US 5,205,950 A · Process for preparing iron carbide fine particles

Abstract

The present invention provides a process for preparing iron carbide fine particles having an average particle size (long axis) of 0.1 to 2 .mu.m and an average axial ratio of 3 to 20, which comprises, (a) optionally contacting an iron compound selected from the group consisting of iron oxyhydroxide fine particles and iron oxide fine particles with a reducing agent which does not contain carbon atom, the iron compound being, prior to the above contact, coated with iron compound or iron compound and cobalt compound, and with aluminum compound or silicon compound, and (b) contacting the iron compound of the above (a) with a reducing-and-carburizing agent containing carbon atom or a mixture thereof with a reducing agent which does not contain carbon atom.

Claims14

Dependent claims

A process of preparing iron carbide fine particles having an average particle size (long axis) of 0.1 to 2 .mu.m, and an average axial ratio of 3 to 20, comprising:

(a) coating a first iron compound selected from at least one of iron oxide particles and iron oxyhydroxide particles with a first coating composition comprising a second iron compound, which is different from said iron oxide or iron oxyhydroxide, and further with a second coating composition selected from at least one of an aluminum compound or silicon compound to form a coated iron containing composition;
(b) reducing said coated iron containing composition with at least one reducing agent which does not contain carbon atoms;
and
(c) contacting the product of said reducing step (b) with a reducing and carburizing agent comprising at least one compound which contains at least one carbon atom.

1 more element

Dependencies are inferred from the claim text.

Process for preparing iron carbide fine particles

Life of this patent

Process for preparing iron carbide fine particles

Life of this patent

Abstract

Claims14