Development of a co-precipitation process for the preparation of magnesium hydroxide containing lithium carbonate from Li enriched brines

Abstract

Ongoing research to develop a new generation of materials to achieve a more reliableand higher energy density lithium-ion batteries has attracted working groups attentionworldwide in academia and industry. Products like lithium carbonate or lithium hydroxide arefundamental as the main feedstock for future materials. Recently, metal-atom substitutedcathode materials with various metals has proved to improve the life-time, stability andperformance of cathodes and consequently of the batteries. In this regard, this publicationdescribes an approach to remove calcium impurities from industrial Lithium-rich brines withoxalic acid. Moreover, the present magnesium is reduced by the precipitation of magnesiumhydroxide in a controlled manner in order to obtain a Lithium-enriched brine with a welldefinedmagnesium concentration in the absence of calcium. Finally, a process is presented toproduce high purity lithium carbonate with controlled concentrations of magnesium between1 % to 3 % as magnesium hydroxide. The magnesium hydroxide containing lithium carbonateis produced in a co-precipitation step, where initially the magnesium hydroxide is precipitatedand subsequently the lithium carbonate is precipitated in a one-pot process.