It is generally accepted that the color and performance characteristics of liquid thermal insulation coatings are affected by the combined effect of various climatic factors such as solar radiation, temperature fluctuations, moisture, precipitation and others. This work presents the results of a scientific study of the full-scale exposure of coatings with regard to climatic ageing. Methods have been carried out, such as: spectrophotometry and direct scanning; determining adhesion, determining the adhesion strength of facing and protective coatings; and thermal conductivity and thermal resistance. As the results of the research work have shown, only in situ climatic tests, accompanied by the obligatory recording of the aggressive factors affecting the coating, make it possible to assess changes in the properties of epoxy coatings in full-scale conditions and, consequently, their climatic resistance by the methods of spectrophotometry and direct scanning. The ageing of polymer composites is known to be accompanied by a change not only in elasticity but also in color. Of the epoxy coatings tested, Etal-45M showed the greatest color variation during the in situ climate test. The most decorative resistant coatings are obtained using epoxy resin ED-20 + modified epoxy resin Etal-1440N.
This article examined the characteristics of zeolites from the Chankanai and Daubabinsk deposits. In the field of water treatment, the purpose of investigating natural zeolite from the Chankanai and Daubabinsk deposits as a sorbent presents new opportunities and prospects, as this raw material is little studied. The effectiveness of the sorbents was assessed based on the results of the water specifications according to the following criteria: methods for determining the total hardness of water; methods for measuring the mass concentration of total iron in water; methods for the determination of chloride in water; methods for the determination of nitrogen-containing substances in water; methods for determining the dry residue content of water; methods for determining the sulphate content of water; on hygiene requirements and water quality control. Zeolite modifications were aimed at improving their adsorption properties, increasing the efficiency of pollutant removal and developing optimal methods of using zeolites in water filtration. Modified zeolite from the Chankanai and Daubabinsk deposits showed high efficiency as a filter. When it was used to treat natural water, which normally contains high hardness and alkalinity, the best results were achieved with zeolite from the Chankanai deposit. In terms of Fe+ and Cl content, the best results were achieved using zeolite from the Daubabinsk deposit.
This study aimed to identify the composition of ceramic mass for the manufacture of bricks with improved properties based on local loam using diatomite and bentonite clay. For the experiments, loam from the Almaty deposit (Kazakhstan) was applied as the primary product, and used for the production of ceramic bricks with grades of 75 and 100. Diatomite from the Zhalpak and Utesai deposits and highly plastic bentonite clay from the Darbazin deposit (Kazakhstan) were used as additives. An analysis of the properties of the burned products demonstrated that supplementation with diatomite and bentonite in the loam lowers the average density and increases the compressive strength of samples burned at 1000 and 1100 °C. Herewith, the optimal amount of diatomite and bentonite clay to add is 15%, with a fractional composition of 0.315–0.16 mm and less than 1 mm, respectively. It was established that the optimal additions of diatomite and bentonite clay to loam make it possible to obtain after burning at 1170 °C samples of ceramic products corresponding to the 2nd class in terms of the average density and compressive strength grades M 400 and M 500.
The article provides an overview of studies on the causes of the formation of hydrogen sulfide in anaerobic conditions of urban sewage systems and methods for neutralizing toxic reagent sulfur-containing compounds. It is noted that the presence of sulfur compounds and organic components in sewage flow leads to the formation and release of hydrogen sulfide into the atmosphere of settlements. Three main categories of methods for purifying sewage wastewater from hydrogen sulfide are presented. In this work, a complex alumina-ferrous coagulant has been developed from Kazakh raw materials. Based on natural ferruginous diatomite and middlings of sintered alumina, a complex alumina-ferrous coagulant has been synthesized, which is effective in purifying wastewater from hydrogen sulfide, accelerating the processes of sedimentation and clarification of sewage slurries. Experimental results also show that with the supply of increased amounts of coagulant, oil and oil films disappear from the surface of the cylinder, an almost complete purification of effluents from hydrogen sulfide compounds occurs, and the color of the liquid part is greatly reduced. In addition, the advantage of the developed reagent is that it is presented in the form of fine powder and can be easily dosed and added to a canalization pump station to interact with diluted hydrogen sulfide and be transported to sewage fields. Compared to other proposed methods in previous works, the reagent is suitable to be used directly in sewage systems such as sewage waters treatment plants and collectors to prevent hydrogen sulfide emission into the air atmosphere of populated areas, as well as at city sewage water treatment stations after air tanks and before secondary clarifiers to obtain better purified water suitable for watering agricultural plants.
The purpose of this work was to investigate the effect of the burning environment on the properties and phase composition of clinker-based ceramic specimens made from loam with diatomite and bentonite clay in order to develop technological parameters for the manufacture of clinker products. The main raw material used for the experiments was local fusible loam from the Almaty deposit, which is the basis for the production of 75 and 100 grade ceramic bricks. Diatomite from Utesai deposit (Aktobe region) and highly plastic bentonite clay from Darbazin deposit (Turkestan region) were used as additives. Loam and bentonite clay were applied after grinding and sieving through a 1 mm sieve. Diatomite was applied after grinding and milling until it had completely passed through a 0.315 mm sieve. The raw materials are mixed after dosing, and then water is added in the amount required until a pliable mass is obtained. To investigate the properties of the products, standard cylinder samples were prepared with a diameter of 50 mm and a height of 50 mm. The cylinder samples were pressed on a hydraulic press at a pressure of 2–4 kN. The samples were dried in a desiccator at 95–100 °C for 2 h. After drying, the products were burning in a muffle kiln. The analysis of the properties of the burned products showed that the optimum ratio in the ceramic mixture of loam and diatomite to loam and bentonite clay is 85%:15%. After burning in a slightly oxidising environment at 1170 °C, the ceramic specimens correspond to Class 2 for the medium-density and compressive strength grades M 400 and M 500 (GOST 530-2012 (Government standard). X-ray diffractometric analysis showed that the products contain augite, quartz and anorthite as crystalline phases, with the former predominating. After burning in a reducing atmosphere, at 1170 °C, the properties of the samples have higher values compared to the samples burning in a weakly oxidising atmosphere. The resulting properties, according to the regulations, are characteristic of clinker bricks (DIN V 105-1 (technical requirements for clinker façade bricks). After burning in a reducing environment, the phase composition of the products changes qualitatively; in addition to augite and quartz, albite, diopside, orthoclase and haematite are present in the samples.
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