scholarly journals Mineralogical and Environmental Geochemistry of Coal Combustion Products from Shenhuo and Yihua Power Plants in Xinjiang Autonomous Region, Northwest China

Minerals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 496 ◽  
Author(s):  
Wu ◽  
Li ◽  
Zhuang ◽  
Querol ◽  
Moreno ◽  
...  
Keyword(s):  
Fly Ash ◽  
Coal Combustion ◽  
Inductively Coupled Plasma ◽  
Power Plants ◽  
Environmental Geochemistry ◽  
Combustion Products ◽  
Coal Combustion Products ◽  
X Ray ◽  
Inductively Coupled ◽  
Xinjiang Autonomous Region

The mineralogical and geochemical characteristics of feed coals and coal combustion products (CCPs) from the Shenhuo and Yihua Power Plants in Xinjiang Autonomous Region, were studied by means of proximate analysis, Power X-ray diffraction (XRD), scanning electron microscopy with Energy Dispersive X-ray analyzer (SEM-EDX), inductively coupled plasma atomic emission spectrometry (ICP-MS) and inductively coupled plasma mass spectrometry (ICP-AES). The environmental geochemistry of CCPs was evaluated by Al-normalized enrichment factor as well as European Standard EN-12457 leaching test. Two feed coals have the characteristics of low sulfur content, medium to high volatiles matter yields, medium moisture content, super low to medium ash yield, medium to high calorific value and low mineral content. The main crystalline facies in fly ash and slag are quartz and mullite, with a small amount of calcite, and some unburned carbon. Hematite, SrSO4 and barite also can be observed in fly ashes by SEM. Typical plerophere occurs in fine fly ash rather than the coarse fly ash. The concentration of most trace elements in CCPs falls within the lower concentration range of European fly ashes. With respect to the partitioning behavior of trace elements during coal combustion, S is highly volatile, and Mg, Na, Zn, B, Co, As, Nb, Zr, Cu and K also show certain volatility, which may to some extent emit to the atmosphere. Furthermore, leaching experiments show that leachable concentrations of most of the potentially toxic elements in CCPs are low, and the CCPs fall in the range between inert and nonhazardous landfill material regulated by the 2003/33/EC Decision.

scholarly journals Preparation of Synthetic Zeolites from Coal Fly Ash by Hydrothermal Synthesis

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1267
Author(s):  
David Längauer ◽  
Vladimír Čablík ◽  
Slavomír Hredzák ◽  
Anton Zubrik ◽  
Marek Matik ◽  
...  
Keyword(s):  
Fly Ash ◽  
Coal Combustion ◽  
Power Plants ◽  
Coal Fly Ash ◽  
Thermal Power ◽  
Product Analysis ◽  
Coal Combustion Products ◽  
X Ray ◽  
Wide Range ◽  
Silica Alumina

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.

scholarly journals Characterization of Fly Ash Generated from Matla Power Station in Mpumalanga, South Africa

2012 ◽  
Vol 9 (4) ◽  
pp. 1788-1795 ◽  
Author(s):  
Olushola S. Ayanda ◽  
Olalekan S. Fatoki ◽  
Folahan A. Adekola ◽  
Bhekumusa J. Ximba
Keyword(s):  
Fly Ash ◽  
Inductively Coupled Plasma ◽  
Coal Fly Ash ◽  
Harmful Effect ◽  
Point Of Zero Charge ◽  
X Ray Diffraction ◽  
Power Station ◽  
X Ray ◽  
Inductively Coupled ◽  
Plasma Mass Spectrometry

In this study, fly ash was obtained from Matla power station and the physicochemical properties investigated. The fly ash was characterized by x-ray fluorescence, x-ray diffraction, scanning electron microscopy, and inductively coupled plasma mass spectrometry. Surface area, particle size, ash and carbon contents, pH, and point of zero charge were also measured. The results showed that the fly ash is alkaline and consists mainly of mullite (Al6Si2O13) and quartz (SiO2). Highly toxic metals As, Sb, Cd, Cr, and Pb as well as metals that are essential to health in trace amounts were also present. The storage and disposal of coal fly ash can thus lead to the release of leached metals into soils, surface and ground waters, find way into the ecological systems and then cause harmful effect to man and its environments.

Mass Absorption Corrected X-ray Diffraction Analysis of Entrained-Flow Reactor Coal Combustion Products

1990 ◽  
Vol 34 ◽  
pp. 429-435
Author(s):  
Leo W. Collins ◽  
David L. Wertz
Keyword(s):  
Coal Combustion ◽  
Initial Phase ◽  
Flow Reactor ◽  
Combustion Process ◽  
Combustion Products ◽  
X Ray Diffraction ◽  
Coal Combustion Products ◽  
X Ray ◽  
Entrained Flow ◽  
Entrained Flow Reactor

AbstractThe analysis of coal and the understanding of the combustion process is complex, due to the heterogeneous nature of the material and the myriad of high-temperature reactions inherent in this fossil fuel. The research presented below utilizes recently-developed x-ray diffraction methods to analyze the coal combustion products generated from a laboratory-scale entrained-flow reactor. The reactor was designed, constructed, and tested, as planned for the initial phase of a long-term project to evaluate the coals located in Mississippi. In this initial phase a well-characterized coal was used, supplied by The Pennsylvania State University. The proximate, ultimate, and sulfur analyses of the coal, PSOC 1368p, are outlined in the Appendix. X-ray diffraction techniques have been used In the past to characterize coals. An analysis of the mineral transformation during coal combustion has also been performed using x-ray diffraction instrumentation. The semi-quantitative results of the pyrite (FeS2) phase transformation at variable temperatures and the percent combustion of the coal, as determined by x-ray methods are reported below.

scholarly journals Treatment of fly ash from power plants using thermal plasma

2017 ◽  
Vol 8 ◽  
pp. 1043-1048 ◽  
Author(s):  
Sulaiman Al-Mayman ◽  
Ibrahim AlShunaifi ◽  
Abdullah Albeladi ◽  
Imed Ghiloufi ◽  
Saud Binjuwair
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fly Ash ◽  
Thermal Plasma ◽  
Inductively Coupled Plasma ◽  
Power Plants ◽  
Plasma Reactor ◽  
Atomic Emission ◽  
Inductively Coupled ◽  
Scanning Electron

Fly ash from power plants is very toxic because it contains heavy metals. In this study fly ash was treated with a thermal plasma. Before their treatment, the fly ash was analyzed by many technics such as X-ray fluorescence, CHN elemental analysis, inductively coupled plasma atomic emission spectroscopy and scanning electron microscopy. With these technics, the composition, the chemical and physical proprieties of fly ash are determined. The results obtained by these analysis show that fly ash is mainly composed of carbon, and it contains also sulfur and metals such as V, Ca, Mg, Na, Fe, Ni, and Rh. The scanning electron microscopy analysis shows that fly ash particles are porous and have very irregular shapes with particle sizes of 20–50 μm. The treatment of fly ash was carried out in a plasma reactor and in two steps. In the first step, fly ash was treated in a pyrolysis/combustion plasma system to reduce the fraction of carbon. In the second step, the product obtained by the combustion of fly ash was vitrified in a plasma furnace. The leaching results show that the fly ash was detoxified by plasma vitrification and the produced slag is amorphous and glassy.

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