High-efficiency, environment-friendly extraction of lithium from waste LAS glass-ceramics by roasting with KOH at low temperature

Recovering lithium from waste lithium aluminum silicate-based glass ceramics (LASGC) is one of the effective strategies to alleviate the shortage of lithium resources. Lithium extraction currently faces the problems of high energy consumption (>1000 °C) and secondary pollution. It is urgent to develop a high-efficiency, environment-friendly and low-temperature lithium extraction technology. In this work, KOH roasting combined with a water immersion strategy including lithium extraction, desilication, lithium precipitation, and the synthesis of silica hydroxyl intermediates was adopted to study the feasibility and advantages of lithium extraction from waste LASGC. When the roasting temperature is as low as 300 °C, the recovery rate of lithium can reach above 90 %, and the high-value conversion of solid waste in the whole process can be realized. In addition, the mechanism of lithium extraction was clarified through a series of characterizations. This work may provide a valuable reference for the efficient recovery and utilization of secondary lithium sources.