低品位赤铁矿球团成核剂强化还原机理研究

Mechanism of action of improving reduction on low grade hematite pellets by adding nucleating agent

摘要: 对某低品位赤铁矿球团直接还原过程中成核剂作用机理进行了研究.结果表明:在直接还原过程中,成核剂能够使金属铁晶粒形核位垒降低50%以上,有效促进了金属铁晶粒快速形核.同时,添加成核剂后,球团的还原表观活化能由18.10kJ·mol^-1降低到10.15 kJ·mol^-1,降低了43.92%.表观活化能越低,还原反应越容易进行,即成核剂能够有效促进铁矿物还原,从而提高还原球团的金属化率.

Abstract: The mechanism of action of nucleating agent was studied during the direct reduction of low grade hematite pellets in Central South China.The results show that the nucleating barrier is reduced by over 50% by adding a nucleating agent in the hematite pellets,which can effectively improve the nucleating of metal iron grains during the direct reduction.Because of the nucleating agent,the apparent activation energy of the hematite pellets decreases from 18.10 kJ·mol^-1 to 10.15 kJ·mol^-1,dropping by 43.92%.The lower the apparent activation energy,the easier the reduction reaction takes place.It is concluded that the nucleating agent can efficiently improve the direct reduction and upgrade the metallization degree of the reduced pellets.