Abstract:Process of cyclic alkali leaching and cooling crystallization of aluminum hydroxide was proposed to separate positive active material and aluminum foil current collectors from spent lithium-ion batteries. The results show that average aluminum content in alkali leaching residue is 0.78% with average aluminum extraction rate of 90.98% under the optimum conditions including leaching at 90 ℃ for 2 hours and crystallization at 40 ℃ for 40 hours with crystal seeds dosage of 1.5 times. The cooling crystallizing precipitation product is gibbsite containing 32.14% of Al, 0.15% of Li, 0.04% of Co, and 0.51% of Na respectively, which could be used as raw materials for aluminum recovery. Mother liquor after cooling crystallization contains about 22.08 g/L of Al, which can be returned to alkali leaching stage for recycling.