高磷鲕状赤铁矿气化脱磷动力学研究

为探索烧结过程中高磷鲕状赤铁矿的脱磷机理, 采用综合热分析仪, 在升温速率分别为10、15、20 ℃/min的条件下, 通过与Fe₂O₃的对比试验, 对高磷铁矿进行了气化脱磷动力学研究。结果表明: 气化脱磷反应在第2失重阶段发生, 且温度为850 ℃时, Ca₅(PO₄)₃F和脱磷剂反应开始, 1 050 ℃左右, 脱磷反应最剧烈。采用Ozawa法计算了高磷铁矿反应的第1、2阶段和Fe₂O₃反应的第2阶段活化能, 分别为104.71, 250.55和168.80 kJ/mol, 脱磷反应过程中克服能垒需要更高能量; 气化脱磷反应机理函数符合二维扩散Valensi方程。

Kinetic Study for Gasification Dephosphorization of High-phosphorus Oolitic Hematite

In order to explore the dephosphorization mechanism in the sintering process of high-phosphorus oolitic hematite, the kinetics of gasification dephosphorization of high-phosphorus iron ore were studied with heating rate at 10, 15 and 20 ℃/min respectively, based on the contrast experiment with Fe₂O₃ by using simultaneous thermal analyzer. The results showed that the gasification dephosphorization occurred at the second stage of weight loss, and Ca₅(PO₄)₃F and dephosphorization agent began to react when the temperature increased to 850 ℃, with the reaction reaching a maximum at 1 050 ℃. The Ozawa method was used to calculate the activation energy at two stages of reaction of high-phosphorus iron ore and the second stage of Fe₂O₃ reaction, leading to the values of 104.71, 250.55 and 168.80 kJ/mol. It is found that more energy will be taken to overcome the energy barrier in the gasification dephosphorization process and the reaction mechanism is in consistent with the two-dimensional diffusion Valensi equation.