煤样不同密度组分中致渣矿物特性的CCSEM研究

CCSEM investigation on slagging minerals in different density ingredients of bituminous coal samples

将一种典型的易结渣烟煤分为低（＆lt;1.3 g·cm-3）、中（1.3～1.6 g·cm-3）、高（＆gt;1.6 g·cm-3）3个密度煤样。利用先进计算机控制扫描电镜（CCSEM）技术对原煤及分密度煤样中的致渣矿物进行了深入研究。结果表明， Na与K在煤中无机矿主要以硅铝酸盐的形式存在；粒径大于22μm的外在（独立于炭基质）黄铁矿、磁黄铁矿主要分布在高密度煤中；未识别矿物（复杂硅铝酸盐）在高密度煤矿物中所占的比例最小，但其中Fe含量为20%～90%的颗粒所占比例最高；不同密度煤样中，内在（与炭基质结合）矿的硅铝比和碱酸比不同，低密度煤中内在矿的碱酸比最大，结渣倾向最严重，而中密度煤内在矿的碱酸比和硅铝比均小于原煤。

A typical bituminous coal that could easily lead to slagging was divided into three ingredients with different density, i.e. low-density （＆lt;1.3 g·cm-3）, medium-density （1.3-1.6 g·cm-3） and high-density （＆gt;1.6 g·cm-3）. Computer controlled scanning electron microscopy （CCSEM） was used to analyze and characterize the slagging minerals in the raw coal and three ingredients. The results showed that Na and K in inorganic minerals of the coal exist as aluminosilicate. Exterior （no bonding） pyrite and pyrrhotite with diameter larger than 22μm were mainly present in the high-density sample. The least proportion of unidentified materials in which there were the most particles containing 20%-90% of Fe component was involved in the high-density sample. The ratios of silicon to aluminum and basic to acidic oxides in bonding minerals were variation for different density samples. There was the highest basic to acidic oxides ratio in the low-density sample, suggesting highest slagging propensity. The ratios of silicon to aluminum and basic to acidic oxides were lower for the medium-density sample than for the raw coal.