Pub Date : 2025-12-04DOI: 10.1016/j.powtec.2025.122024
Aibing Zhang , Yawei Zhang , Yuxiang Hu , Guowei Dai , Wuwei Mao , Yu Huang , Hu Zheng
Submarine granular avalanches can result in catastrophic consequences, which are related to the unique undersea environment. However, few studies on the flow characteristics of submarine granular avalanches have considered the influence of water pressure environment at different depths. In this paper, the effect of water pressure on the flow characteristics of submarine granular avalanches is investigated using a rotating drum capable of providing various water pressure levels. By extracting the statistical data pertaining to episodic avalanches, it was found that as water pressure increases, the avalanche angle gradually decreases. The escalation of water pressure leads to a reduction in the standard deviation of the slope time series data. This indicates that increasing environmental pressure exerts a weakening effect on avalanche amplitude. Additionally, with increasing water pressure, the erosive effect exerted by the surrounding water on the collapsing granular flow gradually diminishes. This study provides new insights into the flow characteristics of submarine granular avalanches.
{"title":"Influence of environmental pressure on submarine granular avalanches slope characteristics","authors":"Aibing Zhang , Yawei Zhang , Yuxiang Hu , Guowei Dai , Wuwei Mao , Yu Huang , Hu Zheng","doi":"10.1016/j.powtec.2025.122024","DOIUrl":"10.1016/j.powtec.2025.122024","url":null,"abstract":"<div><div>Submarine granular avalanches can result in catastrophic consequences, which are related to the unique undersea environment. However, few studies on the flow characteristics of submarine granular avalanches have considered the influence of water pressure environment at different depths. In this paper, the effect of water pressure on the flow characteristics of submarine granular avalanches is investigated using a rotating drum capable of providing various water pressure levels. By extracting the statistical data pertaining to episodic avalanches, it was found that as water pressure increases, the avalanche angle gradually decreases. The escalation of water pressure leads to a reduction in the standard deviation of the slope time series data. This indicates that increasing environmental pressure exerts a weakening effect on avalanche amplitude. Additionally, with increasing water pressure, the erosive effect exerted by the surrounding water on the collapsing granular flow gradually diminishes. This study provides new insights into the flow characteristics of submarine granular avalanches.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"470 ","pages":"Article 122024"},"PeriodicalIF":4.6,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733841","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 : 2025-12-04DOI: 10.1016/j.powtec.2025.122006
Keita Kondo, Yukiya Endo, Toshiyuki Niwa
This study investigated a solventless amorphization and pelletization technique using a mechanical powder processer, which can produce amorphous drug-layered pellets by mechanical processing of drug crystals and inactive spheres without using solvents or heating. The aim of this study was to shorten the processing time required for full amorphization of the drug as well as to achieve high loading of the amorphized drug onto the pellets. Indomethacin crystals and corn starch particles were mechanically treated at various processing times, rotor speeds, sample volumes, and weight ratios, and the pellets obtained were characterized using solid-state and particle analytical techniques. At 10 % drug loading to the carrier, the processing time required to amorphize the drug fully was 10 min, which is significantly shorter than using conventional granulators. The amorphization efficiency was determined by the specific power input to the samples, controllable by the rotor speed. Also, the volume reduction due to rotor revolution affected the amorphization of the drug. In the mechanical processing of indomethacin and starch at various weight ratios using the optimized conditions, fully amorphized drug-layered pellets with a drug content of around 15 % could be obtained, which exhibited supersaturation dissolution characteristics.
{"title":"Solventless amorphization and pelletization using a mechanical powder processor; investigation of effective approaches for preparing amorphous drug-layered pellets","authors":"Keita Kondo, Yukiya Endo, Toshiyuki Niwa","doi":"10.1016/j.powtec.2025.122006","DOIUrl":"10.1016/j.powtec.2025.122006","url":null,"abstract":"<div><div>This study investigated a solventless amorphization and pelletization technique using a mechanical powder processer, which can produce amorphous drug-layered pellets by mechanical processing of drug crystals and inactive spheres without using solvents or heating. The aim of this study was to shorten the processing time required for full amorphization of the drug as well as to achieve high loading of the amorphized drug onto the pellets. Indomethacin crystals and corn starch particles were mechanically treated at various processing times, rotor speeds, sample volumes, and weight ratios, and the pellets obtained were characterized using solid-state and particle analytical techniques. At 10 % drug loading to the carrier, the processing time required to amorphize the drug fully was 10 min, which is significantly shorter than using conventional granulators. The amorphization efficiency was determined by the specific power input to the samples, controllable by the rotor speed. Also, the volume reduction due to rotor revolution affected the amorphization of the drug. In the mechanical processing of indomethacin and starch at various weight ratios using the optimized conditions, fully amorphized drug-layered pellets with a drug content of around 15 % could be obtained, which exhibited supersaturation dissolution characteristics.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"470 ","pages":"Article 122006"},"PeriodicalIF":4.6,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682388","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 : 2025-12-04DOI: 10.1016/j.powtec.2025.122023
M. Dikty
A pneumatic conveying can take place in different flow modes also depending on the bulk solid (granulate or fine particles). The optimization of pneumatic conveying systems in terms of energy saving, grain destruction and pipe wear is usually carried out for granules by operating the pneumatic conveying system at the pressure drop minimum. With fine particles, however, the pressure drop minimum is not as pronounced as with granules. Furthermore, it makes sense from an energy point of view to operate the pneumatic conveying system of fine particles to the left side of the pressure drop minimum in the state diagram. However, this is associated with pressure fluctuations. In this paper, the pressure pulsation is systematically investigated in dependence of the Geldart Group C and A. Five different bulk solids were used, two of Geldart Group A and three of Group C. The pressure signal of the pneumatic conveying line was used to identify the point of beginning pipe blockages. The evaluation of pressure fluctuations is systematically linked to the solid loading ratio (SLR), the Froude number, and the Euler number through dimensional analysis. Both qualitative and quantitative assessments of the resulting relationships are conducted.
The pulse amplitude rises sharply near the blockage velocity; an increase >45° in the pulse-amplitude–Froude diagram marks the limit below which the gas velocity should not be further reduced. The ratio of maximum amplitudes is at least 4.3 and can increase up to 11.2. The slope of pulse growth also indicates the energetic optimum, identified by a slope > 45°.
{"title":"Energetics optimization of pneumatic conveying systems due to pressure signal analysis for Geldard Group C and A bulk solids","authors":"M. Dikty","doi":"10.1016/j.powtec.2025.122023","DOIUrl":"10.1016/j.powtec.2025.122023","url":null,"abstract":"<div><div>A pneumatic conveying can take place in different flow modes also depending on the bulk solid (granulate or fine particles). The optimization of pneumatic conveying systems in terms of energy saving, grain destruction and pipe wear is usually carried out for granules by operating the pneumatic conveying system at the pressure drop minimum. With fine particles, however, the pressure drop minimum is not as pronounced as with granules. Furthermore, it makes sense from an energy point of view to operate the pneumatic conveying system of fine particles to the left side of the pressure drop minimum in the state diagram. However, this is associated with pressure fluctuations. In this paper, the pressure pulsation is systematically investigated in dependence of the Geldart Group C and A. Five different bulk solids were used, two of Geldart Group A and three of Group C. The pressure signal of the pneumatic conveying line was used to identify the point of beginning pipe blockages. The evaluation of pressure fluctuations is systematically linked to the solid loading ratio (SLR), the Froude number, and the Euler number through dimensional analysis. Both qualitative and quantitative assessments of the resulting relationships are conducted.</div><div>The pulse amplitude rises sharply near the blockage velocity; an increase >45° in the pulse-amplitude–Froude diagram marks the limit below which the gas velocity should not be further reduced. The ratio of maximum amplitudes is at least 4.3 and can increase up to 11.2. The slope of pulse growth also indicates the energetic optimum, identified by a slope > 45°.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"470 ","pages":"Article 122023"},"PeriodicalIF":4.6,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682390","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 : 2025-12-04DOI: 10.1016/j.powtec.2025.122018
Hang Lu , Fei Huang , Wenting Zhao , Zhuoying Shan , Qingdong He , Jingyu Zhang , Wenbo Wang
A sustainable strategy was developed to convert graphite tailings (GT), a solid waste, into a hierarchical porous silicate adsorbent with engineered multiple active sites (denoted as GTPM12h) through an integrated mechanochemical-hydrothermal route for efficient decontamination of organic dye wastewater. The reconstructed silicate phases are enriched with oxygen-containing functional groups and metal active sites, resulting in remarkably enhanced adsorption performance. GTPM12h exhibits superior adsorption capacities of 379.76 mg·g−1 for methylene blue and 487.57 mg·g−1 for methyl violet over a broad pH range (5–9), outperforming most commercial activated carbons. At a low dosage (0.6 g·L−1), the removal efficiency of dyes exceeds 99.9 % in both single and ternary mixed dye systems and remains at 92.4 % after five cycles. The adsorption process follows a chemisorption-dominated monolayer mechanism driven by synergistic electrostatic attraction, hydrogen bonding, and ion exchange. This study presents an eco-friendly strategy addressing dual environmental challenges: upcycling industrial waste and remediating water pollution.
{"title":"Multi-active-site-engineered hierarchical porous silicate synthesized from graphite tailings for exceptional pollutant removal","authors":"Hang Lu , Fei Huang , Wenting Zhao , Zhuoying Shan , Qingdong He , Jingyu Zhang , Wenbo Wang","doi":"10.1016/j.powtec.2025.122018","DOIUrl":"10.1016/j.powtec.2025.122018","url":null,"abstract":"<div><div>A sustainable strategy was developed to convert graphite tailings (GT), a solid waste, into a hierarchical porous silicate adsorbent with engineered multiple active sites (denoted as GTPM12h) through an integrated mechanochemical-hydrothermal route for efficient decontamination of organic dye wastewater. The reconstructed silicate phases are enriched with oxygen-containing functional groups and metal active sites, resulting in remarkably enhanced adsorption performance. GTPM12h exhibits superior adsorption capacities of 379.76 mg·g<sup>−1</sup> for methylene blue and 487.57 mg·g<sup>−1</sup> for methyl violet over a broad pH range (5–9), outperforming most commercial activated carbons. At a low dosage (0.6 g·L<sup>−1</sup>), the removal efficiency of dyes exceeds 99.9 % in both single and ternary mixed dye systems and remains at 92.4 % after five cycles. The adsorption process follows a chemisorption-dominated monolayer mechanism driven by synergistic electrostatic attraction, hydrogen bonding, and ion exchange. This study presents an eco-friendly strategy addressing dual environmental challenges: upcycling industrial waste and remediating water pollution.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"470 ","pages":"Article 122018"},"PeriodicalIF":4.6,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682396","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 : 2025-12-04DOI: 10.1016/j.powtec.2025.122013
Wenshuai Wang , Peng Zhang , Xinjian Sun , Zhen Gao
Environmentally friendly geopolymer concrete holds considerable promise for the construction industry as a potential substitute for Portland cement concrete. To promote application of geopolymer concrete in hydraulic and civil engineering structures, it is necessary to improve abrasion resistance of geopolymer concrete. In this study, underwater abrasion and ring abrasion tests were carried out to assess the effect and mechanism of nano-SiO2 on abrasion resistance of nano-SiO2-reinforced geopolymer concrete containing hybrid fiber (NS-GCF). Three-dimensional laser scanning technology was used to investigate the relationship between the abrasion damage distribution of NS-GCF and nano-SiO2 contents. Microscopic tests were conducted to reveal the mechanisms behind the enhanced abrasion resistance of NS-GCF. Based on the thermodynamic fractal model, the correlations between the microscopic pore characteristics and the macroscopic abrasion resistance of NS-GCF were established. The research results indicated that the abrasion resistance of NS-GCF with the addition of 1.5 % nano-SiO2 is optimal, showing a maximum improvement of up to 99.3 %. Nano-SiO2 can improve the uniformity of abrasion damage distribution on the surface of NS-GCF. NS-GCF was more suitable for application in hydraulic and civil engineering structures where bedload media predominated. The mechanism for the enhanced abrasion resistance was attributed to nano-SiO2 increasing the gel content within the matrix, improving the pore structure, and enhancing the bond between fibers and concrete matrix. The transition pores and large pores within the matrix exhibited distinct fractal characteristics, and the surface fractal dimensions of the pores were closely linearly correlated with abrasion resistance, with a correlation coefficient exceeding 0.9.
{"title":"Assessing the influence of nano-SiO2 on abrasion resistance of geopolymer concrete reinforced with hybrid fiber through abrasion tests","authors":"Wenshuai Wang , Peng Zhang , Xinjian Sun , Zhen Gao","doi":"10.1016/j.powtec.2025.122013","DOIUrl":"10.1016/j.powtec.2025.122013","url":null,"abstract":"<div><div>Environmentally friendly geopolymer concrete holds considerable promise for the construction industry as a potential substitute for Portland cement concrete. To promote application of geopolymer concrete in hydraulic and civil engineering structures, it is necessary to improve abrasion resistance of geopolymer concrete. In this study, underwater abrasion and ring abrasion tests were carried out to assess the effect and mechanism of nano-SiO<sub>2</sub> on abrasion resistance of nano-SiO<sub>2</sub>-reinforced geopolymer concrete containing hybrid fiber (NS-GCF). Three-dimensional laser scanning technology was used to investigate the relationship between the abrasion damage distribution of NS-GCF and nano-SiO<sub>2</sub> contents. Microscopic tests were conducted to reveal the mechanisms behind the enhanced abrasion resistance of NS-GCF. Based on the thermodynamic fractal model, the correlations between the microscopic pore characteristics and the macroscopic abrasion resistance of NS-GCF were established. The research results indicated that the abrasion resistance of NS-GCF with the addition of 1.5 % nano-SiO<sub>2</sub> is optimal, showing a maximum improvement of up to 99.3 %. Nano-SiO<sub>2</sub> can improve the uniformity of abrasion damage distribution on the surface of NS-GCF. NS-GCF was more suitable for application in hydraulic and civil engineering structures where bedload media predominated. The mechanism for the enhanced abrasion resistance was attributed to nano-SiO<sub>2</sub> increasing the gel content within the matrix, improving the pore structure, and enhancing the bond between fibers and concrete matrix. The transition pores and large pores within the matrix exhibited distinct fractal characteristics, and the surface fractal dimensions of the pores were closely linearly correlated with abrasion resistance, with a correlation coefficient exceeding 0.9.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"470 ","pages":"Article 122013"},"PeriodicalIF":4.6,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733782","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 : 2025-12-04DOI: 10.1016/j.powtec.2025.121994
Yuting Shang , Mingan Zou , Zhihong Zhao , Zhiyan Lai , Tao Liu
This study established a top-down methodology for nano-amorphous rutin production, with systematic evaluation of amorphous state effects (polymer-based vs. small molecule-based) on both manufacturing processes and microneedle formulations. Experimental data coupled with molecular dynamics simulations confirmed that strategic selection of small-molecule co-formers with optimized ratios could generate smaller nanoparticles (288 nm) exhibiting superior physical stability compared to polymer-based nano-amorphous systems. Radial distribution function analysis of the amino acid-rutin system detected robust intermolecular interactions (708.8103 kcal/mol), where the formed hydrogen-bonding network effectively suppressed rutin recrystallization. The dual strategy combining nanotechnology with amorphization technology achieved remarkable dissolution enhancement (85 % drug release), substantially exceeding the performance of microparticulate systems. This effect was further amplified through lyophilization using a ternary excipient system (hyaluronic acid-povidone-polyvinyl alcohol), which improved mechanical resilience. The nano-co-amorphous powder demonstrated 69.87 μg/mL transdermal flux, representing significant advancement over nanocrystalline formulations (49.86 μg/mL). The developed rutin-lysine nano-co-amorphous microneedles exhibited clinically relevant wound healing efficacy, validating their therapeutic potential.
{"title":"Optimizing preparation and solidification of drug crystal, amorphous and co-amorphous nanoparticles for microneedles","authors":"Yuting Shang , Mingan Zou , Zhihong Zhao , Zhiyan Lai , Tao Liu","doi":"10.1016/j.powtec.2025.121994","DOIUrl":"10.1016/j.powtec.2025.121994","url":null,"abstract":"<div><div>This study established a top-down methodology for nano-amorphous rutin production, with systematic evaluation of amorphous state effects (polymer-based vs. small molecule-based) on both manufacturing processes and microneedle formulations. Experimental data coupled with molecular dynamics simulations confirmed that strategic selection of small-molecule co-formers with optimized ratios could generate smaller nanoparticles (288 nm) exhibiting superior physical stability compared to polymer-based nano-amorphous systems. Radial distribution function analysis of the amino acid-rutin system detected robust intermolecular interactions (708.8103 kcal/mol), where the formed hydrogen-bonding network effectively suppressed rutin recrystallization. The dual strategy combining nanotechnology with amorphization technology achieved remarkable dissolution enhancement (85 % drug release), substantially exceeding the performance of microparticulate systems. This effect was further amplified through lyophilization using a ternary excipient system (hyaluronic acid-povidone-polyvinyl alcohol), which improved mechanical resilience. The nano-co-amorphous powder demonstrated 69.87 μg/mL transdermal flux, representing significant advancement over nanocrystalline formulations (49.86 μg/mL). The developed rutin-lysine nano-co-amorphous microneedles exhibited clinically relevant wound healing efficacy, validating their therapeutic potential.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"470 ","pages":"Article 121994"},"PeriodicalIF":4.6,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733843","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 : 2025-12-03DOI: 10.1016/j.powtec.2025.122003
Haotian Zhang, Jianwu Zeng, Luzheng Chen
Magnetic aggregation readily occurs during the low-intensity magnetic separation (WLIMS) of fine-grained magnetite, and the magnetic agglomeration plays a crucial role on the WLIMS performance. However, current investigation for the mechanism of magnetic agglomeration is primarily derived from idealized models, thus offering limited guidance for practical applications. In this investigation, the effects of various operating conditions on magnetic agglomeration behavior and the dynamic characteristics of magnetic agglomeration were systematically investigated based on the CFD-DEM-FEM method, in both idealized models and practical separation models, respectively. The results indicate that when the interparticle distance is less than three times the particle diameter, the magnetic dipole - dipole force acts as the primary driving force for magnetic agglomeration. And, the stability of the magnetic chains formed by particles increases with decreasing particle size, increasing background magnetic field strength, and a lower proportion of intergrown particles. Further analysis shows that by adjusting the magnetic system orientation, making the slurry feed perpendicular to the magnetic field, the mechanical entrainment from agglomeration could be effectively reduced. Furthermore, during the semi-counter-current WLIMS process, a significant number of intergrowth particles remain mechanically entrained within magnetic aggregates in the rinsing zone, which severely reduces the concentrate grade. This study reveals the fundamental mechanisms governing magnetic agglomeration in the WLIMS process and establishes a theoretical foundation for the structural optimization of WLIMS separator.
{"title":"Numerical simulation study on magnetic agglomeration behavior in wet low-intensity magnetic separation","authors":"Haotian Zhang, Jianwu Zeng, Luzheng Chen","doi":"10.1016/j.powtec.2025.122003","DOIUrl":"10.1016/j.powtec.2025.122003","url":null,"abstract":"<div><div>Magnetic aggregation readily occurs during the low-intensity magnetic separation (WLIMS) of fine-grained magnetite, and the magnetic agglomeration plays a crucial role on the WLIMS performance. However, current investigation for the mechanism of magnetic agglomeration is primarily derived from idealized models, thus offering limited guidance for practical applications. In this investigation, the effects of various operating conditions on magnetic agglomeration behavior and the dynamic characteristics of magnetic agglomeration were systematically investigated based on the CFD-DEM-FEM method, in both idealized models and practical separation models, respectively. The results indicate that when the interparticle distance is less than three times the particle diameter, the magnetic dipole - dipole force acts as the primary driving force for magnetic agglomeration. And, the stability of the magnetic chains formed by particles increases with decreasing particle size, increasing background magnetic field strength, and a lower proportion of intergrown particles. Further analysis shows that by adjusting the magnetic system orientation, making the slurry feed perpendicular to the magnetic field, the mechanical entrainment from agglomeration could be effectively reduced. Furthermore, during the semi-counter-current WLIMS process, a significant number of intergrowth particles remain mechanically entrained within magnetic aggregates in the rinsing zone, which severely reduces the concentrate grade. This study reveals the fundamental mechanisms governing magnetic agglomeration in the WLIMS process and establishes a theoretical foundation for the structural optimization of WLIMS separator.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"470 ","pages":"Article 122003"},"PeriodicalIF":4.6,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682337","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 : 2025-12-03DOI: 10.1016/j.powtec.2025.122002
Bowen Jiang , Chi Li , Shuanhu Li , De Yao
The large-scale accumulation of coal gangue has led to severe ecological risks and resource waste, while underground backfilling provides a promising pathway for its in-situ utilization. However, the coupled mechanisms of slurry flow, microstructural evolution, and reinforcement effectiveness during gangue-based grouting remain insufficiently understood. This study aims to systematically investigate the flow characteristics, filling effectiveness, and structural response of high-concentration coal gangue slurry in pipeline transport and grouting processes, in order to provide theoretical and technical support for its efficient and sustainable resource utilization. A multi-scale coupled simulation framework integrating the Euler–VOF model and the discrete element method (PFC) was established. Particle size distribution was optimized based on the Fuller–Thompson theory, and slurries with solid volume fractions of 60 %–80 % were modeled. The effects of particle size and concentration on flow trajectories, disturbance intensity, porosity evolution, and displacement fields were analyzed. The results indicate that increasing concentration leads to more concentrated particle trajectories, reduced radial and Z-directional disturbances, and enhanced flow stability. Smaller particles (0.3 mm) exhibit better streamline adherence and shorter residence times, whereas larger particles (0.5 mm) deviate more due to inertial effects. PFC simulations show that grouting induces plume-like diffusion, increases porosity, restructures particle skeletons, and reconstructs force chains, thereby improving load-bearing capacity and stability. The optimized borehole layout effectively suppresses displacement in the overlying strata and reduces high-displacement zones. Engineering application in the Longwanggou Coal Mine demonstrates that five boreholes can accommodate 1.323 Mt. of coal gangue and reduce CO₂ emissions by approximately 0.992 Mt. This work confirms that optimizing particle grading, slurry concentration, and borehole arrangement enables large-scale, in-situ, and high-efficiency disposal of coal gangue. The findings provide a feasible and scalable technical pathway for safe and sustainable backfilling, with substantial ecological and carbon mitigation benefits.
{"title":"Evaluation on flow characteristics and filling efficiency of coal gangue slurry in Longwanggou Coal Mine, China","authors":"Bowen Jiang , Chi Li , Shuanhu Li , De Yao","doi":"10.1016/j.powtec.2025.122002","DOIUrl":"10.1016/j.powtec.2025.122002","url":null,"abstract":"<div><div>The large-scale accumulation of coal gangue has led to severe ecological risks and resource waste, while underground backfilling provides a promising pathway for its in-situ utilization. However, the coupled mechanisms of slurry flow, microstructural evolution, and reinforcement effectiveness during gangue-based grouting remain insufficiently understood. This study aims to systematically investigate the flow characteristics, filling effectiveness, and structural response of high-concentration coal gangue slurry in pipeline transport and grouting processes, in order to provide theoretical and technical support for its efficient and sustainable resource utilization. A multi-scale coupled simulation framework integrating the Euler–VOF model and the discrete element method (PFC) was established. Particle size distribution was optimized based on the Fuller–Thompson theory, and slurries with solid volume fractions of 60 %–80 % were modeled. The effects of particle size and concentration on flow trajectories, disturbance intensity, porosity evolution, and displacement fields were analyzed. The results indicate that increasing concentration leads to more concentrated particle trajectories, reduced radial and <em>Z</em>-directional disturbances, and enhanced flow stability. Smaller particles (0.3 mm) exhibit better streamline adherence and shorter residence times, whereas larger particles (0.5 mm) deviate more due to inertial effects. PFC simulations show that grouting induces plume-like diffusion, increases porosity, restructures particle skeletons, and reconstructs force chains, thereby improving load-bearing capacity and stability. The optimized borehole layout effectively suppresses displacement in the overlying strata and reduces high-displacement zones. Engineering application in the Longwanggou Coal Mine demonstrates that five boreholes can accommodate 1.323 Mt. of coal gangue and reduce CO₂ emissions by approximately 0.992 Mt. This work confirms that optimizing particle grading, slurry concentration, and borehole arrangement enables large-scale, in-situ, and high-efficiency disposal of coal gangue. The findings provide a feasible and scalable technical pathway for safe and sustainable backfilling, with substantial ecological and carbon mitigation benefits.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"470 ","pages":"Article 122002"},"PeriodicalIF":4.6,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682399","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 : 2025-12-03DOI: 10.1016/j.powtec.2025.122019
Alexandra Hübl, Felix E.B. Brettner, Florentin Baur, Viktoria Planz, Maike Windbergs
Effective drug delivery to the lung often implies selective spatial deposition of the active molecule in a specific lung region, such as the bronchi for asthma therapy or the alveoli for combating infections of the deep lung. Depending on the site of action, platform formulations adaptable to spatio-selective delivery are valuable. A Design of Experiments approach was employed to systematically analyze the influence of selected spray drying parameters on mannitol particle characteristics. Additionally, one candidate was formulated with varying concentrations of leucine as an aerosolization enhancer. Based on their physicochemical characteristics, three different lead formulations – tailored for tracheobronchial, bronchial, and alveolar deposition – were identified for further nanoparticle encapsulation to develop a pulmonary delivery platform based on spray-dried amphiphilic cyclodextrin nano-in-microparticles. The formulations exhibited mean geometric particle diameters of 1.31 to 1.71 μm and favorable aerosolization performance, with mass median aerodynamic diameters of 4.69 ± 0.22, 3.79 ± 0.17 and 2.18 ± 0.55 μm, respectively. Physicochemical characterization of the incorporated nanoparticles revealed hydrodynamic diameters below 200 nm, narrow size distributions, and stable negative surface charges. Moreover, biocompatibility and time-dependent intracellular uptake of the formulations were verified using human in vitro models of bronchi and deep lung. The novel formulations can serve as an adaptive platform enabling targeted delivery of challenging drug candidates and advanced pulmonary therapeutics.
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Pub Date : 2025-12-03DOI: 10.1016/j.powtec.2025.122017
Yaolu Chen , Hailong Wang , Haolong Guo , Yanhong Han
The effective utilization of solid waste has become a key factor in the development of sustainable green cementitious material systems. Red mud (RM) is a smelting waste with potential cementitious activity. The existing treatment methods are limited to structural fragmentation and surface area enhancement. In response to this issue, this study proposes a mixed mechanical activation method utilizing RM and granulated blast furnace slag (GBFS) as composite precursors. By characterizing the structural disturbance characteristics through particle size analysis and X-ray diffraction (XRD), and combining alkali leaching experiments with the shrinkage core model (SCM), the dissolution kinetics behavior and the evolution of its controlling mechanisms are elucidated. The mixed mechanical activation (M-R) and homogeneous mixing (H-R) methods were compared, and the formation of C-(A)-S-H gel, the evolution of Fe-O-Si bonds, the content of structurally bound water, and the release of calcium sources in the hydration products were analyzed. The results showed that M-R induced interface pre-polymerization and formed new diffraction peaks of Si-O-Al/Fe; promoted the excitation of reaction sites and the dissolution of Si/Al in the system, resulting in a 52.10 % increase in Al dissolution efficiency compared to the H-R system; The hydration kinetics shifts from surface reaction control to shell diffusion control; when RM: GBFS = 5:5, the hydration product is denser and the compressive strength reaches a maximum of 55.19 MPa; compared to the H-M group, the M-R group showed the highest increase in bound water content by 34.55 %. This study offers a theoretical foundation for RM application in green cementitious materials.
固体废物的有效利用已成为发展可持续绿色胶凝材料系统的关键因素。赤泥是一种具有潜在胶凝活性的冶炼废渣。现有的处理方法仅限于结构破碎和表面积增强。针对这一问题，本研究提出了一种以RM和粒状高炉渣（GBFS）为复合前驱体的混合机械活化方法。通过粒度分析和x射线衍射（XRD）表征结构扰动特征，结合碱浸实验和收缩核模型（SCM），阐明了溶出动力学行为及其控制机理的演变。比较了混合机械活化法（M-R）和均相混合法（H-R），分析了C-(A)- s - h凝胶的形成、Fe-O-Si键的演化、结构结合水的含量以及水化产物中钙源的释放。结果表明：M-R诱导界面预聚合，形成新的Si-O-Al/Fe衍射峰；促进了反应位点的激发和体系中Si/Al的溶解，使得Al的溶解效率比H-R体系提高了52.10%；水化动力学由表面反应控制转向壳层扩散控制；RM: GBFS = 5:5时，水化产物密度较大，抗压强度最大值为55.19 MPa；与H-M组相比，M-R组的束缚水含量最高，提高了34.55%。本研究为RM在绿色胶凝材料中的应用提供了理论基础。
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