论文部分内容阅读
采用原位观察和同步热分析的方法,研究了CaO和MgO对氧化铁气基还原过程中金属铁的成核和生长过程的影响。并结合扫描电镜、能谱和红外光谱等分析,从微观角度揭示矿相组成CaO、MgO对气体还原时气固界面上金属铁析出行为的影响机理。实验结果表明,CaO和MgO通过改变FeO→Fe转变速率来影响金属铁析出形态。其中掺入MgO是通过降低还原速率的方式抑制铁晶须生长,掺入质量分数达2%即可完全消除铁晶须;而CaO通过加速还原来抑制铁晶须生长,掺入质量分数达8%时铁晶须消失。
The effects of CaO and MgO on the nucleation and growth of metallic iron during the reduction of iron oxide were studied by in situ observation and simultaneous thermal analysis. Combined with the analysis of SEM, EDS and IR, the influence mechanism of CaO and MgO on the precipitation behavior of metal iron at gas-solid interface during gas reduction was revealed microscopically. The experimental results show that CaO and MgO affect the metal iron precipitation by changing the transformation rate of FeO → Fe. The incorporation of MgO by reducing the rate of reduction of the way to inhibit the growth of iron whiskers, mixed mass fraction of 2% to completely eliminate the iron whiskers; and CaO by accelerating the reduction to inhibit the growth of iron whiskers doped with mass fraction of 8 % When the iron whiskers disappear.