| 摘要 |
PURPOSE:To obtain magnetic powder, effectively preventing the collapse and sintering the particles caused by the heat-treatment, by contacting acicular iron oxyhydroxide powder with vapor of a silicon compound prior to the heat-treatment. CONSTITUTION:In the preparation of acicular magnetic powder by the heat- treatment of acicular iron oxyhydroxide, the iron oxyhydroxide powder is brought into contact with the vapor of a silicon compound prior to the heat- treatment. The acicular iron oxyhydroxide is e.g. the powder of alpha-FeOOH, beta- FeOOH, gamma-FeOOH, etc., above all alpha-FeOOH because any kinds of magnetic powder such as magnetite, maghemite, metallic iron, etc. can be produced therefrom. The silicon compound is preferably an easily hydrolyzable compound capable of giving SiO2 easily by the above contacting process. |
