Engineering Commons^™

Rotary Furnace Lining To Reduce Thermal Stress, Zamira Mukhamedbaeva, Erkin Kurbanov, Abduvali Mukhamedbaev

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of the study is to reduce the thermal stresses of the lining in the areas adjacent to the flare sintering zone of rotary kilns intended for the production of cement clinker. It is proposed to use a lining made of parallel rows of alternating chamotte and chromium-magnesite refractory products to reduce thermal stresses in the areas adjacent to the flare sintering zone by up to 20%, increase the service life of the lining by 1.1-1.2 times as a result of equalizing thermal stresses in the areas of the sintering zone. Optimization of the initial raw material mixture, in …

Computer Simulation Of Particle Velocity In A Cyclone, Askar Artikov, Botir Usmonov, Dilshod Karabaev, Anvar Ulmasbaev, Lola Akabirova

CHEMISTRY AND CHEMICAL ENGINEERING

The article sets the goal of determining and calculating the speed of accelerated movement of particles in the gas-dust flow of an air cyclone, depending on the size of the cyclone, the physical properties of the particle and the gas-dust flow. A method for constructing a computer model of the motion of a particle in a roaring gas-dust flow of a cyclone is presented. The sequence of formalization of the computer model of the process of sedimentation of particles of a gas-dust flow of a cyclone unit is based on the theoretical foundations of aerodynamics and touches on the most …

Anti-Corrosion Protection Of Metal Parts Of Transportation Equipment With A Polymer Coating Based On Epoxiurethane, Aida Barkhanadjyan, Ravshan Khakimov, Botir Ibragimov, Oybek Vafayev, Dmitriy Ayrapetov

CHEMISTRY AND CHEMICAL ENGINEERING

Automotive vehicles are constantly exposed to corrosion processes, and the durability of metal parts depends on the intensity of corrosion. The loss of metals from corrosion is 8-10% of the initial metal mass. In total, losses from corrosion are 4-6% of national income in many countries. This indicates the need for research and the importance of scientific and technical work in this area. This can be achieved by developing a technology for producing anticorrosive compounds and applying them as protective coatings. The anticorrosive protection of a coating synthesized on the basis of local raw materials - epoxyurethane with an additive …

Synthesis And Research Of Silicon-Containing Phthalocyanine, Dilmurod Shukurov, Hayit Turayev, Abdulakhat Djalilov, Masud Karimov

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of this study is to synthesize, and study a new form of dye based on phthalocyanine, a silicon-containing phthalocyanine pigment used as a dye for dye-sensitive solar cells, which are currently third generation solar cells as one of the energy source alternatives. To achieve this goal, a silicon-containing phthalocyanine pigment containing urea, phthalic anhydride and sodium fluorosilicate was synthesized and studied. Based on the results of IR spectroscopy, the reaction of pigment formation is proposed and the data of scanning electron microscopy is presented. Its differential thermal analysis, photodynamic analysis and its relationship with inorganic and organic solvents …

Development Of The Composition Of A Composite Material Based On Thermoreactive Binder Ed-20, Umida Ziyamukhamedova, Gavhar Miradullayeva, Erkin Rakhmatov, Jasur Nafasov, Mavtuna Inogamova

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of the study is to determine the effect of the type of structural modifier and filler on the structure formation and technological properties of potting composite polymeric materials (HCPM) and protective coatings for sheet and complex-configuration technological equipment, taking into account their rheological properties. Compositions of composite polymer materials based on a thermosetting binder of epoxy-diane resin ED-20 filled with a mineral filler - kaolin modified with gassipol resin (GS) - were developed using Newton's interpolation formula and the Lagrange method. The optimal amount of gossypol resin determined in the composition of the composite – in the amount …

Effect Of Talc On The Properties Of A Compound Based On Ethylene-Propylene Copolymer, Ikromjon Usmanov, Farrukh Kurbanbekov, Bobir Aykhodjaev, Ravshan Adilov

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of the research is to study the possibility of replacing Korean-made talc with inexpensive talc from an Afghan deposit, processed in Uzbekistan and used for the production of polypropylene compounds. In the future, these compounds are used for the manufacture of plastic car parts. A block copolymer produced by Uz Kor Gaz Chemical was chosen as a binder. For this, the influence of the content and type of talc on the properties of a compound based on an ethylene-propylene copolymer was studied.

The properties of the obtained compounds checked using ISO standards. The fractional composition of the studied …

Influence Of Sulfur Modification On The Properties Of Sulfur Concrete, Zhavkhar Khayitova, Khasan Beknazarov, Hayit Turaev, Abdulakhat Jalilov

CHEMISTRY AND CHEMICAL ENGINEERING

The purpose of this study is the synthesis and study of modified sulfur concrete for use in industrial construction. To achieve this goal, sulfur concrete based on gossypol resin and pyrolysis distillate was modified and studied. The strength properties of sulfur-based concrete obtained from sulfur modified with gossypol resin and pyrolysis distillate were investigated. For the addition to sulfur concrete, industrial waste was used as a finely dispersed filler - fly ash from the Angren TPP and phosphogypsum generated at Ammophos-Maxam JSC. It was found that the best strength results correspond to sulfur-based concrete modified with gossypol resin using an …

Physical And Chemical Studies Of Overroof Rocks Of Clay Shales Of The Dzherdanak Deposit, Mastura Aripova, Ivan Levitskiy, Khabiba Khamidova, Odelbek Ammanov

CHEMISTRY AND CHEMICAL ENGINEERING

The purpose of this study is study of the physical and chemical properties of the overburden of the Dzherdanak deposit. The chemical and mineralogical composition of the overburden of the Djerdanak deposit has been studied by the methods of X-ray and thermography, electron microscopy and infrared spectroscopy. The main phases are quartz, kaolinite and muscovite. The study of the fine structure of the rock under an electron microscope showed the homogeneity of the rock with pronounced uniform inclusions, which is preserved even after firing. Changes in the rock after firing at 1050 °C have been determined. The formation of mullite …

On The Possibility Of Obtaining Effective Phosphoric Fertilizers As A Result Of Interaction Of Phosphorite-Containing Waste With Activated Glauconite Sands, Nargisa Takhirova, Fazlidin Khudoyberdiev, Shahlo Daminova

CHEMISTRY AND CHEMICAL ENGINEERING

These studies are devoted to the study of the chemical properties obtained as a result of chemical activation of glauconite and further neutralization of activated glauconite by waste products of phosphorite concentrates. Based on the results of X-ray structural studies of the obtained products, it is possible to obtain granular complex fertilizers after adding phosphorites to the system. Activation with mineral acids (nitric or sulfuric) should be carried out to accelerate the transformation of minerals from glauconite sands into an easily digestible form. Since the obtained compounds form an acidic environment, it is necessary to neutralize them. The neutralization process …

Study Of Sorption Of Rhenium Ions On Solid Extragents, Otabek Pardaev, Dildora Ilkhomjonkizi Khakimboeva, Shahlo Daminova, Ulugbek Sharafutdinov, Sharipov Khasan Turabovich

CHEMISTRY AND CHEMICAL ENGINEERING

In this work, the aim is to study the possibility of extracting rhenium from sulfuric acid solutions by sorption of impregnated sorbents based on polystyrene-divinylbenzene (MN202) and an organic reagent MAB (2-amino-1-methylbenzimidazole).New sorbent based on MN202 (Purolite) impregnated with organic reagents have been obtained and investigated. The sorbent characteristics determined using SEM, XRD and FTIR methods. The optimal conditions for the sorption of rhenium (VII) ions for the "element-sorbent" systems have been established. Under static conditions, the sorption of rhenium on impregnated sorbents in a sulfuric acid solution was studied in the periodic system with respect to the contact time, …

Synthesis Of Aromatic Acetylene Alcohols Using Complex Catalytic Systems, Odiljon Ziyadullaev, Guzal Otamukhamedova, Abduvakhab Ikramov, Saida Abdurakhmanova, Otabek Boytemirov

CHEMISTRY AND CHEMICAL ENGINEERING

Some cyclic ketones (cyclopentanone, cyclohexanone, 2-methylcyclohexanone, menthol, camphor and adamantanone) enantioselective alkynylation reactions with phenylacetylene have been studied in the presence of complex catalytic systems - Zn(OTf)₂/NЕt₃/MeCN, 3,3′-Ph₂BINOL-2Li/TGF and BuLi/KO^tBu/TGF. Synthesis were performed new aromatic acetylene alcohols – 1-(2-phenylathinyl) cyclopentanol (1), 1-(2-phenylethinyl)cyclohexanol (2), 2-methyl-1-(2-phenylethinyl)cyclohexanol (3), 2-isopropyl-5-methyl-1-(2-phenylethinyl)cyclohexanol (4), 1,7,7,-trimethyl-2-(2-phenylethinyl)bicyclo [2.2.1] heptanol-2 (5) and 2-phenylethinyltricyclo [3,3,1.0^3,7]nonanol-2 (6). Synthesis reactions of aromatic acetylene alcohols, activation energies were determined, kinetic of chemical changes and reaction mechanisms were proposed. The course of the reactions and the effect of the selected ketone molecule size, structure and …

Heterogeneous Catalytic Conversions Of Acetylene, Abduvakhab Ikramov, Sevara Kholikova, Noryigit Musulmanov

CHEMISTRY AND CHEMICAL ENGINEERING

The reactions of interaction of acetylene with water vapor, acetic acid and ammonia in the presence of heterogeneous catalysts have investigated. Depending on the nature of the starting components used, acetaldehyde and acetone, vinyl acetate, pyridine bases and pyrrole synthesized. Heterogeneous catalysts selected for each studied reaction based on some scientific prerequisites for the selection of catalysts. Active catalysts for the investigated reactions were determined, which contain compounds of cadmium, zinc, bismuth, chromium, iron and copper, in general, d-group metals. γ-Al₂O₃, bentonite and kaolin used as a catalyst carrier. Hydrofluoric acid, acetic acid, ammonium fluoride and …

Composite Elastomer Materials Based On New Ingredients, Akhmadjon Ibadullaev, Elmira Teshabaeva, Murodjon Vapaev

CHEMISTRY AND CHEMICAL ENGINEERING

The results of a study present the effect of new modified ingredients on the complex of properties of composite elastomeric materials. Methods for modifying mineral fillers have developed. It found that the introduction of modified ingredients into the composition of elastomeric compositions enhances the interfacial interaction at the “rubber-filler” interface and the formation of additional bonds between rubber macromolecules and functional groups, resulting in an improvement in the complex of properties of the compositions. New accelerators, activators for vulcanization of rubbers and plasticizers with stabilizing properties have proposed, and their optimal contents in the composition have determined.

Composition For Protecting Technological Equipment Against Salt Deposits And Internal Corrosion, Hasan Kadirov, Sadritdin Turabdjanov

CHEMISTRY AND CHEMICAL ENGINEERING

Aimed studies on the synthesis of metal complexonates have carried out. The reaction of obtaining zincate zincate oxyethylene diphosphonic acid OEDP has studied. On the basis of synthesized zincate-OEDP, compositions of corrosion inhibitors and deposits of mineral salts with the addition of a vacuum residue of monoethanolamine (RMEA) and polyaminocrotanol (PKI-3), which are able to effectively suppress corrosion processes in environments with different initial corrosive activity, have been compiled. It is proved that the high efficiency of the composition OEDP : zincate-OEDP : PKI-3 (maximum protective effect - 97.9%) is much more effective than the composition OEDP : zincate-OEDP : …

Rational Disposal Of Pet Containing Waste And Prospects For The Synthesis Of New Polymers, Asror Juraev, Muzaffar Alimukhamedov, Ravshan Adilov, Farhod Magrupov

CHEMISTRY AND CHEMICAL ENGINEERING

As a result of the research on the utilization of polyethylene terephthalate-containing household waste, a promising direction was identified in the production of a new type of secondary polyethylene terephthalate (SPET) - unsaturated polyesters.It was revealed that the final product, which formed when the alcoholization process is complete in any proportion of of glycol and secondary polyethylene terephthalate, is the bisalkylent terephthalate of terephthalic acid; the content of the alcoholysis product consists of bisalkylent terephthalate, different molecule mass, functionally hydroxyl-containing complex polyester polyol and free diols.

The laws of alcoholization of secondary …

Layered Bismuth Tungstate: Heterogeneous Photocatalysis For Environmental Remediation, Mirabbos Hojamberdiev, Zuhra Kadirova, Shahlo Daminova, Khasan Sharipov, Nobuhiro Matsushita

CHEMISTRY AND CHEMICAL ENGINEERING

Air and water pollution has been one of the challenging environmental issues in modern society. Since the Honda-Fujishima effect was first reported in 1972, a semiconductor-based photocatalysis has been regarded as one of the most green and economical processes for potential application in environmental remediation. Bismuth-based semiconductors are regarded as a promising group of advanced photocatalytic materials due to their suitable band gap for visible light response, an increased mobility of photo-generated charge carriers because of well-dispersed Bi 6s orbital, non-toxicity, and easy tailoring of their morphologies. To utilize its full potential in environmental remediation, various studies have been carried …

Sorption-Spectrometric Determination Of Nickel By Monoammonium Salt Of Glycirrizic Acid, Ugilay Abdurakhmanova, Khabibjon Kushiev

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of this work is to develop a sensitive, selective and rapid method for the determination of nickel ions using the monoammonium salt of glycyrrhizic acid as an analytical reagent. There obtained IR spectra of the nickel diglycyrrhizinate complex. A simple and express spectral method for determination of the nickel ion is presented. The optimal conditions for the determination of the nickel ion are found. Under optimal conditions, a gradual graph was drawn up, which is linear in the concentration range for nickel of 20.0–40.0 μg/25 ml, the composition of the complex of nickel with the monoammonium salt …

Features Of Chloridizing Roasting Of Almalyk Mining Metallurgical Combinate Wastes, Malokhat Atamuratova, Dildora Khakimboeva, Khasan Sharipov, Zuhra Kadirova, Tulkin Shakarov

CHEMISTRY AND CHEMICAL ENGINEERING

With the aim to develop a comprehensive technology for processing Almalyk Mining Metallurgical Combinate (AMMC) wastes, the influence of chloride additives on the copper and zinc chloride volatilization process is considered. The relationship between presence of the calcium, potassium and sodium chlorides chlorinating additive on the copper and zinc chlorides sublimation from the AGMK wastes at roasting temperatures up to 700-1000˚C was established.

The Role Of The 2,7-Dinitroso-1,8-Dihydroxynaphthalene-3,6-Disulfonic Acid Reagent In Determining The Thorium Ion (Iv), Nigora Qutlimurotova, Salohiddin Mahmadoliyev, Khabibullo Todjimukhamedov

CHEMISTRY AND CHEMICAL ENGINEERING

The aim is to develop a method for the amperometric determination of thorium (IV) ion with 2,7-dinitroso-1,8-dihydroxynaphthalene-3,6-disulfoxyl reagent. Methods of amperometric determination of thorium by solution of 2,7-dinitrozo-1,8-dihydroxynaphthalene-3,6-disulfonic acid on different acid-base properties of background electrolytes and buffer mixtures are considered. The half-wave potential of new reagent was found by logarithmic analysis equal 0.72 V at pH 2.82, which once again indicates on the irreversibility of the process of electrooxidation of the studied organic reagent in used acid-base medias. The conditions for amperometric titration of thorium are optimized, and the influence of outside accompanying metals on the shape of curves …

Synthesis Of Some N-Oxides Of Pyridylacethylene Amines Based On 2-Methyl-5-Ethynylpyridine, Abduvakhab Ikramov, Odiljon Ziyadullayev, Adkham Khamidjanov, Shavkat Bojariev, Davron Khandamov

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of this work is to study the reaction of 2-methyl-5-ethynylpyridine N-oxide with some aliphatic and aromatic amines to obtain N-oxides of pyridylacetylenic amines. 2-Methyl-5-ethylpyridine converted to 2-methyl-5-vinylpyridine by dehydrogenation, and 2-methyl-5-ethynylpyridine obtained by bromination and dehydrobromination. 2-methyl-5-ethynylpyridine N-oxide synthesized by oxidation of 2-methyl-5-ethynylpyridine with perhydrol in acetic anhydride. The synthesis of N-oxides of pyridylacetylenic amines by the Mannich reaction carried out. The effect of the solvents: methanol, ethanol and n-dioxane, the catalyst, and the reaction time on the yield of the final product studied. The structure and composition of the synthesized PAA N-oxides were established using IR and …

The Role Of Hydrogen Bonds In Diluted Ethanol Solutions Of Cyclohexane And Dimethylformamide, Dilbar Bozorova, Shukur Gofurov, Mavlonbek Ziyayev, Dildora Mirtojiyeva, Odina Ismanova, Oksana Ismoilova

CHEMISTRY AND CHEMICAL ENGINEERING

The refractometric method and Fourier transform infrared spectroscopy were used to determine the optical features of the concentration characteristics of diluted ethanol solutions of cyclohexane and dimethylformamide. It was found for the first time that at some concentrations the hydrogen bond is stronger than for a pure ethanol solution. The first maximum of the excess refractive index of solutions is formed at a concentration of 0.02 mole fraction of cyclohexane and dimethylformamide, which is in good correlation with IR spectroscopy, indicating the largest number of formed hydrogen bonds.

Synthesis Of Superabsorbing Hydrogels Based On Starch Copolymers, Baxodir Kholnazarov, Khayit Turaev, Abdulakhat Jalilov

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of this work is to synthesize highly swellable superabsorbent hydrogels based on starch copolymers. To achieve this goal, mineral-containing superabsorbent hydrogels based on starch, acrylamide, binder and initiator were synthesized. The optimal synthesis conditions were determined and studies were carried out on the influence of the molar ratios of the starting substances on the composition and physicochemical properties of the synthesized superabsorbent hydrogel. In the course of research, the optimum copolymerization temperature was 60 ° C, and the reaction time was 3 hours.

As a result of the study, a superabsorbent hydrogel based on starch, acrylamide and bentonite …

Synthesis Of Thiocol Oligomer Based On Sodium Tetrasulphide, Epichlorhydrine And Ammonium Phosphate, Bakhtiyor Normurodov, Khayit Turaev, Abdulakhat Jalilov, Sherzod Kasimov

CHEMISTRY AND CHEMICAL ENGINEERING

The purpose of this study is the synthesis and study of thiokol oligomer NEP-12 brand based on sodium tetrasulfide, epichlorohydrin and ammonium phosphate, which is intended for use as a main component of Thiokol sealant. To achieve this goal, a thiokol oligomer based on sodium tetrasulfide, epichlorohydrin, and ammonium phosphate was synthesized and investigated, and the optimal conditions for the synthesis of a thiokol oligomer were determined. Research has been carried out on the influence of the molar ratios of the starting substances on the composition and physicochemical properties of the synthesized thiocol oligomer. The optimum polycondensation temperature was taken …

Synthesis And Structure Of The Coordination Complex Of Copper Ion With Collagen, Dildorа Sadikova, Adham Rafikov, Oybek Tursunqulov, Dilnoza Soyibova

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of this work is to synthesize, determine the composition and microstructure of complexes of copper (II) sulfate with collagen for use as a dye for textile material. Coordination complexes of copper (II) sulfate with collagen synthesized at different ratios of the initial substances by the interaction of solutions of different concentrations of copper sulfate and collagen of raw skin. With an increase in the salt content, the yield of the reaction product increases. With an excess of collagen, some of it does not bind into a complex and precipitates. With an excess of salt, almost the weight of …

Synthesis Of Sodium Ammonium Hydrophosphate And Sodium Dihydrophosphate Based On Extraction Phosphoric Acid From Central Kyzylkum Phosphorites, Kamola Arifdjanova, Kholtura Mirzakulov, Sherzod Khujamberdiev, Melikulova Gavkhar

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of the research is the synthesis of sodium ammonium hydrogen phosphate and sodium dihydrogen phosphate based on purified extraction phosphoric acid.

The acid was purified from accompanying impurities by precipitation methods using sodium carbonate and metasilicate, washed burnt phosphoconcentrate, barium carbonate, acid neutralization with gaseous ammonia. Pre-neutralization of the purified solution of monoammonium phosphate with sodium carbonate to the ratio Na₂O:P₂O₅ = 0.44 and subsequent drying at a temperature of 50 °С allows to obtain sodium ammonium hydrogen phosphate tetrahydrate, and at 100 °С sodium dihydrogen phosphate monohydrate.

The individuality and purity of …

Sorption Of Ions Of Some Metals On Synthesized Weakly Basic Ion Exchangers, Dilmurod Azimov, S. Turabjanov, Farrukh Igitov, Rano Nazirova, Tulkin Tursunov

CHEMISTRY AND CHEMICAL ENGINEERING

The purpose of the study is to test a weakly basic anion exchanger of the polycondensation type in the processes of sorption of ions of copper, nickel, cobalt, zinc, cadmium. Among the indicated metal ions, the maximum sorption was established for copper ions.

To study the process of sorption of copper ions by the tested anion exchanger, the method of potentiometric titration was used. It was found that copper ions are sorbed by the anion exchanger in the form of a complex in the range of pH = 3,4-4,2. The formation of the copper ions complexes decreases with an increase …

Fabrication And Characterization Of Highly Ordered Aao Nanotubes, Anvar Khamidov, Farhod Hoshimov, Suvonkul Erkhanovich Nurmonov, Olim Ruzimuradov, Shavkat Mamatkulov

CHEMISTRY AND CHEMICAL ENGINEERING

Investigated the electrochemical synthesis and characterized of a nanometer scale porous anodic aluminum oxide (AAO) membranes with a mean pore diameter about of 80-100 nm. The anodizing process done by varying the anodizing temperature from 20 °C to 25 °C. The membranes exhibit interesting properties such as controllable pore diameters, periodicity and density distribution. These properties can preselected by adjusting the controlling parameters of a temperature controlled two-step anodization process. The surface features of the nanometer scale membrane such as pore density, pore diameter and interpore distance were quantified using scanning electron microscopy (SEM) and atomic force microscopy (AFM). SEM …

Physico-Chemical Properties And Structural Transformations In The Synthesis Of Boroalumosilicate Glass-Crystal Materials, Julia Yeganyan

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of this work is to study the areas of glass formation and metastable liquation of the pseudo-ternary system (MgO·Al₂O₃)-B₂O₃-SiO₂, and study of the crystallization process of glasses of cordierite composition. The crystallization process of glasses of cordierite composition containing B₂O₃ by a single-stage heat treatment at 1000 ^oC and 1200 ^oC, the nature of crystallization, the thermal properties of glasses and glass crystalline materials of the system (MgO·A_l2O₃)-B₂O₃-SiO₂ were studied. It revealed that during …

Physical And Chemical Properties, Elemental Composition And Microbiological Purity Of Oil Extract Of Chamomile Flowers In Bitter Almond Oil, Khakim Tukhtaev, Sevara Khazratkulova

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of the study was to obtain an oil extract with the participation of chamomile officinalis (Matrigaria Recutito) grown in the Tashkent region using bitter almond oil (Amygdalus communis L.). Its chromatographic and elemental analyzes have been carried out, its microbiological purity and physicochemical constants have been determined. For extraction, we used bitter almond oil obtained by cold pressing. Extraction of chamomile flowers in bitter almond oil was carried out by maceration in the ratio of raw material: solvent (1:10). Analysis of fatty acids in the fatty extract was carried out chromatographically. The fatty extract was found to contain …

Obtaining Of Bacterial Polysaccharides, Kulonov Abdulaziz, Mirzarakhmetova Dilbar, Turaeva Nigora

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of this work was to develop a technology for obtaining bacterial exopolysaccharides. The problem was solved by using the bacterial strain Halovibrio variabilis UzAS3 as a polysaccharide producer. The optimal parameters of bacterial cultivation have been determined. A technological scheme for obtaining bacterial polysaccharides has been developed, which includes such stages as the cultivation of bacteria, the separation of bacterial biomass from the culture liquid, desalting, precipitation, washing and drying. The obtained results show that bacteria have a high potential for the yield of bacterial exopolysaccharides (7.1-9.5 mg/ml).