Extraction and purification process of gallium

Gallium, as a rare metal, occupies an important position in many emerging high-precision fields. This paper introduced several conventional processes of gallium extraction and purification. Gallium has a low abundance in the earth’s crust and is usually associated with aluminum and zinc, which is usually recovered as a byproduct. Acid or alkali leaching is first used to extract gallium from ores or secondary resources. And then ion exchange, fractional precipitation, and solvent extraction are generally applied to enrich gallium from lixivium, and finally crude gallium (99.99%) can be obtained by electrowinning, which is the raw material for further purification. Gallium has a low melting point and a high boiling point, and the distribution ratios of gallium and impurity elements in different phases are different, which is the theoretical basis for the purification. Therefore, the high-purity gallium (99.999%~99.999 999%) can be prepared by electrorefining, partial crystallization, single crystal growth, zone smelting, vacuum distillation and vacuum pyrolysis processes.