| 摘要 |
PROBLEM TO BE SOLVED: To easily obtain ferrite carrier cores having fine surface raggedness while keeping almost uniform apparent density and having a specific surface area which does not adversely affect coatability by mixing powders obtd. by firing starting materials for ferrite at two kinds of different temporary firing temps. and then carrying out concluding firing. SOLUTION: Starting materials for ferrite such as Fe2 O3 , MgO, ZnO, CuO and MnO2 are mixed, granulated and fired S4, S14 at two kinds of different temporary firing temps. The resultant powders are mixed and successively subjected to wet pulverization S6, granulation S7, concluding firing S8, crushing S9, size conditioning S10, classification S11, sieving S12 and magnetic separation S13 to obtain the objective ferrite carrier cores S14. The temporary firing temps. are within the range of 800-1,400 deg.C and are different from each other by >=100 deg.C. The desired apparent density and coatability are ensured by regulating the temps., e.g. to 800 deg.C for S4 and 1,400 deg.C for S14. The amt. of the powder fired at the higher temporary firing temp. is preferably 5-30mol% of the total amt. of the powders. |
