Extraction of gallium from carbon concentrate - Aluminum industry waste

• Published in: Hydrometallurgy 2024-06, Vol.226, p.106289, Article 106289
• Main Authors: Losev, Vladimir, Buyko, Olga, Shimanskii, Alexander, Kazantsev, Yakov, Metelitsa, Sergey, Borodina, Elena, Li, Mingming
• Format: Article
• Language: English
• Subjects: Aluminum industry waste; Cementation; Gallium; Ion exchange; Leaching
• ISSN: 0304-386X
• DOI: 10.1016/j.hydromet.2024.106289

A complex approach to the extraction of gallium from a carbon concentrate (CC), a waste product of the aluminum industry, was considered. Ashing of CC made it possible to remove the main component - carbon and obtain ash, which is an oxide mineral-like compound, from which gallium was leached with solutions of inorganic acids and their mixtures. The maximum degree of leaching (98%) of gallium was achieved with 6 M HCl for ash after ashing the CC at 600 °C. It was shown that Purolite anion exchangers with highly basic tertiary and quaternary ammonium base groups recovered gallium(III) from 2 to 10 M HCl, where the sorption equilibrium was attained after 60 min. The maximum extraction was observed from 6 M HCl. Under optimal conditions, the maximum sorption capacities for gallium(III) were achieved for Purolite A300 (2.7 mmol g−1) and Purolite A500 (2.2 mmol g−1) sorbents. Gallium(III) was quantitatively (99%) eluted from the sorbents with distilled water. Sorption of gallium(III) and its subsequent desorption with water made it possible to separate it from the predominant amounts of transition metal ions: Fe(III), Ni(II), Co(II), Zn(II), V(V) and other cations: Al3+, Ca2+, Mg2+, Na+ and K+. The addition of sodium hydroxide to the concentration of 200 g L−1 resulted in the cementation of gallium on aluminum gallama (liquid gallium‑aluminum alloy). •A method for isolating gallium from carbon concentrate has been proposed.•The carbon concentrate was ashed at 600 °C.•Ga was leached from ash with hydrochloric acid solutions.•Ga was isolated from hydrochloric acid solutions by highly basic anion exchangers.•After elution with water, gallium was cemented onto aluminum gallama.