Abstract:The resource recovery of spent lithium-ion batteries has both environmental and economic benefits, however, the current research mainly focuses on the recovery of positive electrode, and there are relatively few reports on the recovery of anode graphite. A new process of low temperature ammonium hydrogen fluoride roasting-water immersion depth impurity removal of anode graphite was proposed, and the influence of different process conditions on the removal of impurities was systematically investigated. It is found that under the optimized conditions, the removal rate of lithium, nickel, cobalt, manganese, aluminum and copper in anode graphite reaches 99.78%, 99.84%, 99.99%, 99.94%, 95.18%, and 92.35%, respectively, and the purity of the graphite is higher than 99.9% after removal of impurities. In addition, the step-by-step removal of impurity ions in the leach solution was also studied. It is found that, firstly, through the joint use of the homoionic effect and solventing-out crystallization method, the removal rate of impurity aluminum ions in the leach solution can reach 88%, then through the reduction of iron powder treatment, the removal rate of copper ions in the leach solution reaches 76%. Then, through pH value regulation, cobalt, nickel, manganese and other metals in the leaching solution can be efficiently removed. Finally, ammonium hydrogen fluoride solid can be recovered from the leaching solution by evaporation and crystallization, so as to realize the recycling and recycling of the impurity removal agent.