共沉法制备锰锌软磁铁氧体前躯体的热力学分析

Thermodynamic Analysis on the Preparation of Mn-Zn Soft Magnetic Ferrite Precursor by Coprecipitation Method

通过对Fe(Ⅱ)-Mn(Ⅱ)-Zn(Ⅱ)-CO32--NH3-H2O系的热力学分析,得到各金属离子浓度与pH值的关系,从而确定共沉法制备锰锌软磁铁氧体微粉的共淀区域。热力学分析表明,三者的共沉区域包含在Zn2+沉淀完全的区域内,而Zn2+沉淀完全的区域由[C]T和[N]T的相对关系所决定。此外,Fe2+沉淀完全的区域只与[C]T有关。确定Fe2+、Mn2+、Zn2+三者的共沉区域,对于锰锌软磁铁氧体微粉的生产具有重要的指导意义。

The thermodynamic analysis on the system of Fe(Ⅱ)-Mn(Ⅱ)-Zn(Ⅱ)-CO32--NH3-H2O is carried out. The relationship between pH value and the total concentrations of Fe(Ⅱ), Mn(Ⅱ) and Zn(Ⅱ) is obtained, and the field of coprecipitation of Fe(Ⅱ), Mn(Ⅱ) and Zn(Ⅱ) is obtained at a suitable pH value. The results show that the field of coprecipitation is included in the field of precipitation of Zn(Ⅱ), while the field of precipitation of Zn(Ⅱ) is determined by the reciprocal ship of [N]T and [C]T. Furthermore the field of precipitation of Fe(Ⅱ) is related with [C]T only. Confirming the coprecipitation of Fe(Ⅱ), Mn(Ⅱ) and Zn(Ⅱ) it has important significance to prepare Mn-Zn soft magnetic ferrite ultrafine.