Kompleksnoe Ispolzovanie Mineralnogo Syra = Complex use of mineral resources

Methods for purifying table salt from the Suzak deposit

A.A. Anarbayev, B.N. Kabylbekova, B.M. Smailov, G.M. Ormanova — Mon, 07 Apr 2025 00:00:00 +0000

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%.

Epoxy Resin Development for Anticorrosion Coatings

Wed, 09 Apr 2025 00:00:00 +0000

In this study, a high molecular weight epoxy resin (ELM-NG 900Z) based on diglycidyl ether of bisphenol A was cured with different types of hardeners to examine their impact on the physical and mechanical properties of the epoxy resin. The hardeners used were G-5022X70 (140-170 mg KOH/g), G-A0533 (310-350 mg KOH/g), and G-0930 (280-320 mg KOH/g). The results indicated that the hardener G-A0533 provided the best mechanical properties for the epoxy resin compared to other hardeners. Furthermore, various additives including silica fume, talc, barium sulfate, ferric oxide, and pigments were mixed with the epoxy resin in the presence of the hardener G-A0533 to enhance its mechanical properties. It was observed that the addition of 3% silica fume, 10% ferric oxide, and 3% inorganic pigments improved the mechanical properties, while the addition of 5% talc decreased most mechanical properties and only increased hardness. The incorporation of barium sulfate into the epoxy resin enhanced adhesion and flexural strength but decreased tensile strength and hardness. The inclusion of organic pigment had no significant effect on the mechanical properties of the epoxy resin. This enhancement in mechanical properties is attributed to the type of hardener used as well as the types and amounts of additives mixed with the epoxy resin.

Study of Steam Condensation on Vertical Finned Tubes

Thu, 10 Apr 2025 00:00:00 +0000

The article is devoted to the methodology of conducting and processing the results of an experimental study of the process of condensation of water vapour on vertical pipes with specially profiled fins of a heat exchanger. Based on the analysis of heat transfer during laminar condensation of water vapour in the form of a layer of flowing liquid both inside and on the outer surface of vertical pipes with a stationary steam flow, a laboratory installation was developed on which experimental studies were carried out. One of the ways to intensify heat transfer is to optimize the geometry of the heat exchange surface on the condensation side, which reduces the thermal resistance of the wall layers of the resulting condensate. This method is based on increasing the heat exchange area by using specially shaped fins on the surface of the heat exchanger tubes. As a result, an important scientific problem is being solved – disruption of the continuous flow of laminar condensate, which contributes to the direct contact of steam with the cooled surface of the pipe and increases heat transfer. The article describes the methodology of conducting experiments, describes the methods of processing the results obtained, as well as provides calculated data and graphical dependencies illustrating the experimental results.

Development of Hybrid Coatings for Anti-Corrosion Applications in Oil and Gas sector

Fri, 11 Apr 2025 00:00:00 +0000

The physical, and mechanical properties as well as chemical and corrosion resistance of hybrid coatings comprising polyurethane/acrylic hybrids (PUA/AC) and acrylic polymers (AK) were investigated. Polyurethane (PUA) was synthesized through polyaddition polymerization of isocyanates [Isophorone diisocyanate (IPDI) and hexamethylene diisocyanate (HDI)] with polyols (GP 2000 and GP 4000) at an NCO/OH ratio of 0.85 and a temperature of 100°C. The acrylic copolymer (AC), based on methyl methacrylate (MMA) and butyl methacrylate (BuMA), was produced via bulk polymerization with benzoyl peroxide as a catalyst. The acrylic copolymer (AK) was prepared by grafting xanthan gum with styrene in various ratios (XG: St = 1:1.6, 1:5, and 1:8 w/w%). The results revealed that hybrid coatings demonstrated optimal chemical and corrosion resistance when PUA/AC hybrids were combined with AK. Enhancing both mechanical properties and corrosion resistance was achieved by integrating PUA/AC-10 with AK containing 8% styrene, resulting in superior anticorrosion performance including chemical and solvent resistances for the hybrid coating.

Utilization of Natural Silicate Rocks to Reduce the Carbon Footprint in the Cement Industry

M.I. Iskandarova, F.B. Atabaev, A.Sh. Khadzhiev — Thu, 17 Apr 2025 00:00:00 +0000

Portland cement production is associated with high energy consumption and CO₂ emissions, highlighting the need for alternative raw materials to improve environmental sustainability. Research findings indicate that porphyrite, a natural silicate rock, exhibits pozzolanic and hydraulic activity, making it a promising additive in composite cement production. In this study, the physicochemical properties and hydration processes of porphyrite-modified Portland cement were analyzed using X-ray diffraction (XRD), differential thermal analysis (DSC), and Fourier-transform infrared spectroscopy (FTIR). The compressive strength and setting time of cement samples were tested according to GOST 30744-2001 and GOST 310-91 standards. The results showed that porphyrite addition slightly slowed the hydration process, reducing C₃S content while promoting the formation of calcium hydroxide (Ca(OH)₂). Cement containing 20% porphyrite met the 32.5N strength class requirements and demonstrated stable mechanical properties. Water absorption tests confirmed a gradual hydration process, with no sudden crystallohydrate formation observed. This study confirms that porphyrite is an effective mineral additive, contributing to cement durability, reduced clinker consumption, and lower energy demand. Future research should focus on the long-term stability of porphyrite-based cement using advanced thermal analysis techniques.

Effect of Rice Straw on the Mechanical and Biodegradability Properties of the Poly (Polyethylene-G-Acrylic Acid)

Mon, 21 Apr 2025 00:00:00 +0000

A polyethylene/acrylic copolymer was synthesized using a grafting technique with benzoyl peroxide as a catalyst and xylene as a solvent. Acrylic acid (AA) was grafted onto polyethylene (PE) in a 1:5 ratio. The resulting grafted copolymer, characterized by FTIR, was blended with rice straw at varying percentages of 3%, 5%, and 7% to produce biodegradable films. The properties of these films in water were evaluated through analyses of viscosity, tensile strength, elongation at break, water contact angle, and solubility. Incorporating rice straw enhanced the grafted copolymer's biodegradability, resulting in increased viscosity, tensile strength, and elongation at break of the films, while reducing the water contact angle and solubility. However, incorporating 7% rice straw in the grafted copolymer-based on PE (1.0%) and AA (5.0%) resulted in increases in viscosity, tensile strength, and elongation at break by 29.5%, 46.1%, and 9.6%, respectively, while reducing the contact angle and biodegradability solubility time at 45°C by 25.8%.