Preliminary electrochemical study to obtain α-alumina from aluminum scrap

Abstract

Alpha alumina is an aluminum oxide (a-Al₂0₃) and an advanced ceramic, thermodynamically stable with high hardness values, wear resistance and has high stability at high temperatures. This paper presents a preliminary electrochemical study to obtain α-alumina using different materials as working electrodes (silver, titanium, aluminum, tungsten and glassy carbon) and from aluminum scrap as raw material. In this study was possible to obtain an electrolyte with  Al³⁺ ions from scrap aluminum dissolved in a 2.8 M NaOH solution, as Al₂(SO₄)₃. Voltammetric results allowed observing the electroactivity response, limited by the reaction of hydrogen evolution in the different working electrodes, identifying some mainly reduction processes and oxidation in the aluminum electrode. Through of chronoamperometric study and aluminum electrode as working electrode, was achieved to obtain a deposit with a white hue and morphology ranging from spherical to irregular, indicating the presence of aluminum oxide, according to the literature. In contrast, in the electrodes of tungsten, titanium, glassy carbon and silver, no deposit was obtained.