Title:
IRON OXIDE PARTICLE AND ITS PRODUCTION
Document Type and Number:
Japanese Patent JP3499150
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To obtain iron oxide particles with high fluidity as magnetic powder, slight in moisture absorption variance under various circumstances, therefore stable in electrical resistance by coating the surface of iron oxide particles with each specified amount of a molybdenum compound and/or tungsten compound.
SOLUTION: This iron oxide particles are obtained by the following steps: a ferrous hydroxide slurry prepared by neutralization mixing of an aqueous solution of a ferrous salt with an alkali solution is oxidized to form a slurry containing iron oxide core particles; the slurry is then admixed with an alkali and an aqueous solution of a ferrous salt containing molybdenum and/or tungsten, and the resultant slurry is oxidized while keeping the slurry at pH 6-10 and 60-98°C to prepare the objective iron oxide particles coated with a multiple compound of molybdenum and/or tungsten and iron; wherein it is designed that the coating level of the molybdenum compound and/or tungsten compound is 0.01-5 wt.%, calculated as element, based on the iron oxide particles, the specific surface area of the iron oxide particles is 5-25 m2/g, and the FeO content of the iron oxide particles is ≥18 wt.%.
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Inventors:
Hiroyuki Watanabe
Youji Hagino
Youji Hagino
Application Number:
JP10724299A
Publication Date:
February 23, 2004
Filing Date:
April 14, 1999
Export Citation:
Assignee:
Mitsui Mining & Smelting Co., Ltd.
International Classes:
C01G49/08; C01G49/00; G03G9/083; G03G9/10; G03G9/107; (IPC1-7): C01G49/00; C01G49/08; G03G9/083; G03G9/107
Domestic Patent References:
| JP785457A | ||||
| JP2138708A | ||||
| JP8203063A |
Attorney, Agent or Firm:
Osamu Hatori