| 摘要 |
PURPOSE:To prevent the change of needle type shape occurring by sintering in particles and the roughening of bridges and particles occurring by sintering between particles in a reducing process, by adding boron compound to specified granulation forming and the like, before iron compound whose main component is water-containing iron oxide or iron oxide is subjected to heat treatment and heat-reducing process. CONSTITUTION:Iron compound whose main component is water-containing iron oxide or iron oxide is subjected to granulation forming, heat treatment at 600-900 deg.C in a non-reducing atmosphere, and heat-reducing process. In this manufacturing method of magnetic metal powder for magnetic recording, granulation forming is performed by a rolling system granulation method, boron compound is added at the time of granulation forming, and aluminum compound and/or silicon compound are added. The above iron compound whose main component is water containing iron oxide or iron oxide contains at least one kind of the following metal or its compound; Mg, Mn, Zn, Ni, Si, B, Al, Ag, Cu, P, Sn and W. The specific surface area of water- containing iron oxide is 55m<2>/g or higher, and the specific surface area of iron oxide is 40m<2>/g or higher. |
