Pub Date : 2025-03-02DOI: 10.1016/j.powtec.2025.120857
Yongli Ma , Jiaming Zhang , Hang Xiao , Mingyan Liu
The clustering behavior of solid particles in the riser of a gas-liquid-solid circulating fluidized bed significantly affects phase mixing, mass and heat transfer characteristics, but little work has been carried out on this topic. To fill this knowledge gap, we used an invasive telecentric photography to measure and investigate the axial and radial distributions of cluster characteristics of solid particles in the riser of the three-phase circulating fluidized bed. The results showed that at present experimental conditions, cluster size followed a log-normal distribution in the riser. Within the ranges of superficial gas, liquid and particle velocity of 5.6 × 10−3 to 11.2 × 10−3 m/s, 112 × 10−3 to 162 × 10−3 m/s, and 0.85 × 10−3 to 2 × 10−3 m/s (or auxiliary liquid velocity 20 × 10−3 to 50 × 10−3 m/s), respectively, 90 % of clusters consisted of about 2 solid particles, with sizes ranging from 0.7 mm to 1.2 mm. Cluster size and velocity increased with superficial liquid velocity, but they were less affected by superficial gas velocity and exhibited a radial structure. Particle aggregation by shedding vortices leads to the cluster formation.
{"title":"Clustering behavior of solid particles in gas-liquid-solid circulating fluidized beds studied by telecentric photography","authors":"Yongli Ma , Jiaming Zhang , Hang Xiao , Mingyan Liu","doi":"10.1016/j.powtec.2025.120857","DOIUrl":"10.1016/j.powtec.2025.120857","url":null,"abstract":"<div><div>The clustering behavior of solid particles in the riser of a gas-liquid-solid circulating fluidized bed significantly affects phase mixing, mass and heat transfer characteristics, but little work has been carried out on this topic. To fill this knowledge gap, we used an invasive telecentric photography to measure and investigate the axial and radial distributions of cluster characteristics of solid particles in the riser of the three-phase circulating fluidized bed. The results showed that at present experimental conditions, cluster size followed a log-normal distribution in the riser. Within the ranges of superficial gas, liquid and particle velocity of 5.6 × 10<sup>−3</sup> to 11.2 × 10<sup>−3</sup> m/s, 112 × 10<sup>−3</sup> to 162 × 10<sup>−3</sup> m/s, and 0.85 × 10<sup>−3</sup> to 2 × 10<sup>−3</sup> m/s (or auxiliary liquid velocity 20 × 10<sup>−3</sup> to 50 × 10<sup>−3</sup> m/s), respectively, 90 % of clusters consisted of about 2 solid particles, with sizes ranging from 0.7 mm to 1.2 mm. Cluster size and velocity increased with superficial liquid velocity, but they were less affected by superficial gas velocity and exhibited a radial structure. Particle aggregation by shedding vortices leads to the cluster formation.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"456 ","pages":"Article 120857"},"PeriodicalIF":4.5,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550819","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}
The present work investigates the dynamics of dust clouds in space and time when dispersed inside the modified Hartmann tube commonly used for explosibility screening and Minimum Ignition Energy (MIE) measurement. This study focuses on the fluid dynamics of the dust cloud in the space between the electrodes where the ignition occurs since fundamental properties of the dust motion, such as the cloud turbulence (intensity and variation), are known to affect both the ignition sensitivity and explosion severity significantly. An imaging re-elaboration method based on an algorithm (Image-Subtraction Method, ISM) is presented and adopted in the basics of the present research. To clarify the cloud dynamics, a novel approach is proposed here, using LabVIEW® specific algorithms, namely Particle Analysis and optical flow detection methods, which allow the tracking of the motion and the velocity vectors of dust clusters identified in the cloud flow. Concurrently, measuring the intensity of concentration changes between the electrodes (luminance change of the video frames in time and space) and cloud velocity, which likely represents the turbulence, is possible. Different types of dust (iron, starch, silica) were used at different dispersion conditions (dispersion pressure and dust amount). The cloud motion was recorded, and videos were analyzed through LabVIEW® to explore the parameters affecting dust turbulence (powder-specific gravity, particle size distribution, and air blast intensity). The outcomes of this work will help characterize the flow of a dust cloud inside a tube before its ignition and better define the optimal testing conditions for MIE determination.
{"title":"Uncovering turbulence of dust particles in the Hartmann tube through the Image-Subtraction Method","authors":"Luca Marmo , Olivier Dufaud , Fausto Franchini , Enrico Danzi","doi":"10.1016/j.powtec.2025.120871","DOIUrl":"10.1016/j.powtec.2025.120871","url":null,"abstract":"<div><div>The present work investigates the dynamics of dust clouds in space and time when dispersed inside the modified Hartmann tube commonly used for explosibility screening and Minimum Ignition Energy (MIE) measurement. This study focuses on the fluid dynamics of the dust cloud in the space between the electrodes where the ignition occurs since fundamental properties of the dust motion, such as the cloud turbulence (intensity and variation), are known to affect both the ignition sensitivity and explosion severity significantly. An imaging re-elaboration method based on an algorithm (Image-Subtraction Method, ISM) is presented and adopted in the basics of the present research. To clarify the cloud dynamics, a novel approach is proposed here, using LabVIEW® specific algorithms, namely Particle Analysis and optical flow detection methods, which allow the tracking of the motion and the velocity vectors of dust clusters identified in the cloud flow. Concurrently, measuring the intensity of concentration changes between the electrodes (luminance change of the video frames in time and space) and cloud velocity, which likely represents the turbulence, is possible. Different types of dust (iron, starch, silica) were used at different dispersion conditions (dispersion pressure and dust amount). The cloud motion was recorded, and videos were analyzed through LabVIEW® to explore the parameters affecting dust turbulence (powder-specific gravity, particle size distribution, and air blast intensity). The outcomes of this work will help characterize the flow of a dust cloud inside a tube before its ignition and better define the optimal testing conditions for MIE determination.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"457 ","pages":"Article 120871"},"PeriodicalIF":4.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143578105","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}
Pub Date : 2025-03-01DOI: 10.1016/j.powtec.2025.120872
Chengfang Yuan , Cheng Hu , Caibin Wu , Li Ling , Zongyan Zhou , Quan Li , Ziyu Zhou
The traditional model of closed circuit ball mill systems has been used for several decades, however, if the classifier of the closed circuit ball mill system performs the duties of both pre-classification and check-classification, the characterization error of the traditional model is large. To address this problem, a new model is proposed by modifying the traditional one. The results show that the new model characterizes the relative capacity of the ball mill more accurately, with a concentration of data at 65 % (classification efficiency) compared to the concentration of data at 50 % in the traditional model. The circulating load calculated by the new model is 360.81 %, and the corresponding slurry level in the ball mill is about 50 %, which is more consistent with the actual level. The new model has a higher accuracy than the traditional model in characterizing the production status of the grinding system, which is of some significance for industrial production.
{"title":"A new model for prediction of classification performance in closed circuit ball mill systems","authors":"Chengfang Yuan , Cheng Hu , Caibin Wu , Li Ling , Zongyan Zhou , Quan Li , Ziyu Zhou","doi":"10.1016/j.powtec.2025.120872","DOIUrl":"10.1016/j.powtec.2025.120872","url":null,"abstract":"<div><div>The traditional model of closed circuit ball mill systems has been used for several decades, however, if the classifier of the closed circuit ball mill system performs the duties of both pre-classification and check-classification, the characterization error of the traditional model is large. To address this problem, a new model is proposed by modifying the traditional one. The results show that the new model characterizes the relative capacity of the ball mill more accurately, with a concentration of data at 65 % (classification efficiency) compared to the concentration of data at 50 % in the traditional model. The circulating load calculated by the new model is 360.81 %, and the corresponding slurry level in the ball mill is about 50 %, which is more consistent with the actual level. The new model has a higher accuracy than the traditional model in characterizing the production status of the grinding system, which is of some significance for industrial production.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"457 ","pages":"Article 120872"},"PeriodicalIF":4.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143578104","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 : 2025-03-01DOI: 10.1016/j.powtec.2025.120868
J.J. Chen , G.X. Guan
A high packing density is essential to provide self-consolidating concrete (SCC) superior rheological performance. The superfine natural zeolite (SNZ), ground from natural zeolite to have a size finer than cement, can fill the voids between cement grains for packing density improvement. To evaluate the effect of SNZ on rheological properties and the effect of this change in rheological properties on flowability, a total of 28 concrete mixes with different SNZ contents at different paste volume were produced to test yield stress, apparent viscosity, pseudoplastic index, slump-flow and flow rate. The roles of yield stress and apparent viscosity on flowability of SNZ concrete were quantified. And, to reveal the causes of these effects of SNZ on rheological properties and flowability, the changes in packing density and film thicknesses of the concrete mixes were measured. The results disclosed that the effect of SNZ on rheological properties was dependent on the SNZ content and the paste volume. The SNZ affected the flowability through film thicknesses and consequently through rheological properties, and affected the pseudoplastic index mainly through packing density. Addition of 10 % SNZ increased the strength, decreased yield stress and apparent viscosity and slightly increased pseudoplastic index. It is concluded that SNZ has a potential to improve rheological properties to produce high-strength SCC.
{"title":"Addition of superfine natural zeolite to improve rheological properties of self-consolidating concrete","authors":"J.J. Chen , G.X. Guan","doi":"10.1016/j.powtec.2025.120868","DOIUrl":"10.1016/j.powtec.2025.120868","url":null,"abstract":"<div><div>A high packing density is essential to provide self-consolidating concrete (SCC) superior rheological performance. The superfine natural zeolite (SNZ), ground from natural zeolite to have a size finer than cement, can fill the voids between cement grains for packing density improvement. To evaluate the effect of SNZ on rheological properties and the effect of this change in rheological properties on flowability, a total of 28 concrete mixes with different SNZ contents at different paste volume were produced to test yield stress, apparent viscosity, pseudoplastic index, slump-flow and flow rate. The roles of yield stress and apparent viscosity on flowability of SNZ concrete were quantified. And, to reveal the causes of these effects of SNZ on rheological properties and flowability, the changes in packing density and film thicknesses of the concrete mixes were measured. The results disclosed that the effect of SNZ on rheological properties was dependent on the SNZ content and the paste volume. The SNZ affected the flowability through film thicknesses and consequently through rheological properties, and affected the pseudoplastic index mainly through packing density. Addition of 10 % SNZ increased the strength, decreased yield stress and apparent viscosity and slightly increased pseudoplastic index. It is concluded that SNZ has a potential to improve rheological properties to produce high-strength SCC.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"456 ","pages":"Article 120868"},"PeriodicalIF":4.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550818","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 : 2025-03-01DOI: 10.1016/j.powtec.2025.120869
Jiacheng Zhou , Fei Liu , Libin Zhang , Liuyang Chen , Xuesong Wang , Chenlong Duan , Haishen Jiang , Miao Pan
To increase the accuracy of simulation parameters for wet irregular particles and investigate the interaction mechanisms between wet particles, the parameters for three types of irregular wet particles are calibrated and validated. Firstly, the models for the three types of wet irregular particles are constructed, and the corresponding stacking angles are obtained. Then, the linear regression equation between the significant parameters and the particle stacking angle is established to validate the relative errors. The results showed that the relative errors for the simulated and experimental stacking angles of the capsule, cassia seed, and colored sand particles are 1.83 %, 1.51 %, and 2.23 %, respectively. These relative errors are lower than those reported in existing literature. Moreover, particle fluidity tests are conducted to explore the particle interaction mechanisms. The results indicate that the smooth and hydrophilic particle surfaces are more likely to accumulate water molecules and form liquid bridges, which lead to enhanced adhesion and decreased particle fluidity. On the contrary, the liquid bridge is more prone to fracture on a rough and hydrophobic particle surface, which leads to decreased adhesion and enhanced particle fluidity. The study demonstrates that this parameter calibration method and the interaction mechanisms of wet irregular particles are reliable.
{"title":"Research on the parameter calibration and the interaction mechanisms of irregular wet particles","authors":"Jiacheng Zhou , Fei Liu , Libin Zhang , Liuyang Chen , Xuesong Wang , Chenlong Duan , Haishen Jiang , Miao Pan","doi":"10.1016/j.powtec.2025.120869","DOIUrl":"10.1016/j.powtec.2025.120869","url":null,"abstract":"<div><div>To increase the accuracy of simulation parameters for wet irregular particles and investigate the interaction mechanisms between wet particles, the parameters for three types of irregular wet particles are calibrated and validated. Firstly, the models for the three types of wet irregular particles are constructed, and the corresponding stacking angles are obtained. Then, the linear regression equation between the significant parameters and the particle stacking angle is established to validate the relative errors. The results showed that the relative errors for the simulated and experimental stacking angles of the capsule, cassia seed, and colored sand particles are 1.83 %, 1.51 %, and 2.23 %, respectively. These relative errors are lower than those reported in existing literature. Moreover, particle fluidity tests are conducted to explore the particle interaction mechanisms. The results indicate that the smooth and hydrophilic particle surfaces are more likely to accumulate water molecules and form liquid bridges, which lead to enhanced adhesion and decreased particle fluidity. On the contrary, the liquid bridge is more prone to fracture on a rough and hydrophobic particle surface, which leads to decreased adhesion and enhanced particle fluidity. The study demonstrates that this parameter calibration method and the interaction mechanisms of wet irregular particles are reliable.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"457 ","pages":"Article 120869"},"PeriodicalIF":4.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143562420","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 : 2025-03-01DOI: 10.1016/j.powtec.2025.120866
Haiyan Liu , Xianmei He , Lingyu Wu , Qiang Liu , Xiaoxuan Fan , Xuefei Lu
In engineering applications, multi-compartment silos are employed to store and distribute various types of cement efficiently. In this paper, a three compartment silo with a diameter of 25 m and a height of 50 m is taken as the prototype. Based on it, two silo models are designed: a flat - bottomed model (Model 1) and an inverted cone bottomed model (Model 2). Both models have a diameter of 1 m and a height of 2 m. Cement static-discharging tests were carried out. The results showed that the deviation of static lateral pressure from Janssen's theory after fitting the two models was less than 10 %. Model 2 shows greater material inhomogeneity. During discharging, the lateral pressure peaks exhibit no obvious pattern, and a significant percentage of the lateral pressure peaks occur during the mass flow phase (98.8 % for Model 1 and 97.4 % for Model 2). Analyzing discharge side pressures using over-pressure coefficients has limitations. The revised lateral pressure formulas for three - compartment silos according to Chinese, European, and American standards are presented, and a lateral pressure calculation model is established.
{"title":"Experimental study on static and discharge lateral pressure of three-compartment cement silo wall","authors":"Haiyan Liu , Xianmei He , Lingyu Wu , Qiang Liu , Xiaoxuan Fan , Xuefei Lu","doi":"10.1016/j.powtec.2025.120866","DOIUrl":"10.1016/j.powtec.2025.120866","url":null,"abstract":"<div><div>In engineering applications, multi-compartment silos are employed to store and distribute various types of cement efficiently. In this paper, a three compartment silo with a diameter of 25 m and a height of 50 m is taken as the prototype. Based on it, two silo models are designed: a flat - bottomed model (Model 1) and an inverted cone bottomed model (Model 2). Both models have a diameter of 1 m and a height of 2 m. Cement static-discharging tests were carried out. The results showed that the deviation of static lateral pressure from Janssen's theory after fitting the two models was less than 10 %. Model 2 shows greater material inhomogeneity. During discharging, the lateral pressure peaks exhibit no obvious pattern, and a significant percentage of the lateral pressure peaks occur during the mass flow phase (98.8 % for Model 1 and 97.4 % for Model 2). Analyzing discharge side pressures using over-pressure coefficients has limitations. The revised lateral pressure formulas for three - compartment silos according to Chinese, European, and American standards are presented, and a lateral pressure calculation model is established.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"457 ","pages":"Article 120866"},"PeriodicalIF":4.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551949","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 : 2025-03-01DOI: 10.1016/j.powtec.2025.120856
Yong Zheng , Haizhu Wang , Hai Huang , Jun Ni , Bin Wang , Bing Yang , Wentong Zhang
Supercritical CO2 fracturing is a reservoir stimulation technology with broad application prospects, and the effective placement of proppant in the rough fracture network produced by fracturing is the key to determining the stimulation effect of the operating wells. In this study, an experimentally validated computational fluid dynamics-discrete element method (CFD-DEM) model is used to simulate supercritical CO2 transport proppant in a rough fracture network. The results show that in rough fracture networks, the use of small-sized proppant (0.2 mm) or low-density proppant (1250 kg/m3) significantly increases the amount of proppant within branching fractures, as well as the transport distance. Combination injection gives better proppant dune placement compared to single type of proppant injection, where the pumping schedule of larger and then smaller proppant sizes is effective in increasing propping of branching fracture. The efficacy of pulse injection in enhancing proppant transport distance using supercritical CO2 is significantly constrained by the absence of suitable fiber materials.
{"title":"CFD-DEM simulation of proppant transport under variable injection strategies in rough fracture network with supercritical CO2","authors":"Yong Zheng , Haizhu Wang , Hai Huang , Jun Ni , Bin Wang , Bing Yang , Wentong Zhang","doi":"10.1016/j.powtec.2025.120856","DOIUrl":"10.1016/j.powtec.2025.120856","url":null,"abstract":"<div><div>Supercritical CO<sub>2</sub> fracturing is a reservoir stimulation technology with broad application prospects, and the effective placement of proppant in the rough fracture network produced by fracturing is the key to determining the stimulation effect of the operating wells. In this study, an experimentally validated computational fluid dynamics-discrete element method (CFD-DEM) model is used to simulate supercritical CO<sub>2</sub> transport proppant in a rough fracture network. The results show that in rough fracture networks, the use of small-sized proppant (0.2 mm) or low-density proppant (1250 kg/m<sup>3</sup>) significantly increases the amount of proppant within branching fractures, as well as the transport distance. Combination injection gives better proppant dune placement compared to single type of proppant injection, where the pumping schedule of larger and then smaller proppant sizes is effective in increasing propping of branching fracture. The efficacy of pulse injection in enhancing proppant transport distance using supercritical CO<sub>2</sub> is significantly constrained by the absence of suitable fiber materials.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"457 ","pages":"Article 120856"},"PeriodicalIF":4.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143578158","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 : 2025-03-01DOI: 10.1016/j.powtec.2025.120863
Yupeng Feng , Xin Liu , Zilin Song , Tong Liu , Zixu Liu , Peifu Xiao , Tian Yin , Yu Zhang , Haibing He , Jingxin Gou , Yanjiao Wang , Xing Tang
In this study, the fluidized crystal coating (FCC) method was proposed to prepare aspirin sustained-release capsules (ASC). The properties of aspirin crystals and their respective coating solutions were systematically investigated. Additionally, the crystal properties of aspirin (ASP) were analyzed by evaluating the contact angle and solid surface characteristics. The surface energy of the crystals before and after the coating process was also measured, providing essential insights into the preparation process. Pellets with coating weight gains of 2 % to 4 % (Part A) and 14 % to 17 % (Part B) were mixed in a 3:7 ratio to obtain the ASC. The resulting ASC exhibited a clear sustained-release effect. Nanoindentation experiments offered critical data supporting the FCC coating process and provided practical guidance for the operation of the coating process. Furthermore, Raman spectroscopy and TEM were employed to investigate the structure of the coated crystals. DSC and XRD analyses confirmed that the aspirin crystals did not undergo any crystallographic changes during the process. The combined results of these experiments demonstrate that the preparation of ASC using the FCC method is feasible and provides a new approach for the FCC coating process.
{"title":"Achieved fluidized crystal coating of aspirin by ensuring core stability and minimizing drug migration within the sustained layer","authors":"Yupeng Feng , Xin Liu , Zilin Song , Tong Liu , Zixu Liu , Peifu Xiao , Tian Yin , Yu Zhang , Haibing He , Jingxin Gou , Yanjiao Wang , Xing Tang","doi":"10.1016/j.powtec.2025.120863","DOIUrl":"10.1016/j.powtec.2025.120863","url":null,"abstract":"<div><div>In this study, the fluidized crystal coating (FCC) method was proposed to prepare aspirin sustained-release capsules (ASC). The properties of aspirin crystals and their respective coating solutions were systematically investigated. Additionally, the crystal properties of aspirin (ASP) were analyzed by evaluating the contact angle and solid surface characteristics. The surface energy of the crystals before and after the coating process was also measured, providing essential insights into the preparation process. Pellets with coating weight gains of 2 % to 4 % (Part A) and 14 % to 17 % (Part B) were mixed in a 3:7 ratio to obtain the ASC. The resulting ASC exhibited a clear sustained-release effect. Nanoindentation experiments offered critical data supporting the FCC coating process and provided practical guidance for the operation of the coating process. Furthermore, Raman spectroscopy and TEM were employed to investigate the structure of the coated crystals. DSC and XRD analyses confirmed that the aspirin crystals did not undergo any crystallographic changes during the process. The combined results of these experiments demonstrate that the preparation of ASC using the FCC method is feasible and provides a new approach for the FCC coating process.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"456 ","pages":"Article 120863"},"PeriodicalIF":4.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550814","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 : 2025-03-01DOI: 10.1016/j.powtec.2025.120837
Zongbao Han , Yunli Wang , Weilin Xu
In this study, a method was employed to treat cotton fabrics with a mixed calcium hydroxide/ethanol/water solution system following the introduction of carbon dioxide, facilitating the in-situ deposition of nano calcium carbonate (NCC) on the cotton fibers. The findings revealed that the NCC particles formed on the fibers exhibit a diamond-shaped cubic morphology, characteristic of the calcite crystal type, with dimensions ranging from tens to hundreds of nanometers. The addition of ethanol contributes to the formation of NCC, with a maximum increase of about 2 times in calcium element content. The breaking strength of the cotton fabric was notably enhanced after deposition, with the addition of ethanol resulting in an approximate 8–10 % increase in breaking strength, much higher than that of sample without ethanol (∼ 4.2 %). The deposition modification did not significantly alter the chemical or crystalline structure of the cotton fibers. Additionally, the crystallization index of the fibers was improved to a certain degree, without compromising their hydrophilicity, thus not affecting subsequent dyeing and finishing processes. This has introduced a novel avenue for researchers to investigate and enhance the physical and mechanical properties of cotton fiber materials, which is beneficial for expanding their application fields.
{"title":"Effect of ethanol on in-situ deposition of nano calcium carbonate on cotton fibers","authors":"Zongbao Han , Yunli Wang , Weilin Xu","doi":"10.1016/j.powtec.2025.120837","DOIUrl":"10.1016/j.powtec.2025.120837","url":null,"abstract":"<div><div>In this study, a method was employed to treat cotton fabrics with a mixed calcium hydroxide/ethanol/water solution system following the introduction of carbon dioxide, facilitating the in-situ deposition of nano calcium carbonate (NCC) on the cotton fibers. The findings revealed that the NCC particles formed on the fibers exhibit a diamond-shaped cubic morphology, characteristic of the calcite crystal type, with dimensions ranging from tens to hundreds of nanometers. The addition of ethanol contributes to the formation of NCC, with a maximum increase of about 2 times in calcium element content. The breaking strength of the cotton fabric was notably enhanced after deposition, with the addition of ethanol resulting in an approximate 8–10 % increase in breaking strength, much higher than that of sample without ethanol (∼ 4.2 %). The deposition modification did not significantly alter the chemical or crystalline structure of the cotton fibers. Additionally, the crystallization index of the fibers was improved to a certain degree, without compromising their hydrophilicity, thus not affecting subsequent dyeing and finishing processes. This has introduced a novel avenue for researchers to investigate and enhance the physical and mechanical properties of cotton fiber materials, which is beneficial for expanding their application fields.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"456 ","pages":"Article 120837"},"PeriodicalIF":4.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550817","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 : 2025-02-28DOI: 10.1016/j.powtec.2025.120834
Weizhou Quan, Mamadou Fall
Cemented paste backfill (an engineered mixture of tailings, binder, and water), as one of the sustainable technological innovations for mining waste management, is used extensively around the world as a cementitious construction material in underground mines. The induced cracks within the CPB material tend to severely weaken the integrity and mechanical strength of the CPB structures as well as increase their permeability properties, undermining their safety, serviceability, durability, and environmental performance. However, no studies have been conducted to investigate the autogenous self-healing capability and behaviour of CPB. Therefore, this paper presents the results of an experimental study on the autogenous healing behaviour in CPB material to understand the self-healing mechanism and evaluate the self-healing efficiency through the recovery of mechanical and permeation properties. To this end, the CPB specimens were pre-damaged at different initial curing periods (i.e., 3, 7, and 28 days) and at different pre-damage levels (i.e., 30 %, 50 %, 75 %, 90 %, or 100 % of ultimate compressive strength in the pre-peak phase); then cured with self-healing periods of 1, 7, 28 or 90 days. Mechanical and hydraulic conductivity tests were performed on the pre-damaged specimens to monitor the self-healing changes. The results demonstrate that a significant self-healing capability does exist in the CPB materials due to the formed self-healing products from continuous cement hydration interior of the CPB matrix and carbonation of calcium hydroxide. The mechanical strength and hydraulic conductivity of pre-damaged specimens can be restored to similar values of the control specimens after 7 days and 28 days of self-healing periods, respectively. Furthermore, the study also reveals that the CPB specimens with high pre-damage levels (i.e., 75 %, 90 %, or 100 %) can even achieve up to 42 % higher mechanical strengths than the control specimens after 90 days of the self-healing period, indicating that the initiated cracks within the CPB matrix can ameliorate the hydration reactions favoring the self-healing performance. The results presented in the paper would have significant impacts and practical implications with respect to CPB structure design, mechanical stability, and durability.
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