| 摘要 |
PURPOSE:To manufacture metallic magnetic powder suitable for a magnetic recording material by a method wherein a silicon compound is applied and treated on the surfaces of the particles of an iron oxide hydrate, and changed into hematite through heat treatment, and an aluminum compound is applied and treated on the surfaces of the particles of obtained hematite and reduced and treated by heating. CONSTITUTION:Needle geothite is suspended in water, a nickel chloride aqueous solution is added, and pH is adjusted to 8 by using ammonia water. A sodium orthosilicate aqueous solution is added, pH is adjusted % 8 by adding ammonia water, and a silicon compound is applied and treated. The whole is dehydrated through heat treatment in atmospheric air, changed into hematite, and dispersed in water. A sodium aluminate aqueous solution is added, pH is adjusted to 8 by employing hydrochloric acid, and an aluminum compound is applied and treated. Metallic magnetic powder is acquired through reduction by heating in a steam flow. |
