Pub Date : 2025-12-27DOI: 10.1016/j.powtec.2025.122084
Lujia Zhang, Zhengyu Hou, Miaosen Yu, Zhe Zhang
Triboelectric charging is a common issue in chute transportation of granular materials, leading to problems such as particles adhesion, blockage and discharge. In this work, we focus on the triboelectric charging of granular materials influenced by chute parameters and surface strain, and further reveal the underlying physical mechanisms. Parameters including sliding length, chute angle, vibration, and applied voltage are investigated for their impact on the triboelectric charging of various materials. Additionally, the influences of chute surface strain both on magnitude and direction are examined. Experimental results show that sliding length has a positive correlation with triboelectrification, while inclined angle exhibits a nonlinear relationship with the charge of PP particles. As the chute vibration frequency increases from 0 to 88.8 Hz, the particle charge rises from −20.55 nC to −38.52 nC. It is worth noting that, applying negative voltage to the chute significantly increases the particle charge, with glass beads showing a linear relation of 21.46 nC/kV. It is also found that surface strain strongly influences particle charging, governed by both magnitude and direction. Confocal microscopy reveals that this effect arises from changes in contact area, surface morphology, and particle motion. These results allow comparison of triboelectric charging of granular materials under different chute parameters, providing an experimental reference for reducing charging in industrial applications.
{"title":"Experimental study on triboelectric charging of granular materials influenced by chute parameters and surface strain","authors":"Lujia Zhang, Zhengyu Hou, Miaosen Yu, Zhe Zhang","doi":"10.1016/j.powtec.2025.122084","DOIUrl":"10.1016/j.powtec.2025.122084","url":null,"abstract":"<div><div>Triboelectric charging is a common issue in chute transportation of granular materials, leading to problems such as particles adhesion, blockage and discharge. In this work, we focus on the triboelectric charging of granular materials influenced by chute parameters and surface strain, and further reveal the underlying physical mechanisms. Parameters including sliding length, chute angle, vibration, and applied voltage are investigated for their impact on the triboelectric charging of various materials. Additionally, the influences of chute surface strain both on magnitude and direction are examined. Experimental results show that sliding length has a positive correlation with triboelectrification, while inclined angle exhibits a nonlinear relationship with the charge of PP particles. As the chute vibration frequency increases from 0 to 88.8 Hz, the particle charge rises from −20.55 nC to −38.52 nC. It is worth noting that, applying negative voltage to the chute significantly increases the particle charge, with glass beads showing a linear relation of 21.46 nC/kV. It is also found that surface strain strongly influences particle charging, governed by both magnitude and direction. Confocal microscopy reveals that this effect arises from changes in contact area, surface morphology, and particle motion. These results allow comparison of triboelectric charging of granular materials under different chute parameters, providing an experimental reference for reducing charging in industrial applications.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"471 ","pages":"Article 122084"},"PeriodicalIF":4.6,"publicationDate":"2025-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145882540","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 : 2025-12-27DOI: 10.1016/j.powtec.2025.122056
Yunhai Liu, Jiawei Xie
This study proposes a novel multiscale coupled approach integrating computational fluid dynamics and molecular dynamics to enhance the erosion resistance of WC cemented carbide throttling valves. Macroscopic analysis of three valve types (cage, cylinder, wedge) revealed that the cylindrical valve exhibits the lowest erosion rate, while the wedge valve suffers the most severe erosion due to changes in the flow path. Particle motion analysis shows that multi-angle impacts of solid particles are the primary erosion mechanism. Based on this insight, microscopic studies of WC crystallographic planes were conducted, with the (111) plane demonstrating the best erosion resistance and the (110) plane exhibiting excellent plastic recovery. This method provides essential guidance for valve structure optimization and wear-resistant material design.
{"title":"Multiscale CFD-MD coupled investigation of dynamic erosion behavior in throttling valves and the microstructural response of WC materials","authors":"Yunhai Liu, Jiawei Xie","doi":"10.1016/j.powtec.2025.122056","DOIUrl":"10.1016/j.powtec.2025.122056","url":null,"abstract":"<div><div>This study proposes a novel multiscale coupled approach integrating computational fluid dynamics and molecular dynamics to enhance the erosion resistance of WC cemented carbide throttling valves. Macroscopic analysis of three valve types (cage, cylinder, wedge) revealed that the cylindrical valve exhibits the lowest erosion rate, while the wedge valve suffers the most severe erosion due to changes in the flow path. Particle motion analysis shows that multi-angle impacts of solid particles are the primary erosion mechanism. Based on this insight, microscopic studies of WC crystallographic planes were conducted, with the (111) plane demonstrating the best erosion resistance and the (110) plane exhibiting excellent plastic recovery. This method provides essential guidance for valve structure optimization and wear-resistant material design.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"471 ","pages":"Article 122056"},"PeriodicalIF":4.6,"publicationDate":"2025-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145882463","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 : 2025-12-26DOI: 10.1016/j.powtec.2025.122076
Alix M. Ehlers , David J. Bunin , Mark J. Caddick , Jim Loebig , Rory Clarkson
Test dusts serve as analogs of atmospheric mineral dusts in a wide variety of scientific and engineering applications in which knowledge of their chemical and physical properties is essential. The Arizona Test Dust (ATD) is widely used in the aviation, automotive, and filtration industries. It contains a complex mineral assemblage, with discrepancies between previous reports of its mineral constituents and their abundances, and little prior description of the morphology of its particles. MIL-E-5007C (C-SPEC) is a chemically simpler dust consisting almost entirely of crushed quartz, but its particle morphologies are again poorly quantified. This work resolves many of these inconsistencies by using multiple complementary analytical techniques to describe the mineralogy and physical properties of ATD and C-SPEC. We find that all grades of ATD contain quartz, several minerals from the feldspar group, calcite, hornblende, and the sheet silicates kaolinite, an illite-smectite mixed clay phase, smectite, glauconite, and biotite. Iron oxide phases (possibly hematite) are also present. All analyzed particles are crystalline, with no evidence of amorphous phases. Despite consistent mineral identities between all analyzed ATD batches, mineral abundances are grain-size dependent, with coarser grades quartz-rich and clay-poor, and finer grades clay-rich and quartz-poor. Particle shape analyses demonstrate a higher average sphericity in ATD particles than C-SPEC particles. This leads to potentially very different erosive potentials of different ATD grades and C-SPEC in engine testing applications and substantial variation in the likelihood of chemical interactions between each of these dusts and engineered or natural systems.
{"title":"On the composition of the Arizona test dust: A comprehensive characterization of an analog for atmospheric mineral dust","authors":"Alix M. Ehlers , David J. Bunin , Mark J. Caddick , Jim Loebig , Rory Clarkson","doi":"10.1016/j.powtec.2025.122076","DOIUrl":"10.1016/j.powtec.2025.122076","url":null,"abstract":"<div><div>Test dusts serve as analogs of atmospheric mineral dusts in a wide variety of scientific and engineering applications in which knowledge of their chemical and physical properties is essential. The Arizona Test Dust (ATD) is widely used in the aviation, automotive, and filtration industries. It contains a complex mineral assemblage, with discrepancies between previous reports of its mineral constituents and their abundances, and little prior description of the morphology of its particles. MIL-E-5007C (C-SPEC) is a chemically simpler dust consisting almost entirely of crushed quartz, but its particle morphologies are again poorly quantified. This work resolves many of these inconsistencies by using multiple complementary analytical techniques to describe the mineralogy and physical properties of ATD and C-SPEC. We find that all grades of ATD contain quartz, several minerals from the feldspar group, calcite, hornblende, and the sheet silicates kaolinite, an illite-smectite mixed clay phase, smectite, glauconite, and biotite. Iron oxide phases (possibly hematite) are also present. All analyzed particles are crystalline, with no evidence of amorphous phases. Despite consistent mineral identities between all analyzed ATD batches, mineral abundances are grain-size dependent, with coarser grades quartz-rich and clay-poor, and finer grades clay-rich and quartz-poor. Particle shape analyses demonstrate a higher average sphericity in ATD particles than C-SPEC particles. This leads to potentially very different erosive potentials of different ATD grades and C-SPEC in engine testing applications and substantial variation in the likelihood of chemical interactions between each of these dusts and engineered or natural systems.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"471 ","pages":"Article 122076"},"PeriodicalIF":4.6,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145882537","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 : 2025-12-26DOI: 10.1016/j.powtec.2025.122079
Tao Shuang , Zhang Tian , Ge Shaocheng , Li Sheng , Tong Linquan , Guo Yuhao , Chen Xingyu
Pneumatic spray dust reduction technology is widely used in dust pollution control in the coal industry due to its advantages of high spray concentration, small droplet size, and fast movement speed. However, supersonic power spray dust reduction will be accompanied by severe high-frequency noise, which restricts the promotion of technology. To address this problem, this research develops a multi-material composite sound-absorbing device adapted to the high-frequency noise of supersonic power spray. It uses multi-field coupling simulations and experiments such as high Mach number and pressure acoustics to explore the noise characteristics of single- and multi-layer sound-absorbing chambers, verify the feasibility of the device, screen the optimal structure, and reveal the noise reduction mechanism. Research shows that the flow field velocity of the Laval nozzle in single- and multi-layer sound-absorbing chambers decreases outward along the central axis, and the flow field velocity inside the multi-layer chamber is even lower; the core area where sound energy is converted into heat energy is the sound-absorbing material in the inner layer near the nozzle. The three-dimensional network micropores of the porous fiber material can convert sound energy into heat energy and dissipate it, greatly reducing the sound pressure level of radial propagation. In a single-layer chamber, the noise reduction effect is optimal when the cavity diameter is 56 mm. The sound pressure level at the sound source is reduced by 10.9 % ∼ 13.4 %, and the sound radiation direction is reduced by 7.3 % ∼ 10.8 %. Under different materials, airgel has the best noise reduction effect, with corresponding reductions of 13.4 % and 10.8 %. Among the multi-layer chambers, composite method 5 has the best noise reduction effect, with a 21.2 % reduction at the sound source and a 12.4 % reduction in the sound radiation direction, which is better than the single-layer airgel chamber. When the aerodynamic pressure increases, the sound pressure level in each frequency band increases, and when the water flow increases, the sound pressure level in the middle and high frequency bands decreases. Under the same working conditions, the particle size of 50 % of the droplets is about 11 μm, and the dust reduction efficiency exceeds 88 % in 3 min. This study not only ensures the efficiency of atomization and dust reduction, but also reduces the high-frequency noise at the sound source to below the national standard (GB12348–2008) 85 dB, laying a theoretical and technical foundation for the collaborative control of dust and spray noise.
{"title":"Research on noise reduction performance of supersonic power spraying based on multimaterial composite sound absorption","authors":"Tao Shuang , Zhang Tian , Ge Shaocheng , Li Sheng , Tong Linquan , Guo Yuhao , Chen Xingyu","doi":"10.1016/j.powtec.2025.122079","DOIUrl":"10.1016/j.powtec.2025.122079","url":null,"abstract":"<div><div>Pneumatic spray dust reduction technology is widely used in dust pollution control in the coal industry due to its advantages of high spray concentration, small droplet size, and fast movement speed. However, supersonic power spray dust reduction will be accompanied by severe high-frequency noise, which restricts the promotion of technology. To address this problem, this research develops a multi-material composite sound-absorbing device adapted to the high-frequency noise of supersonic power spray. It uses multi-field coupling simulations and experiments such as high Mach number and pressure acoustics to explore the noise characteristics of single- and multi-layer sound-absorbing chambers, verify the feasibility of the device, screen the optimal structure, and reveal the noise reduction mechanism. Research shows that the flow field velocity of the Laval nozzle in single- and multi-layer sound-absorbing chambers decreases outward along the central axis, and the flow field velocity inside the multi-layer chamber is even lower; the core area where sound energy is converted into heat energy is the sound-absorbing material in the inner layer near the nozzle. The three-dimensional network micropores of the porous fiber material can convert sound energy into heat energy and dissipate it, greatly reducing the sound pressure level of radial propagation. In a single-layer chamber, the noise reduction effect is optimal when the cavity diameter is 56 mm. The sound pressure level at the sound source is reduced by 10.9 % ∼ 13.4 %, and the sound radiation direction is reduced by 7.3 % ∼ 10.8 %. Under different materials, airgel has the best noise reduction effect, with corresponding reductions of 13.4 % and 10.8 %. Among the multi-layer chambers, composite method 5 has the best noise reduction effect, with a 21.2 % reduction at the sound source and a 12.4 % reduction in the sound radiation direction, which is better than the single-layer airgel chamber. When the aerodynamic pressure increases, the sound pressure level in each frequency band increases, and when the water flow increases, the sound pressure level in the middle and high frequency bands decreases. Under the same working conditions, the particle size of 50 % of the droplets is about 11 μm, and the dust reduction efficiency exceeds 88 % in 3 min. This study not only ensures the efficiency of atomization and dust reduction, but also reduces the high-frequency noise at the sound source to below the national standard (GB12348–2008) 85 dB, laying a theoretical and technical foundation for the collaborative control of dust and spray noise.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"471 ","pages":"Article 122079"},"PeriodicalIF":4.6,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145882543","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 : 2025-12-26DOI: 10.1016/j.powtec.2025.122080
Zhiyang Shang , Jie Peng , Jiahui Tang , Renjie Wei , Zhao Jiang , Di Dai
Microbially induced calcium carbonate precipitation (MICP) technology is often limited in practical applications due to low mineralization efficiency and uneven precipitate distribution. The root cause lies in the lack of effective control over the crystalline polymorphs and morphology of calcium carbonate. This study proposes a microstructural regulation strategy using sodium carboxymethyl cellulose (CMCNa) as a biopolymer additive to guide the crystallization pathway and spatial distribution of calcium carbonate. Solution tests and sand column tests, combined with multi-scale characterization (XRD, SEM, MIP), demonstrated that CMCNa, through carboxyl‑calcium ion complexation, increased the precipitate mass by a 225 % and successfully shifted the dominant crystalline phase from calcite to vaterite (vaterite content: 83.6 % vs. 12.4 % in the control). More importantly, quantitative pore structure analysis revealed that in the presence of CMCNa, newly formed crystals preferentially fill the 50–100 μm pores and develop into a polyhedral, multi-point cementation structure. This structure enables the coating of sand grains and enlarges the contact area between particles. At the optimal dosage, the unconfined compressive strength of the treated sand column reached 2667 kPa, a 703 % increase over the control group (332 kPa). This study demonstrates that CMC-Na is an efficient MICP modifier. This approach of actively regulating the microstructure of the cementing phase provides a new strategy for achieving high-performance biogeotechnical cementation and sustainable ground improvement.
{"title":"Microstructural regulation mechanism of MICP: Using CMC-Na to promote vaterite and targeted pore filling for enhanced sand strength","authors":"Zhiyang Shang , Jie Peng , Jiahui Tang , Renjie Wei , Zhao Jiang , Di Dai","doi":"10.1016/j.powtec.2025.122080","DOIUrl":"10.1016/j.powtec.2025.122080","url":null,"abstract":"<div><div>Microbially induced calcium carbonate precipitation (MICP) technology is often limited in practical applications due to low mineralization efficiency and uneven precipitate distribution. The root cause lies in the lack of effective control over the crystalline polymorphs and morphology of calcium carbonate. This study proposes a microstructural regulation strategy using sodium carboxymethyl cellulose (CMC<img>Na) as a biopolymer additive to guide the crystallization pathway and spatial distribution of calcium carbonate. Solution tests and sand column tests, combined with multi-scale characterization (XRD, SEM, MIP), demonstrated that CMC<img>Na, through carboxyl‑calcium ion complexation, increased the precipitate mass by a 225 % and successfully shifted the dominant crystalline phase from calcite to vaterite (vaterite content: 83.6 % vs. 12.4 % in the control). More importantly, quantitative pore structure analysis revealed that in the presence of CMC<img>Na, newly formed crystals preferentially fill the 50–100 μm pores and develop into a polyhedral, multi-point cementation structure. This structure enables the coating of sand grains and enlarges the contact area between particles. At the optimal dosage, the unconfined compressive strength of the treated sand column reached 2667 kPa, a 703 % increase over the control group (332 kPa). This study demonstrates that CMC-Na is an efficient MICP modifier. This approach of actively regulating the microstructure of the cementing phase provides a new strategy for achieving high-performance biogeotechnical cementation and sustainable ground improvement.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"471 ","pages":"Article 122080"},"PeriodicalIF":4.6,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145882459","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 : 2025-12-26DOI: 10.1016/j.powtec.2025.122071
Jun Li , Siyuan He , Xu Han , Mingyi Wu , Zongyan Zhou
The proper proppant placement in complex fractures is significant in improving the production of unconventional reservoirs. In the past, many studies assumed that the fractures have smooth surfaces, without considering the effect of the surface roughness on the proppant transportation and deposition in complex fracture models. In this work, a realistic complex fracture model with rough surface is considered. The fracture model with rough surface consists of a primary fracture and a secondary fracture with an obtuse-angle bend of 120°. Meanwhile, the differences of proppant transport laws between rough and smooth fractures are studied in depth. The experimental results show that for the low pump rate (below 83 mL/s), the roughness does not affect the proppant distribution much in the fracture. However, higher pump rate (e.g., more than 83 mL/s) can result in large empty areas in the primary fracture. To solve this problem, larger proppant with a low pump rate should be injected to effectively fill in the empty area. In the secondary fracture, the roughness can increase the proppant transportation efficiency. The experimental findings are useful to understanding the proppant transportation and deposition efficiency in complex fractures with rough surfaces.
{"title":"Experimental studies of the proppant transportation and deposition in the complex-fracture with rough surfaces","authors":"Jun Li , Siyuan He , Xu Han , Mingyi Wu , Zongyan Zhou","doi":"10.1016/j.powtec.2025.122071","DOIUrl":"10.1016/j.powtec.2025.122071","url":null,"abstract":"<div><div>The proper proppant placement in complex fractures is significant in improving the production of unconventional reservoirs. In the past, many studies assumed that the fractures have smooth surfaces, without considering the effect of the surface roughness on the proppant transportation and deposition in complex fracture models. In this work, a realistic complex fracture model with rough surface is considered. The fracture model with rough surface consists of a primary fracture and a secondary fracture with an obtuse-angle bend of 120°. Meanwhile, the differences of proppant transport laws between rough and smooth fractures are studied in depth. The experimental results show that for the low pump rate (below 83 mL/s), the roughness does not affect the proppant distribution much in the fracture. However, higher pump rate (e.g., more than 83 mL/s) can result in large empty areas in the primary fracture. To solve this problem, larger proppant with a low pump rate should be injected to effectively fill in the empty area. In the secondary fracture, the roughness can increase the proppant transportation efficiency. The experimental findings are useful to understanding the proppant transportation and deposition efficiency in complex fractures with rough surfaces.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"471 ","pages":"Article 122071"},"PeriodicalIF":4.6,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922467","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 : 2025-12-26DOI: 10.1016/j.powtec.2025.122077
Liang Cao, Yongjun Peng
Efficient dewatering of fine particulate suspensions remains a critical challenge in powder processing and slurry handling. Although polymer flocculants are widely used to promote particle aggregation, their effects on mechanical dewatering, particularly the contrasting responses of centrifugation and filtration, are not fully understood. This study systematically investigates the influence of an anionic polyacrylamide (AN934SH) at varying dosages on dewatering efficiency, slurry rheology, and cake consolidation. At low to moderate dosages (0–50 g/t), floc growth and enhanced permeability improved water removal in both centrifugation and filtration, reducing moisture from 37.3 % to 35.3 % in centrifugation and from 36.0 % to 35.8 % in filtration, with centrifugation exhibiting a more pronounced improvement. At higher dosages (200 g/t), however, centrifugation efficiency declined sharply to 41.2 % moisture, whereas filtration performance decreased less and remained comparatively stable (39.8 %). Higher dosages also produced denser, mechanically stronger cakes, with filter cakes exhibiting higher yield stress and viscoelastic moduli, whereas centrifuge cakes remained softer but more elastic. Mechanistic analysis indicates that these differences arise from the distinct force–viscosity relationships of the two dewatering methods: centrifugation is governed by a strong dependence of driving force/drag on viscosity, making it highly sensitive to viscosity-induced resistance, whereas filtration is buffered by pressure-driven compression and cake permeability. This work provides a unified framework linking flocculant dosage, particle aggregation, and cake properties, highlighting the fundamental differences in how centrifugation and filtration respond to flocculant dosing and offering guidance for optimizing dewatering strategies in powder processing.
{"title":"Differential dewatering responses to flocculant dosage in particulate slurries: Centrifugation versus filtration","authors":"Liang Cao, Yongjun Peng","doi":"10.1016/j.powtec.2025.122077","DOIUrl":"10.1016/j.powtec.2025.122077","url":null,"abstract":"<div><div>Efficient dewatering of fine particulate suspensions remains a critical challenge in powder processing and slurry handling. Although polymer flocculants are widely used to promote particle aggregation, their effects on mechanical dewatering, particularly the contrasting responses of centrifugation and filtration, are not fully understood. This study systematically investigates the influence of an anionic polyacrylamide (AN934SH) at varying dosages on dewatering efficiency, slurry rheology, and cake consolidation. At low to moderate dosages (0–50 g/t), floc growth and enhanced permeability improved water removal in both centrifugation and filtration, reducing moisture from 37.3 % to 35.3 % in centrifugation and from 36.0 % to 35.8 % in filtration, with centrifugation exhibiting a more pronounced improvement. At higher dosages (200 <em>g</em>/t), however, centrifugation efficiency declined sharply to 41.2 % moisture, whereas filtration performance decreased less and remained comparatively stable (39.8 %). Higher dosages also produced denser, mechanically stronger cakes, with filter cakes exhibiting higher yield stress and viscoelastic moduli, whereas centrifuge cakes remained softer but more elastic. Mechanistic analysis indicates that these differences arise from the distinct force–viscosity relationships of the two dewatering methods: centrifugation is governed by a strong dependence of driving force/drag on viscosity, making it highly sensitive to viscosity-induced resistance, whereas filtration is buffered by pressure-driven compression and cake permeability. This work provides a unified framework linking flocculant dosage, particle aggregation, and cake properties, highlighting the fundamental differences in how centrifugation and filtration respond to flocculant dosing and offering guidance for optimizing dewatering strategies in powder processing.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"471 ","pages":"Article 122077"},"PeriodicalIF":4.6,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145882458","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 : 2025-12-26DOI: 10.1016/j.powtec.2025.122074
Shuichang Liu , Zelin Zhong , Yong Zhang , Dongtao Wang , Zheng Cao , Kunyu Ye , Yi Chen
Drag models describe the interactions between particles and fluid, which directly affect the accuracy of liquid–solid two-phase flow simulations. To explore the applicability of different drag models in simulating the transport of particles in power-law fluids, this study investigates the flow behavior of carboxymethyl cellulose (CMC) solutions carrying glass beads. A CFD-DEM coupling method, validated by experimental measurements, is employed to compare the predictive performance of three widely used drag models-Freestream, Ergun-WenYu, and Di Felice-under varying fluid viscosities and flow velocities, focusing on pressure drop and particle distribution. The results indicate that the Freestream model is better suited to conditions with low shear rates and low particle Reynolds numbers, and offers high computational efficiency. The Ergun-WenYu model performs best in transitional regimes where fluid–particle bidirectional coupling becomes increasingly significant. The Di Felice model demonstrates superior performance under high shear rate and high Reynolds number conditions, accurately capturing complex fluid–particle interactions. On this basis, a Support Vector Machine (SVM)-based drag model selection framework is proposed, using shear rate (), particle Reynolds number (), and consistency index (K) as input features. The machine learning model effectively addresses the uncertainty in drag model applicability and quantifies the probabilistic boundaries between models. The SVM classifier achieved a classification accuracy of 95.8 % under five-fold cross-validation. Application of this framework reduced the trial-and-error cost in model selection by approximately 66 %, providing a practical and data-driven solution for drag model selection in power-law liquid-solid flow simulations.
{"title":"Research on optimization of drag force model selection and CFD-DEM simulation of power-law liquid-solid two-phase flow","authors":"Shuichang Liu , Zelin Zhong , Yong Zhang , Dongtao Wang , Zheng Cao , Kunyu Ye , Yi Chen","doi":"10.1016/j.powtec.2025.122074","DOIUrl":"10.1016/j.powtec.2025.122074","url":null,"abstract":"<div><div>Drag models describe the interactions between particles and fluid, which directly affect the accuracy of liquid–solid two-phase flow simulations. To explore the applicability of different drag models in simulating the transport of particles in power-law fluids, this study investigates the flow behavior of carboxymethyl cellulose (CMC) solutions carrying glass beads. A CFD-DEM coupling method, validated by experimental measurements, is employed to compare the predictive performance of three widely used drag models-Freestream, Ergun-WenYu, and Di Felice-under varying fluid viscosities and flow velocities, focusing on pressure drop and particle distribution. The results indicate that the Freestream model is better suited to conditions with low shear rates and low particle Reynolds numbers, and offers high computational efficiency. The Ergun-WenYu model performs best in transitional regimes where fluid–particle bidirectional coupling becomes increasingly significant. The Di Felice model demonstrates superior performance under high shear rate and high Reynolds number conditions, accurately capturing complex fluid–particle interactions. On this basis, a Support Vector Machine (SVM)-based drag model selection framework is proposed, using shear rate (<span><math><mi>γ</mi></math></span>), particle Reynolds number (<span><math><msub><mi>Re</mi><mi>p</mi></msub></math></span>), and consistency index (<em>K</em>) as input features. The machine learning model effectively addresses the uncertainty in drag model applicability and quantifies the probabilistic boundaries between models. The SVM classifier achieved a classification accuracy of 95.8 % under five-fold cross-validation. Application of this framework reduced the trial-and-error cost in model selection by approximately 66 %, providing a practical and data-driven solution for drag model selection in power-law liquid-solid flow simulations.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"471 ","pages":"Article 122074"},"PeriodicalIF":4.6,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145882457","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 : 2025-12-26DOI: 10.1016/j.powtec.2025.122082
Jiaquan Wang , Xinbiao Wu , Zhenchao Chang , Yi Tang
Industrial solid wastes such as slag, red mud, and fly ash were utilized to prepare a ternary geopolymer grouting material (GGM), which not only reduces carbon emissions but also promotes resource recycling. However, optimizing mix proportions under multi-waste synergistic effects remains a major challenge. In this study, 27 mix designs were developed, yielding 575 valid compressive strength data points. Four machine-learning models—Random Forest, XGBoost, CNN, and BPNN—were trained, and their hyperparameters were optimized using Particle Swarm Optimization (PSO). The PSO-BPNN achieved the best performance (R2 = 0.97503, MAE = 1.41, MSE = 3.07, RMSE = 1.75, MAPE = 5.96 %) as verified by a pre-defined hold-out experimental dataset (108 samples). SHAP-based interpretability analysis revealed that curing age and water-binder ratio predominantly govern compressive strength (53.1 %), followed by activator concentration and modulus (33.3 %), while solid waste composition contributes the remaining 13.6 %. Practical parameter ranges were derived from SHAP dependence plots: curing age = 10.62–56.00 d, w/b = 0.30–0.51, activator concentration = 1.36–1.99 mol·L−1, modulus = 1.02–2.25, red mud = 0.00–20.33 %, fly ash = 34.25–40.00 %, and slag = 60.13–100.00 %. This study proposes a novel and interpretable framework for strength prediction, providing quantitative guidance for multi-waste optimization and practical insights into the development of sustainable grouting materials for subgrade rehabilitation.
{"title":"Explainable machine learning prediction of compressive strength in ternary industrial waste-based geopolymer grouting material","authors":"Jiaquan Wang , Xinbiao Wu , Zhenchao Chang , Yi Tang","doi":"10.1016/j.powtec.2025.122082","DOIUrl":"10.1016/j.powtec.2025.122082","url":null,"abstract":"<div><div>Industrial solid wastes such as slag, red mud, and fly ash were utilized to prepare a ternary geopolymer grouting material (GGM), which not only reduces carbon emissions but also promotes resource recycling. However, optimizing mix proportions under multi-waste synergistic effects remains a major challenge. In this study, 27 mix designs were developed, yielding 575 valid compressive strength data points. Four machine-learning models—Random Forest, XGBoost, CNN, and BPNN—were trained, and their hyperparameters were optimized using Particle Swarm Optimization (PSO). The PSO-BPNN achieved the best performance (R<sup>2</sup> = 0.97503, MAE = 1.41, MSE = 3.07, RMSE = 1.75, MAPE = 5.96 %) as verified by a pre-defined hold-out experimental dataset (108 samples). SHAP-based interpretability analysis revealed that curing age and water-binder ratio predominantly govern compressive strength (53.1 %), followed by activator concentration and modulus (33.3 %), while solid waste composition contributes the remaining 13.6 %. Practical parameter ranges were derived from SHAP dependence plots: curing age = 10.62–56.00 d, w/b = 0.30–0.51, activator concentration = 1.36–1.99 mol·L<sup>−1</sup>, modulus = 1.02–2.25, red mud = 0.00–20.33 %, fly ash = 34.25–40.00 %, and slag = 60.13–100.00 %. This study proposes a novel and interpretable framework for strength prediction, providing quantitative guidance for multi-waste optimization and practical insights into the development of sustainable grouting materials for subgrade rehabilitation.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"471 ","pages":"Article 122082"},"PeriodicalIF":4.6,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145882544","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 : 2025-12-26DOI: 10.1016/j.powtec.2025.122078
Xiaowei Li, Luzheng Chen, Pulin Dai, Yongjun Xian
The efficient flotation separation of chalcopyrite from galena presents a significant challenge in mineral processing, primarily due to their natural floatability and complex surface interactions during grinding and conditioning. These interactions often lead to unintended activation and surface homogenization. To achieve selective separation of chalcopyrite from galena, this study investigates the enhanced depression of galena by carboxymethyl cellulose (CMC) via Cu2+ modification on the galena surface. The micro-flotation of pure minerals showed that after the Cu2+ modification treatment, the galena recovery sharply decreased from 88.97 % to 3.38 % at pH 9.0, whereas the chalcopyrite maintained a high recovery at 78.28 %. To clarify this selective depression, adsorption measurements were conducted on both galena and chalcopyrite to confirm the selective enhancement of CMC adsorption on the galena surface. The surface characterization showed that Cu2+ forms Cu-S bonds on the galena surface. These bonds act as activation sites for CMC and facilitate the formation of a stable S-Cu-O-CMC coordination structure; however, this structure was not observed on the chalcopyrite surface. Subsequently, the electrochemical analysis of chalcopyrite and galena treated with Cu2+ activation and CMC depression demonstrated that a dense and hydrophilic layer formed on the galena surface. This layer increased the galena surface resistance and suppressed electroactivity, while chalcopyrite showed minimal electrochemical response on the surface. Moreover, the molecular dynamics (MD) simulations for galena visually illustrate a denser CMC adsorption configuration on the modified galena surface with Cu2+, compared with that on the chalcopyrite. In summary, these findings highlight the crucial role of Cu2+ in selectively enhancing the CMC adsorption by modifying the galena surface, providing an effective strategy for the ion-modified flotation separation of chalcopyrite from galena.
{"title":"Depression enhancement of carboxymethyl cellulose on galena by copper ions modification in flotation of chalcopyrite","authors":"Xiaowei Li, Luzheng Chen, Pulin Dai, Yongjun Xian","doi":"10.1016/j.powtec.2025.122078","DOIUrl":"10.1016/j.powtec.2025.122078","url":null,"abstract":"<div><div>The efficient flotation separation of chalcopyrite from galena presents a significant challenge in mineral processing, primarily due to their natural floatability and complex surface interactions during grinding and conditioning. These interactions often lead to unintended activation and surface homogenization. To achieve selective separation of chalcopyrite from galena, this study investigates the enhanced depression of galena by carboxymethyl cellulose (CMC) via Cu<sup>2+</sup> modification on the galena surface. The micro-flotation of pure minerals showed that after the Cu<sup>2+</sup> modification treatment, the galena recovery sharply decreased from 88.97 % to 3.38 % at pH 9.0, whereas the chalcopyrite maintained a high recovery at 78.28 %. To clarify this selective depression, adsorption measurements were conducted on both galena and chalcopyrite to confirm the selective enhancement of CMC adsorption on the galena surface. The surface characterization showed that Cu<sup>2+</sup> forms Cu-S bonds on the galena surface. These bonds act as activation sites for CMC and facilitate the formation of a stable S-Cu-O-CMC coordination structure; however, this structure was not observed on the chalcopyrite surface. Subsequently, the electrochemical analysis of chalcopyrite and galena treated with Cu<sup>2+</sup> activation and CMC depression demonstrated that a dense and hydrophilic layer formed on the galena surface. This layer increased the galena surface resistance and suppressed electroactivity, while chalcopyrite showed minimal electrochemical response on the surface. Moreover, the molecular dynamics (MD) simulations for galena visually illustrate a denser CMC adsorption configuration on the modified galena surface with Cu<sup>2+</sup>, compared with that on the chalcopyrite. In summary, these findings highlight the crucial role of Cu<sup>2+</sup> in selectively enhancing the CMC adsorption by modifying the galena surface, providing an effective strategy for the ion-modified flotation separation of chalcopyrite from galena.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"471 ","pages":"Article 122078"},"PeriodicalIF":4.6,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145882531","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}
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