CO气氛下MgO对Fe_2O_3还原时金属铁析出微观行为的影响

Effect of MgO on Micro-behavior for Precipitation of Metallic Iron in Fe_2O_3 Reduction under CO Atmosphere

利用高温光学体视显微镜和高温热台研究MgO对CO还原Fe2O3中铁晶须成核、生长的影响,并结合SEM、EDS、TG、红外光谱等,从微观角度揭示MgO对还原过程气固界面上金属铁的析出形态的影响机理。结果表明,掺入MgO能有效改变氧化铁还原后析出铁的形态,抑制了铁晶须成核和生长;当掺入质量分数超过2%时,还原后金属铁全部以层状晶析出,无铁晶须形成。

The effects of MgO on the nucleation and growth of iron whiskers and their mechanism in Fe2O3 reduction with CO were study with stereo optical microscope and hot stage.The effecting mechanism of MgO on the precipitation morphology of metallic iron at the gas-solid interfaces during reduction was revealed from micro aspect with SEM,EDS TG and FT-IR.The results indicate that doped MgO can effectively change the precipitation morphology of metallic iron after the reduction of Fe2O3,and inhibit the nucleation and growth of iron whiskers.When the amount of MgO addition is more than 2 %（mass）,all metallic iron forms as laminate crystal,and iron whiskers could not be observed.