Corrosion behavior of co-gasification slag of furfural residue and coal on alumina-silica refractories
MA Xiaotong;WANG Zhigang;LU Hao;LIU Wei;WANG Yanxia;ZHAO Jiangshan;SUN Lingmin;YAN Jingchong;ZHUANG Shujuan;LI Huaizhu;KONG Lingxue
德州学院 化学化工学院山东理工大学 化学化工学院中国科学院山西煤炭化学研究所 煤炭高效低碳利用全国重点实验室安徽工业大学 化学与化学工程学院
糠醛渣与煤共气化是实现其清洁高效利用的可行路径,但煤中配入碱金属含量高的糠醛渣易造成气化炉耐火材料的腐蚀。本研究选用两种不同硅铝比(Si/Al)的气化煤和一种糠醛渣,利用X射线衍射仪(XRD)、扫描电镜(SEM-EDS)和Factsage热力学计算软件研究了配入糠醛渣的共气化灰渣对硅砖、刚玉砖、高铝砖和莫来石砖四种硅铝质耐火材料侵蚀的影响,分析了灰渣侵蚀耐火材料的机理。随着糠醛渣配比的增加,共气化灰渣对刚玉砖、高铝砖和莫来石砖三种铝质耐火材料的渗透率均呈先降低后增加的趋势,硅砖的渗透率呈逐渐降低的趋势。配入糠醛渣的灰渣中K2O、SiO2与铝质耐火材料中Al2O3反应生成的难熔矿物质白榴石(KAlSi2O6),阻碍灰渣在耐火材料的渗透。随着糠醛渣配比的增加,灰渣中K2O含量增加,形成低熔点矿物质钾霞石(KAlSiO4),加剧了灰渣在耐火材料的渗透。灰渣与硅砖间发生明显的矿物酸碱反应,随着糠醛渣配比的增加,更多的灰渣与硅砖中SiO2在表面发生反应,渗入硅砖内的灰渣量降低。硅砖的侵蚀主要由矿物酸碱反应引起,而铝质耐火材料的腐蚀主要由灰渣渗透决定的。氧化铝为主的耐火材料的渗透率能与灰渣黏度建立线性关系,其渗透率随灰渣黏度的降低而增加,这也导致低黏度的高Si/Al渣比高黏度的低Si/Al比渣表现出更强的渗透性。
Gasification of furfural residue with coal can realize its efficient and clean utilization. But the high alkali metal content in furfural slag is easy to cause the corrosion of gasifier refractory. Two gasification coals with different silica alumina ratio and a furfural residue were selected in the study. The effects of furfural residue additions on corrosion of silica brick, corundum brick, high alumina brick and mullite brick were investigated by using XRD, SEM-EDS and Factsage Software, and the corrosion mechanism was analyzed. With increasing furfural residue addition, the permeability of the slags to high-aluminium-bearing refractories first decreases and then increases, while the permeability on silica brick shows a slight decrease trend. Leucite (KAlSi2O6) with high-melting temperature is generated from the reaction of K2O and SiO2 in slag with Al2O3 in refractories after furfural residue is added, which hinders the infiltration of slag in refractories. Kaliophilite (KAlSiO4) of low-melting point is formed when K2O content increases, and this contributes to the infiltration of slag in refractories. The acid-base reaction between slag and silica brick is distinctly occurred, more slag reacts with SiO2 in the silicon brick, resulting in a decrease in the amount of slag infiltrating into the silicon brick as furfural residue is added. The corrosion of silica brick is mainly caused by the acid-base reaction, while the corrosion of three alumina based refractory bricks of corundum, mullite and high alumina brick is determined by slag infiltration. A linear correlation between the percolation rate and slag viscosity is established, the slag permeability increases with decreasing viscosity, resulting in stronger permeability for the high Si/Al ratio slag with lower viscosity.
furfural residue;co-gasification;slag;refractory;corrosion
主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会