Gallium extraction by microemulsions

• Published in: Talanta (Oxford) Vol. 56; no. 6; pp. 1089 - 1097
• Main Authors: de Castro Dantas, T.N, de Lucena Neto, M.H, Dantas Neto, A.A
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 08.04.2002; Oxford Elsevier
• Subjects: Aluminum; Applied sciences; Chemistry; Exact sciences and technology; Extraction; Gallium; Inorganic chemistry and origins of life; Kinetics and mechanism of reactions; Microemulsion; Other industrial wastes. Sewage sludge; Pollution; Reextraction; Selectivity; Wastes; Gallium; Extraction; Selectivity; Microemulsion; Aluminum; Reextraction; Industrial waste; Liquid liquid extraction; Waste reuse; Metallurgical industry; Aluminium; Hydrometallurgy
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/S0039-9140(01)00643-9

In this work, the use of microemulsion in the extraction of gallium, with Bayer process, has been studied. The studied microemulsion systems were: systems I and II, with saponified coconut oil (SCO) and 4-ethyl,1-methyl,7-octyl,8-hydroxyquinoleine (Kelex-100) as extractants. The extraction essays by microemulsion were carried out by applying an experimental planning method whose microemulsion points were prepared within an experimental domain favorable to the extraction. Gallium and aluminum extraction percentages, in each point, were evaluated via a statistical treatment of the data, with the use of variance analysis and mathematical models. In system I (SCO), percentages of extraction of 85.5% for gallium and 35.4% for aluminum were achieved; in system II (Kelex-100), the yields were 100% for gallium and 99.9% for aluminum. The reextraction study with sulfuric acid presented the same behavior for both systems, with efficiency depending upon the concentration of the acid, and allowing for a selective reextraction of gallium and aluminum.