摘要
借助于热分析仪,通过热重分析研究了(Al_2O_3–C)/Fe体系中的反应动力学特征。在氩气气氛和不同升温速率下,对(Al_2O_3–C)/Fe试样进行了热重实验。计算出不同阶段反应的活化能Ea、指前因子A和反应速率常数k,同时,提出了(Al_2O_3–C)/Fe体系反应的2个阶段,铁熔化前为第1阶段,主要是氧化铝和碳之间的固–固反应,铁熔化后为反应的第2阶段,主要为固–液反应阶段。在高温条件下,铁液的参与使得反应速率加快,促进了氧化铝碳热还原反应的进行。
The kinetic characteristics of reaction in(Al_2O_3–C)/Fe system was investigated by thermogravimetric analysis.(Al_2O_3–C)/Fe powders were heated under argon atmosphere at different heating rates in the thermal analyzer. The activation energies, Ea, the pre–exponential factor, A, and the reaction rate constants, k, were calculated. The reaction stages of(Al_2O_3–C)/Fe were also analyzed. The reaction are mainly solid–solid reaction between corundum and graphite at the first stage before iron melts. The reaction occurs in the solid–liquid reaction stage in the presence of iron liquid when iron powder completely melts. The result by thermogravimetric analysis indicates that the participation of iron liquid can accelerate the carbothermic reduction of alumina at a high temperature.
引文
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