Verfahren zur Gewinnung von Gallium, insbesondere fuer Halbleiterzwecke

In a process for recovering gallium from liquors containing sodium gallate and sodium aluminate, sufficient active finely divided aluminium is added to displace the gallium from the sodium gallate and to alloy therewith to form an Al-Ga alloy which may be separated by filtration or centrifuging. The Al may be ground Al and is preferably ground in the presence of aluminium alkyls in the absence of air and moisture. The gallium may be separated from the alloy by chlorinating the alloy to obtain a trichloride mixture from which the GaCl3 may be selectively extracted, forming alkali metal gallate therefrom and then electrolysing this to deposit Ga. An alternative method is to use the alloy as the anode in an electrolytic cell using an organo-aluminium complex salt electrolyte, the gallium being recovered from the anode residues by further electrolysis. Fairly pure liquid gallium may also be obtained by treating the alloy with alkali liquor or dilute acid. Specifications 981,685 and 1,001,482 are referred to.