Pub Date : 2018-10-13DOI: 10.17073/0021-3438-2018-5-16-22
O. V. Nechvoglod, S. Sergeeva, K. Pikulin, E. Selivanov
The paper justifies the method of processing sulfide-metal melts including their granulation and subsequent electrolysis of granules. High-speed crystallization ensures ultrafine structure formation and stabilizes non-stoichiometric high-temperature phases leading to an increase in the reactivity of granules during subsequent hydrometallurgical processing. Copper powder was isolated at the cathode, and sulfur-sulfide slime (NiS–Сu9S5–Cu7S4–S) was isolated at the anode in a sulfuric acid solution during the electrolysis of granular copper-nickel matte (Cu : Ni = 1 : 1). The influence of current density and process duration on electrolysis parameters and the quality of copper powder isolated was estimated. Sulfur sulfide slime (containing more than 50 % sulfur) forms a passivation layer on granule surfaces, which prevents reagent feeding and reaction product removal from the interaction zone. Anodic current density of up to 100 A/m2 ensures metal conversion into a solution and copper powder (PMS-1 grade) formation at the cathode. Powder is represented by 1 to 100 μm particles of dendritic and fragmented shapes. High-quality copper powder isolation was achieved when saturating electrolyte with nickel to 28,0 g/dm3 . In this case, anode efficiency was 37 % with respect to sulfur, and cathode efficiency was 92,8 % for copper. The process is recommended for copper and nickel separation when processing sulfide-metal alloys. Copper content of in the solution during electrolysis ranged from 0,4 to 2,0 g/dm3.
{"title":"ELECTROLYSIS OF GRANULATED COPPER-NICKEL MATTE","authors":"O. V. Nechvoglod, S. Sergeeva, K. Pikulin, E. Selivanov","doi":"10.17073/0021-3438-2018-5-16-22","DOIUrl":"https://doi.org/10.17073/0021-3438-2018-5-16-22","url":null,"abstract":"The paper justifies the method of processing sulfide-metal melts including their granulation and subsequent electrolysis of granules. High-speed crystallization ensures ultrafine structure formation and stabilizes non-stoichiometric high-temperature phases leading to an increase in the reactivity of granules during subsequent hydrometallurgical processing. Copper powder was isolated at the cathode, and sulfur-sulfide slime (NiS–Сu9S5–Cu7S4–S) was isolated at the anode in a sulfuric acid solution during the electrolysis of granular copper-nickel matte (Cu : Ni = 1 : 1). The influence of current density and process duration on electrolysis parameters and the quality of copper powder isolated was estimated. Sulfur sulfide slime (containing more than 50 % sulfur) forms a passivation layer on granule surfaces, which prevents reagent feeding and reaction product removal from the interaction zone. Anodic current density of up to 100 A/m2 ensures metal conversion into a solution and copper powder (PMS-1 grade) formation at the cathode. Powder is represented by 1 to 100 μm particles of dendritic and fragmented shapes. High-quality copper powder isolation was achieved when saturating electrolyte with nickel to 28,0 g/dm3 . In this case, anode efficiency was 37 % with respect to sulfur, and cathode efficiency was 92,8 % for copper. The process is recommended for copper and nickel separation when processing sulfide-metal alloys. Copper content of in the solution during electrolysis ranged from 0,4 to 2,0 g/dm3.","PeriodicalId":14523,"journal":{"name":"Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78248014","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 : 2018-10-13DOI: 10.17073/0021-3438-2018-5-72
A. Editorial
.
．
{"title":"TO THE 100TH ANNIVERSARY OF THE BIRTH OF SERGEI IVANOVICH KUZNETSOV","authors":"A. Editorial","doi":"10.17073/0021-3438-2018-5-72","DOIUrl":"https://doi.org/10.17073/0021-3438-2018-5-72","url":null,"abstract":"<jats:p>.</jats:p>","PeriodicalId":14523,"journal":{"name":"Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy","volume":"53 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84863547","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 : 2018-10-13DOI: 10.17073/0021-3438-2018-5-48-55
V. Kargin, A. Y. Deryabin
The direct extrusion of large 7075 alloy bars 188, 214, 252, 283, 326, 560 mm in diameter was simulated with 0 and 0,5 friction coefficients, 80° and 90° die cone angles from the 800 mm diameter container at the 200 MN press using the DEFORM-2D software package. It provided the distribution of metal flow radial velocities on the dummy block working surface versus the contact friction value, die cone angle and extrusion ratio factor at the main and final stages of extrusion. Butt-end height at the beginning of back-end extrusion defect formation was taken equal to a distance between the dummy block plane and the plane of extruded metal feeding into flat or cone die openings. The joint effect of the extrusion ratio factor, friction coefficient and die cone angle on the butt-end height, extrusion force, deformation and stress intensity factors, and die opening edge temperature was studied. Numerical experiments were performed based on the 23 complete factorial design for the following parameter variability intervals: Х1 = 3÷9, Х2 = 0÷0,5, Х3 = 80÷90°. Friction between the tool and the blank at the final extrusion stage has a negative effect due to a noticeable radial velocity reduction. This leads to the earlier initiation of central back-end extrusion defect formation. Extrusion into the conical die and increasing the extrusion ratio factor, on the contrary, speeds up radial flow velocity and ensures that the back-end extrusion defect starts forming later. The main factor that determines butt-end height is the extrusion ratio factor. A mathematical model is proposed to select the butt-end thickness for specific conditions of extruding large bars with low extrusion ratios.
{"title":"SIMULATION OF FINAL DIRECT EXTRUSION STAGE FOR LARGE RODS WITH LOW EXTRUSION RATIO","authors":"V. Kargin, A. Y. Deryabin","doi":"10.17073/0021-3438-2018-5-48-55","DOIUrl":"https://doi.org/10.17073/0021-3438-2018-5-48-55","url":null,"abstract":"The direct extrusion of large 7075 alloy bars 188, 214, 252, 283, 326, 560 mm in diameter was simulated with 0 and 0,5 friction coefficients, 80° and 90° die cone angles from the 800 mm diameter container at the 200 MN press using the DEFORM-2D software package. It provided the distribution of metal flow radial velocities on the dummy block working surface versus the contact friction value, die cone angle and extrusion ratio factor at the main and final stages of extrusion. Butt-end height at the beginning of back-end extrusion defect formation was taken equal to a distance between the dummy block plane and the plane of extruded metal feeding into flat or cone die openings. The joint effect of the extrusion ratio factor, friction coefficient and die cone angle on the butt-end height, extrusion force, deformation and stress intensity factors, and die opening edge temperature was studied. Numerical experiments were performed based on the 23 complete factorial design for the following parameter variability intervals: Х1 = 3÷9, Х2 = 0÷0,5, Х3 = 80÷90°. Friction between the tool and the blank at the final extrusion stage has a negative effect due to a noticeable radial velocity reduction. This leads to the earlier initiation of central back-end extrusion defect formation. Extrusion into the conical die and increasing the extrusion ratio factor, on the contrary, speeds up radial flow velocity and ensures that the back-end extrusion defect starts forming later. The main factor that determines butt-end height is the extrusion ratio factor. A mathematical model is proposed to select the butt-end thickness for specific conditions of extruding large bars with low extrusion ratios.","PeriodicalId":14523,"journal":{"name":"Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy","volume":"50 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74295247","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 : 2018-10-13DOI: 10.17073/0021-3438-2018-5-56-65
E. Chernyshov, A. Romanov, V. V. Mylnikov
The article describes a study into the large-scale effect and properties of surface layers of solids in case of the Al–Mg system (AMg2) aluminum alloy. It demonstrates the dependence of surface layer properties on the absolute sizes of bodies. The conclusions obtained can be extended to studying the influence of different shapes of solids on their surface and linear bulk properties. New technology development and technological advance constantly toughen metal consumption requirements of engineering devices thus making it rather difficult to avoid fatigue striations and cracks forming in critical parts. In certain cases they may form at the earliest stages of operation, i.e. parts run with cracks most of their life cycle. Therefore, comprehensive assessment of their performance and life requires reliable data on the evolution of cyclic strength and durability parameters, and maximum information on the process of damage accumulation at all stages of fatigue loading: stages of crack origin and development leading to structural failure. Therefore, the need to improve the methods of fatigue testing and failure pattern detection is one of the most relevant problems of technical advance. It is established that the difference in deformation at a surface leads to changes in work-hardenability that involves changes in surface damageability and strength performance of samples. An approach to the large-scale effect as a phenomenon is considered from the perspective of the difference in surface layer plastic deformation for samples of different absolute sizes.
{"title":"SOME ASPECTS OF INFLUENCE EXERTED BY LARGE-SCALE EFFECT NATURE AT CYCLIC TESTS ON OPERATION AND RELIABILITY OF ALUMINUM ALLOY PRODUCTS","authors":"E. Chernyshov, A. Romanov, V. V. Mylnikov","doi":"10.17073/0021-3438-2018-5-56-65","DOIUrl":"https://doi.org/10.17073/0021-3438-2018-5-56-65","url":null,"abstract":"The article describes a study into the large-scale effect and properties of surface layers of solids in case of the Al–Mg system (AMg2) aluminum alloy. It demonstrates the dependence of surface layer properties on the absolute sizes of bodies. The conclusions obtained can be extended to studying the influence of different shapes of solids on their surface and linear bulk properties. New technology development and technological advance constantly toughen metal consumption requirements of engineering devices thus making it rather difficult to avoid fatigue striations and cracks forming in critical parts. In certain cases they may form at the earliest stages of operation, i.e. parts run with cracks most of their life cycle. Therefore, comprehensive assessment of their performance and life requires reliable data on the evolution of cyclic strength and durability parameters, and maximum information on the process of damage accumulation at all stages of fatigue loading: stages of crack origin and development leading to structural failure. Therefore, the need to improve the methods of fatigue testing and failure pattern detection is one of the most relevant problems of technical advance. It is established that the difference in deformation at a surface leads to changes in work-hardenability that involves changes in surface damageability and strength performance of samples. An approach to the large-scale effect as a phenomenon is considered from the perspective of the difference in surface layer plastic deformation for samples of different absolute sizes.","PeriodicalId":14523,"journal":{"name":"Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85136678","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 : 2018-10-13DOI: 10.17073/0021-3438-2018-5-31-38
A. Petrova, V. Bazhenov, A. Koltygin
Prediction of the misrun formation in thin-walled castings of magnesium alloys is a crucial task for foundry. The computer simulation of the casting processes can be used to solve this problem. A reasonable simulation results requires the correct thermal properties of the alloy and the mold over a wide range of temperatures and the value of interfacial heat transfer coefficient between the casting and the mold, and the critical solid fraction at which the alloy flow in the mold is choked off. In this paper we determine the interfacial heat transfer coefficient between the magnesium alloy ML5 (AZ91) and the sand mold with a furan binder. It was done by the comparing the simulated spiral test lengths with the experimental spiral test lengths obtained under the same conditions. Above the liquidus temperature the interfacial heat transfer coefficient IHTCL = 1500 W/(m2 ·K) at pouring temperatures 670 and 740 °С and IHTCL = 1800 W/(m2 ·K) at pouring temperature 810 °С. Below the solidus temperature the interfacial heat transfer coefficient IHTCS = 600 W/(m2 ·K). We also determined the critical solid fraction of ML5 (AZ91) magnesium alloy for the casting made in the furan bonded sand mold (at a cooling rate ~2 K/s) and it was 0.1–0.15. We compared the simulated misruns position and the experimental misrun position in the «Protective cup» casting produced from the ML5 (AZ91) alloy into the sand mold with furan binder. The value of the critical solid fraction was clarified. The castings were made at pouring temperatures 630 and 670 °C, and the critical solid fraction was 0.1 in both cases.
{"title":"PREDICTION OF AZ91 CASTING MISRUNS AND ALLOY FLUIDITY USING NUMERICAL SIMULATION","authors":"A. Petrova, V. Bazhenov, A. Koltygin","doi":"10.17073/0021-3438-2018-5-31-38","DOIUrl":"https://doi.org/10.17073/0021-3438-2018-5-31-38","url":null,"abstract":"Prediction of the misrun formation in thin-walled castings of magnesium alloys is a crucial task for foundry. The computer simulation of the casting processes can be used to solve this problem. A reasonable simulation results requires the correct thermal properties of the alloy and the mold over a wide range of temperatures and the value of interfacial heat transfer coefficient between the casting and the mold, and the critical solid fraction at which the alloy flow in the mold is choked off. In this paper we determine the interfacial heat transfer coefficient between the magnesium alloy ML5 (AZ91) and the sand mold with a furan binder. It was done by the comparing the simulated spiral test lengths with the experimental spiral test lengths obtained under the same conditions. Above the liquidus temperature the interfacial heat transfer coefficient IHTCL = 1500 W/(m2 ·K) at pouring temperatures 670 and 740 °С and IHTCL = 1800 W/(m2 ·K) at pouring temperature 810 °С. Below the solidus temperature the interfacial heat transfer coefficient IHTCS = 600 W/(m2 ·K). We also determined the critical solid fraction of ML5 (AZ91) magnesium alloy for the casting made in the furan bonded sand mold (at a cooling rate ~2 K/s) and it was 0.1–0.15. We compared the simulated misruns position and the experimental misrun position in the «Protective cup» casting produced from the ML5 (AZ91) alloy into the sand mold with furan binder. The value of the critical solid fraction was clarified. The castings were made at pouring temperatures 630 and 670 °C, and the critical solid fraction was 0.1 in both cases.","PeriodicalId":14523,"journal":{"name":"Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy","volume":"54 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80410990","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 : 2018-10-13DOI: 10.17073/0021-3438-2018-5-66-71
A. Churyumov, V. V. Spasenko, D. M. Hazhina, A. Mikhaylovskaya, A. Solonin, A. Prosviryakov
This paper studies Ti–3,5Fe–4Cu–0,2B two-phase titanium alloy behavior during its thermal deformation processing under uniaxial compression. Boron was added to obtain a fine-grained structure in the cast state. Samples of alloys 6 mm in diameter were obtained by melting pure components in a vacuum induction furnace with their subsequent crystallization into a solid copper mold. Uniaxial compression tests with a true strain of 0,9 were performed using the Gleeble 3800 thermal-mechanical physical simulation system at 750, 800 and 900 °C and strain rates of 0,1; 1 and 10 s–1. Scanning electron microscopy was used to study the microstructure of the alloy in its initial and deformed states. A model of flow stress dependence on temperature and strain rate was built as a result of the tests. It is shown that pressure treatment involves recrystallization of the initial cast structure containing solid solutions based on α-Ti, β-Ti and titanium diboride aggregates. During the deformation process, the volume fraction of α-titanium solid solution grains decreases with rising temperature, and the fraction of the β phase, on the contrary, increases. In this case, the average grain size of solid solutions based on α-Ti and β-Ti varies insignificantly after deformation in almost all of the studied modes. It is shown that the preferred mode of hot pressure treatment for obtaining a high complex of mechanical properties in the investigated alloy is a temperature range of 750– 800 °C, since α-phase grain sizes increase from 2,2 to 4,5 μm with an increase in temperature to 900 °C.
{"title":"STUDY INTO STRUCTURAL EVOLUTION OF TWO-PHASE TITANIUM ALLOY DURING THERMAL DEFORMATION PROCESSING","authors":"A. Churyumov, V. V. Spasenko, D. M. Hazhina, A. Mikhaylovskaya, A. Solonin, A. Prosviryakov","doi":"10.17073/0021-3438-2018-5-66-71","DOIUrl":"https://doi.org/10.17073/0021-3438-2018-5-66-71","url":null,"abstract":"This paper studies Ti–3,5Fe–4Cu–0,2B two-phase titanium alloy behavior during its thermal deformation processing under uniaxial compression. Boron was added to obtain a fine-grained structure in the cast state. Samples of alloys 6 mm in diameter were obtained by melting pure components in a vacuum induction furnace with their subsequent crystallization into a solid copper mold. Uniaxial compression tests with a true strain of 0,9 were performed using the Gleeble 3800 thermal-mechanical physical simulation system at 750, 800 and 900 °C and strain rates of 0,1; 1 and 10 s–1. Scanning electron microscopy was used to study the microstructure of the alloy in its initial and deformed states. A model of flow stress dependence on temperature and strain rate was built as a result of the tests. It is shown that pressure treatment involves recrystallization of the initial cast structure containing solid solutions based on α-Ti, β-Ti and titanium diboride aggregates. During the deformation process, the volume fraction of α-titanium solid solution grains decreases with rising temperature, and the fraction of the β phase, on the contrary, increases. In this case, the average grain size of solid solutions based on α-Ti and β-Ti varies insignificantly after deformation in almost all of the studied modes. It is shown that the preferred mode of hot pressure treatment for obtaining a high complex of mechanical properties in the investigated alloy is a temperature range of 750– 800 °C, since α-phase grain sizes increase from 2,2 to 4,5 μm with an increase in temperature to 900 °C.","PeriodicalId":14523,"journal":{"name":"Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87039292","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 : 2018-10-12DOI: 10.17073/0021-3438-2018-5-4-15
V. I. Melik-Gaikazyan, N. P. Emel’yanova, D. V. Dolzhenkov
Spreading curves (SCs) are calculated for bubble diameters (de) 1 mm and 1 μm on substrates with different wettability: from maximumhydrophobicity (Г) to maximum-hydrophilicity (Ф) as well as incompletely wettable (Нх) ones, where x = 0,8; 0,6; 0,4 and 0,2 is the fraction of an ionized collector monolayer under the bubble. The calculations were based on the results of a numerical solution of the Laplace equation in the form of 12-figure tables such as Bashforth and Adams tables. They demonstrate firstly that the SCs obtained are identical to those calculated for bubbles with de = 20 and 10 nm, and thus SC shapes are unchanged in the 105 range, i.e. virtually for all flotation bubbles, and secondly that SC shapes and their mutual arrangement depend on substrate wettability. Spreading curves clearly illustrate the advantages of substrate Г adhesion to the bubble in comparison with substrate Ф, and for Нх an advantage of the substrate with a larger fraction of x. It is quantitatively shown that even with small spreading of nanobubbles adhered to the particle, their adherence force increases billion times so that large bubbles can fix on their increased perimeters and lead the particle to flotation. If, however, the adhesion of large bubbles to nanobubbles occurs before spreading of the latter, they will come off together, and the particle will not float. This mechanism was used for particle flotation in the processes of the Bessel brothers, Potter-Delpra and two processes of F. Elmor in the late 19th and early 20th centuries. The prospect of increasing the productivity and cost-efficiency of modern froth flotation by activating particle flotation not only with nanobubbles but also with larger bubbles is considered.
{"title":"EFFECT OF CAPILLARY PRESSURE IN NANOBUBBLES ON THEIR ADHERENCE TO PARTICLES DURING FROTH FLOATATION. PART 6. INFORMATIVITY OF BUBBLE SPREADING CURVES","authors":"V. I. Melik-Gaikazyan, N. P. Emel’yanova, D. V. Dolzhenkov","doi":"10.17073/0021-3438-2018-5-4-15","DOIUrl":"https://doi.org/10.17073/0021-3438-2018-5-4-15","url":null,"abstract":"Spreading curves (SCs) are calculated for bubble diameters (de) 1 mm and 1 μm on substrates with different wettability: from maximumhydrophobicity (Г) to maximum-hydrophilicity (Ф) as well as incompletely wettable (Нх) ones, where x = 0,8; 0,6; 0,4 and 0,2 is the fraction of an ionized collector monolayer under the bubble. The calculations were based on the results of a numerical solution of the Laplace equation in the form of 12-figure tables such as Bashforth and Adams tables. They demonstrate firstly that the SCs obtained are identical to those calculated for bubbles with de = 20 and 10 nm, and thus SC shapes are unchanged in the 105 range, i.e. virtually for all flotation bubbles, and secondly that SC shapes and their mutual arrangement depend on substrate wettability. Spreading curves clearly illustrate the advantages of substrate Г adhesion to the bubble in comparison with substrate Ф, and for Нх an advantage of the substrate with a larger fraction of x. It is quantitatively shown that even with small spreading of nanobubbles adhered to the particle, their adherence force increases billion times so that large bubbles can fix on their increased perimeters and lead the particle to flotation. If, however, the adhesion of large bubbles to nanobubbles occurs before spreading of the latter, they will come off together, and the particle will not float. This mechanism was used for particle flotation in the processes of the Bessel brothers, Potter-Delpra and two processes of F. Elmor in the late 19th and early 20th centuries. The prospect of increasing the productivity and cost-efficiency of modern froth flotation by activating particle flotation not only with nanobubbles but also with larger bubbles is considered.","PeriodicalId":14523,"journal":{"name":"Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90079601","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 : 2018-10-12DOI: 10.17073/0021-3438-2018-5-23-30
O. N. Budin, A. Kropachev, D. G. Agafonov, V. V. Сherepov
The article states the advantages of carbothermic perovskite concentrate decomposition in comparison with hydrometallurgical methods. The papers using the carbothermic method are noted. The paper provides information on existing perovskite processing methods that found no industrial application. The results obtained when studying titanium raw material decomposition in case of CaO·TiO2 artificially synthesized perovskite are given. Artificial perovskite was synthesized in a muffle furnace where a mixture of oxides (CaO = 41,2 wt.% and TiO2 = 58,8 wt.%) was premixed for 15 minutes and then briquetted into pellets using a 15 mm steel mold on a 147 МPa hydraulic press. The temperature of CaTiO3 synthesis was 1300 °C with a holding time of 4 hours. Experiments with a different carbon excess (20 and 30 wt.% of the content stoichiometrically required to recover perovskite components) were carried out. The carbothermic process of artificial perovskite decomposition (4 g pellets) was carried out in a vacuum furnace with a graphite heater in two stages: at 1500 °C, 1 hour holding time and 10,1 kPa residual pressure in an argon atmosphere at the first stage, and at t = 1750 °C, τ = 1 h, 1,3 Pa residual chamber pressure at the second one. Reaction products were studied by X-ray diffraction analysis on the «D8 Advance Bruker AXS» diffractometer. Experimental results demonstrated the practical possibility of titanium and calcium extraction from perovskite using the carbothermic method.
{"title":"STUDY INTO CARBOTHERMIC METHOD OF TITANIUM RAW MATERIAL DECOMPOSITION IN CASE OF ARTIFICIALLY SYNTHESIZED PEROVSKITE","authors":"O. N. Budin, A. Kropachev, D. G. Agafonov, V. V. Сherepov","doi":"10.17073/0021-3438-2018-5-23-30","DOIUrl":"https://doi.org/10.17073/0021-3438-2018-5-23-30","url":null,"abstract":"The article states the advantages of carbothermic perovskite concentrate decomposition in comparison with hydrometallurgical methods. The papers using the carbothermic method are noted. The paper provides information on existing perovskite processing methods that found no industrial application. The results obtained when studying titanium raw material decomposition in case of CaO·TiO2 artificially synthesized perovskite are given. Artificial perovskite was synthesized in a muffle furnace where a mixture of oxides (CaO = 41,2 wt.% and TiO2 = 58,8 wt.%) was premixed for 15 minutes and then briquetted into pellets using a 15 mm steel mold on a 147 МPa hydraulic press. The temperature of CaTiO3 synthesis was 1300 °C with a holding time of 4 hours. Experiments with a different carbon excess (20 and 30 wt.% of the content stoichiometrically required to recover perovskite components) were carried out. The carbothermic process of artificial perovskite decomposition (4 g pellets) was carried out in a vacuum furnace with a graphite heater in two stages: at 1500 °C, 1 hour holding time and 10,1 kPa residual pressure in an argon atmosphere at the first stage, and at t = 1750 °C, τ = 1 h, 1,3 Pa residual chamber pressure at the second one. Reaction products were studied by X-ray diffraction analysis on the «D8 Advance Bruker AXS» diffractometer. Experimental results demonstrated the practical possibility of titanium and calcium extraction from perovskite using the carbothermic method.","PeriodicalId":14523,"journal":{"name":"Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84746775","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 : 2018-10-12DOI: 10.17073/0021-3438-2018-5-39-47
K. Nikitin, I. Timoshkin, V. I. Nikitin
The study covers Al–Cu–Si (A34 grade) and Zn–Al–Cu (Welco52 grade) solders. It is found that A34 solder (Al–28%Cu–6%Si) melts and crystallizes in a narrow range of temperatures (~18 °C). Solidus and liquidus temperatures of A34 solder are ~508 °С and ~526 °С, respectively. Zn–Al–Cu (Zn–4%Al–2,5% Cu) solder has a eutectic composition, so it melts and crystallizes at a constant temperature of ~389 °С. Densities of investigated solders in their liquid and solid states are studied. A34 solder has a density of 3,02 and 3,32 g/cm3 , respectively. Zinc solder density is 6,28 g/cm3 in the liquid state, and 6,69 g/cm3 in the solid state. The influence of casting conditions on the structure of cast alloys in the form of bars with cross sections of 13, 10, and 5 mm2 was investigated. Main structural components of solder alloys reduce in size as cross sections decrease. The aluminium-based solid solution dendrites and CuAl2 phase are reduced in the A34 solder microstructure. In zinc solders, the most severely reduced ones are zinc-based solid solution dendrites. The best castability is observed in melts obtained from 5 mm2 section bar solders with studied sample gaps of 2,0, 1,5 and 1,0 mm. Eutectic zinc solder features better castability in comparison with A34: castability of the melt obtained from the 5 mm2 section zinc solder rod with a sample gap width of 2,0 mm is 100 % (for A34 melt solder obtained from a rod of the same cross section it was 98 %). Experiments on soldering AK12 alloy plates and 3003 alloy sheets demonstrated that there is a tight border in the solder/base material system and no any defects such as pores or unsoldered areas. There was a slight interpenetration of solder alloys into base materials, especially when soldering AK12 cast plates.
{"title":"STUDY INTO STRUCTURE AND PROPERTIES OF SOLDERS BASED ON ALUMINUM AND ZINC IN THE FORM OF SMALL-SECTION CAST BARS","authors":"K. Nikitin, I. Timoshkin, V. I. Nikitin","doi":"10.17073/0021-3438-2018-5-39-47","DOIUrl":"https://doi.org/10.17073/0021-3438-2018-5-39-47","url":null,"abstract":"The study covers Al–Cu–Si (A34 grade) and Zn–Al–Cu (Welco52 grade) solders. It is found that A34 solder (Al–28%Cu–6%Si) melts and crystallizes in a narrow range of temperatures (~18 °C). Solidus and liquidus temperatures of A34 solder are ~508 °С and ~526 °С, respectively. Zn–Al–Cu (Zn–4%Al–2,5% Cu) solder has a eutectic composition, so it melts and crystallizes at a constant temperature of ~389 °С. Densities of investigated solders in their liquid and solid states are studied. A34 solder has a density of 3,02 and 3,32 g/cm3 , respectively. Zinc solder density is 6,28 g/cm3 in the liquid state, and 6,69 g/cm3 in the solid state. The influence of casting conditions on the structure of cast alloys in the form of bars with cross sections of 13, 10, and 5 mm2 was investigated. Main structural components of solder alloys reduce in size as cross sections decrease. The aluminium-based solid solution dendrites and CuAl2 phase are reduced in the A34 solder microstructure. In zinc solders, the most severely reduced ones are zinc-based solid solution dendrites. The best castability is observed in melts obtained from 5 mm2 section bar solders with studied sample gaps of 2,0, 1,5 and 1,0 mm. Eutectic zinc solder features better castability in comparison with A34: castability of the melt obtained from the 5 mm2 section zinc solder rod with a sample gap width of 2,0 mm is 100 % (for A34 melt solder obtained from a rod of the same cross section it was 98 %). Experiments on soldering AK12 alloy plates and 3003 alloy sheets demonstrated that there is a tight border in the solder/base material system and no any defects such as pores or unsoldered areas. There was a slight interpenetration of solder alloys into base materials, especially when soldering AK12 cast plates.","PeriodicalId":14523,"journal":{"name":"Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82783777","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 : 2018-08-16DOI: 10.17073/0021-3438-2018-4-4-14
M. N. Sabanova, N. Orekhova, O. Gorlova, I. Glagoleva
The paper studies the patterns of copper slag mineral phase separation by flotation depending on the modification of the additional BTF series collecting agent (dialkyldithiophosphate derivatives) and the ratio of main and additional collecting agent consumptions. The results of open and locked-cycle laboratory flotation tests are presented, and the effect of pulp pH on copper extraction is observed. The reasons for the copper extraction gain during grinding and subsequent flotation in acidic medium are analyzed. The aggregates of copper and iron sulfides are identified in slags thus proving decoppering effectiveness with a decrease in pH to slightly acidic values due to the active flotation of intergrown pieces of copper-containing phases with iron sulfide (pyrite, pyrrhotine). It is shown that the additional BTF series collecting agent added to the main collecting agent – potassium butyl xanthate – makes it possible to reduce the total consumption of the combined collecting agents while maintaining copper extraction and concentrate quality as compared to the consumption of only xanthate necessary to achieve the same parameters. The best results were achieved with the use of the BTF 1614 reagent in combination with potassium butyl xanthate at the BCC : BTF = 3 : 1 ratio. At an optimum pH = 5,5÷6,8, the increase in copper extraction to the concentrate was 11.13%, and gold and silver extraction increased by 9.68% and 9.93%, respectively.
{"title":"THE EFFECT OF DIALKYLDITHIOPHOSPHATE REAGENTS ON COPPER FLOTATION FROM PYRITIC SLAGS","authors":"M. N. Sabanova, N. Orekhova, O. Gorlova, I. Glagoleva","doi":"10.17073/0021-3438-2018-4-4-14","DOIUrl":"https://doi.org/10.17073/0021-3438-2018-4-4-14","url":null,"abstract":"The paper studies the patterns of copper slag mineral phase separation by flotation depending on the modification of the additional BTF series collecting agent (dialkyldithiophosphate derivatives) and the ratio of main and additional collecting agent consumptions. The results of open and locked-cycle laboratory flotation tests are presented, and the effect of pulp pH on copper extraction is observed. The reasons for the copper extraction gain during grinding and subsequent flotation in acidic medium are analyzed. The aggregates of copper and iron sulfides are identified in slags thus proving decoppering effectiveness with a decrease in pH to slightly acidic values due to the active flotation of intergrown pieces of copper-containing phases with iron sulfide (pyrite, pyrrhotine). It is shown that the additional BTF series collecting agent added to the main collecting agent – potassium butyl xanthate – makes it possible to reduce the total consumption of the combined collecting agents while maintaining copper extraction and concentrate quality as compared to the consumption of only xanthate necessary to achieve the same parameters. The best results were achieved with the use of the BTF 1614 reagent in combination with potassium butyl xanthate at the BCC : BTF = 3 : 1 ratio. At an optimum pH = 5,5÷6,8, the increase in copper extraction to the concentrate was 11.13%, and gold and silver extraction increased by 9.68% and 9.93%, respectively.","PeriodicalId":14523,"journal":{"name":"Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84143134","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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