| 摘要 |
PURPOSE:To attempt the stabilization of the ferromagnetic metal powder without deterioration of magnetic characteristics by a method wherein after the ferromagnetic metal powder is obtained by a prescribed dry process, slow oxidation treatment is performed as occasion demands and is treated with a peroxide. CONSTITUTION:Needlelike alpha-FeOOH containing a prescribed quantity of cobalt is heated in air at a prescribed temperature to obtain alpha-Fe2O3 having not high crystallization. The mixed powder is put on a board and is treated with reduction treatment in hydrogen atmosphere to convert into a black powder. The temperature of a furnace is made to be about 80 deg.C, the powder is made to dry in the furnace keeping the rising speed of partial pressure of oxygen not to exceed a prescribed value, and is made to absorb a mixed gas of air and N2. The slow oxidation treatment is performed, and the ferromagnetic metal powder obtained by this treatment is dipped in a prescribed quantity of hydrogen peroxide. The ferromagnetic metal powder obtained by this way is separated by suction filtering process and is made to dry at a prescribed temperature to remove water completely to attempt the stabilization of the metal powder without the deterioration of magnetic characteristic. |
