Mannesmann Aktiengesellschaft

Klaus Grebe

Norbert Dautzenberg

Josef Hewing

Hans De Haas

Iron oxide powder, e.g., ore, is reduced in a CO/N.sub.2 atmosphere at a temperature between 750.degree. to 1200.degree. C., whereby prior to the onset of precipitation of metallic iron the content of H.sub.2 is limited to 15% (vol) of the CO content, and SO.sub.2, H.sub.2 S, COS or another suitable gaseous sulphur compound is developed or maintained in the reducing atmosphere at a range from 0.0005 to 0.1% (vol), preferably 0.001 to 0.01% (vol) in relation to the CO content.

Making iron powder having fiber-like particles

Iron oxide particles are made by spray calcination and the oxide is reduced at least substantially in CO at temperatures between 800.degree. and 1000.degree. C. The oxide is heat-treated prior to calcination or CaO is added to enhance formation of iron fibers. The reducing atmosphere may in parts include hydrogen or the last phase of reduction is carried out in hydrogen. The iron cake is cooled and broken up in a grinder. The resulting powder has low bulk density due to a fiber-like, non-porous consistency of its particles. Grinding may continue to increase bulk density.

Growing community of inventors

Kettwig, Germany

Klaus Grebe