Automation of size fractionation to extract clays and silts

Clay Minerals ◽  
2011 ◽  
Vol 46 (3) ◽  
pp. 515-523 ◽  
Author(s):  
Youjun Deng ◽  
M. G. Tenorio Arvide

AbstractThe objective of this study was to build an automated size fractionator to process up to 16 samples at one time. Most parts used in the apparatus are inexpensive items, available from lawn irrigation, household appliance and aquatic pet supply stores. The device can be used to extract different silt and clay fractions by changing sedimentation time. A bentonite, a kaolin and an ironoxide-rich Oxisol were fractionated by this instrument to sequentially extract particles that have sizes equivalent to <2 µm, <5 µm, <10 µm and <20 µm quartz spheres. A laser diffraction particle size analyser revealed size differences in the different fractions and also showed that the silt fractions contained particles having slightly larger sizes than the assumed diameters of spherical quartz. Scanning electron microscope examination suggested that the greater particle size was mainly due to the non-spherical shapes of the particles and a reduced bulk density of the porous aggregates.

2021 ◽  
Vol 02 (01) ◽  
Author(s):  
Siti Khadijah Hubadillah ◽  
◽  
Norsiah Hami ◽  
Nurul Azita Salleh ◽  
Mohd Riduan Jamalludin ◽  
...  

The purpose of this work is to study the effect of kaolin particle size for the preparation of low cost ceramic membrane suspension and ceramic membrane structure. Kaolin particle size is categorized into two categories; i) ≤ 1µm and ii) ≥ 1 µm. The suspension is prepared via stirring technique under 1000 rpm at 60°C. The particle size of kaolin is characterized using field emission scanning electron microscope (FESEM) and the prepared suspension is characterized in term of its viscosity. Results indicate that the particle size gave significant effect to the viscosity of ceramic membrane suspension. Preliminary data showed that kaolin with particle size ≤ 1µm resulted ceramic membrane with dense structure.


2019 ◽  
Vol 25 (05) ◽  
pp. 1183-1194
Author(s):  
Mandy C. Nevins ◽  
Richard K. Hailstone ◽  
Eric Lifshin

AbstractPoint spread function (PSF) deconvolution is an attractive software-based technique for resolution improvement in the scanning electron microscope (SEM) because it can restore information which has been blurred by challenging operating conditions. In Part 1, we studied a modern PSF determination method for SEM and explored how various parameters affected the method's ability to accurately estimate the PSF. In Part 2, we extend this exploration to PSF deconvolution for image restoration. The parameters include reference particle size, PSF smoothing (K), background correction, and restoration denoising (λ). Image quality was assessed by visual inspection and Fourier analysis. Overall, PSF deconvolution improved image quality. Low λ enhanced image sharpness at the cost of noise, while high λ created smoother restorations with less detail. λ should be chosen to balance feature preservation and denoising based on the application. Reference particle size within ±0.9 nm and K within a reasonable range had little effect on restoration quality. Restorations using background-corrected PSFs had superior quality compared with using no background correction, but if the correction was too high, the PSF was cut off causing blurrier restorations. Future efforts to automatically determine parameters would remove user guesswork, improve this method's consistency, and maximize interpretability of outputs.


2016 ◽  
Vol 90 (4) ◽  
pp. 741-762 ◽  
Author(s):  
Brian L. Hoffman ◽  
Scott A. Hageman ◽  
Gregory D. Claycomb

AbstractAlthough Ptychodus teeth are well known in Late Cretaceous marine deposits in North America and Europe and a few specimens with jaw elements have been discovered, the taxonomic position of the shark genus Ptychodus is enigmatic due to the lack of preservation of diagnostic material other than teeth. These sharks possessed a pavement dentition suited to a diet of hard-shelled macroinvertebrates (durophagy), leading several studies to variously describe Ptychodus as a batoid, a hybodont shark, or a selachimorph. Members of the Selachimorpha share one dental synapomorphy, a triple-layered enameloid (TLE) consisting of an outer shiny-layered enameloid (SLE) of randomly oriented hydroxyapatite crystallites, a middle layer of parallel-bundled enameloid (PBE), and an inner layer of tangled-bundled enameloid (TBE). Batoids and hybodonts both have teeth with single crystallite enameloid (SCE). We examined teeth from Ptychodus collected from the Lincoln Limestone of the Greenhorn Formation of Barton County, Kansas, and compared their enameloid ultrastructure with that of a Carboniferous hybodontiform and the Cretaceous lamniform shark Squalicorax curvatus Williston, 1900. Scanning electron microscopic examination of Ptychodus shows that crystallite bundling in the form of a TLE is evident in these teeth. The PBE is most apparent at transverse enameloid ridges of Ptychodus teeth. Columns of dentine penetrate into the tooth enameloid, and the crystallites near the dentine are randomly oriented. These observations bolster the argument that Ptychodus is a genus of highly specialized selachimorph shark, rather than a hybodont or batoid.


2020 ◽  
Vol 866 ◽  
pp. 115-124
Author(s):  
Zhan Kui Wang ◽  
Ming Hua Pang ◽  
Jian Xiu Su ◽  
Jian Guo Yao

In this paper, a series of chemical mechanical polishing (CMP) experiments for magnesia alumina (Mg-Al) spinel were carried out with different abrasives, and the materials removal rate (MRR) and surface quality was evaluated to explore their different effects. The scanning electron microscope (SEM) and laser particle size analyzer were also employed to test the micro-shape and size distribution of abrasives. Then, the mechanism of different effects with different abrasives was analyzed in CMP for Mg-Al spinel. Those experimental results suggest that different subjecting pressure ratios of abrasives to polishing pad with different abrasive are the key factors leading to difference polishing performances in CMP.


2012 ◽  
Vol 463-464 ◽  
pp. 760-763
Author(s):  
Zhen Zhao Pei ◽  
Hong Bin Xu ◽  
Yi Zhang

Nanoparticles of Cr2O3 were successfully obtained via hydrothermal reduction of CH3OH. The oxidant and chromium source was CrO3. The process needs no stirrer or surfactant and the CrO3 concentration was 0.83mol/L. The obtained products were loosely agglomerated Cr2O3 nanoparticles with the average size of 29 to 79 nm. Influences of reactant ratios and calcination temperatures on the specific surface area and average particle size were discussed. And the morphology of nanoparticles was investigated by use of field-emission scanning electron microscope.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Qiuxiang Zhang ◽  
Xinhua Liu ◽  
Yankun Ren ◽  
Lifeng Wang ◽  
Yuan Hu

Aiming to study the effect of particle size on the wear property of magnetorheological fluid (MRF), experiment materials, preparation process, and test methods are elaborated, and three different MRF samples consisting of particles of different size are prepared. Test experiments are carried out and the effect of particle size on the wear property of MRF is discussed. Moreover, the microstructures of particles extracted from MRF obtained before and after the wear experiments are observed by scanning electron microscope (SEM). Experimental results show that the particle size has a significant effect on wear property of MRF. Furthermore, the MRF with particles of 1.5–2.8 μm diameter on average is good for the requirement of engineering applications.


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