KINETICS OF THE REGENERATION OF SPENT СHROMIUM-CONTAINING SOLUTIONS

Abstract

Research into the kinetics of processes associated with the regeneration of spent chromium-containing solutions primarily aims to determine such basic parameters, as the order and rate constants of the reactions involved, their activation energies and transference numbers. All these parameters determine the efficiency of the regeneration process and its power consumption values. In addition, knowledge of these dependencies is essential for the selection of optimal operating modes of a device for regenerating spent chromium-containing solutions, as well as for the development of mathematical models and engineering calculation methods describing such processes. On the basis of experimental data, a functional relationship between changes in the values of electric current intensity and transference numbers has been established. The optical density of samples was measured using a photoelectric concentration colorimeter KFK-2-UHL 4.2. The voltage and current intensity values were controlled and regulated using a power supply unit Mastech HY3005-2. It is shown that an increase in the intensity of electric current leads to a decrease in the mobility of chromium ions. This occurs because the gas is absorbed by the solution, which prevents the passage of electric cur-rent. In addition, an increase in the current intensity results in the deposition of chromium on the electrode. Optimal dependencies between the key kinetic characteristics and parameters of the re-generation process are provided. Diagrams are presented for calculating optimal parameters of the process and corresponding power consumption values, which can be helpful in carrying out the re-generation of spent chromium-containing solutions with a high efficiency.