An Experimental Study of Phase Transformations of Aluminum Oxides in the Processes of Sub- and Supercritical Water Oxidation of Metallic Aluminum

• Published in: High temperature 2022-04, Vol.60 (2), p.177-181
• Main Authors: Gilmutdinov, I. I., Sandugei, N. S., Gilmutdinov, I. M., Kuznetsova, I. V., Kharlampidi, Kh. E., Sabirzyanov, A. N.
• Format: Article
• Language: English
• Subjects: Aluminum oxide; Atoms and Molecules in Strong Fields; Classical and Continuum Physics; Corundum; Industrial Chemistry/Chemical Engineering; Laser Matter Interaction; Materials Science; Oxidizing agents; Phase composition; Phase transitions; Physical Chemistry; Physics; Physics and Astronomy; Pressure effects; Reaction time; Supercritical water oxidation; Temperature effects; Thermophysical Properties of Materials; Transitional aluminas
• ISSN: 0018-151X; 1608-3156
• DOI: 10.1134/S0018151X22020183

In this work, samples of metallic aluminum are objects of sub- and supercritical water oxidation. Experimental studies have been carried out, and dependences of the effect of temperature, pressure, reaction time, and pH of the oxidizing agent on the phase composition of the oxidation products and their adsorption properties have been revealed. Experimental studies have been carried out in the temperature range of 275–380°C, reaction time from 3 to 12 h, and different water pH of 7–12. Maximum specific surface S = 120.2 m 2 /g samples obtained at temperature T = 380°C and reaction time τ = 3 h with pH 12. The phase composition of this sample included aluminum oxide γ-Al 2 O 3 (92.3 wt %) and corundum α-Al 2 O 3 (7.7 wt %).