| 摘要 |
PURPOSE:To provide a method for production in which granular magnetite grain powder having a uniform gain size is industrially obtained. CONSTITUTION:Granular magnetite grain powder is produced by a method for heating a suspension at pH >=6 containing hydrous ferric oxide grain powder and ferrous hydroxide at >=40 deg.C temperature. In the process, mixed powder of goethite grain powder and lepidocrosite grain powder is used as the aforementioned hydrous ferric oxide grain powder and the abovementioned lepidocrosite grain powder is present in an amount of 5-95wt.% based on the aforementioned mixed powder. Thereby, the objective granular magnetite drain powder having a uniform grain size is obtained. |
