| 摘要 |
PURPOSE:To produce magnetic metallic powder which is free from the deterioration in the magnetic characteristics and dispersibility with high reduction efficiency by coating a needle-like metallic compd. consisting essentially of iron oxyhydroxide or iron oxide with a sintering preventive agent then spray-drying the compd. and reducing the powder by heating. CONSTITUTION:The sintering preventive agent is deposited on the needle-like metallic compd. powder contg. the iron oxyhydroxide or iron oxide as the essential component. The silicate compd. of water soluble silicate such as water glass, sodium orthosilicate or potassium metasilicate is suitable as the above- mentioned sintering preventive agent and such compd. is deposited on the above- mentioned metallic compd. powder dispersed in water. The needle-like metallic compd. coated with the sintering preventive agent is spray-dried to form granules. The resulted granular metallic compd. is reduced by heating in a reducing atmosphere of gaseous hydrogen, etc. kept at about 300-600 deg.C by which the magnetic metallic powder having the excellent dispersibility is efficiently obtd. without the deterioration in the magnetic characteristic owing to the sintering and sticking of the needle-like particles, etc.
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