JPS59185719A - Slag-off method in converter having bottom blowing installation - Google Patents

Abstract

PURPOSE:To permit quick and automatic slag raking operation by blowing the gas jet flow from a bottom blowing tuyere onto the surface of a slag bath through a baffle plate which is fixed at the top end of a supporting bar and has the angle directed to the discharging direction of the slag. CONSTITUTION:A converter 1 after completion of blowing is tilted forward and after the converter is held approximately in a horizontal position, a baffle plate 3 which is fixed at the top end of a support bar 3' and has the angle alpha directed in the discharging direction of the slag is inserted into the converter. A changing door 2 is then closed. The jet flow of inert gas is then ejected through a tuyere 4 so as to collide against the plate 3, by which the gas is blown onto the bath surface of slag 5. The gas provides flowing to the slag 5 thereby discharging the slag into a slag carriage 8. A heat insulating material is used on the outside of the bar 3 and cooling air is fed in the inside.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a slag removal method in a converter equipped with bottom blowing equipment, in which a gas jet stream ejected from the bottom blower is made to collide with a baffle plate and sprayed onto the slag bath surface. This relates to a slag removal method characterized by pouring out slag.

In the converter manufacturing method, a large amount of blast furnace slag is suspended on the surface of the hot metal sent from the blast furnace to the center.

If the steel is charged into the converter as it is and blowing is performed, there are many problems such as an increase in the amount of slag. Conventionally, the slag was removed by using a slag drag or the like to remove the slag when the hot metal was charged into the ladle, but this process took more than 5 minutes and was time-consuming. Due to its nature, it is difficult to automate, which has been a bottleneck in efforts to save labor.

The purpose of the present invention is to perform this oyster oyster work quickly and automatically by using the bottom-blown gas of a converter equipped with bottom-blowing equipment.

One example of the embodiment of the present invention will be explained below. FIG. 1 is a sectional view of one example of an embodiment of the present invention. 1 is a converter furnace body that has been tilted to a nearly horizontal position for sludge removal. This is a shielding wall (hereinafter referred to as a charging door) to prevent the slag from scattering.

Gas jet 7 from 3-bottom blowing tuyere 4, r-nurag surface K
(2) It is a baffle plate that allows you to face the direction. 5-ke slug.

6 is the hot metal or molten steel, and 8 is the slag truck that receives the removed slag. The baffle plate 3 is set at an angle α that allows the gas jet from the tuyere 4 to efficiently discharge the slag.

The insertion and ejection of the jammer plate 3 is performed by mechanical force through a gap provided in the charging door. Further, it is preferable that the support rod portion 3' of the jammer plate 3 is heat-insulated using a heat insulating material and the inside thereof is air-cooled. FIG. 2 shows an example of a baffle plate used to air-cool the inside of the support rod. Cooling gas for air-cooled jammer plates.

In the case of air, a sufficient cooling effect can be obtained at about 2Nrn/min.

The embodiments of the present invention will be further described with reference to Examples.

Example After blowing 250 under normal conditions, the converter 1 was tilted in front of the furnace, held in a horizontal position, and a jammer plate was inserted.
Close the charging door.

Slag removal was carried out by flowing N gas from the bottom blowhole at a rate of 100 NrnA'nin. The angle of the jammer plate is 25 to 30 degrees from the horizontal plane, and 80 to 90
% of the slag was taken out of the furnace and transferred to the slag pot. Comparing this with the conventional method (double tapping method), the temperature loss was about 20% smaller and the process time was about 20 minutes shorter.

In addition, in the case of blowing ultra-low P steel, it is necessary to remove slag during the blowing process, so the fluidity of the slag is worse than that at the end of normal blowing (about 5 minutes of removal). Although it takes time to process the slag, the slag removal can be carried out more efficiently by gradually moving the insertion position of the jammer plate into the converter furnace from the furnace bottom side to the furnace mouth side during the slag removal process. It was possible to shorten the f'Ivc treatment time to about 4 minutes.After the slag removal was completed, the secondary process of ultra-low P blowing was carried out to achieve the target P concentration of 0. 0
We were able to perform all melting processes with extremely low P'A of less than 10%.

[Brief explanation of the drawing]

FIG. 1 is a knock-proof view of one example of the inventive embodiment, and FIG. 2 is a partially enlarged view of an air cooling jammer plate. Code 1...Converter furnace body 2...Working floor 3...Block plate ・3' River...Budger plate support rod 4... Bottom blowing tuyere 5...Slag 6.
...Hot metal welding 7...-Working floor 8...Slag cart Patent applicant Kawasaki Steel Co., Ltd. Representative Patent attorney Yoshikatsu Matsushita License exchanger Fumio Soejima Figure 7 Figure 2

Claims (1)

[Claims] In order to remove slag floating on molten metal by tilting a converter equipped with a bottom blowing surface until the axis of the converter is approximately horizontal, 2. A barrier plate fixed to the tip of the support rod and oriented at an angle in the slag discharge direction is placed so as to face the slag bath surface in the converter. Ganuzietsu Ha ejected from the bottom blowing surface collides with the jammer plate and is sprayed onto the slag bath surface. A slag removal method using a bottom-blown slag jet in a converter equipped with a bottom-blowing tuyere, characterized in that tjTtfl is imparted to the slag.