| 摘要 |
PURPOSE:To produce metallic magnetic particle powder having excellent property by passing oxygen-containing gas through a reaction solution of a mixed solution of alkali carbonate with alkali hydroxide with a ferrous salt aq. solution to form a spindle shaped goethite nucleus particle and growing the nucleus particle. CONSTITUTION:A suspension having pH8-10 and containing a FeCO3 precipitate is formed by mixing the aq. solution of ferrous salt such as ferrous sulfate with the mixed aq. solution of alkali carbonate such as Na2CO3 with alkali hydroxide such as NaOH. The fine particle having uniform particle size, absent in dendritic particle, having excellent coercive force and coercive distribution and consisting essentially of Fe is produced by passing the oxidizing gas such as air through the suspension to form the spindle shaped goethite nucleus particle, further adding the mixed solution of the alkali carbonate aq. solution with the alkali hydroxide aq. solution and the ferrous salt aq. solution again to allow it to react with each other, stirring and mixing with the addition of water glass, successively passing the oxidizing gas such as air again to glow the spindle shaped goethite nucleus particle and after that, filtering, separating, drying and pulverizing. |
