Patent Number: 6,296,479

Title: Direct reduction method and rotary hearth furnace

Abstract: Raw materials, including a metal oxide and a carbonaceous material, are supplied into a rotary hearth furnace. Then, the raw materials are heated and reduced by burners, which are arranged to cause a strong stirring action for an atmosphere around the raw materials, in an early reducing period that is defined as a period during which 70-80% of a total amount of a flammable gas generated from the raw materials is generated. In a latter period subsequent to the early reducing period, the raw materials are heated and reduced by burners arranged to cause a weak stirring action for an atmosphere around the raw materials, whereby a metal is manufactured. With the present invention, productivity can be improved and the fuel consumption per unit product can be reduced.

Inventors: Nishimura; Makoto (Kobe, JP), Tanaka; Hidetoshi (Kakogawa, JP)

Assignee: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)

International Classification: C22B 5/00 (20060101); C22B 5/10 (20060101); C21B 13/00 (20060101); C21B 13/10 (20060101); C22B 1/16 (20060101); C22B 1/216 (20060101); F27B 9/16 (20060101); F27B 9/30 (20060101); F27B 9/00 (20060101); F27D 23/00 (20060101); F27B 9/36 (20060101); F27B 009/16 (); F23B 007/00 ()

Expiration Date: 10/02/2018