipeline blockage and multi-channel valve wear caused by brine crystallization, which provides a technical guarantee for the follow-up large-scale lithium extraction industrialization.

The design recovery rate from adsorption section to membrane section in this pilot test is expected to reach 88%, which is much higher than the traditional lithium extraction process in South America. The pilot test results will provide basic process data for the company to expand production, which is an important step for the company to realize 27500 tons of lithium carbonate / year large-scale production.