Studying the Mechanism of the Low-Temperature Oxidation of Microsized Aluminum Powder by Water

摘要

The mechanism of the oxidation of disperse aluminum (powder of ASD-4 grade) by liquid water was studied including the use of different process activation methods (thermal, ultrasonic, and chemical in the presence of small CaO amounts). For this purpose, the complex study of the aluminum oxidation process was performed at its different stages by analyzing the kinetic dependences of the hydrogen formation rate and the reaction medium pH change and using the instrumental methods of scanning electron microscopy and X-ray diffraction analysis. It has been demonstrated that the shape of kinetic hydrogen release curves, the oxidation process completeness, and the structure of formed hydroxides are interrelated. An essential role is played by the mass transfer of formed solid oxidation products from the surface of particles to the crystallization nuclei of aluminum hydroxide and the localization of crystallization areas. This work is topical because of the broad interest in the use of metallic aluminum as an energy-accumulating substance.