Novel process for the extraction of lithium carbonate from spent lithium-containing aluminum electrolytes by leaching with aluminum nitrate and nitric acid

A hydrometallurgical process was developed to extract lithium from a spent lithium-containing aluminum electrolyte, reduce the stacking of spent aluminum electrolyte, and recover the valuable elements. In this study, we extracted lithium from an electrolyte using the following three steps: 1) leaching with HNO3 − Al(NO3)3, 2) neutralizing the leachate obtained in the first step, and 3) precipitating the lithium carbonate. A lithium extraction efficiency of 88.0% could be achieved after a leaching time of 6 h, at a leaching temperature of 80 °C and an Al/F molar ratio of 1:6. During the process of neutralization, Al3+ and F− was precipitated as Al2((OH)0.46F0.54)6(H2O). The obtained Li2CO3 with a high purity of 98.8%.