Large Particle Size Distribution in Five U.S. Cities and the Effect on a New Ambient Participate Matter Standard (PM10)

Water and sand inrush is one of the most serious threats in some shallow coal mines in China. In order to understand the process of sand inrush, experiments were performed to obtain the criterion for sand inrush. First, seepage tests were carried out to study the hydraulic properties of granular sandstone. The results indicate that seepage velocity has a linear relation with the porosity and particle-size distribution parameter. Then, sand inrush tests were conducted to investigate the critical conditions for sand inrush occurrence. It is determined that the sand inrush zone can be clearly distinguished based on the values of porosity and particle-size distribution parameter. Additionally, sand inrush tended to happen in the conditions of high porosity, high seepage velocity, and large particle-size distribution parameter. Further, general principles for preventing the water and sand inrush were proposed, such as reducing the porosity, improving the pore structure, and decreasing the seepage velocity. The proposed principles have been successfully used in situ to control the water and sand inrush.

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Microcapsule Particle Size and Size Distribution and its Influencing Factors

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.746.118 ◽

2013 ◽

Vol 746 ◽

pp. 118-122 ◽

Cited By ~ 2

Author(s):

Zhao Hui Zhen ◽

Zheng Shun Wang

Keyword(s):

Particle Size ◽

Size Distribution ◽

Influencing Factors ◽

Large Particle ◽

Ph Value ◽

Low Ph ◽

Formaldehyde Resin ◽

Melamine Formaldehyde ◽

Large Particle Size ◽

Rough Surface Morphology

The paper studied the microcapsule particle size, size distribution and its influencing factors with melamine formaldehyde resin (MF-resin) as wall and CVL as core. The results indicated that the microcapsules mean particle size decreased, size distribution became narrow with the increase of emulsifying time and shear rate. Low pH value would make the microcapsules have rough surface morphology and large particle size.

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Development and Validation of an Online Analyzer for Particle Size Distribution in Conveyor Belts

Minerals ◽

10.3390/min11060581 ◽

2021 ◽

Vol 11 (6) ◽

pp. 581

Author(s):

Claudio Leiva ◽

Claudio Acuña ◽

Diego Castillo

Keyword(s):

Image Processing ◽

Particle Size ◽

Energy Consumption ◽

Particle Size Distribution ◽

Size Distribution ◽

Large Particle ◽

Equivalent Diameter ◽

Online Measurement ◽

Particle Detection ◽

Detection Algorithms

Online measurement of particle size distribution in the crushing process is critical to reduce particle obstruction and to reduce energy consumption. Nevertheless, commercial systems to determine size distribution do not accurately identify large particles (20–250 mm), leading to particle obstruction, increasing energy consumption, and reducing equipment availability. To solve this problem, an online sensor prototype was designed, implemented, and validated in a copper ore plant. The sensor is based on 2D images and specific detection algorithms. The system consists of a camera (1024p) mounted on the conveyor belt and image processing software, which improves the detection of large particle edges. The algorithms determine the geometry of each particle, from a sequence of digital photographs. For the development of the software, noise reduction algorithms were evaluated and selected, and a routine was designed to incorporate morphological mathematics (erosion, dilation, opening, lock) and segmentation algorithms (Roberts, Prewitt, Sobel, Laplacian–Gaussian, Canny, watershed, geodesic transform). The software was implemented (in MatLab Image Processing Toolbox) based on the 3D equivalent diameter (using major and minor axes, assuming an oblate spheroid). The size distribution adjusted to the Rosin Rammler function in the major axis. To test the sensor capabilities, laboratory images were used, where the results show a precision of 5% in Rosin Rambler model fitting. To validate the large particle detection algorithms, a pilot test was implemented in a large mining company in Chile. The accuracy of large particle detection was 60% to 67% depending on the crushing stage. In conclusion, it is shown that the prototype and software allow online measurement of large particle sizes, which provides useful information for screening equipment maintenance and control of crushers’ open size setting, reducing the obstruction risk and increasing operational availability.

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Hevea Latex of Large Particle Size

Rubber Chemistry and Technology ◽

10.5254/1.3539524 ◽

1940 ◽

Vol 13 (2) ◽

pp. 415-421

Author(s):

J. McGavack

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Aqueous Ammonia ◽

Water Soluble ◽

Distribution Data ◽

Particle Sizes ◽

Volume Changes ◽

Large Particle Size ◽

Complete Work

Abstract The purpose of this paper is to report, primarily, the particle size distribution of modified Hevea latices. In addition, the purpose is to show that the amount of nitrogen absorbed by the rubber particles in a latex thoroughly washed by aqueous ammonia depends on the surface exposed. Until the careful and complete work of Lucas (Ind. Eng. Chem. 30, 146 (1938)), there were no reliable particle size distribution data on a normal latex by which the distribution curves of modified latices could be compared. Now, as a result of his excellent technique for measuring all of the particles, even the very small ones, we are able to discuss clearly surface and volume changes when these smaller sized particles are removed. This work was so conducted as to eliminate particle sizes which could not be photographed with microscopical equipment in visible light. It was eventually carried out in such a way as to remove all water-soluble materials not adsorbed on or dissolved in the latex particles which were to be subsequently analyzed for nitrogen.

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Preparation of spherical large-particle MCM-41 with a broad particle-size distribution by a modified pseudomorphic transformation

Microporous and Mesoporous Materials ◽

10.1016/j.micromeso.2009.01.018 ◽

2009 ◽

Vol 121 (1-3) ◽

pp. 73-78 ◽

Cited By ~ 10

Author(s):

Xianbin Liu ◽

Hui Sun ◽

Yuan Chen ◽

Yanhui Yang ◽

Armando Borgna

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Large Particle ◽

Mcm 41

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Synthesis and Characterization Nanoparticles ZnAl1.94(Yb:Er)0.06O4 Functionalized with Chitosan

Materials Science Forum ◽

10.4028/www.scientific.net/msf.727-728.263 ◽

2012 ◽

Vol 727-728 ◽

pp. 263-268 ◽

Cited By ~ 2

Author(s):

Cristiane M. Furtado ◽

Pascally M.A. Guerra de Araújo ◽

Patrícia T.A. dos Santos ◽

Ana Cristina F. de M. Costa

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Large Particle ◽

Chitosan Nanoparticles ◽

Spherical Shape ◽

Secondary Phase ◽

Synthesis And Characterization ◽

Large Particle Size ◽

Before And After ◽

Large Clusters

This work aims to synthesize combustion reaction, functionalized with chitosan nanoparticles and characterize ZnAl1.94(Yb:Er)0.06O4, codoped with x = 0.06 mol in the proportion 5:1 of Yb:Er. Nanoparticles before and after functionalization were characterized by XRD, TGA/DTA, FTIR and SEM. The results show that before and after functionalization presented ZnAl2O4majority phase and Al2Yb4O as secondary phase. Multiple bands around 1100 cm-1and 1040 cm-1corresponding to the asymmetric stretching Si-O confirms the functionalization of nanoparticles. Nanoparticles presented before functionalization morphology heterogeneous, consisting of clusters of particles with near-spherical shape, large particle size distribution, consisting of large clusters with size around 3 µm and smaller clusters in the shape of plates with size in order of 0.5 µm. After functionalization, the morphology shows the formation of a film consisting of amorphous phase and crystalline phase. The mass loss for the nanoparticles before and after functionalization was 7.2 and 39%, respectively.

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Characteristics Research and Selective Leaching of Anode Slime with High Content of Copper and Stannum

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1010-1012.1594 ◽

2014 ◽

Vol 1010-1012 ◽

pp. 1594-1597 ◽

Cited By ~ 3

Author(s):

Wei Wang ◽

Zheng Xu ◽

Song Tao Huang ◽

Li Mei Yang ◽

Liu Lu Cai ◽

...

Keyword(s):

Particle Size ◽

Hydrochloric Acid ◽

Particle Size Distribution ◽

Copper Sulfide ◽

Large Particle ◽

Precious Metals ◽

Stannic Oxide ◽

Anode Slime ◽

Selective Leaching ◽

Large Particle Size

The anode slime comes from the process of scrap copper electrolysis which contains high content of copper, stannum and some other metals, such as lead, antimony and precious metals. The result of particle size distribution showed that copper exist in large particle-size parts more than in small ones, while most of stannum concentrate in small particle ones. XRD and MLA were employed to characterize the anode slime. Copper is occurrence in copper sulfide, while stannum is in stannic oxide. Selective leaching by using hydrochloric acid has been conducted based on initial analysis. 97.86% of antimony, 96.24% of stannum and 93.68% of lead were leached. 82.5% of copper remained in the residue. Copper can be separated with antimony, Stannum and lead effectively.

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