Ceramics-Silikáty 56, (1) 50 - 54 (2012)

In this study, processes based on roasting-leaching-crystallization steps and condensation-precipitation steps for Li₂CO₃ separation from spent Li/MnO₂ batteries and lithium-containing wastewaters were developed and verified on a laboratory scale. Spent Li/MnO₂ batteries were roasted under reduced pressure at 650^oC, which split the castings and deactivated the batteries by reduction of LiMnO₂ and MnO₂ with residual lithium metal and graphite to form MnO and Li₂CO₃. The resultant lithium carbonate was selectively solubilised in water with manganese remaining in the leach residue. Li₂CO₃ of 99.5 % purity was obtained after evaporation of 95 % water. Processing of lithium-containing alkaline wastewaters from the production of liquid rubber comprises condensation up to lithium concentration of 12-13 g/l Li and a two-step precipitation of lithium carbonate using CO₂ as a precipitation agent. Sparingly soluble Li₂CO₃ was produced in the second step at 95^oC, whilst most impurities remain in the solution. Obtained lithium carbonate products contained on average more than 99.5 % Li₂CO₃. The lithium precipitation efficiency was about 90 %.