scholarly journals Influence of Particle Morphology of Ground Fly Ash on the Fluidity and Strength of Cement Paste

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 283
Author(s):  
Juntao Ma ◽  
Daguang Wang ◽  
Shunbo Zhao ◽  
Ping Duan ◽  
Shangtong Yang
Keyword(s):  
Particle Size ◽  
Fly Ash ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Cement Paste ◽  
Ball Mill ◽  
Particle Morphology ◽  
Spherical Particles ◽  
Grinding Process ◽  
And Performance

The grinding process has become widely used to improve the fineness and performance of fly ash. However, most studies focus on the particle size distribution of ground fly ash, while the particle morphology is also an important factor to affect the performance of cement paste. This article aims at three different kinds of ground fly ash from the ball mill and vertical mill, and the particle morphology is observed by scanning electron microscopy (SEM) to calculate the spherical destruction (the ratio of spherical particles broken into irregular particles in the grinding process of fly ash), which provides a quantification of the morphology change in the grinding process. The fluidity of cement paste and the strength of cement mortar are tested to study the relation of spherical destruction and fluidity and strength. The results show that the spherical destruction of ground fly ash in a ball mill is more than 80% and that in a vertical mill with a separation system is only 11.9%. Spherical destruction shows a significant relation with the fluidity. To different addition of ground fly ash, the fluidity of cement paste decreases with the increase of spherical destruction. To the strength of cement paste, particle size distribution and spherical destruction are both the key factors. Therefore, spherical destruction is an important measurement index to evaluate the grinding effect of the fly ash mill.

Modelling Particle Size Distribution of Residual Fly Ash from Pulverized Biomass Combustion

2021 ◽  
Vol 15 (1) ◽  
pp. 75-82
Author(s):  
Mingzi Xu ◽  
Changdong Sheng
Keyword(s):  
Particle Size ◽  
Fly Ash ◽  
Simple Model ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Particle Shape ◽  
Great Influence ◽  
Biomass Combustion ◽  
Ash Formation ◽  
Residual Ash

The present work aims to develop a simple model for describing the particle size distribution (PSD) of residual fly ash from pulverized biomass combustion. The residual ash formation was modelled considering the mechanism of fragmentation and coalescence. The influences of particle shape and stochastic fragmentation on model description of the PSD of the fly ash were investigated. The results showed that biomass particle shape has a great influence on the model prediction, and a larger fragmentation number is required for cylindrical particles than that for spherical particles to get the same PSD of fly ash, and the fragment number of the particles increases with the shape factor increasing. For pulverized biomass with a wide size distribution, the model predicted ash PSD considering the stochastic fragmentation is very similar to that assuming uniform fragmentation. It implies that the simple model assuming uniform fragmentation is applicable for predicting fly ash size distribution in practical processes where biomass particles have a wide range of sizes. For the fuel with a narrower initial PSD, the stochastic fragmentation model generally predicts a coarser PSD of the residual ash than assuming uniform fragmentation. It means the stochastic fragmentation is of great influence to be considered for accurate description of ash formation from the fuel with a narrow PSD.

INFLUENCE OF METAL POWDER PRODUCTION METHOD ON MICROSTRUCTURE AND FLUIDITY OF MAGNETICALLY ALLOY GRANULATE

2021 ◽  
Vol 2021 (9) ◽  
pp. 3-7
Author(s):  
Dmitriy Kostin ◽  
Aleksandr Amosov ◽  
Anatoliy Samboruk ◽  
Bogdan Chernyshev ◽  
Anton Kamynin
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Comparative Studies ◽  
Particle Morphology ◽  
Production Method ◽  
Magnetic Alloy ◽  
Gas Atomization ◽  
Metal Powders ◽  
Hard Magnetic Alloy

A comparison is made of the characteristics of metal powders of a hard magnetic alloy produced by centrifugal spraying and gas atomization. Comparative studies of particle morphology and particle size distribution of powders are presented in order to determine them.

scholarly journals Influence of Particle Size Distribution of High Calcium Fly Ash on HVFA Mortar Properties

2018 ◽  
Vol 20 (2) ◽  
pp. 51
Author(s):  
Antoni . ◽  
Hendra Surya Wibawa ◽  
Djwantoro Hardjito
Keyword(s):  
Particle Size ◽  
Compressive Strength ◽  
Fly Ash ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Setting Time ◽  
High Volume ◽  
High Volume Fly Ash ◽  
High Calcium ◽  
High Calcium Fly Ash

This study evaluates the effect of particle size distribution (PSD) of high calcium fly ash on high volume fly ash (HVFA) mortar characteristics. Four PSD variations of high calcium fly ash used were: unclassified fly ash and fly ash passing sieve No. 200, No. 325 and No. 400, respectively. The fly ash replacement ratio of the cementitious material ranged between 50-70%. The results show that with smaller fly ash particles size and higher levels of fly ash replacement, the workability of the mixture was increased with longer setting time. There was an increase in mortar compressive strength with finer fly ash particle size, compared to those with unclassified ones, with the highest strength was found at those with fly ash passing mesh No. 325. The increase was found due to better compactability of the mixture. Higher fly ash replacement reduced the mortar’s compressive strength, however, the rate was reduced when finer fly ash particles was used.

Prediction of Packing Density of Milled Powder Based on Packing Simulation and Particle Shape Analysis

2007 ◽  
Vol 534-536 ◽  
pp. 1621-1624
Author(s):  
Yuto Amano ◽  
Takashi Itoh ◽  
Hoshiaki Terao ◽  
Naoyuki Kanetake
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Shape Analysis ◽  
Packing Density ◽  
Particle Shape ◽  
Milled Powder ◽  
Spherical Particles ◽  
Nonspherical Particles ◽  
Property Control

For precise property control of sintered products, it is important to know the powder characteristics, especially the packing density of the powder. In a previous work, we developed a packing simulation program that could make a packed bed of spherical particles having particle size distribution. In order to predict the packing density of the actual powder that consisted of nonspherical particles, we combined the packing simulation with a particle shape analysis. We investigated the influence of the particle size distribution of the powder on the packing density by executing the packing simulation based on particle size distributions of the actual milled chromium powders. In addition, the influence of the particle shape of the actual powder on the packing density was quantitatively analyzed. A prediction of the packing density of the milled powder was attempted with an analytical expression between the particle shape of the powder and the packing simulation. The predicted packing densities were in good agreement with the actual data.

A Model for Particle Size and Phase Distributions in Ground Cement Clinker

1986 ◽  
Vol 85 ◽  
Author(s):  
P. W. Brown ◽  
K. G. Galuk
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Cement Clinker ◽  
Grinding Process ◽  
Exposed Surface ◽  
Surface Areas

ABSTRACTA model has been developed to describe a granule of unground clinker, to simulate the grinding process by the removal of particles according to a user-defined particle size distribution, and to characterize the exposed surface areas and volumes of each clinker phase present. The composition of the clinker granule and the distribution of phases within the granule are also user defined.

Refractories containing fused and sintered alumina aggregates: Investigations on processing, particle size distribution and particle morphology

2017 ◽  
Vol 43 (5) ◽  
pp. 4252-4262 ◽  
Author(s):  
Stefan Schafföner ◽  
Christin Dietze ◽  
Steffen Möhmel ◽  
Jens Fruhstorfer ◽  
Christos G. Aneziris
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Particle Morphology
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