Measurement and Characterization of the Particle Size of Refractory Corundum

2013 ◽  
Vol 544 ◽  
pp. 135-138
Author(s):  
Fen Rong Yang ◽  
Kai Qi Liu ◽  
Bing Jun Wang ◽  
Xiao Hu Xie
Keyword(s):  
Particle Size ◽  
Size Distribution ◽  
Distribution Curve ◽  
Size Fraction ◽  
Powder Materials ◽  
Average Particle ◽  
Powder Particle Size ◽  
Size Frequency Distribution ◽  
Laser Particle Size Analyzer ◽  
Particle Size Analyzer

With introducing briefly the refractory powder materials, the article analyzed the morphology and particle size distribution of commercial different size fraction corundum powder by scanning electron microscopy and laser particle size analyzer. The results showed that most of corundum powder particles were angular spherical, Their particle volume average diameters D(4,3) are greater than median grain sizes D50, and with the difference increasing the distribution curve symmetry becomes worse. Moreover, size frequency distribution curve presents slanting unimodal or bimodal pattern, not completely normal distribution. Besides those, particle size ranges are very wide, e.g. the D90 of 15 μ m is 30 times larger than D10. Therefore, using only the average particle diameter indicates the powder is not comprehensive. The parameters and the size distribution cure measured by laser particle size analyzer can be detailed and accurate to reflect actual powder particle size and distribution, so using them as the commercial corundum powder specification values will be important to enhance the effective utilization of the powder.

scholarly journals Particle Size Distribution of the Coal Bottom Ash from the Large Combustion Plant

2015 ◽  
Vol 13 ◽  
pp. 210-215 ◽  
Author(s):  
Olimpia Ghermec ◽  
Ionela Gabriela Bucse ◽  
Mariana Ciobanu
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Bottom Ash ◽  
Size Fraction ◽  
Steam Boiler ◽  
Major Fraction ◽  
Coal Bottom Ash ◽  
Particle Size Analyzer ◽  
Reduce Emissions

Human existence is dependent on the consumption of electricity and of thermal energy. One of the environmental problems is represented by the particulate matter with the diameter of less than 2.5 mm derived from combustion of coal. In order to find solutions to reduce emissions at source, the particle size distribution of the coal bottom ash after removing it from the steam boiler of the large combustion plant from Romag Halanga in Drobeta Turnu – Severin area was determined. Dry particle size distribution shows that the major fraction is one that has a particle size of 125 μm. Particle size distribution in the smallest size fraction was performed with laser diffraction particle size analyzer Brookhaven 90 Plus Nanoparticle Size Analyzer. Particle size distribution shows that in the composition of the coal bottom ash were found particles with nanometric dimensions.

Particle Size of Rubber Globules in Hevea Latex

1952 ◽  
Vol 25 (2) ◽  
pp. 315-320
Author(s):  
M. van den Tempel
Keyword(s):  
Particle Size ◽  
Frequency Distribution ◽  
Distribution Curve ◽  
Average Particle Size ◽  
Average Particle ◽  
Size Frequency Distribution ◽  
Size Frequency ◽  
Asymmetrical Shape ◽  
Frequency Distribution Curve ◽  
Number Of Particles

Abstract 1. The use of visible light in determining the average particle size or the particle-size distribution in Hevea latex renders the results meaningless, as only about 40 per cent of the particles have a diameter of more than 0.2 µ. 2. In considering the size-frequency distribution curve as determined by Lucas, it could be assumed that, actually, the number of particles having a diameter of less than 0.12 µ might be very much larger than has been indicated by him. The agreement with the determination of the number of particles by van Gils, however, may be taken as evidence in favor of the correctness of the curve as given by Lucas. 3. An expression has been given which describes the size-frequency distribution curve, as found by Lucas, with a high degree of accuracy. It is necessary to assume that no particles larger than 5.2 µ are present in the latex. 4. Attention is directed to the considerable difference existing between the various average diameters, caused by the strongly asymmetrical shape of the size-frequency distribution curve. This work forms part of the program of fundamental research on latex problems undertaken by the Research Department of the Rubber-Stichting, Delft, under the management of H. C. J. de Decker.

The Feasibility Study of Laser Particle Size Analyzer for Thick Pastes

2013 ◽  
Vol 372 ◽  
pp. 428-432
Author(s):  
Shuang Yu Zhang ◽  
Fu Yan Lv ◽  
Zheng Meng Xia ◽  
Na Li ◽  
Miao Wu
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Traditional Method ◽  
Particle Sizes ◽  
Laser Particle Size Analyzer ◽  
Upper Limit ◽  
Particle Size Analyzer ◽  
Coal Slime ◽  
Physical And Chemical

The particle size distribution determines the physical and chemical characteristics of the particle swarm, and then affects rheological properties and transportation resistance characteristics of the thick pastes . Therefore we should find a method to appropriately describe the particle size distribution of thick pastes. Take coal slime to represent, we contrast laser particle size analyzer test with traditional sieving test to find whether the laser particle size analyzer applies to thick pastes or not. The test shows that the laser particle size analyzer which is suitable for the thick pastes to measure their particle sizes. Although its results cant match with the traditional method perfectly, the upper limit particle size can be used as comparison parameter of both methods. In future, the particle size distribution can be directly used, and there is no need to translate it into the sieving particle size distribution.

Testing and Evaluation on Fractal Characteristic of Cementing Materials Powder

2011 ◽  
Vol 374-377 ◽  
pp. 1848-1853
Author(s):  
Ning Chen ◽  
Ming Tang ◽  
Jing Qi Li ◽  
Hong Liang Liu
Keyword(s):  
Particle Size ◽  
Fractal Dimension ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Powder Materials ◽  
Fractal Characteristic ◽  
Laser Particle Size Analyzer ◽  
Cement Powder ◽  
Transmission Electron ◽  
Particle Size Analyzer

The cement powder materials are evaluated by fractal theory. Fractal characteristic parameters are analysed and evaluated by the method of laser particle size analyzer, microscope, transmission electron microscope. In this paper, cement powder materials has good self-similarity. Fractal dimension of grading is tested and evaluated by laser particle size analyzer, fractal dimension of cluster is tested by microscope, fractal characteristic of particle distribution is tested by transmission electron microscope. Compared with traditional weight of screen residue and specific surface area, those methods are more careful. Fineness fractal parameters and activity of ultra fine fly ash and pulverized slag have good linear dependence relation that is evaluated by fractal dimensions. Fractal characteristics provide an important basis to further explore the inherent relation of cement powder materials and concrete material density effect.

Study of the microstructure and particles of vanadium (III) oxide, vanadium (V) oxide and lithium aluminate powders

2020 ◽  
Vol 86 (1) ◽  
pp. 32-37
Author(s):  
Valeria A. Brodskaya ◽  
Oksana A. Molkova ◽  
Kira B. Zhogova ◽  
Inga V. Astakhova
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Vanadium Oxide ◽  
Size Distribution ◽  
Microstructural Analysis ◽  
Coherent Scattering ◽  
Powder Materials ◽  
Lithium Aluminate ◽  
Range Limit ◽  
Oxide Particles

Powder materials are widely used in the manufacture of electrochemical elements of thermal chemical sources of current. Electrochemical behavior of the powders depends on the shape and size of their particles. The results of the study of the microstructure and particles of the powders of vanadium (III), (V) oxides and lithium aluminate obtained by transmission electron and atomic force microscopy, X-ray diffraction and gas adsorption analyses are presented. It is found that the sizes of vanadium (III) and vanadium (V) oxide particles range within 70 – 600 and 40 – 350 nm, respectively. The size of the coherent-scattering regions of the vanadium oxide particles lies in the lower range limit which can be attributed to small size of the structural elements (crystallites). An average volumetric-surface diameter calculated on the basis of the surface specific area is close to the upper range limit which can be explained by the partial agglomeration of the powder particles. Unlike the vanadium oxide particles, the range of the particle size distribution of the lithium aluminate powder is narrower — 50 – 110 nm. The values of crystallite sizes are close to the maximum of the particle size distribution. Microstructural analysis showed that the particles in the samples of vanadium oxides have a rounded (V2O3) or elongated (V2O5) shape; whereas the particles of lithium aluminate powder exhibit lamellar structure. At the same time, for different batches of the same material, the particle size distribution is similar, which indicates the reproducibility of the technologies for their manufacture. The data obtained can be used to control the constancy of the particle size distribution of powder materials.

Effects of Multiple Impacts and Size Distribution of Particles on Erosion Predictions Using CFD

2007 ◽  
Author(s):  
Yongli Zhang ◽  
Brenton S. McLaury ◽  
Siamack A. Shirzai
Keyword(s):  
Experimental Data ◽  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Target Material ◽  
Average Particle ◽  
Multiple Impacts ◽  
Cfd Simulations ◽  
Erosion Damage ◽  
Wide Range

Erosion equations are usually obtained from experiments by impacting solid particles entrained in a gas or liquid on a target material. The erosion equations are utilized in CFD (Computational Fluid Dynamics) models to predict erosion damage caused by solid particle impingements. Many erosion equations are provided in terms of an erosion ratio. By definition, the erosion ratio is the mass loss of target material divided by the mass of impacting particles. The mass of impacting particles is the summation of (particle mass × number of impacts) of each particle. In erosion experiments conducted to determine erosion equations, some particles may impact the target wall many times and some other particles may not impact the target at all. Therefore, the experimental data may not reflect the actual erosion ratio because the mass of the sand that is used to run the experiments is assumed to be the mass of the impacting particles. CFD and particle trajectory simulations are applied in the present work to study effects of multiple impacts on developing erosion ratio equations. The erosion equation as well as the CFD-based erosion modeling procedure is validated against a variety of experimental data. The results show that the effect of multiple impacts is negligible in air cases. In water cases, however, this effect needs to be accounted for especially for small particles. This makes it impractical to develop erosion ratio equations from experimental data obtained for tests with sand in water or dense gases. Many factors affecting erosion damage are accounted for in various erosion equations. In addition to some well-studied parameters such as particle impacting speed and impacting angle, particle size also plays a significant role in the erosion process. An average particle size is usually used in analyzing experimental data or estimating erosion damage cases of practical interest. In petroleum production applications, however, the size of sand particles that are entrained in produced fluids can vary over a fairly broad range. CFD simulations are also performed to study the effect of particle size distribution. In CFD simulations, particle sizes are normally distributed with the mean equaling the average size of interest and the standard deviation varying over a wide range. Based on CFD simulations, an equation is developed and can be applied to account for the effect of the particle size distribution on erosion prediction for gases and liquids.

Tape Casting of BaTiO3

1984 ◽  
Vol 40 ◽  
Author(s):  
J. B. Blum ◽  
W. R. Cannon
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Glass Plate ◽  
Tape Casting ◽  
Phosphate Ester ◽  
Powder Particle Size ◽  
Drying Method ◽  
Ultrasonic Dispersion ◽  
The Past

AbstractFor the past two years we have been investigating the tape casting of BaTiO3 Specifically we have been interested in developing a useful tape casting formulation and procedure and in studying the effects of powder particle size distribution and dispersion processes on the forming of BaTiO3 tapes.The formulation we have developed is non-aqueous. An MEKethanol mixture is the solvent and an acrylic binder is used. Two dispersants are being used, a phosphate ester and Menhaden fish oil. Ultrasonic dispersion was found to be effective in breaking up weak powder agglomerates. We have found it important to add the dispersant before adding other organic components to obtain the best dispersion and strongest tapes. The drying method is also important to tape strength. The strongest tapes resulted when the tape was removed from the glass plate soon after casting. We have also demonstrated that for forming purposes a wide particle size distribution is preferred.

Modeling the Production Technology of Fully-Pressed Bi-Metal Powder Materials and Products

2021 ◽  
Vol 316 ◽  
pp. 570-575
Author(s):  
Badrudin G. Gasanov ◽  
Abakar B. Gasanov ◽  
Artem A. Aganov
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Bulk Density ◽  
Size Distribution ◽  
Metal Powder ◽  
Production Technology ◽  
Powder Mixture ◽  
Geometric Parameters ◽  
Powder Materials ◽  
Loading Devices

The features of calculating the thickness of the layers of bimetallic powder products without holes and the type of bushings are shown. The effect of the particle size distribution of the powders, the kinematic and geometric parameters of the loading devices and molds on the mechanism of the expiration of the powder mixture and on the thickness of the layers of the molded product is studied. A technique has been developed for determining the dimensions of the feeder cassette and tooling, depending on the overall dimensions and thicknesses of the working layers, in the production of whole-pressed bimetallic products on press machines with a vertical arrangement of layers. It was found that the thickness of each layer of bimetallic products depends on the geometric parameters of the feeder cassette and tooling, bulk density, particle size distribution and other characteristics of the powders, as well as on the speed of lowering the lower punch ν1 .

scholarly journals Particle Size Distribution of E-Cigarette Aerosols and the Relationship to Cambridge Filter Pad Collection Efficiency

2015 ◽  
Vol 26 (4) ◽  
Author(s):  
Steven L. Alderman ◽  
Chen Song ◽  
Serban C. Moldoveanu ◽  
Stephen K. Cole
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Propylene Glycol ◽  
Collection Efficiency ◽  
Transmission Measurement ◽  
Average Particle ◽  
Electrical Mobility ◽  
Total Particulate Matter

AbstractThe relatively volatile nature of the particulate matter fraction of e-cigarette aerosols presents an experimental challenge with regard to particle size distribution measure-ments. This is particularly true for instruments requiring a high degree of aerosol dilution. This was illustrated in a previous study, where average particle diameters in the 10-50 nm range were determined by a high-dilution, electrical mobility method. Total particulate matter (TPM) masses calculated based on those diameters were orders of magnitude smaller than gravimetrically determined TPM. This discrepancy was believed to result from almost complete particle evaporation at the dilution levels of the electrical mobility analysis. The same study described a spectral transmission measurement of e-cigarette particle size in an undiluted state, and reported particles from 210-380 nm count median diameter. Observed particle number concentrations were in the 10Described here is a study in which e-cigarette aerosols were collected on Cambridge filters with adsorbent traps placed downstream in an effort to capture any material passing through the filter. Amounts of glycerin, propylene glycol, nicotine, and water were quantified on the filter and downstream trap. Glycerin, propylene glycol, and nicotine were effciently captured (> 98%) by the upstream Cambridge filter, and a correlation was observed between filtration efficiency and the partial vapor pressure of each component. The present analysis was largely inconclusive with regard to filter efficiency and particle-vapor partitioning of water. [Beitr. Tabakforsch. Int. 26 (2014) 183-190]

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