低比重分煤中结渣相关矿物质分布的实验研究

Experimental Study on Distribution of Mineral Matter Relating to Slagging in Light Coal Fractions

对结渣特性差异大的神华煤和山西贫煤比重分离制取低比重分煤,使用ICP-AES、XRD和穆斯堡尔谱分析低比重分煤及其原煤盐酸分离前后的样品,对比研究低比重分煤及其原煤中结渣相关矿物质,特别是黏土矿物分布。结果表明神华煤低比重分煤中钙主要为有机钙,铁基本以黄铁矿存在,并且该黄铁矿大部分溶于盐酸。煤燃烧时这些含铁、钙物质和黏土矿物的作用产物应该对该煤种的易结渣性具有重要贡献。两种动力煤的低比重分煤中黏土矿物种类和相对分布均与原煤中相同,并且黏土矿物在低比重分煤成灰物质中的份额均高于在原煤中的份额,针对黏土矿物在煤粉燃烧过程中的热反应产物的研究将为理解飞灰中易熔融物质的形成机理提供更深入的认识。

Light （low density） fractions of Shenhua coal and Wuxiang coal（Shanxi lean coal） were prepared. The two coals are different in slagging characteristics. Samples of the light coal fractions and their raw coals before and after an HCl separation were analyzed using ICP-AES, X-ray diffraction and Mossbauer spectroscopy. The distribution of mineral matter relating to slagging characteristics, especially clay minerals, in the light coal fractions were investigated by comparison. The results show that in the Shenhua light coal fraction, the calcium was mainly organically bounding calcium, and the iron existed basically in form of pyrite. The pyrite could be dissolved in hydroehloride acid. The products of interaction of the matter containing iron or calcium with the clay minerals during coal combustion should make important contributions to the occurrence of slagging of this steam coal. With these two steam coals, the species and relative contents of clay minerals in the light coal fractions were same with those in their respective raw coals. The contents of clay minerals in the mineral matter of the light coal fractions were both higher than those in the mineral matter of their respective raw coals. The study on the thermal reaction products of clay minerals in light coal fractions may provide new insights into the production mechanisms for easily-formed slagging material in the ash from light coal fractions.