scholarly journals The Significance of Size Screening on the Pretreatment of Low Grade Bauxite: A Case Study of Block E70 / 3160 in Darling Range of Australia

2022 ◽  
Vol 2152 (1) ◽  
pp. 012062
Author(s):  
Zhurui Shao ◽  
Yunhan Liang ◽  
Pan Zhang ◽  
Zhiqiang Chen ◽  
Zhenguo Jiang ◽  
...  
Keyword(s):  
Particle Size ◽  
Screening Method ◽  
Optimal Combination ◽  
Low Grade ◽  
Particle Sizes ◽  
X Ray ◽  
Two Samples ◽  
Silica Ratio ◽  
Reactive Silica

Abstract In this paper, the size screening method and X-ray fluorescent spectroscopy were used to analyze low-grade bauxite samples from Darling Range, Australia. The results showed that the Av Al / Re Si(available alumina to reactive silica ratio) of samples JDB225 and JDB364 increased by 34.5% (8.7% to 11.7%) and 11.2% (8.9% to 9.9%); the available aluminum increased by 11.2% (27.8% to 30.9%) and 4.9% (30.9% to 32.4%) respectively. In screening, the optimum particle sizes of the two samples were 4 mm and 2.8 mm respectively. The results show that the best screening particle size can be determined by the size screening method, which can achieve the optimal combination of available aluminum grade, Av Al / Re Si and mass recovery rate, so as to significantly improve the grade and Av Al / Re Si of low-grade bauxite.

Use of Ceramic Waste for the Manufacture of Sintered Parts

2020 ◽  
Vol 1012 ◽  
pp. 233-238
Author(s):  
Vanessa Moura de Souza ◽  
Vinícius Martins ◽  
Rejane Maria Candiota Tubino
Keyword(s):  
Particle Size ◽  
Selection Process ◽  
Compaction Pressure ◽  
Raw Material ◽  
Powder Technology ◽  
Particle Sizes ◽  
Compression Pressure ◽  
X Ray ◽  
Ceramic Waste ◽  
Quality Process

This paper evaluated the use of the pitcher, a ceramic waste obtained through the quality process of a sanitary ware industry, in the development of a material for usage in the manufacture of sintered parts. The pitcher was obtained through powder technology and is composed, according to the chemical analysis obtained by X-ray fluorescence spectrometry, of clayey minerals (clay and kaolin), quartz, and feldspar, which may include ceramic rocks such as granite, pegmatite and phyllite; that is, it has proved to be a potential raw material due to the minerals that can still be reused. The pitcher passed through a granulometry-based selection process, sieving about 20kg using the following sieve sequence: 18 MESH, 25 MESH, 30 MESH, 120 MESH and 400 MESH; with around 70% of the residue being retained in the sieves of 120 and 400 MESH, which were selected to be used in the evaluation. The samples were compacted in a manual press with different pressures, between 300 and 1000 kgf, and after were sintered at a temperature of 1100oC in a resistive furnace. To characterize the material, the apparent and green density, as well as the compressibility curve, were determined to identify the best compression pressure. The microstructure of the test specimen and the pitcher homogeneity were evaluated using Scanning Electron Microscopy (SEM). Both particle sizes presented the typical compressibility curve, in which the density increases with increasing compaction pressure, while the curve slope decreases with increasing pressure. The density increase with the increasing compaction pressure indicates a good densification for the temperatures, independent of the sample granulometry. The sintering porosity decreased proportionally to the particle size in the sintered samples. The analysis showed that the particle size of 400 MESH sintered at 1100oC obtained more porous surfaces, thus indicating a promising future for the manufacture of parts using powder technology, especially for the development of filters.

scholarly journals Theoretical and Experimental Evaluation of Particle size Effect of Iron , Cobalt ,and Nickel Powders Suspended in Al Dura oil on XRF Intensities

2007 ◽  
Vol 4 (3) ◽  
pp. 475-481
Author(s):  
Baghdad Science Journal
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Laser System ◽  
Particle Size Effect ◽  
Particle Sizes ◽  
Iron Cobalt ◽  
X Ray ◽  
Nickel Powders ◽  
Good Agreement ◽  
Cobalt And Nickel

Iron , Cobalt , and Nickel powders with different particle sizes were subjected to sieving and He-Ne laser system to determine the particle size . 1wt% from each powders was blended carefully with 99wt% from Iraqi oil . Microscopic examination were carried for all samples to reveal the particle size distribution . A Siemens type SRS sequential wavelength dispersive(WDS) X-ray spectrometer was used to analyze all samples , and the XRF intensity were determined experimentally and theoretically for all suspended samples , Good agreement between theoretical and experimental results were found .

Oxygen-Enriched Combustion Characteristics of Lignite: A Case Study of the Pingzhuang Lignite from Inner Mongolia, China

2012 ◽  
Vol 550-553 ◽  
pp. 2868-2872
Author(s):  
Xiang Yun Chen ◽  
Yong Feng Zhang ◽  
Qian Cheng Zhang ◽  
Jie Bai ◽  
Fei Wu
Keyword(s):  
Particle Size ◽  
Oxygen Concentration ◽  
Volume Fraction ◽  
Particle Sizes ◽  
Temperature Zone ◽  
Thermogravimetric Method ◽  
Combustion Experiment ◽  
Lower Temperature ◽  
Lower Temperature Zone

Combustion curves of lignite samples from China in four different particle sizes and Oxygen-enriched condition were analyzed using non-isothermal thermogravimetric method. The lignite samples separated into -150+100 μm, -100+75 μm, -75+50 μm, and -50μm sizes. Combustion profiles shift to lower temperature zone as particle size decrease. Combustion profiles have little difference when the particle size below 100 μm in oxygen atmosphere; Oxygen-enriched combustion experiment were carried out in O2/N2 mixture atmospheres with the volume fraction of oxygen was 21%, 30%, 40%, 50%, 60% and 70%, respectively. As oxygen concentration increase profiles shift to lower temperature zone. and gets the proper range of oxygen concentration is about 50%.

scholarly journals Effects of Size and Dispersity of Microcrystalline Celluloses on Size, Structure and Stability of Nanocrystalline Celluloses Extracted by Acid Hydrolysis

Nano LIFE ◽  
2014 ◽  
Vol 04 (04) ◽  
pp. 1441014 ◽  
Author(s):  
Qi Liu ◽  
Weiping Hao ◽  
Yongguang Yang ◽  
Aurore Richel ◽  
Canbin Ouyang ◽  
...  
Keyword(s):  
Particle Size ◽  
Acid Hydrolysis ◽  
Size Structure ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Sonication Treatment

Nanocrystalline celluloses (NCCs) were separated from four commercial microcrystalline celluloses (MCCs) by an acid hydrolysis–sonication treatment. Transmission electron microscopy (TEM), atomic force microscopy (AFM), Fourier transform infrared (FTIR) spectrum, X-ray diffraction (XRD) and thermogravimetric analysis (TGA) were conducted to investigate the NCCs. MCCs with different morphologies and particle sizes showed different aggregation degrees. The aggregation of MCCs followed the order MCC1 > MCC3 > MCC2 > MCC4, which is the same order of the heights of the resulting NCCs. The best uniformity and thermal stability were characterized for NCC3, which was produced by MCC3 with smallest original particle size and good dispersity among the four MCCs. This result suggests that both the original particle size and dispersity of MCCs had significant effects on separated NCCs.

scholarly journals Parametric Study of Matisaa Gray Rock as a Potential Clinker Material

2020 ◽  
pp. 22-29
Author(s):  
Mwendwa Geoffrey ◽  
Motochi Isaac ◽  
Otieno Fredrick
Keyword(s):  
Particle Size ◽  
Size Composition ◽  
Particle Size Analysis ◽  
Raw Material ◽  
Size Analysis ◽  
Particle Sizes ◽  
X Ray ◽  
Saturation Factor ◽  
Clinker Production

This study aimed at evaluating Matisaa gray rock (MGR) for clinker production. MGR is naturally abundant in Matisaa, a rural area in Mwingi West District, Kitui county, Kenya. It is locally used as a gabion filler and other concrete structures with desirable physico-mechanical properties. This research employed a controlled experimental design to determine the clinker qualification of MGR. This was based on particle size analysis and raw meal moduli. The standard sieve tests and a Blaine meter were used in the determination of particle size while the raw meal moduli were determined from the respective cement oxides in MGR, which were determined using wavelength dispersive X-ray fluorescence (WDXRF) spectrometer. It was observed that 69.65% of the particle size composition of MGR was less than 90 . Out of this composition, 71.60% of the particle sizes were less than 45 , contributing to a specific surface area of 292.5 . The hydraulic modulus (2.05 – 2.61) and lime saturation factor (0.87 – 0.98) are quite desirable though the silica and alumina ratios are higher than the standard range due to the low proportions of  and  content. The sulfatisation modulus is also undesirable due to the high content of . Thus, without beneficiation, Matisaa gray rock would lead to the production of low-quality clinker. However, the general parametric comparison of Matisaa gray rock with Konza shows that it has the potential for utilization as a clinker raw material.

Conquer by cryo-EM without physically dividing

2021 ◽  
Author(s):  
Gabriel C. Lander ◽  
Robert M. Glaeser
Keyword(s):  
Particle Size ◽  
High Resolution ◽  
Single Particle ◽  
Region Of Interest ◽  
Divide And Conquer ◽  
Particle Sizes ◽  
X Ray ◽  
X Ray Crystallography ◽  
Substantial Progress ◽  
Made In

This mini-review provides an update regarding the substantial progress that has been made in using single-particle cryo-EM to obtain high-resolution structures for proteins and other macromolecules whose particle sizes are smaller than 100 kDa. We point out that establishing the limits of what can be accomplished, both in terms of particle size and attainable resolution, serves as a guide for what might be expected when attempting to improve the resolution of small flexible portions of a larger structure using focused refinement approaches. These approaches, which involve computationally ignoring all but a specific, targeted region of interest on the macromolecules, is known as ‘masking and refining,' and it thus is the computational equivalent of the ‘divide and conquer' approach that has been used so successfully in X-ray crystallography. The benefit of masked refinement, however, is that one is able to determine structures in their native architectural context, without physically separating them from the biological connections that they require for their function. This mini-review also compares where experimental achievements currently stand relative to various theoretical estimates for the smallest particle size that can be successfully reconstructed to high resolution. Since it is clear that a substantial gap still remains between the two, we briefly recap the areas in which further improvement seems possible, both in equipment and in methods.

Sintering Behaviors of Pt Nanopowders with Different Particle Sizes: A Real-Time Synchrotron X-ray Scattering Study

2021 ◽  
Vol 16 (5) ◽  
pp. 849-853
Author(s):  
Jang-Hyeong Lee ◽  
Tae-Sik Cho
Keyword(s):  
Particle Size ◽  
Solid State ◽  
Grain Boundary ◽  
Grain Growth ◽  
Boundary Diffusion ◽  
Domain Size ◽  
Particle Sizes ◽  
X Ray ◽  
X Ray Scattering ◽  
Solid State Sintering

We have studied the solid state sintering behaviors of platinum (Pt) nanopowders with different particle sizes using real-time synchrotron X-ray scattering in air. Pt powders with large particle size of 101 nm at room temperature (RT) showed a defect-free crystal domain size of 10 nm. Most of these powders exhibited multiple grains inside the particle. Solid state sintering of the powders mainly occurred through surface diffusion of Pt atoms near 145 °C, grain boundary diffusion from 150 to 400 °C, and then grain growth above 550 °C. Meanwhile, Pt nanopowders with small particle size of 18 nm at RT showed a crystal domain size of 8 nm. Most of these powders exhibited a single grain inside the particle. Solid state sintering of the nanopowders mainly occurred through surface diffusion of Pt atoms near 151 °C and then grain growth above 400 °C. Grain boundary diffusion does not happen because grain boundary hardly exists.

Investigation of Mg2Si formation from Si and Mg by using spark plasma sintering synthesis

2015 ◽  
Vol 1735 ◽  
Author(s):  
Kota Sunohara ◽  
Koya Arai ◽  
Tomoyuki Nakamura ◽  
Kenjiro Fujimoto ◽  
Yuki Yamaguchi ◽  
...  
Keyword(s):  
Particle Size ◽  
Spark Plasma Sintering ◽  
Inert Gas ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plasma Sintering ◽  
Spark Plasma

AbstractIn this study, we fabricated Mg2Si from metal Mg and Si with different particle sizes (425 - 300, 300 - 180, and 75 μm or less) using spark plasma sintering (SPS) equipment. Additionally, the Mg2Si formation was investigated. A sieved Si powder was mixed with metal Mg powder in an inert gas (Ar) atmosphere. The mixture was placed in a graphite die while still in an Ar atmosphere and subjected to SPS at 923 K and 1113 K. The obtained sintering bodies were Mg2Si particles with a size of about 5 μm. Then, the sintered bodies were evaluated by X-ray diffraction (XRD). As a result, it was confirmed that generation of Mg2Si increased with decreasing Si particle size.

Application of X-Ray Fluorescence Analysis to Process Control

1961 ◽  
Vol 5 ◽  
pp. 486-499 ◽  
Author(s):  
F. Bernstein
Keyword(s):  
Particle Size ◽  
Process Control ◽  
Sampling Technique ◽  
Fluorescence Analysis ◽  
Particle Sizes ◽  
X Ray ◽  
Direct Sampling ◽  
Precision And Accuracy ◽  
Relationship Of ◽  
The Relationship

AbstractThe application of X-ray fluorescence-analysis methods to process control is discussed. Various methods of sample preparation are reviewed and compared. The use of the direct sampling technique is discussed and consideration is given to the effects of particle size on precision and accuracy of analytical results. The mechanism of these effects if presented, and some general principles concerning the relationship of fluorescent intensities and particle sizes of pure materials and mixtures are derived. Examples of particle-size effects in cement and mining applications are illustrated.

Behaviours of Zinc and Lead in Blast Furnace of Baotou Iron and Steel Group Co.

2011 ◽  
Vol 194-196 ◽  
pp. 306-309 ◽  
Author(s):  
Fang Zhang ◽  
Sheng Li An ◽  
Guo Ping Luo ◽  
Shi Zhong Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Particle Size ◽  
Blast Furnace ◽  
Particle Sizes ◽  
Iron And Steel ◽  
X Ray ◽  
Lead And Zinc ◽  
Particle Size Analyzer ◽  
Scanning Electron

The balance calculation of zinc and lead of No.1 BF of Baotou Iron and Steel Group Co. was performed in this research. The particle sizes of BF dusts were measured by LS230 laser particle size analyzer. The micrology of sinter and dusts were investigated with scanning electron microscopy (SEM, Hitachi S-3000) coupled with an energy-dispersive X-ray analysis (EDX). The results show that the general burdens of zinc and lead in No. 1 mainly came from sinter and pellet. The burdens of zinc and lead in No.1 BF were 645.45g/t and 370.33 g/t respectively, which were too much to need take some measures. Among the gas ash, the particle size of baghouse dust was minimal, but the contents of lead and zinc were highest. So the BF baghouse dust isn’t appropriate to recover as the sintering materials. The speciation of lead is PbO, PbCl3 and metallic Pb, but zinc never presents as metal in BF dusts.

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