Physicochemical research of peculiarities of technogenic metallurgical wastes and mathematical optimization of ecologi-cally safe technology of their processing are of great practical importance for solving ecological problems of the region. The aim and the main direction of the research are...

In this article, maintaining the quality and commercial properties of mineral fertilizers during repeated transshipment and long-term transportation is one of the important issues. The purpose of the research work is to study the structure of granules of complex mixed fertilizers, as well as to find and develop methods for improving it at the production stage in order to improve the physical and mechanical properties of the finished product. In order to improve the granular structure of the mineral fertilizer, the static strength of the granules, the mass fraction of moisture, the chemical composition and structural shape of the granules were determined using an electron microscope. Using the X-ray microtomography method, experimental data on the internal structure of granules of complex mineral fertilizers were obtained and generalized for the first time, porosity, the nature of the distribution of pores and components of granules by volume were assessed. It has also been studied that the structure of granules and the nature of the pore distribution of fertilizers obtained according to different granulation schemes have fundamental differences, which is explained by the difference in the mechanisms of granule formation. It has been shown that when producing NP and NPS fertilizers using a reverse neutralization scheme, existing defects in the granule structure (cracks and pores) do not impair the physical and mechanical characteristics of the product, which makes it possible to recommend this scheme for use and thereby increase productivity by 20-25%.

An effective approach to maintaining uninterrupted coolant flow in heat supply systems—and thereby reducing energy consumption—is to prevent the formation of corrosion-scale deposits on the inner surfaces of metal pipes. This is typically achieved by performing anti-corrosion treatment on the coolant. However, the efficiency of this method depends on several factors, including pipe conditions, water flow rate, and water composition. To inhibit corrosion and scale formation on the internal surfaces of pipelines, specific inhibitors are used to create protective films on the metal surface. For strong adhesion of these films, preliminary chemical cleaning of the metal surface with low-concentration acid solutions is essential. This cleaning is usually performed in circulation mode for several hours. The activated surface enhances inhibitor adhesion, leading to the formation of films with improved protective properties. The quality of the anticorrosive films was evaluated using a JSM-6490LV scanning electron microscope equipped with INCAEnergy energy-dispersive microanalysis systems, HKL-Basic structural analysis, ContrAA-300 atomic adsorption spectrometer, and potentiostat IPC-Pro MF.

One of the pressing issues today is common salt purification from harmful impurities and production of salt for medical and household purposes. To obtain high-purity sodium chloride salt, it is necessary to develop more effective methods for purifying salt from impurities. The article discusses modern methods for purifying Suzak deposit common salt from harmful impurities. The main goal of the scientific work is to study the methods of purifying sodium chloride from impurities. The common salt raw material composition was studied. The content of impurities of Са2+, Мg2+ and SO42- ions and heavy metals Pb (II), Cu (II), Cd (II), As (V) was determined. The solubility in the systems NаСl-Nа2SO4-Нᡃ2O, NaCl-CaCl2-H2O and NаСl-MgCl2-H2O at a temperature of 100-110°C was studied. The effect of temperature and time on the common salt purification degree using active reagents was studied. It was found that the highest common salt purification degree from Са2+, Мg2+ and SO42- at 30 minutes and 90°C, respectively, is 99.8%, 99.9%, 99.93%. It was found that the use of a three-component mixture of Mg(OН)2:СаCО3:CaSO4 in a ratio of 1:4-5:6-7 for 20 minutes during purification allows purifying the NaCl solution from trace impurities of Pb(II), Cu(II), Cd(II), As(V) by 92.0-97.7% and obtaining 99.4% NaCI. To obtain high-purity salt, effective purification methods of salt from impurities are recommended, allowing to achieve a purification level of up to 99%.

Introduction: The article presents the results of chemical and physicochemical analysis of initial lithium-containing hydromineral raw materials and sorbent based on bentonite clay with titanium oxide addition. Methods: It is established that the mineral is montmorillonite group and kaolinite according to the results of the analysis of the microstructure and elemental composition of bentonitic clay of the Darbazinsky deposit. Brine is characterized by the change of lithium chloride content in the range of 403-1001 mg/l. Physical and mechanical characteristics of the obtained sorbents based on bentonite clay and titanium oxide additive are characterized by a high mechanical strength of 5.31 MPa, density of up to 2,6 g/cm³, and specific surface area of 1572 cm²/g. The technological parameters of sorption extraction of lithium chloride from lithium-containing hydromineral raw materials were optimized using the system analysis “STATISTICA” developed by StatSoft company. It is established that to increase the rate of lithium chloride extraction from brine, it is necessary to maintain the rate of brine flow within 8 l/min at maximum humidity of solution output up to 43g/m³ on the basis of the obtained volumetric graphical dependencies. Results: The microstructure of the used sorbents with titanium oxide addition up to 20% is characterized by the predominance of lithium chlorides, which are represented by heap-shaped, prismatic crystals. Conclusion: The maximum amount of lithium chloride in the form of clusters of light-white crystals of tabular shape on the surface of the sorbent is observed at increasing the content of titanium oxide up to 40%.