Grinding of Class-F fly ash using planetary ball mill: A simulation study to determine the breakage kinetics by direct- and back-calculation method

Rajak, Dilip Kumar; Raj, Alex Noel Joseph; Guria, Chandan; Pathak, Akhilesh Kumar

doi:10.1016/j.sajce.2017.08.002

Cited by 12 publications

(3 citation statements)

References 32 publications

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“…These changes occur both inside the body in the entire volume and on the surface of the substance as a result of high-energy grinding in a mill [42,43]. For example, mechanical activation of fly ash is aimed to increase the amorphous content [44], and enlarge the specific surface area and fineness [45].…”

Section: Particle Sizementioning

confidence: 99%

Concrete Modification for Hot Weather Using Crushed Dolomite Stone

Samchenko,

Larsen,

Kozlova

et al. 2023

Buildings

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Crushed dolomite stone can be used as a part of concrete for hot weather. Fine dolomite as a filler is not commonly included in Portland cement. In this paper, the properties of a blended binder based on Portland cement and dolomite filler are presented. Dolomite filler was obtained from dust grains by mechanical activation in a laboratory ball mill to increase the specific surface area and its chemical activity. It is shown that the impact of mechanical activation allows to obtain dolomite filler with a median particle size of 1.4 μm and a specific surface area of 639.9 m2/kg. The content of dolomite filler in Portland cement was 10, 30 and 50%. The main properties of blended cements, i.e., the standard consistency, setting time, compressive strength, average density, and drying shrinkage, were determined on pastes. The mineralogical composition of the hydrated pastes was determined by XRD at 28 days. The presence of dolomite filler at levels higher than 10% decreases the compressive strength of blended cements. The dolomite filler decreases the water demand, shortens the setting time, and mitigates the development of drying shrinkage in the blended binder. To prevent concrete cracking, the application of dolomite filler in blended cement is relevant in hot weather due to its reduced drying shrinkage.

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Section: Particle Sizementioning

confidence: 99%

Concrete Modification for Hot Weather Using Crushed Dolomite Stone

Samchenko,

Larsen,

Kozlova

et al. 2023

Buildings

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“…Figure 1 depicts the operational principle of the ball mill. Owing to their ability to increase surface energy and defect rates, as well as induce structural transformations and chemical reactions [34,35], planetary ball mills are commonly utilized for particle size reduction. During high-stress milling within the ball mill tank, spherical particles of FA undergo disintegration, causing a decrease in particle size and altering the structure of FA.…”

Section: Introductionmentioning

confidence: 99%

Effect of Precursor Blending Ratio and Rotation Speed of Mechanically Activated Fly Ash on Properties of Geopolymer Foam Concrete

Liu,

Jiang,

et al. 2024

Buildings

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This research used fly ash and slag to create geopolymer foam concrete. They were activated with an alkali, resulting in a chemical reaction that produced a gel that strengthened the concrete’s structural integrity. The experimental approach involved varying the fly ash content in the precursors at incremental percentages (10%, 30%, 50%, 70% and 90%) and subjecting the fly ash to mechanical activation through a planetary ball mill at distinct rotational speeds (380, 400, 420 and 440 rpm). The investigation discerned that the fly ash content and particle structure exert a discernible influence on macroscopic properties, including flowability, air generation height, compressive strength, dry density and microstructural characteristics such as pore distribution and hydration product arrangement in the geopolymer foam concrete. Employing analytical techniques such as X-ray diffraction (XRD) and scanning electron microscopy (SEM), it was deduced that diminishing the fly ash content correlates with an enhancement in compressive strength. Furthermore, the specific strength of the geopolymer foam concrete reached a peak of 0.041 when the activated fly ash in the planetary ball mill rotated at 420 rpm, manifesting a lightweight and high-strength outcome.

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“…Such mechanical activation not only improves degree of fineness but also involves breaking of bonds, dispersion of particles, generation and migration of chemical components in the bulk, thus results in increased surface roughness and specific surface area [19]. Rajak et al [20] studied dry grinding of Class-F fly ash was milled using the planetary ball mill to produce mechanically activated particles. The specific surface area of milled fly ash was increased from 7.31 m 2 g -1 to 28.08 m 2 g -1 resulting fine grinding, whereas crystallinity of fly ash and crystallite size of quartz in glass phase was decreased by 26.12% and 40.1%, respectively.…”

Section: Introductionmentioning

confidence: 99%

Mechanical Activation of Fly Ash: Physical, Mineralogical and Morphological Characterization of Ground Fly Ashes

Dikmen¹,

Dikmen²,

Yilmaz

et al. 2019

Eskişehir Technical University Journal of Science and Technology a - Applied Sciences and Engineering

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In this study, physical, mineralogical and morphological characteristics of mechanically treated fly ashes are investigated. The compositional analysis of the raw fly ash was determined using X-ray fluorescence (XRF) technique. The XRD patterns reveal that the main phase quartz along with mullite and anhydrite. The raw fly ash was also wet ground using a laboratory mill, for several different times (from 2 to 16 hours) in order to examine how the grinding increases the activity of the fly ash. The ground fly ash was characterized for (i) particle size distribution: laser diffraction method, (ii) specific surface area: BETmethod, (iii) crystalline structure: X-ray diffractometer, and (iv) morphology of particles: scanning electron microscope. According to physical characterization, fineness increasing of samples with grinding time was observed, but loss of effectiveness occurred for grinding time longer than 12 hours. In addition, the unmilled fly ash showed lower specific surface area, due to the presence of cenospheres in the original fly ash. Only a little change in crystalline structure of fly ashes was observed when grinding and there were changes in the area and height of each diffraction peak.

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Grinding of Class-F fly ash using planetary ball mill: A simulation study to determine the breakage kinetics by direct- and back-calculation method

Cited by 12 publications

References 32 publications

Concrete Modification for Hot Weather Using Crushed Dolomite Stone

Concrete Modification for Hot Weather Using Crushed Dolomite Stone

Effect of Precursor Blending Ratio and Rotation Speed of Mechanically Activated Fly Ash on Properties of Geopolymer Foam Concrete

Mechanical Activation of Fly Ash: Physical, Mineralogical and Morphological Characterization of Ground Fly Ashes

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