Lithium iron phosphate (LFP) batteries contain metals, toxic electrolytes, organic chemicals and plastics that can lead to serious safety and environmental problems when they are improperly disposed of. The published literature on recovering spent LFP batteries mainly focuses on policy-making and conceptual design. The production line of recovering spent LFP batteries and its detailed operation are rarely reported. A set of automatic line without negative impact to the environment for recycling spent LFP batteries at industrial scale was investigated in this study. It includes crushing, pneumatic separation, sieving, and poison gas treatment processes. The optimum retaining time of materials in the crusher is 3 minutes. The release rate is the highest when the load of the impact crusher is 800 g. An air current separator (ACS) was designed to separate LFP from aluminium (Al) foil and LFP powder mixture. Movement behaviour of LFP powder and Al foil in the ACS were analysed, and the optimized operation parameter (35.46 m/s) of air current speed was obtained through theoretical analysis and experiments. The weight contents of an Al foil powder collector from vibrating screen-3 and LFP powder collector from bag-type dust collector are approximately 38.7% and 52.4%, respectively. The economic cost of full manual dismantling is higher than the recovery production line. This recycling system provides a feasible method for recycling spent LFP batteries.
Keywords: Spent lithium iron phosphate battery; air current separator; automatic line; crushing; evaluation of automatic line; exhaust gas purification treatment.