IP Library Granted Patent US 12686895
Granted Patent B2
US 12686895 · App. 18/272,396 · Granted Jul 21, 2026

Method for desulfurizing molten metal

Inventor: Hidemitsu Negishi (Tokyo, JP)
Assignee: JFE STEEL CORPORATION
C21C7/064
View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 12686895
App. No.
18/272,396
Granted
Jul 21, 2026
Kind
B2
Abstract

A method for smelting cast iron, including loading charge materials, melting and introduction into the melt of vanadium, titanium and magnesium oxides and high-polymer waste compounds, characterized in that, simultaneously with the introduction of oxides and waste, the exhibit cathodic polarization of the cast iron melt at a constant current load, component 0.1-10 A/dm2 calculated on the surface of the melt mirror, while As a counter electrode, a graphite electrode with an end area of up to 0.8 is used area of the melt mirror, which is under mechanical load and under electrical under tension, immerse in slag at a distance of 30-70 mm from the surface of the melt, with In this case, the ratio of cathode and anode current densities is 0.9-1.2.

Claims (90)

1 . A method for desulfurizing molten metal that, using a direct-current power source, applies a potential difference between molten slag and molten metal through electrodes, of which one electrode contacting the molten metal serves as a negative electrode and the other electrode contacting only the molten slag serves as a positive electrode,

characterized in that an applied current density J a is determined according to an equilibrated S concentration [S] e0 before application of a potential difference such that an equilibrated S concentration [S] ea when a potential difference is applied becomes equal to or lower than a target S concentration [S] ft , wherein

the applied current density J a is set to 1000 A/m 2 or lower.

2 . The method for desulfurizing molten metal according to claim 1 ,

wherein the molten metal is molten iron, and

wherein determining the applied current density J a (A/m 2 ) involves:

step 1 of, using Formulae (1) and (2) below, determining a value of A and a value of B based on coefficients that are obtained from an equilibrated S concentration [S] e0 (mass ppm) before application of a potential difference; and

step 2 of, using Formula (3) below, calculating an equilibrated S concentration [S] ea (mass ppm) when a potential difference is applied based on the value of A and the value of B determined in step 1, and determining the applied current density J a such that the calculated equilibrated S concentration [S] ea becomes equal to or lower than a target S concentration [S] ft (mass ppm):

A

=

A

0

+

A

1

·

J

a

-

A

2

·

J

a

2

+

A

3

·

J

a

3

(

1

)

-

B

=

B

0

+

B

1

·

J

a

-

B

2

·

J

a

2

+

B

3

·

J

a

3

(

2

)

[

S

]

e

a

=

exp

(

-

B

/

A

)

.

(

3

)