| 摘要 |
PURPOSE:To obtain fine powder of the titled compound, in high efficiency, by mixing the sulfate of Ba, Sr or Pb with iron oxide, etc., adding the mixture to an aqueous solution of alkali metal hydroxide containing an alkali metal carbonate, heat-treating the mixture, and separating and calcining the produced precipitate. CONSTITUTION:One or more compounds selected from the sulfates of barium, strontium and lead are mixed with one or more compounds selected from hydrated iron oxide, iron oxide, and a travalent iron salt at a Fe/M molar ratio of 10-13 (M is metal of the sulfate). The mixture is added to an aqueous solution of an alkali metal hydroxide having a concentration of >=5N and containing more than equivalent of an alkali metal carbonate based on M. The obtained dispersion is treated at 130-360 deg.C in a closed vessel, and the produced precipitate is separated. The objective fine powder of magnet plumbite ferrite can be produced by calcining the precipitate at 800-1,100 deg.C. The obtained ferrite powder is suitable as the magnetic material for magnetic recording tape, etc. |
