COMPARATIVE ANALYSIS OF PHYSICO-CHEMICAL METHODS FOR PROCESSING ALUMINUM WASTE

The relevance of the study is caused by the need to develop new methods for the disposal of metal waste. This direction, with the participation of various intensifying influences, refers to resource-saving, technological, minimizing the volume of capital costs for raw materials, production and subsequent sales. Purpose: to study physical and chemical methods for alkaline and acid processing of aluminum waste in the field of ultrasound, consider the mechanisms of these processes, compare kinetic characteristics, identify the pros and cons of the methods, and, based on a comparative analysis, conclude which of the methods is the most effective. Objects: samples of aluminum waste in the form of plates and shavings. Methods: volumetry, sonochemical synthesis, evaluation and analysis of the kinetic curves of the process at different temperatures, X-ray phase analysis. Results. The analysis of kinetic curves, rate constants of processes at different temperatures, and orders of chemical reactions has been carried out. The values ​​of the activation energies of the target chemical reactions and the characteristics of the kinetic regions of the processes were compared with each other. Despite the long induction period, the kinetic potential of acid processing of aluminum waste turned out to be 2 times higher than that of alkaline processing at temperatures of 313–323 K. Ultrasonic radiation did not significantly affect this characteristic, although it reduced the induction effect by 2 times. The mechanisms of the ongoing sonochemical processes in these methods turned out to be very similar to each other, no fundamental differences were observed. The products obtained during chemical processing in the form of hydrogen, hydroxide, chloride and aluminum orthophosphate are currently in high demand in the energy, chemical and silicate industries, as well as in medicine.