| 摘要 |
This invention relates to magnetite particles with a mean particle size of 0.1 to 0.3 mum, a specific surface area of 6 to 9 m2/g, a coercive force of 80 to 110 Oe, a residual magnetization of 13 to 20 nTm3/g, a pH of 7 to 10 and a bulk density of 0.6 to 0.9 g/cm3, by heating an aqueous solution of an alkaline component under inert gas, to a precipitation temperature of 65-85° C., adding iron (II) and iron (III) components and oxidizing the suspension with an oxidizing agent at a speed of 7-25 mol % Fe (II)/h. |
