模拟氢基竖炉工况条件下铝硅质耐火材料的结构与性能演变  

Structural and properties Evolution of Al_(2)O_(3)-SiO_(2) Refractories under Simulated Hydrogen-Based Shaft Furnace Condition

作　　者：颉付博 李亚伟[1,2] 廖宁[1,2] 史成龙 蔡国庆 秦建涛 XIE Fubo;LI Yawei;LIAO Ning;SHI Chenglong;CAI Guoqing;QIN Jiantao(The State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,China;National-Provincial Joint Engineering Research Center of High Temperature Materials and Lining Technology,Wuhan University of Science and Technology,Wuhan 430081,China;Shandong Refractories Group Lunai Kiln Co.,Ltd.,Zibo 255200,China)

机构地区：[1]武汉科技大学省部共建耐火材料与冶金国家重点实验室,武汉430081 [2]武汉科技大学高温材料与炉衬技术国家地方联合工程研究中心,武汉430081 [3]山东耐材集团鲁耐窑业有限公司,淄博255200

出　　处：《硅酸盐通报》2024年第3期1133-1142,共10页Bulletin of the Chinese Ceramic Society

基　　金：湖北省重点研发计划(2023BCB100);青海省自然科学基金面上项目(2022-ZJ-928)。

摘　　要：基于H_(2)/CO混合气强还原服役环境,本工作模拟常压氢基竖炉服役工况,研究典型的铝硅质耐火材料经还原处理后性能变化规律及失稳机制。结果表明,在V(H_(2))∶V(CO)=5∶2的条件下,热处理温度由450℃升高至950℃,混合气体对铝硅质耐火材料的还原能力逐渐增强。现有条件下,铝硅质耐火材料失稳的两个关键因素在于Fe_(2)O_(3)含量以及磷酸盐结合剂:1)当铝硅质耐火材料中Fe_(2)O_(3)含量较高时,在H_(2)/CO气氛下,Fe_(2)O_(3)极易被还原为单质铁。同时,这种情况会导致铝硅质耐火材料发生一定程度的体积变化和显著的力学性能下降。2)磷酸盐结合铝硅质耐火材料也面临磷酸盐挥发,导致显气孔率提高,结构稳定性降低。然而,研究还发现磷酸盐结合刚玉-莫来石砖中Fe_(2)O_(3)含量较低且伴生一定含量的TiO_(2)时,材料具有较好的抗H_(2)/CO气还原能力。通过比较铝硅质耐火材料在CO气氛和H_(2)/CO气氛下力学性能,发现V(H_(2))∶V(CO)=5∶2气氛下在850℃热处理3 h比CO气氛下500℃热处理100 h具有更强的还原能力。Currently,research on hydrogen-based shaft furnaces mainly focuses on the reduction thermodynamics and kinetic processes and furnace structure design,while research on refractories is rare.Based on the strong reducing environment of H_(2)/CO mixed gas,this study simulated the service conditions of atmospheric pressure hydrogen-based shaft furnaces,and researched the performance changes and instability mechanisms of typical Al_(2)O_(3)-SiO_(2) refractories after reduction treatment.The results show that under the condition of V(H_(2))∶V(CO)=5∶2,the heat treatment temperature rises from 450℃ to 950℃,and the reduction ability of mixed gas to Al_(2)O_(3)-SiO_(2) refractories is gradually enhanced.Under current conditions,the two key factors leading to the instability of Al_(2)O_(3)-SiO_(2) refractories are the Fe_(2)O_(3) content and the phosphate binder.1)When the Fe_(2)O_(3) content in Al_(2)O_(3)-SiO_(2) refractories is high,it is easily reduced to elemental iron in the H_(2)/CO atmosphere.At the same time,this situation will lead to a certain degree of volume change and significant decrease in mechanical properties of Al_(2)O_(3)-SiO_(2) refractories.2)Phosphate-bonded Al_(2)O_(3)-SiO_(2) refractories materials also face phosphate volatilization,leading to an increase of apparent porosity and a decrease in structural stability.However,it is found that when the Fe_(2)O_(3) content in the phosphate-bonded alumina-mullite brick is lower and accompanied by a certain amount of TiO_(2),the refractories exhibits good resistance to H_(2)/CO gas reduction.By comparing the mechanical properties of Al_(2)O_(3)-SiO_(2) refractories in CO atmosphere and H_(2)/CO atmosphere,it is found that the heat treatment condition which holding 3 h at 850℃ in the atmosphere of V(H_(2))∶V(CO)=5∶2 has a stronger reducing ability than the heat treatment condition which holding 100 h at 500℃ in CO atmosphere.

关 键 词：氢基竖炉 H_(2)/CO气氛 铝硅质耐火材料 Fe_(2)O_(3) 磷酸盐 CO气氛 

分 类 号：TQ175[化学工程—硅酸盐工业]