Separation of GaCl(3) from AlCl(3) by Solid–Liquid Extraction and Stripping Using Anhydrous n-Dodecane and NaCl

[Image: see text] Separation of GaCl(3) from other associating chloride compounds (e.g. AlCl(3), SbCl(3), and InCl(3)) is generally achieved by hydrometallurgical processes. In this study, we explore the separation of GaCl(3) from these compounds on the basis of the exceptionally high solubility of GaCl(3) in hydrocarbon solvents. We found that GaCl(3) can be efficiently extracted by anhydrous n-dodecane from a solid mixture of GaCl(3) and AlCl(3); on the contrary, SbCl(3) and InCl(3) significantly reduce the extraction of GaCl(3). On the basis of Lewis acidity theory and study of the Raman spectra, it is shown that formation of the ionic compound [SbCl(2)][GaCl(4)] is responsible for the reduced GaCl(3) extraction. Formation of [InCl(2)][GaCl(4)] is also likely, but further study is needed to support the existence of this compound. Further making use of the strong Lewis acidity of GaCl(3), GaCl(3) can be efficiently stripped from the loaded n-dodecane phase by solid NaCl through formation of NaGaCl(4). The extraction of GaCl(3) by n-dodecane, in combination with its stripping by NaCl, is a solvometallurgical process that is essentially different from the hydrometallurgical processes for the separation of GaCl(3) and AlCl(3).