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

Quantitative and Qualitative Analysis of Hydrogen Accumulation in Hydrogen-Storage Materials Using Hydrogen Extraction in an Inert Atmosphere

Currently, standard samples with high hydrogen concentrations that meet the requirements of hydrogen extraction in an inert atmosphere are not currently available on the market. This article describes the preparation of Ti-H standard samples and the calibration of RHEN602, a hydrogen analyzer, using LECO (LECO, Saint Joseph, MI, USA). Samples of technically pure titanium alloy were chosen as the material for sample production. The creation procedure includes five main steps: sample preparation (polishing to an average roughness of 0.04 μm using sandpaper), annealing, hydrogenation, maintenance in an inert gas atmosphere, and characterization of the samples. The absolute hydrogen concentration in the samples was determined by two methods: volumetric and mass change after the introduction of hydrogen. Furthermore, in-situ X-ray diffraction, temperature programmed desorption (TPD) analysis, and thermogravimetric analysis were used during measurements to investigate the phase transitions in the samples. As a result of this work, a series of calibration samples were prepared in a concentration range up to 4 wt % hydrogen, optimal parameters for measuring high concentrations of hydrogen. The calibration line was obtained and the calibration error was 10%