KR100558310B1 - An Apparatus and A Method for dry cooling of molten pretreatment slag - Google Patents

Abstract

An apparatus and method are provided for dry cooling a molten waste slag.

The dry treatment apparatus of the molten waste slag, the vessel to separate the molten waste slag and the molten residue to discharge through the discharge nozzle, and is driven to rotate while being cooled directly below the slag discharge nozzle, the molten waste slag dropped therefrom It is configured to include a cooling rotor for primary cooling, and a cooling vessel arranged to cool the wall under the tundish while receiving the cooling rotor, secondary cooling the granular exhaust slag falling after contacting the cooling rotor. Thereby, there is provided a method for dry treatment of the molten waste slag through secondary cooling.

According to the present invention, it is possible to facilitate the use of slag by lowering the content of metal and iron (Metal.Fe) during the treatment slag treatment, in particular, the treatment structure of the molten exhaust slag in the dry form lowers the treatment cost, the molten discharge The working environment of the slag treatment operation is also improved, while the molten exhaust slag is granulated by separating the residual wire in the molten state and dry-cooling the granules, thereby obtaining a further improved effect of facilitating the post treatment operation.

Slag, Exhaust Slag, Molten Exhaust Slag, Slag Treatment Equipment, Dry

Description

An Apparatus and A Method for dry cooling of molten pretreatment slag}             

1 is a block diagram showing a dry treatment apparatus of molten waste slag according to the present invention.

Figure 2 is a detailed view showing the slag discharge nozzle and the cooling rotor and the cooling vessel of the container in the dry treatment apparatus of the molten exhaust slag of the present invention

Explanation of symbols on the main parts of the drawings

1 .... Dry Treatment Equipment of Molten Exhaust Slag

10 .... Container (Tundish) 12 .... Molten Exhaust Slag

12 '.... cooled excreted slag particles 14 .... molten residue

16 .... residual discharge nozzle 18 .... slag discharge nozzle

30 .... cooling rotor 50 .... cooling vessel

52 .... Wall 54 .... Cooling Jacket

The present invention relates to an apparatus and a method for granulating molten excrement slag by dry cooling, and more particularly, to facilitate the use of slag by lowering the content of metal iron (Metal.Fe) during the excrement slag treatment, in particular molten exclusion The slag treatment structure reduces the cost of treatment in the dry form, improves the working environment of the treatment process of the molten waste slag, and granulates the molten waste slag in the molten state by granulation by separating the remnants from the molten state and dry cooling. A dry treatment apparatus and method for molten waste slag which also facilitates.

In general, the molten iron selected through the blast furnace operation in the steel mill contains impurities such as sulfur and phosphorus due to iron ore and coke components, such sulfur and phosphorus components that cause brittleness in the steel produced in molten iron.

Therefore, the molten iron should be removed at the molten iron phase, and the process of treating sulfur and phosphorus is called a molten iron pretreatment.

In other words, the molten iron pretreatment process is a process of removing phosphorus and sulfur from the molten iron by reacting the lime-based dephosphor, the degreasing agent and the molten iron, and when such dephosphorizing agent and the deoiling agent react with the molten iron, slag which is an impurity is produced.

In addition, the slag generated in the molten iron pretreatment process is divided into a powder state and a molten state. The slag in the powder state is removed by a scraper after pretreatment, and the slag in the molten state is tundish (TLC) or ladle ( What is left in the molten state in the processing vessel such as open ladle) is transported to the disposal site for treatment, and the slag at this time is treated as waste slag.

However, when the molten iron is poured into the tundish or ladle after the molten iron pretreatment, the molten iron is not completely separated and remains with the molten waste slag as some remain.

At this time, the melt discharged slag and the melt of the residual remnant is discharged in the distribution hall, the conventional method of discharging used up to now is to lay the cooled discharge slag on the bottom of the distribution site and to pour the melt of the molten discharge slag and the remaining molten iron thereon That's the way.

At this time, in order to suppress the generation of scattering dust, pour the melt in the state of slightly sprayed water on the cooled exhaust slag surface, and when the melt is cooled, mobilize the heavy equipment, take out the coolant, transport it, grind it, and magnetically separate it. Iron and slag with high iron content are separated.

On the other hand, Japanese Laid-Open Patent Publication No. 2003-279270 discloses another conventional slag treatment method technology generated during the molten iron preliminary treatment.

However, when the treatment slag is treated by the other conventional slag treatment method disclosed in the above publication, the treatment cost is increased because several treatment steps are required, and in particular, the molten slag and the residual (remaining) molten iron are simultaneously processed. As a result, the final cooled slag T.Fe (total.Fe) becomes high. Therefore, the use of exclusion slag is limited.

Table 1 below shows the results of analyzing various contents of iron by crushing the excrement slag conventionally treated by another method and separating by particle size.

Analysis of Iron Content in Exhaust Slag Treated by Conventional Methods Classification (by particle size) T.Fe (total.Fe) M.Fe (metal.Fe) FeO Fe ₂ O ₃ Sujae City 41.13 20.07 17.74 10.39 1-2.36mm 81.11 78.62 3.19 tr 500㎛-1mm 72.28 59.25 10.08 7.42 150-500㎛ 56.90 43.62 13.59 3.88 45-150㎛ 47.13 27.61 15.94 10.19 45 ㎛ or less 35.70 13.39 18.29 10.71

That is, as can be seen in Table 1, the conventional excrement slag treatment method is a very high content of T.Fe by particle size, in particular, it can be seen that the large content% corresponds to almost M.Fe.

Therefore, in the conventional method of treating waste slag, since the waste slag contains excessive M.Fe, its use is limited. For example, when treating slag, expenses such as crushing cost and charity separation cost are required. There are several problems, such as the need for additional post-treatment, which is inefficient, and requires a separate treatment of high pH wastewater generated from sprinkled water, especially for shatterproof dust.

The present invention has been made in order to solve the above-mentioned conventional problems, the object of the present invention is to remove the residual molten iron first, and then to granulate while cooling the exhaust slag in the molten state in the dry form, the conventional waste slag treatment process The present invention provides a method and method for dry treating slag of molten ash slag that facilitates the use of slag by reducing the content of M.Fe per particle generated in the present invention, reducing the processing cost, and facilitating post-treatment of granulated slag. It's there.

As a technical aspect for achieving the above object, the present invention, a container having a residual and slag discharge nozzle for separating the charged molten waste slag and the molten residual, and separately discharged;

A cooling rotating body arranged to rotate while being cooled directly under the slag discharge nozzle of the container, and primarily cooling the molten exhaust slag falling from the slag discharge nozzle; And

A cooling vessel arranged to cool the wall while the cooling rotor is accommodated therein, and to cool the secondary exhaust slag that falls after contacting the cooling rotor through wall contact;

Characterized in that configured to include.

In another aspect, the present invention, the step of charging the molten waste slag and the molten residue after melting the waste slag in the tundish to separate through the dam;

A first treatment step of drop-impacting the molten waste slag separated from the molten residue in the tundish by a slag discharge nozzle of the tundish to the cooling rotary body below the tundish so as to first cool granulate the molten waste slag; And,

A second processing step in which the primary cooling granulated exhaust slag is secondary cooling granulated while making secondary contact with the cooling wall of the cooling vessel by the rotational force of the cooling rotor;

Characterized in that configured to include.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram showing a dry treatment apparatus of the molten waste slag according to the present invention, Figure 2 is a detail showing the slag discharge nozzle and the cooling rotor and the cooling vessel of the container in the dry treatment apparatus of the molten waste slag of the present invention It is also.

As shown in FIG. 1, the dry treatment apparatus 1 of the molten exhaust slag according to the present invention may be largely divided into a container 10, a cooling rotating body 30, and a cooling container 50. The elements 10, 30 and 50 are described in detail as follows.

First, as shown in FIG. 1, the container 10 separates the charged molten waste slag 12 and the molten residue 14 and separates and discharges each of them. 18).

By the way, the container 10 of the present invention can actually use a tundish having a dam 20 for separating the molten waste slag 12 and the molten residue 14, but this is only one embodiment. However, the present invention is not limited thereto.

In addition, although the discharge nozzles 16 and 18 are schematically illustrated in the drawings, the discharge nozzles 16 and 18 are provided with opening and closing plates for controlling the discharge of the molten remnant 14 and the molten exhaust slag 12.

On the other hand, the charging nozzle 22 for charging the molten waste slag 12 including the molten residue into the tundish 10 is arranged on the dam 20 side, and eventually the specific gravity is heavy inside the dam 20. When the molten residue 14 sinks and the slag with low specific gravity floats and the water level is higher than the dam 20, only the molten exhaust slag 12 on the water level overflows and moves toward the tundish slag discharge nozzle 18 to melt. Only the exhaust slag 12 is to be discharged.

At this time, it is important that the molten waste slag 12 charged into the container 10 is formed at a temperature of 30-40 ° C. higher than the melting point of the waste slag to facilitate granulation thereof, and the reason thereof will be described in detail later. .

That is, in the molten waste slag dry treatment apparatus 1 of the present invention, since cooling through the conventional spraying water causes environmental pollution, there is a constitutive feature in the dry treatment, which is the secondary molten waste slag 12. ) Through granulation through cooling.

Then, when the molten exhaust slag 12 freely falls through the nozzle 18 and forms a stream and contacts the cooling rotor 30, as shown in FIG. The slag 12 is granulated. If the temperature of the molten waste slag 12 is too high than the melting point of the waste slag, the cooled slag grains may adhere to each other, so that the temperature of the molten waste slag 12 is constant. It must be adjusted.

For example, since melting | fusing point of waste slag is 1350 degreeC normally, it is preferable to maintain the temperature of the said molten waste slag at the temperature of 1380-1390 degreeC.

2 shows the slag discharge nozzle 18 of the tundish 10 which is the container in detail, wherein the discharge diameter D of the slag discharge nozzle 16 is 5-7 mm. desirable.

That is, if the temperature of the molten waste slag 12 through the nozzle 18 is 1380 ° C, as described above, even if the temperature of the nozzle 18 is maintained at a high temperature, the maximum temperature is 700 ° C or less. While passing through the discharge diameter (D) portion is instantaneously cooled by the temperature difference gradually reduces the discharge diameter of the nozzle, and thus it is preferable to maintain the discharge diameter of the slag discharge nozzle 18 to 5-7mm, at this time If the discharge diameter is larger than 7mm, as shown in Figure 2, when the molten waste slag 12 falls free from the nozzle, the stream of the molten waste slag becomes too thick, making it difficult to form the particle size during cooling of the molten waste slag 12 To cause.

Next, FIGS. 1 and 2 show the cooling rotary body 30 of the apparatus 1 of the present invention. The cooling rotary body 30 of the present invention is a slag discharge nozzle of the container 10. It is arranged so as to be driven in rotation while being cooled directly under 18), and configured to primaryly cool the molten exhaust slag 12 falling from the slag discharge nozzle 18.

1 and 2, the cooling rotor 30 is rotationally driven as a motor 34 on the support 32 provided in the center of the cooling vessel 50, the supply coolant in the interior Consists of an umbrella-shaped rotating body having a cooling water passage 36 to be circulated, and the cooling water passage 36 through which cooling water is circulated is formed in the cooling rotating body 30.

In addition, the cooling water pipe 38 is connected to the central portion of the cooling rotor 30 through a rotary joint 38a, and the like, while the cooling water is circulated, the umbrella-shaped cooling rotor 30 is cooled while driving a motor. The molten exhaust slag 12 which drops and contacts while rotating in time is granulated with primary cooling.

At this time, the rotational speed of the cooling rotor 30 is preferably adjusted to 5-10rpm, the reason for this will be described in detail later, but if the speed of the cooling rotor 30 is too low melt slag slag The cooling rotor 30 of 12 is densely contacted to lower the cooling effect and, conversely, to generate high and unnecessary power costs.

Next, FIG. 1 and FIG. 2 shows the cooling vessel 50 of the apparatus 1 of the present invention, the cooling vessel 50 of the present invention, while the cooling rotor 30 is accommodated therein The wall 52 is arranged to be cooled under the tundish, and is configured to secondaryly cool the granular exhaust slag 12 'that falls after contacting the cooling rotor 30 through wall contact.

At this time, as shown in Figure 2, the wall 52 of the cooling vessel 50 is built in the cooling jacket flowing the cooling water 54 is configured to be recycled as steam by the cooling water of the cooling jacket 54 is hot.

That is, when the slag 12 ′ granulated in the high temperature state contacts the wall 52 of the cooling vessel 50 while continuously falling from the cooling rotor 30, the slag is more completely cooled and additionally. When granulated, the temperature of the slag is transmitted to the jacket 54 of the wall 52 while the heated temperature in the jacket is recycled to the steam source while being purified, thereby providing advantages in terms of equipment operation.

In addition, the lower part of the cooling container 50 is opened, through which the collection tank 70 collecting the exhaust slag 12 ′ granulated in the dry state by the first and second cooling is disposed.

Next, look at the dry treatment method of the molten waste slag through the apparatus (1) of the present invention as follows.

As shown in Fig. 1 and Fig. 2, in the dry treatment method of the molten waste slag of the present invention, the molten waste slag 12 and the molten residuum 14 in which the waste slag is molten are charged into the tundish 10 to be damned. Separating through the (20), and the molten exhaust slag (12) separated from the molten residue 14 in the tundish 10 through the slag discharge nozzle 18 of the tundish cooling tumbler A first processing step of drop-impacting the molten exhaust slag 12 to form primary cooling granules; and the primary cooling granulated exhaust slag 12 'is rotated by the cooling rotor 50 by the rotational force of the cooling rotor. It is made of a second processing step of granulating the secondary cooling while the secondary contact with the cooling wall 52 of the.

That is, when the melt mixed with the molten exhaust slag 12 and the molten residue 14 is charged into the tundish 10, which is a container in which the dam 20 is installed, the molten waste slag is caused by the specific gravity difference inside the dam 20. (12) and the molten residue 14 are separated by the overflow action.

At this time, the separated molten residue 14 inside the dam 20 is discharged through the nozzle 16 attached to the lower portion of the tundish 10 and cooled in the cold wire 16a and reused as steelmaking scrap. Since the scrap of residual wire does not matter in shape, it is good to discharge it to the cold wire 16a side through the nozzle 16. As shown in FIG.

Next, the molten exhaust slag 12 freely falls on the cooling rotor 30 through the other nozzle 18 of the tundish 10.

At this time, as shown in Figure 2, the molten exhaust slag 12 should be dropped into the liquid phase, if the temperature is too high granulated slag particles granulated by the cooling contact with the cooling rotary body 30 is rotationally driven Can be attached.

Therefore, it is preferable that the temperature of the molten waste slag 12 is not too high than the melting point of the waste slag. Preferably, the melting slag 12 is about 30 to 40 ° C higher than the melting point of the waste slag.

However, when the distance between the nozzle 18 and the cooling rotating body 30 is far, the molten exhaust slag 12 is cooled during the fall, so that the slag particles are less likely to adhere to each other. If the temperature is high, the interval between the nozzle and the cooling rotating body may be increased. In this case, since the equipment space is increased, it is more preferable to adjust the temperature.

Meanwhile, the molten exhaust slag freely falling through the slag discharge nozzle 18 of the tundish 10 is preferably maintained at a constant stream. For this purpose, the discharge diameter of the nozzle 18 is adjusted. desirable.

That is, in order to adjust the thickness of the stream during free fall of the constant molten exhaust slag 12, as shown in Figure 2, the discharge diameter (D) of the nozzle 18 is most preferably 5-7mm.

When the nozzle discharge inner diameter is smaller than 5 mm, the molten slag is difficult to flow out, and when the nozzle discharge inner diameter is smaller than 7 mm, particles of granulated slag become larger, which causes a problem of lowering the cooling rate of the slag particles.

At this time, even if the nozzle discharge diameter (D) is larger than 7 mm, if the distance between the nozzle and the cooling rotor becomes far, the thickness of the stream becomes thinner due to the surface tension of the molten slag during the fall, so that some extent is compensated. Since it is increased, it would be most desirable to use a nozzle having a discharge diameter of 5-7 mm.

Next, the molten waste slag 12 freely falling from the nozzle 18 of the tundish 10 collides with the rotating cooling rotor 30, which is preferably an umbrella type as shown in FIG. 1. The cooling rotor 30 is cooled by cooling water circulated therein.

At this time, the rotational speed of the cooling rotor 30 also affects the granulation 12 ′ of the molten exhaust slag 12, but if there is no rotation, the melting continues to be melted at the same point on the surface of the cooling rotor 30. There is a problem of the drop slag falling contact.

However, the rotation of the cooling rotor 30 is preferably rotated as low as possible, and on the contrary, it is not necessary to rotate the cooling rotor 30 more than necessary.

That is, the high speed rotation of the cooling rotor 30 causes energy loss such as unnecessary power ratio, and at this time, the preferred rotation speed of the cooling rotor 30 is 5-10 rpm.

At this time, when the rotational speed of the cooling rotor 30 is 5rpm or more, there is no fear that the molten exhaust slag 12 falls on the cooling rotor 30 at the same position. It is uneconomical.

Next, the molten exhaust slag 12 which falls freely and collides with the cooling rotor 30 is granulated to be quenched and released into the granular state, and the particles are in the centrifugal force direction of the cooling rotor 30 and the gravity of the particles. Force in the falling direction is scattered in the synthesized trajectory direction,

As such, the scattered slag particles collide with the wall of the cooling container 50, that is, the cooling jacket 54, and then collide again with the cooled container wall 52.

Therefore, when slag particles collide with the wall 52 of the cooling vessel 50, the slag particles fall down again, are collected in the collection tank 70, and the granulated slag particles are processed in a form that is easily processed for post treatment. do.

In particular, it is possible to reduce the overall operation cost by eliminating the need for sprinkling during slag cooling, thereby eliminating the need for additional work such as wastewater treatment.

On the other hand, when granulating the molten slag, it is preferable to control the amount of cooling water and the molten slag outflow so that the surface temperature of the cooling rotor 30 and the cooling vessel 50 is between 20 to 50 ° C.

That is, the lower the temperature of the cooling rotor 30 and the cooling vessel 50, the better, but if the surface temperature is lower than 20 ℃, a separate cooling equipment for lowering the temperature of the cooling water is required specially, economical low, on the contrary If the surface temperature is higher than 50 ℃, the cooling capacity is lowered, in particular, the thermal stress is generated in the device, the life is also reduced, so that the temperature of the cooling rotor 30 and the cooling vessel 50 to be 50 ℃ or less is supplied to the It is desirable to adjust by adjusting the temperature of the cooling water.

As described above, according to the dry treatment apparatus and method of the molten waste slag of the present invention, after the residual molten iron is first removed, the molten waste slag is granulated while cooling the molten waste slag in a dry form, thereby generating particles generated in the conventional waste slag treatment process. By reducing the content of M.Fe per unit, the slag can be recycled smoothly, and its specific gravity is high, so it can be used as an aggregate for civil engineering.

In addition, since the molten exhaust slag is cooled in a dry form, water use and generated wastewater treatment are not required as compared to the conventional spraying method, and thus, it is possible to reduce the operating cost of the equipment while simplifying the installation as a whole. It provides an excellent effect such that the content of water is small, so that the dust collecting process is also easy.

While the invention has been shown and described in connection with specific embodiments so far, it will be appreciated that the invention can be varied and modified without departing from the spirit or scope of the invention as set forth in the claims below. It will be appreciated that those skilled in the art can easily know.

Claims (7)

A container (10) having a residual molten slag (12) and a molten residue (14) separated from the charged molten waste slag (12), each of which is separated and discharged from each other; Cooling rotating body which is disposed so as to rotate while being cooled directly below the slag discharge nozzle 18 of the vessel 10, and primary cooling the molten exhaust slag 12 falling from the slag discharge nozzle 18 ( 30); And While the cooling rotor 30 is accommodated therein, the wall 52 is arranged to be cooled under the tundish, and the wall slag 12 ′ that falls after contacting the cooling rotor 30 is contacted with the wall. Cooling vessel 50 for secondary cooling through; Dry treatment apparatus of the molten waste slag, characterized in that configured to include 2. The container 10 according to claim 1, wherein the vessel 10 is composed of a tundish having a dam 20 separating the molten exhaust slag 12 and the molten remnant 14, The cooling rotor 30 is rotationally driven as a motor 34 on a support 32 provided at the center of the cooling vessel 50, and an umbrella-shaped circuit having a cooling water passage 36 through which the supplied cooling water is circulated. Consists entirely The wall 52 of the cooling container 50 has a cooling jacket 54 in which cooling water flows, so that the cooling water of the cooling jacket 54 is heated to be recycled as steam. The molten waste slag 12 charged into the container 10 is formed at a temperature of 30-40 ° C. higher than the melting point of the waste slag to facilitate granulation thereof. Surface treatment temperature of the cooling rotary body 30 and the cooling vessel 50 is 20-50 ℃, characterized in that the dry treatment apparatus of the molten exhaust slag According to claim 1, wherein the discharge diameter (D) of the slag discharge nozzle 16 of the container 10 is formed of 5-7 mm, Drying apparatus of the molten ash slag, characterized in that the rotational speed of the cooling rotor 30 is composed of 5-10 rpm. Charging the molten waste slag 12 and the molten residue 14 into which the waste slag is melted in the tundish 10 and separating the molten waste slag through the dam 20; The molten waste slag 12 which is separated from the molten residue 14 in the tundish 10 is dropped and collided with the cooling rotor 30 below the tundish through the slag discharge nozzle 18 of the tundish. A first processing step of primary cooling granulation 12; And, A second processing step in which the primary cooling granulated exhaust slag 12 ′ is secondary cooled and granulated while making secondary contact with the cooling wall 52 of the cooling vessel 50 by the rotational force of the cooling rotating body; Dry treatment method of the molten waste slag, characterized in that configured to include The molten waste slag 12 is charged into the tundish 10 at a temperature of 30-40 ° C. higher than the melting point of the waste slag to facilitate granulation thereof. The surface temperature of the cooling rotating body 30 and the cooling vessel 50 is maintained at 20-50 ℃ dry treatment method of the molten exhaust slag The discharge diameter (D) of the slag discharge nozzle 16 of the container 10 is formed in 5-7 mm, Drying method of the molten ash slag, characterized in that the rotational speed of the cooling rotor 30 is made of 5-10 rpm.

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