Powder TechnologyPub Date : 2025-07-09DOI: 10.1016/j.powtec.2025.121379
Hongtao Li , Haitao Yang , Xin Wang , Jiaxin Cheng , Guohui Fu , Liansheng Xu , Qingping Chai
{"title":"Microstructural evolution and property correlation of Cu–Fe powders prepared by magnetic field fluidized bed electrodes","authors":"Hongtao Li , Haitao Yang , Xin Wang , Jiaxin Cheng , Guohui Fu , Liansheng Xu , Qingping Chai","doi":"10.1016/j.powtec.2025.121379","DOIUrl":"10.1016/j.powtec.2025.121379","url":null,"abstract":"<div><div>Cu–Fe powders have been extensively utilized in fields like diamond tools, friction materials and oil−impregnated bearings. Deficiencies still exist in the existing preparation methods for Cu–Fe powders regarding coating quality, preparation process and environmental protection, so new preparation techniques are required to be explored urgently. Through the combination of magnetic field fluidization and fluidized bed electrodes, a preparation method for metal−coated powders is innovated in this study, and Cu–Fe metal composite powders with excellent properties are successfully prepared via parameter optimization. A comparative analysis is carried out on the coating structures and electromagnetic properties of the powders prepared by the magnetic field fluidized bed electrodeposition method (Cu–Fe(E)) and the traditional displacement plating method (Cu–Fe(D)). It has been found in the research that the (111) and (220) crystal planes of Cu–Fe(E) are the preferentially growing crystal planes, with the peak shape being superior to that of Cu–Fe(D). At 4.5 GHz, the electromagnetic shielding effectiveness of Cu–Fe(E) powders can attain 14.61 dB, which is higher than that of Cu–Fe(D) powders. Under the pressure of 200 MPa, the electrical conductivity of Cu–Fe(E) powders is 18,337.64 S·cm<sup>−1</sup>, approximately eight times that of Cu–Fe(D) powders. Compared with the traditional displacement plating method, Cu–Fe(E) powders demonstrate more outstanding coating structures and properties, encompassing uniform and dense coatings, a more intact crystal structure, effectively enhanced electrical conductivity and electromagnetic shielding effectiveness. This novel magnetic field fluidized bed electrodeposition technology offers new perspectives for the field of Cu–Fe powder preparation.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"465 ","pages":"Article 121379"},"PeriodicalIF":4.5,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144656517","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}
Powder TechnologyPub Date : 2025-07-09DOI: 10.1016/j.powtec.2025.121375
Pengzhan Liu , Xin Zhang , Xiaopeng Shang , Duojia Shi , Morgan WeiZhi Tan , Guicai Liu , Shi Hao Lim , Hang Yin , Man Pun Wan , Grzegorz Lisak , Bing Feng Ng
{"title":"Ultrasonic agglomeration of flowing aerosol particles: Experiments and fixed pivot-based spatial population balance modeling","authors":"Pengzhan Liu , Xin Zhang , Xiaopeng Shang , Duojia Shi , Morgan WeiZhi Tan , Guicai Liu , Shi Hao Lim , Hang Yin , Man Pun Wan , Grzegorz Lisak , Bing Feng Ng","doi":"10.1016/j.powtec.2025.121375","DOIUrl":"10.1016/j.powtec.2025.121375","url":null,"abstract":"<div><div>Acoustic agglomeration (AA) is a promising technology for pre-conditioning of aerosol particles in industrial and civil settings. Although substantial experimental and modeling studies have been separately conducted under the temporal AA framework, systematic parallel experimental and numerical studies towards a deterministic spatial AA framework that may involve complex spatial inhomogeneity have few been executed yet. Here, we experimentally investigate the effects of ultrasonic agglomeration on spatial population evolutions of flowing aerosol particles. Parallelly, we develop a numerical algorithm that adapts the fixed pivot approach to perform the AA-induced spatial population balance modeling (FP-SPBM). Using this algorithm, the dependency of spatial AA performance on different parameters under both traveling-wave and standing-wave ultrasonic fields are numerically investigated. The results indicate that for a standardized initial particle size distribution (PSD), the peak position of particle number concentration (PNC) gradually shifts larger and the PNC peak drops continuously with spatial position under ultrasound. Specifically, across a 5-m distance, the position of PNC peak shifts from 2 μm to 2.4 μm, and the corresponding PNC peak drops by around 6.6 × 10<sup>4</sup> #/cm<sup>3</sup> with the sound pressure level, flow speed, and initial total PNC of 140 dB, 1 m/s and 1 × 10<sup>5</sup> #/cm<sup>3</sup>, respectively. This study successfully captures spatial population evolutions of aerosol particles caused by AA, paving a way to the AA designs of spatial operation conditions. Moreover, the FP-SPBM methodology can perform SPBM under complex acoustic scenarios and can become an efficient design tool to maximum spatial AA efficiencies for practical applications.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"465 ","pages":"Article 121375"},"PeriodicalIF":4.5,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144623563","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}
Powder TechnologyPub Date : 2025-07-08DOI: 10.1016/j.powtec.2025.121345
Fuqian Wan , Lifen Fang , Qiming Huang , Quanlin Shi , Guansheng Qi , Lulu Sun , Guoqiang Yan
{"title":"Influence of pre-injection of retardant fluid on the microscopic physicochemical structure of coal during the spontaneous combustion process","authors":"Fuqian Wan , Lifen Fang , Qiming Huang , Quanlin Shi , Guansheng Qi , Lulu Sun , Guoqiang Yan","doi":"10.1016/j.powtec.2025.121345","DOIUrl":"10.1016/j.powtec.2025.121345","url":null,"abstract":"<div><div>Pre-injection of blocking fluid is a preventive technology for the source of coal spontaneous combustion, which can effectively solve the fire problem caused by the natural oxidation of coal. This article combines low-temperature nitrogen adsorption, scanning electron microscopy, and infrared spectroscopy experiments to study the changes in pore and fracture structure, fractal characteristics, and functional group content of coal before and after treatment with blocking solution. The results showed that during the process of coal oxidation and heating, the specific surface area, large pore volume, and number of surface pore cracks of the blocked coal sample all decreased. At 200 °C, the fractal dimension of the blocked coal sample decreased the most significantly, by 2.54 %. At the same time, the proportion of fatty hydrocarbons and OH peak areas in the coal sample increases while the proportion of C<img>O and OH peak areas decreases, reducing the risk of coal spontaneous combustion. In the early stage (25 °C ∼ 200 °C), the inhibitory effect of the inhibitor solution is significant. As the temperature further increases (200 °C ∼ 300 °C), the inhibitory effect of the inhibitor decreases significantly. This study is of great significance for improving the application technology of inhibitors.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"465 ","pages":"Article 121345"},"PeriodicalIF":4.5,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144623564","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}
Powder TechnologyPub Date : 2025-07-08DOI: 10.1016/j.powtec.2025.121380
Yiming Zhang , Fan Xu , Huan Wang , Yongmin Zhang , Shuyue Li , Xiuhua Wu
{"title":"Comparison of hydrodynamics and operational characteristics of a multistage fluidized bed with high-density and low-density powders","authors":"Yiming Zhang , Fan Xu , Huan Wang , Yongmin Zhang , Shuyue Li , Xiuhua Wu","doi":"10.1016/j.powtec.2025.121380","DOIUrl":"10.1016/j.powtec.2025.121380","url":null,"abstract":"<div><div>Multistage fluidized bed reactors have advantages for higher gas-solids contact efficiency in uranium recycling processes, where uranium compound powders used have high densities, usually several times greater than those in chemical industry. However, little literature has compared hydrodynamics and operation of multistage fluidized beds used particles with significantly different densities. In this study, we compared similarities and differences in hydrodynamics and operational characteristics for wolfram carbide (15,630 kg/m<sup>3</sup>) and FCC (2200 kg/m<sup>3</sup>) powders with similar size in a three-stage fluidized bed. During the start-up period, severe difficulties were experienced in achieving stable operation with FCC particles. During stable operating range, the experimental results indicated that stable fluidization and circulation were achievable with two types of particles in the multistage fluidized bed, but large pressure drop fluctuation (FCC: 10–30 Pa; WC: 100–800 Pa) and wider stable operating range (FCC: 0.01–0.29 m/s; WC: 0.04–0.69 m/s) were observed using high-density particles. Higher-pressure drop distributors optimize high-density particles operation in multistage fluidized beds, improving fluidization quality while maintaining operating velocities within stable operating ranges.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"465 ","pages":"Article 121380"},"PeriodicalIF":4.5,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144604275","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}
Powder TechnologyPub Date : 2025-07-07DOI: 10.1016/j.powtec.2025.121362
Ling Xu , Chaoyan Qin , Yuan Zhao , Yuting Wu
{"title":"Study on mesoscopic structural evolution of aeolian loess driven by loading and water saturation using 3D micro-CT","authors":"Ling Xu , Chaoyan Qin , Yuan Zhao , Yuting Wu","doi":"10.1016/j.powtec.2025.121362","DOIUrl":"10.1016/j.powtec.2025.121362","url":null,"abstract":"<div><div>Aeolian deposition and subsequent consolidation processes play a fundamental role in shaping the initial structure of loess. Loading and saturating directly determine the special properties of undisturbed loess, but the understanding of the differences in their effects on the loess structure remains limited. This study conducted consolidation and collapse tests, followed by CT scanning to analyze the microscopic evolution of the initial aeolian loess structure under the effects of water and force. The results show that the orientation angle of the long axis (<em>PHI</em>) of large soil particles tends to concentrate at 45° under loading, whereas the <em>PHI</em> of large particles generally tends to tilt horizontally under saturation. Both consolidation loading and water saturation increase the fraction of pores in the specimen that have a larger shape factor (<em>SF</em>), indicating an increase in irregular pores. Results also illustrate that variations in the rotational behavior of skeletal particles under loading and saturation significantly influence the final microstructure. In dry soil conditions, the sequence of first saturating and then loading generates new structural voids, resulting in a final void ratio that is higher than the case of loading followed by saturation. Finally, this study provides a microscopic explanation for the shift in loess consolidation behavior caused by variations in loading and water saturation. This research enhances the understanding of the evolution of powder under external action.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"465 ","pages":"Article 121362"},"PeriodicalIF":4.5,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144597570","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}
Powder TechnologyPub Date : 2025-07-07DOI: 10.1016/j.powtec.2025.121371
Daming Wang , Zixin Zhang , Xinwen Hong , Shuo Shi , Yuqi Song , Yewei Zhu , Tao Lei
{"title":"Boosting semi-flexible asphalt pavement sustainability and performance with rice husk biochar particle","authors":"Daming Wang , Zixin Zhang , Xinwen Hong , Shuo Shi , Yuqi Song , Yewei Zhu , Tao Lei","doi":"10.1016/j.powtec.2025.121371","DOIUrl":"10.1016/j.powtec.2025.121371","url":null,"abstract":"<div><div>Developing low-carbon and carbon-sequestering pavement materials is significant for achieving the Paris Climate Agreement's “dual carbon” goals. The innovation of this study lies in the incorporation of rice husk biochar into semi-flexible pavements, which enhances rutting resistance, reduces the cement content in the grouting material, and contributes to energy conservation, emission reduction, and effective carbon sequestration. This forms the basis for the study's adherence to criteria for evaluating the performance of grouting materials with rice husk biochar, using tests for fluidity, flexural strength, compressive strength, and drying shrinkage. Comprehensive assessments were also conducted, including freeze-thaw splitting, immersion Marshall, immersion scattering, and rutting tests. These evaluations aimed to examine the effects of incorporating various amounts of rice husk biochar into the asphalt mixture matrix on water stability and high-temperature performance. Finally, the optimal content is determined from the above tests. The study shows that the internal blending ratio of rice husk biochar in grouting materials is 8 %. In the matrix of the asphalt mixture, the blending ratio is 12 %. The semi-flexible pavement performs best, with a 7.1 % improvement in high-temperature performance, a 15.0 % increase in shear strength, and improvements in residual stability, flexural stiffness modulus and freeze-thaw splitting tensile strength ratio.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"465 ","pages":"Article 121371"},"PeriodicalIF":4.5,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144604336","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}
Powder TechnologyPub Date : 2025-07-07DOI: 10.1016/j.powtec.2025.121302
Martin Kozakovic , David Kramolis , Maria Zednikova , Stanislav Parez , Jaromir Havlica
{"title":"Dynamic regimes in granular mixing: Effect of sliding friction and stirrer rotational frequency","authors":"Martin Kozakovic , David Kramolis , Maria Zednikova , Stanislav Parez , Jaromir Havlica","doi":"10.1016/j.powtec.2025.121302","DOIUrl":"10.1016/j.powtec.2025.121302","url":null,"abstract":"<div><div>The dynamics of granular mixing in a vertical cylindrical vessel with a flat-blade stirrer has been investigated by systematic discrete element method simulations. Three distinct dynamic regimes have been identified by examining stirrer rotational frequencies ranging from gentle stirring to conditions inducing substantial surface deformation and particle accumulation near vessel walls, and sliding friction coefficients ranging from effectively frictionless to very rough particles. In the low-friction regime, the bed behaves as a quasi-rigid body corotating with the agitator, resulting in minimal homogenization. Poor homogenization is also observed at high rotational frequencies and moderate to high friction, where strong centrifugal forces deform the granular bed into partially isolated regions. Optimal mixing is achieved at intermediate conditions, where balanced centrifugal and gravitational forces allow effective particle redistribution by sustained frictional contact rather than particle collision. Analysis of surface deformation, volume fraction, and particle velocities reveals how these regimes arise from competition between mechanical energy input and the internal resistance of the granular bed. These results provide quantitative guidance for the optimization of mixing processes.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"465 ","pages":"Article 121302"},"PeriodicalIF":4.5,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144611740","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}
Powder TechnologyPub Date : 2025-07-07DOI: 10.1016/j.powtec.2025.121370
Shuai Liu , Kangqi Liu , Liangwen Qi , Chenguang Wang , Guipeng Zhang , Dingbang Xiao
{"title":"Preparation of high-entropy oxides nanoparticles by electrical explosion","authors":"Shuai Liu , Kangqi Liu , Liangwen Qi , Chenguang Wang , Guipeng Zhang , Dingbang Xiao","doi":"10.1016/j.powtec.2025.121370","DOIUrl":"10.1016/j.powtec.2025.121370","url":null,"abstract":"<div><div>High-entropy oxides are a new class of materials consisting of five or more main elements in equimolar or near equimolar ratio, which have many excellent properties. In this study, high entropy oxide nanopowders with different structures are prepared by joint electrical explosion of wires for the first time, in which (FeCoNiCuZn)O is the rock salt phase, and (FeCoNiTiZn)O is the spinel phase. According to the results of SEM and TEM, the distribution of the five principal metals in the products of electrical explosion is relatively homogeneous, and the particle sizes of the products are mostly below 100 nm. XPS shows that the valence distribution of metal cations in the products is consistent with the ideal high-entropy oxides. According to the research findings, joint electrical explosion of metal wires is a new method for the preparation of high-entropy oxide nanopowders.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"465 ","pages":"Article 121370"},"PeriodicalIF":4.5,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144604279","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}
Powder TechnologyPub Date : 2025-07-06DOI: 10.1016/j.powtec.2025.121357
Shilin Gao, Zaiyin Ma, Haibin Zhang, Bofeng Bai
{"title":"Numerical study on effects of granular deformations on dense powder conveying using a modified two-fluid model","authors":"Shilin Gao, Zaiyin Ma, Haibin Zhang, Bofeng Bai","doi":"10.1016/j.powtec.2025.121357","DOIUrl":"10.1016/j.powtec.2025.121357","url":null,"abstract":"<div><div>Granular deformations exert significant effects on conveying dynamics, coupled with inherent multiscale nonlinearity and complex rheological characteristics of dense powder flows, necessitating further in-depth investigations to unveil dense powder conveying mechanisms. Based on the coupling of the multiple-state theory, granular deformations have been introduced into the modified two-fluid model (TFM) through the refinement of the mesoscopic solid-pressure model in this study. To validate the modified TFM, a dense powder conveying experiment featuring a built-in fluidization gas intake structure was conducted, in which the instability of startup behaviors, directly affecting the optimization of conveying strategies, have been preliminarily identified. Moreover, a comparative analysis with multiple experimental results demonstrates the accuracy and reliability of the developed numerical model, highlighting the necessity of accounting for granular deformations. Using the modified TFM, the startup behaviors of dense powder conveying were thoroughly analyzed, revealing effects of granular deformations on increasing peak powder flow rates and the solid-gas ratio, indicating the non-ideal linearity of powder flow rate and fluidization pressure, and illustrating the decompression process within the powder layer. Additionally, inhomogeneous local solid-pressure concentrations within the powder flow resulting from the internal structures and fluidizing gas, and their impacts on conveying dynamics were captured in the simulations. The findings could provide valuable insights into the details of dense powder conveying and present a novel numerical approach, contributing significantly to the design and optimization of granular systems.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"465 ","pages":"Article 121357"},"PeriodicalIF":4.5,"publicationDate":"2025-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144588501","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}
{"title":"Multi-response optimization on porosity and mechanical properties of alumina-based ceramic core","authors":"Elahe Ayoubi , Mohsen Karimi , Mansoor Bozorg , Amir Mahdi Shabani , Salahoddin Isafi","doi":"10.1016/j.powtec.2025.121358","DOIUrl":"10.1016/j.powtec.2025.121358","url":null,"abstract":"<div><div>Alumina-based ceramic cores were fabricated using a mixture of two commercial alumina powders, and zircon and magnesia as additives. The effect of zircon and magnesia content, particle size distribution, and sintering temperature on the bending strength and porosity of produced ceramic cores was investigated. Concurrent optimizing of bending strength and porosity was done using Taguchi's robust design and an L9 array. By assigning equal weights to bend strength and porosity, the optimal settings of the process parameters to achieve the optimal combinations of bending strength and porosity were obtained: Particle size distribution (30Wt%MR70–70Wt%MR42), magnesia (1.5Wt.%), zircon (25Wt.%) and sintering temperature (1400 °C). The analysis of the sample produced in optimal conditions showed good sintering shrinkage, low thermal expansion coefficient (so good shock resistance and dimensional stability), excellent ambient and high temperature bending strength values (91 and 100 MPa at ambient temperature and 1200 °C, respectively), and suitable porosity (∼30 %).</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"465 ","pages":"Article 121358"},"PeriodicalIF":4.5,"publicationDate":"2025-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144597574","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}