effective parameters on high-purity lithium carbonate production from spent lithium-ion batteries

The use of lithium-ion batteries in electronic devices is growing rapidly. as a result, the demand for the consumption of lithium metal has increased. although spent lithium-ion batteries contain sources of precious metals, they seriously threaten human health and the environment. therefore, the recovery of lithium-ion batteries may prevent environmental pollution. the hydrometallurgy method was applied as the recovery process due to its high recovery efficiency, low energy consumption, and high reaction rate. it is widely used in the recycling process of spent lithium-ion batteries. in this research, instead of all reports concerning synthetic wastewater, industrial wastewater containing lithium was used as feed. effective parameters on lithium recovery in the form of lithium carbonate and its purity were the initial mass of solution to final mass of solution or concentration ratio, the mole ratio of sodium carbonate to lithium sulfate, raffinate usage, and the cooling effects. results showed that the optimum condition to achieve maximum purity and recovery of lithium carbonate was obtained at a concentration ratio of 15-20. at different tests with the mole ratio of sodium carbonate to lithium sulfate as 1, 1.5, and 2, the highest recovery efficiency was obtained at the ratio of 1.5. the use of sediment-free raffinate in the last stage also played a big role in lithium recovery. to use the raffinate solution, the raffinate must first be removed from the saturated state of sodium sulfate. then sodium carbonate becomes saturated in raffinate and is added to the original solution. under the above conditions, lithium carbonate was obtained with a purity of approximately 99% and a recovery of 65%. the combined process of evaporation with cooling was also a proper process for producing lithium carbonate. in this state, the purity and recovery of the final product were approximately 97% and 75%, respectively.