Synthesis of NaY zeolite of high phase purity from kaolin

1990 ◽  
Vol 26 (8) ◽  
pp. 397-399 ◽  
Author(s):  
A. V. Takhtamysheva ◽  
L. D. Konoval'chikov ◽  
B. K. Nefedov

2009 ◽  
Vol 311 (11) ◽  
pp. 3130-3132 ◽  
Author(s):  
R. Ohba ◽  
K. Mitamura ◽  
K. Shimomoto ◽  
T. Fujii ◽  
S. Kawano ◽  
...  


2019 ◽  
Vol 31 (19) ◽  
pp. 1900568 ◽  
Author(s):  
Jing Peng ◽  
Yuhua Liu ◽  
Xiao Luo ◽  
Jiajing Wu ◽  
Yue Lin ◽  
...  




2015 ◽  
Vol 9 (3) ◽  
pp. 131-138 ◽  
Author(s):  
Karanja Avinash ◽  
Madireddy Suresh ◽  
Asit Khanra ◽  
Roy Johnson

Pure and Li-doped sodium ?-alumina (NaMg0.67Al10.33O17) ceramics were prepared from the stoichiometric mixture of raw powders. Pellets and tubes were formed from the precursor (NBA-1S) and preformed sodium ?-alumina powder through compaction and extrusion processing, respectively. The obtained specimens were finally sintered to dense ceramics. The ceramics were comparatively evaluated for their density, microstructure, phase formation and electrical properties. Both tubes and pellets processed with the preformed sodium ?-alumina powder (NBA-2S) showed enhanced densification along with relatively better phase purity and crystallinity. The ceramics prepared from the preformed powder exhibited higher density of 94-95% TD (theoretical densities) in comparison to the ceramics processed from the raw mixture (NBA-1S) with a density of 85-87%TD, which are complemented well through fractographs and microstructures. The ceramics processed using the preformed sodium ?-alumina (NBA-2S) also exhibited high room temperature AC conductivity of 1.77?10-4 S/cm (1MHz) with an increasing trend with temperature. The higher ionic conductivity at all temperatures in NBA-2S than in NBA-1S ceramics can be attributed to the relatively high phase purity, crystallinity and higher density values of NBA-2S ceramics.



Minerals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 520
Author(s):  
Bing-Sheng Yu ◽  
Yuh-Ruey Wang ◽  
Wei Lo ◽  
Yi-Yu Liu

Smectites are a major type of clay minerals. Hydrothermally synthesized smectites have become a major research topic because of the unstable quality or excessive impurity of natural smectites. The high-phase purity and yield of hydrothermally synthesized smectites are vital in advanced industries and materials applications. In this study, a Taguchi orthogonal array was integrated with eight factors to avoid biased experimental results, thus creating relatively robust factor portfolios to investigate the effects of temperature, alkali sources, and the magnesium (Mg)/aluminum (Al) ratio on the phase purity and yield of hydrothermally synthesized smectites. The synthesized environment was mainly established using trioctahedral smectites based on the formula Na2x(Al2(1−x)Mg2x□)Si4O10(OH)2X-ray diffraction and Rietveld refinement were used for the quantitative analysis of the products’ mineral facies and calculating the synthesized smectites’ phase purity and yield. The Taguchi method was employed to calculate each factor’s effect on the product quality. The results indicated that among the numerous factor portfolios, a relatively high temperature, ammonia solution as the alkali source, and a relatively high Mg/Al ratio were conducive to enhanced phase purity and yield of synthesized smectites. The optimized products of the synthesized smectites achieved a phase purity of 92.5% and a yield of 88.3%.



2020 ◽  
Author(s):  
Saiyue Liu ◽  
Chang Zhou ◽  
You Wang ◽  
Eongyu Yi ◽  
Weimin Wang ◽  
...  


2010 ◽  
Vol 2010 ◽  
pp. 1-6
Author(s):  
K. B. Paul ◽  
G. I. Athanasopoulos ◽  
C. C. Doumanidis ◽  
C. Rebholz

Novel semiconducting Germanium-Dysprosium nanowires are fabricated by a combined two-step method, which consists of initial arc-melting of the elemental constituents into a pellet and its heat treatment, followed by thermal vapor transport of the powdered pellet in a tube reactor for fabrication of the nanowires. The nanomaterials are fabricated on gold nucleation seeds on Si/SiO2substrates. The thermodynamic conditions in the reactor are carefully chosen to produce wires with diameters in a narrow, specific range. This nanofabrication method ensures high phase purity and crystallinity of nanowires. Based on the results and theoretical work, it is concluded that the fabricatedGe98Dy2materials are in a glassy state below 20 K.



2018 ◽  
Vol 18 (5) ◽  
pp. 6-11
Author(s):  
M. R. Aglyullin ◽  
Z. R. Khayrullina ◽  
A. V. Fayzullin ◽  
A. I. Petrov ◽  
A. A. Badretdinova ◽  
...  

The influence of temperature and ageing of initial aluminophosphate gels on their chemical and phase composition was studied. The hydrated oxide (boehmite) was used as the source of aluminum to prepare gels containing ammonium phosphate, undissolved pseudoboehmite and amorphous aluminophosphate in different proportions. The gel with predominant amorphous aluminophosphate was shown to provide selective crystallization of high phase purity AlPO4-11 with the crystallinity degree close to 100 %. The developed method for preparation of these disperse molecular aluminophosphate sieves AlPO4-11 is a step to crystallization of silicoaluminophosphates SAPO-11 that are promising Russian catalysts for industrial processes of hydroisomerization of n-paraffins used for manufacturing of Arctic diesel fuel, III group oils and isomerization of butenes.





2006 ◽  
Vol 61 (3) ◽  
pp. 342-345 ◽  
Author(s):  
Günther Engel ◽  
Uwe Hilsenbek

Abstract Well crystallized lepidocrocite (γ-FeOOH) with high phase purity can be prepared by precipitation from homogeneous solution. FeCl2 is oxidized with NaClO3 while heating the common solution slowly from 20 to 75 °C. Due to the buffer pyridine/HCl the pH-value changes only from 6.3 to 5.3. The product with the specific surface of about 16 m2/g has been characterized by several methods, especially by thermal analysis.



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