JPS60137856A - Molten slag treatment and apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Technical Field of the Invention J] The present invention relates to a method and apparatus for treating molten slag discharged from blast furnaces, converters, etc. The molten slag is cooled using an endothermic gasification reaction, which not only improves the cooling efficiency and eliminates the need for other refrigerants, but also effectively recovers the heat retained in the slag. This invention relates to a molten slag processing method and apparatus capable of generating useful gas.

Technical background of the invention and its problems 1 Generally, molten slag discharged from blast furnaces, converter furnaces, electric furnaces, etc. is processed by dry pit method, water pulverization method, wind pulverization method, etc. in order to use it as aggregate, which is a building material. The falling oil droplet granulation method is explained based on FIG. The molten slag 2 is dropped onto a disk-shaped rotary granule 4 rotating horizontally in a granulation tank 3, and is scattered and granulated by the energy of the collision. The slag droplets fall and are assimilated by the cold lJI air rising from below, and the refrigerant 5 placed at the landing point prevents the granulated slag 6 from re-fusing. It looks like this.

Note that 42 is the rotation axis of the rotary granule 4.

However, this type of conventional method has the following problems.

■ Since air is used as the cold N gas, the cooling effect is small, and it is necessary to prevent the re-fusion of the granulated slag (particle size 3 to 20 mm), so a large amount (approximately twice as much as the granulated slag) of cold l55 is used. (Slag slag powder with a particle size of 2 mm or less) is considered to be core material.

■ Since the refrigerant 5 is used in circulation, it is necessary to classify the granulated slag 6 and the refrigerant 5, so the air diffuser plate 41/!
The refrigerant and granulated slag are air-classified in the classification section 40 while being fluidized by the cooling air 7 introduced through the refrigerant.
A large amount of refrigerant is cut out from the rotary valve 8 together with the granulated slag, so after being cut out, the refrigerant is separated by another mechanical classifier (not shown), and then re-introduced into the granulation tank 3 through the refrigerant input port 9. I'm returning it. Therefore, not only is expensive equipment required for classifying and transporting the refrigerant, but the running costs are also inevitably increasing.

■ Well, a large amount of air is required to cool and fluidize the granulated slag, and this equipment is not suitable. and running costs will also be very large.

■ The temperature of the refrigerant and granulated slag in a high temperature state decreases during mechanical classification, resulting in a corresponding loss of recovered heat.
Furthermore, since the particle size of the refrigerant is small, it is difficult to recover heat, so that the heat retained in the refrigerant cannot be recovered at all.

■ Another granulation method is known as the wind crushing method, but since this involves 'C granulation' using a jet of cooling gas, one gas is required to cool a large amount, and the equipment is expensive. There were problems in that not only the size increased, but also the running cost increased by +i'4 It, and slag wool was generated.

The present invention has been devised to effectively solve the following problems.

[Objective of the Invention J The object of the present invention is to improve the cooling efficiency of slag by using a gas containing high carbon content as a cooling gas, thereby not only eliminating the need for other refrigerants but also reducing the heat retained in the slag. An object of the present invention is to provide a method and apparatus for processing molten slag, which can effectively recover molten slag, generate useful gas, and further reduce equipment costs and running costs significantly.

[Summary of the Invention 1] The method of the present invention, when granulating molten slag, blows cold N1 gas containing high carbon content such as pulverized coal into molten slag droplets granulated by collision with a rotating granule. (=The above objective is achieved by performing cooling while performing an endothermic gasification reaction.

In addition, the present invention provides a rotary granule that prevents the molten slag from colliding with the surface, scattering, and covering the granules. By providing a cooling means for cooling and assimilating the endothermic gasification reaction while blowing it, the objective described in J.2 is achieved.

Embodiments of the Invention A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

First, FIG. 2 is a schematic vertical sectional view showing a processing apparatus according to the present invention.

As shown in the figure, numeral 10 is a granulation tank whose lower end is reduced to an inverted conical shape and is in a closed state. A thick disk-shaped rotary granule 11 is located approximately in the center of the granulation tank 10 with a drive shaft 26.
, a bearing 27, and a gear 28 so as to be horizontally rotatable, and the molten slag falling onto the top surface is scattered by the energy of the collision and granulated. The gear 28 is connected to a drive source (not shown), and the drive shaft 26
A double pipe 30 is connected to the end of the pipe via a rotary joint 19. The drive chamber 25 is open to the atmosphere and is sealed with the granulation tank 10 by a bearing 27. This disc-shaped rotary granule 11 is made of a porous heat-resistant material such as ceramics or sintered alloy. The interior is cooled by circulating a coolant (water, etc.) from the vibrator 30.

A dish-shaped turn dish 14 is provided at the top of the granulation tank 10 to receive molten slag '13 discharged from a blast furnace (not shown) and flowing down in the gutter 12. A nozzle 1 is inserted into the upper surface of the rotary granulation body 11 by penetrating the upper wall of the granulation tank '10 at approximately the center of the bottom.
5 (=JG) is installed so that the molten slag can fall in the direction toward the rotary granule 1. The centers of rotation of the nozzle 15 and the rotary granule 11 are shifted from each other to change the point of impact of the molten slag on the granule. A rod-shaped slot (・flange 1) for opening the nozzle 15.
6 is installed to be able to move up and down in the vertical direction, and controls the fall of the molten slag 13.

A cooling means 17, which is a feature of the present invention, is provided between the tip of the nozzle 15 and the rotary granule 11 for cooling and solidifying the molten slag droplets being granulated and scattered.

Specifically, this cooling means 17 is the rotary granule 1 described in 2.
It mainly consists of a ring-shaped header 18 provided on one side of the granulation tank 1, and a cooling gas pipe 19 connected to the ring-shaped header 18 and used to supply cooling gas from the outside of the granulation tank 10 to the header 18. . A large number of injection nozzles 20 are formed in the header 18 and are arranged to face the upper surface of the rotary granule 11, and are configured to inject cold FI 11 gas. Furthermore, the quantity of header 18 is 1! It is not limited to ii, but may be a plurality of concentric stages (), and its shape is not limited to a ring shape.

The cooling gas is made by mixing CO2 gas, water vapor, or a gas containing both CO2 gas and water vapor with fine powder of pulverized coal, coke, or charcoal, and blows this onto the flying molten slag droplets. The endothermic gasification reaction
C It is designed to be cooled. The fine powder used is 200 mesh, which is about 80% of the size of a melon, so that the gasification reaction can be easily carried out.

-h, The upper wall 21 of the granulation tank 10 is used to remove reducing gases such as CO and H2 from outside the tank during the endothermic gasification reaction.
y: A high-temperature gas take-off 1" 22 for cutting the slag is installed, and a coterie valve 23 is installed at the lower end of the granulation tank 10 for cutting out 14-grain slag and discharging it to the outside of the tank.
is installed.

Next, the method of the present invention will be explained based on the processing apparatus configured as described above.

First, approximately 1
The molten slag 13 at 350°C is once transferred to the turn dish 14.
After that, it falls onto the upper surface of the rotating granule 11 rotating from the nozzle 15, and mainly collides with it.] - It is granulated into droplets due to energy and flies fit <'? I.

First, a cooling gas Q containing carbon-containing powder is injected onto the upper surface of the rotary granule 11 from the injection nozzles 20 of the header 18 constituting the cooling means 17.
The water vapor, CO2, and powder in the ll gas are instantaneously heated by contact with the high dd molten slag, causing an endothermic gasification reaction as shown in the above equation.

C+1-12 0-sCO+ 8 2 -31.4 k
cal/molC+COz-)2GO-38,2kc
al/mol Since this reaction is a large endothermic reaction, the slag droplets are rapidly cooled and roll toward the outer periphery on the upper surface of the rotary granule 11 and are scattered, and after N, the slag droplets are rapidly cooled and scattered.
As particles that leave 1 -C and solidify at the bottom of the tank, j
(1: fi.

During this granulation, the cooling water in the C1 rotary granule 11 passes through the porous minute holes and easily seeps out onto the surface.
This acts as a lubricant (prevents seizure of the surface I\, smooth granulation, and cools the slag droplets.
is promoted.

The humidity of the granulated slag is approximately 700°C until it is deposited in the granulated slag, and the granulated slag no longer re-fuses with itself, so a special refrigerant is filled in the inner chamber of the tank. There is no need to keep it.

Then, the granulated slag 2/I deposited at the bottom of the tank is sequentially cut out by the rotary valve 23, and then the heat exchange tower (
The waste is transported to (not shown) for heat recovery, and is then crushed by a crusher and used as sand.

On the other hand, the high temperature (
The reducing gas (Co, H2) at a temperature of about 100°C is placed on the upper wall of the tank.
The high-temperature gas is taken out from the hot gas outlet 22 provided in 1, and excess unreacted pulverized coal and ash are removed in a dry dust remover (not shown), and then used as a fuel or reducing agent: High F
It will be transferred to etc.

In addition, the generated high-temperature gas can be used not only as fuel or reducing gas, but also as a raw material gas for chemical industrial synthesis such as ammonia synthesis and methanol synthesis.

Incidentally, when the high-temperature gas is used in a furnace such as a blast furnace, a direct reduction furnace, or a smelting reduction furnace, in which pulverized coal injection is already adopted, it is not necessary to pass it through a dust remover. Thus, when cooling molten slag, the present invention utilizes endothermic heat absorption when carbon undergoes a gasification reaction with water vapor or GO2 gas by blowing a cooling gas containing lO1 carbon-containing material. By cooling the granulated droplets with air, a large cooling effect can be achieved, unlike conventional air cooling.

Therefore, the granulated slag can be sufficiently cooled with only the cooling gas.
Since re-fusion of the granulated slag is eliminated, the refrigerant conventionally filled at the bottom of the granulation tank is not required, and the amount of cooling gas can be reduced.

Therefore, the running cost of the equipment can be significantly reduced.

In addition, since no refrigerant is required as shown above, the classifier that was previously required to separate the refrigerant and slag particles is no longer required, which not only contributes to reducing equipment costs, but also reduces the need for classification (some Also, heat loss due to the refrigerant is eliminated, and the recovery efficiency of heat retained in the slag can be improved.

Furthermore, the waste heat of molten FA11 slag is used to convert high carbon content such as C coal, charcoal, and coke into useful gas. It can also be used as a direct reduction agent, a river reducing agent, or a synthetic raw material gas for the chemical industry.

Also, this produced gas is already at a high temperature! There is no need to preheat when using -F.

Furthermore, compared to conventional wind crushing, the granulation of the present invention is carried out by one energy of impinging the molten slag on the rotary granule, so cooling gasification can be significantly reduced.

In addition, since the cooling gas only cools the granulated droplets and does not crush them, it also prevents the generation of glass wool.
However, it is also possible to achieve compactness of the device itself.

Incidentally, C in the above embodiment used a disc-shaped rotating granule, but the granulation is not limited to this because the energy of collision is mainly C, and as shown in FIG. It is also possible to use a drum-shaped rotating granule 50. In addition, the granule is rotated until the collision point of the molten slag of the granule L is changed so that the molten slag that is It is a good idea to prevent burning of the granules into the granules.Therefore, if a disk is used, As shown in Figure 2, the center of the nozzle 15 and the center of rotation of the granules are offset.A modification of this example is to use separate supply devices for the C1 cooling gas and the high carbon content, respectively. The granules are supplied into the granulation chamber 41, and the two are mixed together.

1. Effects of the Invention J In summary, the present invention exhibits the following excellent effects.

(1) Since the large endothermic reaction when carbon gasifies is used to cool the C granulated oil droplets, the cooling effect can be greatly increased.

[2] Therefore, the granulated slag can be sufficiently cooled and the refrigerant that is conventionally required can be made unnecessary, reducing running costs and reducing installation costs due to no use of a separating machine.

(3) Heat loss due to refrigerant and classifier is eliminated, and it is possible to improve the recovery efficiency of heat retained in the slag.

fil) Cco using 1 da 6 heat of melted h1 varnish slag,
It is possible to obtain useful reducing gases such as +-+ lily.

(!J+ 4J's construction is simple, so it can be easily adopted into existing equipment.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 shows a conventional processing device, and Fig. 2 shows a schematic vertical sectional view of the processing device according to the present invention, and Fig. 3 shows a modified example. There is a schematic vertical IJJt view showing the figure. In addition, in the figure, 10 is a granulation In, 11, 50 is a rotary granule, 13 is a molten slag, 17 is a cooling means, 18 is a header, 19 is a cooling gas introduction pipe, 24 is a granulated slag, 9
is a cooling gas. Patent Applicant: Ishikawajima Ban￥A Juukonigyo Co., Ltd. Representative Patent Attorney: Makoto Kinutani 111 1st error

Claims (2)

[Claims] (1) Molten slag is granulated by colliding with a rotating solid body,
A method for treating molten slag, characterized in that granulated slab droplets are brought into contact with a cooling gas containing a high carbon content such as pulverized coal to cause an endothermic gasification reaction and cool N1. (2) A rotary granule for colliding molten slag with the surface and scattering it to form granules, etc., and contacting the scattered slag droplets with a cooling gas containing high carbon content such as pulverized coal. A processing apparatus for molten slag, characterized in that it is equipped with a cooling means for solidifying the molten slag while undergoing an endothermic gasification reaction at a temperature of 8μ.