JPH04110412A - Method for separating slag at the time of discharging molten iron from torpedo car - Google Patents

Abstract

PURPOSE:To perfectly and easily prevent mixing of slag into discharged molten iron by using an intermediate ladle having opening part at bottom part in intermediate between a torpedo car and a molten iron ladle at the time of discharging the molten iron from the torpedo car to the molten iron ladle. CONSTITUTION:At the time of discharging the molten iron 2 pretreated by blowing refining agent from the torpedo car to the molten iron ladle 10, the intermediate ladle 8 is used at between the torpedo car and the molten iron ladle 10. The desirable shape of this intermediate ladle 8 is funnel type or conical type having the opening part 12 at the bottom part, and the side face has 40-50 deg. inclining angle to the horizontal direction and projecting parts 14 are radially formed from the opening part 12 toward upper end part in the inside face. By this method, even if the slag 4 from the torpedo car is caused to flow out into the intermediate ladle 8, the slag is floated up on the molten iron 2 temporarily stored in the intermediate ladle 8 with difference between both sp. grs., only the molten iron 2 is poured into the molten iron ladle 10 in lower part from the opening part 12, and the slag 4 is perfectly separated.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for separating slag when hot metal is discharged from a pig iron mixing car, and particularly relates to a method for effectively separating and removing slag using a simple device and method, and is applicable to the steelmaking field. Widely used in

[Conventional technology]

When hot metal tapped from a blast furnace is received by a heavy metal car, a small amount of slab is mixed in to coat the surface of the hot metal to prevent oxidation and keep it warm. P in the pig iron mixing car before using it as
Since preliminary treatment is performed to remove S, Si, etc., scouring agents such as iron oxide powder, lime powder, and soda ash are injected for dephosphorization, desulfurization, and desiliconization. Contamination is an unavoidable phenomenon. However, if these slags are mixed into the converter at the same time as the hot metal, they will cause various problems during steelmaking, such as rephosphorization and resulfurization. It must be avoided as much as possible. Therefore, in the past, just before discharging the pig iron from the mixing car to a refining furnace such as a converter,
The sludge was removed once a month using a mechanical device such as a slag dragger, but it took about 30 minutes to remove the sludge, and it was difficult to completely remove the sludge.

Therefore, many conventional techniques have been disclosed to prevent slag from being mixed in when hot metal is discharged from a pig iron mixing car.

For example, JP-A-54-66307, JP-A-58-1.00
610, JP-A-63-21.9515, JP-A-59-2
08008, JP-A-62-1.46208, etc. The outline of these conventional techniques will be explained below.

JP-A-54-66307: This invention has a device for damming slag at the time of discharging hot metal in a pig iron mixing car, and a track is attached to a support, and a lifting frame is attached to the track to hold a gripping ring and an extrusion rod I. A movable dam rod gripping device is installed on the dam, and the slag dam rod is floated on the surface of the hot metal, and both sides of the dam rod are locked to the furnace mouth of the pig iron mixing car to dam the slag and discharge only the hot metal. It is a device.

JP-A-58-", OO610: This invention provides a sealing cover on one part of the upper opening of the Tobito Rikiichi, and a required number of slag discharge vibrators are inserted through the sealing cover so that their lower ends are inside the slag. The two ends were inserted so as to go outside the dobby car, and the combustible fluid and combustible fluid were pressurized from the combustion device inserted into the two-part space of the dobby car through the airtight cover. l-inside the speed car”
This is a method for discharging slag inside a torpedo car, which is characterized by burning it in a part of the space.

JP-A No. 63-21951.5: This invention comprises a slag stopper consisting of a frame that straddles the top of a furnace or a pot of a pig iron mixer, and a stopper body suspended from the lower surface of this gnome. The substantially C-shaped hanging footer of the above-mentioned gnome is inserted into the bottle bracket 1- provided at the furnace mouth or the outer periphery of the pot, and the holder is engaged with the bottle bracket 1- to attach the gnome to the pig iron mixer or the pot. Furnace lid type slugs in which the two-part topper body is freely engaged with the v-shaped guide hole on the gnome side of the furnace [1 or the support bins at both ends of the body parallel to the tilting center of the pot, respectively] 1 Hepper It is a device.

JP-A-59-208008 = This invention provides a magnetic flux type hot metal detector next to one part of the 1if opening of the pig iron mixer, and tilts the mixer car while measuring the hot metal I novel with the detector, so that the hot metal flows between the mixer cars [1 This is a method for removing slag from a pig iron mixer truck, which is characterized by stopping tilting and removing the slag just before leaving the section.

JP-A-62-146208: This invention provides a gas header rotatably supported by a support stand that is detachably installed across a hot metal discharging port on a pig iron mixing car, and connected to a pressure gas supply source. A slag stove bar for a mixed pig iron vehicle, characterized in that a nozzle for gas injection is provided, and a balance weight is provided on the gas rudder for keeping the gas injection angle of the nozzle constant.
The purpose is to prevent the slab from flowing out by the injection pressure of the pressurized gas that is always injected at a constant injection angle from the gas injection nozzle toward the hot water level in the pig iron mixing car.

These conventional techniques have the following problems.

(a) Each method requires large-scale and complicated equipment, and the operation of slag stove bars and the like is not easy.

(b) By leaving slag in the pig iron mixer car, the amount of hot metal charged in the pig iron mixer car decreases.

(c) There is a possibility that the slag left in the pig iron mixing car will cause residual hot metal to re-phosphorize and resulfurize.

[Problem to be solved by the invention]

The purpose of the present invention is to prevent slag from being mixed into hot metal when hot metal is discharged from a mixing car; The purpose of the present invention is to provide an effective slag separation force method that can reduce the slag separation force.

[Means to solve the problem]

The gist of the present invention is as follows. That is, (1) A method for separating slag when hot metal is discharged from a pig iron mixing car, characterized in that the hot metal is hit without being discharged from the pig iron mixing car to the hot metal ladle, and an intermediate ladle with an open bottom is interposed between the hot metal mixing car and the hot metal ladle. .

(2) The intermediate pot has a funnel-shaped side surface having an inclination angle of 40 to 50 degrees with respect to the horizontal direction, and has protrusions radially extending from the open bottom part toward the top end on the inner surface.
1) Slab separation method when discharging molten iron from a pig iron mixer car,
It is.

Embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a side sectional view showing a situation in which hot metal contained in a pig iron mixing car is being discharged into a hot metal ladle via an intermediate ladle according to the method of the present invention. In other words, hot metal 2 tapped from the blast furnace is
Together with a small amount of slag 4A from the blast furnace, it is stored in a pig iron mixer car 6 and transported to a converter factory. On the way, refining agents such as iron oxide powder, quicklime powder, and soda ash are passed through a lance together with inert gas such as N2. The hot metal 2 is blown into the hot metal 2 for preliminary treatment. In this way, a small amount of mixed slag 4 from the blast furnace is present on the surface of the hot metal 2 which has been pretreated by dephosphorization, desulfurization, desiliconization, etc.
In addition to A, the slab 4B generated by the preliminary treatment is also added to form the normal mixed slag 4.

However, the pretreatment of the hot metal 2 is usually carried out in two to three stages because dephosphorization and desiliconization are fermentation reactions, but desulfurization is a reduction reaction. At this time, if the slag generated in the pre-processing is left as it is without being drained, it may cause problems in the next preliminary processing. In particular, if the slab after dephosphorization treatment is left as it is, the P in the slag will be reduced by unreacted refining agents and the like, causing a so-called rephosphorization phenomenon, so it is necessary to remove the slag immediately. In addition, it is necessary to remove desulfurization and desiliconization slag before charging the hot metal 2 into the converter. Most preferred from ten.

The method for separating slabs when discharging molten iron from a pig iron mixer car according to the present invention is characterized by the interposition of an intermediate ladle 8, as shown in FIG. A preferred form of the intermediate pot 8 is shown in FIGS. 1 and 2 (A
, ), (B) as follows.

(a) It has a funnel shape or a forest shape with an open CI section 12 at the bottom, and its side surfaces have an inclination angle of 40 to 50 degrees with respect to the horizontal direction.

(b) The inner surface thereof has protrusions 14 radially extending from the opening 2 to the upper end.

In this way, even if the slag 4 is floating on the surface of the hot metal 2 stored in the pig iron mixer 6, the hot metal 2 stored in the pig iron mixer 6 is initially injected into the intermediate ladle 8 by tilting the pig iron mixer 6. , push the slag 2 that has flowed out into the furnace port 16 of the pig iron mixer 6 into the intermediate ladle 8.
As long as you are careful not to inject it into the
Even if the slag 4 flows into the intermediate ladle 8, due to the difference in specific gravity, it floats on the hot metal 2'' temporarily stored in the intermediate ladle 8, and only the hot metal 2 is in the hot metal ladle 10 below from the opening 1-2. is injected, and the slag 4 is completely separated.

[For production]

Normally, the slag 4 floating on the pre-treated hot metal 2 of the pig iron mixing car 6 is
Since the intermediate pot 8 has a property of having low viscosity and being easily agglomerated, a third protrusion 84 is formed on the inner surface of the intermediate pot 8 from the central opening 1 12 radially toward the second end. As shown in the enlarged view, when the slag 4 with low viscosity comes into contact with the upper protrusion 4 of the intermediate pot 8, the slag 4 has a characteristic of minimizing the contact area, so the slag 4 is placed in the recess between the protrusions 14. 4 does not flow in, leaving a hollow portion] 8. As a result, most of the slag 4 in the intermediate ladle 8 after pouring the hot metal 2 from the mixer car 6 into the hot metal ladle 10 is solidified, and the slag 4 remaining near the opening 12 is also almost solidified. Since it stops flowing, the hot metal passes through the opening [1 part]-2 and is poured into the hot metal pot 1.
There is no flow toward 0. Moreover, when cleaning and discharging the solidified slag 4 remaining in the intermediate pot 8, the protrusion 1
Since the 4th part between 4 and 4 is left blank and the hollow part 8 is left,
This hollow part 181. By inserting a round bar or the like, the residual slag 4 can be easily peeled off and removed. In order to maximize the above two effects, the angle of inclination of the inner surface of the intermediate pot 8 with the horizontal direction is limited to 40 to 50 degrees, and the maximum effect is not achieved at an angle of -1-2 below. I can't perform.

Furthermore, by providing the protruding parts 4 radially from the opening 12 to the two ends of the intermediate ladle 8, the hot metal 2 poured into the intermediate ladle 8 follows the four grooves between the protruding parts 14, There is also the effect that the hot metal quickly flows down and is injected into the hot metal ladle 10 provided below through the opening]-2. Note that the protrusion 1
The shape of the groove between the grooves 4 may be either U-shaped or U-shaped, and can be set so as to form the hollow portion 18 in consideration of the viscosity of the slag 4.

〔Effect of the invention〕

When separating the slag when hot metal is discharged from the pig iron mixer car according to the present invention, a forest-like or funnel-shaped intermediate pot having an opening at the lower end is arranged between the pig iron mixer car and the hot metal ladle, and Protrusions are formed radially from the opening to the upper end,
Since we adopted a method of discharging the hot metal to the lower ladle via this intermediate ladle, we were able to achieve the following effects.

(b) The slag separation device and its separation operation according to the present invention are extremely simple and easy to operate compared to conventional methods or devices, so the equipment cost is relatively low, and the slag separation device and its separation operation are extremely simple and easy to operate, compared to conventional methods or devices, so the equipment cost is relatively low, and the slag separation device and its separation operation are very simple and easy to operate. We were able to shorten the operating time until furnace charging.

(0) Conventionally, it took about 30 minutes to remove the slag from the hot metal mixer car just before charging into the converter, but the present invention eliminates the need for this slag removal work, allowing the removal of hot metal from the conventional pig iron mixer car. Hot metal discharge,
The operating time until charging the converter was shortened.

(c) Compared to conventional slag removal work, where slag could not be completely removed and a small amount of slag remained, the method of the present invention can almost completely separate and remove slag, so it can be installed in a converter. The reliability of the weight of molten iron charged into the converter has increased, and whereas conventionally the amount of molten iron in one charge of the converter was 3001, the error was 3 tons, with the method of the present invention, the error was 0, and depending on the accuracy of the operating raw materials, , the component accuracy of refined steel grades was significantly improved.

Based on the results of (d) and (c), P
In contrast to the average IQppm of implant l-, the input of P due to slag by the method of the present invention is lpp
It was possible to reduce the number to m.

[Brief explanation of the drawing]

FIG. 1 is a schematic side sectional view showing the arrangement of a device in an embodiment of the present invention for separating slag during discharging hot metal from a pig iron mixing car;
2 (A,) and (B) show the intermediate pot used in the present invention, (A) is a side sectional view, (B) is a perspective view showing the inner surface,
FIG. 3 is an enlarged partial sectional view showing the state of contact between the protrusion and the slug in the intermediate ladle. 2...Hot metal 4...Slag 6...
Mixed railway car 8...Intermediate ladle 10...Hot metal ladle ]-2...Opening 14...Protrusion
]6...Pig car furnace mouth 18...Hollow part

Claims (2)

[Claims] (1) A method for separating slag at the time of discharging hot metal from a pig iron mixing car, characterized by interposing an intermediate ladle with an open bottom between the pig iron mixing car and the hot metal ladle when discharging hot metal from the pig iron mixing car to the hot metal ladle. (2) The intermediate pot has a funnel-shaped side surface having an inclination angle of 40 to 50 degrees with respect to the horizontal direction, and has a protrusion radially extending from the bottom opening toward the top end on the inner surface. The method for separating slag when discharging hot metal from a pig iron mixing car as described in (1).