| 摘要 |
<P>PROBLEM TO BE SOLVED: To prepare hard ferrite powder of proper characteristics as permanent magnet in a short time, without using a crusher. <P>SOLUTION: A water solution of metal chloride MCl<SB>2</SB>such as BaCl<SB>2</SB>, SrCl<SB>2</SB>, etc. is mixed with fine powder of Fe<SB>2</SB>O<SB>3,</SB>whose average particle size preferably is 0.1-2.0μm, with 0.5-1.0μm, so that MCl<SB>2</SB>dissolved in the water solution is 1.0 mol with respect to 5.0-6.2 mol of Fe<SB>2</SB>O<SB>3</SB>. The slurry having this ratio is preferably heated at the melting point of the MCl<SB>2</SB>to 1250°C, with 1000-1200°C, for 1-5 hours, with 1-3 hours preferred. The element M is a metal element, constituting a magnet plumbite type hexagonal ferrite, represented by a formula MO-nFe<SB>2</SB>O<SB>3</SB>(n=5.0-6.2). A thick water solution of metal chloride having an amount of dissolved MCl<SB>2</SB>is 90% to saturation amount, is appropriately used. <P>COPYRIGHT: (C)2004,JPO |
