Size-related variations in coal fly ash composition as determined using automated scanning electron microscopy

Katrinak, Karen A.; Zygarlicke, Christopher J.

doi:10.1016/0378-3820(95)00019-4

Cited by 20 publications

(9 citation statements)

References 3 publications

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“…Analytical electron microscopy (AEM) is one of the most versatile tools for obtaining information about individual particles. The morphology, size and composition of micrometre and even submicrometre coal fly ash particles have been well characterized by a variety of electron microscopy techniques, including conventional scanning electron microscopy (SEM) (Quann & Sarofim, 1986; Seames, 2003), computer‐controlled scanning electron microscopy (CCSEM) (Huffman et al ., 1989, 1990; Katrinak & Zygarlicke, 1995; O’Keefe et al ., 2000; Chen et al ., 2004), and conventional transmission electron microscopy (TEM) (Azar & Thomas, 1988; Qian et al ., 1988; Hurley & Schobert, 1992; Vassilev & Vassileva, 1996). However, scant information is available on ultrafine (< 100 nm) particles, which are abundant in coal fly ash PM 2.5 samples.…”

Section: Introductionmentioning

confidence: 99%

Characterization of ultrafine coal fly ash particles by energy‐filtered TEM

Chen

Shah

Huggins

et al. 2005

Journal of Microscopy

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SummaryIn this study, energy-filtered transmission electron microscopy is demonstrated to be a valuable tool for characterizing ultrafine coal fly ash particles, especially those particles encapsulated in or associated with carbon. By examining a series of elemental maps (K-edge maps of C and O, and L-edge maps of Si, Al, Ti and Fe) recorded using the three-window method, considerable numbers of titanium and iron species with sizes from several nanometres to submicrometre were shown to be present, typically as oxides dispersed in the carbonaceous matrix. Crystalline phases, such as rutile and iron-rich oxide spinel, were also identified from electron diffraction patterns and highresolution TEM images. Information about these ultrafine coal fly ash particles regarding their size, morphology, elemental composition and distribution, and crystalline phases, which has not been available previously in conventional ash studies, should be useful in toxicological studies and related environmental fields.

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Section: Introductionmentioning

confidence: 99%

Characterization of ultrafine coal fly ash particles by energy‐filtered TEM

Chen

Shah

Huggins

et al. 2005

Journal of Microscopy

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“…According to the relative contents of the above-listed elements, the inorganic particles were classified into one of 33 user-specified mineral categories, while the particles not matching any of the prescribed categories were considered as "unclassified", which has a complex elemental composition and is difficult to be classified. The mineral categories and their elemental composition criteria were developed by Huggins et al [23] and Zygarlicke et al, [24] and had been adopted by others broadly [15,25,26]. The basic feature data of each particle involving its area, perimeter, circularity, X and Y coordinates, elemental distribution, etc., were stored in files to be offline processed.…”

Section: Ccsem Analysis Term and Criterionmentioning

confidence: 99%

The melting potential of various ash components generated from coal combustion: Indicated by the circularity of individual particles using CCSEM technology

Wen

Zhou

et al. 2015

Fuel Processing Technology

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“…The particle size and elemental composition of individual ash particles were analyzed by CCSEM (SEM, JSM-6510; EDS, EDAX126 GENESIS). Ash mineral species were classified according to the previous research. − The details of CCSEM analysis procedures can be found in our previous work …”

Section: Experimental Sectionmentioning

confidence: 99%

Impact of Oxy-fuel Combustion on Ash Properties and Sintering Strength Development

Liu

et al. 2018

Energy Fuels

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For a successful implementation of the oxy-fuel combustion technology, a good understanding of ash-related issues has to be achieved. Knowledge is still lacking on how oxy-fuel combustion can affect ash properties and its sintering behavior. These are the focus of the present work. Combustion experiments of a sub-bituminous coal were carried out in a drop-tube furnace at 1573 K and under air and different oxy-fuel conditions (i.e., OXY21, 21 vol % O2/79 vol % CO2; OXY27, 27 vol % O2/73 vol % CO2; and OXY32, 32 vol % O2/68 vol % CO2). The bulk ash samples were collected and subjected to analyses by techniques such as computer-controlled scanning electron microscopy, X-ray diffraction, and scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy. Sintering tests of the bulk ashes were performed at temperatures ranging from 1023 to 1223 K. The compressive strength of sintered ash was characterized. The results show that oxy-fuel combustion has significant impacts on ash speciation rather than its elemental composition. Ash particle size distributions are also affected, which is mainly attributed to changes in char burning temperatures. Oxy-fuel combustion seems to have insignificant effects on the temperature at which the ash pellet starts to sinter but apparently affects the ash sintering strength. In comparison to the ash from air combustion (AIR ash), the OXY21 ash has a much higher sintering strength. Nevertheless, a decrease of the sintering strength is observed for the OXY27 and OXY32 ashes compared to the OXY21 ash. Such differences are attributed to changes in ash chemical properties.

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Size-related variations in coal fly ash composition as determined using automated scanning electron microscopy

Cited by 20 publications

References 3 publications

Characterization of ultrafine coal fly ash particles by energy‐filtered TEM

Characterization of ultrafine coal fly ash particles by energy‐filtered TEM

The melting potential of various ash components generated from coal combustion: Indicated by the circularity of individual particles using CCSEM technology

Impact of Oxy-fuel Combustion on Ash Properties and Sintering Strength Development

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