Li_2CO_3在含碳球团还原中催化机理的研究

STUDY ON THE CATALYSIS MECHANISM OF Li_2CO_3 FOR REDUCTION OF IRON ORE PELLET WITH CARBON

通过在氧化铁中添加碳粉和少量Li2CO3添加剂，考察了碱金属化合物和温度对含碳球团还原过程的影响，探讨了减金属化合物的催化机理，实验结果表明，球团还原车随着碱金属化合物添加量而增大，但增大幅度随添加剂增多、温度升高而减小在球团还原初期，Boudouard反应是还原的限制环节，添加Li2CO3可以降低反应活化能较高温度下球团还原后期，氧化铁的气相还原是反应的限制性环节，添加Li2CO3可以加快Fe／FeO界面上FeO的还原反应,实验条件范围内，温度升高和Li2CO3添加量增加。

Effects of alkadrietal compound and temperature on reduction of carbon containing iron ore penet made by adding the powder of carbon and Li2CO3 into hematite, and the catalysis mechanism of the reduction of iron okides were investigated. The reduction rate of pellet increases with increasing the content of Li2CO3 t but the degree of reduction decreases with increasing the additive and temperature. In the initial stage of pellet reduction, Boudouard reaction is rate-controlling step,and the activation energy of reaction decreases with the increase of Li2CO3 content. In Iater stage under higher temperature, the reduction of iron oxides by carbon monoxide is rate-scontrolling step,tal the reaction between CO and FeO on Fe/FeO interface can be improved by addition of Li2CO3.In the range of experimental condition, the increases of temperature and Li2CO3 can promote thetransform of the rate-controlling step from the Boudouard reaction to the reduction of iron oxides.