Molten iron refining method and device thereof

Patent metadata

Field	Value
Publication number	US-2016186277-A1
Application number	US-201314910771-A
Country	US
Kind code	A1
Filing date	Sep 25, 2013
Priority date	Aug 7, 2013
Publication date	Jun 30, 2016
Grant date	—

Abstract

Provided are a molten metal refining device and method. The molten metal refining method includes: preparing molten metal; dipping an impeller into the molten metal; supplying a liquid dephosphorization agent on top of the molten metal; and stirring the molten metal by rotating the impeller, wherein a solid dephosphorization agent in a powder state is supplied through the lower portion of the impeller in the stirring of the molten metal, thereby improving the stirring efficiency of the molten metal and efficiently controlling the phosphorus concentration in the molten metal.

First claim

1 . A device for refining molten metal, comprising:
an impeller extending in a vertical direction over a ladle in which the molten metal is charged; and a liquid dephosphorization agent supply part disposed over the ladle to supply a molten state liquid dephosphorization agent to a top portion of the molten metal, wherein the impeller comprises:
an impeller body;
blades provided on an upper outer circumferential surface of the impeller body;
a supply pipe which is disposed inside the impeller body along a lengthwise direction of the impeller body and through which a solid dephosphorization agent in a powder state and a transfer gas are supplied; and
blowing nozzles partially passing through a lower portion of the impeller body and communicating with the supply pipe.

2 . The device of claim 1 , wherein the blades are positioned above approximately the midpoint of a total depth of the molten metal, and the blowing nozzles are positioned under approximately the midpoint of the total depth of the molten metal.

3 . The device of claim 2 , wherein the blades are disposed in a region of approximately 10% to approximately 30% with respect to a total depth of the molten metal from a molten metal surface of the molten metal.

4 . The device of claim 1 , wherein the liquid dephosphorization agent supply part is connected to a discharge pipe provided with a heater to heat the liquid dephosphorization agent.

5 . The device of claim 1 , wherein the blades have upper widths formed greater than lower widths.

6 . The device of claim 5 , wherein the upper widths of the blades are formed greater than the lower widths of the blades by approximately 5% to approximately 20% of total lengths of the upper widths.

7 . The device of claim 6 , wherein the blades are formed to have widths of approximately 35% to approximately 45% to an inner diameter of the ladle.

8 . The device of claim 6 , wherein the blades are provided in plurality and spaced apart from each other about the impeller main body, and inclined surfaces are formed on at least one side surface facing an adjacent blade.

9 . The device of claim 7 , wherein the one side surface of the blade is formed to have an angle of approximately 10° to approximately 30° with respect to an upper surface of the blade.

10 . A method of refining molten metal, the method comprising:
preparing molten metal; dipping an impeller into the molten metal; supplying a liquid dephosphorization agent to an upper portion of the molten metal; and stirring the molten metal by rotating the impeller,
wherein a solid dephosphorization agent in a powder state is supplied through a lower portion of the impeller during the stirring of the molten metal.

11 . The method of claim 10 , wherein slag generated from a previous process is removed before the dipping of the impeller.

12 . The method of claim 11 , wherein in the dipping of the impeller, blades of the impeller are disposed above approximately the midpoint of a total depth of the molten metal, and blowing nozzles of the impeller are disposed under approximately the midpoint of the total depth of the molten metal.

13 . The method of claim 12 , wherein the blades of the impeller are disposed in a region of approximately 10% to approximately 30% from a molten metal surface of the molten metal.

14 . The method of claim 10 , wherein the stirring comprises stirring the molten metal such that a direction of a stirring flow of the molten metal generated from blades of the impeller coincides with a direction of a stirring flow of the molten metal generated by the solid dephosphorization agent blown into the molten metal.

15 . The method of claim 14 , wherein the stirring flow generated from the blades flows to be separated into upward and downward directions, and an area of the stirring flow of the molten metal in the downward direction from the blades is greater than an area of the stirring flow of the molten metal in the upward direction from the blades.

16 . The method of claim 10 , wherein the liquid dephosphorization agent supplied to the molten metal is approximately 50 wt % to approximately 70 wt % with respect to a total weight of the liquid and solid dephosphorization agents.

17 . The method of claim 16 , wherein in the supplying of the solid dephosphorization agent, an inert gas is supplied together with the solid dephosphorization agent.

18 . The method of claim 17 , wherein the slag is removed after the stirring of the molten metal.

Assignees

• Posco

Inventors

• Park Jung Ho
• Kang Soo Chang
• Chun Jin Kyu
• Seo Yun Yeol

Classifications

• C21C1/025

  Agents used for dephosphorising or desulfurising · CPC title

• C21C7/0645

  Agents used for dephosphorising or desulfurising · CPC title

• C21C1/02 Primary

  Dephosphorising or desulfurising · CPC title

• F27D27/00

  Stirring devices for molten material (charging or discharging liquid or molten material F27D3/14) · CPC title

• C21C1/06

  Constructional features of mixers for pig-iron · CPC title