Powder Technology最新文献

{"title":"Impact of inlet flow rate on dynamic liquid film thickness and flow stability in spiral concentrator","authors":"Huizhong Liu ,&nbsp;Jian Wang","doi":"10.1016/j.powtec.2025.121472","DOIUrl":"10.1016/j.powtec.2025.121472","url":null,"abstract":"<div><div>The dynamic behavior of liquid films, particularly thickness variations, critically governs separation efficiency in spiral concentrators. During operation, flow instabilities in specific concentrator designs trigger periodic rolling waves that significantly alter hydrodynamic characteristics and particle transport. Notably, this phenomenon remains underexplored in mineral processing research. Through integrated experimental and computational fluid dynamics (CFD) simulations, we systematically investigated rolling wave dynamics in industrial-scale spiral concentrators. Our findings demonstrate that wave morphology correlates with trough geometry, surface flow regimes, and particle transport characteristics at the base. Inlet flow rate (Q) emerged as a pivotal control parameter: at Q = 9 L/min, waves exhibited maximum amplitude but minimal frequency and stability; Q = 11 L/min yielded optimal waveform stability; while Q = 13 L/min generated peak Froude numbers (<em>Fr</em> ≈ 2.83), following a unimodal trend mirroring wave height evolution. Crucially, periodic waves modulate near-wall shear rates, inducing Bagnold force fluctuations that govern particle loosening. Elevated velocity gradients at Q = 9/13 L/min promoted significant particle agitation and segregation through ±38 % Bagnold force variations, whereas stabilized shear rates at Q = 11 L/min enabled uniform particle flow. This study offers significant insights into the distribution and motion characteristics of particles under rolling wave conditions.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"466 ","pages":"Article 121472"},"PeriodicalIF":4.6,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144721382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical investigation on agglomeration of reduced iron ore powders in a fluidized bed and the inhibiting effects of non-adhesive additives","authors":"Ruo Nan Dang,&nbsp;Xiang Jun Liu","doi":"10.1016/j.powtec.2025.121482","DOIUrl":"10.1016/j.powtec.2025.121482","url":null,"abstract":"<div><div>Fluidized direct reduction of iron ore particles is a potential technology for clean production of ironmaking. Agglomeration and de-fluidization of particles is a key problem for its application. In this study, a comprehensive CFD-DEM mathematical model for two-phase flow of reduced iron ore particles and high temperature gases in a fluidized bed is established, including a time and temperature dependent expression of solid bridge forces among reduced iron ore particles. A comparative study of solid bridging forces on flow and aggregation is conducted, revealing the detailed agglomeration behaviors. Effects of non-adhesive additives on inhibiting agglomeration are investigated. The addition of non-adhesive particles effectively reduces the proportion and size of agglomerates in beds, and a 15 % addition amount is suggested in this study. By adding non-adhesive particles, the working velocity interval can be extended towards lower gas velocities, and the working temperature interval towards higher temperatures.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"466 ","pages":"Article 121482"},"PeriodicalIF":4.6,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144724107","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":"Simulation method of the functional density cellular automaton for non-uniform flow in bubbling fluidized beds","authors":"He Kun ,&nbsp;Zheng Zhong","doi":"10.1016/j.powtec.2025.121479","DOIUrl":"10.1016/j.powtec.2025.121479","url":null,"abstract":"<div><div>This paper presents a functional density cellular automaton model that conveniently expresses the clustering effect between gas and solid phases. The study simulates the settlement process of single particles and validates the correctness and effectiveness of the functional density approach for gas-solid interactions by comparing with findings in existing literature. The model also investigates the fluidization states of solid particles under varying gas and solid densities. Results indicate that solid particles experience fluctuating resultant forces due to the combined effects of gravity and drag. The magnitude of resultant force increases with solid density, while initially decreasing and then increasing with gas density. When solid particles rise within the fluidized system, their force fluctuations diminish overall. The new model offers unique advantages in characterizing the microscopic behavior of gas-solid interactions in fluidized systems, providing new insights into fluidization mechanisms.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"466 ","pages":"Article 121479"},"PeriodicalIF":4.6,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144739347","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":"A novel ballast roughness index for characterizing the surface undulation anisotropy and its application in directional friction of replicated ballast surfaces","authors":"Lihua Xue ,&nbsp;Junhua Xiao ,&nbsp;Jiapei Ma ,&nbsp;Kaichao Wang ,&nbsp;Yunbo Huo","doi":"10.1016/j.powtec.2025.121457","DOIUrl":"10.1016/j.powtec.2025.121457","url":null,"abstract":"<div><div>The friction coefficient of ballast particles is a critical parameter influencing the dynamic stability of ballasted beds. Currently, friction tests are commonly used to study ballast friction behavior. However, the anisotropy of surface roughness causes significant directional variations in friction coefficients. Conventional roughness indices fail to adequately capture these features, hindering quantitative correlations between friction coefficients and surface morphology. To address this issue, this study analyzed the statistical characteristics of surface roughness anisotropy from 584 real ballast particles. Based on the findings, a comprehensive roughness index was proposed, incorporating surface undulation amplitude, inclination and its anisotropy. The validity of the proposed index was confirmed through a comparison with conventional roughness indices. Then, the new roughness index was applied to ballast friction tests conducted along orthogonal directions. A linear correlation was identified between the index and the friction coefficients in the corresponding directions. In addition, the directional difference in friction was found to decrease with increasing normal load, indicating a reduced influence of roughness under higher stress conditions.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"466 ","pages":"Article 121457"},"PeriodicalIF":4.6,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144758068","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":"Development of a high shear wet granulation regime map for the controlled agglomeration of heat sensitive amorphous food powders","authors":"Yashodh H. Karunanayake ,&nbsp;Linda Brütsch ,&nbsp;Vincent Meunier ,&nbsp;Gerhard Niederreiter ,&nbsp;Agba D. Salman","doi":"10.1016/j.powtec.2025.121470","DOIUrl":"10.1016/j.powtec.2025.121470","url":null,"abstract":"<div><div>If not controlled, temperature and humidity may induce caking of amorphous food powders that can be a major issue during food granulation. Caking must be avoided because it results in the permanent loss of material and process failure. The impact of key process parameters to achieve controlled particle agglomeration by avoiding caking in a High Shear Granulator was assessed across a range of Maltodextrins. Findings reveal that increasing impeller speed, batch size and run time promoted the rate of heat generation in the system. The resulting increase in bed temperature was found to impact the different Maltodextrin powders to varying extents depending on the powder T_g, with high DE Maltodextrins showing greater sensitivity to temperature increases. This study also highlighted that high DE Maltodextrins require less water for effective granulation. This behavior correlated with the rate at which the water binder's viscosity increases as it incorporates Maltodextrin during granulation. High DE Maltodextrins demonstrated slower viscosity rises with increased solid composition than low DE counterparts, producing binder systems that remains mobile and adhesive at higher solid contents, thereby facilitating more efficient granulation. A parameter <span><math><msub><mi>k</mi><mi>μ</mi></msub></math></span> was modelled to reflect this relationship. The parameters (T- T_g) and <span><math><mfenced><mrow><mi>L</mi><mo>/</mo><mi>S</mi></mrow></mfenced><mo>/</mo><msub><mi>k</mi><mi>μ</mi></msub></math></span> were then used to produce a caking regime map for the High Shear Granulation system. This regime map delineates an optimal region for controlled agglomeration and a region where a high likelihood of caking occurs. The threshold of this caking region was set at a T-Tg of 40 °C and <span><math><mfenced><mrow><mi>L</mi><mo>/</mo><mi>S</mi></mrow></mfenced><mo>/</mo><msub><mi>k</mi><mi>μ</mi></msub></math></span> value of 0.0325.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"466 ","pages":"Article 121470"},"PeriodicalIF":4.6,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144739351","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":"Pressure-driven dynamic sintering mechanism and fracture failure mode in bimetallic surface coating composite interfacial nanoparticle","authors":"Weishan Lv ,&nbsp;Jianwei Lv ,&nbsp;Suhang Wei ,&nbsp;Jiaxin Liu ,&nbsp;Cai Chen ,&nbsp;Yong Kang","doi":"10.1016/j.powtec.2025.121476","DOIUrl":"10.1016/j.powtec.2025.121476","url":null,"abstract":"<div><div>Understanding the underlying sintering diffusion mechanism and mechanical failure modes of bimetallic surface coating nanoparticles under pressure-driven sintering can promote the synthesis and application of die-attach materials. In this paper, we innovatively proposed a continuous molecular dynamics (MD) method to reveal the fusion mechanism and surface mechanical response of Cu@Ag bimetallic surface coating composite nanoparticles under pressure-assisted sintering. The results indicate that the thickness of the coating and the sintering temperature have a synergistic regulatory effect on the sintering kinetics and structural evolution. There is a critical threshold for the thickness of the coating, which can significantly regulate the topological evolution of diffusion paths through the formation of stacking faults and dislocations. The sintering temperature affects the competitive mechanism between dislocation proliferation and slip by adjusting the diffusion activation energy. The triple coupling mechanism of “diffusion-interface-deformation” in bimetallic composite materials was first elucidated through uniaxial tensile simulation. Changing the thickness of coating can regulate the diffusion path and interface stress state, combined with the activation effect of sintering temperature on the deformation mechanism, jointly inducing the evolution of the material from brittle fracture to ductile fracture and then to adhesive fracture. This study provides new theoretical basis for design of coating nanoparticle materials, especially the discovery of critical thickness effects and coupling mechanisms, advancing high performance die-attach materials.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"466 ","pages":"Article 121476"},"PeriodicalIF":4.6,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144724106","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":"Eco-friendly composite dust suppressant based on Enteromorpha cellulose: Preparation, characterization and dust suppression mechanism","authors":"Jinfeng Wang ,&nbsp;Qimeng Zhao ,&nbsp;Zhixin Wei ,&nbsp;Xu Chen ,&nbsp;Jia Ding ,&nbsp;Wenbin Zhao","doi":"10.1016/j.powtec.2025.121477","DOIUrl":"10.1016/j.powtec.2025.121477","url":null,"abstract":"<div><div>In addressing the issue of excessive dust generation during coal mining and transportation, as well as the detrimental impact of Enteromorpha (EP) outbreaks on marine ecosystems, an eco-friendly composite dust suppressant (CPPS) has been developed. This suppressant is created through the carboxymethylation modification of EP cellulose, which serves as the matrix, and incorporates polyvinyl alcohol (PVA) and polyacrylamide (PAM) as monomers. Using consolidation strength as the performance metric, the optimal compounding conditions for the dust suppressant at 60 °C were established through orthogonal experiments. The ideal ratio of the components PVA, PAM, and SDBS was determined to be 10:1:4, resulting in a consolidation strength of 77.3 HA for the optimal formulation. Under a simulated wind speed of 12 m/s, the dust suppression rate of the formulated product remains above 95 %. Furthermore, the contact angle between CPPS and the coal cake is reduced by 34 % in comparison to traditional dust suppressants. After 9 h, the water retention of the coal sample treated with CPPS stabilizes at approximately 18 %. Simulations using Materials Studio software indicate that CPPS enhances the infiltration of water molecules into coal dust and improves the adhesion between water and coal dust. This research is significant for the advancement of environmentally friendly composite dust suppressants and supports sustainable environmental practices.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"466 ","pages":"Article 121477"},"PeriodicalIF":4.6,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144721487","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":"A novel technique for the preparation of iron carbide and titanium-rich material from vanadium‑titanium magnetite","authors":"Shaoqiang Liu,&nbsp;Dong Chen,&nbsp;Peng Li,&nbsp;Hongwei Guo,&nbsp;Wei Zhao,&nbsp;Yang Yang,&nbsp;Ao Xie","doi":"10.1016/j.powtec.2025.121469","DOIUrl":"10.1016/j.powtec.2025.121469","url":null,"abstract":"<div><div>Vanadium‑titanium magnetite (VTM) is a polymetallic iron ore that is typically difficult to process. In this study, a novel technology-based utilization of VTM as iron carbide concentrate and titanium-rich material by applying carburization roasting followed by magnetic separation is proposed. Under optimized conditions, an iron carbide concentrate assaying 86.43 % Fe and 5.23 % C with a corresponding iron recovery rate of 99.37 % and a titanium-rich material assaying 45.14 % TiO₂ with a corresponding titanium recovery rate of 79.97 % were prepared. Moreover, the carburization behavior and separation mechanism were revealed using X-ray diffractometer (XRD) and scanning electron microscope (SEM). The results show that the separation efficiency of iron carbide, titanium minerals and gangue was very low. The Na₂CO₃ additive and high temperature reduction treatment are effective measures to improve the separation efficiency as they can significantly increase the carburization efficiency, enlarge the iron carbide particle size, and improve the embedded relationship of gangue, titanium minerals and iron carbide. In addition, high temperature reduction treatment can enhance the reactions of Na₂CO₃ and titanium minerals. The study demonstrates that preparation of iron carbide and titanium-rich material from VTM using the proposed technology is a feasible method.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"466 ","pages":"Article 121469"},"PeriodicalIF":4.6,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144739349","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":"Effect of node-strengthened shape on mechanical properties of body-centered-cubic lattice structures fabricated by selective laser melting","authors":"Xiaoqing Zhang ,&nbsp;Yuwei Zhang ,&nbsp;Lijing Xie ,&nbsp;Wentian Shi ,&nbsp;Bo Liu","doi":"10.1016/j.powtec.2025.121465","DOIUrl":"10.1016/j.powtec.2025.121465","url":null,"abstract":"<div><div>In response to the problem of stress concentration at the nodes of body-centered-cubic (BCC) lattice structures, three kinds of node-strengthened shapes are designed in this study. Ti-6Al-4 V and selective laser melting are used to prepare lattice structures with different strengthening degrees. Combined with quasi-static compression experiment and finite element analysis (FEA), the effects of rounded corner transition, solid ball reinforcement and truss element with variable cross-section characteristics on mechanical properties are investigated. The compressive properties, deformation behavior and stress distribution mechanism are studied and verified in this experiment. The results show that the enhancing effect of different node-strengthened modes is different. The truss element with variable cross-section characteristics shows the best ability to relieve stress concentration, and the equivalent elastic modulus and equivalent yield strength of BCC-V-3 structure are increased by 48.1 % and 19.6 %, respectively. By analyzing the mechanism of stress distribution, it is found that the node strengthening should focus on optimizing the concentration area of tensile stress which is easy to cause cracks, and the best strengthening degree of different node shapes is different, and the principle of obtaining a more uniform stress distribution should be taken as the criterion. In addition, the fracture gradually shifts to the middle of the strut with the increase of strengthening degree, and it is expected to realize the fracture mode of the lattice structures directionally designed.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"466 ","pages":"Article 121465"},"PeriodicalIF":4.6,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144767028","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":"Tribological properties of alkanes in confined systems; A molecular dynamics analysis of nano-powder compaction processes","authors":"A.R. Khoei ,&nbsp;P. Palahang ,&nbsp;A. Rezaei Sameti","doi":"10.1016/j.powtec.2025.121480","DOIUrl":"10.1016/j.powtec.2025.121480","url":null,"abstract":"<div><div>In this paper, the viscosity, structural arrangement, and tribological properties of straight-chain, branched-chain, and cyclic alkanes are investigated using non-equilibrium molecular dynamics simulations in confined systems. The viscosity is calculated at various shear rates and confinement pressures, and the results are validated with experimental data. It is shown that the non-Newtonian viscosity of lubricants has no significant dependence on the shear rate at low pressures. Accordingly, the Eyring model and averaging method are utilized to determine the Newtonian viscosity, in which the averaging method indicates a superior accuracy at low pressures. Moreover, the evolution of film thickness, density distribution, flow behavior, and friction phenomenon are studied for the three kinds of alkanes confined between the aluminum surfaces at different pressures and shear rates. Numerical results reveal that the peak of density increases by increasing the pressure and reducing the shear rate. Moreover, the solid-like behavior is observed at low shear rates and high pressures for cyclic-chain alkane, while the liquid-like behavior is dominant at high shear rates. The study concludes that the friction coefficient increases linearly with a logarithmic shear rate for all alkanes, such that its slope reduces by increasing the pressure. Finally, the effect of decane is investigated as the lubricant film on the die-wall friction through the nano-powder compaction processes. It is demonstrated that lubricants significantly reduce the coefficient of friction by 80 % to 95 %, stabilizing the compaction process and improving the quality of the final product.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"467 ","pages":"Article 121480"},"PeriodicalIF":4.6,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144771117","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}