Abstract
Raman spectra have been measured for aqueous Al2(SO4)3 solutions from 25 to hydrothermal conditions at 184°C under steam saturation. The Raman spectrum at 184°C contained four polarized bands in the S–O stretching wavenumber range, which suggest that a new sulfato complex, where sulfate acts as a bridging ligand (possibly bidentate or tridentate), is formed in solution, in addition to a 1:1 aluminium(III) sulfato complex, where sulfate is monodentate, which is the only ion pair identified at room temperature. Under hydrothermal conditions, it was possible to observe the hydrolysis of aluminium(III) aqua ion by measuring the relative intensity of bands due to SO2−4 and HSO4−, according to the coupled equilibrium reaction [Al(OH2)6]3+ + SO42− ⇋ [Al(OH2)5OH]2+ + HSO4−. The precipitate in equilibrium with the solution at 184°C could be characterized as a hydronium alunite, (H3O)Al3(SO4)2(OH)6, by chemical analysis, X-ray diffraction, and Raman and infrared spectroscopy.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
