Kinetics of Fe3O4 formation by air oxidation①
来源期刊：中南大学学报(英文版)2004年第2期
论文作者：杨喜云 龚竹青 刘丰良
文章页码：152 - 155
Key words：Fe3O4; kinetics; air oxidation
Abstract: The kinetics of Fe3O4 formation by air oxidation of slightly acidic suspension of Fe(OH)2 was studied. The effects of initial concentration of Fe(Ⅱ), temperature, partial pressure of oxygen, air flow rate and stirring rate on the oxidation rate were investigated. The results show that Fe3O4formation is composed of two-step reaction, the first step is the formation of Fe(OH)+2 by oxidation of Fe(OH)+ complex ions, the second step is the formation of magnetite by de-hydration and deprotonation of Fe(OH)+ and Fe(OH)+2. The oxidation reaction is zero-order with respect to the concen-tration of Fe(Ⅱ) and around 0.5-order with respect to partial pressure of oxygen, and oxygen transfer process is rate-lim-iting step of oxidation reaction with apparent activation energy of 2.74 kJ·mol-1.
