JPS60238407A - Casting bed desiliconizing method of molten iron - Google Patents

Abstract

PURPOSE:To carry out casting bed desiliconization with high treating effect by branching a treating agent charge means into the inside and the outside of a dust collecting hood, charging the agent from the outside at the beginning, and changing over the charge to the inside when the circulation in a trough becomes obstructed. CONSTITUTION:In casting bed desiliconization, a treating agent 7 is firstly charged from a charge chute 5'' provided at the outside of a dust collecting hood 4, and an inside chute 5' is closed with a damper 10. Since the treating agent 7 is charged into molten iron 6 at a distance from the leading end 11 of a trough, the treating agent 7 is never sucked into the dust collecting hood 4. When slag 8 begins clogging a trough 1, the treating agent 7 is charged from the inside chute 5' by changing over the damper 10. Accordingly, since the treating agent 7 is charged at the leading end 11 of the trough, a hood 12 at the leading end is provided in the hood 4 to prevent the loss of the treating agent 7 due to suction into the hood 4. When the circulation in the trough 1 returns to normal, the agent is again charged from the outside chute 5''.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an effective method for introducing a treatment agent when desiliconizing hot metal near the tip of a hot metal gutter.

(Prior Art) Currently, there are many methods of pre-treating hot metal before sending it to the steel-making process to reduce the unit consumption of treatment agents in the steel-making process. In that case, the preliminary treatment is, for example, as known from Tokai Kaisho No. 56-217, by injecting a hot metal treatment agent into the hot metal flow being led to the pig iron mixing car or pig iron receiving ladle, without using a special reaction tank. It makes the most sense from an economic and processing power standpoint to do so. Therefore, conventional attempts have been made to introduce a hot metal treatment agent into the hot metal flow from a treatment agent input sheet in an open state as shown in FIGS. 2 and 8.

In these figures, 1 is a hot metal trough, 2 is a tilting trough, 3 is a mixed iron car,
4 is a dust collection hood, and 5 is a processing agent input sheet. In Fig. 2, the treatment agent 7 is poured into the surface of the flowing hot metal 6 from the treatment agent input sheet 5 in an open state in the middle of the hot metal sluice l. The slag 8 and the like produced by the reaction adhere to the side surfaces of the hot metal sluice 1, and the grown super-reacted shark products clog the molten metal sluice 1, which has the drawback of requiring equipment such as a slag scraping device. In addition, in order to solve this drawback, the processing agent injection chute 5
As shown in Fig. 8, the place where the hot metal is poured is changed from the place where the hot metal falls from the pouring gutter 1 to the tilting gutter 2, and the treatment agent 7 is added to the hot metal 6.
Normally, there is a device 4 at this charging position to prevent dust generation when the hot metal 6 falls into the tilting trough 2 so as to cover the charging chute 5. The present invention has the disadvantage that the fine-grained processing agent 7 in the input processing agent is sucked and the loss of the processing agent 7 increases. The purpose is to provide a highly effective method of introducing the processing agent 7.

(Structure and operation of the invention) When performing desiliconization treatment of hot metal near the tip of a hot metal gutter, the present invention provides a treatment agent injection means that can be switched to the inside and outside of the dust collection hood, and The agent is mainly injected using the treatment agent input means outside the dust collection hood, and if the flow in the gutter becomes poor due to a reaction of the input treatment agent, the agent is switched to the treatment agent input means inside the dust collection hood. The details of the method for desiliconizing a hot metal casting bed will be described below using illustrated examples.

FIG. 1 shows an example of the means used when carrying out the method of the present invention, in which the means for introducing the processing agent 7 is as follows:
Inject the processing agent into the inside and outside of the dust collection hood 4, respectively.
-) 5' and 5'' are provided by branching into two.

The processing agent 7 is fed by a conveyor 9, and these bifurcated processing agent input chutes 5' and 5'' are provided with dampers IO, so that the chute to be used can be switched at any time. ing.

That is, at the start of the process, first, since the charging chute 5'' provided outside the dust collection hood 4 is used, the damper 10 closes the charging chute 5' side.

Therefore, the treatment agent 7 is introduced into the hot metal 6 at a position outside the dust collection hood 4, that is, at a position farther from the gutter tip 11.

During this time, there is no fear that the processing agent 7 will be sucked into the dust collection hood 4.

However, as time passes, the slag 8 begins to block the hot metal trough 1. If the flow starts to become poor due to slag, etc., switch <-io, close the input chute 5'' in use, and open the input chute 5' located inside the dust collection hood 4.Insertion position Processing agent 7 in which was switched
is thrown in at the gutter tip 11.

Therefore, in this case, since there is a possibility that the processing agent will be sucked into the dust collecting hood 4, the gutter tip hood 12 is disposed at least in the dust collecting hood 4 at an upper position near the gutter tip 11. Just providing this gutter tip hood 12 has the effect of significantly preventing suction loss of the processing agent 7 to the dust collecting hood 4.

On the other hand, the poor circulation caused by the slag 8 that occurred in the hot metal sluice 1 downstream of the input seam 5" will gradually improve as no additional treatment agent is added, and eventually return to normal condition. Then, the damper 10 is switched again, the charging chute 5' is closed, and the charging chute 5'' outside the dust collecting hood 4 is opened to continue charging the processing agent.

In this way, by selectively using the input shoots depending on the conditions inside the gutter, it is possible to maintain the most preferable treatment condition at each point in time during operation. When receiving hot metal of 0 torpedo car K 250), a desiliconizing agent consisting of mill scale and iron sand was added to the hot metal gutter at a rate of 3 per ton of hot metal.
The means for introducing the desiliconizing agent °, in which 5 and 7 were continuously introduced, was a two-pronged chute as shown in Figure 1. It is located at a distance of K 1.5 m from the upstream end of the hood. At the beginning of charging, the hot metal was first charged from this outside charging chute, and when an abnormality was observed in the flow of hot metal when approximately 60 inches were charged, the molten pig iron was switched to Danno<- and the hot metal was charged from the inside charging seat of the dust collection hood. . With this shot 10
When I continued to put in the chute, the abnormality was resolved, so I switched to the outside chute again and put in the final 30%.

(Effects of the Invention) According to the present invention, approximately 32 tK of desiliconizing agent is sucked out from the conventional dust collection hood, and by carrying out the present invention, it is possible to reduce the amount of desiliconizing agent that was wasted to 16% K. Therefore, the industrial effect is extremely large.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the implementation status of the present invention, and Figs. 2 and 3 are explanatory diagrams showing the conventional method. ...Dust collection hood 5'/Treatment agent input sheet 5'' inside the dust collection hood Treatment agent input chute 6 outside the dust collection hood...Hot metal 7.
...Treatment agent 8...Slag 9...Conveyor 10...Damper 11...Gutter tip 12...Gutter tip hood Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] When desiliconizing hot metal near the tip of the hot metal gutter, a treatment agent injection means is provided so that it can be switched between the inside and outside of the dust collection hood, and the treatment agent is mainly input into the dust collection hood. Molten iron is carried out using an external processing agent input means, and if the flow rate in the gutter becomes defective due to the reaction of the input treatment agent, the process is switched to the treatment agent input means inside the dust collection hood. Casthouse desiliconization method.