摘要
系统分析了铁矿石还原性的影响因素以及铁矿石的气固还原动力学特征,铁矿石的化学成分、孔隙率和矿物组成对其还原性都有影响,总体来看,铁矿石中的碱性氧化物对铁矿石的还原有促进作用,而酸性氧化物对其还原有阻碍作用。提高铁矿石中微气孔的比例以及提高还原性好的矿物,如铁酸钙的含量可改善铁矿石的还原性;对于铁氧化物气固还原动力学的研究大多采用未反应核模型,在还原的不同阶段具有不同的限制性环节,比如在浮士体还原到金属铁阶段,前期还原反应由气体内扩散与界面化学反应混合控制,后期界面化学反应为还原反应的控制环节。总结前期的研究结果,结合当前资源现状提出了今后铁矿石还原行为的2个研究方向:①加强Al2O3、K2O、Na2O、ZnO等杂质元素和有害元素对铁矿石还原性影响研究;②加强高炉实际含铁原料,如烧结矿、球团矿和块矿的气固还原动力学研究。
The various factors that influence the reducibility was systematically studied in this paper. The reducibility of of iron ore and the characteristic of reduction kinetics iron ore was affected by the chemical composition, porosity and mineral composition. Overall, the basic oxide will promote the reduction of iron ore, while the acid oxide will retard the reduction. The reducibility of iron ore can be improved by increasing the content of micro pore and easily reduced mineral phase, such as calcium ferrite. Generally, unreacted core model was applied to study the gassolid reduction kinetics of iron ore. The controlling steps were different in different stages of the reduction. In the case of reduction from wustite to metal iron, the reduction was controlled by gas diffusion and interface chemical reaction at the early stage of reduction. At the final stage, it was controlled by interface chemical reaction. According to the current study and resources status, two aspects on the study of iron ore reduction were proposed： ① the influence of Al2O3, K2O, Na2O, ZnO on the reduction behavior of iron ore②the study of gas-solid reduction kinetics of actual BF ferrous burden, such as sinter, pellet and lump.
出处
《中国冶金》
CAS
2013年第4期1-6,共6页
China Metallurgy
基金
国家自然科学基金资助项目(51274026)
钢铁联合研究基金资助项目(50874129)
国家高技术研究发展计划(863)资助项目(2009AA06Z105)
关键词
气固还原
铁矿石
还原性
还原动力学
gas-solid reduction
iron ore
reducibility
reduction kinetics
