This paper investigated the effect of the pressures, reaction atmospheres and coal ash species on the ash fusibility with high-pressure thermogravimetric analysis (PTGA) apparatus and X-ray diffraction (XRD) analysis. Each specimen analyzed by XRD was observed for the mineral conversion and formation of new minerals with the pressures under different atmospheres. These results indicate that the pressure restrains the transformation and decomposition of minerals. Many low-temperature minerals are still present under the elevated pressure. The different reaction atmospheres have different effects on the formation of coal ash minerals. Under the N2 atmosphere, the present microcline may decrease the melting temperature of coal ash. And later, it transforms into sanidine at high pressure; thus, the melting temperature of coal ash may increase. Under the CO2 atmosphere, the minerals such as microcline, lomonitite, geothite and illite are still present with the increase in pressure; this may reduce the melting temperature. While under the H2O atmosphere, there are magnetite and anorthoclase, which may produce the low-temperature eutectics decreasing the melting temperature. The coal ash abundance in basic oxides or higher SiO2, Fe2O3, K2O and Na2O has lower melting temperature. While the ash sample with more SiO2 and Al2O3 and less Fe2O3 and basic oxides may lead to higher melting temperature.
Corresponding Author(s):
WANG Qinhui,Email:qhwang@zju.edu.cn
引用本文:
. Experiments on the effect of the pressure on the mineral transformation of coal ash under the different reaction atmosphere[J]. Frontiers of Chemical Engineering in China, 2010, 4(4): 394-399.
Nijie JING, Qinhui WANG, Zhongyang LUO, Tao JIE, Xiaomin LI, Kefa CEN. Experiments on the effect of the pressure on the mineral transformation of coal ash under the different reaction atmosphere. Front Chem Eng Chin, 2010, 4(4): 394-399.
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