Review of technologies to extract lithium from hard rock lithium minerals

Lithium (Li) is becoming increasingly important for energy applications driven by rapid advancements in lithium-ion battery technologies, the move toward vehicle electrification, and increasing demands for grid energy storage systems. Although brine deposits are the main lithium source, the role of lithium-bearing minerals for producing lithium salts is expanding because of their widespread availability and historical market establishment. Methods of extracting lithium from ores fall into five key categories: acid leaching, alkaline leaching, salt roasting, pressure leaching, and chlorination roasting. Sulfuric acid leaching is particularly efficient for processing spodumene ores and is expected to maintain its lead amongst extraction techniques that use spodumene as the primary raw material. Additionally, a technique combining sulfuric and hydrofluoric acid has shown potential for lowering energy consumption compared with the conventional sulfuric acid process, but this benefit must be carefully weighed against the environmental and operational impacts of the use of fluorides. Pressure leaching has proven especially effective for treating lepidolite and has achieved high recovery rates of lithium and valuable by-products such as rubidium and cesium, yielding high-purity products. Although this method has advanced to.

commercial production, it is still under development and requires further research to improve its performance. Chlorination roasting is an alternative lithium extraction method that can directly process a variety of lithium ores with a high extraction efficiency. Despite substantial research dedicated to chlorination roasting, further studies are essential to determine its economic feasibility, environmental sustainability, and operational safety.