镁碳砖在氧化气氛中的脱碳动力学研究

CARBON-OXIDATION KINETICS OFCARBON-BONDED MAGNESIA BRICKIN OXIDIZING ATMOSPHERE

本文作者采用热重分析技术(TGA)研究了STB复吹转炉工艺底枪保护砖——镁碳砖在氧化性气氛中的脱碳动力学,并建立了脱碳动力学模型。实验结果表明,在高温下镁碳砖的脱碳反应控制环节是脱碳层内的气相传质,因而,脱碳速率取决于脱碳层内的透气性。金属添加剂的氧化能降低脱碳层的透气性。在实验温度范围内(1100～1400℃),氧的脱碳速率约为二氧化碳的2.5～3.0倍。

In the paper, carbon-oxidation kinetics of MgO-C bricks used for the tuyeres of STB conv-erter has been investigated by the thermogravimetric analysis (TGA) and the model for car-bon-oxidation kinetics has been established. Experimental results show that the key to con-trol carbon-oxidation of MgO-C brick is mass transfer of gas in the decarbonized layer andthe rate of carbon oxidation is dependent on permeability of that layer. The oxidation ofmetal additives can reduce permeability in the decarbonized layer. In the range of experimen-tal temperature (1100--1400℃), the carbon-oxidation rate in oxygen is about 2.5--3.0 timesas larse as that in CO_2.