Factors Influencing Mullite Formation in Refractory Grog

2021 ◽  
Vol 321 ◽  
pp. 149-155
Author(s):  
Lenka Nevřivová ◽  
David Zemánek
Keyword(s):  
Rietveld Method ◽  
Refractory Clay ◽  
Raw Material ◽  
High Alumina ◽  
Quantitative Phase Analysis ◽  
Mullite Formation ◽  
Factors Influencing ◽  
Different Temperatures ◽  
Silica Alumina ◽  
Fireclay Refractory

The mineral mullite has many outstanding refractory properties. The content of aluminum oxide in the raw material is the basic factor influencing the content of mullite in the final product. Depending on Al2O3 content, silica-alumina materials can be divided into fireclay and high-alumina with the Al2O3 content of 45 % and more. The study describes the influence of raw material, the influence of homogenization of raw material and influence of firing temperature on the mullite formation in fireclay refractory material. Three kinds of refractory clay with different chemical composition were used as raw material for fireclay grog production. Three kinds of homogenization and three different temperatures were studied as factors influencing mullite formation. Powder X-ray diffraction was used to determine mullite content in material. Quantitative phase analysis was conducted by the Rietveld method. Mullite crystals morphology was observed by scanning electron microscopy.

Research on Mullite-Corundum-Aluminium Titanate Composite

2013 ◽  
Vol 652-654 ◽  
pp. 308-311
Author(s):  
Yuzhou Huang ◽  
Jing Long Bu ◽  
Yue Jun Chen ◽  
Zhi Fa Wang
Keyword(s):  
Bending Strength ◽  
Weight Ratio ◽  
Clay Content ◽  
Refractory Clay ◽  
Apparent Porosity ◽  
Raw Material ◽  
High Alumina ◽  
Strength Increase ◽  
Aluminium Titanate ◽  
Shock Resistance

Mullite-aluminium titanate-corundum composite was prepared at 1300°C with refractory clay, aluminium titanate and high alumina grog as raw material, molded at pressure of 50MPa. Effect of raw material ratio on sintering and themal shock resistance of the mullite-aluminium titanate-corundum composite was researched by measurements of apparent porosity, bending strength and residual strength after water-cool, and analyses of XRD and SEM. The results showed that as refractory clay content, apparent porosity of samples decrease, bulk density and bending strength increase. When the weight ratio of refractory clay, aluminium titanate and high alumina grog is 60/10/30, themal shock resistance of sample is excellent, The XRD and SEM analysis results indicated that the mechanical and thermal proprieties are relative to the microstructure and crystal phases of the composite materials.

Syntheses and characterization of zeolites K-F and W type using a diatomite precursor

2014 ◽  
Vol 78 (5) ◽  
pp. 1209-1225 ◽  
Author(s):  
D. Novembre ◽  
C. Pace ◽  
D. Gimeno
Keyword(s):  
Potassium Hydroxide ◽  
Rietveld Method ◽  
Morphological Characterization ◽  
Raw Material ◽  
Quantitative Phase Analysis ◽  
Cell Parameters ◽  
Chemical Treatments ◽  
Natural Rock

AbstractZeolites K-F and W (EDI and MER types) were synthesized hydrothermally using a natural rock as raw material. Chemical treatments were carried out on a diatomitic rock (containing opaline silica) from Crotone (Calabria, Italy) in order to separate/obtain potassium silicate, a reagent necessary for synthesizing zeolites. Synthesis experiments were performed by mixing the obtained siliceous solution with potassium hydroxide and alumina in varying proportions at 150°C and room pressure. Four synthesis series were performed to form zeolite K-F (EDI) and zeolite W (MER).The chemical-physical and morphological characterization of the zeolite phases were carried out. Cell parameters were calculated using the Rietveld method. Infrared, thermal and nuclear magnetic resonance (29Si) experiments confirmed the high quality of the zeolite products. The amorphous phase in the synthesis powders was estimated with quantitative phase analysis using the combined Rietveld and reference intensity ratio methods.

The Way of Utilization of Fused Corundum Dust Waste for the High-Alumina Chamotte Production

2021 ◽  
Vol 316 ◽  
pp. 100-104
Author(s):  
Irina Pavlova ◽  
Anna Getman ◽  
Elena Farafontova
Keyword(s):  
Waste Product ◽  
Refractory Clay ◽  
Raw Material ◽  
Production Waste ◽  
High Alumina ◽  
Commercial Alumina ◽  
Chamotte Production ◽  
The Way

High-alumina chamotte with an Al2O3 content of more than 62% is a desirable raw material to produce high-alumina refractories. The production of high-alumina aggregate (chamotte) is carried out in various ways, using plastic or semi-dry technology for briquetting from commercial alumina and refractory clay. When grinding fused corundum, the dust containing 93–95% Al2O3 is formed; it is currently a substandard material. It is of interest to involve this waste product in the production of high-alumina chamotte. The developed technology allows obtaining the desirable material and utilizing production waste. In this project the briquetting parameters to produce high-alumina chamotte using corundum waste and refractory enriched kaolin were determined.

scholarly journals Rheological and Microbiological Characteristics of Hops and Hot Trub Particles Formed during Beer Production

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 681
Author(s):  
Monika Sterczyńska ◽  
Marek Zdaniewicz ◽  
Katarzyna Wolny-Koładka
Keyword(s):  
Rheological Properties ◽  
Raw Materials ◽  
Raw Material ◽  
Microbiological Analysis ◽  
Waste Products ◽  
Low Viscosity ◽  
Post Process ◽  
High Shear Rates ◽  
Different Temperatures ◽  
Beer Production

During the production of beer, and especially beer wort, the main wastes are spent grain and hot trub, i.e., the so-called “hot break.” Combined with yeast after fermentation, they represent the most valuable wastes. Hot trub is also one of the most valuable by-products. Studies on the chemical composition of these sediments and their rheological properties as waste products will contribute to their effective disposal and even further use as valuable pharmaceutical and cosmetic raw materials. So far, hot trub has been studied for morphology and particle distribution depending on the raw material composition and beer wort extract. However, there are no preliminary studies on the rheological properties of hot trub and hops. In particular, no attention has yet been paid to the dependence of these properties on the hop variety or different protein sources used. The aim of this study was to examine the effect of different hopping methods on hot trub viscosity and beer wort physicochemical parameters. Additionally, the hop solutions were measured at different temperatures. A microbiological analysis of hop sediments was also performed to determine the post-process survival of selected microorganisms in these wastes. For manufacturers of pumps used in the brewing industry, the most convenient material is that of the lowest viscosity. Low viscosity hot trub can be removed at lower velocities, which reduces costs and simplifies washing and transport. The sediments also had similar equilibrium viscosity values at high shear rates.

Conductivity Characterizationof Iron Oxide Doped 8 mol% Yttria Stabilized Zirconia

2018 ◽  
Vol 280 ◽  
pp. 58-64
Author(s):  
Tinesha Selvaraj ◽  
Johar Banjuraizah ◽  
S.F. Khor ◽  
M.N. Mohd Zainol
Keyword(s):  
Solid Oxide Fuel Cells ◽  
Solid Electrolytes ◽  
Electrode Materials ◽  
Rietveld Method ◽  
Quantitative Phase Analysis ◽  
X Ray Diffraction ◽  
Solid Electrode ◽  
Short Sample ◽  
X Ray ◽  
Rietveld Quantitative Phase Analysis

A facile strategy was proposed to incorporate the dopant Fe into 8YSZ-based material, which can be potentially applied as solid electrode materials for Solid Oxide Fuel Cells (SOFC). In this study, 8YSZ powder was investigated in terms of densification, conductivity and thecrystal structure as a solid electrolytes. Therefore, varying mol% of Fe included 1, 2, and 3 were prepared for investigation. The crystalline structure of the pristine and Fe doped samples were characterized by X-ray diffraction (XRD) and the phase contents were evaluated by using the Rietveld method. Rietveld quantitative phase analysis demonstrates that the monoclinic-ZrO2phase increases (12.8 wt% to 39.7 wt%) as the concentration of Fe increases, while the amount of tetragonal-ZrO2phase drop (40.4 wt% to 11.9 wt%) dramatically. Sintering activity was applied to improve incorporation of the 8YSZ powder and the dopant Fe where the relative density increases from 77% to 92%. Sample YSZ-2Fe has been fitted with CPE equivalent circuit and achieved 6.251 x 10-6S/cm at 300 °C in air. However, it was found that conductivity levels decreased as the mol% of Fe increased. In short, sample YSZ-2Fe ceramic demonstrated good results in terms of densification (92.09%), cubic ZrO2phase (22 wt%) and conductivity 6.251 x 10-6S/cm.

scholarly journals Intensification of the extraction process of phenolic compounds from Acorus calamus leaves

2021 ◽  
pp. 4-10
Author(s):  
Oleksiy Andryushayev ◽  
Olena Ruban ◽  
Yuliia Maslii ◽  
Inna Rusak
Keyword(s):  
Phenolic Compounds ◽  
Raw Materials ◽  
Extraction Process ◽  
Raw Material ◽  
Acorus Calamus ◽  
Optimal Conditions ◽  
Ultrasonic Action ◽  
Different Temperatures ◽  
Method Of Extraction ◽  
Temperature Time

The aim. To determine the intensified method of extraction of phenolic compounds from Acorus calamus leaves and optimal conditions for the process. Materials and methods. In order to develop the optimal intensified method of extraction samples were prepared in different conditions of raw materials-extractant ratio, temperature, time and multiplicity. As a raw materials spectrophotometrically pre-standardized Acorus calamus leaves were used. The extraction was carried out in a hermetically sealed ultrasonic extraction reactor PEX 1 (REUS, Contes, France). As the criteria of extraction efficiency were indicators of dry residue and total amount of flavonoids determined using methods described in State Pharmacopoeia of Ukraine. The amount of flavonoids was determined spectrophotometrically on a certified device Specord 200 (Analytik Jena, Germany). Results. According to our research results it was found that ultrasonic action and addition of surfactant significantly improves the efficiency of the extraction process. The optimal conditions for the process were determined. Experimentally proved that the rational raw material-extractant ratio is 1:15. Comparative study of the extraction process with different temperatures showed that the highest amount of extractives is achieved at temperature 70 °C and 45 min of duration. The optimal extraction multiplicity is 3. Conclusions. As a result of the study, the intensified extraction method for Acorus calamus leaves – re-maceration with ultrasound – was established. The conducted researches allowed to develop the method of extraction, expedient in the conditions of the modern pharmaceutical industry.

scholarly journals Structural Properties Analysis of Mg-β-TCP by X-ray Powder Diffraction with the Rietveld Refinement

2020 ◽  
Vol 9 (4) ◽  
pp. 1562-1568
Keyword(s):  
Powder Diffraction ◽  
Rietveld Method ◽  
Quantitative Phase Analysis ◽  
Structural Refinement ◽  
Osteoporosis Therapy ◽  
X Ray ◽  
Cell Parameters ◽  
Biomineralization Process ◽  
Resultant Powder ◽  
Rapid Reaction

The incorporation of magnesium in the synthetic apatite has been associated with the biomineralization process and osteoporosis therapy in humans and animals. β-tricalcium phosphate (β-TCP) is one of the most common bioceramics widely applied in bone cement and implants. In this work, Ca-deficient apatite (CDA) with a theoretical 0.08 Mg/(Ca+Mg) ratio was synthesized by the rapid reaction between Ca(OH)2, MgCl2.6H2O and H3PO4 at 40°C and the resultant powder calcined at 650 °C for 10h. X-ray powder diffraction analysis (XRD), in combination with the Rietveld method (Fullprof-suite), was employed for quantitative phase analysis and structural refinement. The results of XRD indicate that magnesium can substitute for calcium into a β-TCP structure inducing a reduction of the cell parameters and the compound crystallizes in the rhombohedral R3c structure, with the following unit cell constants: a = b = 10.3560 Å, c = 37.1718 Å, and cell volume V = 3452.44. The analysis indicated that the substitution of Mg2+ on the M(4) and M(5) sites were, approximately, 2.61 and 6.97 mol%, corresponding to the Ca2.72(MgIV0.07, MgV0.21)(PO4)2 stoichiometric formula and 0.09 Mg/(Ca+Mg) ratio.

scholarly journals The Effects of Temperature on the Hydrothermal Synthesis of Hydroxyapatite-Zeolite Using Blast Furnace Slag

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2131 ◽  
Author(s):  
G.U. Ryu ◽  
G.M. Kim ◽  
Hammad R. Khalid ◽  
H.K. Lee
Keyword(s):  
Blast Furnace ◽  
Hydrothermal Synthesis ◽  
Blast Furnace Slag ◽  
Raw Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Type Zeolite ◽  
Effects Of Temperature ◽  
Furnace Slag

Blast furnace slag, an industrial by-product, is emerging as a potential raw material to synthesize hydroxyapatite and zeolite. In this study, the effects of temperature on the hydrothermal synthesis of hydroxyapatite-zeolite from blast furnace slag were investigated. Specimens were synthesized at different temperatures (room temperature, 50, 90, 120, or 150 °C). The synthesized specimens were analyzed qualitatively and quantitatively via X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), BET/BJH, and scanning electron microscopy/energy dispersive using X-ray analysis (SEM/EDX). It was found that the hydroxyapatite phase was synthesized at all the reaction temperatures, while faujasite type zeolite appeared in the specimens synthesized at 90 and 120 °C. Moreover, faujasite was replaced by hydroxysodalite in the specimens synthesized at 150 °C. Additionally, the crystals of the hydroxyapatite tended to become larger and total crystallinity increased as the reaction temperature increased.

The cracking of cyclo pentene on a silica-alumina catalyst

1960 ◽  
Vol 257 (1288) ◽  
pp. 132-145 ◽  
Keyword(s):  
Molecular Weight ◽  
Catalytic Cracking ◽  
Slow Step ◽  
Static System ◽  
Surface Complexes ◽  
Temperature Range ◽  
Carbonium Ions ◽  
Wide Range ◽  
Different Temperatures ◽  
Silica Alumina

The cracking of cyclo pentene on silica-alumina was studied in a flow system over the temperature range 368 to 505 °C. The analysis of the products was carried out by gas-liquid chromatographic techniques and the design of the apparatus made it possible to measure the pressures of compounds of low molecular weight at a series of points along the catalyst bed. Partial analyses were made of the extremely wide range of products of high molecular weight collected at the end of the reactor for reactions at three different temperatures. The results obtained were sufficiently detailed to provide activation energies for the for­mation of a number of the products and for the decomposition of cyclo pentene and to per­mit the application of thermodynamical calculations to ascertain the source of substances such as cyclo pentane and methyl cyclo pentane. The results of the flow experiments together with a subsidiary experiment on the reactions which occurred to cyclo pentene at 68 °C on the catalyst in a static system indicated that the formation, polymerization and isomerization of the surface complexes to condensed six-membered ring systems must be extremely rapid processes in the temperature range required for the catalytic cracking of cyclo pentene. These processes probably occur through the formation of carbonium ions and consequently the formation of these ions is unlikely to be the slow step in the catalytic cracking of olefins. The rate of the cracking reaction may depend on the rate of decomposition of carbonium ions considerably larger in size than the original olefin.

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