# US 4,397,691 A · Method for producing Fe-B molten metal

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- Number: US 4,397,691 A
- Document ID: US4397691A
- Status: Granted
- Kind: A
- Application number: 06/401,001
- Filed: 1982-07-22
- Granted: 1983-08-09
- Earliest claimed: 1981-10-30
- Assignees: Kawasaki Steel Corporation
- Inventors: Takao Hamada; Nobuo Tsuchiya; Toshihiro Inatani; Yoshiyasu Takada; Mitsuo Sumito; Eiji Katayama; Toshimitsu Koitabashi; Kyoji Okabe; Yo Ito
- Web page: https://patentgrep.com/patent/US4397691A

## CPC

- C22C 33/003: {making amorphous alloys}
- C22C: ALLOYS (treatment of alloys C21D, C22F)

## Abstract

Fe-B molten metal for producing amorphous alloys are produced in a low cost by using a vertical furnace wherein beds packed with a carbonaceous solid reducing agent are formed and two or three stages of tuyeres are provided in the lower portion of said furnace, feeding a preliminarily reduced powdery iron ore into the furnace through the upper stage of tuyeres together with hot air and feeding boron oxide or boric acid into the furnace through the lower stage of tuyeres together with hot air and, if necessary blowing hot air into the furnace through the lowest stage of tuyeres. In stead of the above described vertical furnace, a usual blast furnace provided with one or two stages of tuyeres at the lower portion of said furnace is used. In this case, sintered iron ore, pellet-formed iron ore or lump iron ore is fed from the top of the furnace and powdery boron oxide or boric acid is fed through the tuyeres.

## Claims

### Claim 1

A method for producing ferro-boron which comprises introducing a reducing gas into a fluidizing furnace, the reducing gas being exhausted from a vertical furnace which is filled with a carbonaceous solid reducing agent and provided with a plurality of tuyeres at an upper stage and a lower stage, respectively, at the lower portion thereof, preliminarily reducing powdery iron ore in the fluidizing furnace with the exhausted reducing gas feeding the resulting preliminarily reduced iron ore together with hot air through the tuyeres at the upper stage into the vertical furnace, and feeding powdery boron oxide or boric acid in a weight ratio of boron oxide to iron oxide being 0.05-0.8 together with hot air through the tuyeres of the lower stage into the vertical furnace to subject the preliminarily reduced iron oxide ore and boron oxide or boric acid to reduction reaction.

### Claim 2 (depends on 1)

The method as claimd in claim 1, wherein hot air is blown into the furnace through addtional plurality of tuyeres provided at the stage which is lower than the stage of the tuyeres for feeding boron oxide or boric acid in the vertical furnace.

### Claim 3

A method for producing ferro-boron which comprises feeding iron oxide and coke into a blast furnace provided with a plurality of tuyeres at the lower portion thereof, and feeding powdery boron oxide or boric acid in a weight ratio of boric acid to iron oxide being 0.05-0.8 into said furnace through the tuyeres to melt and reduce boron oxide or boric acid.

### Claim 4 (depends on 3)

The method as claimed in claim 3, wherein hot air is blown into the blast furnace through additional plurality of tuyeres provided at the stage which is lower than the stage of the tuyeres for feeding boron oxide or boric acid in the blast furnace.