PRODUCTION OF FERRITE POWDER

摘要

Fine ferrite powder is produced by adding an ammonium oxalate solution to a solution containing ferrous ions and divalent metal ions to co-precipitate oxalates. After separating, washing and drying the co-precipitated particles, they are calcined for several hours at a relatively low temperature (eg 200 DEG C) before completing the calcination at a higher temperature (eg 800 DEG C). The particles are then vibro-energy or ball milled and dried. …Dense ferrite blocks can be made from the ferrite powder, by pressing the powder into a mold, sintering the molded ferrite and then isostatically at a pressure compacting it at a temperature of 1200 DEG C and at a pressure of 2.00 x 10<8> Pascals. Dense nickel-zinc ferrite blocks produced in this manner are particularly suitable for the manufacture of magnetic transducer heads.