Gallium extraction process from gallium-containing solutions of alkali metals are less frequently airborne

摘要

Gallium is extracted from alkali solns. using electrochemical redn. with the aid of liq. metals. Redn. occurs in an alternating electromagnetic field. The process is pref. undertaken using (a) liq. Ga; or (b) contg. 0.05-0.5% Al and possibly 0.1-10% Zn. The liq. metal may be polarised to form a cathode, using direct current of 0.001-0.1 A/cm2. If the alkali solns. contain other substances which would impede the extn. of Ga, the substances are pref. reduced and removed from the soln. by settling or filtration prior to Ga extn.; the reduced substances can be pptd. by adding an alkaline earth element. Used in winning Ga from solns. obtd. in processing bauxite or nepheline. The Ga can be used e.g. in semiconductor cpds., dental alloys, or as conductors of heat or electricity. There is continuous prodn. of high purity Ga, where the magnetic field disturbs the film on the liq. metal cathode, improving the yield of Ga.