JP4580435B2 - Forming sedative material for slag pan and sedation method - Google Patents

Description

The present invention relates to a forming sedative material for a slagging pan slag that is forming (foaming) and a method for sedating the same.

Steelmaking slag generated in the process of producing molten steel (hereinafter simply referred to as slag) foams (ie, forms) due to CO bubbles generated at the interface with the molten iron or inside the slag itself during or after the refining process (ie, slag). In a severe case, the slag volume may expand, and if it is severe, it may overflow from a refining facility such as a converter, a kneading car, a waste pan, or a molten iron or slag transfer container. Since this slag has a high temperature of 1300 to 1650 ° C., it overflows and damages the equipment, and a great deal of time and labor is required for its recovery.
As a method of avoiding such overflow of slag, for example, there is a method of reducing the speed of the refining process, or a method of temporarily interrupting the refining process, but these are adversely affecting productivity and are preferable methods. I can't say that.

In the above-mentioned CO bubble generation process, FeO (iron oxide) in slag and C in molten iron react at the interface, and similarly, FeO in slag and C in granular iron contained in the slag react. There are two cases. However, in any case, the longer the time (life) from the arrival at the surface of the slag to the burst, the easier the bubbles stay in the slag. In addition, since the bubble is stably present in the slag as the diameter thereof is smaller and the viscosity of the slag component is higher, the lifetime of the bubble is prolonged (it is difficult to burst).
From the above, in order to suppress the expansion of the slag, the coalescence of fine bubbles may be promoted and coarsened.

Thus, carbon powder is known as a substance that promotes coalescence of fine bubbles and coarsens them.
For example, Patent Document 1 discloses a sedation method in which carbon powder (carbon material) is sprayed on a forming slag at a rate of 5 to 100 kg / min.
Further, in Patent Document 2, carbon powder (carbon material) having a particle diameter of 0.1 to 1 mm and 1 to 5 mm is blown from an independent blowing system, and the amount of blowing is subjected to one suppression operation, and the hot metal 1 A sedation method is disclosed in which 0.1 kg or more and less than 0.8 kg per ton and a blowing speed of 5 to 100 kg / min are disclosed.

Also, in recent years, when refining hot metal to make molten steel, after dephosphorizing in the converter, part of the slag in the furnace is discharged into the waste ladle installed under the furnace, followed by decarburization. The method (multifunctional converter method) has been carried out.
In this method, by adjusting the CaO / SiO ₂ ratio (hereinafter referred to as basicity) of the slag component to 0.8 to 1.5 in the converter, the viscosity of the slag is increased to facilitate the forming of the slag. The discharge is good.
The slag as described above discharged from the converter has a fine bubble diameter and high viscosity of the slag, so that it is easier to form immediately after being discharged into the discharge pan. In addition, once the forming is subdued, it is easy to form continuously by the slag discharged one after another.

Therefore, in order to discharge such slag in a large amount in a short time from the converter while preventing overflow of the slag from the waste pan, the forming in the waste pan can be calmed down. The effect of the sedative that suppresses forming is an important point.
Here, when the effect of the sedative material is small, it is necessary to reduce the amount of waste in order to avoid the overflow of the slag, It is easy to cause slopping. Moreover, in order to suppress this rephosphorization and slopping, the amount of CaO used may be increased. However, in this case, the amount of slag having a high CaO concentration is increased, and not only the refining cost but also slag is increased. It is not preferable also from the viewpoint of processing.

JP-A-4-180507 JP-A-5-287347

However, as to the calming of forming in the slag pan, as in Patent Document 1, when carbon powder is sprayed on the slag surface, the carbon powder has a low specific gravity and a small volume, so that it is difficult to enter the slag. For this reason, the effect of carbon powder appears only on the surface side of the slag, and is almost ineffective for slag that forms quickly.
Further, as in Patent Document 2, when carbon powder is blown into the slag, the carbon powder is difficult to disperse throughout the slag because of its low specific gravity and small volume. For this reason, since the effect of carbon powder appears only in the vicinity of the blown position, in order to exert the effect of carbon powder on the entire slag, it is necessary to blow from a large number of positions, workability becomes worse, The equipment configuration is also complicated.

The present invention has been made in view of such circumstances, rapidly sedated with a small amount of molten slag forming, to prevent equipment damage due to overflow of the molten slag, to realize stable maintenance of productive Haikasu It aims at providing the forming sedative material of a pot slag, and its sedation method.

The gist of the present invention made to solve the above problems is as follows.
(1) Molten slag forming soothing material discharged from the converter to the waste pan, 20% to 40% by mass of carbon powder having a particle size of 0.2 mm or more and 2 mm or less, and 35 % by mass or more of moisture A waste pan slag characterized by containing a mixture having a heat decomposable substance that generates gas in the molten slag of 60% by mass or less and a non-permeable flammable substance. Forming sedative material.
(2) The squeezing material for slag pan slag as described in (1), wherein the mass of the mixture stored in the container is 1 kg or more and 10 kg or less.

(3) the (1) and (2) forming sedative material Haikasunabe slag according basicity is characterized by introducing into the molten slag is foamed of 0.8 to 1.5 forming sedation method of Haikasunabe slag.
(4) the forming sedative material of the Haikasunabe slag, the discharge position of the molten slag discharged from the converter, and characterized by introducing between the period until 30 seconds from the discharge start of the molten slag to (3) forming sedative method Haikasunabe slag according.
(5) (1) or (2) a forming sedative material Haikasunabe slag according, after turning on the Haikasunabe, the exhaust Kasunabe, basicity of 0.8 to 1.5 forming sedation method Haikasunabe slag, which comprises introducing the molten slag.

Incidentally, the forming sedative material Haikasunabe slag above (hereinafter, simply referred to as sedation material) charcoal Motoko in the mixture constituting the, defined as follows.

Charcoal Motoko is coke powder, coal powder, such as graphite powder, a substance containing carbon as a main component (more than 80% by weight). The particle size of the carbon powder is defined by the mesh opening of the sieve that can pass. That is, the particle size of 0.2 mm or more and 2 mm or less means particles that can pass through a sieve with a mesh opening of 2 mm and cannot pass through a sieve with a mesh opening of 0.2 mm.

The squeezing material for slag pan slag according to the present invention and the sedation method are such that a mixture containing a predetermined amount of moisture , carbon powder, and pyrolyzable substance is impermeable to flammable molten slag. Since the sedative material stored in a container made of a substance is charged (used), carbon powder can be dispersed in the molten slag by explosive volume expansion energy due to vaporization of moisture. As a result, the formation of molten slag can be effectively suppressed, so a high sedative effect can be obtained even if the total amount of sedative material is small, and the cost of the sedative material is reduced, and equipment damage due to overflow of molten slag This makes it possible to improve workability by preventing the occurrence of the problem and to maintain stable productivity in the refining process.

Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
Here, FIG. 1 is an explanatory view showing the relationship between the diameter of the bubbles in the molten slag and the lifetime of the bubbles, and FIG. 2 is an explanatory view of the forming sedation method of the waste pan slag according to one embodiment of the present invention. is there.

A forming soothing material (hereinafter also simply referred to as a soothing material) for a slag pan slag according to an embodiment of the present invention is a container composed of a mixture containing carbon powder and moisture and made of an impermeable flammable substance. It is what was stored in. This will be described in detail below.

Since carbon powder has poor wettability with molten slag, it has the action of repelling molten slag on its surface, so when this carbon powder enters the slag liquid film between the bubbles, the slag liquid film Eliminated and bubbles coalesce. Here, the relationship between the bubble diameter and the bubble lifetime will be described with reference to FIG.
As is clear from FIG. 1, the lifetime tends to be shortened as the bubble diameter increases, and it tends to burst on the surface of the molten slag, but in particular, the bubble having a diameter exceeding 2 mm (2.0 mm) There was no significant difference in the lifetime, that is, the time until bursting, and it was about 4 seconds.
Therefore, it was found that when bubbles having a diameter of more than 2 mm were combined with carbon powder, it was difficult to obtain a large forming suppression effect because the cost for reducing the lifetime was small. On the other hand, when bubbles having a diameter of less than 2 mm were combined, the knowledge that the forming suppression effect was easily obtained was obtained because of a large reduction in the lifetime.

Moreover, when the present inventors collected each molten slag with a kneading car, a converter, and a waste pan, and investigated the diameter of the bubble which remained in the inside, the knowledge that it was 0.2-5 mm was acquired. It was.
From this, it is presumed that bubbles having a diameter of less than 0.2 mm do not exist, or even if they exist, the number of bubbles is small, so that the influence on forming is small.
Here, for bubbles having a diameter of more than 2 mm, for the reason described above, it is considered that the influence on the forming is small because it bursts easily on the surface of the molten slag without adding a sedative material.

From these findings, if carbon powder can promote the coalescence of bubbles with a diameter of 0.2 mm or more and 2 mm or less and the diameter can be coarsened to more than 2 mm, the life of the bubbles is greatly reduced and the forming is suppressed. It became clear that this would be possible.
However, it is necessary to disperse the carbon powder in the molten slag in order to assure slag forming with a small amount of sedative material. This is because, when the carbon powder is uniformly distributed in the molten slag, the coalescence of bubbles occurs over the entire molten slag, and the forming suppression effect is enhanced.
Therefore, the present inventors considered the use of the volume expansion energy when the gas generating material is gasified as means for dispersing the carbon powder in the molten slag, and conducted the following tests.

First, water, pulp waste, edible oil, and waste plastic, which are inexpensive and readily available, are used as gas generating substances. A mixture of these and various amounts of carbon powder is mixed in a plastic bag and sedated. A material was manufactured, and this sedative material was tested for injection into molten slag that formed during evacuation with an actual machine.
As a result, there were sedatives that exhibited a forming suppression effect and sedatives that did not exhibit a suppression effect when the amount of sedative input was set to a small amount of about 1% by mass of the discharged molten slag amount. From this result, the following thing was discovered about the suitable range of a sedative material.

First, the water content in the mixture is 30% by mass or more and 60% by mass or less.
Here, when the amount of water is less than 30% by mass, the generated gas (water vapor) is insufficient, the volume expansion energy becomes insufficient, and the carbon powder is difficult to disperse inside the molten slag. On the other hand, when the amount of water exceeds 60% by mass, the effect of dispersing the carbon powder is saturated, too much water vapor is generated, and the molten slag is likely to be scattered outside the waste pan, causing damage to equipment. There is a possibility.
From the above, the water content in the mixture was set to 30% by mass or more and 60% by mass or less. Preferably, the lower limit is 35% by mass, further 40% by mass, the upper limit is 55% by mass, and further 50% by mass. To do.

Moreover, the diameter (particle size) of carbon powder is 0.2 mm or more and 2 mm or less.
As described above, the diameter of the bubbles to be coarsened is 0.2 mm or more and 2 mm or less, and in order to enter the slag liquid film between the bubbles and combine the bubbles, The diameter needs to be equal to or less than that of bubbles.
Here, when the particle size of the carbon powder is too large compared to the bubbles, the carbon powder is likely to be sandwiched between the bubbles, so that it is difficult to coalesce. In addition, carbon powder having a large particle size is likely to float on the surface of the molten slag and is difficult to disperse in the molten slag, so that it is difficult to obtain a forming suppression effect.

On the other hand, when the diameter of the carbon powder is too fine with respect to the bubbles, the amount of removing the slag liquid film is small, and it is difficult to promote the coalescence of the bubbles. In addition, since carbon powder with a small particle size has a large surface area, it easily reacts with FeO in the molten slag and generates fine CO bubbles, which facilitates forming. It becomes difficult to be.
For the above reasons, the diameter of the carbon powder is 0.2 mm or more and 2 mm or less, which is the same diameter as the bubbles to be coarsened, but there are some carbon powders of less than 0.2 mm and carbon powders of over 2 mm. (For example, about 20% by mass or less) may be included, and further, if the carbon powder contains not less than 0.2% and not more than 2 mm by 65% by mass or more, the above-described forming suppression effect can be obtained.

The amount of carbon powder having a particle size of 0.2 mm or more and 2 mm or less contained in the mixture is 20% by mass or more and 40% by mass or less.
Here, when the amount of carbon powder having a particle size of 0.2 mm or more and 2 mm or less in the mixture is less than 20% by mass, the proportion of the carbon powder in the mixture is too small, so that the coalescence of bubbles is insufficient and the forming is suppressed. It becomes difficult. On the other hand, when the amount of carbon powder having a particle size of 0.2 mm or more and 2 mm or less exceeds 40% by mass, the remarkable effect of forming suppression is not recognized and the effect is saturated.
From the above, the amount of the carbon powder in the mixture is set to 20% by mass or more and 40% by mass or less. Preferably, the lower limit is 21% by mass, the upper limit is 35% by mass, and further 30% by mass.

The remainder other than moisture and carbon powder in the mixture constituting the sedative material shown above is not particularly specified, but when a pyrolyzable substance is used, the volume expansion energy when generating gas in the molten slag is reduced. It is more preferable because it can be used for dispersion of carbon powder. Examples of the pyrolyzable material herein include pulp waste, waste plastic, edible oil, organic matter such as waste oil, carbonate such as CaCO ₃ , and hydroxylation such as Ca (OH) _2. This applies to things.

As described above, the mixture contains a large amount of moisture, so that the crushing strength is low even when compression-molded, and the mixture is liable to be deformed when subjected to vibration or impact during transportation or the like. Therefore, in order to surely sink into the molten slag, the mixture is stored in a container made of an impermeable flammable substance.
Here, the container is made impermeable so as to prevent the water content from decreasing between the production of the sedative material and its introduction. In addition, the container is made of a flammable substance because it is gasified early in the molten slag and disappears, and the carbon powder contained in the sedative material is easily dispersed quickly into the molten slag, which is more efficient. This is because forming is easily suppressed. As such a container, for example, a slightly hard container such as a plastic bottle is preferable because it has good workability in transportation and charging, but may be a plastic bag.

The mass of the mixture packed in this container is preferably 1 kg or more and 10 kg or less.
If the sedative material is too light, it will be insufficient to sink into the molten slag, making it difficult to obtain a sedative effect. On the other hand, when the sedative material is too heavy, it becomes difficult to handle the sedative material during manufacture or transportation.
Therefore, from the viewpoint of achieving both of these, the mass of the mixture is set to 1 kg or more and 10 kg or less, but the lower limit is preferably 2 kg, more preferably 3 kg, and the upper limit is 8 kg, more preferably 7 kg.

Then , the forming soothing method of the waste pan slag concerning one embodiment of the present invention is explained.
As described above, a molten slag having a lower basicity has a stronger forming property. However, the sedative material of the present invention can obtain a high sedative effect even for such a molten slag.
Hereinafter, the case where it uses for a multifunctional converter method as an example is demonstrated, referring FIG.

In the multi-function converter method, after the hot metal P is dephosphorized in the converter 10, the molten slag S1 in the converter 10 is discharged to a discharge pan 11 installed under the furnace. Here, in order to discharge 10 to 15 tons of molten slag S1 in a short time of about 3 minutes, the basicity of the molten slag S1 in the converter 10 is 0.8 or more and 1. By adjusting to 5 or less (preferably lower limit is 0.9, upper limit is 1.3) and molten slag S1 is formed (foamed), the evacuation property is improved. Here, when the basicity is less than 0.8, since the CaO concentration is low, the dephosphorization ability of the molten slag S1 becomes small. On the other hand, when the basicity exceeds 1.5, the viscosity of the molten slag S1 becomes low. , Forming becomes difficult and excretion decreases.

As described above, the molten slag S2 discharged from the converter 10 and supplied to the slag pan 11 reacts with C in the granular iron contained in the slag and FeO to generate CO bubbles, and rapidly and continuously. Easy to form. The sedative material 12 used for the molten slag S2 needs to have the characteristics of reducing the lifetime of bubbles remaining on the surface of the molten slag S2 and suppressing forming.
The sedative material according to one embodiment of the present invention described above is used for the sedative material 12 having such characteristics. This soothing material enables the carbon powder having the coalescing action and the coarsening action of the bubbles to be uniformly dispersed in the molten slag S2 by the volume expansion energy when moisture is vaporized. It is easy to obtain the effect of carbon powder as a whole. This effect can be obtained even with a high-viscosity low basicity slag in which the lifetime of bubbles tends to be long, and the difference in the effect becomes more remarkable as compared with the prior art.

Therefore, it is preferable to put the sedative material 12 into the slag pan 11 prior to the start of spilling, and the charging position is from the discharge position of the molten slag S1 to the slag pan 11, that is, from the converter 10. It is preferable that the discharged molten slag S <b> 1 has a position where it reaches the inside of the discharge pan 11. Immediately after the start of slagging, the stirring of the molten slag S2 accompanying the discharge is particularly intense in the slagging pan 11, so that the carbon powder can be evenly dispersed in the molten slag S2 by utilizing the stirring energy. Here, the input amount of the sedative material prior to the start of excretion is more preferably 30 kg or more.
Alternatively, the sedative material 12 is concentrated (for example, once, continuously, or divided into multiple times) within 30 seconds from the start of the discharge of the molten slag S1, and the molten slag to the discharge pan 11 is concentrated. It can also be put into the discharge position of S1. The reason is the same as the above-described excretion, and the input amount of the sedative material 12 for 30 seconds from the start of the excretion is more preferably 30 kg or more.

In any of the above-described charging methods, after 30 seconds have elapsed from the start of discharging the molten slag S1, the sedative material 12 may be further charged in accordance with the forming situation. In this case, the sedative material described above can be used in combination with a conventionally known sedative material.
It is preferable that the sedative material is introduced uniformly per unit time for 30 seconds (first half) from the start of evacuation of the molten slag S1 and after 30 seconds have passed since the start of evacuation (second half). At this time, it is preferable that the input amount of the sedative material per unit time in the first half is 2 to 3 times that in the second half.
In addition, the number 13 in FIG. 2 is an operation floor, and the number 14 is a moving trolley.

Next, examples carried out for confirming the effects of the present invention will be described.
The soothing material is made by adding waste plastics (plastic bottles crushed into flakes) and water for water adjustment to pulp waste, coke powder, and graphite powder with a water content of 60% by mass, as necessary. The mixed mixture is added to a plastic bag (volume: 13500 cm ³ , thickness: 0.5 mm), a plastic bottle (volume: 12000 cm ³ , thickness: 1.5 mm), or a paper bag (volume: 13500 cm ³ , thickness: 0. 5 mm) container. Table 1 shows the raw material mixing ratio of the sedative material mixture. The particle size (particle size) of the carbon powder in Table 2 is the particle size of the mixture of coke powder and graphite powder in Table 1, and the particle size is divided into less than 0.2 mm, 0.2-2 mm, and more than 2 mm. It is shown. Furthermore, Table 2 also describes the mass per sedative, but the container is a plastic bag, a plastic bottle, or a paper bag, and its mass is slight relative to the amount of the mixture. The mass of one material is the amount of mixture per sedative material.

Each sedative material (materials A to S) of Examples 1 to 12 and Comparative Examples 1 to 7 shown in Tables 1 and 2 is the result of throwing into the slag pan at the time of sewage in the multifunctional converter method. Table 3 shows. Here, the sedative material is placed in the 4m high waste pan placed below the furnace body before the start of the molten slag waste disposal, and 30 seconds after the start of the waste drainage. Two conditions were investigated when the molten slag was discharged into the slag. When the sedative material is introduced within 30 seconds from the start of slagging, after the dephosphorization process, the converter is tilted while the hot metal is left in the furnace, and the above mentioned slagging ladle is put into the converter furnace port. When discharging the molten slag from, sedative material was introduced through a chute from immediately after the start of evacuation until the end of evacuation. As a result, the molten slag that forms in the waste pan is calmed down. The molten slag was discharged for 3 minutes in all cases. In addition, the mass of the molten slag during sewage was measured with a weigher attached to a moving carriage on which a sewage pan is installed.

In Examples 1 to 12, a mixture in which moisture is 30% by mass or more and 60% by mass or less and carbon powder having a particle diameter of 0.2 to 2 mm is 20% by mass or more and 40% by mass or less is impervious to combustibility. Since sedative materials (materials A to L) housed in a container made of a substance were used, forming was sedated by adding 120 kg of this sedative material, and molten slag could be discharged by 10 tons (target value) or more. In particular, in Example 1, when discharging molten slag having a basicity of 1.1, the sedative material (material A) was placed in a 40 kg decanter before the start of evacuation, and 80 kg after 30 seconds from the start of evacuation. When the molten slab was thrown into the discharge position, the effect of calming was great and 14 tons of molten slag could be discharged. The same result was obtained for Example 2 in which 40 kg of sedative material (material B) was introduced within 30 seconds from the start of the molten slag discharge.

Further, in Example 3, since the ratio of the particle size of less than 0.2 mm was high for the carbon powder used, the effect of promoting the coalescence of bubbles in the molten slag was small and fine compared to Example 2. The formation of CO bubbles made it difficult to obtain a forming suppression effect, and the amount of molten slag discharged was 11.5 tons.
On the other hand, in Example 4, since the ratio of the particle size exceeding 2 mm was high for the carbon powder used, the effect of promoting the coalescence of bubbles in the molten slag was small compared to Example 2, and the molten slag contained It was difficult to disperse and it was difficult to obtain a forming suppression effect, and the discharge amount of molten slag was 11.5 tons.

Moreover, since the sedative material (material E) whose mass of the mixture stuffed in the plastic bag was 0.8 kg (less than 1 kg) was used for Example 5, compared with Example 2, the penetration | invasion to molten slag was not enough. The discharge amount of molten slag was 11 tons.
On the other hand, since the sedative material (material F) in which the mass of the mixture packed in the plastic bottle was 12 kg (over 10 kg) was used in Example 6, the immersion into the molten slag was sufficient. Of molten slag could be discharged. However, since the mass of the sedative material was too heavy, workability such as production and conveyance was worse than that of Example 2.

In Example 7, the sedative material was introduced near the end of the slagging pan. Therefore, compared to Example 2, the sedative material (material G) was less likely to sink into the molten slag, and the discharged amount of molten slag was 10.5. Tons.
In Example 8, the amount of the sedative material (material H) from the start of evacuation to 30 seconds was limited to 24 kg, which is smaller than that in Example 2, so the amount of molten slag discharged was 11 tons. .

In Example 9, since the sedative material (material I) in which the water content in the mixture constituting the sedative material is lower than that of Example 2 was used, the generated water vapor was insufficient and the carbon powder was inside the molten slag. It was difficult to disperse the molten slag, and the amount of molten slag discharged was 10.5 tons.
Furthermore, in Example 10, the amount of water in the mixture constituting the sedative and the amount of carbon powder having a particle size of 0.2 to 2 mm are lower than those of Example 2 (the amount of water is the same as in Example 9). ) Since the sedative material (material J) was used, in addition to the phenomenon of Example 9, it became difficult to suppress forming, and 10 tons of molten slag less than Example 9 could be discharged.

Moreover, Example 11 used the sedative material (material K) whose moisture content in the mixture which comprises a sedative material is lower than the sedative material of Example 2, but carbon powder with a particle size of 0.2-2 mm is used. Since the amount was higher than that of the sedative material of Example 2, the discharged amount of molten slag was 11 tons.
And although Example 12 used the sedative material (material L) whose moisture content in the mixture which comprises a sedative material is higher than the sedative material of Example 2, carbon dioxide with a particle size of 0.2-2 mm is used. Since the amount was lower than that of the sedative material of Example 2, the discharged amount of molten slag was 10.5 tons.
In addition, although Examples 1-12 shown above were the results for the molten slag in which the basicity is in the range of 0.8 or more and 1.5 or less, good results were obtained in all cases.

On the other hand, in Comparative Examples 1 and 2, the amount of water in the mixture constituting the sedative material (materials M and N) was less than 30% by mass and the water content was insufficient, so the carbon powder was not sufficiently dispersed in the molten slag. In all cases, the forming amount could not be suppressed with the same input amount as in Examples 1 to 12, and it was necessary to input about 1.5 times the sedative material.
In particular, for Comparative Example 2, the amount of carbon powder having a particle size of 0.2 to 2 mm in the mixture was larger than that of Examples 1 to 12 (over 40% by mass), but the amount was soothing. It was necessary to add an excessive amount of material.

In Comparative Examples 3 and 4, the amount of carbon powder having a particle size of 0.2 to 2 mm in the mixture constituting the sedative material (materials O and P) was less than 20% by mass, and the amount of carbon powder was insufficient. The coarsening of the bubbles was insufficient, and in all cases, forming could not be suppressed with the same input amount as in Examples 1 to 12, and it was necessary to add about 1.5 times the sedative material.
In particular, in Comparative Example 3, the amount of water in the mixture constituting the sedative material is larger than that of Examples 1-12 (over 60% by mass), but the sedative material is excessively added. There was a need to do.

In Comparative Example 5, since the mixture was used without being packed in a container, the sedative material (material Q) did not sink into the molten slag to be formed, and the sedative effect was small. For this reason, in order to prevent the overflow of the molten slag, it is necessary to suppress the discharge rate of the molten slag, and the discharged amount of the molten slag remains at 7.5 tons (less than 10 tons).
Furthermore, in Comparative Example 6, since the mixture was packed in a water-permeable paper bag, the amount of water was reduced to 24% by mass before the sedative material (material R) was added to the molten slag. For this reason, in order to prevent the overflow of the molten slag, it is necessary to suppress the discharge rate of the molten slag, and the discharged amount of the molten slag remains 9 tons (less than 10 tons).

In Comparative Example 7, the basicity of the molten slag was as low as 0.7 (less than 0.8), so the forming property was quite strong, and the discharge amount of the molten slag remained at 9.5 tons.
From the above, by using the soaking material for slag pan slag and the soothing method of the present invention, the molten slag to be formed is quickly sedated with a small amount of use, and equipment damage due to overflow of molten slag is prevented. As a result, it was confirmed that stable maintenance of productivity could be realized.

As described above, the present invention has been described with reference to the embodiment. However, the present invention is not limited to the configuration described in the above embodiment, and the matters described in the scope of claims. Other embodiments and modifications conceivable within the scope are also included. For example, the case where the forming sedative material and method for squeezing pan slag of the present invention are configured by combining some or all of the above-described embodiments and modifications are also included in the scope of the right of the present invention.

It is explanatory drawing which shows the relationship between the diameter of the bubble in molten slag, and the lifetime of the bubble. It is explanatory drawing of the forming sedation method of the waste pan slag which concerns on one embodiment of this invention.

Explanation of symbols

10: Converter, 11: Waste pan, 12: Sedative material, 13: Operation floor, 14: Moving cart

Claims (5)

A molten slag forming soothing material discharged from a converter to a waste pan, carbon powder having a particle size of 0.2 mm or more and 2 mm or less is 20 mass% or more and 40 mass% or less, and moisture is 35 mass% or more and 60 mass% or less. The slag forming slag is characterized in that a mixture comprising a pyrolyzable substance that generates gas in the molten slag is contained in a container made of an impermeable flammable substance. Wood. In forming sedation material Haikasunabe slag according to claim 1, forming sedative material Haikasunabe slag, characterized in that the mass of said mixture being accommodated in the container is less than 1 kg 10 kg. The forming sedation material Haikasunabe slag according to any one of claims 1 and 2, basicity, characterized in that introduced into the molten slag is foamed of 0.8 to 1.5 forming sedation method of Haikasunabe slag. In forming sedation method Haikasunabe slag according to claim 3, the forming sedative material of the Haikasunabe slag, the discharge position of the molten slag discharged from the converter, 30 seconds from the discharge start of the molten slag Forming sedation method of slag pan slag, which is put in between. The forming sedation material Haikasunabe slag according to any one of claims 1 and 2, after turning on the Haikasunabe, the exhaust Kasunabe, basicity of 0.8 to 1.5 forming sedation method Haikasunabe slag, which comprises introducing the molten slag.

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