Mössbauer and X-ray Studies of Phase Composition of Fly Ashes Formed after Combustion of Ekibastuz Coal (Kazakhstan)
Mössbauer spectroscopy and X-ray diffraction have been used to study samples of fly ashes formed after combustion of coal from the Ekibastuz basin at the thermal power plants TPP-2 and TPP-3 in Almaty (Kazakhstan). It has been established that the fractions of fly ashes contain iron in the form of m...
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MDPI AG
2020-07-01
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| Online Access: | https://www.mdpi.com/2075-4701/10/7/929 |
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| author | Adilkhan Shokanov Mikhail Vereshchak Irina Manakova |
| author_facet | Adilkhan Shokanov Mikhail Vereshchak Irina Manakova |
| author_sort | Adilkhan Shokanov |
| collection | DOAJ |
| description | Mössbauer spectroscopy and X-ray diffraction have been used to study samples of fly ashes formed after combustion of coal from the Ekibastuz basin at the thermal power plants TPP-2 and TPP-3 in Almaty (Kazakhstan). It has been established that the fractions of fly ashes contain iron in the form of magnetite Fe<sub>3</sub>O<sub>4</sub> and hematite α-Fe<sub>2</sub>O<sub>3</sub>. The mixed valence of iron Fe<sup>3+</sup> ↔ Fe<sup>2+</sup> in the octahedral sublattice of magnetite is destroyed by isostructural substitution impurities. Maghemite γ-Fe<sub>2</sub>O<sub>3</sub> is additionally present in the fly ash of TPP-3 as a product of magnetite slow oxidation. It was shown that at T ≥ 1400 °C the proportion of magnetite in fly ashes increases due to decomposition of hematite, maghemite, hercynite and the drop of iron content in mullite. It was concluded that the amount of iron in magnetite is a temperature indicator of fly ashes formation. The parameters of hyperfine interactions have been determined in the iron-containing minerals of fly ashes. It was identified that formation of the fly ashes structure occurs in oxidizing atmosphere, since no traces were revealed of reducing environment effect on the phase composition. |
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| issn | 2075-4701 |
| language | English |
| last_indexed | 2024-03-10T18:33:53Z |
| publishDate | 2020-07-01 |
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| spelling | doaj.art-ce2b802aa7e14f568451b70eeb8ed01a2023-11-20T06:24:53ZengMDPI AGMetals2075-47012020-07-0110792910.3390/met10070929Mössbauer and X-ray Studies of Phase Composition of Fly Ashes Formed after Combustion of Ekibastuz Coal (Kazakhstan)Adilkhan Shokanov0Mikhail Vereshchak1Irina Manakova2Institute of Mathematics, Physics and Informatics, Abai Kazakh National Pedagogical University, Dostyk Av. 13, Almaty 050010, KazakhstanInstitute of Nuclear Physics, Ibragimov st. 1, Almaty 050032, KazakhstanInstitute of Nuclear Physics, Ibragimov st. 1, Almaty 050032, KazakhstanMössbauer spectroscopy and X-ray diffraction have been used to study samples of fly ashes formed after combustion of coal from the Ekibastuz basin at the thermal power plants TPP-2 and TPP-3 in Almaty (Kazakhstan). It has been established that the fractions of fly ashes contain iron in the form of magnetite Fe<sub>3</sub>O<sub>4</sub> and hematite α-Fe<sub>2</sub>O<sub>3</sub>. The mixed valence of iron Fe<sup>3+</sup> ↔ Fe<sup>2+</sup> in the octahedral sublattice of magnetite is destroyed by isostructural substitution impurities. Maghemite γ-Fe<sub>2</sub>O<sub>3</sub> is additionally present in the fly ash of TPP-3 as a product of magnetite slow oxidation. It was shown that at T ≥ 1400 °C the proportion of magnetite in fly ashes increases due to decomposition of hematite, maghemite, hercynite and the drop of iron content in mullite. It was concluded that the amount of iron in magnetite is a temperature indicator of fly ashes formation. The parameters of hyperfine interactions have been determined in the iron-containing minerals of fly ashes. It was identified that formation of the fly ashes structure occurs in oxidizing atmosphere, since no traces were revealed of reducing environment effect on the phase composition.https://www.mdpi.com/2075-4701/10/7/929fly ashMössbauer spectroscopyx-ray diffraction |
| spellingShingle | Adilkhan Shokanov Mikhail Vereshchak Irina Manakova Mössbauer and X-ray Studies of Phase Composition of Fly Ashes Formed after Combustion of Ekibastuz Coal (Kazakhstan) Metals fly ash Mössbauer spectroscopy x-ray diffraction |
| title | Mössbauer and X-ray Studies of Phase Composition of Fly Ashes Formed after Combustion of Ekibastuz Coal (Kazakhstan) |
| title_full | Mössbauer and X-ray Studies of Phase Composition of Fly Ashes Formed after Combustion of Ekibastuz Coal (Kazakhstan) |
| title_fullStr | Mössbauer and X-ray Studies of Phase Composition of Fly Ashes Formed after Combustion of Ekibastuz Coal (Kazakhstan) |
| title_full_unstemmed | Mössbauer and X-ray Studies of Phase Composition of Fly Ashes Formed after Combustion of Ekibastuz Coal (Kazakhstan) |
| title_short | Mössbauer and X-ray Studies of Phase Composition of Fly Ashes Formed after Combustion of Ekibastuz Coal (Kazakhstan) |
| title_sort | mossbauer and x ray studies of phase composition of fly ashes formed after combustion of ekibastuz coal kazakhstan |
| topic | fly ash Mössbauer spectroscopy x-ray diffraction |
| url | https://www.mdpi.com/2075-4701/10/7/929 |
| work_keys_str_mv | AT adilkhanshokanov mossbauerandxraystudiesofphasecompositionofflyashesformedaftercombustionofekibastuzcoalkazakhstan AT mikhailvereshchak mossbauerandxraystudiesofphasecompositionofflyashesformedaftercombustionofekibastuzcoalkazakhstan AT irinamanakova mossbauerandxraystudiesofphasecompositionofflyashesformedaftercombustionofekibastuzcoalkazakhstan |