Comparative study of alkaline and acid-based processes for lithium recovery from Mapatizya lepidolite

The increasing demand for lithium in energy storage systems requires efficient extraction from alternative resources such as lepidolite. This study compares alkaline pressure leaching, alkaline roasting, and acid baking for lithium recovery from Mapatizya lepidolite (1.54 wt.% Li), characterised as a lithium-rich aluminosilicate dominated by trilithionite and quartz. Alkaline pressure leaching achieved the highest recoveries, reaching 95.5% with NaOH at 240 °C. Alkaline roasting also yielded significant recoveries (95% with NaOH at 500 °C and 2.5 g/g feed) and was selected as the best option because of its potential for simpler process operation, lower capital costs, and greater scalability. In contrast, acid baking produced lower recoveries (∼82%).