Method of operating an electric arc furnace and steel mill

Patent metadata

Field	Value
Publication number	US-2024191314-A1
Application number	US-202218286667-A
Country	US
Kind code	A1
Filing date	Apr 20, 2022
Priority date	Apr 20, 2021
Publication date	Jun 13, 2024
Grant date	—

Abstract

The disclosure discloses a method of operating an electric arc furnace, the method comprising capturing, from at least one facility of a steel mill, a heated metallurgical gas comprising water and carbon monoxide; conducting, by a reactor supply line, said metallurgical gas to a reactor; transforming, by a treatment of said metallurgical gas within said reactor, the carbon monoxide and water into hydrogen and carbon dioxide according to a water-gas shift reaction; and subsequently separating said hydrogen by a separation device. The method is characterized in that it further comprises providing an iron-bearing material, which comprises iron mainly in the form of iron oxide, to the electric arc furnace; at least partially melting the iron-bearing material to obtain a molten bath; conducting, by a furnace supply line, said hydrogen to the electric arc furnace, which is arranged downstream of the furnace supply line; and injecting, by a plurality of hydrogen injection devices, said hydrogen into said electric arc furnace, such that said hydrogen reacts as a reducing agent for reducing iron oxide in the molten bath during a smelting operation of the electric arc furnace.

First claim

1 . A method of operating an electric arc furnace, the method comprising:
capturing a heated metallurgical gas comprising water and carbon monoxide, from at least one facility of a steel mill; conducting said metallurgical gas to a reactor through a reactor supply line; transforming the carbon monoxide and water into hydrogen and carbon dioxide according to a water-gas shift reaction, by a treatment of said metallurgical gas within said reactor, and subsequently separating said hydrogen by a separation device; providing an iron-bearing material, which comprises iron mainly in the form of iron oxide, to the electric arc furnace; at least partially melting the iron-bearing material to obtain a molten bath; conducting said hydrogen through a furnace supply line to the electric arc furnace, which is arranged downstream of the furnace supply line; and injecting said hydrogen into the molten bath in said electric arc furnace by means of a plurality of hydrogen injection devices such that said hydrogen acts as a reducing agent for reducing iron oxide in the molten bath during a smelting operation of the electric arc furnace.

2 . The method according to claim 1 , wherein the heated metallurgical gas has a temperature in a temperature range of 20° ° C. to 100° C.

3 . The method according to claim 1 , wherein the water-gas shift reaction is performed in presence of a catalyst.

4 . The method according to claim 1 , wherein the method further comprises conducting said hydrogen via a storage supply conduct to a hydrogen storage tank and discharging said hydrogen from said hydrogen storage tank via the furnace supply line to the electric arc furnace.

5 . The method according to claim 1 , wherein the method further comprises heating said hydrogen upstream of the electric arc furnace, such that said hydrogen has a temperature in a range of 25° C. to 700° ° C. when said hydrogen is injected into said electric arc furnace.

6 . The method according to claim 1 , wherein the plurality hydrogen injection devices comprises at least one supersonic gas lance for injecting at least a part of said hydrogen supplied to the electric arc furnace into said furnace.

7 . The method according to claim 6 , wherein hydrogen injected via the supersonic gas lance has a throughput in the range of 10 m 3 /min to 500 m 3 /min.

8 . The method according to claim 1 , wherein the method further comprises injecting oxygen into the electric arc furnace through a plurality of oxygen injection devices.

9 . The method according to claim 1 , wherein the method further comprises introducing lime into the electric arc furnace by a lime introduction device.

10 . The method according to claim 1 , wherein the method further comprises inserting a material in the electric arc furnace, wherein the material comprises at least one of the following: iron oxide, pre-reduced iron ore pellets, a direct reduced iron, hot briquette iron briquettes, blast furnace grade, DR grade iron ore pellets or fines or mixtures thereof.

11 . The method according to claim 1 , wherein the method further comprises operating said electric arc furnace with electric energy obtained from a renewable energy source.

12 . A steel mill comprising an electric arc furnace and being adapted to:
capture a heated metallurgical gas comprising water and carbon monoxide, from at least one facility of the steel mill; conduct said metallurgical gas to a reactor through a reactor supply line; transform the carbon monoxide and water into hydrogen and carbon dioxide according to a water-gas shift reaction, by a treatment of said metallurgical gas within said reactor, and subsequently separate said hydrogen by a separation device; provide an iron-bearing material, which comprises iron mainly in the form of iron oxide, to the electric arc furnace; at least partially melt the iron-bearing material to obtain a molten bath; conduct said hydrogen through a furnace supply line to the electric arc furnace arranged downstream of the furnace supply line; and inject said hydrogen into the molten bath in said electric arc furnace by means of a plurality of hydrogen injection devices such that said hydrogen acts as a reducing agent for reducing iron oxide in the molten bath during a smelting operation of the electric arc furnace.

Assignees

• Wurth Paul Sa

Inventors

• Krull Jan
• PAPALIA Katia

Classifications

• F27D17/304

  specially adapted for electric arc furnaces · CPC title

• F27B3/22

  Arrangements of air or gas supply devices · CPC title

• C21B2300/02

  Particular sequence of the process steps · CPC title

• C21B13/0073

  Selection or treatment of the reducing gases · CPC title

• C21B13/0006

  obtaining iron or steel in a molten state · CPC title