Pub Date : 2019-02-22DOI: 10.17073/0021-3438-2019-1-16-24
E. Selivanov, S. Sergeeva, R. Gulyaeva
X-ray diffraction, optical microscopy and X-ray microanalysis were used to determine the composition and distribution of elements in the main mineral constituents of oxidized nickel ore at the Sakhalin deposit (goethite, hematite, serpentine, talc and chlorite). The main fraction of nickel is concentrated in iron oxides, where its content reaches 2,4 %, while in magnesium silicates it does not exceed 0,4 %. The sequence and temperature intervals of transformations were established when heating ore in inert and reducing media by means of thermal analysis methods combined with mass-spectrometric analysis of gases and subsequent X-ray phase analysis of products. The temperature regimes of ore roasting for the reduction of nickel and iron from their minerals were justified. The temperature regimes of sample heating are assumed to be close to the conditions implemented in industrial units (electric furnaces) where the rate of charge heating varies within 5—15 degrees/min, up to the melting point (1450 °С) of ferronickel and slag. It is proposed to use information on material composition, thermal properties and metal forms in ore to select regimes and technologies for their pyro-or hydrometallurgical processing. Nickel and iron recovery from oxides in CO environment occurs above 800 °С, while serpentines remain stable up to 1200 °С. The use of coke as a reducing agent allows reducing iron and nickel from serpentines at temperatures above 1250 °С. The obtained data were used to substantiate the operating conditions of roaster and electric furnaces during ferronickel smelting from oxidized ores. When roasting, resulting ferronickel particles will contain 2—4 % Ni. Completing recovery processes in the electric furnace will ensure metal recovery from magnesium silicates, which will slightly increase the nickel content in ferro-nickel.
{"title":"Phase composition and thermal properties of the Sakharinskoe deposit oxidized nickel ore","authors":"E. Selivanov, S. Sergeeva, R. Gulyaeva","doi":"10.17073/0021-3438-2019-1-16-24","DOIUrl":"https://doi.org/10.17073/0021-3438-2019-1-16-24","url":null,"abstract":"X-ray diffraction, optical microscopy and X-ray microanalysis were used to determine the composition and distribution of elements in the main mineral constituents of oxidized nickel ore at the Sakhalin deposit (goethite, hematite, serpentine, talc and chlorite). The main fraction of nickel is concentrated in iron oxides, where its content reaches 2,4 %, while in magnesium silicates it does not exceed 0,4 %. The sequence and temperature intervals of transformations were established when heating ore in inert and reducing media by means of thermal analysis methods combined with mass-spectrometric analysis of gases and subsequent X-ray phase analysis of products. The temperature regimes of ore roasting for the reduction of nickel and iron from their minerals were justified. The temperature regimes of sample heating are assumed to be close to the conditions implemented in industrial units (electric furnaces) where the rate of charge heating varies within 5—15 degrees/min, up to the melting point (1450 °С) of ferronickel and slag. It is proposed to use information on material composition, thermal properties and metal forms in ore to select regimes and technologies for their pyro-or hydrometallurgical processing. Nickel and iron recovery from oxides in CO environment occurs above 800 °С, while serpentines remain stable up to 1200 °С. The use of coke as a reducing agent allows reducing iron and nickel from serpentines at temperatures above 1250 °С. The obtained data were used to substantiate the operating conditions of roaster and electric furnaces during ferronickel smelting from oxidized ores. When roasting, resulting ferronickel particles will contain 2—4 % Ni. Completing recovery processes in the electric furnace will ensure metal recovery from magnesium silicates, which will slightly increase the nickel content in ferro-nickel.","PeriodicalId":14523,"journal":{"name":"Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73890400","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 : 2019-02-22DOI: 10.17073/0021-3438-2019-1-34-49
I. Komelin, A. P. Lysenko, D. S. Kondrat’eva
Corrosion tests of SCh15 cast iron, Steel 3 and Steel 3 with aluminized coating in some compositions of 10%MgCl2-KCl-NaCl and 10%MgCl2-KCl-Naa-Caa2 salt melts with 10 %, 25 % and 40 % CaCl2 concentrations, and also in 10MgCl2-45%KCl-20%NaCl-25%NaBr melt, and in the gas phase above these melts at 700 °C. A gravimetric method was used to determine corrosion rates of metal samples. Chemical analysis of absorption solutions was used to determine concentrations of halide and hydrogen halide impurities in air blown through the reactor with melts and samples. It was shown that carbon steel aluminizing can reduce the corrosion rate in the gas phase over the salt melt by a factor of 5 to 70. The formation mechanism of gases aggressive in relation to carbon steel and cast iron in atmospheric air in contact with salt chloride melt was considered. Accelerated hydrogen chloride and chlorine formation during the salt melt interaction with atmospheric air under the influence of iron corrosion products was found.
{"title":"Corrosion of carbon steel and cast iron in gas phase above salt melts used in magnesium industry","authors":"I. Komelin, A. P. Lysenko, D. S. Kondrat’eva","doi":"10.17073/0021-3438-2019-1-34-49","DOIUrl":"https://doi.org/10.17073/0021-3438-2019-1-34-49","url":null,"abstract":"Corrosion tests of SCh15 cast iron, Steel 3 and Steel 3 with aluminized coating in some compositions of 10%MgCl2-KCl-NaCl and 10%MgCl2-KCl-Naa-Caa2 salt melts with 10 %, 25 % and 40 % CaCl2 concentrations, and also in 10MgCl2-45%KCl-20%NaCl-25%NaBr melt, and in the gas phase above these melts at 700 °C. A gravimetric method was used to determine corrosion rates of metal samples. Chemical analysis of absorption solutions was used to determine concentrations of halide and hydrogen halide impurities in air blown through the reactor with melts and samples. It was shown that carbon steel aluminizing can reduce the corrosion rate in the gas phase over the salt melt by a factor of 5 to 70. The formation mechanism of gases aggressive in relation to carbon steel and cast iron in atmospheric air in contact with salt chloride melt was considered. Accelerated hydrogen chloride and chlorine formation during the salt melt interaction with atmospheric air under the influence of iron corrosion products was found.","PeriodicalId":14523,"journal":{"name":"Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90047548","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 : 2018-12-14DOI: 10.17073/0021-3438-2018-6-4-11
A. Valkov, L. Krylova
The paper covers experimental and theoretical studies of technical solutions for copper liquid extraction by organic extractants from sulfuric acid solutions that neutralize the negative effect of hydrogen ions released as a result of copper cations interaction with oximes on the copper extraction into the organic phase, and increase the technical and economic parameters of the process. In order to reduce the volume of processed solutions, copper extraction by the extractant solution in a diluent from the previously obtained thickened copper precipitate by sodium carbonate addition was studied. Subsequent operations for copper organic phase purification from metal impurities and re-extraction were carried out by methods known in liquid extraction. It was experimentally found that the use of copper pre-concentration in the precipitate makes it possible to increase the copper content in the extractant by 3—4 times to 1 g per 1 % (abs.) of the oxime content in the organic phase. It is required to maintain a ratio of 2 moles of oxime to 1 mole of copper in the precipitate to ensure rapid delamination and full extraction of copper. Dependencies of parameters were calculated for the stages of copper extraction from the thickened solution precipitate and extract washing. It was shown that extraction system parameters can be increased by using copper from the extractant emulsion solution obtained by mixing the oxime solution in a diluent and the aqueous solution of sodium carbonate. Based on the results of experiments, extractant emulsion with sodium carbonate added into the first stage of the extraction process makes it possible to significantly increase the copper distribution coefficient and saturate the extractant in terms of copper as much as possible. Maximum copper extraction from the solution is achieved at a molar ratio of carbonate and oxime in the emulsion equal to 1 : 2. The proposed technical solutions increase distribution coefficients and maximize the extractant working capacity during copper extraction. The lower volume of phases involved in extraction results in a substantially reduced number of extraction equipment and costs of raffinate purification from extractant and diluent destruction products. The proposed extraction methods can be used to extract copper from natural and technological sulfuric acid solutions, for example from mine waters and solutions generated when processing mineral raw materials and man-made waste.
{"title":"METHODS FOR COPPER EXTRACTION FROM PRECIPITATE AND USING OXIME MIXED WITH SODIUM CARBONATE","authors":"A. Valkov, L. Krylova","doi":"10.17073/0021-3438-2018-6-4-11","DOIUrl":"https://doi.org/10.17073/0021-3438-2018-6-4-11","url":null,"abstract":"The paper covers experimental and theoretical studies of technical solutions for copper liquid extraction by organic extractants from sulfuric acid solutions that neutralize the negative effect of hydrogen ions released as a result of copper cations interaction with oximes on the copper extraction into the organic phase, and increase the technical and economic parameters of the process. In order to reduce the volume of processed solutions, copper extraction by the extractant solution in a diluent from the previously obtained thickened copper precipitate by sodium carbonate addition was studied. Subsequent operations for copper organic phase purification from metal impurities and re-extraction were carried out by methods known in liquid extraction. It was experimentally found that the use of copper pre-concentration in the precipitate makes it possible to increase the copper content in the extractant by 3—4 times to 1 g per 1 % (abs.) of the oxime content in the organic phase. It is required to maintain a ratio of 2 moles of oxime to 1 mole of copper in the precipitate to ensure rapid delamination and full extraction of copper. Dependencies of parameters were calculated for the stages of copper extraction from the thickened solution precipitate and extract washing. It was shown that extraction system parameters can be increased by using copper from the extractant emulsion solution obtained by mixing the oxime solution in a diluent and the aqueous solution of sodium carbonate. Based on the results of experiments, extractant emulsion with sodium carbonate added into the first stage of the extraction process makes it possible to significantly increase the copper distribution coefficient and saturate the extractant in terms of copper as much as possible. Maximum copper extraction from the solution is achieved at a molar ratio of carbonate and oxime in the emulsion equal to 1 : 2. The proposed technical solutions increase distribution coefficients and maximize the extractant working capacity during copper extraction. The lower volume of phases involved in extraction results in a substantially reduced number of extraction equipment and costs of raffinate purification from extractant and diluent destruction products. The proposed extraction methods can be used to extract copper from natural and technological sulfuric acid solutions, for example from mine waters and solutions generated when processing mineral raw materials and man-made waste.","PeriodicalId":14523,"journal":{"name":"Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86815483","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 : 2018-12-14DOI: 10.17073/0021-3438-2018-6-58-71
K. Nikitin, A. V. Sokolov, V. I. Nikitin, N. V. D’yachkov
The studies of fractional, chemical and phase compositions of aluminum-containing slags of different origin found that slags are multi-component systems consisting of metal and non-metal parts. The non-metal part contains water-soluble and water-insoluble components. A practical scheme for recycling aluminum-containing slags was proposed in order to isolate the water-insoluble component to be further used a secondary refractory dusting material. It was found that the secondary refractory dusting material has a positive effect on the quality of refractory ceramic molds in investment casting and the surface finish of experimental aluminum castings. This material improves the strength of refractory ceramic molds by 9 times in comparison with silica sand molds and increases gas permeability by 15 % to 33 % in comparison with fused alumina and silica sand molds, respectively. The study covers the processes used to produce refractory ceramic molds based on the secondary refractory dusting material. The mechanism of interaction between dusting material particles and suspension is theoretically justified in terms of colloid chemistry. Negatively charged aluminum hydroxide micelles appear when ceramic mold layers are formed using the secondary refractory dusting material. Interaction between differently charged Al(OH)3 and SiO2 micelles makes secondary refractory dusting material particles come in close contact with each other. The theoretically justified processes of ceramic mold layer formation with the secondary refractory dusting material make it possible to explain the reduction in the surface roughness of castings made of AK9ch aluminum casting alloy using investment casting by 3.7 times compared with standard production processes.
{"title":"THE USE OF ALUMINUM SLAG RECYCLING PRODUCTS IN INVESTMENT CASTING TECHNOLOGIES","authors":"K. Nikitin, A. V. Sokolov, V. I. Nikitin, N. V. D’yachkov","doi":"10.17073/0021-3438-2018-6-58-71","DOIUrl":"https://doi.org/10.17073/0021-3438-2018-6-58-71","url":null,"abstract":"The studies of fractional, chemical and phase compositions of aluminum-containing slags of different origin found that slags are multi-component systems consisting of metal and non-metal parts. The non-metal part contains water-soluble and water-insoluble components. A practical scheme for recycling aluminum-containing slags was proposed in order to isolate the water-insoluble component to be further used a secondary refractory dusting material. It was found that the secondary refractory dusting material has a positive effect on the quality of refractory ceramic molds in investment casting and the surface finish of experimental aluminum castings. This material improves the strength of refractory ceramic molds by 9 times in comparison with silica sand molds and increases gas permeability by 15 % to 33 % in comparison with fused alumina and silica sand molds, respectively. The study covers the processes used to produce refractory ceramic molds based on the secondary refractory dusting material. The mechanism of interaction between dusting material particles and suspension is theoretically justified in terms of colloid chemistry. Negatively charged aluminum hydroxide micelles appear when ceramic mold layers are formed using the secondary refractory dusting material. Interaction between differently charged Al(OH)3 and SiO2 micelles makes secondary refractory dusting material particles come in close contact with each other. The theoretically justified processes of ceramic mold layer formation with the secondary refractory dusting material make it possible to explain the reduction in the surface roughness of castings made of AK9ch aluminum casting alloy using investment casting by 3.7 times compared with standard production processes.","PeriodicalId":14523,"journal":{"name":"Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77030008","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 : 2018-12-14DOI: 10.17073/0021-3438-2018-6-51-57
R. S. Syryamkin, Y. Gorbunov, S. Sidelnikov, A. Y. Otmahova
The analysis of scientific and technical literature and practical data made it possible to found that changes in casting parameters for ingots using different mold designs allows varying the degree of ingot grain structure refinement in a sufficiently wide range, which should be reflected in the conditions of aluminum alloy profile extrusion as well as physical and mechanical properties of these profiles. Therefore, the purpose of the research was to assess the influence of the degree of grain structure refinement for Alloy 6063 ingots on extrusion deformation and speed parameters and mechanical properties of profiles produced. The study used several batches of Alloy 6063 ingots 178 mm in diameter cast under industrial conditions, as well as profiles obtained by direct extrusion on a 18 MN horizontal hydraulic press subjected to quenching and aging. The grain size in homogenized ingots was estimated by light microscopy using the Olimpus optical microscope, and mechanical properties tests were carried out using the Inspect 20 kN-1 universal test machine. It was found that the initial grain size in the ingot structure exerts a significant influence both on ingot plasticity during extrusion, and on the final structure and mechanical properties of profile products made of aluminum alloys. Having analyzed the results obtained, we can conclude that the increase in strength characteristics of products extruded from ingots with a more refined structure is due to the fact that fine grains are retained in the structure of metal after its deformation, and cast metal plasticity increases with the degree of grain structure refinement in the ingot. This leads to the higher efficiency of profile product hardening and metal outflow rate during extrusion.
{"title":"STUDY INTO THE INFLUENCE OF THE GRAIN STRUCTURE REFINEMENT DEGREE OF ALLOY 6063 INGOTS ON THEIR PLASTICITY, EXTRUSION PARAMETERS AND PROPERTIES OF EXTRUDED PROFILES","authors":"R. S. Syryamkin, Y. Gorbunov, S. Sidelnikov, A. Y. Otmahova","doi":"10.17073/0021-3438-2018-6-51-57","DOIUrl":"https://doi.org/10.17073/0021-3438-2018-6-51-57","url":null,"abstract":"The analysis of scientific and technical literature and practical data made it possible to found that changes in casting parameters for ingots using different mold designs allows varying the degree of ingot grain structure refinement in a sufficiently wide range, which should be reflected in the conditions of aluminum alloy profile extrusion as well as physical and mechanical properties of these profiles. Therefore, the purpose of the research was to assess the influence of the degree of grain structure refinement for Alloy 6063 ingots on extrusion deformation and speed parameters and mechanical properties of profiles produced. The study used several batches of Alloy 6063 ingots 178 mm in diameter cast under industrial conditions, as well as profiles obtained by direct extrusion on a 18 MN horizontal hydraulic press subjected to quenching and aging. The grain size in homogenized ingots was estimated by light microscopy using the Olimpus optical microscope, and mechanical properties tests were carried out using the Inspect 20 kN-1 universal test machine. It was found that the initial grain size in the ingot structure exerts a significant influence both on ingot plasticity during extrusion, and on the final structure and mechanical properties of profile products made of aluminum alloys. Having analyzed the results obtained, we can conclude that the increase in strength characteristics of products extruded from ingots with a more refined structure is due to the fact that fine grains are retained in the structure of metal after its deformation, and cast metal plasticity increases with the degree of grain structure refinement in the ingot. This leads to the higher efficiency of profile product hardening and metal outflow rate during extrusion.","PeriodicalId":14523,"journal":{"name":"Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90231081","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 : 2018-12-14DOI: 10.17073/0021-3438-2018-6-42-50
M. M. Skripalenko, B. Romantsev, V. Bazhenov, B. Tran, M. N. Skripalenko, S. P. Galkin, M. B. Savonkin, Y. Gladkov
Mannesmann piercing of ingots, which were made of aluminum alloy by casting, was done using plugs of different shape: entire plug, plug with cavity and hollow plug. Plugs had same diameter of calibrating segment. Piercing was carried out at 400 °C ofbillets. Influence of plugs’ shape on variation of hollow shells’ diameter, wall thickness and density along their length was estimated. Hollow shells were cut into 15 equal rings to measure density using hydrostatic (Archimedean) weighing. Experimental operations were simulated using FEM computer software. Casting was simulated using ProCAST, piercing — using QForm. Variation of hollow shells’ diameter, wall thickness and density along their length was estimated after simulation had been done. Experimental and simulation data were compared to check FEM simulation accuracy. Difference between experiment and simulation for density was not more than 2 %, for hollow shells’ dimensions — 20 %. Conducted investigation allowed estimation of how plug’s shape affects hollow shells’ dimensions accuracy and density. It was established that hollow plug or plug with cavity, in terms of dimensions accuracy and density variation, are preferable for piercing. Each of plugs being used, provides manufacturing of hollow shells with maximum density for all volume except close to hollow shell’s edges domains, where density is 1 % less than maximum value.
{"title":"FEM SIMULATION OF MANNESMANN PIERCING OF ALUMINUM ALLOY INGOTS","authors":"M. M. Skripalenko, B. Romantsev, V. Bazhenov, B. Tran, M. N. Skripalenko, S. P. Galkin, M. B. Savonkin, Y. Gladkov","doi":"10.17073/0021-3438-2018-6-42-50","DOIUrl":"https://doi.org/10.17073/0021-3438-2018-6-42-50","url":null,"abstract":"Mannesmann piercing of ingots, which were made of aluminum alloy by casting, was done using plugs of different shape: entire plug, plug with cavity and hollow plug. Plugs had same diameter of calibrating segment. Piercing was carried out at 400 °C ofbillets. Influence of plugs’ shape on variation of hollow shells’ diameter, wall thickness and density along their length was estimated. Hollow shells were cut into 15 equal rings to measure density using hydrostatic (Archimedean) weighing. Experimental operations were simulated using FEM computer software. Casting was simulated using ProCAST, piercing — using QForm. Variation of hollow shells’ diameter, wall thickness and density along their length was estimated after simulation had been done. Experimental and simulation data were compared to check FEM simulation accuracy. Difference between experiment and simulation for density was not more than 2 %, for hollow shells’ dimensions — 20 %. Conducted investigation allowed estimation of how plug’s shape affects hollow shells’ dimensions accuracy and density. It was established that hollow plug or plug with cavity, in terms of dimensions accuracy and density variation, are preferable for piercing. Each of plugs being used, provides manufacturing of hollow shells with maximum density for all volume except close to hollow shell’s edges domains, where density is 1 % less than maximum value.","PeriodicalId":14523,"journal":{"name":"Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81576128","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 : 2018-12-13DOI: 10.17073/0021-3438-2018-6-31-41
V. Cherepov, A. Kropachev, O. N. Budin
The paper presents an overview of methods for obtaining perovskite structure titanates and doping them with rare-earth elements. The results of scientific research conducted by authors from different countries related to the study of the effect of doping perovskite structure titanates with rare-earth elements on their electromagnetic properties are discussed. The paper also comprises information on the use of perovskite structure titanates in various industries. As exemplified by barium titanate (BaTiO3), a comparative analysis of some morphological properties (particle size, structure) and electromagnetic characteristics (dielectric constant, Curie temperature, modulus of longitudinal oscillations (d33)) of powders obtained (and doped) by different methods is carried out. Techniques for various BaTiO3 preparation methods such as solvothermic, hydrothermal, sol-gel, chemical deposition, and solid-phase sintering are described. The paper provides the results of studies on the effect of changes in process parameters (temperature, pH, composition of the initial mixture of materials and concentration of reagents) on the phase, morphology and BaTiO3particle formation rate in hydrothermal synthesis (using BaCl2, TiCl4and NaOH as initial materials). In addition, experiments were conducted to study the effect of microwave radiation power in ВаСОз and ТЮ2 solid-phase sintering on the dielectric and ferroelectric properties of ВаТЮз ceramics. The analysis of methods for obtaining BaTiO3 and doping it with rare-earth elements found that at present the hydrothermal method and the method of solid-phase sintering (including with microwave radiation) can be regarded as advanced technologies for obtaining perovskite structure materials with predetermined properties.
{"title":"PROSPECTS FOR THE DEVELOPMENT OF METHODS FOR SYNTHESIZING PEROVSKITE STRUCTURE TITANATES AND DOPING THEM WITH RARE-EARTH ELEMENTS","authors":"V. Cherepov, A. Kropachev, O. N. Budin","doi":"10.17073/0021-3438-2018-6-31-41","DOIUrl":"https://doi.org/10.17073/0021-3438-2018-6-31-41","url":null,"abstract":"The paper presents an overview of methods for obtaining perovskite structure titanates and doping them with rare-earth elements. The results of scientific research conducted by authors from different countries related to the study of the effect of doping perovskite structure titanates with rare-earth elements on their electromagnetic properties are discussed. The paper also comprises information on the use of perovskite structure titanates in various industries. As exemplified by barium titanate (BaTiO3), a comparative analysis of some morphological properties (particle size, structure) and electromagnetic characteristics (dielectric constant, Curie temperature, modulus of longitudinal oscillations (d33)) of powders obtained (and doped) by different methods is carried out. Techniques for various BaTiO3 preparation methods such as solvothermic, hydrothermal, sol-gel, chemical deposition, and solid-phase sintering are described. The paper provides the results of studies on the effect of changes in process parameters (temperature, pH, composition of the initial mixture of materials and concentration of reagents) on the phase, morphology and BaTiO3particle formation rate in hydrothermal synthesis (using BaCl2, TiCl4and NaOH as initial materials). In addition, experiments were conducted to study the effect of microwave radiation power in ВаСОз and ТЮ2 solid-phase sintering on the dielectric and ferroelectric properties of ВаТЮз ceramics. The analysis of methods for obtaining BaTiO3 and doping it with rare-earth elements found that at present the hydrothermal method and the method of solid-phase sintering (including with microwave radiation) can be regarded as advanced technologies for obtaining perovskite structure materials with predetermined properties.","PeriodicalId":14523,"journal":{"name":"Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76486478","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 : 2018-12-13DOI: 10.17073/0021-3438-2018-6-12-19
S. Mamyachenkov, S. Yakornov, O. S. Anisimova, P. Kozlov, D. A. Ivakin
The effect that the main parameters of zinc electrolysis from an alkaline zincate solution have on current efficiency and power consumption was studied in laboratory conditions. Zinc concentration (initial and final), current density and temperature were chosen as variable parameters. The study used both model electrolytes (prepared using standard reagents) and real ones produced by leaching the calcined middling product obtained when processing zinc-bearing dusts of ferrous metallurgy. It was shown that the current efficiency of zinc can be quite high (more than 90 %) even at an initial zinc concentration in the alkaline electrolyte of 10 g/dm 3 . However, this requires low current loads (100—400 A/m 2 ) that are impractical in industrial electrolysis used to produce powdered metal, since the actual current density decreases as the cathode deposit surface develops and may fall below the limiting diffusion current of complex ions. In this case, the growth of enlarged dendrites is expected with the formation of «short-circuited» sections in the interelectrode space, which as a whole will reduce the zinc current efficiency. Larger-scale laboratory studies focused on zinc electrolysis from a real zincate solution made it possible to determine the most energy-efficient (with the highest zinc current efficiency and the lowest power consumption) process parameters: current density — 1000—2000 A/m 2 ; electrolyte temperature — 50—80 °С; initial zinc concentration — 20—50 g/dm 3 ; residual zinc concentration — not less than 15 g/dm 3 . These conditions will ensure high current efficiency (85 — 95 %) and electric power consumption (2,28—3,20 kW-h/kg Zn ). For the «depleted» zincate solution with a zinc content of 10 g/dm 3 , the highest current efficiency (more than 90 %) is achieved at a current density of 125 A/m 2 , close to the diffusion current density j = = 95,7 A/m 2 . With j > 500 A/m 2 , the current efficiency is significantly lower due to the intensive hydrogen release. A qualitative evaluation of the resulting cathode deposit was made (by the visible dimensions of crystals) in studies on an enlarged electrolytic cell.
{"title":"RESEARCH OF THE INFLUENCE OF TECHNOLOGICAL PARAMETERS ON EFFICIENCY OF ZINC ELECTROLYSIS FROM ALKALINE SOLUTIONS","authors":"S. Mamyachenkov, S. Yakornov, O. S. Anisimova, P. Kozlov, D. A. Ivakin","doi":"10.17073/0021-3438-2018-6-12-19","DOIUrl":"https://doi.org/10.17073/0021-3438-2018-6-12-19","url":null,"abstract":"The effect that the main parameters of zinc electrolysis from an alkaline zincate solution have on current efficiency and power consumption was studied in laboratory conditions. Zinc concentration (initial and final), current density and temperature were chosen as variable parameters. The study used both model electrolytes (prepared using standard reagents) and real ones produced by leaching the calcined middling product obtained when processing zinc-bearing dusts of ferrous metallurgy. It was shown that the current efficiency of zinc can be quite high (more than 90 %) even at an initial zinc concentration in the alkaline electrolyte of 10 g/dm 3 . However, this requires low current loads (100—400 A/m 2 ) that are impractical in industrial electrolysis used to produce powdered metal, since the actual current density decreases as the cathode deposit surface develops and may fall below the limiting diffusion current of complex ions. In this case, the growth of enlarged dendrites is expected with the formation of «short-circuited» sections in the interelectrode space, which as a whole will reduce the zinc current efficiency. Larger-scale laboratory studies focused on zinc electrolysis from a real zincate solution made it possible to determine the most energy-efficient (with the highest zinc current efficiency and the lowest power consumption) process parameters: current density — 1000—2000 A/m 2 ; electrolyte temperature — 50—80 °С; initial zinc concentration — 20—50 g/dm 3 ; residual zinc concentration — not less than 15 g/dm 3 . These conditions will ensure high current efficiency (85 — 95 %) and electric power consumption (2,28—3,20 kW-h/kg Zn ). For the «depleted» zincate solution with a zinc content of 10 g/dm 3 , the highest current efficiency (more than 90 %) is achieved at a current density of 125 A/m 2 , close to the diffusion current density j = = 95,7 A/m 2 . With j > 500 A/m 2 , the current efficiency is significantly lower due to the intensive hydrogen release. A qualitative evaluation of the resulting cathode deposit was made (by the visible dimensions of crystals) in studies on an enlarged electrolytic cell.","PeriodicalId":14523,"journal":{"name":"Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81239715","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 : 2018-12-13DOI: 10.17073/0021-3438-2018-6-20-30
A. A. Korolev, G. Maltsev, K. Timofeev, V. G. Lobanov
The paper relevance is determined by the need to create an environmentally safe, high-performance and cost-efficient integrated vacuum distillation technology for the processing of lead-containing middling products and wastes, in particular, a Sb-Pb-Ag (SPA) alloy resulting from the recovery of silicate slag from copper anode slime melting to obtain sellable mono-element concentrates of antimony, lead and silver. Laboratory studies were carried out on SPA alloy processing with the calculations of «T—x» temperature-composition VLE (vapor liquid equilibrium) diagrams to analyze the behavior of Sb-Pb and Pb-Ag binary alloys during processing, select preliminary system temperature and pressure, and assess component separation efficiency in the following conditions: T = = 900+2100 K, P = 1+133 Pa, т = 8+16 hours. The aim of the study was to investigate the effect of temperature and pressure in the system, the duration of sublimation on the completeness of extraction and the degree of antimony, lead and silver separation from the SPA composition. Activity coefficients of binary alloy components when constructing VLE diagrams were calculated using the MI- VM (molecular interaction volume model). The information is obtained regarding the effect of temperature and vacuum level on the degree of sublimation and separation of metals from Sb—Pb and Pb—Ag compositions of different contents. Saturated vapor pressures were calculated for Sb (p* = 273.664+ 67436.9 Pa), Pb (0.149+485.9), Ag (5.05440 -5 -6.558) at T = 1073+1773 K. It was demonstrated that the high values of the pSb /PPb = 1832.98+138.79, рр ь /pA g = 2948.16+74.09 ratio and lgPsb = 2.099+3.33 and lgPp b = 1.813+ +3.944 separation factor create theoretical prerequisites for a selective isolation of these metals by vacuum distillation, when antimony and lead are successively enriched in the gas phase (Ps^ > 1, Pp b > 1), and silver — in the liquid phase. The molar fraction of hard-to-sublimate lead/silver in the gaseous phase ур Ь /уA g = (1.55+982)T0 -3 /(36+772)T0 -3 is increased with rising temperature 894+1601/1399+2099 K, pressure 1.33+133 Pa and metal content in the alloy x Pb /x Ag = 0.9+0.9999/0.9+0.99. The MIVM model was used to calculate the activity factors of antimony Ysb = 0.832+0.999, lead yp b = 0.474+1.0, YA g = 0.331+0.999 for Sb/Pb and Pb/Ag alloys with the following composition 0.1+0.9/0.9+0.1 in the investigated temperature range. The found dependences of the amount and composition of polymetallic alloy sublimation products on the process parameters are important for practical application due to the development of a principal technology for SPA processing by vacuum distillation.
本文的相关性取决于需要创造一种环境安全、高性能和成本效益高的综合真空蒸馏技术，用于处理含铅中间产品和废物，特别是从铜阳极泥熔化中回收硅酸盐渣，以获得可销售的锑、铅和银的单元素精矿，从而产生一种Sb-Pb-Ag (SPA)合金。通过计算«T - x»温度-成分VLE(汽液平衡)图对SPA合金的加工进行了实验室研究，分析了Sb-Pb和Pb-Ag二元合金在加工过程中的行为，选择了初步的系统温度和压力，并评估了在以下条件下的组分分离效率:T = = 900+2100 K, P = 1+133 Pa, et = 8+16 h。本研究的目的是研究系统中的温度和压力、升华时间对萃取的完整性以及锑、铅和银从SPA成分中分离的程度的影响。采用MI- VM(分子相互作用体积模型)计算了二元合金组分在构建VLE图时的活度系数。得到了温度和真空度对不同含量的锑铅和铅银组合物升华和金属分离程度的影响。在T = 1073+1773 K时，计算了Sb (p* = 273.664+ 67436.9 Pa)、Pb(0.149+485.9)、Ag(5.05440 -5 -6.558)的饱和蒸汽压。结果表明，当锑和铅在气相(Ps^ > 1, Pp b > 1)和液相中依次富集时，pSb /PPb = 1832.98+138.79, r /pA g = 2948.16+74.09, lgPsb = 2.099+3.33和lgppb = 1.813+ +3.944的高分离系数为真空蒸馏选择性分离这些金属创造了理论前提。随着温度(894+1601/1399+2099 K)、压力(1.33+133 Pa)和合金中金属含量(x Pb /x Ag = 0.9+0.9999/0.9+0.99)的升高，气相中难以升华的铅/银的摩尔分数ур Ь /уA g = (1.55+982)T0 -3 /(36+772)T0 -3增大。采用MIVM模型计算了0.1+0.9/0.9+0.1组成的Sb/Pb和Pb/Ag合金在研究温度范围内，锑Ysb = 0.832+0.999，铅yp b = 0.474+1.0, YA g = 0.331+0.999的活度因子。多金属合金升华产物的数量和成分与工艺参数的关系对实际应用具有重要意义，这是由于真空蒸馏加工SPA的主要技术的发展。
{"title":"SB-PB-AG ALLOY PROCESSING BY VACUUM DISTILLATION","authors":"A. A. Korolev, G. Maltsev, K. Timofeev, V. G. Lobanov","doi":"10.17073/0021-3438-2018-6-20-30","DOIUrl":"https://doi.org/10.17073/0021-3438-2018-6-20-30","url":null,"abstract":"The paper relevance is determined by the need to create an environmentally safe, high-performance and cost-efficient integrated vacuum distillation technology for the processing of lead-containing middling products and wastes, in particular, a Sb-Pb-Ag (SPA) alloy resulting from the recovery of silicate slag from copper anode slime melting to obtain sellable mono-element concentrates of antimony, lead and silver. Laboratory studies were carried out on SPA alloy processing with the calculations of «T—x» temperature-composition VLE (vapor liquid equilibrium) diagrams to analyze the behavior of Sb-Pb and Pb-Ag binary alloys during processing, select preliminary system temperature and pressure, and assess component separation efficiency in the following conditions: T = = 900+2100 K, P = 1+133 Pa, т = 8+16 hours. The aim of the study was to investigate the effect of temperature and pressure in the system, the duration of sublimation on the completeness of extraction and the degree of antimony, lead and silver separation from the SPA composition. Activity coefficients of binary alloy components when constructing VLE diagrams were calculated using the MI- VM (molecular interaction volume model). The information is obtained regarding the effect of temperature and vacuum level on the degree of sublimation and separation of metals from Sb—Pb and Pb—Ag compositions of different contents. Saturated vapor pressures were calculated for Sb (p* = 273.664+ 67436.9 Pa), Pb (0.149+485.9), Ag (5.05440 -5 -6.558) at T = 1073+1773 K. It was demonstrated that the high values of the pSb /PPb = 1832.98+138.79, рр ь /pA g = 2948.16+74.09 ratio and lgPsb = 2.099+3.33 and lgPp b = 1.813+ +3.944 separation factor create theoretical prerequisites for a selective isolation of these metals by vacuum distillation, when antimony and lead are successively enriched in the gas phase (Ps^ > 1, Pp b > 1), and silver — in the liquid phase. The molar fraction of hard-to-sublimate lead/silver in the gaseous phase ур Ь /уA g = (1.55+982)T0 -3 /(36+772)T0 -3 is increased with rising temperature 894+1601/1399+2099 K, pressure 1.33+133 Pa and metal content in the alloy x Pb /x Ag = 0.9+0.9999/0.9+0.99. The MIVM model was used to calculate the activity factors of antimony Ysb = 0.832+0.999, lead yp b = 0.474+1.0, YA g = 0.331+0.999 for Sb/Pb and Pb/Ag alloys with the following composition 0.1+0.9/0.9+0.1 in the investigated temperature range. The found dependences of the amount and composition of polymetallic alloy sublimation products on the process parameters are important for practical application due to the development of a principal technology for SPA processing by vacuum distillation.","PeriodicalId":14523,"journal":{"name":"Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83591136","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}
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