准东煤循环流化床气化过程中的矿物质转化行为特性

摘要

Based on a 0.25,t/d test system of high alkali coal thermochemical conversion,the mineral transforma-tion behavior of Tianchimulei coal was studied during gasification with XRD,SEM-EDX and ICP-AES.The re-sults show that Ca and Na in the forms of CaSO4 and NaCl are rich in Tianchimulei coal,and other elements mostly exist in aluminosilicatie minerals.During gasification,sodium silicate was found to be the main cause for slag agglomeration with eutectic and composite sulfate,which was composed of K,Mg,Fe and Ca,and acted as low temperature flux.Volatile Na is enriched in fly ash particles resulting in contamination of tail heating surface,while rich-Ca floccule with high-melting-point appears in the fly ash.%基于0.25,t/d高碱煤热化学转化热态试验台,利用X射线衍射(XRD)、扫描电镜-X射线能谱(SEM-EDX)和电感耦合等离子体-原子发射光谱(ICP-AES)等手段,研究了准东天池木垒煤在煤气化过程中的矿物质转化行为.结果表明,天池木垒煤中含有大量Ca和Na,且主要分别以CaSO4和NaCl的形式存在,其他矿物质元素多以硅铝酸盐矿物形式存在;在煤气化过程中,Na的硅酸盐是引起底渣聚团的主要原因,K、Mg、Fe、Ca等元素组成的低温共熔体和复合硫酸盐对聚团起低温助熔剂的作用;挥发的Na会在飞灰颗粒表面富集,导致尾部受热面出现积灰沾污现象,同时飞灰中有富Ca絮状物生成.