Preparation of Nano-Sized Wollastonite Using Calcium Silicate Residue of Potassium Feldspar after Extraction of Potassium and Alumina

2014 ◽  
Vol 633 ◽  
pp. 35-38 ◽  
Author(s):  
Jian Chen ◽  
Jing Yang ◽  
Hong Wen Ma

In this paper, wollastonite nanopowder were successfully synthesized by the surfactants modified-calcined method using calcium silicate residue of potassium feldspar after extraction of potassium and alumina. The effects of modifier and calcined temperature on the phase composition, morphology and microstructure were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that the phase of samples with different modifier processing is wollastonite-2M, while CTAB as modifier can avoid preferred orientation growth. The obtained wollastonite powder is spherical in morphology and well dispersed with the particle size of approximately 150nm.

2016 ◽  
Vol 680 ◽  
pp. 257-260
Author(s):  
Meng Yun Dong ◽  
Cheng Zhang ◽  
Jin Feng Xia ◽  
Hong Qiang Nian ◽  
Dan Yu Jiang

CaF2 nano-power was prepared by direct precipitation methods with Ca(NO3)2 and KF as raw materials. The influences of presintering temperature and sintering temperature on the particle size and distribution of CaF2 nano-power were studied by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM). This study provided an experimental method for preparation of CaF2 nano-power. The results show that the best presintering temperature of CaF2 nano-power is 500°C and the best sintering temperature of CaF2 ceramic is 900°C.


2010 ◽  
Vol 03 (03) ◽  
pp. 185-188 ◽  
Author(s):  
XIAOYUN ZHAN ◽  
ZHAOHUI LI ◽  
JIAOJUN TANG ◽  
QIZHEN XIAO ◽  
GANGTIE LEI ◽  
...  

Highly crystallized and microsized particles of LiNi0.5Mn1.5O4 spinels with different morphologies have been successfully synthesized using polystyrene (PS) as the sacrificial template, and were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical measurement. The spinels obtained at 700°C possess abundant porosity with about 200 nm in diameter, while the spinels calcined at 900°C exhibit a well-defined polyhedral morphology with particle size ranged from 0.2 to 2 μm. The materials prepared at 900°C display an excellent cycling performance due probably to better crystallinity and small particle size.


2010 ◽  
Vol 177 ◽  
pp. 9-11 ◽  
Author(s):  
Jie Song ◽  
Bing Xu ◽  
De Xin Huang ◽  
Cai Xia Li ◽  
Qiang Li

In this paper, super fine LiMn2O4 powder was synthesized by mechanochemical method starting from Li2CO3 and Mn2O3. The structure, size and morphology of LiMn2O4 were explored with X-ray diffraction and scanning electron microscopy (SEM). The electrochemical properties of LiMn2O4 were studied in 2 mol/L (NH4)2SO4 solution. The result showed that pure spinel LiMn204 powder was prepared after 8h grinding with 3.0KW of power and the particle size was about 1µm. Cyclic vohammetry curve indicate LiMn2O4 electrode material has better capacitive performances.


2014 ◽  
Vol 2014 ◽  
pp. 1-10
Author(s):  
Sudarshan Singh ◽  
Sunil B. Bothara

Mucilage isolated from seeds of Manilkara zapota (Linn.) P. Royen syn. is a plant growing naturally in the forests of India. This mucilage is yet to be commercially exploited, and characterized as polymer. Various physicochemical methods like particle size analysis, scanning electron microscopy, thermal analysis, gel permeation chromatography, X-ray diffraction spectrometry, zeta potential, Fourier transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy have been employed to characterize this gum in the present study. Particle size analyses suggest that mucilage has particle size in nanometer. Scanning electron microscopy analysis suggests that the mucilage has irregular particle size. The glass transition temperature of the gum was observed to be 138°C and 136°C by differential scanning calorimetry and differential thermal analysis, respectively. The thermogravimetric analysis suggested that mucilage had good thermal stability. The average molecular weight of mucilage was determined to be 379180, by gel permeation chromatography, while the viscosity of mucilage was observed to be 219.1 cP. The X-ray diffraction spectrometry pattern of the mucilage indicates a completely amorphous structure. Elemental analysis of the gum revealed the contents of carbon, hydrogen, nitrogen, and sulfur to be 80.9 (%), 10.1 (%), 1.58 (%), and 512 (mg/kg), respectively. Mucilage had specific content of calcium, magnesium, potassium, lower concentrations of aluminum, cadmium, cobalt, lead, and nickel. The major functional groups identified from FT-IR spectrum include 3441 cm−1 (–OH), 1660 cm−1 (Alkenyl C–H & C=C Stretch), 1632 cm−1 (–COO–), 1414 cm−1 (–COO–), and 1219 cm−1 (–CH3CO). Analysis of mucilage by paper chromatography and 1D NMR, indicated the presence of rhamnose, xylose, arabinose, mannose, and fructose.


2012 ◽  
Vol 727-728 ◽  
pp. 9-13
Author(s):  
Suzana Arleno S. Santos ◽  
Eduardo Sousa Lima ◽  
Luis Henrique Leme Louro ◽  
Célio Albano da Costa

This study aimed to produce nanometric powders of alumina by sol-gel route. Six samples were produced by varying the amount of water for dilution of aluminum nitrate and the calcination temperature. The final products were evaluated by thermogravimetric analysis, scanning electron microscopy, X-ray diffraction and particle size. It could be noticed that, beyond the time of gelation and calcination temperature, the addition of water also influenced the average size of the clusters.


2010 ◽  
Vol 156-157 ◽  
pp. 1010-1013
Author(s):  
Yong Ping Pu ◽  
Yong Yong Zhuang ◽  
Kai Chen ◽  
Ning Xu

Pure MnNb2O6 powders was successfully prepared by hydrothermal method using Nb2O5•nH2O and Mn(NO3)2 as precursors and HCl, HF, NaOH, NH4OH solutions as mineralization agent. The phase composition and morphology of the prepared powder were characterized by X-ray diffraction and scanning electron microscopy. The effect of mineralizers on phase formation was investigated. The results show that the MnNb2O6 powders with crystallite size of ~24nm can be obtained with Mn(NO3)2 and Nb2O5•nH2O as precursors in neutral and alkaline solution at 200 for 168h. The particle size of the MnNb2O6 powder was ~300nm after heat treatment at a temperature of 600 . The SEM photographs show that the morphology of the MnNb2O6 powder are rod-like particles and the MnNb2O6 powders are highly dispersed.


Author(s):  
Amalia Ekaputri Hidayat ◽  
Setyo Sarwanto Moersidik ◽  
Sandyanto Adityosulindro

Coal burning process in steam powered electric generator plants functioned to generate electricity energy. This process produce kinds of waste, such as solid waste, waste water, and emission. One of the solid waste produced in this process is fly ash. Fly ash is categorized as hazardous waste, it also can buildup in the landfill because of its massive production. However, fly ash has the potential as a raw material to produce synthetic zeolite because it contains metal oxide which is quite high. In this study, class F coal fly ash was synthesized by combining hydrothermal and fusion method. Synthesized fly ash and zeolite are characterized so that the chemical composition can be analyzed by X-ray Fluorescence; the mineralogy analyzed by X-ray Diffraction; the surface morphology analyzed by Scanning Electron Microscopy; and the particle size analyzed by Particle Size Analyzer. The synthesis of zeolite from coal fly ash in this study result hydroxy-sodalite zeolite type. In addition, this synthesis process increases the surface area of the previous fly ash. From the characteristics of zeolite from this synthesis it can be conclude that this zeolite can be approved as an adsorbent for the removal of liquid or gas pollutants in environmental technology applications with further research. ABSTRAKProses yang terjadi pada Pembangkit Listrik Tenaga Uap untuk menghasilkan energi listrik adalah melalui unit proses pembakaran batubara. Proses ini akan menghasilkan limbah padat, cair, maupun udara. Salah satu limbah padat yang dihasilkan adalah abu layang. Limbah abu layang ini dikatagorikan limbah bahan berbahaya dan beracun, serta dapat terjadinya penumpukan di tempat penimbunan akhir karena produksinya yang sangat tinggi. Namun, abu layang memiliki potensi sebagai bahan baku dalam memproduksi zeolit sintetik karena kandungan oksida logamnya yang cukup tinggi. Pada penelitian ini, abu layang batu bara kelas F disintesis dengan metode gabungan fusi-hidrotermal. Abu layang dan zeolit yang disintesis dikarakterisasi agar dapat dianalisis komposisi kimianya dengan X-ray Flourescence; mineraloginya dengan X-ray Diffraction; morfologi permukaan dengan Scanning Electron Microscopy; serta distribusi partikel dengan Particle Size Analyzer. Proses sintesis zeolit dari abu layang batubara pada penelitian ini menghasilkan zeolit jenis hidroksi sodalit. Selain itu, proses sintesis ini meningkatkan luas permukaan dari abu layang sebelumnya. Dari karakteristik zeolit hasil sintesis ini dapat disimpulkan bahwa zeolit ini dapat berpotensi sebagai adsorben untuk penyisihan polutan cair maupun gas pada aplikasi teknologi lingkungan dengan penelitian lebih lanjut.Kata kunci : abu layang; zeolit; hidroxi-sodalit; sintesis; fusi-hidrotermal


1991 ◽  
Vol 245 ◽  
Author(s):  
Carol L. Kilgour

ABSTRACTFluidized bed combustion (FBC) residues from four Iowa power plants were characterized to provide background with respect to chemical, physical, mineralogical and microstructural parameters that might affect their utilization potential. Methodologies used include: bulk chemical analysis; grain size analysis; specific gravity determination; mineralogical analysis by x-ray diffraction; scanning electron microscopy; and thermal analysis.Chemical analysis of the major components showed the separation of the constituents during combustion. The bottom ash is derived from the calcined and partly sulfated limestone, thus the concentration of calcium and sulfur compounds is greater. The fly ash however is derived mostly from the coal and therefore exhibits higher concentrations of coal ash components such as silica (SiO2), alumina (Al2O3), and ferric oxide (Fe2O3). The alkalis appear to be more concentrated in the fly ash.The measured particle size distributions of the bulk samples varied greatly, from extremely coarse (mean particle size ˜2000 μm) to fine (mean particle size ˜25 μm). The size distributions also varied in breadth. Specific gravities values recorded ranged from about 2.65 to about 3.05.X-ray diffraction analyses showed that most of the FBC by-products contain, as easily detectable crystalline components, only quartz, anhydrite and lime, and as is to be expected due to the low combustion temperatures, do not show broad peaks characteristic of glass in conventional fly ashes. Scanning electron microscopy revealed the FBC by-products to be extremely intricate mixtures of particles of complex and variable composition and internal structure.FBC by-products are shown to be extremely complex mixtures of particles of variable composition and internal structure. However, despite their local variation, useful results can be obtained by overall chemical and physico-chemical analyses of their composition. The exploitable properties of FBC residue include the somewhat cementitious nature and the granularity. However, their heterogeneous nature, lack of pozzolanic properties, and elevated sulfate content may limit their uses, especially in construction.


2014 ◽  
Vol 802 ◽  
pp. 338-342
Author(s):  
Claudinei dos Santos ◽  
Paula Cipriano da Silva ◽  
Luciane Carvalho de Paula ◽  
Alexandre Fernandes Habibe ◽  
Jefferson Fabrício C. Lins ◽  
...  

In this work, different commercial Co-Cr-Mo powders were used in selective laser sintering. Commercial powders with particle size distribution between 5 and 50μm were sintered by laser sintering, and characterized. The samples were characterized by X-ray diffraction, indicating Co as the only crystalline phase. Relative density was measured by Archimedes method showing values between 90 and 96% of TD, depending on the powder used. Scanning electron microscopy performed on the cross section of the sintered samples, indicates that the microstructural features are similar, but the surface finish of the samples differ significantly due to the morphology and size distribution of the starting powders used.


2011 ◽  
Vol 236-238 ◽  
pp. 1814-1817
Author(s):  
Hong Wang ◽  
Yan Jie ◽  
Hong Luo ◽  
Xue Feng

Monodisperse α-Fe2O3nanoparticles with average particle size of 110 nm were successfully prepared using olyvinylpyrrolidone (PVP) as surfactant via a novel hydrothermal route. The products were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM). The experiments results revealed that PVP and the concentration of NH4HCO3have played a crucial role in the formation of the monodisperse a-Fe2O3nanoparticles.


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