Volume 59, Nº 6 (2025)

The previously developed resource efficient technological scheme of the hydrometallurgical process of metal separation from leaching solutions of lithium-iron-phosphate batteries is optimized. The approach used in this work is based on integrating the method of liquid pseudomembranes and hydrophobic deep eutectic solvents into the process scheme, combining environmental safety (biodegradability, low toxicity) with high efficiency. A step-by-step approach to optimizing the technological scheme is presented in order to reduce the number of devices, the degree of concentration, the efficiency of extraction, and the purity of the final products. The liquid pseudomembrane method is shown to allow reducing the number of device units from 10 to 8 as compared to the countercurrent scheme. A significant concentration of iron(III) ions by 25 times and copper(II) and aluminum(III) by 5 times in the re-extract phase is achieved when the purity of the products reached 100% (Cu), 99.8% (Fe), 99.8% (Al), and 99.5% (Li). As a result of, an optimized closed-loop scheme is proposed. The proposed methodology demonstrates that the combination of the LPM method and "green" solvents opens the way to resource efficient and environmentally balanced hydrometallurgy.

The specific energy dissipation rate and the micromixing quality (using the iodide-iodate technique) in a microreactor with coaxial chambers and counter-current intensively swirling flows (MRISF-CC-2) with various flow feed methods in a wide range of flow rates are studied. The dependence of the specific energy dissipation rate on the costs is found, as well as the dependence of the micromixing quality (the so-called segregation index) on the specific energy dissipation rate for three methods of feeding solutions to the device. The highest values of the specific energy dissipation rate are observed when feeding to the tangential nozzle of the inner chamber and the axial nozzle, values comparable to them are observed when feeding to the tangential nozzle of the outer chamber and the axial nozzle, and slightly lower values are observed when feeding to the tangential nozzles of the outer and inner chambers. A comparison of the segregation index with three other types of microreactors showed that, in general, all three methods of feeding into MRISF-CC-2 provide significantly higher micromixing quality. The micromixing indicators were slightly better in the MRISF-CC-2 microreactor as compared to the MRISF-CC-1 (with opposing chambers and counter-current intensively swirling flows). The presence of three high-intensity mixing zones and two intensive mixing zones in the microreactors with counter-current intensively swirling flows in MRISF-CC-1 and MRISF-CC-2 opens up wide possibilities for using these devices for multi-stage synthesis of nanoscale and submicron particles of inorganic materials, including composite materials.

Studying the patterns of interaction of ionic liquids with elemental sulfur is of particular practical interest since the S₈ ring-opening is the key stage in many chemical and technological processes. However, it involves significant energy costs. In this work, by the example of 1,3-dimethylimidazolium dimethylphosphate, the peculiarities of the reaction between dimethylphosphate-containing ionic liquids and elemental sulfur in organic solvents, leading to the opening of the sulfur ring at room temperature, are considered.

An approach to constructing observation systems for the state space of a reacting mixture is proposed. The observation system consists of subsystems of observing oscillators of the self-oscillatory type for the phase subspaces of the system of kinetic equations of the observed groups of substances of the reacting mixture. Geometrically, the approach is based on the scheme of synthesis of limit cycles in the observation phase space. With this approach, the output amplitudes of the observing self-oscillatory processes established in the observation system mean stabilization of the concentrations of the observed reagents in the ranges of their admissible values. Some mathematical aspects of the approach are considered. The results of the article are illustrated by numerical simulation of the dynamics of stabilization of the amount of matter and the phase dynamics of the observation system associated with it.

The setup for water treatment by plasma discharge in the cavitation field is improved. The new reactor configuration allows for treatment of water with increased electrical conductivity and mineralization (up to 5 g/l). This is achieved by increasing the cavitation area of the reactor by creating an idle area, which plays the role of additional resistance and reduces the leakage current resulting from ionic conductivity under increased mineralization. The use of the new reactor design significantly expands the scope of the potential practical application of this setup. Increased total mineralization usually characterizes water used in agriculture for watering plants and soaking seeds. During the work, the setup was also tested under the conditions of an aeroopic system for germinating Mamluk spring barley seeds. It is determined that the use of water treated with plasma discharge increases the content of vitamin C by 29% and total nitrogen and phosphorus by 25% and 13%, respectively.