Methods of protecting furnace electrodes with cooling liquid that contains an additive

Patent metadata

Field	Value
Publication number	US-11653426-B2
Application number	US-202117464250-A
Country	US
Kind code	B2
Filing date	Sep 1, 2021
Priority date	Oct 15, 2018
Publication date	May 16, 2023
Grant date	May 16, 2023

Abstract

A method for forming a protective antioxidative barrier on the furnace electrodes using a chemically altered cooling liquid containing an antioxidant additive. This method can be applied to electrodes used in electric arc furnaces and ladle metallurgy furnaces. The method can involve spraying the cooling liquid onto the electrode, thereby forming the protective antioxidative barrier and reducing the oxidation of the electrode.

First claim

What is claimed is:

1. A method for protecting a furnace electrode comprising:
(i) combining at least one antioxidant additive with electrode cooling water to form a chemically modified cooling liquid;
(ii) while a portion of the furnace electrode is positioned inside a furnace and another portion of the furnace electrode is positioned above the furnace; and while electrical power is delivered to raw materials through the furnace electrode to melt the raw materials, spraying a surface of the furnace electrode above the furnace with the chemically modified cooling liquid,
(iii) while the electrical power is delivered to the raw materials through the furnace electrode and while the furnace electrode is being sprayed with the chemically modified cooling liquid, forming a coating on the furnace electrode, the coating comprising the at least one antioxidant additive, which is applied to the surface of the furnace electrode as the water evaporates from the chemically modified cooling liquid that has been sprayed on the surface of the furnace electrode while electrical power is delivered to the raw materials through the furnace electrode to melt the raw materials; and
(iv) moving the furnace electrode further into the furnace such that at least a portion of the coating formed on the surface of the furnace electrode moves into the furnace.

2. The method of claim 1 , wherein the at least one antioxidant additive has a solubility in water of at least 10 mg/L.

3. The method of claim 1 , wherein the at least one antioxidant additive has a solubility in water of at least 100 mg/L.

4. The method of claim 1 , wherein the chemically modified cooling liquid includes the at least one antioxidant in an amount in the range of from 10 mg/l to 5,000 mg/l.

5. The method of claim 1 , wherein the chemically modified cooling liquid includes the at least one antioxidant additive in an amount in the range of from 10 mg/l to 1,000 mg/l.

6. The method of claim 1 , wherein the chemically modified cooling liquid includes the at least one antioxidant additive an amount in the range of from 10 mg/l to 850 mg/l.

7. The method of claim 1 , wherein the furnace electrode is an electric arc furnace electrode or a ladle metallurgy furnace electrode.

8. The method of claim 1 , wherein at least a portion of a surface of the furnace electrode is at a temperature of at least 700° C. while electrical power passes through the furnace electrode to melt the raw materials inside the furnace and while the furnace electrode is simultaneously being sprayed with the chemically modified cooling liquid.

9. The method of claim 1 , wherein at least a portion of a surface of the furnace electrode is at a temperature of at least 1000° C. while electrical power passes through the furnace electrode to melt the raw materials inside the furnace and while the furnace electrode is simultaneously being sprayed with the chemically modified cooling liquid.

10. The method of claim 1 , wherein the at least one antioxidant additive comprises (i) one or more component selected from phosphates, phosphonates, calcium salts, magnesium salts, molybdates, boron salts, and silicates, and optionally (ii) one or more component selected from a scale inhibitor and a dispersant.

11. The method of claim 1 , wherein the chemically modified cooling liquid is constantly sprayed on the surface of the furnace electrode above the furnace while electrical power is delivered to the raw materials through the furnace electrode to melt the raw materials.

12. The method of claim 1 , wherein the chemically modified cooling liquid is sprayed on the surface of the furnace electrode disposed above the furnace at a flow rate in the range of from 0.25 m 3 /h to 10 m 3 /h.

13. The method of claim 1 , wherein the at least one antioxidant additive includes a calcium based salt.

14. The method of claim 1 , wherein the at least one antioxidant additive includes a surfactant.

15. The method of claim 1 , wherein the coating has a thickness in a range of from 0.005 to 5 mm.

16. The method of claim 1 , wherein the coating has a substantially constant thickness across the surface of the furnace electrode that is positioned above the furnace.

17. The method of claim 1 , wherein the chemically modified cooling liquid includes at least 95 wt. % water.

18. A method for protecting a furnace electrode comprising:
(i) providing a multifunctional cooling liquid that includes cooling water for the furnace electrode that has been chemically modified with at least one additive;
(ii) while a portion of the furnace electrode is positioned inside a furnace and another portion of the furnace electrode is positioned above the furnace and while electrical power is delivered to raw materials through the furnace electrode to melt the raw materials, spraying a surface of the furnace electrode that is positioned above the furnace with the multifunctional cooling liquid; and
(iii) causing a coating to form on the furnace electrode above the furnace from the multifunctional cooling liquid,
wherein the coating is effective to reduce sidewall oxidation of the furnace electrode.

19. The method of claim 18 , wherein the coating includes a transition metal salt.

20. The method of claim 18 , wherein the transition metal salt includes iron.

21. The method of claim 20 , wherein the at least one additive includes a surfactant.

22. The method of claim 1 , wherein the at least one antioxidant additive includes a transition metal component.

23. The method of claim 22 , wherein the transition metal component includes a transition metal chloride compound.

24. The method of claim 22 , wherein the transition metal component includes a transition metal nitrate compound.

25. The method of claim 22 , wherein the transition metal component includes zirconium.

26. The method of claim 22 , wherein the transition metal component includes yttrium.

27. The method of claim 1 , wherein the at least one antioxidant additive includes a polyphosphate.

28. The method of claim 18 , wherein the multifunctional cooling liquid includes from 50 mg/l to 1,000 mg/l of the at least one additive.

29. The method of claim 18 , wherein the multifunctional cooling liquid includes from 200 mg/l to 800 mg/l of the at least one additive.

30. The method of claim 18 , wherein the multifunctional cooling liquid is more than 99 wt. % water.

31. The method of claim 18 , wherein the multifunctional cooling liquid is more than 99.5 wt. % water.

Assignees

• Chemtreat Inc

Inventors

• Strasser Joseph S
• Hamnik Joseph M
• Lawson James R
• Feller Alan J

Classifications

• B05D3/002

  Pretreatement · CPC title

• F27B3/24

  Cooling arrangements · CPC title

• C09K15/02

  containing inorganic compounds · CPC title

• B05D3/0254

  After-treatment · CPC title

• Y02P10/20

  Recycling · CPC title