Process Method for Recovering Lithium from Lithium Precipitation Mother Liquor

Lithium is an important strategic resource, mainly existing in two forms in nature: solid minerals and liquid minerals. Among them, lithium resources in salt lake brine account for about 70% of the world's reserves.

The methods for lithium extraction from brine include precipitation, extraction, ion exchange adsorption, calcination leaching, and electrodialysis. The adsorption method is used to extract lithium chloride from salt lake brine for the preparation of lithium carbonate. As a low-cost and environmentally friendly green process route, its application prospects are very promising (the Haipu Salt Lake lithium extraction process can complete the entire process from small-scale testing to industrialization, and can adjust the process to prepare lithium hydroxide or lithium carbonate according to the raw materials required for different types of battery production).

However, in the process of extracting lithium chloride from brine using adsorption method to produce lithium carbonate, a considerable amount of lithium element is contained in the lithium settling mother liquor after the lithium settling reaction. If treated as wastewater, it will have a huge impact on the environment and cause significant lithium loss in the production process of lithium carbonate. Solving the problem of lithium settling mother liquor is a key link in the large-scale and continuous production technology of lithium carbonate products.

The traditional method for treating lithium precipitation mother liquor currently is to add hydrogen fluoride to produce lithium fluoride. The lithium extraction rate is only about 70%, and the lithium extraction mother liquor contains a large amount of fluoride ions, which causes great pressure on the environment.

If the lithium precipitation mother liquor is directly returned to the system for recycling: Due to the current addition of soda ash as a carbonizing agent in the lithium precipitation reaction process, the lithium precipitation mother liquor contains a considerable amount of sodium ions, chloride ions, and carbonate ions. Long term use in this way will inevitably lead to the enrichment of sodium ions, chloride ions, and carbonate ions in the entire system, especially the sodium ions added to the sodium carbonate during the lithium precipitation process do not have a system outlet, ultimately causing the lithium precipitation reaction to proceed in an environment with a large amount of sodium chloride, resulting in excessive sodium ions and chloride ions in the product lithium carbonate, which cannot meet production needs.

The lithium recovery process of lithium adsorbent supplier Haipu's lithium precipitation mother liquor utilizes the HPL900 resin product and supporting process developed by Haipu. Even in salt lake brines or lithium containing feed solutions with alkali metal and alkaline earth metal contents hundreds or thousands of times higher than lithium ions, HPL900 still has high selectivity for lithium. Through a single adsorption separation, the magnesium lithium ratio, sodium lithium ratio, and potassium lithium ratio can be reduced to less than 1:1.

HPL900 is suitable for lithium extraction from salt lakes, lithium precipitation mother liquor, lithium-ion battery recycling industries, and other lithium containing liquid materials.