Recovery of lithium from the effluent obtained in the process of spent lithium-ion batteries recycling.

A novel process of lithium recovery as lithium ion sieve from the effluent obtained in the process of spent lithium-ion batteries recycling is developed. Through a two-stage precipitation process using Na2CO3 and Na3PO4 as precipitants, lithium is recovered as raw Li2CO3 and pure Li3PO4, respectively. Under the best reaction condition (both the amounts of Na2CO3 and Li3PO4vs. the theoretical ones are about 1.1), the corresponding recovery rates of lithium (calculated based on the concentration of the previous stage) are 74.72% and 92.21%, respectively. The raw Li2CO3 containing the impurity of Na2CO3 is used to prepare LiMn2O4 as lithium ion sieve, and the tolerant level of sodium on its property is studied through batch tests of adsorption capacity and corrosion resistance. When the weight percentage of Na2CO3 in raw Li2CO3 is controlled less than 10%, the Mn corrosion percentage of LiMn2O4 decreases to 21.07%, and the adsorption capacity can still keep at 40.08 mg g-1. The results reveal that the conventional separation sodium from lithium may be avoided through the application of the raw Li2CO3 in the field of lithium ion sieve.