Recovery of lithium from coal gangue utilizing acid baking followed by water leaching

With the rapid development of the lithium (Li)-ion battery industry in electric vehicles (EVs) and electronic devices, coal-based Li ore is expected to be a new-type Li resource to meet the rapidly growing demand for Li. However, the traditional Li extraction process involves high temperature to activate minerals. Herein, a low-temperature sulfuric acid baking followed by water leaching was investigated in this study. The influences of baking and leaching conditions on Li leaching rate were explored in detail. Under the optimal conditions of 70 wt% H2SO4, baking temperature 180 degrees C, baking time 1 h, leaching temperature 25 degrees C, and leaching time 1 h, the Li leaching rate reached 84.42%. In addition, the sequential chemical extraction, XRD, and SEM-EDS results indicated that Al-Li-containing minerals were converted to soluble minerals during the baking process with sulfuric acid and then were extracted through water leaching into the solution.