Pub Date : 2018-12-12DOI: 10.6060/IVKKT.20186112.5720
A. Agafonov, K. V. Ivanov, O. Alekseeva
Barium titanate powder with average particle size near 300 nm was produced using the low-temperature synthesis. It was established using scanning electron microscopy that at the thermal treatment, the particles gradually decrease with the formation of polydisperse aggregates. Based on the thermogravimetric analysis of the synthesized powder held in air for 4 months, it was shown that along with the low-temperature phase, the sample contains a high-temperature phase of carbonates, which removes at ~ 900 °C. Sorption characteristics of barium titanate thermally treated at various temperatures were obtained from the results of adsorption-desorption of nitrogen vapors. The specific surface area of the BaTiO3 powder was 76 m2/g. It was found that further heat treatment leads to a decrease in the specific surface area. The X-ray diffraction analysis of barium hydroxotitanil annealed at temperatures from 120 °C to 800 °C showed that the thermal treatment of the sample leads to the formation of a completely formed phase of barium titanate. The DSC temperature was used to determine the Curie temperatures for a HTB powder thermally treated in the temperature range from 120 to 800 °C. Dielectric spectra of suspensions of the synthesized powder were obtained during the heat treatment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
{"title":"LOW-TEMPERATURE SYNTHESIS OF BARIUM TITANITE IN AQUEOUS SOLUTION","authors":"A. Agafonov, K. V. Ivanov, O. Alekseeva","doi":"10.6060/IVKKT.20186112.5720","DOIUrl":"https://doi.org/10.6060/IVKKT.20186112.5720","url":null,"abstract":"Barium titanate powder with average particle size near 300 nm was produced using the low-temperature synthesis. It was established using scanning electron microscopy that at the thermal treatment, the particles gradually decrease with the formation of polydisperse aggregates. Based on the thermogravimetric analysis of the synthesized powder held in air for 4 months, it was shown that along with the low-temperature phase, the sample contains a high-temperature phase of carbonates, which removes at ~ 900 °C. Sorption characteristics of barium titanate thermally treated at various temperatures were obtained from the results of adsorption-desorption of nitrogen vapors. The specific surface area of the BaTiO3 powder was 76 m2/g. It was found that further heat treatment leads to a decrease in the specific surface area. The X-ray diffraction analysis of barium hydroxotitanil annealed at temperatures from 120 °C to 800 °C showed that the thermal treatment of the sample leads to the formation of a completely formed phase of barium titanate. The DSC temperature was used to determine the Curie temperatures for a HTB powder thermally treated in the temperature range from 120 to 800 °C. Dielectric spectra of suspensions of the synthesized powder were obtained during the heat treatment. \u0000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .","PeriodicalId":45993,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenii Khimiya i Khimicheskaya Tekhnologiya","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2018-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41766428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-12-12DOI: 10.6060/ivkkt20186100.5728
Yu. V. Chursanov, V. Lutsik, Anatoly V. Starovoytov
Cyanidation remains the predominant technology for the dissolution of gold from mineral raw materials. Environmental and technological disadvantages in the use of cyanides are the cause of the development of alternative systems, which include reagent-oxidant and reagent-complexant. A special place is occupied by the solvents, in which the formation of heteroligand complexes of gold is possible. Thus due to the formation of more durable compounds the rate of dissolution of the metal increases. In this work, as the ligands the thiourea and the ions of thiosulfate in the form of sodium salt were used, as the oxidant – complex of the iron (III) and EDTA. The influence of the mixed solvent composition on the kinetic characteristics and the reaction mechanism was studied by the rotating disc method. To confirm the role of different ligand complexes, the dependence of the dissolution rate of gold by the mixed system – thiosulphate and thiourea in the isomolar series, was determined. With a constant total ligands concentration, the molar ratio of reagents was changing. On the basis of the data obtained, a mathematical model of the process of oxidative dissolution of gold is proposed. A characteristic feature of the calculated results is a substantial increase in the reaction constants for the formation of heteroligand complexes, which confirms their role in the process of gold oxidation. The influence of pH and concentration of oxidant and ligand-forming substances on the kinetics of gold dissolution is established. To elucidate the mechanism of the limiting stage of the heterophase process, the experimental activation energy is calculated and the effect of the disk rotation frequency on the dissolution rate is studied. The experimental activation energy is 28.1 kJ/mol. The order by the disk rotation frequency is 0.35. Evaluation of the contribution of the diffusion and kinetic components of rate is estimated on the basis of the modified Levich equation for the mixed regime. Diffusion component of rate is almost an order of magnitude smaller than the kinetic one. Calculation of the diffusion flux of the supplied reagents showed that the only process that inhibits mass transfer is the diffusion of the reaction products from the surface of the rotating disc. The formation of more durable heteroligand complexes and a greater equilibrium constant of the oxidation reaction lead to an increase in the concentration of products at the surface and, consequently, to an increase in the rate of diffusion of the metal into the solution. An important factor affecting the oxidation of gold in the system studied is the formation of intermediate solid reaction products on the metal surface. To identify solid products, IR spectra of reflection of polished gold surface after etching in the system studied were obtained. A strong absorption band in the 808-762 cm-1 region is observed on the spectra. Absorption in this region is associated with valence symmetrical vibrations
{"title":"DISSOLUTION KINETICS OF GOLD IN SYSTEM THIOUREA–THIOSULFATE WITH OXIDANT OF Fe(III)EDTA","authors":"Yu. V. Chursanov, V. Lutsik, Anatoly V. Starovoytov","doi":"10.6060/ivkkt20186100.5728","DOIUrl":"https://doi.org/10.6060/ivkkt20186100.5728","url":null,"abstract":"Cyanidation remains the predominant technology for the dissolution of gold from mineral raw materials. Environmental and technological disadvantages in the use of cyanides are the cause of the development of alternative systems, which include reagent-oxidant and reagent-complexant. A special place is occupied by the solvents, in which the formation of heteroligand complexes of gold is possible. Thus due to the formation of more durable compounds the rate of dissolution of the metal increases. In this work, as the ligands the thiourea and the ions of thiosulfate in the form of sodium salt were used, as the oxidant – complex of the iron (III) and EDTA. The influence of the mixed solvent composition on the kinetic characteristics and the reaction mechanism was studied by the rotating disc method. To confirm the role of different ligand complexes, the dependence of the dissolution rate of gold by the mixed system – thiosulphate and thiourea in the isomolar series, was determined. With a constant total ligands concentration, the molar ratio of reagents was changing. On the basis of the data obtained, a mathematical model of the process of oxidative dissolution of gold is proposed. A characteristic feature of the calculated results is a substantial increase in the reaction constants for the formation of heteroligand complexes, which confirms their role in the process of gold oxidation. The influence of pH and concentration of oxidant and ligand-forming substances on the kinetics of gold dissolution is established. To elucidate the mechanism of the limiting stage of the heterophase process, the experimental activation energy is calculated and the effect of the disk rotation frequency on the dissolution rate is studied. The experimental activation energy is 28.1 kJ/mol. The order by the disk rotation frequency is 0.35. Evaluation of the contribution of the diffusion and kinetic components of rate is estimated on the basis of the modified Levich equation for the mixed regime. Diffusion component of rate is almost an order of magnitude smaller than the kinetic one. Calculation of the diffusion flux of the supplied reagents showed that the only process that inhibits mass transfer is the diffusion of the reaction products from the surface of the rotating disc. The formation of more durable heteroligand complexes and a greater equilibrium constant of the oxidation reaction lead to an increase in the concentration of products at the surface and, consequently, to an increase in the rate of diffusion of the metal into the solution. An important factor affecting the oxidation of gold in the system studied is the formation of intermediate solid reaction products on the metal surface. To identify solid products, IR spectra of reflection of polished gold surface after etching in the system studied were obtained. A strong absorption band in the 808-762 cm-1 region is observed on the spectra. Absorption in this region is associated with valence symmetrical vibrations ","PeriodicalId":45993,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenii Khimiya i Khimicheskaya Tekhnologiya","volume":"1 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2018-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71162615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-12-12DOI: 10.6060/IVKKT.20186112.5835
Yu. V. Polenov, G. A. Shestakov, E. Egorova
A stoichiometric mechanism for full thiourea dioxide decomposition in aqueous solution under pH of 4.0 is proposed based on dependences of concentrations of thiourea dioxide and its decomposition products on the time and literature data. The concentration of thiourea dioxide was measured via iodometry, while the intermediates were quantified using the polarography. Polarography was carried out in glass two-electrode electrochemical cell by means of PU-1 polarograph in differential mode. Dropping mercury electrode was used as working one and silver chloride as a reference one. Rate constants for individual stages are obtained via mathematical modeling, presented a system of differential equations. Absolute errors of rate constants, correlation coefficients, and F-factors were also calculated. Verification of supposed kinetic model was conducted using the comparison between experimental and calculated concentrations, F-test and the calculated values of correlation coefficients of the individual stages of the process. Supposed kinetic model of decomposition consists of a number of consequent stages including various compounds such as sulfur monoxide, thiosulfuric, sulfuric, dithionic, hydrosulfuric acids as intermediates was used for previously obtained data for pH of 8.85. To test the universality of supposed model, we simulated kinetics of thiourea dioxide decomposition reaction at pH of 8.85. Experimental kinetic data were taken from literature. The initial approximations of the individual stages constants were taken from previous calculations. Analysis of calculated data: concentration values, F-test, correlation coefficients allowed to conclude about the applicability of proposed mechanism for the process of thiourea dioxide decomposition in a weakly alkaline medium.
{"title":"KINETIC MODEL OF THIOUREA DIOXIDE DECOMPOSITION IN AQUEOUS SOLUTIONS OF DIFFERENT ACIDITY","authors":"Yu. V. Polenov, G. A. Shestakov, E. Egorova","doi":"10.6060/IVKKT.20186112.5835","DOIUrl":"https://doi.org/10.6060/IVKKT.20186112.5835","url":null,"abstract":"A stoichiometric mechanism for full thiourea dioxide decomposition in aqueous solution under pH of 4.0 is proposed based on dependences of concentrations of thiourea dioxide and its decomposition products on the time and literature data. The concentration of thiourea dioxide was measured via iodometry, while the intermediates were quantified using the polarography. Polarography was carried out in glass two-electrode electrochemical cell by means of PU-1 polarograph in differential mode. Dropping mercury electrode was used as working one and silver chloride as a reference one. Rate constants for individual stages are obtained via mathematical modeling, presented a system of differential equations. Absolute errors of rate constants, correlation coefficients, and F-factors were also calculated. Verification of supposed kinetic model was conducted using the comparison between experimental and calculated concentrations, F-test and the calculated values of correlation coefficients of the individual stages of the process. Supposed kinetic model of decomposition consists of a number of consequent stages including various compounds such as sulfur monoxide, thiosulfuric, sulfuric, dithionic, hydrosulfuric acids as intermediates was used for previously obtained data for pH of 8.85. To test the universality of supposed model, we simulated kinetics of thiourea dioxide decomposition reaction at pH of 8.85. Experimental kinetic data were taken from literature. The initial approximations of the individual stages constants were taken from previous calculations. Analysis of calculated data: concentration values, F-test, correlation coefficients allowed to conclude about the applicability of proposed mechanism for the process of thiourea dioxide decomposition in a weakly alkaline medium.","PeriodicalId":45993,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenii Khimiya i Khimicheskaya Tekhnologiya","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2018-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42489759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-12-12DOI: 10.6060/IVKKT.20186112.5799
Tatyana V. Кudayarova, M. A. Tyutina, Е. A. Danilova
This work is continuation of synthesis researches of substituted macroheterocyclic compounds with 1,2,4-thiadiazole fragments. Data of synthesis of complexes with divalent d-metals (Ni, Co, Zn) on the basis of received earlier brominenitrosubstituted isothiadiazole three-unit product are presented. Complexes of BAB-type product consisting 1,2,4-thiadiazole and bromine-nitro-isoindole fragments were received by interaction 3,5-bis-[5(6)-bromine-6(5)-nitro-3-iminoizoindolin-1-ilidenamiino]-1,2,4-thiadiazol with acetates of d-metals in 2-ethoxyethanol at 100 ºC for 2 h. After the reaction the mixture was poured into water and precipitate was filtered and washed with 5 % ammonia, water and hot organic solvents (acetone, methanol, dimethylformamide, pyridine). Yield of target products was 18 – 28 %. The resulting complexes are dark brown powders with high solubility in alcohols, DMF, insoluble in water, dichloromethane and hexane. The structures of products were established by data of mass spectrometry, elemental analysis, UV-vis and IR spectroscopy. Data of MALDI-TOF mass spectrometry showed that complexes with metal of three-unit product with 1,2,4-thiadiazole fragment were isolated as monohydrate by analogy with literary for 1,3,4-thiadiazole. Data of atomic absorption analysis with good convergence of the experimental and calculated values confirmed monohydrate structure these products. These complexes of three-unit products will be used for synthesis of new various substituted macroheterocycles with 1,2,4-thiadiazole fragments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
{"title":"COMPLEXES OF IZOTHIADIAZOLE-CONTAINING BROMONITROSUBSTITUTED THREE UNITS PRODUCT WITH D-METALS (NI, CO, ZN)","authors":"Tatyana V. Кudayarova, M. A. Tyutina, Е. A. Danilova","doi":"10.6060/IVKKT.20186112.5799","DOIUrl":"https://doi.org/10.6060/IVKKT.20186112.5799","url":null,"abstract":"This work is continuation of synthesis researches of substituted macroheterocyclic compounds with 1,2,4-thiadiazole fragments. Data of synthesis of complexes with divalent d-metals (Ni, Co, Zn) on the basis of received earlier brominenitrosubstituted isothiadiazole three-unit product are presented. Complexes of BAB-type product consisting 1,2,4-thiadiazole and bromine-nitro-isoindole fragments were received by interaction 3,5-bis-[5(6)-bromine-6(5)-nitro-3-iminoizoindolin-1-ilidenamiino]-1,2,4-thiadiazol with acetates of d-metals in 2-ethoxyethanol at 100 ºC for 2 h. After the reaction the mixture was poured into water and precipitate was filtered and washed with 5 % ammonia, water and hot organic solvents (acetone, methanol, dimethylformamide, pyridine). Yield of target products was 18 – 28 %. The resulting complexes are dark brown powders with high solubility in alcohols, DMF, insoluble in water, dichloromethane and hexane. The structures of products were established by data of mass spectrometry, elemental analysis, UV-vis and IR spectroscopy. Data of MALDI-TOF mass spectrometry showed that complexes with metal of three-unit product with 1,2,4-thiadiazole fragment were isolated as monohydrate by analogy with literary for 1,3,4-thiadiazole. Data of atomic absorption analysis with good convergence of the experimental and calculated values confirmed monohydrate structure these products. These complexes of three-unit products will be used for synthesis of new various substituted macroheterocycles with 1,2,4-thiadiazole fragments. \u0000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . \u0000 ","PeriodicalId":45993,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenii Khimiya i Khimicheskaya Tekhnologiya","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2018-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43836050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-12-12DOI: 10.6060/ivkkt.20186112.5708
Evgeniy S. Vavilov, A. Biryukov, I. Kovalev, A. V. Tolchev
Multi-layered carbon nanotubes were synthesized via hydrocarbons pyrolysis method in the presence of argon overpressure in the reaction system. With the use of the scanning electron microscope method, a morphology of the obtained materials were investigated. Synthetized nanotubes were modified by treating with solutions of various reagents: sodium hydroxide (10 mass. %), azotic (40 mass. %) and perchloric (40 mass. %) acids, chloroform. The sample was placed in the reagent solution with the volume of 10 ml and exposed for 24 h. Electrophysical investigation of multi-layered carbon nanotubes dispersions with zinc sulfate additions was carried with the use of the impedance meter Z - 1500J in a range of frequencies of 10 Hz - 2 MHz. It was found that the carbon nanomaterials effect on the electrophysical properties of zinc electrolyte. A change in electrical conductivity of zinc sulfate solutions with the addition of multi-layered carbon nanotubes with various morphology and surface modifications was studied. With the use of impedance spectroscopy method, there were examined the electrophysical properties of zinc electrolyte with additions of carbon nanotubes in the presence of various components concentration and pH level of the environment, that was obtained via the original technique. It is shown that electron conduction increases with the rise of nanotubes concentration, but substantially levels with the rise of zinc sulfate concentration. Moreover, insertion of multi-layered carbon nanotubes in the solution changes a state of equivalent circuit and its elements. It is concluded that insert of multi-layered carbon nanotubes has unambiguous impact on the electrophysical properties of zinc sulfate solutions. Based on the obtained data, a scheme of electrolyte and nanotubes interaction is offered.
{"title":"ELECTROPHYSICAL PROPERTIES OF ZINC SULFATE SOLUTIONS IN PRESENCE OF WATER DISPERSION OF MULTI-LAYERED CARBON NANOTUBES","authors":"Evgeniy S. Vavilov, A. Biryukov, I. Kovalev, A. V. Tolchev","doi":"10.6060/ivkkt.20186112.5708","DOIUrl":"https://doi.org/10.6060/ivkkt.20186112.5708","url":null,"abstract":"Multi-layered carbon nanotubes were synthesized via hydrocarbons pyrolysis method in the presence of argon overpressure in the reaction system. With the use of the scanning electron microscope method, a morphology of the obtained materials were investigated. Synthetized nanotubes were modified by treating with solutions of various reagents: sodium hydroxide (10 mass. %), azotic (40 mass. %) and perchloric (40 mass. %) acids, chloroform. The sample was placed in the reagent solution with the volume of 10 ml and exposed for 24 h. Electrophysical investigation of multi-layered carbon nanotubes dispersions with zinc sulfate additions was carried with the use of the impedance meter Z - 1500J in a range of frequencies of 10 Hz - 2 MHz. It was found that the carbon nanomaterials effect on the electrophysical properties of zinc electrolyte. A change in electrical conductivity of zinc sulfate solutions with the addition of multi-layered carbon nanotubes with various morphology and surface modifications was studied. With the use of impedance spectroscopy method, there were examined the electrophysical properties of zinc electrolyte with additions of carbon nanotubes in the presence of various components concentration and pH level of the environment, that was obtained via the original technique. It is shown that electron conduction increases with the rise of nanotubes concentration, but substantially levels with the rise of zinc sulfate concentration. Moreover, insertion of multi-layered carbon nanotubes in the solution changes a state of equivalent circuit and its elements. It is concluded that insert of multi-layered carbon nanotubes has unambiguous impact on the electrophysical properties of zinc sulfate solutions. Based on the obtained data, a scheme of electrolyte and nanotubes interaction is offered. \u0000 ","PeriodicalId":45993,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenii Khimiya i Khimicheskaya Tekhnologiya","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2018-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43744657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-12-11DOI: 10.6060/IVKKT.20186112.5896
C. Gatumel, H. Berthiaux, E. MizonovVadim
Powder mixing is a part of our everyday life, but is the source of major industrial preoccupations. Mixing is widely used in many industries but until now design of mixing technology and mixing equipment belongs sooner to engineering art than to scientifically based calculation. Each branch of industry develops its own experience in the field mostly based on time and labour consuming expe-rimental research, and very often the obtained results cannot be used directly in another branch, i.e., the problem of mixing simulation and calculation is far from universality. This is why it is very im-portant to separate from particular sectorial problems the general intersectorial problems of theory and practice of mixing and concentrate the attention of researchers and engineers on them solution to build the general basis for scientifically based design of mixing technology and equipment. Current problems are associated with the definition of the homogeneity of the mixtures, the ways of measuring it, the sampling errors and techniques, the segregability of the mixtures in the powder handling operations, mixer choice, as well as mixer conception. In this paper, we review such aspects and try to draw some perspectives from a combined industrial experience – chemical engineering approach: the development of on-line monitoring techniques to assess homogeneity and further con-trol the process; the improvement of mixer’s scale up procedures, as well as the optimisation of mixer design and operation; the development of new mixing technologies, multifunctional, nearly “universal”, with a special emphasis on continuous processes; the completion of the actual standards on powder homogeneity by introducing structural information.
{"title":"INDUSTRIAL MIXING OF PARTICULATE SOLIDS: PRESENT PRACTICES AND FUTURE EVOLUTION","authors":"C. Gatumel, H. Berthiaux, E. MizonovVadim","doi":"10.6060/IVKKT.20186112.5896","DOIUrl":"https://doi.org/10.6060/IVKKT.20186112.5896","url":null,"abstract":"Powder mixing is a part of our everyday life, but is the source of major industrial preoccupations. Mixing is widely used in many industries but until now design of mixing technology and mixing equipment belongs sooner to engineering art than to scientifically based calculation. Each branch of industry develops its own experience in the field mostly based on time and labour consuming expe-rimental research, and very often the obtained results cannot be used directly in another branch, i.e., the problem of mixing simulation and calculation is far from universality. This is why it is very im-portant to separate from particular sectorial problems the general intersectorial problems of theory and practice of mixing and concentrate the attention of researchers and engineers on them solution to build the general basis for scientifically based design of mixing technology and equipment. Current problems are associated with the definition of the homogeneity of the mixtures, the ways of measuring it, the sampling errors and techniques, the segregability of the mixtures in the powder handling operations, mixer choice, as well as mixer conception. In this paper, we review such aspects and try to draw some perspectives from a combined industrial experience – chemical engineering approach: the development of on-line monitoring techniques to assess homogeneity and further con-trol the process; the improvement of mixer’s scale up procedures, as well as the optimisation of mixer design and operation; the development of new mixing technologies, multifunctional, nearly “universal”, with a special emphasis on continuous processes; the completion of the actual standards on powder homogeneity by introducing structural information. \u0000 ","PeriodicalId":45993,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenii Khimiya i Khimicheskaya Tekhnologiya","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2018-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45222295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-12-10DOI: 10.6060/IVKKT.20186112.5914
A. Labutin, V.Yu. Nevinitsyn, V. A. Zaytsev, G. Volkova
A liquid-phase continuous stirred tank reactor equipped with a mechanical stirrer and cooling jacket is considered as a control object. The reactor operates in the polytropic mode. The multistep series-parallel exothermic process is carried out in the reactor. The objective of chemical reactor operation is to obtain the key product of specified concentration. The paper deals with analytical synthesis of automatic concentration control system of target product which provides invariance, covariance to the given actions, asymptotic stability and robustness under the action of uncontrollable parametric and signal disturbances. The astatic control law obtained using the synergetic control theory is proposed. Using the method of analytical design of aggregated regulators (ADAR) for a given invariant manifold, a non-linear control algorithm with an integral part was synthesized which solves the problem of stabilization of the concentration of target component on the exit of the reactor at the given value under the action of disturbances on the object. Algorithmic synthesis of the control law is carried out using a non-linear mathematical model of the object without the use of the linearization procedure. As a result of simulation it was found that the closed-loop control system has no static control error under the action of uncontrollable parametric and signal disturbances on the object, changes in the set points and initial deviation of the state variables from the static values. Consequently, the proposed non-linear concentration control algorithm has the property of robustness. The obtained results indicate the effectiveness of the ADAR method and the prospects of the synergetic control theory for solving problems of algorithmic synthesis of control systems of non-linear, multi-dimensional and multi-connected technological objects. The integration of the synthesized control law of chemical reactor at the design stage will allow implementing flexible cybernetically organized chemical-technological systems.
{"title":"ROBUST CONCENTRATION CONTROL OF TARGET PRODUCT IN CHEMICAL REACTOR","authors":"A. Labutin, V.Yu. Nevinitsyn, V. A. Zaytsev, G. Volkova","doi":"10.6060/IVKKT.20186112.5914","DOIUrl":"https://doi.org/10.6060/IVKKT.20186112.5914","url":null,"abstract":"A liquid-phase continuous stirred tank reactor equipped with a mechanical stirrer and cooling jacket is considered as a control object. The reactor operates in the polytropic mode. The multistep series-parallel exothermic process is carried out in the reactor. The objective of chemical reactor operation is to obtain the key product of specified concentration. The paper deals with analytical synthesis of automatic concentration control system of target product which provides invariance, covariance to the given actions, asymptotic stability and robustness under the action of uncontrollable parametric and signal disturbances. The astatic control law obtained using the synergetic control theory is proposed. Using the method of analytical design of aggregated regulators (ADAR) for a given invariant manifold, a non-linear control algorithm with an integral part was synthesized which solves the problem of stabilization of the concentration of target component on the exit of the reactor at the given value under the action of disturbances on the object. Algorithmic synthesis of the control law is carried out using a non-linear mathematical model of the object without the use of the linearization procedure. As a result of simulation it was found that the closed-loop control system has no static control error under the action of uncontrollable parametric and signal disturbances on the object, changes in the set points and initial deviation of the state variables from the static values. Consequently, the proposed non-linear concentration control algorithm has the property of robustness. The obtained results indicate the effectiveness of the ADAR method and the prospects of the synergetic control theory for solving problems of algorithmic synthesis of control systems of non-linear, multi-dimensional and multi-connected technological objects. The integration of the synthesized control law of chemical reactor at the design stage will allow implementing flexible cybernetically organized chemical-technological systems.","PeriodicalId":45993,"journal":{"name":"Izvestiya Vysshikh Uchebnykh Zavedenii Khimiya i Khimicheskaya Tekhnologiya","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2018-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43434022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-10-26DOI: 10.6060/IVKKT.20186109-10.5651
N. Kondrasheva, A. Eremeeva, Konstantin S. Nelkenbaum
The researches related to the development of the best composition and production of environmentally friendly diesel fuel, compliance with the EURO-5 and EURO-6 class, by introducing antiwear additives into the base hydrotreated fuel were conducted. The analysis of modern assumptions to the use in Russia of anti-wear additives of domestic and foreign manufacturers, such manufacturers as Clariant, BASF, Infinéum, JSC "AZKiOС" and others was carried out, and also the main results of efficiency of use of additives for diesel fuel are considered. The synthesis of antiwear additives and antioxidant additives from plant raw materials through the process of transesterification was carried out, as well as the technology of obtaining nitrogen and oxygen-containing compounds with surface active properties was developed. The optimal technological processes of the transesterification process (time, temperature, rate, ratio of raw materials) were revealed. The effect of the obtained bioadditives on the operational and low-temperature properties of hydrotreated diesel fuel was studied. Analysis of the positive effect of additives on lubricating properties of fuel showed that the diameter of the wear spot is reduced by a factor of 4, the amount of harmful emissions (carbon oxides, dispersed particles, volatile organic compounds and hydrocarbons) is reduced by more than 30 times. Also, a decrease in the pour point and change in the cetane number was observed, depending on the composition of the bioadditives (in some cases, the cetane number decreased and ceased to meet the requirements of the standard for diesel fuel GOST R 52368, while others, on the contrary, increased). A distinctive feature of this type of fuel is the maintenance of the minimum amount of gray in your composition, and at the same time compliance with all requirements of GOST. For citation: Kondrasheva N.K., Eremeeva A.М., Nelkenbaum K.S. Development of domestic technologies of produsing high quality clean diesel fuel. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 9-10. P. 76-82
通过在基础加氢处理燃料中引入抗磨添加剂，对开发符合EURO-5和EURO-6级标准的环保柴油的最佳成分和生产进行了相关研究。分析了国内外生产商如科莱恩、巴斯夫、英飞凌、JSC“AZKiOС”等对俄罗斯抗磨添加剂使用的现代假设，并考虑了柴油添加剂使用效率的主要结果。以植物为原料，通过酯交换反应合成了抗磨添加剂和抗氧化添加剂，并开发了获得具有表面活性的含氮、含氧化合物的技术。揭示了酯交换工艺的最佳工艺流程（时间、温度、速率、原料配比）。研究了所得生物添加剂对加氢柴油操作性能和低温性能的影响。对添加剂对燃料润滑性能的积极影响的分析表明，磨损点的直径减少了4倍，有害排放量（碳氧化物、分散颗粒、挥发性有机化合物和碳氢化合物）减少了30多倍。此外，根据生物添加剂的组成，观察到倾点降低和十六烷值变化（在某些情况下，十六烷值降低并不再满足柴油GOST R 52368标准的要求，而另一些情况则相反，十六烷数增加）。这种燃料的一个显著特点是保持成分中的最小灰色量，同时符合GOST的所有要求。引用：Kondrasheva N.K.，Eremeeva A.М.，Nelkenbaum K.S.国内生产高品质清洁柴油技术的发展。伊兹夫。维什。Uchebn。扎维德。Khim。Khim。Tekhnol。2018年第61条。N 9-10。第76-82页
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Pub Date : 2018-10-26DOI: 10.6060/ivkkt.20196201.5760
N. F. Ushmarin, Egor G. Efimovskii, N. N. Petrova, S. I. Sandalov, N. I. Kol’tsov
In the article two rubber mixtures are studied: rubber 7NO-68-1SK based on a combination of butadiene-nitrile caoutchouc BNKS-18AMN with chloroprene caoutchouc neoprene W and rubber 81-453 based on a combination of butadiene-nitrile caoutchouc BNKS-40AMN, butadiene caoutchouc SKD, butadiene-methylstyrene caoutchouc SKMS-30 ARK and sevilene 11808-340. The purpose of the study was to improve the physical-mechanical and operational properties of both rubber mixtures by using fine powdered schungites Taurit TS-D, Psh-5 and PSH-20 in their composition. To assess the kinetics of vulcanization of rubber mixtures, the following were determined: the minimum and maximum torques; start time, optimum time, time achieving maximum vulcanization rate and maximum of vulcanization rate. To assess the physical-mechanical properties, we determined: the conditional tensile strength; elongation at break; hardness and relative residual deformation after compression. To evaluate the performance properties of rubbers, the following was determined: the change in the relative tensile strength; change in elongation at break and change in mass after aging of vulcanizates in a standard liquid SZHR-1, isooctane + toluene mixture, as well as in gasoline and industrial oil I-20A. It is shown that for the rubber mixture 7-NO-68-1SK a partial replacement of carbon blacks P 803 on the schungite PSH-5 in an amount of 15 parts by weight leads to an improvement in the rheometric parameters, physico-mechanical and operational properties of vulcanizates. For the rubber mixture 81-453, partial replacement of the persil 175 on shungite PSH-5 also allows improving the rheometric properties and increasing the physico-mechanical and operational parameters.
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