Acid sludge, a by-product of the Cu smelting process rich in Pb, Se, Cu, Hg, and other valuable metals, is a highly recyclable smelting material. Due to its high selenium content and various phase structures that form inter-chemical and inclusion structures with associated minerals such as copper and mercury, selective separation and recovery of Pb, Cu, Se, Hg and other components are limited. To address this problem, a cascade separation process of “H2SO4 + NaClO3 oxidized coordinated leaching—HCl and Na2SO3 selective reduction of selenium—H2C2O4 reduction of copper precipitation—NaH2PO2 reduction of mercury precipitation” was used for the efficient recovery of these metals from acidic sludge. The results showed that excellent outcomes have been obtained under optimal process parameters at each stage. In the oxidation leaching stage, Pb remains in the slag, Se, Cu, and Hg are leached into the solution, and the leaching rate is above 99%. Under appropriate concentrations of hydrochloric acid, Se was selectively separated in a complexation reaction with Na2SO3. The precipitation rate for Se was almost 100%, with Se product purity reaching up to 99.4%. After that, the precipitation rate of Cu in the oxalic acid precipitation is more than 99%, and the precipitation rate of Hg in the sodium hypophosphite reduction process is more than 99%. In addition, 99.09% of total lead, 97.64% of total selenium, 98.97% of total copper and 98.08% of total mercury in the acid sludge entered their separation products. During the process, the acid sludge's metals are effectively separated without introducing difficult impurity ions.
{"title":"Gradient Separation and Recovery of Pb, Se, Cu, and Hg from Acid Sludge by a Sustainable Hydrometallurgical Process","authors":"Xuexian Jiang, Wenyun Zhu, Wei Liu, Guixiang He, Tao Wei, Yongming Yang, Zhonglin Li, Changmao Liao, Cheng Li, Weiguang Zhang, Yibing Li, Xuejiao Cao","doi":"10.1007/s40831-024-00892-5","DOIUrl":"https://doi.org/10.1007/s40831-024-00892-5","url":null,"abstract":"<p>Acid sludge, a by-product of the Cu smelting process rich in Pb, Se, Cu, Hg, and other valuable metals, is a highly recyclable smelting material. Due to its high selenium content and various phase structures that form inter-chemical and inclusion structures with associated minerals such as copper and mercury, selective separation and recovery of Pb, Cu, Se, Hg and other components are limited. To address this problem, a cascade separation process of “H<sub>2</sub>SO<sub>4</sub> + NaClO<sub>3</sub> oxidized coordinated leaching—HCl and Na<sub>2</sub>SO<sub>3</sub> selective reduction of selenium—H<sub>2</sub>C<sub>2</sub>O<sub>4</sub> reduction of copper precipitation—NaH<sub>2</sub>PO<sub>2</sub> reduction of mercury precipitation” was used for the efficient recovery of these metals from acidic sludge. The results showed that excellent outcomes have been obtained under optimal process parameters at each stage. In the oxidation leaching stage, Pb remains in the slag, Se, Cu, and Hg are leached into the solution, and the leaching rate is above 99%. Under appropriate concentrations of hydrochloric acid, Se was selectively separated in a complexation reaction with Na<sub>2</sub>SO<sub>3</sub>. The precipitation rate for Se was almost 100%, with Se product purity reaching up to 99.4%. After that, the precipitation rate of Cu in the oxalic acid precipitation is more than 99%, and the precipitation rate of Hg in the sodium hypophosphite reduction process is more than 99%. In addition, 99.09% of total lead, 97.64% of total selenium, 98.97% of total copper and 98.08% of total mercury in the acid sludge entered their separation products. During the process, the acid sludge's metals are effectively separated without introducing difficult impurity ions.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>\u0000","PeriodicalId":17160,"journal":{"name":"Journal of Sustainable Metallurgy","volume":"5 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199571","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 : 2024-08-12DOI: 10.1007/s40831-024-00896-1
Yulin Li, Jintao Gao, Xi Lan, Xiang Ji, Zhancheng Guo
Bayan Obo, located in Inner Mongolia, China, is renowned for housing the world’s largest deposit of iron-niobium-rare earth polymetallic co-associated minerals. During the process of developing and exploiting this deposit, rare earth elements and other valuable minerals are incorporated into the slag phase, resulting in a significant secondary source of rare earth resources. To effectively recover the rare earth elements, supergravity technology was used to selectively separate the three distinct rare earth phases in the CaO-SiO2-La2O3 basic slag system. The process yielded three rare earth phase pure crystals, namely La2Ca3(SiO3)6, CaxLa4.67-x(SiO4)3O1-0.5x, and LaxCa2-x(SiO4)O0.5x, which were obtained under specific conditions: a gravity coefficient of G = 1000, separation time of t = 10 min, and crystallization temperature for respective each rare earth phase (1330 °C, 1350 °C, 1600 °C). Comprehensive characterization of these crystals was conducted using Raman spectroscopy, EPMA, and XRF. The results indicated that the La2O3 content in the three rare earth phases was approximately 40 wt.%, 75 wt.%, and 20 wt.%, respectively. Notably, the CaxLa4.67-x(SiO4)3O1-0.5× phase exhibited the highest La2O3 content, making it the most valuable phase for rare earth enrichment. This study supplements the knowledge of rare earth phases in CaO-SiO2-La2O3 basic slag system, providing a theoretical reference for efficient recovery of rare earth resources and sustainable utilization of RE-bearing slag.
{"title":"Separation and Characterization of Multiple Rare Earth Phases in CaO-SiO2-La2O3 Basic Slag System","authors":"Yulin Li, Jintao Gao, Xi Lan, Xiang Ji, Zhancheng Guo","doi":"10.1007/s40831-024-00896-1","DOIUrl":"https://doi.org/10.1007/s40831-024-00896-1","url":null,"abstract":"<p>Bayan Obo, located in Inner Mongolia, China, is renowned for housing the world’s largest deposit of iron-niobium-rare earth polymetallic co-associated minerals. During the process of developing and exploiting this deposit, rare earth elements and other valuable minerals are incorporated into the slag phase, resulting in a significant secondary source of rare earth resources. To effectively recover the rare earth elements, supergravity technology was used to selectively separate the three distinct rare earth phases in the CaO-SiO<sub>2</sub>-La<sub>2</sub>O<sub>3</sub> basic slag system. The process yielded three rare earth phase pure crystals, namely La<sub>2</sub>Ca<sub>3</sub>(SiO<sub>3</sub>)<sub>6</sub>, Ca<sub>x</sub>La<sub>4.67-x</sub>(SiO<sub>4</sub>)<sub>3</sub>O<sub>1-0.5x</sub>, and La<sub>x</sub>Ca<sub>2-x</sub>(SiO<sub>4</sub>)O<sub>0.5x</sub>, which were obtained under specific conditions: a gravity coefficient of <i>G</i> = 1000, separation time of <i>t</i> = 10 min, and crystallization temperature for respective each rare earth phase (1330 °C, 1350 °C, 1600 °C). Comprehensive characterization of these crystals was conducted using Raman spectroscopy, EPMA, and XRF. The results indicated that the La<sub>2</sub>O<sub>3</sub> content in the three rare earth phases was approximately 40 wt.%, 75 wt.%, and 20 wt.%, respectively. Notably, the Ca<sub>x</sub>La<sub>4.67-x</sub>(SiO<sub>4</sub>)<sub>3</sub>O<sub>1-0.5×</sub> phase exhibited the highest La<sub>2</sub>O<sub>3</sub> content, making it the most valuable phase for rare earth enrichment. This study supplements the knowledge of rare earth phases in CaO-SiO<sub>2</sub>-La<sub>2</sub>O<sub>3</sub> basic slag system, providing a theoretical reference for efficient recovery of rare earth resources and sustainable utilization of RE-bearing slag.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>\u0000","PeriodicalId":17160,"journal":{"name":"Journal of Sustainable Metallurgy","volume":"91 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199573","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 : 2024-08-12DOI: 10.1007/s40831-024-00894-3
Tingting Lu, Zhengbiao Hu, Hongliang Zhao, Shuai Deng
Slurry electrolysis (SE) is a hydrometallurgical technology that offers notable advantages in the efficient extraction of metals from complex minerals while minimizing carbon emissions. This study aimed to investigate the characteristics of solid suspension within a 1:6 scaled cold water model, employing a combination of high-speed imaging and fiber probe measurements. The effects of stirring speed (N, 60–200 rpm), solid mass concentration (c, 175–357 g/L), liquid level height (H, 270–330 mm) on the clear liquid layer, axial and radial solid concentrations, and tank homogeneity were assessed. It was found that the flow was smooth at the solid–liquid interface, with the absence of significant vortexes formations at the center. On the horizontal plane, the distribution of solid concentration was observed to be uniform in the middle region, gradually increasing toward the edges. Notably, when the stirring speed reached N = 200 rpm, the tank achieved uniform suspension, which corresponds to a speed range of 33–52 rpm in the SE prototype. The relationship between stirring speed and solid concentration was analyzed, showing that the interaction between particles cannot be ignored. Furthermore, increasing the liquid level contributes to reducing fluctuation in the liquid surface, the tank exhibited the highest level of homogeneity when the liquid level height was set to H = 300 mm.
Graphical Abstract
泥浆电解（SE）是一种湿法冶金技术，在从复杂矿物中高效提取金属方面具有显著优势，同时还能最大限度地减少碳排放。本研究采用高速成像和纤维探针测量相结合的方法，旨在研究 1:6 比例冷水模型中固体悬浮物的特性。研究评估了搅拌速度（N，60-200 rpm）、固体质量浓度（c，175-357 g/L）、液面高度（H，270-330 mm）对透明液层、轴向和径向固体浓度以及水槽均匀性的影响。结果发现，固液界面处的流动平稳，中心没有明显的涡流形成。在水平面上，观察到固体浓度在中间区域分布均匀，向边缘逐渐增加。值得注意的是，当搅拌速度达到 N = 200 rpm 时，罐内的悬浮液达到均匀，这与 SE 原型中 33-52 rpm 的速度范围相对应。分析了搅拌速度与固体浓度之间的关系，结果表明颗粒之间的相互作用不容忽视。此外，提高液面高度有助于减少液面波动，当液面高度设定为 H = 300 毫米时，罐体表现出最高的均匀度。
{"title":"Study on Solid Suspension Characteristics in a Laboratory-Scale Slurry Electrolysis Stirring Tank","authors":"Tingting Lu, Zhengbiao Hu, Hongliang Zhao, Shuai Deng","doi":"10.1007/s40831-024-00894-3","DOIUrl":"https://doi.org/10.1007/s40831-024-00894-3","url":null,"abstract":"<p>Slurry electrolysis (SE) is a hydrometallurgical technology that offers notable advantages in the efficient extraction of metals from complex minerals while minimizing carbon emissions. This study aimed to investigate the characteristics of solid suspension within a 1:6 scaled cold water model, employing a combination of high-speed imaging and fiber probe measurements. The effects of stirring speed (<i>N</i>, 60–200 rpm), solid mass concentration (<i>c</i>, 175–357 g/L), liquid level height (<i>H</i>, 270–330 mm) on the clear liquid layer, axial and radial solid concentrations, and tank homogeneity were assessed. It was found that the flow was smooth at the solid–liquid interface, with the absence of significant vortexes formations at the center. On the horizontal plane, the distribution of solid concentration was observed to be uniform in the middle region, gradually increasing toward the edges. Notably, when the stirring speed reached <i>N</i> = 200 rpm, the tank achieved uniform suspension, which corresponds to a speed range of 33–52 rpm in the SE prototype. The relationship between stirring speed and solid concentration was analyzed, showing that the interaction between particles cannot be ignored. Furthermore, increasing the liquid level contributes to reducing fluctuation in the liquid surface, the tank exhibited the highest level of homogeneity when the liquid level height was set to <i>H</i> = 300 mm.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>\u0000","PeriodicalId":17160,"journal":{"name":"Journal of Sustainable Metallurgy","volume":"52 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199591","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 : 2024-08-12DOI: 10.1007/s40831-024-00895-2
Anthony de Schutter, Luka Ceyssens, Giuseppe Granata, Tom Van Gerven
This work studies mineral carbonation of steel slags with the aim to reduce the amount of slag that is landfilled. Besides permanently storing carbon dioxide (CO2), carbonating the slags can improve their quality for use in beneficial applications and reduces the leaching of harmful heavy metals. In order to intensify the mineral carbonation process, mechanical activation is used to improve both the carbonation kinetics and yield. The milling is performed in a planetary ball mill which allows for high-intensity grinding, resulting in a fast reduction of the particle size and quick amorphization and disturbance of the crystal structure, allowing high reaction rates to be achieved. The effects of the three main processing parameters of a planetary ball mill—bead-to-powder ratio (R), bead size (D) and milling speed (S)—are investigated. Under optimal conditions, more than 50% of the maximum CO2 uptake is achieved in only 6 min, representing a very significant improvement over regular slurry carbonation. Quantitative XRD allows to identify the reactivity of the different crystalline phases present in the slag under different milling conditions. With the help of a mass balance, the formation of an inert outer layer consisting of silica (SiO2) is confirmed. This explains both the shell diffusion mechanism controlling the carbonation reaction and the total conversion being limited to 50–60%.
{"title":"Improving the Carbonation of Steel Slags Through Concurrent Wet Milling","authors":"Anthony de Schutter, Luka Ceyssens, Giuseppe Granata, Tom Van Gerven","doi":"10.1007/s40831-024-00895-2","DOIUrl":"https://doi.org/10.1007/s40831-024-00895-2","url":null,"abstract":"<p>This work studies mineral carbonation of steel slags with the aim to reduce the amount of slag that is landfilled. Besides permanently storing carbon dioxide (CO<sub>2</sub>), carbonating the slags can improve their quality for use in beneficial applications and reduces the leaching of harmful heavy metals. In order to intensify the mineral carbonation process, mechanical activation is used to improve both the carbonation kinetics and yield. The milling is performed in a planetary ball mill which allows for high-intensity grinding, resulting in a fast reduction of the particle size and quick amorphization and disturbance of the crystal structure, allowing high reaction rates to be achieved. The effects of the three main processing parameters of a planetary ball mill—bead-to-powder ratio <span>(R)</span>, bead size <span>(D)</span> and milling speed <span>(S)</span>—are investigated. Under optimal conditions, more than 50% of the maximum CO<sub>2</sub> uptake is achieved in only 6 min, representing a very significant improvement over regular slurry carbonation. Quantitative XRD allows to identify the reactivity of the different crystalline phases present in the slag under different milling conditions. With the help of a mass balance, the formation of an inert outer layer consisting of silica (SiO<sub>2</sub>) is confirmed. This explains both the shell diffusion mechanism controlling the carbonation reaction and the total conversion being limited to 50–60%.</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":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199597","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 : 2024-08-06DOI: 10.1007/s40831-024-00885-4
Desmond Attah-Kyei, Dmitry Sukhomlinov, Lassi Klemettinen, Radoslaw Michallik, Hugh O’Brien, Pekka Taskinen, Daniel Lindberg
Large amounts of slag are generated during pyrometallurgical processing in copper production. Due to the presence of valuable elements, the improper disposal of huge quantities of copper slag produced, results in significant loss of resources as well as environmental issues. Analyses of the copper slag show that it contains valuable metals, particularly copper and nickel. In this work, four biochars were employed as fossil-free reducing agents to recover valuable metals from the slag. Reduction experiments were performed in a vertical furnace at temperatures 1250, 1300 and 1350 °C for 60 min in order to investigate the effect of temperature. Moreover, the effect of time on reduction progress was studied at 1250 °C and the concentrations of CO and CO2 in the off-gas were measured with a gas analyzer. Copper slag was reacted with metallurgical coke for comparison and the products were analyzed with EPMA and LA-ICPMS. The results revealed that reduction rapidly progresses to the formation of metal alloy within 10 min. Valuable metals like copper, nickel and arsenic were the first to be reduced to the metal phase. As reduction time increased, iron was also reduced and combined with the metal droplet. The use of biochar as reductant was shown to be more effective than coke especially at lower temperatures. In addition, thermodynamic modelling was performed with FactSage and HSC and compared with the experimental results. The simulations with HSC showed the sequence of reactions taking place and the calculations by FactSage were in agreement with the experiments.
{"title":"Pyrometallurgical Reduction of Copper Slag with Biochar for Metal Recovery","authors":"Desmond Attah-Kyei, Dmitry Sukhomlinov, Lassi Klemettinen, Radoslaw Michallik, Hugh O’Brien, Pekka Taskinen, Daniel Lindberg","doi":"10.1007/s40831-024-00885-4","DOIUrl":"https://doi.org/10.1007/s40831-024-00885-4","url":null,"abstract":"<p>Large amounts of slag are generated during pyrometallurgical processing in copper production. Due to the presence of valuable elements, the improper disposal of huge quantities of copper slag produced, results in significant loss of resources as well as environmental issues. Analyses of the copper slag show that it contains valuable metals, particularly copper and nickel. In this work, four biochars were employed as fossil-free reducing agents to recover valuable metals from the slag. Reduction experiments were performed in a vertical furnace at temperatures 1250, 1300 and 1350 °C for 60 min in order to investigate the effect of temperature. Moreover, the effect of time on reduction progress was studied at 1250 °C and the concentrations of CO and CO<sub>2</sub> in the off-gas were measured with a gas analyzer. Copper slag was reacted with metallurgical coke for comparison and the products were analyzed with EPMA and LA-ICPMS. The results revealed that reduction rapidly progresses to the formation of metal alloy within 10 min. Valuable metals like copper, nickel and arsenic were the first to be reduced to the metal phase. As reduction time increased, iron was also reduced and combined with the metal droplet. The use of biochar as reductant was shown to be more effective than coke especially at lower temperatures. In addition, thermodynamic modelling was performed with FactSage and HSC and compared with the experimental results. The simulations with HSC showed the sequence of reactions taking place and the calculations by FactSage were in agreement with the experiments.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>","PeriodicalId":17160,"journal":{"name":"Journal of Sustainable Metallurgy","volume":"78 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141937830","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 : 2024-08-06DOI: 10.1007/s40831-024-00869-4
Mehmet Kayra Karacahan
The leaching behavior of pyrolusite minerals was examined in hydrochloric acid solutions, including oxalic acid, to evaluate the influence of various experimental conditions. The optimum parameters for the leaching process were found in the first stage, and the process's kinetics were assessed in the second. The concentrations of oxalic acid, hydrochloric acid, and temperature were chosen as independent variables in the optimization experiments, with the central composite design used to analyze the experimental data. The optimum concentrations for oxalic acid, hydrochloric acid, and temperature were determined to be 0.75 mol/L, 1.2 mol/L, and 60 °C, respectively. The leaching rate was determined to be 97.4% for 120 min of response time in optimum situations. The kinetic assessment experiments studied the effects of solid/liquid ratio, particle size, stirring speed, and temperature on the manganese leaching rate from pyrolusite. In the studies, the leaching rate was shown to rise with increasing temperature and stirring speed, as well as with decreasing particle size and solid/liquid ratio. The kinetic analysis revealed that the leaching kinetics matched the mixed kinetic model, and a mathematical model for the leaching process was developed. This process's activation energy was determined to be 29.05 kJ/mol.
{"title":"Optimization and Kinetic Study of Manganese Leaching from Pyrolusite Ore in Hydrochloric Acid Solutions with Oxalic Acid","authors":"Mehmet Kayra Karacahan","doi":"10.1007/s40831-024-00869-4","DOIUrl":"https://doi.org/10.1007/s40831-024-00869-4","url":null,"abstract":"<p>The leaching behavior of pyrolusite minerals was examined in hydrochloric acid solutions, including oxalic acid, to evaluate the influence of various experimental conditions. The optimum parameters for the leaching process were found in the first stage, and the process's kinetics were assessed in the second. The concentrations of oxalic acid, hydrochloric acid, and temperature were chosen as independent variables in the optimization experiments, with the central composite design used to analyze the experimental data. The optimum concentrations for oxalic acid, hydrochloric acid, and temperature were determined to be 0.75 mol/L, 1.2 mol/L, and 60 °C, respectively. The leaching rate was determined to be 97.4% for 120 min of response time in optimum situations. The kinetic assessment experiments studied the effects of solid/liquid ratio, particle size, stirring speed, and temperature on the manganese leaching rate from pyrolusite. In the studies, the leaching rate was shown to rise with increasing temperature and stirring speed, as well as with decreasing particle size and solid/liquid ratio. The kinetic analysis revealed that the leaching kinetics matched the mixed kinetic model, and a mathematical model for the leaching process was developed. This process's activation energy was determined to be 29.05 kJ/mol.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>\u0000","PeriodicalId":17160,"journal":{"name":"Journal of Sustainable Metallurgy","volume":"46 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141937836","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 : 2024-08-05DOI: 10.1007/s40831-024-00891-6
Humza Ashraf, B. Deniz Karahan
A novel method for the fabrication of nanoengineered, mixed transition metal oxide anode active material is proposed based on implementing liquid nitrogen treatment during the chemical precipitation process, for the first time in open literature. Such interference in the precipitation is believed to change the surface energy of the nuclei leading to differentiation in the growth process. To exemplify this hypothesis with an environmentally friendly approach, kitchen scourer pads, an existing waste, are used as a starting material instead of using a mixture of primary quality metals’ salts. Therefore, in this study, firstly, an optimization is realized to leach the scouring pad with 100% efficiency. Then, by applying a conventional chemical precipitation to this leachate at pH 5.5, Sample 1-P is produced. Herein, innovatively liquid nitrogen treatment is carried out during the chemical precipitation to produce Sample 2-P. Lastly, these precipitates (Samples 1-P, 2-P) are calcinated in the air to form mixed transition metal oxide powders: Samples 1 and 2, respectively. Structural, chemical, and morphological characterizations are carried out to examine the effect of liquid nitrogen treatment on the powders’ properties. To discuss the effect of nitrogen treatment on the electrochemical performances of the anode active materials (Sample 1 and Sample 2), galvanostatic tests are realized. The results show that Sample 2 demonstrates a higher 1st discharge capacity (1352 mAh/g) and retains 62% of its performance after 200 cycles when 50 mA/g current load is applied. Moreover, this electrode delivers around 500 mAh/g at 1 A/g current load. The remarkable cycle performance of Sample 2 is believed to be related to the superior chemical, structural, and physical properties of the electrode active material.
{"title":"Cryo-Assisted Nitrogen Treatment for the Fabrication of Nanoengineered, Mixed Transition Metal Oxide Anode from Inorganic Domestic Waste, for Lithium-Ion Batteries","authors":"Humza Ashraf, B. Deniz Karahan","doi":"10.1007/s40831-024-00891-6","DOIUrl":"https://doi.org/10.1007/s40831-024-00891-6","url":null,"abstract":"<p>A novel method for the fabrication of nanoengineered, mixed transition metal oxide anode active material is proposed based on implementing liquid nitrogen treatment during the chemical precipitation process, for the first time in open literature. Such interference in the precipitation is believed to change the surface energy of the nuclei leading to differentiation in the growth process. To exemplify this hypothesis with an environmentally friendly approach, kitchen scourer pads, an existing waste, are used as a starting material instead of using a mixture of primary quality metals’ salts. Therefore, in this study, firstly, an optimization is realized to leach the scouring pad with 100% efficiency. Then, by applying a conventional chemical precipitation to this leachate at pH 5.5, Sample 1-P is produced. Herein, innovatively liquid nitrogen treatment is carried out during the chemical precipitation to produce Sample 2-P. Lastly, these precipitates (Samples 1-P, 2-P) are calcinated in the air to form mixed transition metal oxide powders: Samples 1 and 2, respectively. Structural, chemical, and morphological characterizations are carried out to examine the effect of liquid nitrogen treatment on the powders’ properties. To discuss the effect of nitrogen treatment on the electrochemical performances of the anode active materials (Sample 1 and Sample 2), galvanostatic tests are realized. The results show that Sample 2 demonstrates a higher 1st discharge capacity (1352 mAh/g) and retains 62% of its performance after 200 cycles when 50 mA/g current load is applied. Moreover, this electrode delivers around 500 mAh/g at 1 A/g current load. The remarkable cycle performance of Sample 2 is believed to be related to the superior chemical, structural, and physical properties of the electrode active material.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>\u0000","PeriodicalId":17160,"journal":{"name":"Journal of Sustainable Metallurgy","volume":"58 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141937831","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 : 2024-08-05DOI: 10.1007/s40831-024-00878-3
Matthew S. Humbert, Geoffrey A. Brooks, Alan R. Duffy, Chad Hargrave, M. Akbar Rhamdhani
The transition to green steel production is pivotal for reducing global carbon emissions. This study presents a comprehensive techno-economic analysis of various green steel production methods, including hydrogen reduction and three different electrolysis techniques: aqueous hydroxide electrolysis (AHE), molten salt electrolysis, and molten oxide electrolysis (MOE). By comparing process flow diagrams, capital and operational expenditures, specific energy consumption, and production footprint, this work provides a high-level assessment of the economic viability of these processes as they mature. The analysis reveals that MOE, despite its ongoing development, offers a promising route for iron production given its ability to process a wide range of ore qualities and the potential to sell electrolyte as a cement product. However, the best balance between deployment ready technology and economic benefit is AHE. Operational challenges are also discussed, such as electrolyte loss and slag handling. We suggest that the sale of by-products like oxygen may not significantly impact the economics due to market saturation. The findings underscore the importance of continued research and development in process optimization to realize the full potential of green steel technologies. All the calculations have been released as supplementary electronic material (MS Excel workbook). The format has been inspired by the techno-economic assessment template (TECHTEST) distributed by the US Dept. of Energy.
{"title":"Economics of Electrowinning Iron from Ore for Green Steel Production","authors":"Matthew S. Humbert, Geoffrey A. Brooks, Alan R. Duffy, Chad Hargrave, M. Akbar Rhamdhani","doi":"10.1007/s40831-024-00878-3","DOIUrl":"https://doi.org/10.1007/s40831-024-00878-3","url":null,"abstract":"<p>The transition to green steel production is pivotal for reducing global carbon emissions. This study presents a comprehensive techno-economic analysis of various green steel production methods, including hydrogen reduction and three different electrolysis techniques: aqueous hydroxide electrolysis (AHE), molten salt electrolysis, and molten oxide electrolysis (MOE). By comparing process flow diagrams, capital and operational expenditures, specific energy consumption, and production footprint, this work provides a high-level assessment of the economic viability of these processes as they mature. The analysis reveals that MOE, despite its ongoing development, offers a promising route for iron production given its ability to process a wide range of ore qualities and the potential to sell electrolyte as a cement product. However, the best balance between deployment ready technology and economic benefit is AHE. Operational challenges are also discussed, such as electrolyte loss and slag handling. We suggest that the sale of by-products like oxygen may not significantly impact the economics due to market saturation. The findings underscore the importance of continued research and development in process optimization to realize the full potential of green steel technologies. All the calculations have been released as supplementary electronic material (MS Excel workbook). The format has been inspired by the techno-economic assessment template (TECHTEST) distributed by the US Dept. of Energy.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>\u0000","PeriodicalId":17160,"journal":{"name":"Journal of Sustainable Metallurgy","volume":"97 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141937829","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 : 2024-08-02DOI: 10.1007/s40831-024-00862-x
Allan Runstedtler, Haining Gao
A process for thermal decomposition of methane to hydrogen and solid carbon is presented and examined. It utilizes the high-temperature heat from the slag by-product of blast furnace ironmaking to drive a thermal decomposition reaction, making it a waste-heat-to-hydrogen technology. This is accomplished via dry granulation of molten slag that feeds a fluidized bed reactor to effect methane–slag contact. First, the proposed process and the heat and mass balances are presented. It is found that it could produce an amount of hydrogen that is equivalent to about 20% of the reductant, depending on the iron-to-slag ratio. Then, a techno-economic analysis investigates the capital and operating costs of the process, compares the hydrogen production cost to that of other processes, and examines cost sensitivity to the prices of process inputs and outputs. This analysis suggests that the process would be suitable for on-site hydrogen production and use within a plant. In addition, using the hot slag to drive the methane decomposition would reduce hydrogen production cost by 15% compared to combusting a portion of the natural gas itself. Finally, a computational fluid dynamics (CFD) modeling study of the fluidized bed reactor examines the thermal decomposition of methane and its dependence on reaction kinetics as well as reactor design and operation. The bed operated in the bubbling regime at an average temperature between 1020 and 1060 °C and resulted in as high as 82% conversion of the methane to hydrogen, with additional optimization still possible.
{"title":"Hydrogen Production from Natural Gas Using Hot Blast Furnace Slag: Techno-economic Analysis and CFD Modeling","authors":"Allan Runstedtler, Haining Gao","doi":"10.1007/s40831-024-00862-x","DOIUrl":"https://doi.org/10.1007/s40831-024-00862-x","url":null,"abstract":"<p>A process for thermal decomposition of methane to hydrogen and solid carbon is presented and examined. It utilizes the high-temperature heat from the slag by-product of blast furnace ironmaking to drive a thermal decomposition reaction, making it a waste-heat-to-hydrogen technology. This is accomplished via dry granulation of molten slag that feeds a fluidized bed reactor to effect methane–slag contact. First, the proposed process and the heat and mass balances are presented. It is found that it could produce an amount of hydrogen that is equivalent to about 20% of the reductant, depending on the iron-to-slag ratio. Then, a techno-economic analysis investigates the capital and operating costs of the process, compares the hydrogen production cost to that of other processes, and examines cost sensitivity to the prices of process inputs and outputs. This analysis suggests that the process would be suitable for on-site hydrogen production and use within a plant. In addition, using the hot slag to drive the methane decomposition would reduce hydrogen production cost by 15% compared to combusting a portion of the natural gas itself. Finally, a computational fluid dynamics (CFD) modeling study of the fluidized bed reactor examines the thermal decomposition of methane and its dependence on reaction kinetics as well as reactor design and operation. The bed operated in the bubbling regime at an average temperature between 1020 and 1060 °C and resulted in as high as 82% conversion of the methane to hydrogen, with additional optimization still possible.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>\u0000","PeriodicalId":17160,"journal":{"name":"Journal of Sustainable Metallurgy","volume":"190 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141884909","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}
The increase in demand for lithium-ion batteries is due to their usage in many electronic gadgets and electric vehicles. Recycling spent lithium-ion batteries plays an essential role in reducing environmental pollution and material and economic scarcity. In this paper, we employed an efficient and environmentally friendly bio-carbon based carbothermal reduction followed by a water leaching process to recover lithium and cobalt from LiCoO2(LCO)-based lithium-ion batteries. Here, the carbonized flamboyant pods (CFP) are used as a reducing agent for the carbothermal reduction process. During the carbothermal reduction process, the bio-carbon converts LiCoO2 into Co3O4 and Li2CO3. Afterwards, lithium is leached out by deionized water with a leaching efficiency of 98%, leaving Co in the residue as Co3O4. This residue is further undergoing a smelting process to recover 98.5% of Co as Co3O4. This carbothermal green recovery process is energy conserving, environmentally friendly and will bring perspective for sustainable recycling of LIBs with a minimized secondary waste.
{"title":"Bio-Carbon Assisted Carbothermal Reduction Process for the Recovery of Lithium and Cobalt from the Spent Lithium-Ion Batteries","authors":"Akhila Vasamsetti, Arrthi Ravitchandiran, Saradh Prasad Rajendra, Mohamad S. AlSalhi, Rajamohan Rajaram, Subramania Angaiah","doi":"10.1007/s40831-024-00890-7","DOIUrl":"https://doi.org/10.1007/s40831-024-00890-7","url":null,"abstract":"<p>The increase in demand for lithium-ion batteries is due to their usage in many electronic gadgets and electric vehicles. Recycling spent lithium-ion batteries plays an essential role in reducing environmental pollution and material and economic scarcity. In this paper, we employed an efficient and environmentally friendly bio-carbon based carbothermal reduction followed by a water leaching process to recover lithium and cobalt from LiCoO<sub>2</sub>(LCO)-based lithium-ion batteries. Here, the carbonized flamboyant pods (CFP) are used as a reducing agent for the carbothermal reduction process. During the carbothermal reduction process, the bio-carbon converts LiCoO<sub>2</sub> into Co<sub>3</sub>O<sub>4</sub> and Li<sub>2</sub>CO<sub>3</sub>. Afterwards, lithium is leached out by deionized water with a leaching efficiency of 98%, leaving Co in the residue as Co<sub>3</sub>O<sub>4</sub>. This residue is further undergoing a smelting process to recover 98.5% of Co as Co<sub>3</sub>O<sub>4</sub>. This carbothermal green recovery process is energy conserving, environmentally friendly and will bring perspective for sustainable recycling of LIBs with a minimized secondary waste.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>\u0000","PeriodicalId":17160,"journal":{"name":"Journal of Sustainable Metallurgy","volume":"166 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141784141","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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