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

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.