MnO2碳热还原动力学及添加剂的影响
来源期刊:中国有色金属学报2000年第5期
论文作者:唐惠庆 郭兴敏 张圣弼 郭占成
文章页码:710 - 714
关键词:MnO2碳热还原;稀土氧化物; 催化作用
Key words:MnO2 carbothermic reduction; rare earth oxide; catalysis
摘 要:在测定MnO2碳热还原表观活化能的基础上, 确认MnO2碳热还原可以分为三个阶段: 1) 在 f <0.3时, 其控制环节为气相扩散, 2) 当0.3< f <0.6时, 其控制环节为碳气化反应, 3) 当 f >0.6时, 其控制环节为固相扩散。 稀土氧化物(La2O3, CeO2和Ce2O3)对MnO2碳热还原有催化作用,并以La2O3效果最佳。 催化的机理在于对碳气化反应的催化。
Abstract: Based on reduction experiment, it is concluded that the carbonthemic reduction of MnO2 is distinctly divided into three stages: gas diffusion controlling stage, carbon gasification controlling stage and solid diffusion controlling stage. The effect of rare earth oxide (La2O3, CeO2 and Ce2O3) on carbothermic reduction of MnO2 was then investigated and it was found that the rare earth oxides have catalytic effect on reduction and La2O3 is the most affective.SEM analysis discloses that the catalytic mechanism is that rare earth oxide catalyzes the carbongasification reaction.