US 6,152,983 AGranted

Method of producing reduced iron pellets

AssigneeKabushiki Kaisha Kobe Seiko Sho

InventorsTsunao Kamijo, Kazuya Miyagawa, Yoshimichi Takenaka, Masakata Shimizu, Shoji Shirouchi, Haruhisa Iwakiri

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Abstract

A carbonaceous material is controlled such that the amount of carbon is from 7 to 60 mass % based on the total amount of iron and Zn in a starting mixture comprising one or more of ducts containing iron oxide and Zn oxide and a binder in an amount to bond the dusts, and water is added to prepare green pellets incorporated with the carbonaceous material. Then, dry pellets prepared by drying the thus prepared green pellets into a reduction furnace, the dry pellets are heated by heat transfer, mainly, radiation such that a temperature elevation rate is from 3 to 13.degree. C./sec within a temperature range from 150 to 900.degree. C. of the pellets, thereby reducing Zn oxide and evaporating Zn, as well as reducing iron oxide to produce reduced iron pellets.

Claims10

Dependent claims

A method of producing reduced iron pellets, comprising the following steps:

1) preparing green pellets from a feed material mixture comprising one or more dusts containing iron oxide and zinc oxide, a binder in an amount sufficient to bond the dusts, and water, wherein said green pellets incorporate carbonaceous material from said one or more dusts and/or added separately, and wherein said green pellets contain an amount of carbon in a concentration of from 7 to 60 mass% based on the total amount of iron and zinc;
2) drying the thus prepared green pellets to prepare dry pellets;
3) feeding the dry pellets to a furnace;
4) heating the dry pellets at a temperature elevation rate of from 3 to 13.degree. C./sec within a temperature range from 150 to 900.degree. C. of the pellets;
and
5) further heating said pellets to temperatures sufficient to reduce said zinc oxide to zinc and evaporate said zinc, and to reduce said iron oxide.

3 more elements

Dependencies are inferred from the claim text.