Recovering gallium from residual Bayer process liquor.

Gallium is normally obtained by direct electrolysis as a by-product from Bayer process residual liquor at an aluminium processing plant. However, to permit any net accumulation of the metal, the gallium concentration must be at least about 0.3 g/l in the liquor. A continuous process of extraction with organic solvents and rhodamine-B, followed by a re-extraction step into aqueous media is described. The final product is a solid containing up to 18 wt.% Ga in a solid mixture of hydroxides and oxides of gallium and aluminium. This product can then be electrolysed to recover the gallium more efficiently.
Gallium is normally obtained by direct electrolysis as a by-product from Bayer process residual liquor at an aluminium processing plant. However, to permit any net accumulation of the metal, the gallium concentration must be at least about 0.3 g/l in the liquor. A continuous process of extraction with organic solvents and rhodamine-B, followed by a re-extraction step into aqueous media is described. The final product is a solid containing up to 18 wt.% Ga in a solid mixture of hydroxides and oxides of gallium and aluminium. This product can then be electrolysed to recover the gallium more efficiently.