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利用热重分析的方法研究了Fe2O3在竖式电阻炉内被CO/CO2混合气体还原,Na2O对其还原行为的影响,共设计了4个成分,分别为纯Fe2O3、Fe2O3-1%Na2O、Fe2O3-3%Na2O和Fe2O3-5%Na2O。在还原过程中由于还原失氧引起的试验小饼失重量被实时记录下来,根据这些数据可以计算出还原反应速率以及化学反应的速率常数,以此来判断Na2O对Fe2O3还原性的影响。同时利用扫描电镜观察了还原后试样的微观形貌变化。研究发现:Na2O的存在将阻碍Fe2O3的还原。通过对还原后小饼的显微形貌观察,结合FeO-Na2O二元相图,发现这种负面影响主要是由于在还原过程中产生液相引起的。另外,还检测了还原前后试验小饼的孔隙率和体积变化。检测结果确认:还原后含Na2O的试验小饼的孔隙率和体积都有所下降。分析认为这种现象同样归因于还原过程中液相的产生。
The effect of Na 2 O on the reduction behavior of Fe 2 O 3 in a vertical resistance furnace was studied by thermogravimetric analysis (TGA). Four components were designed, which were pure Fe 2 O 3, Fe 2 O 3 -1% Na 2 O, Fe 2 O 3 -3% Na2O and Fe2O3-5% Na2O. The weight loss of the test cake caused by the reduction of oxygen during the reduction process is recorded in real time. Based on these data, the reduction reaction rate and the rate constant of the chemical reaction can be calculated to determine the effect of Na2O on the reduction of Fe2O3. Scanning electron microscopy was also used to observe the microstructure changes of the samples after reduction. The study found that: the presence of Na2O will hinder the reduction of Fe2O3. By observing the micro-morphology of the reduced cake and combining with the binary phase diagram of FeO-Na2O, it was found that this negative effect was mainly due to the liquid phase generated during the reduction. In addition, the porosity and volume change of the test cake before and after reduction were also examined. The test results confirm that the porosity and volume of the reduced-Na 3 O-containing test cake have decreased. Analysis that this phenomenon is also due to the liquid phase during the reduction process.