Effects of basic oxides on ash fusion characteristic of coal ash

被引：0

作者：

Zheng, Ye ^{[1
]}

Li, Jianbo ^{[2
]}

Guan, Yanjun ^{[1
]}

Yang, Fengling ^{[3
]}

Zhang, Kai ^{[1
]}

Cheng, Fangqin ^{[3
]}

机构：

[1] Beijing Key Laboratory of Emission Surveillance and Control for Thermal Power Generation, North China Electric Power University, Beijing,102206, China

[2] Key Laboratory of Low-grade Energy Utilization Technologies and Systems of the Ministry of Education of China, Chongqing University, Chongqing,400044, China

[3] Institute of Resources and Environment Engineering, School of Environmental & Resource Sciences, State Environmental Protection Key Laboratory of Efficient Utilization Technology of Coal Waste Resources, Taiyuan,Shanxi,030006, China

来源：

Huagong Jinzhan/Chemical Industry and Engineering Progress | 2020年 / 39卷 / 02期

关键词：

Aluminum compounds - Calcium compounds - Coal ash - Hematite - Magnesia - Silica - Silicon - X ray diffraction;

D O I：

暂无

中图分类号：

学科分类号：

摘要：

The fusion characteristics of twenty-three synthetic ashes with the same acidic to basic ratio (Ra/b) of 0.82 but with varying acidic oxides including Na2O, CaO, MgO, and Fe2O3 were investigated. The synthetic ashes were prepared in accordance with the Ra/b of Zhundong coal ash, and then ashed in a muffle furnace at 815℃. These ashes were then subjected to ash fusion analyzer, SEM-EDS and XRD analysis for their fusion temperatures (AFTs), microstructures and mineralogical composition. The results showed that deformation temperature (DT), softening temperature (ST), hemispherical temperature (HT) and flow temperature (FT) of the synthetic ash decreased from 1225℃, 1233℃, 1255℃ and 1297℃, respectively, to 1162℃, 1174℃, 1181℃ and 1189℃ as Na2O content increased from 4% to 12%, indicating that Na2O played a significant role in decreasing AFTs. Likewise, as the CaO and MgO contents increased, DT, ST and HT were decreased, while FT was decreased first but increased afterwards, indicating that the effect of CaO and MgO addition on AFTs were non-linear. Furthermore, significant changes in AFTs were not observed as Fe2O3 mass fraction varied from 5% to 30%, with the exception that FT increased from 1215℃ to 1308℃. SEM-EDS and XRD analysis revealed that the variation in fusion characteristics of the synthetic ashes were mainly attributed to the proportion of refractory minerals mainly SiO2 and CaAl2Si2O8 and the fluxing minerals such as CaMgSi2O6 and NaAlSiO4, as well as the degree of eutectic formation between Na- and Ca- bearing minerals. A comprehensive comparison between the measured AFTs and their corresponding basic oxide contents showed that DT was mainly affected by the overall amount of alkaline-earth metal (CaO and MgO) and Na2O content, whereas FT was closely associated with Na2O and Fe2O contents in the synthetic ash. © 2020, Chemical Industry Press. All right reserved.

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页码：496 / 505