Review on Progress of Lepidolite Flotation Collectors and Depressants

With the increasing demand for lithium resources in recent years, the flotation research of lepidolite becomes more and more important as it is a key supplementary source of lithium resources. However, lepidolite usually coexists with gangue minerals such as calcite, muscovite, feldspar and quartz, which makes it difficult to separate them. Herein, based on the analysis of the crystal properties of lepidolite, this review highlights recent research progress in flotation collectors and depressants of lepidolite. At present, the main flotation collectors of lepidolite mainly include amine cationic collectors (primary amine, secondary amine, quaternary ammonium salt, ether amine and Gemini), the combination of amine cationic collectors and anionic collectors in a certain proportion. Flotation depressants mainly aim at the Si-containing and Ca-containing gangue minerals, which could be divided into inorganics (water glass, sodium hexametaphosphate and so on), organics (oxalic acid, tannin and lignin) and combined depressants. It is pointed out that the future research focus in the field of lepidolite flotation is mainly on the following three points: (1) the synthesis of novel lepidolite collectors; (2) basic research on the adsorption mechanism of mixed cationic/anionic collectors at the lepidolite/water interface; (3) the combination of the inorganic and organic depressants for the inhibition of calcareous and siliceous gangues and the correlated mechanisms.