氧化铁气基还原过程的气体氧化动力学

Oxidizing kinetics of reducing gas during iron oxide reduction process

为了研究氧化铁气基还原过程的气体氧化过程,给出了气基还原单个/单层氧化铁颗粒(球团)的气体利用率计算公式,并建立了氧化铁还原及还原气体氧化的耦合动力学模型。结合氢气还原单颗粒氧化铁以及氧化铁固定床、流化床还原试验得出,在还原分数较低时,气体利用率较高,但是随着还原分数的提高,气体利用率不断下降、还原时间明显延长。缩小颗粒粒度、提高反应速率常数(温度、优质还原剂、催化剂等)等措施有利于提高还原分数和气体利用率;单纯提高气体速度(增加气矿比),有利于提高还原分数,但是使气体利用率降低。

To research the process of reducing gas oxidized by iron ore,gas efficiency of single or monolayer iron oxide particle during gas-based reduction process was calculated through formula and coupled kinetic model of iron oxide reduction and reducing gas oxidation was established by theory and experiment in different reactors.The results show that gas efficiency is relatively high when reduction fraction is low,and drops gradually with the reduction fraction increasing through the reduction experiments of single iron oxide reduction process with hydrogen and iron oxide at fixed and fluidized bed. It is advantageous to increase reduction fraction of iron ore and gas efficiency by pulverizing oreand increasing reaction rate constant（including temperature,high quality reducing gas,catalyst）.Increasing gas flow helps iron ore reduction,but it induces gas efficiency drop.