Surging molten iron slag-off method

Abstract

The invention provides a surging molten iron slag-off method. Two air injection guns are perpendicularly inserted into molten iron from the top of a molten iron tank. The interval between the two guns is 1 / 2 of the radius of a tank opening, the insertion positions are located at the points 1 / 2 of the radius of the tank opening, and the insertion depth ranges from 0.5 m to 2.5 m; the air supply intensity is controlled to be larger than or equal to 2 NL / (min t) and the pressure is larger than 0.7 MPa; the air supply intensity of the air injection gun A is controlled to be 2 NL / (min t), the air supply intensity of the air injection gun B is gradually increased till the molten iron boiling exposed face makes contact with the wall of the molten iron tank, the air supply intensity of the air injection gun A is adjusted to be the same as that of the air injection gun B till the area of the molten iron boiling exposed face is larger than 1 / 2 of the tank opening of the molten iron tank, and therefore slag-off operation is started; after slag-off operation is finished, the air injection guns are pulled out of the molten iron and inject air continuously for over 30 s; and hoist cranes are used for lifting the air injection guns, so that locating pins are away from locating holes from 190 mm to 210 mm, the hoist cranes are transversely moved till the interval between the two guns reaches the length of the radius of the tank opening and then the hoist cranes fall, and the locating pins fall into new locating holes. By the adoption of the surging molten iron slag-off method, slag-off time can be shortened and iron loss and the converter resulfurization amount generated in the desulfuration slag-off process can be effectively reduced.

Description

technical field [0001] The invention belongs to the technical field of slag removal from molten iron tanks, and particularly relates to a kind of method that does not use a slag accumulating agent after desulfurization, desiliconization and dephosphorization of molten iron, but utilizes the phenomenon of springing formed by blowing gas from an air jet gun to push the top slag of the molten iron tank to The slag removal port is easy to remove the slag and reduce the loss of molten iron. Background technique [0002] After desulfurization, dephosphorization, and desiliconization of molten iron, in order to prevent problems such as "returning sulfur" and "returning phosphorus" in subsequent processes, and increasing metallurgical lime consumption, it is necessary to remove the top slag after the third desulfurization of molten iron. In order to remove the top slag smoothly, the current conventional method is to put in a slag accumulator to make the top slag with good fluidity v...

AI Technical Summary

Problems solved by technology

The jet gun of this method is also inserted into the molten iron obliquely, which inevitably produces a certain deflection, resulting in micro-cracks in the refractory material on the upper surface of the jet gun under the action of tension, which accelerates the erosion of molten iron and shortens the life of the jet gun

Moreover, the spray gun cannot move left and right in the horizontal direction during the slag removal process, so that at the end of slag removal, that is, when the amount of residue is less than 1 / 5 of the total amount of slag, it is difficult to gather the residue to the Together, and the gas supply intensity exceeds a certain value, it will cause the risk of molten iron splashing

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