Yurui Wang , Zhenbo Tong , Hak-Kim Chan , Runyu Yang
{"title":"DEM study of the effect of contact electrification on the flowability of pharmaceutical fine powders","authors":"Yurui Wang , Zhenbo Tong , Hak-Kim Chan , Runyu Yang","doi":"10.1016/j.apt.2025.104990","DOIUrl":"10.1016/j.apt.2025.104990","url":null,"abstract":"<div><div>Electrostatic charge generated through contact electrification plays a key role in determining the flowability of pharmaceutical fine powders. This study investigated these electrostatic effects using a discrete element method (DEM) simulation that integrates a dynamic charge transfer model and an electrostatic interaction model. The model was validated by comparing its predictions with literature data and FT4 experimental results for charge accumulation and flowability. Simulations revealed that charge transfer predominantly occurs at particle–wall contacts due to differences in work function, leading to a higher charge level on particles near the walls, which then transfer charges to other particles upon contact. Repulsive electrostatic forces were found to reduce particle cohesion, thereby improving flowability, whereas strong attractive image forces between particles and walls caused significant adhesion. The study also explored the effects of work function differences between particles and walls, as well as operating conditions in FT4 tests. Results indicated that the specific charge of particles exhibited a linear relationship with the particle–wall work function difference and the blade penetration depth, but a non-linear relationship with blade tip speed and helix angle. Finally, a universal relation was proposed to predict specific charge and electrostatic forces under various conditions, offering a straightforward method for optimizing powder handling processes.</div></div>","PeriodicalId":7232,"journal":{"name":"Advanced Powder Technology","volume":"36 9","pages":"Article 104990"},"PeriodicalIF":4.2,"publicationDate":"2025-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144557197","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":"Effective method to prevent heaping caused by particle convection in vertically vibrated beds","authors":"Satoru Matsuda, Koji Kuramoto","doi":"10.1016/j.apt.2025.104987","DOIUrl":"10.1016/j.apt.2025.104987","url":null,"abstract":"<div><div>A simpler approach is required to prevent heaping caused by particle convection in a vertically vibrated bed from the viewpoint of reaction efficiency. Particle convection under vibration is investigated experimentally and can be successfully explained by simulations using Discrete Element Method (DEM). It is observed that the downward flow occurs near the walls, and the upward flow occurs away from them. Thus, the walls significantly affect particle convection. Effective control methods that use internal structures with walls have been proposed and investigated. In order to prevent heaping, it is effective to place the internal structure with walls at the location where the particles would inherently be heaping up. The standard deviations of particle bed surface height become small when internals are placed, which means the heaping is suppressed.</div></div>","PeriodicalId":7232,"journal":{"name":"Advanced Powder Technology","volume":"36 9","pages":"Article 104987"},"PeriodicalIF":4.2,"publicationDate":"2025-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144548584","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":"Control of temperature rise during wet stirred media milling","authors":"Hamidreza Heidari , Alejandro Vargas , Adriana Macris , Frank Muller , Oliver Pikhard , Gulenay Guner , Donald.J. Clancy , Ecevit Bilgili","doi":"10.1016/j.apt.2025.104981","DOIUrl":"10.1016/j.apt.2025.104981","url":null,"abstract":"<div><div>Temperature increases during wet stirred media milling (WSMM) significantly, which may cause degradation of thermolabile drugs. This study aims to examine the impacts of batch size, pre-cooling, and cooling rate on product temperature under various milling conditions. To this end, a lab-scale mill was used along with a small batch (∼0.22 L) and a large batch (∼5.4 L) of CaCO<sub>3</sub> suspension. For the 5.4 L batches, the impacts of stirrer speed and bead loading–size on particle size and temperature were investigated experimentally and simulated by an enthalpy balance model (EBM). Our results suggest that the median size was lower (median size <em>x</em><sub>50</sub> as low as 0.227 µm), and the temperature was higher (with the maximum temperature rise of 27 °C) at the higher stirrer speed with a higher bead loading, whereas the bead size impact was weak. The temperature rise was 4–8 °C lower for the smaller batch than for the larger batch. Besides predicting the milling parameters’ impacts, the EBM suggests that lowering coolant temperature was the most effective to control product temperature, whereas a low suspension flow rate could be detrimental, and pre-cooling had limited favorable impact. Overall, we conclude that batch size, coolant temperature, pre-cooling, and suspension flow rate can be adjusted, as guided by EBM, to control temperature during WSMM. These findings offer practical guidance for controlling thermal conditions in WSMM and improving scalability and product quality in pharmaceutical manufacturing.</div></div>","PeriodicalId":7232,"journal":{"name":"Advanced Powder Technology","volume":"36 9","pages":"Article 104981"},"PeriodicalIF":4.2,"publicationDate":"2025-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144548585","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}
Weidong He , Yinghe Guo , Jingxian Liu , Xiaotong Zhou , Longji Hu , Keyi He , Xiuli Lin
{"title":"Experimental and numerical Investigation of fine particle emissions from damaged Membrane-Coated filter bag","authors":"Weidong He , Yinghe Guo , Jingxian Liu , Xiaotong Zhou , Longji Hu , Keyi He , Xiuli Lin","doi":"10.1016/j.apt.2025.104985","DOIUrl":"10.1016/j.apt.2025.104985","url":null,"abstract":"<div><div>Baghouses equipped with Polytetrafluoroethylene (PTFE) membrane-coated filter bags are effective in controlling industrial dust. However, the PTFE membrane is prone to physical damage during filter bag production, leading to significant particle leakage from the damaged areas. In this study, a model was developed to assess the impact of membrane damage on the emission of industrial process particles. The particle concentration downstream of the filter bag can be calculated by inputting various parameters, including the membrane failure area, filtration efficiency, and filtration velocity distribution, into the model. Incorporating numerically simulated axial airflow distribution data substantially improved the model accuracy. The model validation was conducted using full-scale PTFE membrane-coated filter bags. Results indicated that the model achieved accurate predictions of particulate emission concentrations (0.3–5 μm size range) for cases involving membrane damage. Additionally, the duration of the effect of membrane damage on emissions during particle loading was evaluated.</div></div>","PeriodicalId":7232,"journal":{"name":"Advanced Powder Technology","volume":"36 8","pages":"Article 104985"},"PeriodicalIF":4.2,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144524319","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}
Alireza Tamimzadeh , Atoosa Dodelehband , Ariya Gordanshekan , Shakiba Arabian , Reza Farahmand , Mehrdad Farhadian , Ali Reza Solaimany Nazar , Shahram Tangestaninejad
{"title":"A multifaceted investigation on photocatalytic performance of Bi2WO6/TiO2/ZIF-8: Adsorption, artificial neural networks, density functional theory, and antibacterial assessment studies","authors":"Alireza Tamimzadeh , Atoosa Dodelehband , Ariya Gordanshekan , Shakiba Arabian , Reza Farahmand , Mehrdad Farhadian , Ali Reza Solaimany Nazar , Shahram Tangestaninejad","doi":"10.1016/j.apt.2025.104984","DOIUrl":"10.1016/j.apt.2025.104984","url":null,"abstract":"<div><div>Bi<sub>2</sub>WO<sub>6</sub>/TiO<sub>2</sub>/ZIF-8 photocatalytic degradation and antibacterial toxicity of degraded methylene blue were studied in this paper. The optimum mass ratio of ZIF-8 to Bi<sub>2</sub>WO<sub>6</sub>/TiO<sub>2</sub> was determined via comprehensive investigation through photocatalytic experiments, and morphological, structural, and photoelectrochemical characterizations. Operating conditions like initial pH, photocatalyst dosage, initial pollutant concentration, and light intensity were examined. The results were modeled by artificial neural networks, and optimization of operating conditions was performed by a genetic algorithm (GA). The GA optimized a cost function expressed as the ratio of the catalyst consumed to the pollutant degraded (mg/g). This optimization computed optimum conditions as pH of 8.41, photocatalyst dosage of 0.05 g/L, dye concentration of 50 ppm, and light intensity of ∼ 580 W/m<sup>2</sup> for 99.9 % removal efficiency at 360 min. Experimentally, 935 mg/g removal with ¬93.5 % removal efficiency was obtained. To study the toxicity of degraded solution, LC-MS analysis coupled with density functional theory and quantitative-structure activity relationship indicated that by-products became more toxic than the initial contaminant, representing the necessity of complete removal of the organic dye before releasing to the environment. Gram-positive (<em>Staphylococcus aureus</em>) and gram-negative (<em>Klebsiella pneumoniae</em>) bacteria were determined, and the minimum inhibitory concentration was not achieved for the degraded solution.</div></div>","PeriodicalId":7232,"journal":{"name":"Advanced Powder Technology","volume":"36 8","pages":"Article 104984"},"PeriodicalIF":4.2,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144524318","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":"On the phenomenon of shear wave velocity faster than that of compression wave induced by particle shape","authors":"Chengbo Li , Peng Zhang , Lin Bao , Chuang Zhao","doi":"10.1016/j.apt.2025.104974","DOIUrl":"10.1016/j.apt.2025.104974","url":null,"abstract":"<div><div>This study provides a series of ellipsoidal aggregates in which the shear wave travels faster than the compressional one as the shape becomes more oblate. The propagation of elastic wave is simulated by the discrete element method, and the velocity is calculated by the time-of-flight method. An increase in the aspect ratio <em>α</em> leads to a significant reduction in the velocities of both compression (P) and shear (S) waves. As <span><math><mrow><mi>α</mi><mo><</mo><mn>6</mn></mrow></math></span>, the compression wave velocity is bigger than the shear wave velocity. However, when <span><math><mrow><mi>α</mi><mo>></mo><mn>6</mn></mrow></math></span>, the shear wave velocity becomes the faster one. According to the anisotropy coefficients of different ellipsoidal assemblies, the phenomenon of a faster shear wave is explained, and the equivalent propagation direction is also calculated. It is not that the shape induces a larger shear modulus, but rather that the variation in shape causes elastic waves to preferentially propagate along specific contact points, where the contact normals are similarly oriented. This normal vector is referred to as the equivalent propagation direction. As <span><math><mrow><mi>α</mi></mrow></math></span> increases, the equivalent propagation direction of the shear wave becomes more aligned with the vertical (height) direction of the sample, whereas the direction of the compression wave changes less significantly and tends to stabilize. A closer direction implies a shorter propagation path and a faster velocity. This study demonstrates a distinctive acoustic property induced by shape, which provides references for probing the interior structure of granular material by elastic waves. It also gives an idea to construct material in which wave can propagate along the designated path.</div></div>","PeriodicalId":7232,"journal":{"name":"Advanced Powder Technology","volume":"36 8","pages":"Article 104974"},"PeriodicalIF":4.2,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144502795","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}
Pengcheng Li , Gang Pan , Lianjun Chen , Siyuan Zhang , Rongmin Zhang
{"title":"Research on discrete element construction and parameter calibration of agglomerated particles in moist-mix shotcrete","authors":"Pengcheng Li , Gang Pan , Lianjun Chen , Siyuan Zhang , Rongmin Zhang","doi":"10.1016/j.apt.2025.104971","DOIUrl":"10.1016/j.apt.2025.104971","url":null,"abstract":"<div><div>The purpose of this paper is to achieve the discrete element construction and contact parameter calibration of agglomerated particles in moist-mix shotcrete. The morphological characteristics and particle size distribution of Mortar-group particles (Mgp) and Aggregate-agglomerates (Aa) under different water-cement ratios are measured, the discrete element parameters of agglomerated particles and discrete element construction of various forms of particle models are clarified, and the optimal combination of contact parameters of agglomerated particles in different experimental groups are screened. The results show that the significant influencing parameters of repose angle of concrete materials under different water-cement ratios are obtained, and the second-order regression model is established between repose angle and significant parameters. The optimal combination of four significant parameters when the water-cement ratio is 0.25: the rolling friction coefficient of Mgp-Mgp is 0.15, the surface energy of Mgp-Mgp is 0.96 J<strong>·</strong>m<sup>−2</sup>, the static friction coefficient of Mgp-SP (Steel plane) is 0.56, and the surface energy of Aa-Aa is 2.30 J·m<sup>−2</sup>. The relative errors of average repose angles between simulation and actual physical experiments are about 2.0 %. Validation test results indicate that the discrete element construction and contact parameter combination of agglomerated particles have strong reliability, which can provide a basis for particle model construction and contact parameter support for long-distance pneumatic conveying characteristics of moist-mix shotcrete.</div></div>","PeriodicalId":7232,"journal":{"name":"Advanced Powder Technology","volume":"36 8","pages":"Article 104971"},"PeriodicalIF":4.2,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144502796","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}
Xiaopan Wu , Wei Pan , Chunming Zheng , Dan Wang , Chunlei Wan , Yixiang Ou , Yi Feng , Qili Jiang , Haoqi Wang , Zhiqiang Che , Yue Zhang , Li Hou , Wenping Yuan
{"title":"Effect of ball milling on the surface chemical state of Al2O3 powders","authors":"Xiaopan Wu , Wei Pan , Chunming Zheng , Dan Wang , Chunlei Wan , Yixiang Ou , Yi Feng , Qili Jiang , Haoqi Wang , Zhiqiang Che , Yue Zhang , Li Hou , Wenping Yuan","doi":"10.1016/j.apt.2025.104978","DOIUrl":"10.1016/j.apt.2025.104978","url":null,"abstract":"<div><div>The present study investigates the effect of ball milling on the surface chemical state of 500 nm Al<sub>2</sub>O<sub>3</sub> powders to enable low-temperature sintering of high-performance ceramics. FTIR spectra reveal Al-OH absorption peaks. Specifically, with increasing ball milling time, the amount of stable [AlO<sub>6</sub>] groups and Al-O bonds decreases, while that of metastable [AlO<sub>4</sub>] groups and Al-O–H bonds increases, as revealed by deconvolution of XPS and Raman spectra. TEM observations confirm interparticle necking between the milled Al<sub>2</sub>O<sub>3</sub> particles, demonstrating the enhanced surface activation. Water adsorption isotherms at 298 K demonstrate higher adsorption capacity for activated powder than raw powder, with adsorption increasing with milling time. The optimal surface activation of the 500 nm Al<sub>2</sub>O<sub>3</sub> powder is achieved via 3 h ball milling at 600 rpm, featuring reduced particle size, increased BET surface area, and enhanced water adsorption. This mechanochemical activation enables low-temperature densification of electronic ceramics and optimization of pore structure in catalytic supports, offering a novel strategy for sustainable manufacturing of high-performance Al<sub>2</sub>O<sub>3</sub>-based ceramics.</div></div>","PeriodicalId":7232,"journal":{"name":"Advanced Powder Technology","volume":"36 8","pages":"Article 104978"},"PeriodicalIF":4.2,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144489892","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}
Qixuan Zhu , Yuqing Feng , Peter Witt , Warren Bruckard , Yaoyu Li , Runyu Yang
{"title":"A GPU-accelerated CFD-VOF-DEM approach for modelling the wet grinding process in a SAG mill and the mill speed effects","authors":"Qixuan Zhu , Yuqing Feng , Peter Witt , Warren Bruckard , Yaoyu Li , Runyu Yang","doi":"10.1016/j.apt.2025.104975","DOIUrl":"10.1016/j.apt.2025.104975","url":null,"abstract":"<div><div>Semi-autogenous grinding (SAG) mills are essential for cost-effective rock beneficiation, primarily utilizing wet milling processes. Although the milling process has been extensively studied by DEM modelling, the effect of slurry is frequently neglected due to its complex interactions with the charge. This paper presents an efficient CPU-GPU framework for CFD-DEM modelling of the gas–liquid-solid flows during the wet grinding in a 34′ SAG mill. The model, which adopts a VOF approach to simulate the free surface between gas and liquid slurry phase, was comprehensively validated across four different cases, including particle sedimentation, phase conservation, and particle dynamics in both dry and wet drums. The validated model was used to simulate multiphase interactions in a SAG mill at various rotation speeds.</div><div>The milling process stabilized after 20 s, with the bed showing a kidney shape, characterized by the cascading zone and cataracting stream. The slurry flow, enveloped by the particle bed, exhibited a strong recirculating flow following the particle trajectories. The inclusion of slurry resulted in weaker and fewer particle collisions, with the fluid force accounting for half of the total force acting on particles. The effect of the slurry on rock particles was greater than on ball particles due to the density difference. Power consumption mainly resulted from interactions between the lifter sides and particles, while the slurry consumed minimal power. Both collision energy and frequency significantly increased at higher mill speeds, which are also expected to cause more severe liner wear and increased power consumption.</div><div>The model provides an efficient framework for simulating dense particles interacting with multiple fluid phases. The findings elucidate the multiphase interaction mechanisms in the SAG mill and underscore the necessity of including slurry in simulations to accurately model the milling dynamics.</div></div>","PeriodicalId":7232,"journal":{"name":"Advanced Powder Technology","volume":"36 8","pages":"Article 104975"},"PeriodicalIF":4.2,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144489893","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":"Probing the improved collecting ability of dodecyl phosphate/poly-amine cation-anion association collector towards scheelite","authors":"Wei Chen , Qiqiao Liu , Jing Qi , Guangyi Liu","doi":"10.1016/j.apt.2025.104977","DOIUrl":"10.1016/j.apt.2025.104977","url":null,"abstract":"<div><div>Efficient flotation of scheelite is very important for the safety of tungsten resources. A brand new collector, i.e., cation–anion association, was designed by mixing potassium dodecyl phosphate (MAP-K) with amines including diethylenetriamine (DETA), triethylene tetramine (TETA) and tetraethylenepentamine (TEPA). The collecting performance of these cation–anion association collectors toward scheelite were systematically studied through micro-flotation, zeta potential, contact angle and adsorption capacity detection. The micro-flotation results implied that cation–anion association collector TTK (MAP-K and TETA at 2:1 M ratio) performed excellent collecting ability toward scheelite, and the recovery reached to 97.53% under concentration of 5.0×10<sup>−4</sup> mol/L TTK, while that was only 70.37% with MAP-K. It was found that the zeta potential of TTK-treated scheelite was positive shifted, implying that the amino group was protonated in cation–anion association of TTK. The positively charged TTK may have an electrostatic attraction of scheelite, facilitating the adsorption of phosphate groups in TTK on scheelite surface. The adsorption energy of the TTK (−11.082 eV) was nearly the twice that of MAP<sup>−</sup> (−5.072 eV). Therefore, DETA facilitated the adsorption of MAP-K on scheelite and strengthened the hydrophobicity of scheelite.</div></div>","PeriodicalId":7232,"journal":{"name":"Advanced Powder Technology","volume":"36 8","pages":"Article 104977"},"PeriodicalIF":4.2,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144470704","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}