Method for extracting lithium from brine to prepare battery-grade lithium carbonate by ion exchange method

Abstract

The invention relates to the field of lithium carbonate preparation, in particular to a method for extracting lithium from brine to prepare battery-grade lithium carbonate by an ion exchange method. The method includes the steps of 1), removing magnesium by a coprecipitation method; 2), adsorbing to extract the lithium by a manganese adsorbent; 3), preparing the battery-grade lithium carbonate, namely adding alkaline liquor into a desorption solution in the step 2), regulating a pH value to 7-12, producing manganese hydroxide precipitate, filtering the manganese hydroxide precipitate, concentrating filtrate until the lithium content reaches 20-30 g/L, filtering to remove sodium chloride, adding a saturated sodium carbonate solution to react, filtering, and subjecting filter cakes to water scrubbing so as to obtain the battery-grade lithium carbonate. The method has the advantages that hydrotalcite is obtained after magnesium removal, so that the problem of recycling the magnesium in the brine is solved; the content of various impurity ions in the desorption solution can be controlled effectively by removing the magnesium and extracting the lithium by adsorption sequentially, and then the battery-grade lithium carbonate is prepared.

Description

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AI Technical Summary

Benefits of technology

This technology allows for efficient removal or separation of magnetic metals from other materials like calcium oxides during production processes without causing damage. By combining this process with an ion exchange resin (IER) material called activated charcoal), it becomes possible to recover high quality lithiating chemical compounds made up mostly of cations and divancies. Additionally, when combined with another step involving selective precipitator media, these new products have improved properties such as better heat resistance compared to traditional methods. Overall, this technology helps create highly pure batteries at industrial scale while improving their overall effectiveness over existing technologies.

Problems solved by technology

This patented technology describes two main issues related to current methods used during lithiated redox flow cells (LiB). One problem addressed by this patent relates to the presence of excessive amounts of iron or calcium in these solutions that may affect their performance negatively. Another issue involves removing too much magnetic metal ions present in the system without compromising its ability to separate them efficiently.