气氛和化学组成对高铁煤灰熔融特性的影响机理  

Effects of atmosphere and chemical composition on fusion characteristics of high-iron coal ash

作　　者：贺冲 白进[2] 郭晶 孔令学[2] 鲁浩 李怀柱[2] 秦育红 李文[2] HE Chong;BAI Jin;GUO Jing;KONG Lingxue;LU Hao;LI Huaizhu;QIN Yuhong;LI Wen(College of Environmental Science and Engineering,Taiyuan University of Technology,Jinzhong 030600,Shanxi,China;State Key Laboratory of Coal Conversion,Institute of Coal Chemistry,Chinese Academy of Sciences,Taiyuan 030001,Shanxi,China;College of Safety and Emergency Management Engineering,Taiyuan University of Technology,Taiyuan 030024,Shanxi,China)

机构地区：[1]太原理工大学环境科学与工程学院,山西晋中030600 [2]中国科学院山西煤炭化学研究所煤转化国家重点实验室,山西太原030001 [3]太原理工大学安全与应急管理工程学院,山西太原030024

出　　处：《化工学报》2022年第10期4648-4658,共11页CIESC Journal

基　　金：国家自然科学基金项目(22108190)。

摘　　要：采用灰熔点仪、XRD和热力学模拟,研究气氛和化学组成对高铁煤灰熔融特性的影响机理。研究结果表明,灰熔融温度随铁含量、钙含量或硅铝比增加而降低。弱还原气氛下低钙或低硅铝比煤灰熔融存在明显的初始熔融阶段,熔融过程遵循“软化-熔融”机理,而空气气氛下高钙或高硅铝比煤灰熔融过程属于“熔融-溶解”机理。弱还原气氛下铁含量增加显著促进石英和钙长石熔融,空气气氛下钙含量增加促进刚玉和石英熔融或转化为钙基硅铝盐。弱还原气氛下液相含量随硅铝比或铁含量增加而增加,液相黏度随钙含量或铁含量增加而降低,促进熔融传质;空气气氛下低钙或低硅铝比煤灰中铁存在于含铁固溶体,导致液相黏度高或液相含量低,熔融传质受阻。Using ash melting point apparatus,XRD and thermodynamic simulation,the influence mechanism of atmosphere and chemical composition on the melting characteristics of high-speed iron coal ash was studied.The results indicate that the fusion temperature of high-iron coal ash decreases with the increasing iron content,or calcium content,or S/A(the mass ratio of SiO_(2) to Al_(2)O_(3)).Further,the fusion behavior of high calcium or high S/A and high-iron ash under mild reducing atmosphere(MR)follows the“melting-dissolution”mechanism due to the existence of the initial melting stage,while the fusion of low calcium or low S/A and high-iron ash under air belongs to the“softening-melting”mechanism.The iron accelerates the melting of quartz and anorthite under MR,and the calcium promotes the melting of quartz and corundum or transformations of these minerals to the calcium-based aluminosilicates.Under MR,the liquid content increases with the iron content or S/A,and the liquid viscosity decreases with the increasing calcium content or iron content,improving the mass transfer.In contrast,the crystallization of iron-containing solid solutions which were found in the low-calcium or low S/A and high iron ash leads to a higher liquid viscosity or lower liquid content under air,inhibiting the mass transfer of ash melting.

关 键 词：煤灰 气化 熔融特性 结晶 相变 化学组成 气氛 

分 类 号：TQ54[化学工程—煤化学工程]