Sustainable Mining and Metallurgy

Due to the rapid development of the battery industry, manganese sulfate, as the main raw material for the cathode material of lithium ion batteries, the requirements of its product quality and performance are getting higher and higher. A new method with low cost and large-scale separation of calcium from manganese sulfate solution is urgently needed. In this paper, the extractant P204 with low toxicity and low price to human body was used to extract calcium preferentially, and then the manganese saponification mechanism was used to inhibit the extraction of manganese ions. The calcium ions in manganese sulfate solution were removed without losing manganese ions, and a solution that meets the requirements of battery-grade high-purity manganese sulfate extraction was obtained. The effects of aqueous phase equilibrium pH, extraction temperature, O/A ratio, saponification rate and extraction stage on the separation efficiency of manganese and calcium were investigated. The experimental results show that the optimum conditions for calcium extraction by P204 are as follows: sodium saponification rate of 15%, pH value of 2, extraction temperature of 35℃, O/A ratio of 1∶1.5. After 30-stage manganese soap cross-flow extraction, the calcium concentration in the manganese sulfate solution after extraction was 0.02g/L, the calcium extraction rate was 94.47%, and the manganese loss rate was only 0.02%.