Steel production from iron melt

Patent metadata

Field	Value
Publication number	US-2024052442-A1
Application number	US-202118250928-A
Country	US
Kind code	A1
Filing date	Oct 28, 2021
Priority date	Oct 30, 2020
Publication date	Feb 15, 2024
Grant date	—

Abstract

A process for steel production that includes:
production of sponge iron from iron oxide-containing starting material by direct reduction with reduction gas, wherein the reduction gas has at least 20% by volume of hydrogen H 2 , and production of an iron melt having a carbon content of 1-5% by mass from the sponge iron.

Sponge iron is subjected to a treatment that includes:
energy input and addition of additives to produce a melt and a slag, wherein the energy input is effected substantially from electricity and wherein the slag has a basicity B2 of less than 1.3, preferably less than 1.25, particularly preferably less than 1.2, adjustment of the carbon content in the melt, reduction of at least a sub-amount of the iron oxides present in the sponge iron

The slag is separated during and/or after the treatment.

First claim

1 . A process for steel production comprising
production of sponge iron from iron oxide-containing starting material by direct reduction with reduction gas, wherein the reduction gas comprises at least 20% by volume of hydrogen H2, and production of an iron melt having a carbon content of 1-5% by mass, wherein at least a sub-amount of the sponge iron produced from iron oxide-containing starting material by direct reduction with reduction gas is subjected to a treatment, wherein the treatment comprises: energy input and addition of additives to produce a melt and a slag wherein the energy input is effected substantially from electricity and wherein the slag has a basicity B2 of less than 1.3, preferably less than 1.25, particularly preferably less than 1.2, adjustment of the carbon content in the melt, reduction of at least a sub-amount of the iron oxides present in the sponge iron and wherein the slag is separated during and/or after the treatment and use of the iron melt for production of steel.

2 . The process as claimed in claim 1 , wherein the direct reduction is performed using a reduction gas comprising more than 45% by volume of hydrogen H2.

3 . The process as claimed in claim 1 , wherein the direct reduction is carried out in a direct reduction reactor the treatment is carried out in a treatment reactor and the direct reduction reactor and the treatment reactor are spatially separate from one another.

4 . The process as claimed in claim 1 , wherein the energy input is effected via an electric arc.

5 . The process as claimed in claim 1 , wherein the energy input is effected via electric resistance heating.

6 . The process as claimed in claim 1 , wherein the energy input is effected via a hydrogen plasma produced using electricity.

7 . The process as claimed in claim 1 , wherein the energy input is effected partly via introduction of oxygen
for gasification of carbon supplied to the melt in the solid or liquid state or of carbon dissolved in the melt.

8 . The process as claimed in claim 1 , wherein
the adjustment of the carbon content in the melt is effected using supplied carbon carriers.

9 . The process as claimed in claim 1 , wherein
the adjustment of the carbon content in the melt is effected using supplied oxygen.

10 . The process as claimed in claim 1 , wherein the reduction of at least a sub-amount of the iron oxides present in the sponge iron is effected using supplied carbon carriers.

11 . The process as claimed in claim 1 , wherein the reduction of at least a sub-amount of the iron oxides present in the sponge iron is effected using carbon present in the sponge iron.

12 . The process as claimed in claim 1 , wherein the reduction of at least a sub-amount of the iron oxides present in the sponge iron is effected at least partly using electric current.

13 . The process as claimed in claim 1 , wherein the treatment effects a lowering of the melting range using supplied solid carbon carriers and/or liquid carbon carriers and/or gaseous carbon carriers.

14 . The process as claimed in claim 1 , wherein the production of steel employs the LD/BOF process.

Assignees

• Primetals Technologies Austria GmbH

Inventors

• Millner Robert
• Rein Norbert
• Wurm Johann

Classifications

• C21B13/14 Primary

  Multi-stage processes {processes carried out in different vessels or furnaces} · CPC title

• C21B13/0073

  Selection or treatment of the reducing gases · CPC title

• C21C5/5205

  in a plasma heated furnace · CPC title

• C21B13/143 Primary

  Injection of partially reduced ore into a molten bath · CPC title

• C21C7/072 Primary

  Treatment with gases (C21C7/06, C21C7/064, C21C7/068 take precedence) · CPC title