Pub Date : 2024-05-02DOI: 10.1007/s40831-024-00821-6
Xiaoqing Fang, Wenqiang Sun, Chunyou Zuo, Menglin Liu
In pursuit of energy-efficient solutions for air supply systems in steel plants, this study introduces a novel hybrid air supply system, amalgamating Waste Heat Recovery (WHR) and Excess Pressure Recovery (EPR) units. The system integrates an expander in the WHR unit and a gas turbine in the EPR unit, coaxially aligning them with the blower. A 4E model is established to evaluate the system’s energy, exergy, economic, and environmental performance. Results highlight R236ea as optimal, boasting a net power output of 1072.07 kW and an exergy efficiency of 35.62%. The WHR and EPR units contribute 73.36 and 26.64%, respectively, resulting in an electricity saving of 8.38% for the blast furnace. The minimum cost per unit of net power output with R236ea is 0.0229 $/kWh, with a dynamic payback period of 1.66 years. Compared to traditional electro-driven systems, the proposed system yields a 14.23% total cost saving. R1233zd(E) facilitates the largest net emission reduction at 202.86 kt per year, operating at an evaporation temperature of 84.3 °C. This hybrid air supply system demonstrates significant practical value, offering simultaneous benefits in energy savings, cost reduction, and emission reduction, suggesting a promising avenue for future research and development in air supply systems.
{"title":"Design and 4E Analysis of a Hybrid Air Supply System for Blast Furnaces Driven by Excess Pressure and Waste Heat Recovery","authors":"Xiaoqing Fang, Wenqiang Sun, Chunyou Zuo, Menglin Liu","doi":"10.1007/s40831-024-00821-6","DOIUrl":"https://doi.org/10.1007/s40831-024-00821-6","url":null,"abstract":"<p>In pursuit of energy-efficient solutions for air supply systems in steel plants, this study introduces a novel hybrid air supply system, amalgamating Waste Heat Recovery (WHR) and Excess Pressure Recovery (EPR) units. The system integrates an expander in the WHR unit and a gas turbine in the EPR unit, coaxially aligning them with the blower. A 4E model is established to evaluate the system’s energy, exergy, economic, and environmental performance. Results highlight R236ea as optimal, boasting a net power output of 1072.07 kW and an exergy efficiency of 35.62%. The WHR and EPR units contribute 73.36 and 26.64%, respectively, resulting in an electricity saving of 8.38% for the blast furnace. The minimum cost per unit of net power output with R236ea is 0.0229 $/kWh, with a dynamic payback period of 1.66 years. Compared to traditional electro-driven systems, the proposed system yields a 14.23% total cost saving. R1233zd(E) facilitates the largest net emission reduction at 202.86 kt per year, operating at an evaporation temperature of 84.3 °C. This hybrid air supply system demonstrates significant practical value, offering simultaneous benefits in energy savings, cost reduction, and emission reduction, suggesting a promising avenue for future research and development in air supply systems.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>\u0000","PeriodicalId":17160,"journal":{"name":"Journal of Sustainable Metallurgy","volume":"21 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140828026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-01DOI: 10.1007/s40831-024-00825-2
G. Dall’Osto, D. Mombelli, V. Trombetta, C. Mapelli
Jarosite and blast furnace sludge (BFS) are two of the main wastes from hydrometallurgical zinc production and iron production by blast furnace, respectively. Jarosite is a hazardous material that can, however, be reused in the steel industry after the recovering of the iron contained within it through carbothermal reduction in which BFS is exploited as a reducing agent. Yet, both wastes have a powdery nature that makes it necessary to agglomerate them for industrial use. On the other hand, despite the advantages of producing a self-reducing product, the particle size of the starting powders and the level of gelatinization of the binder could play a crucial role on the mechanical and metallurgical performance and, consequently, on the industrial applicability of the briquettes. Accordingly, two powder particle sizes (very fine sand vs. coarse silt) and three degree of corn starch binder retrogradation (10%, 30% and non-gelatinized starch) were used to produce briquettes, and their influence was studied by experimental and statistical investigation. The results showed that gelatinization plays the main role on the mechanical properties of briquettes, while particle size affects both density and reduction behavior; in particular, although all the mixtures were able to recover iron at 950 °C the most optimal mixture were obtained by using a granulometry of 63–125 µm for jarosite and less than 63 µm for BFS, while the local maximum of mechanical performance was obtained for a 30% starch retrogradation level.
{"title":"Effect of Particle Size and Starch Gelatinization on the Mechanical and Metallurgical Performance of Jarosite Plus Blast Furnace Sludge Self-Reducing Briquettes","authors":"G. Dall’Osto, D. Mombelli, V. Trombetta, C. Mapelli","doi":"10.1007/s40831-024-00825-2","DOIUrl":"https://doi.org/10.1007/s40831-024-00825-2","url":null,"abstract":"<p>Jarosite and blast furnace sludge (BFS) are two of the main wastes from hydrometallurgical zinc production and iron production by blast furnace, respectively. Jarosite is a hazardous material that can, however, be reused in the steel industry after the recovering of the iron contained within it through carbothermal reduction in which BFS is exploited as a reducing agent. Yet, both wastes have a powdery nature that makes it necessary to agglomerate them for industrial use. On the other hand, despite the advantages of producing a self-reducing product, the particle size of the starting powders and the level of gelatinization of the binder could play a crucial role on the mechanical and metallurgical performance and, consequently, on the industrial applicability of the briquettes. Accordingly, two powder particle sizes (very fine sand vs. coarse silt) and three degree of corn starch binder retrogradation (10%, 30% and non-gelatinized starch) were used to produce briquettes, and their influence was studied by experimental and statistical investigation. The results showed that gelatinization plays the main role on the mechanical properties of briquettes, while particle size affects both density and reduction behavior; in particular, although all the mixtures were able to recover iron at 950 °C the most optimal mixture were obtained by using a granulometry of 63–125 µm for jarosite and less than 63 µm for BFS, while the local maximum of mechanical performance was obtained for a 30% starch retrogradation level.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>\u0000","PeriodicalId":17160,"journal":{"name":"Journal of Sustainable Metallurgy","volume":"45 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140828028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-30DOI: 10.1007/s40831-024-00830-5
B. N. Akhgar
This investigation presents a new method for preparing nano zero-valent iron (NZVI) from mechanically activated hematite. The XRD analysis indicated that even after 240 min mechanical activation (MA), the constituent phase of hematite could be detectable without any phase change. Regarding peak broadening and reduction of peak intensity, MA generally changed the microstructural properties of hematite with more intensity during the first 60 min of intensive planetary ball milling. The microstructural study performed by the Rietveld method also proved that all microstructural parameters changed in favor of the reactivity promotion of hematite. The amorphization degree and microstrain were increased to 83% and 0.16 (%), respectively, while crystallite size was reduced to 9.2 nm after 240 min MA. Therefore, MA could promote the hematite leachability where iron extraction was increased from 14% in initial hematite to 61% in 240 min mechanically activated hematite. Leaching efficiency increased even after surface area reduction and agglomeration in 240 min mechanically activated hematite. Consequently, the surface area parameter would not be the main factor in hematite reactivity promotion, as microstructural parameters changed in favor of hematite reactivity during MA. Among the microstructural parameters, the amorphization degree and crystallite size were the predominant parameters in the reactivity promotion of 60 min mechanically activated hematite and replaced with microstrain after 240 min MA. Also, NZVI was synthesized with titrating NaBH4 through chemical precipitation from the iron-bearing solutions obtained during mechanically activated hematite leaching tests. The XRD and FE-SEM analyses also revealed that NZVI was synthesized and fairly oxidized.
{"title":"Comparing the Microstructural Changes of Mechanically Activated Hematite During Nano Zero-Valent Iron Preparation","authors":"B. N. Akhgar","doi":"10.1007/s40831-024-00830-5","DOIUrl":"https://doi.org/10.1007/s40831-024-00830-5","url":null,"abstract":"<p>This investigation presents a new method for preparing nano zero-valent iron (NZVI) from mechanically activated hematite. The XRD analysis indicated that even after 240 min mechanical activation (MA), the constituent phase of hematite could be detectable without any phase change. Regarding peak broadening and reduction of peak intensity, MA generally changed the microstructural properties of hematite with more intensity during the first 60 min of intensive planetary ball milling. The microstructural study performed by the Rietveld method also proved that all microstructural parameters changed in favor of the reactivity promotion of hematite. The amorphization degree and microstrain were increased to 83% and 0.16 (%), respectively, while crystallite size was reduced to 9.2 nm after 240 min MA. Therefore, MA could promote the hematite leachability where iron extraction was increased from 14% in initial hematite to 61% in 240 min mechanically activated hematite. Leaching efficiency increased even after surface area reduction and agglomeration in 240 min mechanically activated hematite. Consequently, the surface area parameter would not be the main factor in hematite reactivity promotion, as microstructural parameters changed in favor of hematite reactivity during MA. Among the microstructural parameters, the amorphization degree and crystallite size were the predominant parameters in the reactivity promotion of 60 min mechanically activated hematite and replaced with microstrain after 240 min MA. Also, NZVI was synthesized with titrating NaBH<sub>4</sub> through chemical precipitation from the iron-bearing solutions obtained during mechanically activated hematite leaching tests. The XRD and FE-SEM analyses also revealed that NZVI was synthesized and fairly oxidized.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>\u0000","PeriodicalId":17160,"journal":{"name":"Journal of Sustainable Metallurgy","volume":"15 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140828154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-26DOI: 10.1007/s40831-024-00818-1
Zhen Zhang, Jue Tang, Mansheng Chu, Quan Shi, Chuanqiang Wang
At present, there were two main problems with the cooling plate slag-hanging: One was that the research on the slag-hanging mechanism of cooling plate was not deep, and the other was that the calculation process of the slag layer thickness with cooling plate was unreasonable. Based on ANSYS ‘birth–death element,’ a slag layer iterative cycle calculation method was designed, and the change of slag layer under different boundary conditions was analyzed. The gas temperature increased from 1200 to 1600 °C, and the slag layer decreased from 56 to 8 mm. When the gas temperature was 1550 °C, the copper cooling plate would exceeded safe operating temperature (120 °C). The thermal conductivity increased from 1.2 W·m2 °C−1 to 2.2 W·m2·°C−1, and the slag layer was able to be thickened by 76–85%; however, the slag layer would became non-uniform. When the temperature of slag-hanging increased by 50 °C, the slag layer increased by about 6.9 mm-7.6 mm, and the uniformity of slag layer increased by 10%. The maximum temperature of cooling plate could be reduced by 5°C–10°C when the cooling water speed increased by 1 m·s−1. The cooling water temperature was reduced by 10 °C, and the maximum temperature of cooling plate and the measuring point temperature could be reduced about 10 °C. The above research and analysis provided a basis for the blast furnace to have a reasonable operating furnace type and a longer life.
{"title":"Slag-Hanging Capacity of Numerical Simulation and Analysis of Blast Furnace Copper Cooling Plate Based on ANSYS ‘Birth–Death Element’","authors":"Zhen Zhang, Jue Tang, Mansheng Chu, Quan Shi, Chuanqiang Wang","doi":"10.1007/s40831-024-00818-1","DOIUrl":"https://doi.org/10.1007/s40831-024-00818-1","url":null,"abstract":"<p>At present, there were two main problems with the cooling plate slag-hanging: One was that the research on the slag-hanging mechanism of cooling plate was not deep, and the other was that the calculation process of the slag layer thickness with cooling plate was unreasonable. Based on ANSYS ‘birth–death element,’ a slag layer iterative cycle calculation method was designed, and the change of slag layer under different boundary conditions was analyzed. The gas temperature increased from 1200 to 1600 °C, and the slag layer decreased from 56 to 8 mm. When the gas temperature was 1550 °C, the copper cooling plate would exceeded safe operating temperature (120 °C). The thermal conductivity increased from 1.2 W·m<sup>2</sup> °C<sup>−1</sup> to 2.2 W·m<sup>2</sup>·°C<sup>−1</sup>, and the slag layer was able to be thickened by 76–85%; however, the slag layer would became non-uniform. When the temperature of slag-hanging increased by 50 °C, the slag layer increased by about 6.9 mm-7.6 mm, and the uniformity of slag layer increased by 10%. The maximum temperature of cooling plate could be reduced by 5°C–10°C when the cooling water speed increased by 1 m·s<sup>−1</sup>. The cooling water temperature was reduced by 10 °C, and the maximum temperature of cooling plate and the measuring point temperature could be reduced about 10 °C. The above research and analysis provided a basis for the blast furnace to have a reasonable operating furnace type and a longer life.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>\u0000","PeriodicalId":17160,"journal":{"name":"Journal of Sustainable Metallurgy","volume":"18 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140798320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-18DOI: 10.1007/s40831-024-00822-5
Aparna Sai Surya Sree Nedunuri, Salman Muhammad
Alkali-activated materials are one of the alternative cementitious materials, but their extensive usage is constrained by certain limitations, such as quick setting and rapid loss of workability. By addressing these limitations, this study developed alkali-activated concrete formulations, with enhanced workable times and pumpable workability, comprising of precursors based on fly ash and blast furnace slag. The precursors were activated with sodium silicate activator of molar modulus 1.5 and activator dosage (% of Na2O) of 8 and 10%. Zinc sulfate was incorporated as a retarder to prolong the workable times. The spread diameter of these concrete mixtures measured at 10th min was in the range of 650–745 mm. Several of the developed concrete mixtures could retain the spread diameters in the range of 430 – 655 mm for a duration longer than 90 min. These developed alkali-activated concrete mixtures with pumpable workability and prolonged workable times have exhibited compressive strengths in the range of M30 to M60 grade. The rheological behavior of these concrete mixtures was also assessed on their corresponding concrete equivalent mortar (CEM) mixtures. The yield stress and plastic viscosity of CEM mixtures were found to decrease with an increase in the proportion of fly ash and increase with an increase in the hydration time and retarder content. The evolution of yield stress and plastic viscosity of alkali-activated CEM mixtures were found to be in agreement with the obtained spread diameter values for concrete mixtures.
{"title":"Development of Sodium Silicate-Activated Ground Granulated Blast Furnace Slag and Fly Ash Binder-Based Concrete for Pumping Applications","authors":"Aparna Sai Surya Sree Nedunuri, Salman Muhammad","doi":"10.1007/s40831-024-00822-5","DOIUrl":"https://doi.org/10.1007/s40831-024-00822-5","url":null,"abstract":"<p>Alkali-activated materials are one of the alternative cementitious materials, but their extensive usage is constrained by certain limitations, such as quick setting and rapid loss of workability. By addressing these limitations, this study developed alkali-activated concrete formulations, with enhanced workable times and pumpable workability, comprising of precursors based on fly ash and blast furnace slag. The precursors were activated with sodium silicate activator of molar modulus 1.5 and activator dosage (% of Na<sub>2</sub>O) of 8 and 10%. Zinc sulfate was incorporated as a retarder to prolong the workable times. The spread diameter of these concrete mixtures measured at 10th min was in the range of 650–745 mm. Several of the developed concrete mixtures could retain the spread diameters in the range of 430 – 655 mm for a duration longer than 90 min. These developed alkali-activated concrete mixtures with pumpable workability and prolonged workable times have exhibited compressive strengths in the range of M30 to M60 grade. The rheological behavior of these concrete mixtures was also assessed on their corresponding concrete equivalent mortar (CEM) mixtures. The yield stress and plastic viscosity of CEM mixtures were found to decrease with an increase in the proportion of fly ash and increase with an increase in the hydration time and retarder content. The evolution of yield stress and plastic viscosity of alkali-activated CEM mixtures were found to be in agreement with the obtained spread diameter values for concrete mixtures.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>\u0000","PeriodicalId":17160,"journal":{"name":"Journal of Sustainable Metallurgy","volume":"27 1 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140629720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Monosilane (SiH4) is a common precursor for the production of high-purity silicon for solar PV applications. As an alternative to carbothermic reduction of silica to produce metallurgical grade silicon with subsequent conversion to silane, an alternative route over magnesiothermic reduction of silica to Mg2Si has been explored in our earlier work. In the current work, silane gas production through hydrolysis of Mg2Si in HCl acid solution was studied. Two sources of Mg2Si were chosen: a commercial Mg2Si source and a Mg2Si source produced through magnesiothermic reduction of high-purity natural quartz. Effects of various parameters on the hydrolysis of Mg2Si, including different experimental setups, temperature of the acid solution, acid concentration, reaction time, and relative amounts of reactants were studied. The evolution of produced gases was determined by two different methods: firstly, by passing the produced gas through a KOH solution to capture Si with subsequent analysis of the Si content in the KOH solution by inductively coupled plasma mass spectrometry and secondly, on-line gas analysis by GC–MS. The silane distribution between different silane species with reaction time was evaluated and the activation energy of silane formation was calculated. The results indicated comparable silane yields obtained from the on-line GC–MS method and KOH solution analysis method, as well as for commercial Mg2Si and the Mg2Si–MgO mixture produced through magnesiothermic reduction. Furthermore, adding HCl acid to Mg2Si in water led to higher SiH4 formation yield than adding Mg2Si to acid. However, the total silane yield for the two methods was similar at approximately 32%.
{"title":"Silane Gas Production Through Hydrolysis of Magnesium Silicide by Hydrochloric Acid","authors":"Azam Rasouli, Raphael Kuhn, Samson Yuxiu Lai, Jafar Safarian, Gabriella Tranell","doi":"10.1007/s40831-024-00817-2","DOIUrl":"https://doi.org/10.1007/s40831-024-00817-2","url":null,"abstract":"<p>Monosilane (SiH<sub>4</sub>) is a common precursor for the production of high-purity silicon for solar PV applications. As an alternative to carbothermic reduction of silica to produce metallurgical grade silicon with subsequent conversion to silane, an alternative route over magnesiothermic reduction of silica to Mg<sub>2</sub>Si has been explored in our earlier work. In the current work, silane gas production through hydrolysis of Mg<sub>2</sub>Si in HCl acid solution was studied. Two sources of Mg<sub>2</sub>Si were chosen: a commercial Mg<sub>2</sub>Si source and a Mg<sub>2</sub>Si source produced through magnesiothermic reduction of high-purity natural quartz. Effects of various parameters on the hydrolysis of Mg<sub>2</sub>Si, including different experimental setups, temperature of the acid solution, acid concentration, reaction time, and relative amounts of reactants were studied. The evolution of produced gases was determined by two different methods: firstly, by passing the produced gas through a KOH solution to capture Si with subsequent analysis of the Si content in the KOH solution by inductively coupled plasma mass spectrometry and secondly, on-line gas analysis by GC–MS. The silane distribution between different silane species with reaction time was evaluated and the activation energy of silane formation was calculated. The results indicated comparable silane yields obtained from the on-line GC–MS method and KOH solution analysis method, as well as for commercial Mg<sub>2</sub>Si and the Mg<sub>2</sub>Si–MgO mixture produced through magnesiothermic reduction. Furthermore, adding HCl acid to Mg<sub>2</sub>Si in water led to higher SiH<sub>4</sub> formation yield than adding Mg<sub>2</sub>Si to acid. However, the total silane yield for the two methods was similar at approximately 32%.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>\u0000","PeriodicalId":17160,"journal":{"name":"Journal of Sustainable Metallurgy","volume":"127 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140613083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-15DOI: 10.1007/s40831-024-00826-1
Yang Qu, Hongjie Luo, Zekun Zhi, Jinbo Qiao, Linli Wu
The growing scarcity of conventional oil resources has intensified the focus on shale oil, known for its abundant reserves. Nevertheless, in the process of shale oil retorting, a substantial quantity of harmful waste oil shale residue (OSR) is generated. In this study, OSR and bituminous coal sourced from Fushun City served as the raw materials for the production of Si–Al–Fe alloy in a DC electric arc furnace, proposing a novel way to efficiently utilize OSR. The experiment summarized and analyzed the current oxide reduction theory, combined with the actual experimental results, focused on investigating the phase transformations of OSR during the reduction process. Based on the gaseous suboxide-carbide reaction theory, the reduction mechanism of pellet raw materials at high temperature was proposed. Results showed that the pellet raw materials will first undergo high temperature decomposition during the reduction process, and generated a large amount of carbides. Carbides subsequently reacted with metal suboxides produced in the high-temperature zone of the electric arc furnace to yield alloys. The element distribution of the obtained alloy product was non-uniform, the metallic Si phase was closely adjacent to the SiC substance, and the Fe in the alloy significantly enriched the reduced Al and Ti elements.
Graphical Abstract
传统石油资源的日益匮乏使人们更加关注储量丰富的页岩油。然而，页岩油在蒸馏过程中会产生大量有害的废油页岩渣（OSR）。本研究以抚顺市的油页岩残渣和烟煤为原料，在直流电弧炉中生产硅-铝-铁合金，提出了一种高效利用油页岩残渣的新方法。实验总结分析了现有的氧化还原理论，结合实际实验结果，重点研究了氧化还原过程中氧化还原剂的相变。基于气态亚氧化物-碳化物反应理论，提出了球团原料在高温下的还原机理。结果表明，球团原料在还原过程中首先会发生高温分解，生成大量碳化物。碳化物随后与电弧炉高温区产生的金属亚氧化物反应生成合金。所得合金产品的元素分布不均匀，金属 Si 相紧邻 SiC 物质，合金中的 Fe 显著富集了还原的 Al 和 Ti 元素。
{"title":"Carbothermal Reduction of Oil Shale Residue (OSR) in DC Electric Furnace to Prepare Si–Al–Fe Alloy","authors":"Yang Qu, Hongjie Luo, Zekun Zhi, Jinbo Qiao, Linli Wu","doi":"10.1007/s40831-024-00826-1","DOIUrl":"https://doi.org/10.1007/s40831-024-00826-1","url":null,"abstract":"<p>The growing scarcity of conventional oil resources has intensified the focus on shale oil, known for its abundant reserves. Nevertheless, in the process of shale oil retorting, a substantial quantity of harmful waste oil shale residue (OSR) is generated. In this study, OSR and bituminous coal sourced from Fushun City served as the raw materials for the production of Si–Al–Fe alloy in a DC electric arc furnace, proposing a novel way to efficiently utilize OSR. The experiment summarized and analyzed the current oxide reduction theory, combined with the actual experimental results, focused on investigating the phase transformations of OSR during the reduction process. Based on the gaseous suboxide-carbide reaction theory, the reduction mechanism of pellet raw materials at high temperature was proposed. Results showed that the pellet raw materials will first undergo high temperature decomposition during the reduction process, and generated a large amount of carbides. Carbides subsequently reacted with metal suboxides produced in the high-temperature zone of the electric arc furnace to yield alloys. The element distribution of the obtained alloy product was non-uniform, the metallic Si phase was closely adjacent to the SiC substance, and the Fe in the alloy significantly enriched the reduced Al and Ti elements.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>\u0000","PeriodicalId":17160,"journal":{"name":"Journal of Sustainable Metallurgy","volume":"213 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140589406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-09DOI: 10.1007/s40831-024-00803-8
Sen Zhou, Mouhamadou A. Diop, Bingliang Gao, Zhaowen Wang, Xianwei Hu, Youjian Yang, Wenju Tao
The present study investigates the impact of erosion holes and subsequent repairs on the current distribution at the cathode-metal interface in aluminum reduction cells. The research focuses on examining the effects of erosion hole location, size, repair material properties, and the modification of cathode collector bars to optimize cathode repair strategies. The findings indicate that erosion holes lead to a localized concentration of current distribution in the metal at the erosion site. Notably, the maximum current density observed reaches 46125 A/m2, and the maximum horizontal current in the lateral cell direction at the cathode-metal interface increases with the depth of the erosion hole. Furthermore, the study reveals that the electrical conductivity of repair materials significantly influences current distribution. Materials with high resistivity behave similarly to insulators. Post-repair actions, including the cutting off of the collector bar, result in a noticeable reduction in current density, with a maximum horizontal current of 5860 A/m2. These results provide valuable insights into optimizing cathode repair processes, offering implications for enhancing aluminum reduction cells' efficiency, productivity, and cost-effectiveness.
{"title":"Enhancing Sustainability in Aluminum Reduction Cells Through Cathode Repair Optimization and Numerical Simulations Study on Current Distribution and Erosion Hole Impact","authors":"Sen Zhou, Mouhamadou A. Diop, Bingliang Gao, Zhaowen Wang, Xianwei Hu, Youjian Yang, Wenju Tao","doi":"10.1007/s40831-024-00803-8","DOIUrl":"https://doi.org/10.1007/s40831-024-00803-8","url":null,"abstract":"<p>The present study investigates the impact of erosion holes and subsequent repairs on the current distribution at the cathode-metal interface in aluminum reduction cells. The research focuses on examining the effects of erosion hole location, size, repair material properties, and the modification of cathode collector bars to optimize cathode repair strategies. The findings indicate that erosion holes lead to a localized concentration of current distribution in the metal at the erosion site. Notably, the maximum current density observed reaches 46125 A/m<sup>2</sup>, and the maximum horizontal current in the lateral cell direction at the cathode-metal interface increases with the depth of the erosion hole. Furthermore, the study reveals that the electrical conductivity of repair materials significantly influences current distribution. Materials with high resistivity behave similarly to insulators. Post-repair actions, including the cutting off of the collector bar, result in a noticeable reduction in current density, with a maximum horizontal current of 5860 A/m<sup>2</sup>. These results provide valuable insights into optimizing cathode repair processes, offering implications for enhancing aluminum reduction cells' efficiency, productivity, and cost-effectiveness.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>\u0000","PeriodicalId":17160,"journal":{"name":"Journal of Sustainable Metallurgy","volume":"77 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140602670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, we respectively added 5 wt% of Na2O and CaCl2 to the CaO–MgO–Al2O3–SiO2 base glass, aiming to analyze the effect of the types of flux, CaCl2, and traditional flux Na2O, on the crystallization behavior and mechanical properties of the sintered glass–ceramics. Besides, 1 wt% of Cr2O3 was added as the nucleating agent to form the Cr-spinel nucleus and promote the bulk crystallization. The CaCl2-bearing glass–ceramics (GC-Cl) showed lower porosity and crystallinity compared with the Na2O-bearing glass–ceramics (GC-Na). After sintering at 950 °C for 1 h, the bending strength, Vickers hardness, and fracture toughness of GC-Cl were 163 MPa, 6.9 GPa, and 2.4 MPa·m1/2, respectively, while they are 191 MPa, 8.2 GPa, and 2.3 MPa·m1/2 for the GC-Na. Although the bending strength and hardness of GC-Cl are lower than that of GC-Na, adding CaCl2 as a flux may provide a route for the comprehensive utilization of CaCl2-bearing wastes.
{"title":"Effects of Na2O and CaCl2 on the Crystallization and Mechanical Properties of CaO-MgO-Al2O3-SiO2 Glass–Ceramics","authors":"Hong-Yang Wang, Yu Li, Shu-Qiang Jiao, Guo-Hua Zhang","doi":"10.1007/s40831-024-00819-0","DOIUrl":"https://doi.org/10.1007/s40831-024-00819-0","url":null,"abstract":"<p>In this paper, we respectively added 5 wt% of Na<sub>2</sub>O and CaCl<sub>2</sub> to the CaO–MgO–Al<sub>2</sub>O<sub>3</sub>–SiO<sub>2</sub> base glass, aiming to analyze the effect of the types of flux, CaCl<sub>2</sub>, and traditional flux Na<sub>2</sub>O, on the crystallization behavior and mechanical properties of the sintered glass–ceramics. Besides, 1 wt% of Cr<sub>2</sub>O<sub>3</sub> was added as the nucleating agent to form the Cr-spinel nucleus and promote the bulk crystallization. The CaCl<sub>2</sub>-bearing glass–ceramics (GC-Cl) showed lower porosity and crystallinity compared with the Na<sub>2</sub>O-bearing glass–ceramics (GC-Na). After sintering at 950 °C for 1 h, the bending strength, Vickers hardness, and fracture toughness of GC-Cl were 163 MPa, 6.9 GPa, and 2.4 MPa·m<sup>1/2</sup>, respectively, while they are 191 MPa, 8.2 GPa, and 2.3 MPa·m<sup>1/2</sup> for the GC-Na. Although the bending strength and hardness of GC-Cl are lower than that of GC-Na, adding CaCl<sub>2</sub> as a flux may provide a route for the comprehensive utilization of CaCl<sub>2</sub>-bearing wastes.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>\u0000","PeriodicalId":17160,"journal":{"name":"Journal of Sustainable Metallurgy","volume":"33 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140589630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-08DOI: 10.1007/s40831-024-00815-4
Nand Peeters, Sofía Riaño, Koen Binnemans
A significant consequence of the green transition is the growing demand of lithium-ion batteries (LIBs), as they are essential for electrical vehicles. In turn, the demand for the raw materials that are needed to produce LIBs is increasing. A common LIB cathode type for electrical cars is lithium nickel manganese cobalt oxide (NMC). Since cobalt is currently considered as a critical raw material, nickel-rich NMC cathodes are now designed with lower cobalt contents. The synthesis of these new NMC types requires LiOH instead of Li2CO3, which was used for Co-richer NMC materials in the past. Most production routes of LiOH start from Li2CO3 or Li2SO4. However, LiCl could also be a potential precursor for LiOH, as it could be obtained from various lithium sources. A two-step solvent extraction process (SX) was developed for direct conversion of LiCl into LiOH, using a phenol (butylhydroxytoluene or BHT) and a mixture of quaternary ammonium chlorides (Aliquat 336) in an aliphatic diluent (Shellsol D70) as the solvent. The SX process was validated in counter-current mode using a rotary agitated Kühni extraction column. The use of a column instead of mixer-settlers reduced the CO2 uptake by the final product (LiOH), which prevented the partial conversion of LiOH to Li2CO3. A total of 75 L of LiCl feed solution was processed in the Kühni column to obtain a solution of LiOH with a final purity of more than 99.95%, at a yield of 96%.
{"title":"Conversion of Lithium Chloride into Lithium Hydroxide Using a Two-Step Solvent Extraction Process in an Agitated Kühni Column","authors":"Nand Peeters, Sofía Riaño, Koen Binnemans","doi":"10.1007/s40831-024-00815-4","DOIUrl":"https://doi.org/10.1007/s40831-024-00815-4","url":null,"abstract":"<p>A significant consequence of the green transition is the growing demand of lithium-ion batteries (LIBs), as they are essential for electrical vehicles. In turn, the demand for the raw materials that are needed to produce LIBs is increasing. A common LIB cathode type for electrical cars is lithium nickel manganese cobalt oxide (NMC). Since cobalt is currently considered as a critical raw material, nickel-rich NMC cathodes are now designed with lower cobalt contents. The synthesis of these new NMC types requires LiOH instead of Li<sub>2</sub>CO<sub>3</sub>, which was used for Co-richer NMC materials in the past. Most production routes of LiOH start from Li<sub>2</sub>CO<sub>3</sub> or Li<sub>2</sub>SO<sub>4</sub>. However, LiCl could also be a potential precursor for LiOH, as it could be obtained from various lithium sources. A two-step solvent extraction process (SX) was developed for direct conversion of LiCl into LiOH, using a phenol (butylhydroxytoluene or BHT) and a mixture of quaternary ammonium chlorides (Aliquat 336) in an aliphatic diluent (Shellsol D70) as the solvent. The SX process was validated in counter-current mode using a rotary agitated Kühni extraction column. The use of a column instead of mixer-settlers reduced the CO<sub>2</sub> uptake by the final product (LiOH), which prevented the partial conversion of LiOH to Li<sub>2</sub>CO<sub>3</sub>. A total of 75 L of LiCl feed solution was processed in the Kühni column to obtain a solution of LiOH with a final purity of more than 99.95%, at a yield of 96%.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>\u0000","PeriodicalId":17160,"journal":{"name":"Journal of Sustainable Metallurgy","volume":"213 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140589824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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