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 reliable and higher energy density lithium-ion batteries has attracted working groups attention worldwide in academia and industry. Products like lithium carbonate or lithium hydroxide are fundamental as the main feedstock for future materials. Recently, metal-atom substituted cathode materials with various metals has proved to improve the life-time, stability and performance of cathodes and consequently of the batteries. In this regard, this publication describes an approach to remove calcium impurities from industrial Lithium-rich brines with oxalic acid. Moreover, the present magnesium is reduced by the precipitation of magnesium hydroxide in a controlled manner in order to obtain a Lithium-enriched brine with a well-defined magnesium concentration in the absence of calcium. Finally, a process is presented to produce high purity lithium carbonate with controlled concentrations of magnesium between 1% to 3% as magnesium hydroxide. The magnesium hydroxide containing lithium carbonate is produced in a co-precipitation step, where initially the magnesium hydroxide is precipitated and subsequently the lithium carbonate is precipitated in a one-pot process.