INDUSTRIAL TECHNOLOGY AND ENGINEERING

INTENSIFICATION OF A BRINE PURIFICATION PROCESS IN THE OF SODA ASH PRODUCTION BY THE INTRODUCTION OF FLOCCULANTS

M.Z. Yeskendirov — 2022-06-29

This article considers the results of studying the purification of the sodium chloride brine used for manufacturing soda ash by the ammonia method. The purpose of the study was to develop a purification method involving coagulation and flocculation processes using polyacrylamide flocculants in the presence of surface-active substances as crystallization modifiers. A complex technology for purification of the brine from magnesium and calcium compounds and sulfate ions is proposed, which includes three stages for sodium chloride solutions with a high Mg²⁺content and two stages for the brines with a low Mg²⁺content. The article contains the results of experiments to investigate the effect of the concentration of anionic polyacrylamide flocculants on the height of the clarified layer when removal of calcium and magnesium ions. The best result was achieved at using an anionic polyacrylamide flocculant Flopam AN 934 PWG at its concentration of 0.004% wt. The introduction of sodium tripolyphosphate improves the flocculating effect of the anionic polyacrylamide flocculant and increases the suspension clarification rate. The best indicators were obtained at 0.05% wt of sodium tripolyphosphate. With the simultaneous use of a cationic polyacrylamide additive Superfloc C-498 (4·10^–4% wt.) and sodium tripolyphosphate (0.05% wt.), the concentration of sulfate ions in the purified brine was 0.016 g/l; this corresponds to the purification efficiency of 99.75%. It has also been established that the use of surface-active substances in combination with polyacryamide flocculants makes it possible not only to increase the suspension clarification rate, but also to obtain the cleaner brine.

UTILIZATION OF POLYETHYLENE TEREPHTHALATE IN ORDER TO OBTAIN POLYMERIC CORONA ELECTRETS

A.Sh. Kydyraliyeva — 2022-06-29

The possibility of recycling recycled polyethylene terephthalate (plastic) in order to obtain polymer corona electrets and compositions, sealing materials, compositions for corrosion protection was explored in this article.

Work objective is to study the effect of a dispersed filler - wollastonite and a stabilizing additive - technical gossypol, as well as savilen on the electret properties of a composite based on waste plastic materials - polyethylene terephthalate (PET). Technical gossypol, wollastonite of the Verkhnebadam deposit (Kazakhstan, Turkestan region), savilene - a copolymer of ethylene with vinyl acetate and a finished composite: mineral filler - wollastonite; sevilen; technical gossypol; PET - the rest were the objects of study. It has been established that the introduction of fillers into the composition of a PET-based composite leads to an increase in its density and degree of crystallinity in the composition of the composite and, as a result, to a decrease in its moisture permeability, which leads to a decrease in conductivity, and hence, an increase in the stability of the electret state of composite films. Changes in the surface structure of polyethylene terephthalate and its compositions with the above components during electretization were established using microscopy and infrared spectroscopy.

Additives of the above components to the composition of a composite based on recycled polyethylene terephthalate affect the electretization process, the effect of the interaction of various fillers can significantly change the stability of composite electrets, which seems promising for using the results obtained in the chemical and petrochemical industries.

PROBLEMS AND PROSPECTS OF MECHANICAL ENGINEERING DEVELOPMENT IN KAZAKHSTAN

I.S. Polezhayeva — 2022-06-29

Mechanical engineering is the most important branch of the economy of any industrially developed state. By producing all kinds of equipment, machines, machines, devices, as well as goods for the population, mechanical engineering ensures the stability of the activities of the agro-industrial complex, the energy and metallurgical sectors, transport and other key sectors of the economy. Sustainable development and reliable functioning of mechanical engineering largely determine the energy and material intensity of the economy, labor productivity, the level of environmental safety of industrial production and, ultimately, the economic security of the country. This article reviewed the development of mechanical engineering in Kazakhstan. The authors considered the dynamics of production of machine-building products, highlighted the main sub-sectors of development, determined the role of machine-building products in foreign economic flows. The article pays special attention to identifying the most acute problems in the development of the industry. To date, there are systemic problems in the Kazakh machine-building industry related to the insufficient level of investment attractiveness of the industry, the low level of competitiveness of products in the domestic and foreign markets, and a shortage of qualified personnel. Today, the industry needs further effective and high-quality development. Kazakhstan faces common tasks to preserve and develop the potential of mechanical engineering and import substitution of the main mechanical engineering products.

APPLICATION OF THE COMPUTATIONAL ALGORITHM OF THE MATRIX SWEEP METHOD

P.A. Kozhabekova — 2022-06-29

The solution of inverse problems of thermal conductivity with a high-precision scheme is carried out by the method of approximate selection in the given article.

However, they try to use internal inverse problems of thermal conductivity to simplify calculations, which leads them to specific analytical expressions that are independent of the thermal effect, temperature field, and geometry of the sample. The solution of inverse problems of thermal conductivity with a high-precision scheme is carried out by the method of approximate selection.

The high-precision method is considered with the crank-Nicholson type difference scheme in this article. The crank-Nicholson type scheme is a parabolic differential equation of finite difference.

In particular, the advantage of the difference scheme is that the solution in the upper time layer is obtained immediately according to the values of the grid function in the lower time layer and it is without the solution of the system of linear algebraic equations (Satz), and also in it the solution becomes known (at k = 0, the values of the grid function are formed from the initial situation). But the same scheme has a significant disadvantage, since it is conditionally stable. On the other hand, the fuzzy difference scheme leads to the need to solve the SATs of a system of linear algebraic equations, but this scheme is absolutely stable.

The solution of the inverse problem of thermal conductivity with a high-precision circuit is defined as the limit of the solution group.For example, a well-known calculation algorithm of the Matrix method is used to solve a three-point boundary problem, the parameters of which satisfy the stability condition. Since there are inverse matrices, the necessary conditions for the stability of the Matrix method are met.

PHYSICO-CHEMICAL CHARACTERISTICS AND METHODS OF PURIFICATION OF SODIUM CHLORIDE

S.P. Nazarbekova — 2022-06-29

Sodium chloride, called table salt, plays a huge role in maintaining life. The human body contains about 0.25% sodium chloride (in the form of ions). A person needs 5-10 g of table salt daily, since the salt balance is related to the body's water balance. Sodium chloride retains water in tissues, the necessary amount of it in the body creates a favorable environment for the action of protolytic enzymes of gastric juice, affect the electrical conductivity of cell membranes, etc. In addition, especially pure sodium chloride is used to prepare 0.9% isotonic solution for intravenous infusion, 20% solution to stop bleeding, as well as to obtain drugs "Hemodesis", "Rehydron" and for other purposes in medicine. Therefore, obtaining especially pure sodium chloride for the needs of the pharmacopoeia is an important task.

This article provides information about the physico-chemical characteristics and various methods of purification of sodium chloride for its further use in medicine.

INSTALLATION FOR DRYING RAW MATERIALS OF VEGETABLE ORIGIN

D.R. Totrtbayeva — 2022-06-29

The production of fruits and berries in the Republic of Kazakhstan is almost two times lower than the global consumption norms. The actual consumption of these crops in different years varied depending on the ratio of exports and imports, but it was always below the consumption norms. In most cases, this can be explained by their complexity in the technology of storing the resulting crop. At present, in connection with the transition to small-scale farms and agricultural firms, it becomes economically feasible for commodity producers to store and process fruits and vegetables directly on their farms. This makes it possible to solve many issues of logistics and management, to carry out the processing of products and their trade in the most favorable conditions, the formation of a certain conjuncture and pricing policy. The drying in the process of harvesting raw materials is of great importance, and the observance of proper storage conditions for dried products. However, the installation that is used for drying plants in the existing production structures does not currently meet the necessary requirements. The introduction of new technologies and techniques is the most important way to increase the efficiency of drying units and improve the quality of the processed material. The creation of a plant for drying stem agricultural products and the rationale for its main parameters is described in this article. The purpose of creating such a device and substantiating its parameters was that during natural drying, the products dry unevenly, as a result of which some parts of the product dry out, and some parts rot without completely drying out.

INDICATORS OF CORROSION RESISTANCE OF EQUIPMENT IN VARIOUS AGGRESSIVE ENVIRONMENTS

N.A. Vysotskaya — 2022-06-29

The aggressiveness of the coolant composition is caused by various carbon dioxide -based components, such as CO₂, H₂CO₃, HCO₃^-, CO₃^2-, OH^-, H⁺, Na⁺, K⁺, Mg²⁺, Ca²⁺, Cl^-, SO₄^2-, as well as a soluble oxygen molecule and slightly soluble hydrogen sulphide. Such a composition of the coolant, taking into account the indicated ions that are in a dissolved state, it can be said with confidence, is capable of forming and depositing a corrosive composition in the form of scale on the inner surface of pipelines that prevents the free passage of the coolant. Due to the occurrence of electrochemical processes, OH^-, Mg²⁺, Ca²⁺, Fe²⁺ products formed near the metal surface of the pipeline are capable of forming and depositing a significant amount of corrosive carbonate sediment on the inner surface of the pipe, causing significant corrosion of the steel surface of the pipeline. Carbonate sediment significantly complicates the passage of the coolant through pipes in heat supply systems.

RESEARCH OF PHOTOELECTROCHEMICAL PROPERTIES OF CuBi2O4 BASED PHOTOCATHODES AND THEIR MODIFICATION BY SILVER IONS ON CONDUCTIVE GLASSES

A.A. Seitmagzimov — 2022-06-29

The article presents the results of the study of photo electrochemical properties of copper-containing photocathodes on conductive glasses by aqueous solutions pyrolysis and electrochemical method. All electrodes showed absorption in the entire range of the visible spectrum, starting from 330 nm and above, at that silver alloying of copper bismuthate results in decrease in optical density of the electrodes, which is accompanied by a large value of current indicators. It is shown that cathodes based on copper oxide have minimal photocurrents, whereas triple copper oxide based on copper bismuthate shows much better indicators at aqueous solutions electrolysis. This may be due to intensification of main carriers tunneling process at concentration points of silver ion centers in an array of copper bismuthate film. This is due to additional current component in general voltage–ampere characteristic of the electrode, i.e. the current is ultimately higher for the sample with silver ions than without it. Almost fivefold increase in photocurrents on the electrodes of copper bismuthate doped with silver ions in the sacrificial electrolyte has been achieved.