模拟煤气化炉气氛下酸性渣对Si3N4–SiC材料的侵蚀及其机理  

Erosion Mechanism of Si3N4 Bonded SiC Materials by Acid Coal Slag in Simulated Atmosphere of Coal Gasifier

作　　者：蔡斌利[1] 李红霞[1,2] 赵世贤[2] 孙红刚[2] 李鹏涛[2] 闫双志[2] 万龙刚[2] 王刚[2] 曹战民[3] CAI Binli1, LI Hongxia 1,2, ZHAO Shixian2, SUN Honggang2, LI Pengtao2, YAN Shuangzhi2, WAN Longgang2, WANG Gang2, CAO Zhanmin3(1. School of Materials Science and Engineering, University of Science ＆ Technology Beij ing, B eij ing 100083, China 2. State Key Laboratory of Advanced Refractories, Sinosteel Luoyang Institute of Refractories Research Co., Ltd., Luoyang 471039, Henan, China; 3. School of Metallurgical and Ecological Engineering, University of Science ＆ Technology Beijing, Beijing 100083, Chin)

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]中钢集团洛阳耐火材料研究院有限公司先进耐火材料国家重点实验室,河南洛阳471039 [3]北京科技大学冶金与生态工程学院,北京100083

出　　处：《硅酸盐学报》2018年第3期434-442,共9页Journal of The Chinese Ceramic Society

基　　金：NSFC–河南联合基金重点支持项目(U1604252)资助

摘　　要：在回转抗渣炉内模拟气化炉1 500℃时的工作环境,进行熔渣对Si3N4结合SiC试样的动态侵蚀实验,利用扫描电镜观察侵蚀后试样的显微结构,并结合热力学模拟研究酸性煤渣对Si3N4–SiC材料的侵蚀机理。结果表明：实验条件下,熔渣中的FeO与Si3N4–SiC材料发生氧化还原反应,在试样表面形成C、Si、Fe合金;Si3N4–SiC试样发生活性氧化,形成气体和方石英,且方石英向熔渣中溶解;氧化反应改变了试样中气孔表面的结构组成,熔渣通过气孔向试样中渗透,在试样表面形成很薄的反应层。反应层的形成加剧了熔渣向试样中的渗透及试样向熔渣中的溶解。因此,Si3N4–SiC材料不适合用做水煤浆气化炉内衬材料。The dynamic erosion experiments of Si3N4 bonded SiC samples interacted with acid coal slag were conducted in an improved rotary drum furnace under slagging gasifier conditions at 1 500 ℃. The erosion mechanism was also investigated by thermal dynamic simulation and scanning electron microscopy. The results show that Si-Fe-C alloy is formed on the surface of the samples under the experimental atmosphere when Si3N4 bonded SiC materials react with FeO. In addition, Si3N4 bonded SiC materials are also oxidized to form gases and cristobalite, which dissolve into molten slag eventually. The oxidation reaction can change the pore structures on the surface, resulting in the slag penetration into the samples through the pores to form a thin reaction layer. The reaction layer eventually aggravates the slag penetration and brick dissolution. Therefore, Si3N4-SiC is not suitable as a lining material of coal-water slurry gasifier.

关 键 词：煤气化炉 还原性气氛 氮化硅结合碳化硅 侵蚀机理 热力学模拟 

分 类 号：TQ175[化学工程—硅酸盐工业]