Powder Technology最新文献

{"title":"Hydration mechanisms of geopolymer grouting materials derived from circulating fluidized bed fly ash and ground granulated blast furnace slag","authors":"Hualei Wang ,&nbsp;Junhui Zhang ,&nbsp;Fan Gu","doi":"10.1016/j.powtec.2025.121402","DOIUrl":"10.1016/j.powtec.2025.121402","url":null,"abstract":"<div><div>The development of low-carbon geopolymer grouting materials using industrial byproducts is pivotal for sustainable infrastructure. This study deciphers the hydration mechanisms of circulating fluidized bed fly ash (CFBFA)-ground granulated blast furnace slag (GGBS) geopolymers via multiscale characterization. Mechanical tests identified a critical CFBFA threshold of 65 wt%, beyond this limit, 28-day compressive strength dropped from 23.6 MPa to 16.3 MPa, accompanied by reduced activity indices and elevated grout viscosity, linked to CFBFA's low combustion temperatures and irregular morphology. Isothermal calorimetry showed suppressed cumulative heat release above 65 wt% CFBFA, confirming retarded reaction kinetics. In situ X-ray diffraction (XRD)/Fourier transform infrared spectrometry (FTIR) analyses traced amorphous gel evolution, with FTIR bands shifting from 991 cm⁻¹ to 1010 cm⁻¹, signaling progressive Al³⁺ integration into aluminosilicate networks. Low-field nuclear magnetic resonance (NMR) highlighted delayed free-to-bound water transitions at higher CFBFA contents. High-field ²⁹Si MAS NMR revealed depolymerization trends, Q⁰ site abundance rose from 4.42 % to 18.71 %, while Q³ + Q⁴ content declined from 23.01 % to 3.56 % with increasing CFBFA. Scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) corroborated microstructural shifts from dense calcium-rich matrices (10.66 % Ca) to fractured sodium aluminosilicate networks (7.76 % Ca), with Si/(Al + Ca) ratios increasing from 1.19 to 1.29. A unified framework posits GGBS-driven early nucleation via rapid Ca²⁺ release, whereas CFBFA regulates long-term gel maturation through sustained Si⁴⁺ leaching. Optimized formulations (≤65 wt% CFBFA) balance reactivity and ion supply, ensuring robust mechanics and microstructural stability. These insights advance actionable strategies for eco-efficient geopolymer design in infrastructure rehabilitation.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"466 ","pages":"Article 121402"},"PeriodicalIF":4.6,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144750341","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":"The properties of nanocrystalline soft magnetic composites based on FeSiBNbCu@Fe3O4 powders prepared by one-step ball milling","authors":"Guibing Shi ,&nbsp;Helong Wang ,&nbsp;Mingxu Wang ,&nbsp;Bolin Li ,&nbsp;Mengrui Li ,&nbsp;Li Wang","doi":"10.1016/j.powtec.2025.121398","DOIUrl":"10.1016/j.powtec.2025.121398","url":null,"abstract":"<div><div>This study employs a one-step ball milling process to simultaneously achieve the fabrication of FeSiBCuNb nanocrystalline flaky powders and the insulating coating of nano-Fe₃O₄ particles. By systematically analyzing the microstructures of the coated powders, the relationship between the magnetic properties of the soft magnetic composites (SMCs) and the nano-Fe₃O₄ content is revealed. The results demonstrate that the introduction of appropriate amounts of nano-Fe₃O₄ can significantly optimize the uniformity of resin distribution on the surface of FeSiBCuNb particles, forming an efficient insulating isolation network, thereby achieving remarkable enhancement in the frequency stability and loss performances of SMCs. When the content of nano-Fe₃O₄ increases from 0 wt% to 4 wt%, the effective permeability of the SMCs first increases and then decreases, while the hysteresis losses first decreases and then increases. Compared with the SMCs without nano-Fe₃O₄ addition, the SMCs with 2 wt% nano-Fe₃O₄ addition exhibit excellent comprehensive magnetic properties: the effective permeability and DC-bias characteristics are maintained 49.7 (1 MHz) and 58 % (100 Oe), respectively. The losses are decreased from 1582.9 mW/cm³ to 723.7 mW/cm³ (20 mT, 1 MHz), and the frequency stability is improved from 1 MHz to 5 MHz. This process provides more options for SMCs used in inductors of DC/DC converters in the high-frequency field.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"466 ","pages":"Article 121398"},"PeriodicalIF":4.5,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679845","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":"Spray drying for pulmonary drug delivery: Comparing two- and three-fluid nozzles for porous particles production","authors":"Marcos Andrés Serain ,&nbsp;Verónica Bucalá ,&nbsp;Loreana Gallo","doi":"10.1016/j.powtec.2025.121390","DOIUrl":"10.1016/j.powtec.2025.121390","url":null,"abstract":"<div><div>The two most common nozzle types used in spray drying (SD) processes are the two (2-FN) and the three-fluid nozzle (3-FN). This study aimed to compare these configurations for the production of inhalable porous particles (PPs) intended for pulmonary drug delivery. Salbutamol sulfate (SS) was selected as a model antiasthmatic drug, while ammonium bicarbonate (AB) served as a pore-forming agent. The influence of nozzle type on drying efficiency, particle characteristics, and aerosolization performance was investigated.</div><div>A set of optimized conditions for the 2-FN was initially established and then used as a reference to evaluate the 3-FN. Subsequent experiments with the 3-FN explored variations in flow distribution between the internal and outer channels, along with different SS and AB concentrations. Although the 3-FN initially produced larger, less aerodynamic particles, fine-tuning of operating parameters and feed concentrations enabled the production of powders with satisfactory aerodynamic behavior. Remarkably, particles generated with the 3-FN exhibited aerosolization properties comparable to those of the 2-FN despite using up to four times lower concentrations of formulation components. FT-IR analysis confirmed the complete removal of AB post-drying, and long-term stability tests demonstrated preserved particle integrity and aerosol performance after six months of storage. This work provides the first comprehensive comparison of 2-FN and 3-FN for the production of inhalable PPs, unveiling the underexplored potential of 3-FN to generate high-quality inhalable powders under tailored conditions and with markedly lower component concentrations.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"466 ","pages":"Article 121390"},"PeriodicalIF":4.5,"publicationDate":"2025-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679703","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":"Characterizing the time dependent deposition of particles in a channel flow using optical coherence tomography","authors":"Taye Tolu Mekonnen ,&nbsp;Shaokoon Cheng ,&nbsp;Hak-Kim Chan ,&nbsp;Agisilaos Kourmatzis","doi":"10.1016/j.powtec.2025.121389","DOIUrl":"10.1016/j.powtec.2025.121389","url":null,"abstract":"<div><div>Understanding particle transport and deposition dynamics in confined flow regions is crucial for optimizing computational models and processes (e.g., filtration). However, the lack of suitable experimental methods to measure dynamic deposition has limited the ability to fully characterize transient deposition behavior. In this study, we present a high-resolution optical coherence tomography (OCT) technique to assess dynamic particle deposition characteristics in a particle-laden flow. The impact of flow rate, channel surface and particle properties were studied in a square channel using a pharmaceutical fine grade lactose powder (LH300, Dv50 = 5 μm) and a coarser grade lactose (SV010, Dv50 = 109 μm). Results showed a rapid increase in mean deposition thickness during the initial phase (&lt;2 s) of flow, followed by a relatively steady deposition thickness. At the downstream region, deposition rate of LH300 was significantly higher at 15 LPM compared to 30 LPM (<em>p</em> = 0.014) and 45 LPM (<em>p</em> = 0.027). At the entrance region, however, no significant variation in deposition rate with flow rate was observed, potentially due to the strong mixing effect of the still-developing flow profiles. The influence of particle size was evident, with SV010 showing a more closely spaced deposition clusters and higher deposition volume than LH300. The findings highlight the technique's potential to characterize dynamic deposition in two-phase flow, a functionality that holds promise for various applications.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"465 ","pages":"Article 121389"},"PeriodicalIF":4.5,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144656442","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":"Deep learning predicts shear stress in inclined dense granular flow","authors":"Chenyang Wang ,&nbsp;Wenhui Bai ,&nbsp;Tongming Qu ,&nbsp;Xiaoyan Ye","doi":"10.1016/j.powtec.2025.121246","DOIUrl":"10.1016/j.powtec.2025.121246","url":null,"abstract":"<div><div>Granular flow on slopes serves as a basic model to understand dynamic behavior of debris flows and landslides. However, the current phenomenological models remain incapable of capturing complex granular dynamics, especially for the critical transition in velocity profiles along slopes. This study employs deep learning to explore the constitutive behavior of dense granular flows. A stress-shear rate database for steady-state dense granular flows under various slope angles and thicknesses was constructed using the discrete element method (DEM). This data was utilized to develop a data-driven rheological constitutive model for slope-dense granular flows. The uncertainty of deep learning predictions was quantified using the Monte Carlo Dropout and committee-based methods, showing their potential for assessing the reliability of predictions. Additionally, Sharpley value analysis highlighted granular layer thickness, depth, and slope angle as pivotal factors governing the stress-shear rate relationship in inclined granular flows. The study shows that deep learning can serve as an alternative tool for capturing the intrinsic behavior of granular flow.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"466 ","pages":"Article 121246"},"PeriodicalIF":4.5,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144657139","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":"Study on the evolution law of coal body relaxation-mechanics coupling under the effect of different acidification environments","authors":"Yingxue Cui ,&nbsp;Guanhua Ni ,&nbsp;Zhao Li ,&nbsp;Gang Wang ,&nbsp;Yixin Liu ,&nbsp;Xu Wang","doi":"10.1016/j.powtec.2025.121386","DOIUrl":"10.1016/j.powtec.2025.121386","url":null,"abstract":"<div><div>Coal's pore structure and mechanical strength critically influence unconventional energy recovery, flow storage, and damage resistance. NMR and uniaxial compression tests analyzed acidification's effects on coal's pore structure, mechanical properties, and their NMR-mechanical coupling. The results show that the porosity of coal under saturated condition of acid treatment with different temperature and pressure conditions increases from 5.85 % to 10.35 % of the original coal, and the growth rate of <em>V</em>_fp ratio is 24.59 %, which indicates that the acid treatment can obviously improve the connectivity of coal and increase the porosity of coal, which is conducive to the diffusion and transport of coalbed methane; the coal samples have different relaxation and mechanical responses after treatment with different acidification conditions, and the NMR parameters <em>φ</em>_NMR、<em>T</em>_2gm、<em>T</em>_2am、<em>T</em>_2gmf, and <em>T</em>_2amf are negatively correlated with compressive strength and elastic modulus, respectively. It indicates that pore connectivity enhances the relaxation amplitude, and the strength and damage resistance of coals with large porosity are generally lower; there is a nonlinear fit between acidification conditions and relaxation mechanics, indicating that the acidification temperature-pressure conditions have significant sensitivity to the mechanical relaxation relationship. The temperature-pressure conditions have a negative effect on the structural integrity of the coal body, a positive effect on the relaxation, and a reverse effect on the mechanical response. The results of the research are of great significance for the recovery of unconventional natural gas such as coal bed methane (CBM) and can achieve the purpose of controlling the dust from the source.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"465 ","pages":"Article 121386"},"PeriodicalIF":4.5,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144632073","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":"Correlations development for drag and convective heat transfer coefficients of non-spherical particles at low-to-high Reynolds numbers by using direct numerical simulations","authors":"Yuhao Hu ,&nbsp;Zihan Liu ,&nbsp;Huaqing Ma ,&nbsp;Lianyong Zhou ,&nbsp;Yongzhi Zhao","doi":"10.1016/j.powtec.2025.121387","DOIUrl":"10.1016/j.powtec.2025.121387","url":null,"abstract":"<div><div>Particle flow and heat transfer phenomena at low-to-high Reynolds numbers (<em>Re</em>) (10−2000) are common in industrial processes such as pneumatic conveying and biomass combustion in thermal power plants. However, the applicability of closure correlations for both spherical and non-spherical particles at low-to-high <em>Re</em> has not been sufficiently studied, especially with regard to heat transfer. Driven by this fact, three-dimensional (3D) direct numerical simulation (DNS) based on the finite volume method (FVM) is used in this work to study the flow and heat transfer characteristics of particles with different geometric shapes. Through systematic regression analysis, novel closure correlations are established for the drag coefficient (<em>C</em>_<em>d</em>) and the Nusselt number (<em>Nu</em>) of spherical and non-spherical particles with a <em>Re</em> ranging from 10 to 2000, incorporating sphericity and transverse sphericity. The root mean square errors (RMSE) of the newly established correlations for the <em>C</em>_<em>d</em> and the <em>Nu</em> are 0.009 and 0.136 respectively, and the average relative deviations are 4.55 % and 1.7 % respectively. The proposed correlations offer reliable predictive capabilities within the specified <em>Re</em> range, providing essential closure terms for multiphase flow modeling involving spherical and non-spherical particles in academic research and industrial applications.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"465 ","pages":"Article 121387"},"PeriodicalIF":4.5,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144632072","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":"Crushing mechanism and influencing factors of gas-containing coal under water jet impact loading","authors":"Man Yuan ,&nbsp;Yingke Liu ,&nbsp;Yue Niu ,&nbsp;Tengrui Yang ,&nbsp;Beichen Yu ,&nbsp;Lingxiao Yin ,&nbsp;Xiaojiang Wen ,&nbsp;Zhaoxi Long ,&nbsp;Mingjun Jiang","doi":"10.1016/j.powtec.2025.121350","DOIUrl":"10.1016/j.powtec.2025.121350","url":null,"abstract":"<div><div>Expanding the range of water jet crushing gas-containing coal is an important basis for improving the effectiveness of deep coalbed methane extraction based on hydraulic jet cavity completion. Currently, the understanding of the damage evolution and crushing mechanism of gas-containing coal under water jet impact loading is not deep enough, which limits the optimization of water jet reservoir remodeling technology. In this paper, a multi-physical field coupling model of gas-containing coal under water jet impact loading was established, the crushing mechanism of gas-containing coal under water jet impact loading was investigated, and the parameter adjustment optimization strategy for enhancing the coal-breaking efficiency was explored. The results show that the crushing of gas-containing coal under loading is dominated by tensile stress, the development of fractures in the tensile damage region will lead to the fragmentation of coal to form a small fragment belt, and when the fractures are fully developed, the non-damage region encapsulated by the belt will be stripped from the coal surface in its entirety, and the coal with higher gas pressure or smaller Poisson's ratio has a larger damage region and higher crushing degree. In addition, increasing the jet nozzle radius has the best effect to improve the effective breaking depth; increasing the jet pressure enhances the coal-breaking degree while changing the jet diffusion angle and jet nozzle radius have less effect. The research results have been verified by engineering application results, which can provide theoretical guidance for improving the efficiency of deep coalbed methane development.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"465 ","pages":"Article 121350"},"PeriodicalIF":4.5,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144623562","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":"Analysis of particle stratification in vibratory screening: Insights from DEM simulations","authors":"Soni Jaiswal ,&nbsp;Arijit Chakrabarty ,&nbsp;Arnab Atta ,&nbsp;Samik Nag","doi":"10.1016/j.powtec.2025.121374","DOIUrl":"10.1016/j.powtec.2025.121374","url":null,"abstract":"<div><div>The screening process involves two key mechanisms: particle stratification and passage of free particles through apertures. Efficient separation relies on high stratification rates, where fine particles percolate to the bottom of the bed, and larger particles rise to the top. These processes vary along the screen length, with fine particles typically passing through the screen earlier. Vibration conditions (motion type, frequency, amplitude), feed rate, and material properties significantly influence this behavior. In this study, particle bed structure and stratification patterns were analyzed under various screening conditions using DEM simulations. The DEM model was validated using a laboratory-scale setup based on partition curves and cut-size (d₅₀). The study examined the effects of three vibration modes (linear, circular, elliptical) along with vibration frequency, amplitude, feed rate, and material characteristics. The results show distinct stratification patterns for each vibration mode. Elliptical and circular motions performed best for near-mesh particles, while linear motion was most effective for fine particle sieving. These findings offer valuable insights for optimizing screening parameters based on feed characteristics. This will help in improved design, and better selection of parameters for screening of bulk materials.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"465 ","pages":"Article 121374"},"PeriodicalIF":4.5,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144656374","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":"Numerical study of wide continuous particle size distribution effect on the transient supersonic gas-solid jet","authors":"Xiao Mo ,&nbsp;Yang Xiao ,&nbsp;Kaixiong Qing ,&nbsp;Hongshi Yu","doi":"10.1016/j.powtec.2025.121372","DOIUrl":"10.1016/j.powtec.2025.121372","url":null,"abstract":"<div><div>Supersonic gas-powder flows find widespread utilization in industrial process, but the impact of non-uniform particle dimensions on the transient delivery characteristics has not been fully studied. In this research, the discrete phase method (DPM) based on the Euler-Lagrangian approach was adopted to study supersonic gas-powder flow within a Laval nozzle. After validating mathematical models based on empirical data, the effect of particle size distribution (PSD) on gas phase compressibility, particle velocity, particle temperature and interphase interactions were focused. The findings reveal that particles reach the nozzle outlet within an average time of 250 μs, with a total injection duration ranging from 250 μs to 1 ms, highlighting notable transient properties. A wider PSD indicates a larger percentage of tiny particles, making them more susceptible to gas velocity and temperature. Consequently, these particles exhibit higher velocities and lower temperatures. Quantitatively, at 85 mm downstream from the nozzle, particles can achieve a mean velocity of 1050 m/s and a mean temperatures of 160 K. Moreover, a wider PSD correlates with a larger velocity standard deviation, indicating more uneven particle acceleration. Finally, the momentum and energy exchange between phases predominantly occur in the convergence and divergence sections of the nozzle. These discoveries present valuable insights into supersonic transient gas-powder flow and provide reference for the design and optimization of such equipment.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"465 ","pages":"Article 121372"},"PeriodicalIF":4.5,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144656372","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}