Microwave-enhanced sulfate roasting for lithium extraction from lepidolite: A comprehensive study

Currently, the sulfate method used for roasting lepidolite to extract lithium presents several issues, including high energy consumption and low recovery efficiency. To address these limitations, we have employed microwave external fields to enhance lithium extraction and modified the roasting process. Microwave-enhanced roasting reduces heating time from 43 to 20 min, significantly lowering energy consumption compared to conventional roasting. Experimental results reveal that the optimal conditions are ferrous sulfate: potassium sulfate: calcium oxide: ore = 2:0.6:0.1:1, roasting temperature at 775 °C, and roasting time of 2 h, resulting in a lithium leaching efficiency of 95.9%. The study of dielectric properties shows that the addition of sulfate improves the microwave absorption characteristics of lepidolite, facilitating rapid heating in the microwave field. Additionally, uniform microwave heating reduces sample melting and adhesion, leading to looser clinker and improved lithium leaching efficiency. The microwave-enhanced sulfate roasting technology holds significant importance for the study of lithium extraction from lepidolite. We have employed microwave external fields to enhance lithium extraction and modified the roasting process. Microwave-enhanced roasting reduces heating time from 43 to 20 min, significantly lowering energy consumption compared to conventional roasting. Additionally, uniform microwave heating reduces sample melting and adhesion, leading to looser clinker and improved lithium leaching efficiency. [Display omitted]