| 摘要 |
PURPOSE:Fine needles of iron oxyhydroxide containing specific amounts of aluminum and phosphorus as trace minor components is oxidized or reduced under heating to produce the titled fine particles almost free of damage, destruction in shapes and sintering of particles. CONSTITUTION:Fine needles of iron oxyhydroxide containing aluminum and phosphorus by 0.05-5pts.wt. per 100pts.wt. of iron are prepared. The fine particles are dried, when necessary, tentatively roasted and heated in a steel reactor whose temperature can be controlled under introducing an oxidizing gas or reducing gas at a prescribed temperature to produce particles of ferromagnetic iron oxide (Fe3O4, gamma-Fe2O3) or ferromagnetic metallic iron (alpha-Fe). |
