The knowledge of mineral filler characteristics and their impacts on filler–asphalt interfacial behavior is not systematic and completed yet. In this paper, eight mineral fillers prepared using the same milling procedure were investigated. The filler–asphalt interfacial behavior was analyzed by differential scanning calorimetric and dynamic shear rheometer tests. Results reveal that in contrast to form factor and specific surface area, particle porosity, particle density, aspect ratio, angularity index, fractal dimension and feature roughness decrease with decreasing particle size. Limestone filler exhibits more regular shape, less significant angularity and richer surface texture than basalt filler. Of all particle characteristics studied, form factor and specific surface area are suggested to be the determining factors affecting filler–asphalt interfacial behavior. Moreover, microscopic morphology analysis provides an insight to interpret the differences explored in mastic interfacial property. The results help employ applicable particle characteristics that fabricate mastic with a stable interface system.
{"title":"Influence of mineral filler characteristics on the filler–asphalt interfacial behavior","authors":"Baodong Xing , Chen Fang , Xiaobo Lyu , Weiyu Fan , Yuchao Lyu","doi":"10.1016/j.apt.2024.104636","DOIUrl":"10.1016/j.apt.2024.104636","url":null,"abstract":"<div><p>The knowledge of mineral filler characteristics and their impacts on filler–asphalt interfacial behavior is not systematic and completed yet. In this paper, eight mineral fillers prepared using the same milling procedure were investigated. The filler–asphalt interfacial behavior was analyzed by differential scanning calorimetric and dynamic shear rheometer tests. Results reveal that in contrast to form factor and specific surface area, particle porosity, particle density, aspect ratio, angularity index, fractal dimension and feature roughness decrease with decreasing particle size. Limestone filler exhibits more regular shape, less significant angularity and richer surface texture than basalt filler. Of all particle characteristics studied, form factor and specific surface area are suggested to be the determining factors affecting filler–asphalt interfacial behavior. Moreover, microscopic morphology analysis provides an insight to interpret the differences explored in mastic interfacial property. The results help employ applicable particle characteristics that fabricate mastic with a stable interface system.</p></div>","PeriodicalId":7232,"journal":{"name":"Advanced Powder Technology","volume":"35 10","pages":"Article 104636"},"PeriodicalIF":4.2,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142089370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-27DOI: 10.1016/j.apt.2024.104635
Hu Wen , Yuxin Li , Haitao Yin , Wei Wang , Zhengchao Jin , Shunyu Han , Nanzhe Jiang
The conversion of natural clay to crystalline zeolites has been the subject of considerable interest from both academic and industrial circles. We present an effective strategy for converting kaolin to ZSM-5 zeolite, addressing the issue of reduced mesopore formation in conventional nano-ZSM-5 aggregates due to close-packing. This strategy utilizes kaolin as the sole source of silicon and aluminum, and by decoupling the nucleation and growth of ZSM-5 crystals, loosely stacked nano-H-ZSM-5 aggregates with high crystallinity crystals can be synthesized in a solid-like system by employing a tiny amount of TPAOH (TPAOH/SiO2 = 0.064). The resulting nano-H-ZSM-5 aggregates exhibited high specific surface area (405.66 m2/g), high mesopore volume (0.64 cm3/g), and superior catalytic activity. This strategy offers a novel approach to the cost-effective synthesis of nano-H-ZSM-5 aggregates suitable for industrial applications.
{"title":"Simple and sustainable synthesis of loosely stacked nano-H-ZSM-5 aggregates from kaolin and catalytic studies","authors":"Hu Wen , Yuxin Li , Haitao Yin , Wei Wang , Zhengchao Jin , Shunyu Han , Nanzhe Jiang","doi":"10.1016/j.apt.2024.104635","DOIUrl":"10.1016/j.apt.2024.104635","url":null,"abstract":"<div><p>The conversion of natural clay to crystalline zeolites has been the subject of considerable interest from both academic and industrial circles. We present an effective strategy for converting kaolin to ZSM-5 zeolite, addressing the issue of reduced mesopore formation in conventional nano-ZSM-5 aggregates due to close-packing. This strategy utilizes kaolin as the sole source of silicon and aluminum, and by decoupling the nucleation and growth of ZSM-5 crystals, loosely stacked nano-H-ZSM-5 aggregates with high crystallinity crystals can be synthesized in a solid-like system by employing a tiny amount of TPAOH (TPAOH/SiO<sub>2</sub> = 0.064). The resulting nano-H-ZSM-5 aggregates exhibited high specific surface area (405.66 m<sup>2</sup>/g), high mesopore volume (0.64 cm<sup>3</sup>/g), and superior catalytic activity. This strategy offers a novel approach to the cost-effective synthesis of nano-H-ZSM-5 aggregates suitable for industrial applications.</p></div>","PeriodicalId":7232,"journal":{"name":"Advanced Powder Technology","volume":"35 10","pages":"Article 104635"},"PeriodicalIF":4.2,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142089369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-23DOI: 10.1016/j.apt.2024.104586
Zhenda Liu , Xiao Lin , Yanlong Hong , Lijie Zhao , Lan Shen
Porosity variations have an impact on the disintegration behavior of tablets whereas the influence on the disintegration characteristics of natural plant product (NPP) tablets has not been extensively studied. Revealing the pore structure of NPP tablets provides a new and important clue to elucidate the phenomenal behavior and underlying mechanisms of tablet disintegration. In this study, the effect of porosity variation on disintegration of NPP tablets was evaluated for the first time. The disintegration performance of NPP tablets was evaluated using tablet attributes, disintegration kinetics, and the wicking process. Mercury intrusion porosimetry (MIP) and X-ray computed microtomography (XμCT) were used to characterize the microstructure of the tablets. Curcuma Longa Linn. extractions were compacted into tablets with different solid fractions. Tablet qualities changed significantly with increasing porosity. An increase in the wicking rate with porosity changed by visualizing the wicking process. The disintegration kinetics of tablets showed a sensitive variation after an increase in porosity. The pore structure of tablets including parameters such as pore size distribution, tortuosity, and connectivity were identified as direct drivers of wicking and disintegration. The current study provides new insights into the disintegration mechanism of dissolved NPP tablets by exploring the evolution of the pore microstructure.
{"title":"Exploring the disintegration mechanism of dissolved natural plant products tablets based on pore structure control","authors":"Zhenda Liu , Xiao Lin , Yanlong Hong , Lijie Zhao , Lan Shen","doi":"10.1016/j.apt.2024.104586","DOIUrl":"10.1016/j.apt.2024.104586","url":null,"abstract":"<div><p>Porosity variations have an impact on the disintegration behavior of tablets whereas the influence on the disintegration characteristics of natural plant product (NPP) tablets has not been extensively studied. Revealing the pore structure of NPP tablets provides a new and important clue to elucidate the phenomenal behavior and underlying mechanisms of tablet disintegration. In this study, the effect of porosity variation on disintegration of NPP tablets was evaluated for the first time. The disintegration performance of NPP tablets was evaluated using tablet attributes, disintegration kinetics, and the wicking process. Mercury intrusion porosimetry (MIP) and X-ray computed microtomography (XμCT) were used to characterize the microstructure of the tablets. <em>Curcuma Longa</em> Linn. extractions were compacted into tablets with different solid fractions. Tablet qualities changed significantly with increasing porosity. An increase in the wicking rate with porosity changed by visualizing the wicking process. The disintegration kinetics of tablets showed a sensitive variation after an increase in porosity. The pore structure of tablets including parameters such as pore size distribution, tortuosity, and connectivity were identified as direct drivers of wicking and disintegration. The current study provides new insights into the disintegration mechanism of dissolved NPP tablets by exploring the evolution of the pore microstructure.</p></div>","PeriodicalId":7232,"journal":{"name":"Advanced Powder Technology","volume":"35 10","pages":"Article 104586"},"PeriodicalIF":4.2,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142044978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The paper studied the structural features and physicomechanical properties of the WC–4wt.%TiC–3wt.%TaC–12wt.%Co composite refractory hard alloy system obtained by spark plasma sintering (SPS) from a preliminarily mechanically activated powder. It has been shown that preliminary mechanical activation in a planetary mill contributed to the comminution of agglomerates and the formation of a monomodal particle size distribution with a predominance of the submicron fraction, which intensifies the densification processes during subsequent consolidation by the SPS method. Kinetic analysis of the SPS process showed a two-stage sintering pattern with intense densification at temperatures above 790 °C due to rearrangement of WC, TiC, TaC particles and melting of the cobalt binder. It has been found that the SPS method does not lead to the formation of undesirable secondary phases in the entire sintering temperature range. A sintering temperature of 1200 °C is optimal for achieving the best structural homogeneity, density and mechanical properties, providing optimal distribution of carbide phases and the cobalt binder. The microstructure of the sample obtained at 1200 °C represents a refractory skeleton of WC grains with TiC and TaC carbide particles uniformly distributed throughout the volume. Improved fluidity of the melted cobalt binder and its mobile redistribution contribute to increased compactness of the structure and reduced porosity of the material. Samples sintered at 1200 °C possess high physicomechanical characteristics: relative density 99.99 %, hardness HV30 1623.2, bending strength 1125.1 MPa, fracture toughness 10.5 MN⋅m1/2. The abrasive wear resistance of a newly synthesized hard material was evaluated through a turning operation. Results showed durability, indicating promise for cutting tool applications and the need for further research to fully characterize the performance of this novel material.
{"title":"Microstructural evolution and mechanical behavior of WC–4wt.%TiC–3wt.%TaC–12wt.%Co refractory cermet consolidated by spark plasma sintering of mechanically activated powder mixtures","authors":"I.Yu. Buravlev , O.O. Shichalin , A.A. Belov , P.A. Marmaza , E.S. Kolodeznikov , M.I. Dvornik , A.N. Sakhnevich , A.A. Buravleva , S.V. Chuklinov , E.K. Papynov","doi":"10.1016/j.apt.2024.104625","DOIUrl":"10.1016/j.apt.2024.104625","url":null,"abstract":"<div><p>The paper studied the structural features and physicomechanical properties of the WC–4wt.%TiC–3wt.%TaC–12wt.%Co composite refractory hard alloy system obtained by spark plasma sintering (SPS) from a preliminarily mechanically activated powder. It has been shown that preliminary mechanical activation in a planetary mill contributed to the comminution of agglomerates and the formation of a monomodal particle size distribution with a predominance of the submicron fraction, which intensifies the densification processes during subsequent consolidation by the SPS method. Kinetic analysis of the SPS process showed a two-stage sintering pattern with intense densification at temperatures above 790 °C due to rearrangement of WC, TiC, TaC particles and melting of the cobalt binder. It has been found that the SPS method does not lead to the formation of undesirable secondary phases in the entire sintering temperature range. A sintering temperature of 1200 °C is optimal for achieving the best structural homogeneity, density and mechanical properties, providing optimal distribution of carbide phases and the cobalt binder. The microstructure of the sample obtained at 1200 °C represents a refractory skeleton of WC grains with TiC and TaC carbide particles uniformly distributed throughout the volume. Improved fluidity of the melted cobalt binder and its mobile redistribution contribute to increased compactness of the structure and reduced porosity of the material. Samples sintered at 1200 °C possess high physicomechanical characteristics: relative density 99.99 %, hardness HV30 1623.2, bending strength 1125.1 MPa, fracture toughness 10.5 MN⋅m<sup>1/2</sup>. The abrasive wear resistance of a newly synthesized hard material was evaluated through a turning operation. Results showed durability, indicating promise for cutting tool applications and the need for further research to fully characterize the performance of this novel material.</p></div>","PeriodicalId":7232,"journal":{"name":"Advanced Powder Technology","volume":"35 10","pages":"Article 104625"},"PeriodicalIF":4.2,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142011376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-21DOI: 10.1016/j.apt.2024.104621
Qilin Zhai, Yuwei Hu, Runqing Liu, Wei Sun
The remarkable differences in the metallurgical processes of copper and zinc require their host minerals to be separated as far as possible during beneficiation. For chalcopyrite and sphalerite, the primary host minerals of copper and zinc, their green and efficient separation in the beneficiation stage remains a great challenge. This work is the first to employ environmentally friendly pullulan polysaccharide (PP) as a sphalerite depressant to assist in the concentration of chalcopyrite. Flotation experiments have revealed that PP possesses a selective depression action on sphalerite without having a large influence on the recovery of chalcopyrite. Characterization analysis has revealed that PP can be adsorbed onto chalcopyrite and sphalerite surfaces, but with a different response to subsequent sorption collectors. PP adsorbs to the Zn atoms on sphalerite surfaces via its O atoms in the C−O−H group and thus prevents the adsorption of sodium butyl xanthate (BX). The Fe sites on the chalcopyrite surface can adsorb PP, but this process does not affect the BX adsorption as the Cu sites remain exposed. Hence, PP can enhance the hydrophilicity of sphalerite without interfering with the hydrophobicity of chalcopyrite, resulting in a desirable separation effect. Overall, this work offers a promising scheme for the concentration of chalcopyrite from sphalerite during beneficiation, thereby contributing to the efficient exploitation of copper and zinc resources.
{"title":"Investigation of pullulan polysaccharide as a sphalerite depressant for chalcopyrite separation: Flotation behavior and interfacial adsorption mechanism","authors":"Qilin Zhai, Yuwei Hu, Runqing Liu, Wei Sun","doi":"10.1016/j.apt.2024.104621","DOIUrl":"10.1016/j.apt.2024.104621","url":null,"abstract":"<div><p>The remarkable differences in the metallurgical processes of copper and zinc require their host minerals to be separated as far as possible during beneficiation. For chalcopyrite and sphalerite, the primary host minerals of copper and zinc, their green and efficient separation in the beneficiation stage remains a great challenge. This work is the first to employ environmentally friendly pullulan polysaccharide (PP) as a sphalerite depressant to assist in the concentration of chalcopyrite. Flotation experiments have revealed that PP possesses a selective depression action on sphalerite without having a large influence on the recovery of chalcopyrite. Characterization analysis has revealed that PP can be adsorbed onto chalcopyrite and sphalerite surfaces, but with a different response to subsequent sorption collectors. PP adsorbs to the Zn atoms on sphalerite surfaces via its O atoms in the C−O−H group and thus prevents the adsorption of sodium butyl xanthate (BX). The Fe sites on the chalcopyrite surface can adsorb PP, but this process does not affect the BX adsorption as the Cu sites remain exposed. Hence, PP can enhance the hydrophilicity of sphalerite without interfering with the hydrophobicity of chalcopyrite, resulting in a desirable separation effect. Overall, this work offers a promising scheme for the concentration of chalcopyrite from sphalerite during beneficiation, thereby contributing to the efficient exploitation of copper and zinc resources.</p></div>","PeriodicalId":7232,"journal":{"name":"Advanced Powder Technology","volume":"35 10","pages":"Article 104621"},"PeriodicalIF":4.2,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142012014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-19DOI: 10.1016/j.apt.2024.104624
Zigui Luo , Qi Jin , Rui Wang , Zhenjia Yang , Zhaoyang Wu , Guangqiang Li , Xi’an Fan
FeSiAl/(Al2O3-Ni) soft magnetic composites (SMCs) were prepared by sintering FeSiAl/NiO composite powders, and the formation mechanism of the Al2O3-Ni composite coating and performance of the FeSiAl SMCs with different NiO coating content were studied. During sintering, high temperature promoted a reaction between Al and NiO at the FeSiAl/NiO interface, resulting in the in-situ formation of a composite coating comprising Al2O3 coating with high integrity and ferromagnetic Ni coating. The interdiffusion of Al and O2– toward the interface ensured the continuation of the reaction and growth of the composite coating. The composite coating thickened with the increasing NiO coating content, thus showing reduced real part of permeability. Saturation magnetization considerably increased until the NiO coating content exceeded 12.5 wt% owing to residual NiO. Excessive NiO coating content led to the generation of a large amount of Ni, which was not conducive to the integrity of the Al2O3 coating and increased magnetic loss. The FeSiAl SMCs with 5.0 wt% NiO coating content exhibited exceptional performance with high saturation magnetization (135.3 emu/g), good frequency stability of permeability, and low magnetic loss (63.7 W/kg at 0.05 T/20 kHz).
{"title":"High-performance FeSiAl/(Al2O3-Ni) soft magnetic composites prepared by in situ synthesis method","authors":"Zigui Luo , Qi Jin , Rui Wang , Zhenjia Yang , Zhaoyang Wu , Guangqiang Li , Xi’an Fan","doi":"10.1016/j.apt.2024.104624","DOIUrl":"10.1016/j.apt.2024.104624","url":null,"abstract":"<div><p>FeSiAl/(Al<sub>2</sub>O<sub>3</sub>-Ni) soft magnetic composites (SMCs) were prepared by sintering FeSiAl/NiO composite powders, and the formation mechanism of the Al<sub>2</sub>O<sub>3</sub>-Ni composite coating and performance of the FeSiAl SMCs with different NiO coating content were studied. During sintering, high temperature promoted a reaction between Al and NiO at the FeSiAl/NiO interface, resulting in the in-situ formation of a composite coating comprising Al<sub>2</sub>O<sub>3</sub> coating with high integrity and ferromagnetic Ni coating. The interdiffusion of Al and O<sup>2–</sup> toward the interface ensured the continuation of the reaction and growth of the composite coating. The composite coating thickened with the increasing NiO coating content, thus showing reduced real part of permeability. Saturation magnetization considerably increased until the NiO coating content exceeded 12.5 wt% owing to residual NiO. Excessive NiO coating content led to the generation of a large amount of Ni, which was not conducive to the integrity of the Al<sub>2</sub>O<sub>3</sub> coating and increased magnetic loss. The FeSiAl SMCs with 5.0 wt% NiO coating content exhibited exceptional performance with high saturation magnetization (135.3 emu/g), good frequency stability of permeability, and low magnetic loss (63.7 W/kg at 0.05 T/20 kHz).</p></div>","PeriodicalId":7232,"journal":{"name":"Advanced Powder Technology","volume":"35 10","pages":"Article 104624"},"PeriodicalIF":4.2,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142012013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-17DOI: 10.1016/j.apt.2024.104613
C.Y. Wang , L. Fang
Aiming at explaining the short-time dust emission from belt conveyors, an analytical scaling law model framework is introduced, employing the same assumptions and wall models as traditional numerical simulations. Further, assuming a piecewise mean velocity profile, the Lagrangian mean velocity of dust particles can be written as a general expression. This expression is validated in various cases, including the 2D Belt, 3D Belt, 2D Tire, and 3D Tire cases. Numerical results show that the theoretical prediction, with key parameters fixed at , and , fits well with the simulated Lagrangian mean velocity profiles. For example, in the 2D Belt case, short-time agreement is achieved within s, indicating the model’s effectiveness in predicting dust dispersion within this time frame.
为了解释带式输送机的短时粉尘排放,本文引入了一个分析缩放定律模型框架,采用了与传统数值模拟相同的假设和壁面模型。此外,假定存在片断平均速度剖面,粉尘颗粒的拉格朗日平均速度可以写成一般表达式。该表达式在各种情况下都得到了验证,包括二维带状、三维带状、二维轮胎和三维轮胎情况。数值结果表明,在关键参数固定为 us=5、κ=0.4187 和 E=9.793 的情况下,理论预测结果与模拟的拉格朗日平均速度曲线非常吻合。例如,在 2D Belt 案例中,在 t⩽1 秒内实现了短时吻合,这表明该模型能有效预测该时间范围内的尘埃弥散。
{"title":"An analytical scaling law model framework for short-time dust emission from belt conveyor","authors":"C.Y. Wang , L. Fang","doi":"10.1016/j.apt.2024.104613","DOIUrl":"10.1016/j.apt.2024.104613","url":null,"abstract":"<div><p>Aiming at explaining the short-time dust emission from belt conveyors, an analytical scaling law model framework is introduced, employing the same assumptions and wall models as traditional numerical simulations. Further, assuming a piecewise mean velocity profile, the Lagrangian mean velocity of dust particles can be written as a general expression. This expression is validated in various cases, including the 2D Belt, 3D Belt, 2D Tire, and 3D Tire cases. Numerical results show that the theoretical prediction, with key parameters fixed at <span><math><mrow><msub><mrow><mi>u</mi></mrow><mrow><mi>s</mi></mrow></msub><mo>=</mo><mn>5</mn><mo>,</mo><mi>κ</mi><mo>=</mo><mn>0.4187</mn></mrow></math></span>, and <span><math><mrow><mi>E</mi><mo>=</mo><mn>9.793</mn></mrow></math></span>, fits well with the simulated Lagrangian mean velocity profiles. For example, in the 2D Belt case, short-time agreement is achieved within <span><math><mrow><mi>t</mi><mo>⩽</mo><mn>1</mn></mrow></math></span> s, indicating the model’s effectiveness in predicting dust dispersion within this time frame.</p></div>","PeriodicalId":7232,"journal":{"name":"Advanced Powder Technology","volume":"35 10","pages":"Article 104613"},"PeriodicalIF":4.2,"publicationDate":"2024-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141998597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-16DOI: 10.1016/j.apt.2024.104622
Silvia Volpato, Andrea C. Santomaso
This experimental study aims to enhance the understanding of the correlation among equivalent particle diameters measured using two analytical techniques: optical analysis (assisted by computer aided image analysis) and permeability tests. The presence or absence of a specific analytical method or instrument can lead to the use of an incorrect equivalent diameter. Therefore, it can be beneficial to establish conversion rules between different equivalent particle diameters obtained through various methods and instruments. The optical analysis returns an equivalent diameter value inherently independent of particle arrangement since it deals with isolated particles. In contrast, the permeability test offers an equivalent mean diameter dependent not only on the size of the particles but also on their packed arrangement. A suitable correlation between the two diameters has been proposed, shown to be a decreasing function of porosity following a power law.
An unexpected outcome of the comparison between the optical method and permeametry is the possibility to isolate and characterize the effect that the packing arrangement has on pressure losses and to characterize it in terms of the tortuosity of the path that the fluid must travel through the packed bed. Our findings confirm a strong alignment between our tortuosity model, which contains the ratio between the two equivalent diameters considered here, and an empirical correlation from literature often utilized for predicting packed bed tortuosity.
{"title":"Investigation on particle size and packing tortuosity by coupling image analysis and permeability tests","authors":"Silvia Volpato, Andrea C. Santomaso","doi":"10.1016/j.apt.2024.104622","DOIUrl":"10.1016/j.apt.2024.104622","url":null,"abstract":"<div><p>This experimental study aims to enhance the understanding of the correlation among equivalent particle diameters measured using two analytical techniques: optical analysis (assisted by computer aided image analysis) and permeability tests. The presence or absence of a specific analytical method or instrument can lead to the use of an incorrect equivalent diameter. Therefore, it can be beneficial to establish conversion rules between different equivalent particle diameters obtained through various methods and instruments. The optical analysis returns an equivalent diameter value inherently independent of particle arrangement since it deals with isolated particles. In contrast, the permeability test offers an equivalent mean diameter dependent not only on the size of the particles but also on their packed arrangement. A suitable correlation between the two diameters has been proposed, shown to be a decreasing function of porosity following a power law.</p><p>An unexpected outcome of the comparison between the optical method and permeametry is the possibility to isolate and characterize the effect that the packing arrangement has on pressure losses and to characterize it in terms of the tortuosity of the path that the fluid must travel through the packed bed. Our findings confirm a strong alignment between our tortuosity model, which contains the ratio between the two equivalent diameters considered here, and an empirical correlation from literature often utilized for predicting packed bed tortuosity.</p></div>","PeriodicalId":7232,"journal":{"name":"Advanced Powder Technology","volume":"35 10","pages":"Article 104622"},"PeriodicalIF":4.2,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S092188312400298X/pdfft?md5=17d66007541b8ef7ddd156820b2ce391&pid=1-s2.0-S092188312400298X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141993525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-16DOI: 10.1016/j.apt.2024.104617
Boyang Liu , Chenglong Li , Xuejin Chen , Junchen Chen , Yun Zhou , Kai Sun , Runhua Fan , Dechang Jia
This study presents an innovative approach for synthesizing hierarchical porous carbon materials (HPCMs) tailored for high-performance supercapacitors. The proposed method combines oxidative foaming with self-activation, in-situ template, in-situ activation and template synthesis, respectively, utilizing glucose reactions with oxidizing agents like ammonium persulfate (APS), magnesium nitrate hexahydrate (MNH), and potassium persulfate (KPS). The process involves two stages: low-temperature foaming to initiate macropore formation and high-temperature annealing to create meso/micropores through in-situ template and activation. Generally, increasing the ratio of oxidant to glucose in the synthesis process can notably enhance the high specific surface area and pore volume of the HPCMs with a combination of micro/meso/macropores, exhibiting maximum values of 821 m2/g and 0.61 cm3/g (APS), 2077 m2/g and 3.05 cm3/g (MNH), 1845 m2/g and 1.29 cm3/g (KPS), respectively. Furthermore, the O and N, or S elements, can also be in-situ doped in the carbon framework. The hierarchical porous structure and the doping elements enhance the electrochemical performance of supercapacitors. The APS@4, with a high mass loading of 3.2 mg/cm2, exhibits a superior specific capacitance of 144 F/g and an areal capacitance of 456 mF/cm2 at a current density of 1 A/g. It demonstrates excellent cycling stability based on a capacitance retention of 100 % after 10,000 cycles.
{"title":"Oxidative foaming plus in-situ activation and template synthesis of hierarchical porous carbon for high-performance supercapacitors","authors":"Boyang Liu , Chenglong Li , Xuejin Chen , Junchen Chen , Yun Zhou , Kai Sun , Runhua Fan , Dechang Jia","doi":"10.1016/j.apt.2024.104617","DOIUrl":"10.1016/j.apt.2024.104617","url":null,"abstract":"<div><p>This study presents an innovative approach for synthesizing hierarchical porous carbon materials (HPCMs) tailored for high-performance supercapacitors. The proposed method combines oxidative foaming with self-activation, in-situ template, in-situ activation and template synthesis, respectively, utilizing glucose reactions with oxidizing agents like ammonium persulfate (APS), magnesium nitrate hexahydrate (MNH), and potassium persulfate (KPS). The process involves two stages: low-temperature foaming to initiate macropore formation and high-temperature annealing to create meso/micropores through in-situ template and activation. Generally, increasing the ratio of oxidant to glucose in the synthesis process can notably enhance the high specific surface area and pore volume of the HPCMs with a combination of micro/meso/macropores, exhibiting maximum values of 821 m<sup>2</sup>/g and 0.61 cm<sup>3</sup>/g (APS), 2077 m<sup>2</sup>/g and 3.05 cm<sup>3</sup>/g (MNH), 1845 m<sup>2</sup>/g and 1.29 cm<sup>3</sup>/g (KPS), respectively. Furthermore, the O and N, or S elements, can also be in-situ doped in the carbon framework. The hierarchical porous structure and the doping elements enhance the electrochemical performance of supercapacitors. The APS@4, with a high mass loading of 3.2 mg/cm<sup>2</sup>, exhibits a superior specific capacitance of 144 F/g and an areal capacitance of 456 mF/cm<sup>2</sup> at a current density of 1 A/g. It demonstrates excellent cycling stability based on a capacitance retention of 100 % after 10,000 cycles.</p></div>","PeriodicalId":7232,"journal":{"name":"Advanced Powder Technology","volume":"35 10","pages":"Article 104617"},"PeriodicalIF":4.2,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141993527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-16DOI: 10.1016/j.apt.2024.104615
Huifang Yang , Xiaoyu Cao , Jihui Luo , Jianxian Zeng , Xiaoping Huang , Jianrong Xue , Sheng Liu
In this study, an eco-friendly compound, carrageenan, was employed as a depressant for the selective separation of chalcopyrite and pyrite. The depressant performance and mechanism were comprehensively investigated. The results of the flotation experiments demonstrated that carrageenan exhibited selective depression towards pyrite as opposed to chalcopyrite, achieving flotation recoveries of 88.57 % for chalcopyrite and 9.57 % for pyrite with the combination of 2 × 10-5 mol/L SIBX and 20 mg/L carrageenan. The results of AFM and contact angle measurements revealed that carrageenan exhibited selective adsorption on pyrite surface, resulting in an enhancement in surface hydrophilicity. In contrast, the adsorption of carrageenan on chalcopyrite surface was found to be negligible. Zeta potential and XPS analyses further confirmed the chemisorption of carrageenan on the pyrite surface, indicating the reaction involving sulfuric acid and hydroxyl groups on carrageenan and Fe sites on pyrite. Therefore, carrageenan holds potential as a promising depressant for the selective separation of chalcopyrite from pyrite.
{"title":"Adsorption and depression mechanism of carrageenan on chalcopyrite and pyrite for the efficiency flotation separation","authors":"Huifang Yang , Xiaoyu Cao , Jihui Luo , Jianxian Zeng , Xiaoping Huang , Jianrong Xue , Sheng Liu","doi":"10.1016/j.apt.2024.104615","DOIUrl":"10.1016/j.apt.2024.104615","url":null,"abstract":"<div><p>In this study, an eco-friendly compound, carrageenan, was employed as a depressant for the selective separation of chalcopyrite and pyrite. The depressant performance and mechanism were comprehensively investigated. The results of the flotation experiments demonstrated that carrageenan exhibited selective depression towards pyrite as opposed to chalcopyrite, achieving flotation recoveries of 88.57 % for chalcopyrite and 9.57 % for pyrite with the combination of 2 × 10<sup>-5</sup> mol/L SIBX and 20 mg/L carrageenan. The results of AFM and contact angle measurements revealed that carrageenan exhibited selective adsorption on pyrite surface, resulting in an enhancement in surface hydrophilicity. In contrast, the adsorption of carrageenan on chalcopyrite surface was found to be negligible. Zeta potential and XPS analyses further confirmed the chemisorption of carrageenan on the pyrite surface, indicating the reaction involving sulfuric acid and hydroxyl groups on carrageenan and Fe sites on pyrite. Therefore, carrageenan holds potential as a promising depressant for the selective separation of chalcopyrite from pyrite.</p></div>","PeriodicalId":7232,"journal":{"name":"Advanced Powder Technology","volume":"35 10","pages":"Article 104615"},"PeriodicalIF":4.2,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141993528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}