| 摘要 |
PURPOSE:To manufacture the title magnetism recording magnetic iron oxide powder capable of exhibiting extensive high performance as a magnetism record ing medium as well as lifting the restrictions of Fe<2+>Fe<3+> mole ratio to magnetic iron oxide powder for acquiring the high coersive force by a method wherein calcium, magnesium and silicon compound are made to coexist together on the surface of the cobalt transformed magnetic iron oxide powder. CONSTITUTION:Calcium, magnesium and silicon compound are made to coexist together on the surface of cobalt transformed magnetic iron oxide power. At this time, the cobalt transformed magnetic iron oxide powder is brought into contact with the solution wherein calcium, magnesium and silicon compound are made to coexist together so that the calcium, magnesium and silicon compound may be made coexist together on the surface of the cobalt transformed magnetic iron oxide powder later to be dried up. For example, calcium chloride, magnesium chloride and methasoda silicate respectively as the calcium, magnesium and silicon compound are to be added to an alkaline slurry. |
