On March 29, 2024, the EPC general contract for the construction of the 40,000 ton/year basic lithium salt integration project of chemical giant Qinghai Salt Lake was officially signed.

It is reported that the signing ceremony of the general contract was held at China Chengda Engineering Co., Ltd., where Chengda Company and the person in charge of the Qinghai Salt Lake project signed the contract on behalf of both parties, marking significant progress in the project.

With a total investment of about 7.098 billion yuan, the project is located in Cha′erhan Salt Lake, Golmud City, Qinghai Province. It includes an annual production of 20,000 tons of battery grade lithium carbonate and 20,000 tons of lithium chloride. WIth potassium fertilizer rich brine as feedstock, it adopts adsorption method to extract lithium chloride from old brine. involving five process units: salt field and storage tank, adsorption lithium extraction, membrane refining concentration, reaction precipitation lithium, and lithium chloride.

In terms of engineering, it mainly includes lithium extraction workshop, refining and concentration workshop, lithium chloride workshop, lithium carbonate workshop, and supporting public and auxiliary engineering.

Under the brine transportation and storage project, the tail liquid (old brine) discharged from the potassium fertilizer company′s salt fields is transmitted back to the processing plant for lithium extraction and the tail liquid (old brine tail liquid) extracted from the processing plant is transported to the old brine tail liquid discharge channel, relying on the existing salt field old brine discharge system of the potassium fertilizer company to return to the mining area of the potassium fertilizer company for utilization. This mainly includes a 7.6km potassium fertilizer tail liquid conveying channel, a brine conveying pump station, a potassium fertilizer tail liquid storage tank, a potassium fertilizer tail liquid front tank, a 1.16km low level brine conveying channel, a 22km dam, and a potassium fertilizer tail liquid adsorption tail liquid discharge pipe channel.

Salt Lake Corporation owns the mining rights of approximately 3700 square kilometers of the largest soluble potassium magnesium salt deposit in China. Currently, its main products are potassium chloride and lithium carbonate. In 2022, the annual production and sales of potassium chloride reached 5.8 million tons and 4.9411 million tons respectively, with a domestic potassium fertilizer market share of over 70%. The annual production and sales of lithium carbonate were 31000 tons and 30000 tons, respectively.

Boasting mature technology for lithium extraction from salt lakes, Salt Lake Corporation has an annual production capacity of 30,000 tons of lithium carbonate project with low product costs and remarkable advantages. Its subsidiary, Lanke Lithium Industry, has also achieved large-scale production. This project will strengthen cooperation with Lanke Lithium Industry in project construction, personnel and experience to advance the coordinated development of the company′s lithium industry.

The annual production of 40,000 tons of basic lithium salt integrated project will further promote the development of the lithium industry towards serialization, high quality, and diversification. After decades of effort in exploration and innovation, Salt Lake Corporation has successfully broken through the adsorption method for lithium extraction from brine with ultra-low content and ultra-high magnesium lithium ratio. The 30,000-ton lithium carbonate demonstration device has laid a solid technical foundation for project construction, which will enable more efficient utilization of lithium resources in Salt Lake.