晋城粉煤煤灰不均匀熔融规律研究

提出了煤灰不均匀熔融概念，有助于解决灰熔融性测定结果和锅炉实际情况不符的问题。采用山西晋城煤，将其粉磨到工业煤粉细度，通过浮沉分成不同密度级别子样，使用灰锥法测定其在弱还原气氛下的熔融温度，使用压降法测量其烧结温度，采用XRD、XRF、SEM-EDX等分析手段对灰样的不均匀熔融现象进行机理研究。结果表明，晋城煤灰软化温度为1501℃，而不同密度级别子样发生分化，软化温度从1292℃到高于1600℃变化；同样，晋煤煤灰烧结温度为885℃，子样的烧结温度从833到943℃变化。机理研究表明，不同密度级别子样Al₂O₃、Fe₂O₃和SO₃含量发生不均匀分布，是造成煤灰熔融特性和烧结特性差异的根本原因。

Research on the uneven ash melting behavior of pulverized Jincheng coal

According to the contradiction between ash melting theory and practice, an uneven melting theory was proposed. A typical Jincheng coal from Shanxi, China, was selected, which was ground into the particle size similar to the industrial use. It was separated into different density fractions through float and sink tests, and its chemical composition and mineral composition were analyzed with XRF and XRD, respectively. Ash fusion temperatures (AFTs) under light reducing atmosphere and the pressure-drop temperature(PDT) were tested. SEM-EDX was also employed to observe the melting behavior. It is found that the softening temperature of Jincheng coal is 1501℃, while that of its density fractions changes from 1292℃ to 1600℃. The sintering temperature changes from 833℃ to 943℃, while that of the raw coal ash was 885℃. The study of mechanism shows that the difference of melting and sintering behaviors is caused by the segregation of chemical composition in different density samples, mainly Al₂O₃, Fe₂O₃ and SO₃.