Purification of Lithium Carbonate from Sulphate Solutions through Hydrogenation Using the Dowex G26 Resin

Purification of lithium carbonate, in the battery industry, is an important step in the future. In this experiment, the waste lithium-ion batteries were crushed, sieved, leached with sulfuric acid, eluted with an extractant, and finally sulphate solutions were extracted, through selective precipitation. Next, sodium carbonate was first added to the sulphate solutions, to precipitate lithium carbonate (Li2CO3). After that, lithium carbonate was put into the water to create lithium carbonate slurry and CO2 was added to it. The aeration of CO2 and the hydrogenation temperature were controlled, in this experiment. Subsequently, Dowex G26 resin was used to remove impurities, such as the calcium and sodium in lithium carbonate. Moreover, the adsorption isotherms, described by means of the Langmuir and Freundlich isotherms, were used to investigate the ion-exchange behaviors of impurities. After removing the impurities, the different heating rate was controlled to obtain lithium carbonate. In a nutshell, this study showed the optimum condition of CO2 aeration, hydrogenation temperature, ion-exchange resin and the heating rate to get high yields and purity of lithium carbonate.