US EPA

1769128 

Journal Article 

Recovery of gallium from Bayer liquor: A review 

Zhao, Z; Yang, Y; Xiao, Y; Fan, Y 

2012 

Yes 

Hydrometallurgy
ISSN: 0304-386X 

125 

115-124 

10.1016/j.hydromet.2012.06.002 

WOS:000307624700017 

Bayer liquor is the biggest raw material resource for
gallium production. Four kinds of methods have been developed to recover gallium from Bayer
solutions, including fractional precipitation, electrochemical deposition, solvent extraction,
and ion exchange. The fractional precipitation method is based on Al-Ga precipitation with CO2
and subsequent separation of Al and Ga with lime milk or sodium aluminate solutions. This
approach is more environmentally friendly and with low cost, but the process is complicated. The
electrochemical method includes both mercury cathode electrolysis and cementation. The
electrolysis with mercury cathode has been prohibited in most countries because of high toxicity
of mercury. Cementation is an electrochemical process realized by a displacement reaction between
gallium and reductants. such as sodium amalgam, aluminum and aluminum-gallium alloy. Solvent
extraction is an efficient method and by using Kelex 100 system about 80% of the gallium in Bayer
liquor can be extracted. However, the kinetics of the extraction process has been proved to be
very slow, which generally requires several hours. Ion exchange is the main method applied in
industry for gallium recovery from Bayer liquor. Duolite ES-346 and DHG586 exhibit good
extracting properties for gallium, and are used as industrial resins. Unfortunately, the co-
extraction of vanadium and the degradation of the amidoxime groups still remain as the main
problems during industrial application. In order to recover gallium from Bayer liquor
efficiently, further research and development are necessary. (C) 2012 Elsevier B.V. All rights
reserved. 

Gallium recovery; Bayer liquor; Electrolysis; Solvent extraction; Ion exchange