Recovery of valuable materials from spent lithium-ion batteries by mechanical separation and thermal treatment

In this paper, a mechanical separation and thermal treatment process is developed to recover valuable metals and graphite from the −0.25 mm crushed products of spent lithium-ion batteries (LiBs). Effect of key parameters for roasting such as the temperature and roasting time are investigated to determine the most efficient conditions for surface modification of the mixed electrode materials by roasting. The roasted mixed electrode materials are separated by flotation operation to recover the cathode material and anode materials respectively. The results show that most of the organic outer layer coated on the surface of the mixed electrode materials can be removed at the temperature of 450 °C for 15 min. After roasting treatment, the original wettability of LiCoO2 and graphite is regained. The −0.25 mm crushed products of spent LiBs can be separated into LiCoO2 concentrate and graphite concentrate by flotation process efficiently. The enrichment ratios of Co, Mn, Cu and Al are 1.35, 1.29, 1.25 and 1.19, their recovery rates are 97.66%, 93.66%, 90.14% and 86.29%, respectively. This process proposed for the recovery of valuable materials is simple and of high efficient for the spent lithium-ion batteries recycling industry.