Selective synthesis of LiOH from high-sodium concentration Li2CO3 mother liquor

The rational disposal of Li2CO3 mother liquor is especially critical with the rapid increase in lithium consumption. Most of the current processes are based on solvent extraction, which has still not been applied to practical industry due to their drawbacks. In this paper, a novel process for selective extraction of lithium from high-sodium concentration Li2CO3 mother liquor by NaF precipitation was proposed. 91.3% of lithium precipitated as LiF under the optimal conditions, such as NaF dosage of 1.1 times theoretical amount, temperature of 30 °C, and time of 2 h. Subsequently, the precipitation products were converted by Ca(OH)2. The conversion of LiF reached 89.9% and the liquid product obtained was LiOH solution with 7.5 g/L Li. The separation factor of Li/Na in the whole process reached 377. This novel process is an efficient, clean, and short process that provides a new idea for the selective synthesis LiOH from high-sodium concentration Li2CO3 mother liquor.