Method and theory for optimising ash-fusion characteristics in high-aluminium coal ash via coal blending technology

doi:10.1016/j.cjche.2025.02.037

中国化学工程学报 ›› 2025, Vol. 83 ›› Issue (7): 254-265.DOI: 10.1016/j.cjche.2025.02.037

Method and theory for optimising ash-fusion characteristics in high-aluminium coal ash via coal blending technology

Baoliang Xia¹, Lirui Mao¹, Hanxu Li¹, Chengli Wu¹, Facun Jiao^1,2

1 School of Chemical and Blasting Engineering, Anhui University of Science and Technology, Huainan 232001, China;
2 Anhui Provincial Institute of Modern Coal Processing Technology, Anhui University of Science and Technology Huainan 232001, China

收稿日期:2024-11-12 修回日期:2024-12-18 接受日期:2025-02-19 出版日期:2025-07-28 发布日期:2025-07-28
通讯作者: Lirui Mao,E-mail:maolirui123@163.com;Facun Jiao,E-mail:fcjiao@aust.edu.cn
基金资助:
The completion of this work and related results received support from the National Natural Science Foundation of China (22408004), the Scientific Research Foundation for the Introduction of Talent, Anhui University of Science and Technology (2023yjrc90), the Fundamental Research Funds of the AUST (2024JBQN0015), and the Open Research Fund Program of Anhui Provincial Institute of Modern Coal Processing Technology, Anhui University of Science and Technology (MTY202302).

Method and theory for optimising ash-fusion characteristics in high-aluminium coal ash via coal blending technology

Baoliang Xia¹, Lirui Mao¹, Hanxu Li¹, Chengli Wu¹, Facun Jiao^1,2

1 School of Chemical and Blasting Engineering, Anhui University of Science and Technology, Huainan 232001, China;
2 Anhui Provincial Institute of Modern Coal Processing Technology, Anhui University of Science and Technology Huainan 232001, China

Received:2024-11-12 Revised:2024-12-18 Accepted:2025-02-19 Online:2025-07-28 Published:2025-07-28
Contact: Lirui Mao,E-mail:maolirui123@163.com;Facun Jiao,E-mail:fcjiao@aust.edu.cn
Supported by:
The completion of this work and related results received support from the National Natural Science Foundation of China (22408004), the Scientific Research Foundation for the Introduction of Talent, Anhui University of Science and Technology (2023yjrc90), the Fundamental Research Funds of the AUST (2024JBQN0015), and the Open Research Fund Program of Anhui Provincial Institute of Modern Coal Processing Technology, Anhui University of Science and Technology (MTY202302).

摘要/Abstract

摘要： China has abundant resources of high-alumina coal (HAC). However, its application as a raw gasification material is limited owing to high ash-fusion characteristics. For overcoming the limitation, this study employed Xinjiang coal (XJ), having a low ash fusion temperature, to improve the ash fusibility and viscosity of high-alumina Jungar coal (JG). The evolution of Al-containing phases and structures during mixed ash melting were investigated based on XRD, XPS, ²⁷Al NMR, high-temperature stage microscopy (HTSM), and thermodynamic simulations. An increase in the XJ mass ratio resulted in the transformation of gehlenite to anorthite and mullite, producing more amorphous materials at high temperature. These phenomena were manifested at a microscopic imaging as an increase in the number of reaction/melting sites and their area expansion rate, as well as a decrease in ash area shrinkage and melting temperature. Moreover, the introduction of XJ altered the aluminaeoxygen network, reducing the binding to the silicaoxygen network and converting some [AlO₆]^9- to [AlO₄]^5- as the relative concentration of O_2- and O^- increases. Consequently, the decrease in the stability of the aluminate structure improves the AFT and viscosity. Based on these results, a mechanism to improve the ash fusion characteristics of HAC based on coal blending is proposed.

关键词: High-aluminium coals, Ash-fusion characteristics, Coal blending, Solid-liquid transformation, Situ melting process, Aluminosilicate structural

Abstract: China has abundant resources of high-alumina coal (HAC). However, its application as a raw gasification material is limited owing to high ash-fusion characteristics. For overcoming the limitation, this study employed Xinjiang coal (XJ), having a low ash fusion temperature, to improve the ash fusibility and viscosity of high-alumina Jungar coal (JG). The evolution of Al-containing phases and structures during mixed ash melting were investigated based on XRD, XPS, ²⁷Al NMR, high-temperature stage microscopy (HTSM), and thermodynamic simulations. An increase in the XJ mass ratio resulted in the transformation of gehlenite to anorthite and mullite, producing more amorphous materials at high temperature. These phenomena were manifested at a microscopic imaging as an increase in the number of reaction/melting sites and their area expansion rate, as well as a decrease in ash area shrinkage and melting temperature. Moreover, the introduction of XJ altered the aluminaeoxygen network, reducing the binding to the silicaoxygen network and converting some [AlO₆]^9- to [AlO₄]^5- as the relative concentration of O_2- and O^- increases. Consequently, the decrease in the stability of the aluminate structure improves the AFT and viscosity. Based on these results, a mechanism to improve the ash fusion characteristics of HAC based on coal blending is proposed.

Key words: High-aluminium coals, Ash-fusion characteristics, Coal blending, Solid-liquid transformation, Situ melting process, Aluminosilicate structural

Baoliang Xia, Lirui Mao, Hanxu Li, Chengli Wu, Facun Jiao. Method and theory for optimising ash-fusion characteristics in high-aluminium coal ash via coal blending technology[J]. 中国化学工程学报, 2025, 83(7): 254-265.

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Method and theory for optimising ash-fusion characteristics in high-aluminium coal ash via coal blending technology

Method and theory for optimising ash-fusion characteristics in high-aluminium coal ash via coal blending technology

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