摘要
近年来,污泥、生活垃圾作为水泥生产的部分燃料应用于水泥生产,造成水泥窑炉衬材料硅莫砖的严重碱侵蚀破坏和剥落,影响水泥窑的稳定运行。采用碱蒸气法系统研究了水泥窑硅莫砖用高铝矾土、莫来石(M60)及莫来凯特3种铝硅系耐火原料抗碱蒸气侵蚀行为。结果表明:3种铝硅系耐火原料的碱蒸气侵蚀行为,与原料中的化学成分、玻璃相含量和成分及其显微结构等密切相关。对于以刚玉、莫来石为主的高铝矾土,碱与刚玉、莫来石晶相发生反应形成钾霞石,产生体积膨胀,使得高铝矾土表面先发生疏松和开裂,后碱蒸气渗入颗粒内部,造成严重碱侵蚀破坏;而对于以莫来石为主的莫来石(M60)原料,碱与莫来石和玻璃相发生反应,形成瞬间液相并析出白榴石相,形成的液相阻止了碱的渗透,使碱侵蚀仅发生在表面层而表现出优良的抗碱侵蚀性能。而莫来凯特原料中晶相莫来石与玻璃相含量相当,玻璃相含量高达46%,其与碱蒸气发生化学反应形成更多的液相,同时析出白榴石相,因氧化钾反应溶解在该原料玻璃相中,造成原料整体性侵蚀破坏。
Sewage sludge and household garbage are used as an alternative fuel in recent production of cement.However,the alternative fuel causes serious alkali attack and spalling of bauxite-SiC refractories for cement kiln lining,thus having an impact on the operation of the cement kiln.In this paper,the alkali vapor exposure was used to evaluate alkali attack on some raw materials like bauxite,mullite(M60)and molochite,which were used to prepare mullite-SiC composite refractory as a lining of cement kiln.The results show that the alkali attack resistance of these raw materials is closely related to their chemical composition,phase composition and microstructures.Bauxite with corundum and mullite as main phases is attacked by alkali to form a kaliophilite phase and induce cracks and loose structure,further enhancing gaseous alkali penetration and serious damage.Mullite(M60)with mullite as a main phase is attacked by alkali to form leucite and transient liquid phase.The resultant liquid phase prevents from the penetration of alkali,and the attack only occurs on the surface layer,so mullite(M60)exhibits a superior alkali attack resistance.Molochite with mullite and glass(the content of 46%)reacts with alkali vapor to form more liquid phase and leucite.As alkali vapor is dissolved in the glass phase of molochilte,the integrity of molochite is destroyed by alkali attack.
作者
王治峰
李亚伟
徐义彪
桑绍柏
马淑龙
张海波
高长贺
WANG Zhifeng;LI Yawei;XU Yibiao;SANG Shaobai;MA Shulong;ZHANG Haibo;GAO Changhe(The State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,China;Beijing Jinyu Tongda Refractory Technologies Ltd.,Beijing 100085,China)
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2022年第6期1694-1700,共7页
Journal of The Chinese Ceramic Society
基金
大宗铝硅酸盐无机固废物相重构与转化利用科学基础(2019YFC1904900)
轻量耐火材料微结构设计、调控及其性能研究(2019CFA050)。
关键词
铝硅系耐火原料
氧化铝
氧化硅
碱蒸气
侵蚀行为
alumina-silica refractory raw materials
alumina
silica
alkali vapor
alkali attack behavior
