Research on Kinetics of Rich Hydrogen Reduction of Baiyunobo Iron Concentrate Pellets
-
摘要: 针对气固直接还原工艺中存在着气体利用率低和还原供热不足等问题,利用恒温热重分析(TG)法,研究了氢/碳比率对白云鄂博铁精矿还原速度的影响。结果表明,在还原试验开始后40 min内,还原速率随wH2/wCO比增加而增大,使得Fe2O3→Fe3O4反应时间缩短。基于气相内扩散和界面反应的球团还原速度方程均能较好地处理本研究的数据,得到了反应速度常数与wH2/wCO的关系为:k界面=-0.1975+0.3 575wH2/wCO,k扩散=0.171 01+0.269 7wH2/wCO。根据Arrhenius方程计算出界面反应和气相内扩散活化能分别为26 kJ/mol和44 kJ/mol,因此本研究条件下限制性环节为气体内扩散控制。Abstract: The wH2/wCO ratio on the influence of reduction rate of Baiyun obo iron concentrate pellets was studied by homoiothermy thermogravimetric analysis （TG） method in order to solve the low utilization rate of gas and insufficient supply of heat problems in gas- solid direct reduction process.. The results showed that the reduction rate increases with increasing wH2/wCO ratio in 40 minutes after reduction test,and then reduce Fe2O3→Fe3O4 reaction time. Based on the gas phase diffusion and interface reaction of pellets reduction rate equations the calculated relationship of reaction rate constant and wH2/wCO are: kinterface=- 0.197 5 + 0.357 5wH2/wCO,kspread= 0.171 01 + 0.269 7 wH2/wCO respectively. The activation energy of the interface reaction and the gas phase diffusion calculated by Arrhenius equation are respectively 26 kJ /mol and 44 kJ /mol,and this indicates that gas diffusion control is a restrictive link under this study condition.
-
点击查看大图
计量
- 文章访问数: 100
- HTML全文浏览量: 17
- PDF下载量: 2
- 被引次数: 0
下载:
