CONTINUOUS PRODUCTION OF BA-FERRITE FINE POWDER

摘要

PURPOSE:To produce the Ba-ferrite fine powder having a small particle diameter stably and continuously by introducing an alkaline suspension containing Fe or magnetite and Ba ion forcibly into a tubular reaction tube and by allowing to react them. CONSTITUTION:As required, an M(II) or M(IV)-M(II) system compound (example: sodium stannate) and a surfactant (example: sodium oleate) are added into an alkaline suspension containing Fe(III) or magnetite and Ba ion to prepare a reaction slurry 1. Said slurry 1 is introduced forcibly into one end of a tubular reactor 3 kept at 250-400 deg.C by being dipped in a heating medium 5, it is allowed to react so as to complete the reaction at the outlet of the reactor 3 by controlling the retention time and is then recovered in a reservoir 8. By doing this, Ba-ferrite particulates whose usable particle diameter as a coating- type vertical magnetic recording medium is small and whose shape is of a hexagonal plate is obtained.