PRODUCTION OF MAGNETIC METAL POWDER CONSISTING OF IRON OR ESSENTIALLY OF IRON

申请公布号：JPS58126905(A)

申请号：JP19820007565

申请日期：1982.01.22

申请公布日期：1983.07.28

申请人：

TOYO SODA KOGYO KK

发明人：FUJII OSAMU;HIRAGA YOUICHI;INOUE TAKAHIKO

分类号：B22F9/22;H01F1/06

主分类号：B22F9/22

摘要：PURPOSE:To produce powder of magnetic iron having excellent magnetic characteristics by subjecting iron or alpha-oxyhydroxide consisting essentially of iron of suitable particle consitution to hydrothermal treatments in an aq. alkali soln. and coating the same with compds. of Si, etc. then subjecting the same to hydrogen reduction. CONSTITUTION:Fine powder in the acicular form having <=0.4mum long diameter and <=0.04mum which (short diameter) as iron or alpha-oxyhydroxide consisting essentially of iron is subjected to hydrothermal treatments for 2-10min at 150- 180 deg.C in an aq. alkali soln. of 0.1-2N to improve acicular crystals; thereafter, at least 1 kind among oxides of Si, Al or Bi, salts of oxides or hydroxides are added thereto and again the powder is subjected to hydrothermal treatments for 2-10min at 100-180 deg.C to form coatings of said additives; thereafter, the powder is subjected to filtering, drying and further to hydrogen reduction at 300-600 deg.C. The amt. of the additives to be added for the purpose of forming said coatings is preferably in a 0.001<=(Si+Al+Bi)/Fe<=0.02 by atomic weight.