Mössbauer Studies of Narrow Fractions of Fly Ash Formed after Combustion of Ekibastuz Coal
Nuclear gamma-resonance spectroscopy on <sup>57</sup>Fe nuclei, X-ray diffraction, and scanning electron microscopy have been used to study the narrow fractions of fly ash formed after combustion of the Ekibastuz coal. Two groups of samples of magnetic (ferrospheres) and non-magnetic typ...
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2021-12-01
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| author | Mikhail Vereshchak Irina Manakova Adilkhan Shokanov Sayabek Sakhiyev |
| author_facet | Mikhail Vereshchak Irina Manakova Adilkhan Shokanov Sayabek Sakhiyev |
| author_sort | Mikhail Vereshchak |
| collection | DOAJ |
| description | Nuclear gamma-resonance spectroscopy on <sup>57</sup>Fe nuclei, X-ray diffraction, and scanning electron microscopy have been used to study the narrow fractions of fly ash formed after combustion of the Ekibastuz coal. Two groups of samples of magnetic (ferrospheres) and non-magnetic type have been separated by granulometric and magnetic separation. A number of regularities associated with the granules size of fly ash have been established. According to the data of Mössbauer spectroscopy, a decrease in the magnetically ordered contribution has been identified with the growth of the particle size. After magnetic separation, iron in ferrospheres was found mainly in the structure of Fe<sub>3</sub>O<sub>4</sub>/γ-Fe<sub>2</sub>O<sub>3</sub> and α-Fe<sub>2</sub>O<sub>3</sub>. The dominant phase was Fe<sub>3</sub>O<sub>4</sub> (60–77%), the amount of which decreases with the growth of the grain size. With the growth of the particle size, the ratio of <i>[Fe]<sup>tetra</sup>/[Fe]<sup>octa</sup></i> positions occupancy in Fe<sub>3</sub>O<sub>4</sub> approaches 0.5; the structure of magnetite tends to the stoichiometric composition. α-Fe was found in the composition of ferrospheres, and a mechanism of its formation was proposed. The main components of the non-magnetic fractions of fly ash are mullite, hercynite, and silicate glass. |
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| format | Article |
| id | doaj.art-8e200a65d9424caa834ed74e567167ee |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-10T04:49:31Z |
| publishDate | 2021-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-8e200a65d9424caa834ed74e567167ee2023-11-23T02:44:03ZengMDPI AGMaterials1996-19442021-12-011423747310.3390/ma14237473Mössbauer Studies of Narrow Fractions of Fly Ash Formed after Combustion of Ekibastuz CoalMikhail Vereshchak0Irina Manakova1Adilkhan Shokanov2Sayabek Sakhiyev3Institute of Nuclear Physics, Ibragimov st. 1, Almaty 050032, KazakhstanInstitute of Nuclear Physics, Ibragimov st. 1, Almaty 050032, KazakhstanInstitute of Mathematics, Physics and Informatics, Abai Kazakh National Pedagogical University, Dostyk Av. 13, Almaty 050010, KazakhstanKazakh National Agrarian Research University, Abai Av. 8, Almaty 050010, KazakhstanNuclear gamma-resonance spectroscopy on <sup>57</sup>Fe nuclei, X-ray diffraction, and scanning electron microscopy have been used to study the narrow fractions of fly ash formed after combustion of the Ekibastuz coal. Two groups of samples of magnetic (ferrospheres) and non-magnetic type have been separated by granulometric and magnetic separation. A number of regularities associated with the granules size of fly ash have been established. According to the data of Mössbauer spectroscopy, a decrease in the magnetically ordered contribution has been identified with the growth of the particle size. After magnetic separation, iron in ferrospheres was found mainly in the structure of Fe<sub>3</sub>O<sub>4</sub>/γ-Fe<sub>2</sub>O<sub>3</sub> and α-Fe<sub>2</sub>O<sub>3</sub>. The dominant phase was Fe<sub>3</sub>O<sub>4</sub> (60–77%), the amount of which decreases with the growth of the grain size. With the growth of the particle size, the ratio of <i>[Fe]<sup>tetra</sup>/[Fe]<sup>octa</sup></i> positions occupancy in Fe<sub>3</sub>O<sub>4</sub> approaches 0.5; the structure of magnetite tends to the stoichiometric composition. α-Fe was found in the composition of ferrospheres, and a mechanism of its formation was proposed. The main components of the non-magnetic fractions of fly ash are mullite, hercynite, and silicate glass.https://www.mdpi.com/1996-1944/14/23/7473Mössbauer spectroscopyfly ashgranulometric and magnetic separation |
| spellingShingle | Mikhail Vereshchak Irina Manakova Adilkhan Shokanov Sayabek Sakhiyev Mössbauer Studies of Narrow Fractions of Fly Ash Formed after Combustion of Ekibastuz Coal Materials Mössbauer spectroscopy fly ash granulometric and magnetic separation |
| title | Mössbauer Studies of Narrow Fractions of Fly Ash Formed after Combustion of Ekibastuz Coal |
| title_full | Mössbauer Studies of Narrow Fractions of Fly Ash Formed after Combustion of Ekibastuz Coal |
| title_fullStr | Mössbauer Studies of Narrow Fractions of Fly Ash Formed after Combustion of Ekibastuz Coal |
| title_full_unstemmed | Mössbauer Studies of Narrow Fractions of Fly Ash Formed after Combustion of Ekibastuz Coal |
| title_short | Mössbauer Studies of Narrow Fractions of Fly Ash Formed after Combustion of Ekibastuz Coal |
| title_sort | mossbauer studies of narrow fractions of fly ash formed after combustion of ekibastuz coal |
| topic | Mössbauer spectroscopy fly ash granulometric and magnetic separation |
| url | https://www.mdpi.com/1996-1944/14/23/7473 |
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