FERRITE MAGNETIC POWDER, OXIDE RAW MATERIAL FOR FERRITE MAGNETIC POWDER AND ITS PRODUCTION

摘要

PURPOSE: To produce Ni-Zn ferrite magnetic powder (or oxide raw material) having fine particle size, uniform composition, form and size and high crystallinity by a coprecipitation process by oxidizing in the presence of a water-soluble compound of Fe, Ni and Zn together with a Cu compound. ;CONSTITUTION: An acidic aqueous solution containing Fe²⁺, Ni²⁺, Cu²⁺ and Zn²⁺ is neutralized by mixing with an alkaline aqueous solution and an oxidizing gas is blown into the obtained mixed solution at a neutralization ratio of 0.7-3.0 and 50-100°C. After completing the oxidization, the slurry mixed solution is filtered, washed with water and dried to obtain crystalline Ni-Zn ferrite magnetic powder or oxide raw material of Ni-Zn ferrite magnetic powder containing 1-30mol% of copper oxide in terms of single oxide and having a particle diameter of ≥0.2μm and a narrow particle size distribution. The product is baked at ≤800°C as necessary. A minor component such as Si, Ca, Sn, Ti, Cr, Co, Al, Mg or Bi is optionally added in the neutralization process in the form of a water-soluble compound.;COPYRIGHT: (C)1996,JPO