Hydrometallurgical preparation of lithium carbonate from lithium-rich electrolyte

Abstract Recovery of lithium from lithium-rich electrolytes has attracted worldwide attention because of issues related to the electrolytic production of aluminum and its environmental impacts. Lithium carbonate preparation from a lithium-rich electrolyte by H 2 SO 4 leaching, followed by removal of impurities and lithium precipitation with Na 2 CO 3 was investigated. About 98% Li leaching efficiency was achieved in 1 h using 6% H 2 SO 4 at 80 °C while maintaining a liquid-to- solid ratio of 2:1. Li 2 SO 4 in the resulting leach solution was sequentially purified by NaOH addition to an end pH of 11 and then addition of 3 g/L ethylenediaminetetraacetic acid. Li 2 CO 3 of 99.5% purity was then obtained by precipitation with addition of 290 g/L Na 2 CO 3 at 95 °C for 50 min. This research is expected to improve understanding of requirements for the stable operation of electrolytic aluminum production and to potentially design processes for recycling of industrial lithium-rich electrolytes with high viability.