Influence of Coal Blending on Ash Fusibility in Reducing Atmosphere

Energies

Mingke Shen¹  Kunzan Qiu¹  Long Zhang²  Zhenyu Huang¹  Zhihua Wang¹  Jianzhong Liu¹ 

[1] State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China; E-Mails:;Laboratory for Thermal Hydraulic and Safety, China Nuclear Power Technology Research Institute, Shenzhen 528026, China; E-Mail:

关键词: coal blending;    ash fusibility;    mineral transformations;    eutectic;   

DOI  :  10.3390/en8064735

来源: mdpi

【 摘 要 】

Coal blending is an effective way to organize and control coal ash fusibility to meet different requirements of Coal-fired power plants. This study investigates three different eutectic processes and explains the mechanism of how coal blending affects ash fusibility. The blended ashes were prepared by hand-mixing two raw coal ashes at five blending ratios, G:D = 10:90 (G10D90), G:D= 20:80 (G20D80), G:D = 30:70 (G30D70), G:D = 40:60 (G40D60), and G:D = 50:50 (G50D50). The samples were heated at 900 °C, 1000 °C, 1100 °C, 1200 °C, and 1300 °C in reducing atmosphere. XRD and SEM/EDX were used to identify mineral transformations and eutectic processes. The eutectic processes were finally simulated with FactSage. Results show that the fusion temperatures of the blended ashes initially decrease and then increase with the blending ratio, a trend that is typical of eutectic melting. Eutectic phenomena are observed in D100, G10D90, and G30D70 in different degrees, which do not appear in G100 and G50D50 for the lack of eutectic reactants. The main eutectic reactants are gehlenite, magnetite, merwinite, and diopside. The FactSage simulation results show that the content discrepancy of merwinite and diopside in the ashes causes the inconsistent eutectic temperatures and eutectic degrees, in turn decrease the fusion temperature of the blended ash and then increase them with the blending ratio.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.