高铬型钒钛磁铁矿中铬氧化物还原热力学影响因素分析

Analysis of reduction thermodynamics influencing factors of chromium oxide in high chromium vanadium-titanium magnetite ore

为了研究高铬型钒钛磁铁矿中铬氧化物的还原热力学,通过对铬氧化物间接还原条件下逐级还原规律进行理论计算,得到了在1个标准大气压、不考虑铬的活度情况下的Cr-O-CO系平衡状态图,分析了得到了铬氧化物稳定存在的温度区间。通过对已知成分的含铬铁水进行分析,发现提高C、Si、P、S的质量分数会降低铬的活度,从而改善Cr_2O_3的还原条件,而Mn、V、Ti、Cr质量分数的增加则具有相反的作用;并且铬的活度随着温度的升高而增大,计算得到了在铁水成分不变时Cr_2O_3的开始还原温度为1 134K。通过研究体系压力对Cr_2O_3还原的影响,发现增加反应体系的压力会使Cr_2O_3的开始还原温度升高。

In order to investigate the reduction thermodynamics of chromium oxide in high chromium vanadium-titanium magnetite ore, the equilibrium diagram of Cr-O-CO system under a standard atmospheric pressure without thinking the activity of chromium was obtained by the theoretically calculation of the rule of step-by-step indirect reduction of chromium oxide. Moreover, the tem- perature interval of steady existence of chromium oxide was analyzed. The activity of chromium decreases by increasing the mass fraction of C, Si, P and S, but it can be raised by increasing the mass fraction of Mn, V, Ti and Cr. The activity of chromium in- creases with the increase of temperature when the composition of hot metal is fixed, and the initial reduction temperature of Cr2 Oa decreases to 1 134 K. When considering system pressure, the initial reduction temperature of Cr2O3 goes up with increasing sys- tem pressure.