Investigation on combustion performance and ash fusion characteristics of Zhundong coal co-combustion with coal gangue. (15th June 2021)

• Record Type: Journal Article
• Authors: Deng, Shuanghui; Tan, Houzhang; Wei, Bo; Wang, Xuebin; Yang, Fuxin; Xiong, Xiaohe
• Is Part Of: Fuel. Volume 294(2021)
• Publication Date: 2021-06-15
• Subjects: Zhundong coal -- Coal gangue -- Co-combustion -- Blending ratio -- Ash fusion; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2021.120555
• Languages: English
• ISSNs: 0016-2361

Abstract

Highlights: The combustion maximum weight loss rate of the ZC-CG blend increases firstly and then decreases with the increase of CG. 30 wt% CG will be the optimal value for obtaining better combustion performance. The different adding percentages of CG result in different ash fusion characteristics of ZC. The results obtained could predict the fouling and slagging propensities of the ZC-CG ash in a boiler. Abstract: In this study, the combustion characteristics of Zhundong coal (ZC), coal gangue (CG) and the ZC-CG blends with 10, 20, 30, 40 and 50% CG were investigated using a thermogravimetric analysis (TGA). The ash fusion characteristic temperatures and mineral transformation behaviors during the ash melting process were also determined by analytical instruments. The results shows that the maximum weight loss rate of the ZC-CG blend increases at first and then decreases with the increase of CG adding percentage, reaching the maximum at 30% CG, while the corresponding peak temperature firstly decreases and then increases. Adding 30% CG into ZC is an optimal blending ratio for obtaining better combustion performance. The ash fusion temperatures of the ZC–CG ash including DT, ST, HT and FT generally increase firstly and then decrease with the increase of CG adding percentage from 10 to 50% CG, reaching the maximums at 40% CG. Ferric oxide (Fe2 O3 ), calcium sulfate (CaSO4 ) and silicon dioxide (SiO2 ) are the main mineral compounds in the ZC-CG ash. As the adding percentage of CG into ZC increases, the microstructures of the ZC-CG ash become tighter and the particle sizes gradually turn bigger. The results obtained can be used for reference in a large pulverized Zhundong coal boiler burning a blended high ash coal for safety and economy.