锌对球团矿还原反应的影响  

Effect of Zn on reduction reaction of pellets

作　　者：胡闯开 周进东[1,2] 朱斌 熊玮[1,2] 毕学工[1,2] Hu Chuangkai;Zhou Jindong;Zhu Bin;Xiong Wei;Bi Xuegong(State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,China;Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education,Wuhan University of Science and Technology,Wuhan 430081,China)

机构地区：[1]武汉科技大学省部共建耐火材料与冶金国家重点实验室,湖北武汉430081 [2]武汉科技大学钢铁冶金及资源利用省部共建教育部重点实验室,湖北武汉430081

出　　处：《武汉科技大学学报》2023年第2期87-94,共8页Journal of Wuhan University of Science and Technology

基　　金：国家自然科学基金资助项目(51604199);武汉科技大学青年科技骨干培育计划(2016xz003).

摘　　要：利用浸泡法制得富锌球团矿,测定不同温度下球团矿和富锌球团矿还原失重量随时间变化,建立了球团矿气-固反应的未反应核模型,研究了锌对球团矿还原动力学的影响。结果表明,本实验中,球团矿还原反应控速环节为界面化学反应;球团矿和富锌球团矿的化学反应活化能分别为54.34、54.38 kJ/mol,表明富锌对球团矿还原的阻碍作用十分有限;锌对球团矿还原的影响主要表现在:①表面形成的ZnO壳阻碍球团矿还原,②内部锌蒸气发生循环反应起到催化作用。当温度较低(900℃)时,表面富集的ZnO壳影响大,阻碍球团矿的还原;温度在950~1000℃,锌蒸气催化作用显著,削弱或抵消了ZnO壳的阻碍作用;随着温度继续升高,由于锌蒸气还原FeO反应是放热反应,锌蒸气催化作用降低甚至可忽略不计。Zn-rich pellets were prepared by immersion method.The reduction weight loss values over time of pellets and Zn-rich pellets at various temperatures were measured,and an unreacted nuclear model of pellet gas-solid reaction was established to investigate the effect of Zn on the reduction kinetics of pellets.The results show that under the experimental conditions,the rate-controlling link of pellet reduction is interfacial chemical reaction.The activation energy of chemical reaction of pellets and Zn-rich pellets is 54.34 kJ/mol and 54.38 kJ/mol,respectively,indicating that the hindering effect of Zn-rich on the reduction of pellet is very limited.The impact of Zn on the reduction of pellets is mainly twofold:firstly,the as-formed ZnO shell on the surface hinders the reduction of pellets;secondly,the circulating reaction of internal Zn vapor plays a catalytic role.When the temperature is relatively low(900℃),the surface-enriched ZnO shell dominates,which hinders the reduction of pellets;within the temperature range of 950~1000℃,due to the significant catalytic effect of Zn vapor,the hindering effect of ZnO shell is weakened or even offset;as the temperature continues to rise,since the reaction of Zn vapor to reduce FeO is an exothermic reaction,the catalytic effect of Zn vapor is diminished or even negligible.

关 键 词：球团矿 锌 还原反应 未反应核模型 还原动力学 催化还原 界面化学反应 

分 类 号：TF801[冶金工程—有色金属冶金]