# US 4,397,684 A · Process for pneumatic stirring of a bath of molten metal

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 4,397,684 A
- Document ID: US4397684A
- Status: Granted
- Kind: A
- Application number: 06/354,912
- Filed: 1982-03-04
- Granted: 1983-08-09
- Earliest claimed: 1981-03-11
- Assignees: Institut de Recherches de la Siderurgie Francaise (IRSID)
- Inventors: Jean-Claude Grosjean
- Web page: https://patentgrep.com/patent/US4397684A

## CPC

- C21C 5/35: Blowing from above and through the bath
- B22D 1/005: {Injection assemblies therefor (features relating to gas injection, provided on closures of the sliding gate type B22D41/42; provided on pouring nozzles B22D41/58; provided on closures of the stopper-rod type B22D41/186)}
- C22B 9/05: Refining by treating with gases, e.g. gas flushing {also refining by means of a material generating gas in situ}
- C21C: PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- B22D: CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES (shaping of plastics or substances in a plastic state B29C; metallurgical processing, selection of substances to be added to metal C21, C22)
- C22B: PRODUCTION AND REFINING OF METALS (electrolytic C25); PRETREATMENT OF RAW MATERIALS

## Abstract

A process of pneumatic stirring of a bath of molten metal according to which a stirring fluid is injected through permeable refractory elements arranged at the bottom of a crucible containing the bath, in which the used stirring fluid is, at least temporarily, an organic liquid such as hydrocarbon. The process is advantageously used on a bath of molten pig iron during refining of the same by oxygen, and in which the organic liquid is replaced immediately after decarburization of the bath by an inert gas such as argon or nitrogen. The process thus permits an efficient stirring of the bath of molten metal without the risk of polluting the metal either by hydrogen or nitrogen.

## Claims

### Claim 1

A process for pneumatic stirring during at least a part of a refinement period of a bath of molten metal in a crucible comprising the steps of injecting a stirring fluid through elements of permeable refractory material wherein the stirring fluid injected through the elements consists of an organic liquid which vaporizes upon contact with the molten metal.

### Claim 2 (depends on 1)

A process as defined in claim 1, wherein the stirring fluid is a liquid hydrocarbon.

### Claim 3 (depends on 1)

A process as defined in claim 1, wherein a short time before the end of the stirring period said organic liquid is replaced by an inert gas.

### Claim 4 (depends on 3)

A process as defined in claim 3, wherein said inert gas is argon.

### Claim 5 (depends on 3)

A process as defined in claim 3, wherein said inert gas is nitrogen.

### Claim 6 (depends on 3)

A process as defined in claim 3, wherein said bath of molten metal is a bath of molten pig iron, and including the step of blowing oxygen from the top onto the bath to decarburize the latter while injecting said organic liquid through said elements and replacing said organic liquid by said inert gas immediately at the end of the decarburization of the molten pig iron.