scholarly journals The Role of Mineral Matter in Concentrating Uranium and Thorium in Coal and Combustion Residues from Power Plants in Poland

Minerals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 312 ◽  
Author(s):  
Henryk R. Parzentny ◽  
Leokadia Róg
Keyword(s):  
Fly Ash ◽  
Power Plants ◽  
Fluorescence Analysis ◽  
Atomic Emission ◽  
Mineral Matter ◽  
X Ray Diffraction ◽  
X Ray ◽  
Waste Storage ◽  
Upper Silesian Coal Basin

Based on the results of tests on feed coal from the Lublin Coal and Upper Silesian Coal Basin and its fly ash and slag carried out using X-ray diffraction and X-ray fluorescence analysis, atomic emission spectroscopy, and scanning electron microscopy, it was found that in feeds, coal Th is associated with phosphates and U with mineral matter. The highest Th content was found in anhedral grains of monazite and in Al-Si porous particles of fly ash of <0.05 mm size; whereas in the slag, Th is concentrated in the massive Al-Si grains and in ferrospheres. U is mainly concentrated in the Al-Si surface of porous grains, which form a part of fly ash of <0.05 mm size. In the slag, U is to be found in the Al-Si massive grains or in a dispersed form in non-magnetic and magnetic grains. Groups of mineral phase particles have been identified that have the greatest impact on the content of Th and U in whole fly ash and slag. The research results contained in this article may be important for predicting the efficiency of Th and U leaching from furnace waste storage sites and from falling dusts to soils and waters.

Total reflection X-ray fluorescence analysis of fly ash from Bulgarian coal-fired power plants

2015 ◽  
Vol 69 (5) ◽  
Author(s):  
Albena K. Detcheva ◽  
Svilen E. Mitsiev ◽  
Paunka S. Vassileva ◽  
Juri H. Jordanov ◽  
Metody G. Karadjov ◽  
...  
Keyword(s):  
Fly Ash ◽  
Power Plants ◽  
Coal Fly Ash ◽  
Internal Standard ◽  
Fluorescence Analysis ◽  
Total Reflection ◽  
X Ray

AbstractThe contents of Cl, Ca, K, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Rb, Sr, Ba and Pb in raw coal fly ash from five Bulgarian power plants were determined by total reflection X-ray fluorescence (TXRF), using gallium as the internal standard. The samples were analysed as in slurry form in Triton

Coating Nano-Nickel Film on Cenospheres by Magnetic Sputtering Method

2013 ◽  
Vol 750-752 ◽  
pp. 2044-2047 ◽  
Author(s):  
Zheng Xu ◽  
Xiao Zheng Yu ◽  
Zhi Gang Shen
Keyword(s):  
Fly Ash ◽  
Power Plants ◽  
Particle Density ◽  
Hollow Spheres ◽  
Optical Microscope ◽  
Nickel Film ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nano Nickel ◽  
Magnetic Sputtering

The compacted even nanonickel film was coated on the surface of cenospheres of the fly ash from coal-burning power plants (3070 μm, particle density 0.3344g/cm3) which are hollow spheres with a shell consisting of quartz and mullite by magnetic sputtering technology. The optical microscope, scanning electric microscope and X-ray diffraction was use to examine the properties and the thickness of the coated nanonickel film. The results show that magnetic sputtering method is efficient to coat smooth, even and tightly combined nanonickel films on the cenospheres surface. The coated cenospheres can be widely used in industries.

scholarly journals Extraction of Al-Si master alloy and alumina from coal fly ash

2017 ◽  
Vol 53 (2) ◽  
pp. 155-162 ◽  
Author(s):  
A. Liu ◽  
Z. Shi ◽  
K. Xie ◽  
X. Hu ◽  
B. Gao ◽  
...  
Keyword(s):  
Fly Ash ◽  
Master Alloy ◽  
Power Plants ◽  
Coal Fly Ash ◽  
Raw Material ◽  
Aluminothermic Reduction ◽  
Chemical Compositions ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray

Coal fly ash from coal power plants is a potential raw material for the production of alumina. An objective aluminothermic reduction method for the preparation of Al-Si master alloy and alumina from coal fly ash was investigated. The kinetic analysis using non-isothermal differential scanning calorimetry indicated that the reduction of Al6Si2O13, Fe2O3, and TiO2 by aluminum in coal fly ash occurs at 1618 K, 1681 K, and 1754 K, respectively. Moreover, the influence of reaction temperature on product composition was studied. The phases and morphologies of the products obtained by the aluminothermic reduction of coal fly ash at 1373-1773 K were analyzed by X-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy, respectively. The results from X-ray diffraction show that no oxide reduction has taken place at 1373 K and 1473K, the compositions of the product obtained by aluminothermic reduction of fly ash at 1573K- 1673 K are Al2O3, mullite, Al and Si, while the compositions of the product at 1773 K are Al2O3, Al, and Si. In addition, the chemical compositions of Al-Si alloy obtained at 1773 K are 86.81 wt% Al and 13.19 wt% Si.

scholarly journals Effect of Alkali Activator on the Standard Consistency and Setting Times of Fly Ash and GGBS-Based Sustainable Geopolymer Pastes

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
M. Dineshkumar ◽  
C. Umarani
Keyword(s):  
Fly Ash ◽  
Setting Time ◽  
Fluorescence Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Alkali Activator ◽  
Setting Times ◽  
Granulated Blast Furnace Slag ◽  
Ft Ir ◽  
Alkaline Activator

In this study, an attempt has been made to study the effect of alkali activator on the standard consistency and setting times of low calcium fly ash (FA) and ground granulated blast furnace slag (GGBS)- based sustainable geopolymer pastes. Different proportions of FA and GGBS were blended into mixes of geopolymer paste using sodium hydroxide (SH) and sodium silicate (SS) as alkaline activator solution (AAS). Tests on geopolymer pastes for consistency and initial and final setting times were carried out for three different SH : SS ratios of 1 : 1, 1 : 2, and 1 : 3 for both 2.5 M (molarity) and 5.0 M of SH concentration. While increasing the molarity of SH, both consistency and setting time decreased. For all the blended binder mix, the setting time decreases with an increase in the quantity of SS in the alkali activator solution. An increase in the amount of GGBS content in the geopolymer blended binder mix increases the consistency and decreases the setting time. For both 2.5 M and 5 M blended geopolymer mixes, a decrease in the percentage of GGBS and an increase in the percentage of FA increased the setting time. Microstructural studies such as X-ray fluorescence analysis (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FT-IR) analyses were carried out, and the results are presented. The FT-IR spectra for the blended binder mixes demonstrated the formation of geopolymerization and the presence of the functional groups.

X-Ray Diffraction Analysis of Fly ASH

1987 ◽  
Vol 31 ◽  
pp. 331-342 ◽  
Author(s):  
G.J. McCarthy ◽  
D.M. Johansen ◽  
S.J. Steinwand ◽  
A. Thedchanamoorthy
Keyword(s):  
Fly Ash ◽  
Diffraction Analysis ◽  
Power Plants ◽  
Aluminosilicate Glass ◽  
Low Rank ◽  
X Ray Diffraction ◽  
Crystalline Phases ◽  
X Ray ◽  
Calcium Aluminosilicate ◽  
Intensity Ratios

AbstractMethods for, and results from, x-ray diffraction analysis of large numbers of fly ash samples obtained from U.S. power plants are described. Qualitative XRD indicates that low-calcium/Class F fly ash (usually derived from bituminous coal) consists typically of the crystalline phases quartz, mullite, hematite and magnetite in a matrix of aluminosilicate glass. Highcalcium fly ash (derived from low-rank coal) has a much more complex assemblage of crystalline phases that typically includes these four phases plus lime, periclase, anhydrite, alkali sulfates, tricalcium aluminate, dicalcium silicate, melilite, merwinlte and a sodalite-structure phase. Glass compositions among the particles are more heterogeneous and range from calcium aluminate to sodium calcium aluminosilicate, Every ash studied Is mixed with an internal Intensity standard (rutile) so that Intensity ratios can be used to make comparisons of the relative amounts of crystalline phases. An error analysis was performed to define the level of uncertainty in making these comparisons. These intensity ratios will be used for quantitative XRD phase analyses when reference intensity ratios for each fly ash phase become available.

scholarly journals Distribution of Some Ecotoxic Elements in Fuel and Solid Combustion Residues in Poland

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1131 ◽  
Author(s):  
Henryk R. Parzentny ◽  
Leokadia Róg
Keyword(s):  
Fly Ash ◽  
Inductively Coupled Plasma ◽  
Power Plants ◽  
Dendritic Structure ◽  
Atomic Emission ◽  
Magnetic Fraction ◽  
Petrographic Composition ◽  
X Ray ◽  
Distribution Of Elements ◽  
Combustion Residues

The purpose of this paper is to assess the content and distribution of some elements in coal from two bituminous coal basins and in fly ash and slag derived from combustion of the coals in six power plants in Poland. The petrographic composition and distribution of elements were characterized in the tested samples, using reflected light microscope, X-ray powder diffractometer, inductively coupled plasma atomic emission spectroscopy, and scanning electron microscope with energy dispersive X-ray. The highest content of elements in coal occurs in siderite. In Al-Si particles, as well as in magnetite with skeletal and dendritic structure crystallized on the surface of Al-Si microspheres or cenospheres included in fly ash size < 0.05 mm and in the magnetic fraction of slag, the highest content of elements was noted. Due to the content of elements, fly ash and slag were considered to be neutral for the soil environment. Correlations, which have not been described before, have been observed between the likely mode of binding of some elements in coal and their distribution in fly ash and slag. These correlations could be of particular value when predicting the content and distribution of elements in combustion residues and in the assessment of their environmental toxicity.

Quantitative X-Ray Fluorescence Analysis for Fly Ash Samples

1983 ◽  
Vol 27 ◽  
pp. 497-504
Author(s):  
Scott Schlorholtz ◽  
Mustafa Boybay
Keyword(s):  
Fly Ash ◽  
Sample Preparation ◽  
Power Plants ◽  
Fluorescence Analysis ◽  
Complex Problem ◽  
Point Of View ◽  
Fly Ashes ◽  
X Ray ◽  
Minor Elements ◽  
Minimal Sample

The disposal of fly ash from coal burning power plants is rapidly becoming an environmentally complex problem. Recently though, the attitude towards fly ash use has been changing from a disposal oriented point of view to a more rational position which considers fly ash as a resource to be recycled. One major hinderance of fly ash use has been the extreme variability of composition that exists between fly ashes produced at different power plants. This variability makes the analysis of fly ash very important.The most common methods currently used for fly ash analysis are atomic absorption or wet chemistry methods defined in ASTM C311. Both methods tend to be expensive, time consuming, and sample preparation is both tedious and critical for some elements. In this study X-ray fluorescence (QXRF) is used for the quantitative analysis of the major and minor elements found in “typical” fly ashes. The method, which is computer controlled, is quick, reliable, and requires minimal sample preparation.

Role of the Structure and Electronic Properties of Fe2O3-MoO3 Catalyst on the Dehydration of Isopropyl Alcohol

1993 ◽  
Vol 58 (7) ◽  
pp. 1591-1599 ◽  
Author(s):  
Abd El-Aziz A. Said
Keyword(s):  
Active Sites ◽  
Isopropyl Alcohol ◽  
Oxide Catalyst ◽  
Flow System ◽  
Charge Carriers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalyst Composition ◽  
Surface Active

Molybdenum oxide catalyst doped or mixed with (1 - 50) mole % Fe3+ ions were prepared. The structure of the original samples and the samples calcined at 400 °C were characterized using DTA, X-ray diffraction and IR spectra. Measurements of the electrical conductivity of calcined samples with and without isopropyl alcohol revealed that the conductance increases on increasing the content of Fe3+ ions up to 50 mole %. The activation energies of charge carriers were determined in presence and absence of the alcohol. The catalytic dehydration of isopropyl alcohol was carried out at 250 °C using a flow system. The results obtained showed that the doped or mixed catalysts are active and selective towards propene formation. However, the catalyst containing 40 mole % Fe3+ ions exhibited the highest activity and selectivity. Correlations were attempted to the catalyst composition with their electronic and catalytic properties. Probable mechanism for the dehydration process is proposed in terms of surface active sites.

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