Recovery of lithium from LiAlO2 in waste box sagger through sulfation to produce Li2SO4 and sequential wet conversion to Li3PO4, LiCl and Li2CO3

Abstract

To supplement the increasing demand for lithium (Li) resources dictated by the growing market for lithium-ion batteries (LIBs), this study aimed to secure lithium carbonate (Li2CO3) using a waste box sagger generated from the process of manufacturing cathode materials for LIBs. Lithium was recovered through sulfation and subsequent wet conversion into high-purity Li2CO3. Lithium extractability (93%) from the waste box sagger powder was determined by the sulfation reaction using 5 M sulfuric acid (H2SO4) and distilled water (H2O) leaching of the resultant. The precipitation efficiency (85%) of Li into lithium phosphate (Li3PO4) in extracted Li solution was established using a sodium hydroxide (NaOH) and phosphoric acid (H3PO4) mixture. The maximum conversion efficiency (99%) of Li3PO4 to lithium chloride (LiCl) solution was calculated using a reflux method with calcium chloride (CaCl2) solution at a solid (g)/liquid (L) ratio of 100. The highest Li+ concentration reached 50,800 mg/L at a solid/liquid ratio of 400 and Cl/Li molar ratio of 0.95 in the range of tested conditions. Finally, high-purity Li2CO3 (99.8% in metal basis) was produced from the obtained Li solution through purification using NaOH, followed by carbonation using sodium carbonate (Na2CO3). The proposed method demonstrates the feasibility of securing a Li resource by recycling waste box sagger instead of disposing them as a designated waste.