| 摘要 |
PURPOSE:To prevent the sudden oxidation and ignition of metal magnetic pow der and improve magnetic characteristics by adding a cooling medium directly to a reaction system. CONSTITUTION:Toluene and metal magnetic powder are left in a dry air at room temperature. A cooling medium supply apparatus for pouring liquid nitro gen automatically when they reach a set temperature is provided. When they reach a set temperature, the apparatus supplies a suitable amount of liquid nitrogen automatically to the liquid toluene, its temperature is lowered, and it is left continuously. If toluene is evaporated and removed, a rise in the temper ature of the metal powder is not recognized even if it is left for one hour as it is. The metal magnetic powder in which initial oxide film formation processing has been performed are subjected to heat treatment continuously, and then they are cooled naturally. As a result, the temperature of an organic solvent can be controlled below a certain temperature. The oxidation reaction of metal non-oxide magnetic powder can be controlled, and a fine oxide film can be formed efficiently. |
