Powder TechnologyPub Date : 2025-03-28DOI: 10.1016/j.powtec.2025.120988
Qiang Gao , Xi-guang Li , Xiao-dong Shi , Xin-long Li , Xian-jun Lyu , Xiang-nan Zhu , Yang-guang Ren
{"title":"Clean and high-value recycling approach for waste concrete powder: Mechano-chemical activation of pozzolanic activity","authors":"Qiang Gao , Xi-guang Li , Xiao-dong Shi , Xin-long Li , Xian-jun Lyu , Xiang-nan Zhu , Yang-guang Ren","doi":"10.1016/j.powtec.2025.120988","DOIUrl":"10.1016/j.powtec.2025.120988","url":null,"abstract":"<div><div>With the precipitous advancement of the construction industry, the resource utilization of construction waste has attracted extensive attention worldwide. In this study, the effect of mechano-chemical coupling activation on the activation of recycled concrete powder (RCP) pozzolanic activity was explored. Firstly, the effect of mechanical activation on the particle size characteristics and specific surface area (SSA) of RCP was analyzed. The D<sub>50</sub> of RCP attains 7.03 μm and the SSA reaches 1429.8 m<sup>2</sup>/kg after 120 min of grinding, indicating that mechanical activation enhanced the reactivity of RCP. Subsequently, the effects of mechanical activation time and alkali activation on the macroscopic properties of recycled concrete powder-based geopolymer (RCBG) were analyzed to indirectly determine the pozzolanic reactivity of RCP. The maximum compressive strength of RCBG can reach 4.475 MPa at 28 d when the RCP is milled for 120 min and the addition amounts of both CaO and CaSO₄ are 5 %. The pozzolanic activity of RCP is positively correlated with the mechanical milling time, and the excessive addition of alkali activators is detrimental to the development of compressive strength. Conclusively, X-ray diffraction (XRD), thermogravimetric-differential thermogravimetric (TG-DTG), and high-resolution scanning electron microscopy-energy spectroscopy (SEM-EDS) were used to analyze the hydration mechanism of RCBG. XRD and TG analyses show that the presence of CaO and CaSO<sub>4</sub> is favorable to increase the generation amount of hydration products (C-(A)-S-H gel and ettringite), and dense microstructures are formed, thus improving the strength of RCBG.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"458 ","pages":"Article 120988"},"PeriodicalIF":4.5,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747995","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}
Powder TechnologyPub Date : 2025-03-28DOI: 10.1016/j.powtec.2025.120991
Chao Zhang , Sadaf Maramizonouz , Changrong Yang , David Milledge , Roger Lewis , Sadegh Nadimi
{"title":"Electro-mechanical insights into the mixing of conductive and non-conductive sands at an interface","authors":"Chao Zhang , Sadaf Maramizonouz , Changrong Yang , David Milledge , Roger Lewis , Sadegh Nadimi","doi":"10.1016/j.powtec.2025.120991","DOIUrl":"10.1016/j.powtec.2025.120991","url":null,"abstract":"<div><div>This paper investigates the electrical behaviour of an electrically conductive sand particle when mixed with non-conductive silica sand, commonly used in the railway industry. Laboratory tests and numerical simulations are conducted to assess the effect of mixing on the electrical conduction properties at the metal-to-metal interface under mechanical loading. Results from compression tests demonstrate that mixing with even 5 % mass of conductive particles can significantly reduce electrical resistance at the interface; however, the decrease in electrical resistance gradually slows down when the mixing ratio of conductive particles exceeds 10 %. Discrete element modelling of high pressure torsion tests – enhanced with a newly proposed electro-mechanical contact model – reveal that fine conductive particles are more effective than coarse particles in reducing interfacial electrical resistance at equal mixing ratios. A heatmap is proposed to estimate the percentage of conductive particles required to bring the resistance of the interface below the critical threshold of 10 Ω for track circuit, which links the resistivity of various conductive particles with their required mixing ratio.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"458 ","pages":"Article 120991"},"PeriodicalIF":4.5,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Powder TechnologyPub Date : 2025-03-28DOI: 10.1016/j.powtec.2025.120985
Sean Garner , Stewart Silling , John Strong , William Ketterhagen
{"title":"A novel peridynamics-based approach to predict pharmaceutical tablet robustness","authors":"Sean Garner , Stewart Silling , John Strong , William Ketterhagen","doi":"10.1016/j.powtec.2025.120985","DOIUrl":"10.1016/j.powtec.2025.120985","url":null,"abstract":"<div><div>The pharmaceutical drug product development process can be greatly accelerated through the use of modeling and simulation techniques to predict the manufacturability and performance of a given formulation. The anticipation and possible mitigation of tablet damage due to manufacturing stresses represents a specific area of interest in the pharmaceutical industry for predicting formulation and tableting performance. While the finite element method (FEM) has been extensively used for predicting the mechanical behavior of powder material in the compaction processes, a shortcoming of the approach is the inherent difficulty to predict discontinuities (e.g., damage or cracking) within a tablet as FEM is a continuum-based approach. In this work, we propose a novel method utilizing peridynamics (PD), a numerical method that can capture discontinuities such as tablet fracture, to predict the evolution of damage and breakage in pharmaceutical tablets. The approach links (1) the finite element method – to elucidate the behavior of powders during die compaction – with (2) the peridynamics modeling technique – to model the discontinuous nature of damage and predict tablet breakage during the critical stages of unloading and ejection from the compression die. This short communication presents a proof of concept including a workflow to calibrate the linked FEM-PD simulation models. It demonstrates promising results from a preliminary experimental validation of the approach. Following further development, this approach could be used to guide the optimization of compression processes through targeted changes to formulation material properties, compression process conditions, and/or tooling geometries to deliver improved process efficiency and tablet robustness.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"458 ","pages":"Article 120985"},"PeriodicalIF":4.5,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143777576","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}
Powder TechnologyPub Date : 2025-03-28DOI: 10.1016/j.powtec.2025.120994
Mingyu Chen , Xin Huang , Richard Lakerveld , Mingpu Yuan , Yifu Zhang , Shyam Lamichhane , Qiyun Luo , Jinshen Ren , Ting Wang , Na Wang , Hongxun Hao
{"title":"Computational fluid dynamics simulation of the hydrodynamic and particle suspension performance of a novel channel impeller","authors":"Mingyu Chen , Xin Huang , Richard Lakerveld , Mingpu Yuan , Yifu Zhang , Shyam Lamichhane , Qiyun Luo , Jinshen Ren , Ting Wang , Na Wang , Hongxun Hao","doi":"10.1016/j.powtec.2025.120994","DOIUrl":"10.1016/j.powtec.2025.120994","url":null,"abstract":"<div><div>Impeller optimization is essential to improve the performance of stirred tanks, which are widely used in the chemical industry. In this study, a novel channel impeller was developed by eliminating blades from conventional impellers to optimize mixing efficiency. By employing Eulerian-Eulerian model and the standard k-ε turbulence model, the hydrodynamic and particle suspension performance of this novel impeller were compared with traditional impellers (pitched blade impeller, propeller, and Rushton). The results reveal that the novel impeller significantly reduces power consumption and power number, while generating a flow pattern characterized by strong radial flows and a complex multi-peak axial velocity profile. Moreover, regions of high turbulent kinetic energy and turbulent energy dissipation rate are more concentrated and symmetrical, thereby improving local mixing efficiency. Notably, the novel impeller achieves a more uniform pressure and stress distribution, offering potentially better fluid dynamics performance and greater durability in practical applications.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"458 ","pages":"Article 120994"},"PeriodicalIF":4.5,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738139","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}
Powder TechnologyPub Date : 2025-03-28DOI: 10.1016/j.powtec.2025.120992
Zhidong Tang , Shaokai Cheng , Peng Gao , Yuexin Han , Yanjun Li
{"title":"Study of mean residence time in novel U-type fluidized bed reactor: Model prediction and experimental validation","authors":"Zhidong Tang , Shaokai Cheng , Peng Gao , Yuexin Han , Yanjun Li","doi":"10.1016/j.powtec.2025.120992","DOIUrl":"10.1016/j.powtec.2025.120992","url":null,"abstract":"<div><div>Fluidized bed roasting exhibits excellent application prospects for processing refractory iron ores, with the residence time of hematite powders in reactor being a critical factor that affects roasted product quality. In this study, a model for the mean residence time of materials in a U-type reactor was established and validated through cold experiment system. The effects of fluidization chamber airflow, supply chamber airflow and delivery rate were explored with different particle size of hematite. The results showed that the mean residence time of hematite powders predicted by the model and obtained from the experimental data decreased gradually with the increase of the fluidization chamber airflow, supply chamber airflow, and delivery rate. 70 groups of mean residence times for different working conditions matched very well with the model-predicted, with an error margin of less than ±8.58 %, which confirmed the validity of the proposed model. This model holds significant importance for regulating and optimizing the operational parameters of hematite during suspension roasting.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"458 ","pages":"Article 120992"},"PeriodicalIF":4.5,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738141","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":"CFD-DEM analysis of gas-solid-solid three-phase flow in a moving bed pyrolysis reactor","authors":"Tong Zhang , Dongsheng Jiao , Xiaoyu Wang, Liangzhi Xia","doi":"10.1016/j.powtec.2025.120948","DOIUrl":"10.1016/j.powtec.2025.120948","url":null,"abstract":"<div><div>Pyrolysis is an effective method for the clean and resourceful utilization of oil sludge. A solid heat carrier moving bed pyrolysis process can efficiently pyrolyze oil sludge, and the introduction of carrier gas can reduce secondary cracking, resulting in high-quality pyrolysis products. The flow and mixing uniformity of oil sludge particles with the heat carriers, as well as the uniformity of carrier gas flow, directly impact the efficiency of oil sludge particle pyrolysis. In this study, the flow and mixing characteristics of gas-solid-solid three-phase fluid in a cold moving bed were investigated using the coupled discrete element method (DEM) with computational fluid dynamics (CFD) based on the Euler-Euler-Lagrange multiphase flow model. The results indicated that a higher the mass ratio of heat carriers to oil sludge particles leads to better mixing uniformity of the mixture, while a lower mass ratio results in better flow uniformity of the particles. An increase in the volume of carrier gas initially improves the uniformity of particle flow but subsequently deteriorates it; conversely, a smaller volume of carrier gas enhances the mixing uniformity of the mixture. A smaller mass ratio of the heat carriers and a smaller volume of carrier gas lead to a more uniform distribution of carrier gas flow within the moving bed. The optimal conditions were found to be a mass ratio of oil sludge particles to heat carriers of 1:1 and a carrier gas flow rate of 7.5 L/min, which yielded the best flow mixing effect for oil sludge particles.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"458 ","pages":"Article 120948"},"PeriodicalIF":4.5,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143748001","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}
Powder TechnologyPub Date : 2025-03-27DOI: 10.1016/j.powtec.2025.120956
Yuan Li , Manthan Varia , Marek Pawlik , Jiaqi Jin , Dirk van Zyl
{"title":"Influence of pH on copper tailings sedimentation: A systematic approach to analyzing differential settling","authors":"Yuan Li , Manthan Varia , Marek Pawlik , Jiaqi Jin , Dirk van Zyl","doi":"10.1016/j.powtec.2025.120956","DOIUrl":"10.1016/j.powtec.2025.120956","url":null,"abstract":"<div><div>This paper presents an experimental and theoretical approach to investigate the differential settling behavior of copper tailings suspensions under varying pH conditions. The influence of pH on particle aggregation and sedimentation was studied through batch settling tests, solids content and turbidity measurements, particle size distribution (PSD) profiling, and force analysis. Results from the conventional batch settling test demonstrated that increasing pH enhanced the drop velocity of the supernatant-suspension interface, primarily due to the increased particle aggregation, which formed larger or denser clusters as the fundamental settling unit. Force analysis, based on the solids content and turbidity results, revealed that higher pH conditions increased the hindrance ability of the suspension, suppressing differential settling by reducing the relative movement of particle species. PSD profiling validated these findings, showing that more large particles were retained in the settling zone and more fine particles were incorporated in the sediment. Microscopy observations further confirmed the influence of pH on the aggregation degree of the copper tailings particles. This study not only reveals the impact of pH on differential settling but also establishes a systematic approach for interpreting sedimentation data to understand the differential settling mechanism. The integration of experimental tools with theoretical analysis provides a transferable methodology applicable to various tailings suspensions.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"458 ","pages":"Article 120956"},"PeriodicalIF":4.5,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143776978","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}
Powder TechnologyPub Date : 2025-03-27DOI: 10.1016/j.powtec.2025.120962
Pengcheng Tian , Peng Gao , Zhidong Tang , Zhenyue Zhang , Jiahao He , Xiao Wang , Yuexin Han
{"title":"Optimization of grinding parameters and efficient separation of iron and rare earths from poor oxide ores in magnetic separation operation","authors":"Pengcheng Tian , Peng Gao , Zhidong Tang , Zhenyue Zhang , Jiahao He , Xiao Wang , Yuexin Han","doi":"10.1016/j.powtec.2025.120962","DOIUrl":"10.1016/j.powtec.2025.120962","url":null,"abstract":"<div><div>Grinding operations are necessary for the effective separation of all minerals. In this study, poor oxide ores from Bayan Obo were treated with pilot-scale HMPT technology, followed by a grinding test conducted in a laboratory ceramic stirring mill. The magnetic separation test effectively separates iron and rare earth minerals. Iron recovery was dependent on maximizing magnetite recovery, while rare earth elements (REEs) mainly existed in bastnaesite, parisite, and monazite, and they are associative with complexity. Based on the degree of liberation, the grade, and recovery of iron and REEs, the optimum grinding conditions were determined as follows: material ball ratio of 0.5, medium size ratio (3 mm: 4 mm: 5 mm = 2:5:3), stirring speed of 600 rpm, grinding concentration of 50 %, and medium filling rate of 35 %. When the grinding time was 25 min, the iron grade and recovery were 67.36 % and 92.71 %, respectively, and the grade and recovery attained for rare earth were 12.32 % and 91.69 %, respectively. This study provides theoretical guidance for optimizing industrial-scale grinding conditions and the efficient separation of iron and rare earth elements in the Bayan Obo ore, further reducing energy consumption and promoting green and sustainable technological development.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"458 ","pages":"Article 120962"},"PeriodicalIF":4.5,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143776981","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":"Automated dynamic image analysis for particle size and shape classification in three dimensions","authors":"Sadegh Nadimi , Vasileios Angelidakis , Sadaf Maramizonouz , Chao Zhang","doi":"10.1016/j.powtec.2025.120973","DOIUrl":"10.1016/j.powtec.2025.120973","url":null,"abstract":"<div><div>We introduce OCULAR, an innovative hardware and software solution for three-dimensional dynamic image analysis of micron-sized particles. Current state-of-the art instruments for dynamic image analysis are largely limited to two-dimensional imaging. However, extensive literature has demonstrated that relying on a single two-dimensional projection for particle characterisation can lead to inaccuracies in many applications. Existing three-dimensional imaging technologies, such as computed tomography, laser scanning, and orthophotography, are limited to static objects. These methods are often not statistically representative and come with significant post-processing requirements, as well as the need for specialised imaging and computing resources. OCULAR addresses these challenges by providing a cost-effective solution for imaging continuous particle streams using a synchronised array of optical cameras. Particle shape characterisation is achieved through the reconstruction of their three-dimensional surfaces. This paper details the OCULAR methodology, evaluates its repeatability, and compares its results against X-ray micro-computed tomography, highlighting its potential for efficient and reliable particle analysis.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"458 ","pages":"Article 120973"},"PeriodicalIF":4.5,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143725954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Powder TechnologyPub Date : 2025-03-26DOI: 10.1016/j.powtec.2025.120939
Xiubin Wang , Yinan Xie , Qian Wang , Hongliang Shang , Zhicheng Hu , Jiangang Ku , Zhengchang Shen
{"title":"Removal and separation of iron and carbon from kaolin: A review","authors":"Xiubin Wang , Yinan Xie , Qian Wang , Hongliang Shang , Zhicheng Hu , Jiangang Ku , Zhengchang Shen","doi":"10.1016/j.powtec.2025.120939","DOIUrl":"10.1016/j.powtec.2025.120939","url":null,"abstract":"<div><div>Kaolin, a versatile material, is widely utilized owing to its distinctive mineralogical characteristics, mineral morphology, and chemical and physical properties. Whiteness, a critical factor in determining the commercial value of kaolin, is significantly influenced by its impurities. Consequently, impurity removal from kaolin has emerged as a primary research focus. These studies have concentrated on enhancing kaolin’s whiteness by optimizing critical parameters and employing innovative separation techniques. On this basis, this article reviews various methods for removing and separating iron (free and structural) and carbon impurities from kaolin, detailing the technical principles, optimizing parameters, and elucidating the mechanistic features of different beneficiation methods.In addition, this paper discusses the merits and limitations of these methods and proposes potential future research directions. This paper aims to guide the selection and development of strategies for kaolin purification and the decontamination of other clay minerals.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"458 ","pages":"Article 120939"},"PeriodicalIF":4.5,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738244","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}