Gallium recovery from Bayer's liquor using hydroxamic acid resin

Abstract

Gallium, which is extensively used in the production of semiconductor materials, is present at the parts per million level in Bayer's liquor. The low concentration of gallium in the liquor, along with the high concentration of aluminum, prompted the use of chelating ion exchangers as an alternative separation process. A chelating ion exchange resin with hydroxamic groups attached to the copolymer of acrylonitrile-divinylbenzene has been prepared by suspension polymerization followed by hydrolysis and chelation with hydroxylamine hydrochloride. Adsorption studies of gallium, using the above hydroxamic acid resin, were carried out. Adsorption was dependent on particle size of the resin and optimum conditions are determined for obtaining 0.3-to 0.5-mm particles by varying the composition of the emulsion, using a secondary polymerization technique, and adding of diluents. Acrylic acid, as a diluent in the copolymer matrix, was found to increase the particle size and stability of the resin. IR studies, carried out for the products obtained at various stages, confirmed the conversion of polymer to resin with a hydroxamic acid group and its complex formation with gallium. Both batch and column studies were carried out for the determination of the capacity of the resin with synthetic Bayer's liquor containing gallium and commercial Bayer's liquor. Scaledup column studies were carried out with commercial Bayer's liquor to test the cyclability and stability of the resin. It was observed that chelated ion exchange resin could be recycled up to 30 times. The optimal liquid to solid phase ratio was found to be 1:12.

Distribution of Selected Trace Elements in the Bayer Process

“…This is in accordance with the range of V saturation levels in Bayer liquors reported elsewhere in publications (100-2800 mg/L V) [10,65,69,71]. Authier-Martin et al refer to earlier studies indicating that V is about 30% soluble during Bayer digestion [9].…”

“…The Ga digestion reaction is described by Equation (2) [9]: Ga accumulates in process liquors, achieving saturation at levels exceeding 300 mg/L. This is about the average of that reported across earlier publications (60-600 mg/L Ga), yet typically shown values remain between 100-200 mg/L Ga [65][66][67][68][69][70]. The present Ga saturation levels are prospective for economic extraction given that Frenzel et al suggest a conservative cut-off concentration for profitable production of Ga from process liquor being 240 mg/L [8].…”

Uniform macroporous amidoximated polyacrylonitrile monoliths for gallium recovery from Bayer liquor

“…Compared with the above methods, chelating or ion exchange resin, also named adsorption resin, is currently the best recovery method, [15][16][17][18] which results from its fast adsorption speed, good stability, and ease of recovery and separation. Among all kinds of adsorption resins, the resins containing amidoxime groups have the best adsorption performance on gallium.…”

The structure of hyperalkaline aqueous solutions containing high concentrations of gallium – a solution X-ray diffraction and computational study

“…The separation of gallium from aluminium is done by standard methods. 1 Gallium is a typical semiconductor and most of its industrial use is due to that. Since both aluminium and gallium are in the 13 th column of the periodic table, the physicochemical characteristics are also very much alike (except that aluminium is not a semiconductor).…”

“…Our knowledge about the structure of Ga(III)-bearing species forming in strongly alkaline (pH > 13) solutions is ARTICLE Journal Name 2 | J. Name., 2012, 00, [1][2][3] This journal is © The Royal Society of Chemistry 2012 relatively little. Besides Ga(OH) 4 -, the first possible candidate is the dimeric (OH) 3 Ga-O-Ga(OH) 3 2-; a solution species analogous to this has been observed in alkaline aluminate solutions.…”