Abstract: SiC assembled large blocks for blast furnace tuyere were prepared using silicon carbide particles (3-1 and 1-0.088 mm) and fine powder (<0.088 mm),silicon powder (<0.088 mm),industrial carbon black (N990),microsilica,and ρ-Al₂O₃,etc.as raw materials.The new blocks were compared with silicon nitride bonded silicon carbide brick,self-bonded silicon carbide brick and imported self-bonded silicon carbide brick to analyze and evaluate their service performance.The results show that:(1)in the 0-100 mm zone,the new SiC large block manly consists of composites of β-SiC and one or more nitrides such as O’-SiAlON,β-SiAlON,α-Si₃N₄,and Si₂N₂O,the bulk density is 2.68-2.70 g·cm^-3,the apparent porosity is 14%-15%,and the material structure is uniform;(2)in the 0-100 mm zone,β-SiC nano-whiskers intercalate with nitrides;with the depth increasing,the flocculent β-SiC nano-whiskers increase,while the nitrides decrease;when the depth reaches 150 mm or more,the main bonding phases are β-SiC and mullite;(3)compared with the reference products,the new SiC block has a good basic performance,and after alkali corrosion,the mass change rate is -0.1%,which is obviously superior to the imported self-bonded silicon carbide and the homemade silicon nitride bonded silicon carbide materials.

Key words: blast furnace for iron-making, tuyere, silicon carbide, alkali corrosion resistance

摘要： 以碳化硅颗粒(3～1、1~0.088 mm)与细粉(<0.088 mm)、硅粉(<0.088 mm)、工业炭黑(牌号N990)、二氧化硅微粉和ρ-Al₂O₃粉等为原料制备了炼铁高炉用碳化硅风口组合大砖,并与氮化硅结合碳化硅砖、自结合碳化硅砖、国外进口自结合碳化硅砖对比,分析与评估新型碳化硅风口组合大砖的使用性能。结果表明:1)0~100 mm 区域主要由O’-SiAlON、β-SiAlON、α-Si₃N₄、Si₂N₂O等一种或多种氮化物与β-SiC复相结合而成,体积密度2.68~2.70 g·cm^-3,显气孔率14%~15%,组织结构均匀。2)0~100 mm区域β-SiC纳米晶须与氮化物有穿插生长现象;随着深度增加,絮状β-SiC纳米晶须增多,氮化物减少,深度150 mm后结合相主要为β-SiC和莫来石。3)与参比制品比较,新型碳化硅风口组合大砖具有良好的基础性能指标,熔碱侵蚀后质量变化率-0.1%,明显优于进口自结合碳化硅和国产氮化硅结合碳化硅材料。

关键词: 炼铁高炉, 风口, 碳化硅, 抗碱侵蚀性能