Quantitative X-Ray Fluorescence Analysis for Fly Ash Samples

1983 ◽  
Vol 27 ◽  
pp. 497-504
Author(s):  
Scott Schlorholtz ◽  
Mustafa Boybay

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.

2015 ◽  
Vol 69 (5) ◽  
Author(s):  
Albena K. Detcheva ◽  
Svilen E. Mitsiev ◽  
Paunka S. Vassileva ◽  
Juri H. Jordanov ◽  
Metody G. Karadjov ◽  
...  

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


Minerals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 312 ◽  
Author(s):  
Henryk R. Parzentny ◽  
Leokadia Róg

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.


Minerals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 105 ◽  
Author(s):  
James C. Hower ◽  
John G. Groppo ◽  
Prakash Joshi ◽  
Dorin V. Preda ◽  
David P. Gamliel ◽  
...  

In this study, Central Appalachian coal-derived fly ashes from two power plants were beneficiated in a pilot-scale facility in order to produce a product with a relatively consistent concentration of rare earth elements (REE). The <200-mesh final fly ash product was produced by removing the carbon- and Fe-rich particles prior to screening at 200 mesh (75 µm). The Plant D fly ash had high concentrations of CaO and SO3, which were diminished through the two months when the ash was being beneficiated, representing a consequence of the heat, humidity, and excessive rainfall in the Kentucky summer. The high CaO and SO3 concentrations through the early runs likely contributed to the lower REE in the <200-mesh products of those runs. Of the non-REE minor elements, Ba, V, Mn, Zn, and As showed the greatest between-run variations within the runs for each plant. The overall REE concentrations proved to be similar, both on a between-run basis for the individual fly ash sources and on a between-plant basis. Variations in fly ash quality will occur in larger-scale operations, so on-going attention to the fly ash quality and the response of the fly ash to beneficiation is necessary. Changes in the Plant D fly ash with time imply that both the freshness of the original ash and the length and conditions of its storage at the site of beneficiation could be factors in the quality and consistency of the processed fly ash.


2012 ◽  
Vol 18 (3) ◽  
pp. 373-383 ◽  
Author(s):  
Anja Terzic ◽  
Zagorka Radojevic ◽  
Ljiljana Milicic ◽  
Ljubica Pavlovic ◽  
Zagorka Acimovic

The disposal of the fly ash generated in coal based power-plants may pose a significant risk to the environment due to the possible leaching of hazardous pollutants, such as toxic metals. Also, there is a risk of leaching even when fly ash is built-in the construction composites. Fly ashes from various landfills were applied in several composite samples (mortar, concrete and brick) without any physical or thermal pre-treatment. The leachability of the potentially toxic pollutants from the fly ash based products was investigated. The leaching behavior and potential environmental impact of the 11 potentially hazardous elements was tracked: Pb, Cd, Zn, Cu, Ni, Cr, Hg, As, Ba, Sb and Se. A detailed study of physico-chemical characteristics of the fly ash, with accent on trace elements and the chemical composition investigation is included. Physico/chemical properties of fly ash were investigated by means of X-ray fluorescence, differential thermal analysis and X-ray diffraction methods. Scanning electron microscope was used in microstructural analysis. The results show that most of the elements are more easily leachable from the fly ash in comparison with the fly ash based composites. The leaching of investigated pollutants is within allowed range thus investigated fly ashes can be reused in construction materials production.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1267
Author(s):  
David Längauer ◽  
Vladimír Čablík ◽  
Slavomír Hredzák ◽  
Anton Zubrik ◽  
Marek Matik ◽  
...  

Large amounts of coal combustion products (as solid products of thermal power plants) with different chemical and physical properties cause serious environmental problems. Even though coal fly ash is a coal combustion product, it has a wide range of applications (e.g., in construction, metallurgy, chemical production, reclamation etc.). One of its potential uses is in zeolitization to obtain a higher added value of the product. The aim of this paper is to produce a material with sufficient textural properties used, for example, for environmental purposes (an adsorbent) and/or storage material. In practice, the coal fly ash (No. 1 and No. 2) from Czech power plants was firstly characterized in detail (X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDX), particle size measurement, and textural analysis), and then it was hydrothermally treated to synthetize zeolites. Different concentrations of NaOH, LiCl, Al2O3, and aqueous glass; different temperature effects (90–120 °C); and different process lengths (6–48 h) were studied. Furthermore, most of the experiments were supplemented with a crystallization phase that was run for 16 h at 50 °C. After qualitative product analysis (SEM-EDX, XRD, and textural analytics), quantitative XRD evaluation with an internal standard was used for zeolitization process evaluation. Sodalite (SOD), phillipsite (PHI), chabazite (CHA), faujasite-Na (FAU-Na), and faujasite-Ca (FAU-Ca) were obtained as the zeolite phases. The content of these zeolite phases ranged from 2.09 to 43.79%. The best conditions for the zeolite phase formation were as follows: 4 M NaOH, 4 mL 10% LiCl, liquid/solid ratio of 30:1, silica/alumina ratio change from 2:1 to 1:1, temperature of 120 °C, process time of 24 h, and a crystallization phase for 16 h at 50 °C.


Sign in / Sign up

Export Citation Format

Share Document