JP3110270B2 - Method and apparatus for dissolving component adjusting material in molten slag for rock wool - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention adjusts a slag component and temperature by heating a molten slag of a main raw material stored in an electric furnace with electric power from an electrode while charging a component adjusting material to the molten slag. The present invention relates to a method and an apparatus for dissolving a component adjusting material in a molten slag for rock wool.

[0002]

2. Description of the Related Art When producing hot metal in a blast furnace, a large amount of molten slag is discharged into a large site to form a solidified slag block, which is then crushed into slag crushed stone, aggregate and roadbed material. Or it was used for landfills. After that, the molten slag by-produced in the blast furnace was quenched with water to form granulated slag, which was used for blast furnace cement, cement mixture, concrete aggregate, etc.
It has come to be used as a raw material for rock wool used as a heat insulator.

That is, a molten slag by-produced from a blast furnace is charged into an electric furnace, and a component adjusting material is charged into the molten slag while heating the molten slag of the main raw material stored in the furnace by electric power from electrodes. The production of molten slag for rock wool is performed by adjusting the slag component and temperature. In this method, a high-temperature molten slag is heated in an electric furnace, so that a small amount of energy is required to dissolve the component adjusting material to be charged into the molten slag, thereby saving energy. Generally, molten slag is charged in batches from a slag charging inlet provided in an electric furnace, and a predetermined amount of a component adjusting material is charged from another component adjusting material charging inlet, and heated to a predetermined temperature by an electrode. I have.

As a means for shortening the time for dissolving the component adjusting material in the molten slag stored in the electric furnace, it is well known that an inert gas is blown into the molten slag and the molten slag is stirred by gas bubbling. is there. For example, Japanese Unexamined Patent Publication No. 63-69731 discloses that a carbonaceous lance is inserted into an electric furnace through a support member, pulled out, and vertically movably mounted to dissolve a component adjusting material, and inert gas is passed through the carbonaceous lance. Is blown into molten slag in an electric furnace.

In Japanese Patent Application Laid-Open No. 63-89439, a component adjusting material is usually charged from above onto the surface of molten slag.
Even in the case of powdery component adjusting materials, the component adjusting materials often do not dissolve uniformly even when the inert gas is blown into the molten slag from the gas bubbling lance and agitated. An injection of a component adjusting material together with an active gas into a molten slag is disclosed.

[0006] Further, Japanese Patent Application Laid-Open No. 1-111749 discloses FIG.
As shown in FIG. 7, a plurality (two in the drawing) of component adjusting material inlets 4A are provided in a furnace lid 7A placed over an electric furnace 8E, and each component adjusting material dispensing and feeding device 2A is connected to each component adjusting material inlet 4A. I do. Further, in order to stir the molten slag, the two gas bubbling lances 1A are fixed to the furnace lid 7A and installed. In the electric furnace 8E, a molten slag 9A of a main raw material is mainly charged in batches and stored in a predetermined amount. The component adjusting material is supplied little by little from the dispensing and feeding device 2A via each component adjusting material loading port 4A. At the same time, bubbling is performed by blowing an inert gas from two gas bubbling lances 1A. By this gas bubbling, the molten slag and the component adjusting material are stirred and mixed to shorten the melting time of the component adjusting material.

[0007]

As described in the above prior art, gas bubbling is generally used as a stirring means for accelerating dissolution of a component adjusting material in a molten slag for rock wool. Actually, the insertion position and the insertion angle are not always clearly defined.

According to the present inventors' investigation on the insertion position and the insertion angle of the gas bubbling lance, when the insertion position of the tip of the gas bubbling lance is improperly close to the furnace wall of the electric furnace, the vicinity of the furnace wall is removed. The flow velocity of the flowing molten slag increases, and the damage to the furnace wall refractories is hastened. Further, there is a problem that the molten slag in the furnace is locally stirred and is hardly stirred in the entire furnace. Further, as shown in FIG. 7, when the gas bubbling lance 1A is inserted into the molten slag with an inclination, there is a problem that the gas babbling lance is easily broken due to the vibration of the gas bubbling lance due to the bus bubbling.

On the other hand, when shortening the melting time of the component adjusting material by gas bubbling as in the prior art described above, the surface temperature of the molten slag is high when the component adjusting material is melted in the electric furnace, so The amount of heat dissipated increased, and a large amount of power had to be supplied to keep the temperature of the molten slag constant. Conventionally, as described above, one electric furnace is used as a means for supplying a blast furnace slag to an electric furnace and adding a component adjusting material to adjust the temperature and component concentration of the molten slag as described above. When the molten slag is supplied while the slag and the component adjusting material are being supplied, there is a problem that the component concentration fluctuates greatly because the undissolved component adjusting material is mixed. On the other hand, supply of blast furnace slag, addition of component adjusting material, temperature control of molten slag and component temperature,
2. Description of the Related Art There is known a method in which two electric furnaces for performing a series of operations for tapping molten slag are installed in parallel, and tapping of molten slag is performed alternately.

According to this method, the adjustment of the component concentration and the temperature becomes easy, but in order to dissolve the component adjusting material in a short time and to improve the productivity, a melting device by stirring is required in each electric furnace. There were problems such as high equipment costs and space requirements. In addition, supply of blast furnace slag, addition of component adjusting material, primary adjustment of component concentration, electric furnace (primary electric furnace) for batch discharge of molten slag, and supply of molten slag from the primary electric furnace to mainly supply temperature of molten slag Electric furnace with the function of adjustment and secondary adjustment of component concentration (secondary electric furnace)
And a method of installing them in series is known. This method makes it easy to adjust the component concentration and temperature, and enables complete continuous tapping from the secondary electric furnace.However, if the concentration of the component needs to be changed quickly, the time lag after the primary electric furnace concentration changes. After that, the concentration of the secondary electric furnace changes,
There is a problem that it is difficult to quickly change the concentration.

The present invention efficiently stirs molten slag by gas bubbling and dissolves a component adjusting material without prematurely damaging the furnace wall of an electric furnace, eliminates breakage of a gas bubbling lance, and further improves the surface of the molten slag. It is an object of the present invention to provide a method and an apparatus for dissolving a component adjusting material in molten slag for rock wool, which can reduce the amount of power supplied to an electrode by reducing the heat dissipated from the electrode.

Further, the present invention preferably reduces the equipment cost of the component adjusting and melting apparatus by gas bubbling and reduces the number of installation places when two electric furnaces are installed in parallel or in series. It is another object of the present invention to provide an apparatus for dissolving a component adjusting material in a molten slag for rock wool, which can quickly change the component concentration of the dissolved slag.

[0013]

According to the present invention, an insertion position and an insertion angle of a gas bubbling lance immersed in a molten slag of a main raw material stored in an electric furnace, and a melting state of a component adjusting material charged on the molten slag. Experiments with various changes were repeated. As a result, they found that there were appropriate positions for the insertion position of the gas bubbling lance and the charging position of the component adjusting material, which led to the present invention, and the gist thereof was as follows. It is on the street.

According to the first aspect of the present invention, there is provided the present invention, wherein a component adjusting material is charged into a molten slag while heating a molten slag of a main raw material stored in an electric furnace by electric power supplied from an electrode. Then, in the method for dissolving the component adjusting material in the molten slag for rock wool, in which the components and the temperature of the slag are adjusted, the gas bubbling lance is substantially inserted from the lance insertion port provided at the central part of the furnace lid covering the electric furnace. Insert vertically, and immerse the lower part in the molten slag in the furnace, while passing through the cylindrical component adjusting material loading port installed on the furnace lid so as to surround from the outside concentric with the lance insertion port. Is charged on the surface of the molten slag existing around the gas bubbling lance, and the molten slag is filled in the substantially central region of the electric furnace by an inert gas blown from the gas bubbling lance. A component-adjusting material methods for dissolving rock wool for molten slag, which comprises dissolving the components adjusting material by the ring.

According to a second aspect of the present invention, the component adjusting material is introduced from a plurality of component adjusting material loading ports installed concentrically outside the lance insertion port onto the surface of the molten slag existing around the gas bubbling lance. The method for dissolving a component adjusting material in molten slag for rock wool according to claim 1, wherein the molten slag is charged in a substantially central region of the electric furnace and charged.

According to the third aspect of the present invention, the component adjusting material is charged from the inlet of the component adjusting material onto the surface of the molten slag existing around the gas bubbling lance. It promotes dissolution of the component adjusting material in the intense area, and covers more than 60% of the surface area of the molten slag without dissolving the component adjusting material in other areas except the gas bubbling area where gas bubbling is intense. The method for dissolving a component adjusting material in a molten slag for rock wool according to claim 1 or 2, wherein:

According to a fourth aspect of the present invention, while the molten slag of the main raw material stored in the electric furnace is heated by the electric power from the electrode, the molten slag is charged with a component adjusting material to adjust the slag component and the temperature. In the apparatus for dissolving the component adjusting material into the molten slag for rock wool, a lance insertion port provided at the center of the furnace lid covered with the electric furnace, and a lower portion which is vertically inserted from the lance insertion port, is provided. A gas wobbling lance immersed in a molten slag in a furnace, and a component adjusting material loading port installed on a furnace lid so as to surround the lance insertion port from the outside to a molten slag for rock wool, Is a component adjusting material melting device.

According to a fifth aspect of the present invention, there is provided a gas bubbling lance supported by a lance support portion provided at a distal end portion of a telescopic arm and connected to an inert gas source pipe via a flexible pipe, and the telescopic arm. The device for dissolving a component adjusting material in a molten slag for rock wool according to claim 4, comprising: an expansion / contraction drive device for expanding / contracting, a vertical movement drive device for vertically moving, and a turning drive device for turning. .

According to a sixth aspect of the present invention, there is provided a telescopic arm telescopic movement measuring instrument by a telescopic drive device, a telescopic arm vertical motion measuring device by a vertical drive device, and a telescopic arm turning motion by a rotary driving device. A measuring device, and a lance automatic control device for automatically adjusting the insertion, withdrawal and insertion positions of the gas bubbling lance into the lance insertion opening based on the respective measurement values measured by the measuring devices. An apparatus for dissolving a component adjusting material in a molten slag for rock wool according to claim 5.

According to a seventh aspect of the present invention, an automatic valve and a gas flow rate measuring device are installed in an inert gas supply source pipe, and a tip of a gas bubbling lance is positioned at a predetermined position in an electric furnace according to a command from an automatic lance control device. 7. The automatic valve is controlled at the timing when the temperature reaches the predetermined time, and the gas flow rate is measured by a gas flow rate measuring device to automatically blow out the inert gas, automatically blow off the gas, and control the gas flow rate. It is an apparatus for dissolving a component adjusting material in a molten slag for rock wool as described above.

According to the present invention, two electric furnaces having the same capacity are installed in parallel so as to be used alternately, and the apparatus for melting the component adjusting material in the molten slag is also used for both electric furnaces. The apparatus for dissolving a component adjusting material in molten slag for rock wool according to claim 5, which is installed. According to the ninth aspect of the present invention, the two electric furnaces are installed in series as a primary electric furnace and a secondary electric furnace, and the apparatus for melting the component adjusting material into the molten slag is arranged so as to be used for both electric furnaces. The apparatus for dissolving a component adjusting material in a molten slag for rock wool according to claim 5, 6, or 7.

[0022]

According to the present invention, a gas bubbling lance is inserted almost vertically from a lance installation inlet provided at the center of a furnace cover over an electric furnace, and the lower part thereof is immersed in molten slag in the furnace. The component adjusting material is charged from the component adjusting material loading port installed on the furnace lid so as to concentrically surround the lance insertion port on the surface of the molten slag existing around the gas bubbling lance, and from the gas bubbling lance. Inert gas is blown, and molten slag is bubbled in a substantially central region of the electric furnace.

As described above, when the lance is immersed and the molten slag is agitated by a model experiment, the lance immersed into the central portion of the electric furnace is examined by a model experiment. To stir the whole efficiently,
This is because it is optimal to position the gas inlet at the tip of the lance substantially at the center of the electric furnace. In this case, lance 1
Although the whole molten slag could be agitated by the book, if the lance tip was eccentric from the center of the electric furnace, damage to the furnace wall near the lance would be severe. Therefore, if the blowing gas flow rate is reduced in order to suppress damage to the furnace wall, an inefficient result is required in which a large number of lances need to be arranged to stir the entire molten slag. Note that this result is not simply assumed from the stirring state of a liquid having a low viscosity (1 to 5 cp) such as water or molten steel in which gas bubbling is conventionally performed, and is not assumed simply. Notable for liquids.

The lance immersed in the molten slag receives a force due to the vibration caused by the gas blowing and the movement of the deposited component adjusting material on the surface of the molten slag such as when supplying the molten slag by-produced from the blast furnace of the main raw material. When the lance is inclined and immersed, it is necessary to completely fix the other end of the lance, so it is difficult to reduce the force of the lance vibration.
In addition, since the deposited component adjusting material on the surface of the molten slag is located around the lance and a force is easily applied to the lance when supplying blast furnace slag, the lance is easily broken. On the other hand, when the lance is immersed substantially vertically, it is easy to adopt a supporting method that reduces the vibration of the lance, and because the surrounding of the lance becomes a gas bubbling area and the component adjusting material dissolves, the blast furnace slag is supplied. It is preferable because no force is applied.

By the way, in gas bubbling, there is a bubble rising region (gas bubbling region) in which the blown gas floats upward from the blowing position. When the component adjusting material is sprayed from above the molten slag and the molten slag is agitated, the melting of the component adjusting material is intense in the gas bubbling region, and the surface of the molten slag is easily exposed. Was found to be easily deposited.
Therefore, the component adjusting material is dissolved in the gas bubbling region,
A method of depositing a component adjusting material as a heat insulating layer around the periphery is effective. Such a state can be created by loading the component adjusting material from almost the center of the electric furnace, but it is more preferable to supply the component adjusting material from a plurality of locations on a concentric circle than from one location on the furnace lid of the electric furnace. Cheap.

Although the component adjusting material (generally silica powder containing a large amount of SiO ₂ ) has a low thermal conductivity and is dissolved at the contact interface between the molten slag and the component adjusting material, the silica stone powder deposited thereon becomes molten slag. Lower temperature, for example, molten slag temperature 15
The temperature of the surface of the component adjusting material deposited at 00 ° C is about 500 ° C, and the surface temperature when molten slag is exposed is 1300 ° C.
It is much lower than 1400 ℃. Therefore, by depositing the component adjusting material in an undissolved state on the surface of the molten slag, it can serve as a heat insulating material and reduce the supplied power.

Further, the heat dissipated from the surface of the molten slag changes depending on the ratio of the area B covered by the component adjusting material to the surface area A of the molten slag (area ratio = B / A), and as shown in FIG. If it is 60% or more, the effect of preventing heat dissipation becomes large, and more preferably 80% or more. Hereinafter, the configuration, operation, and effect of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the furnace lid 7 placed on the electric furnace 8
A high-temperature molten slag 9 by-produced in a blast furnace is mainly charged in a batch through a slag charging inlet (not shown) provided in the furnace, and additionally charged if necessary, and stored in an electric furnace 8. The lower part of a plurality (usually three) of the electrodes 5 inserted into the furnace through the furnace lid 7 is immersed in the molten slag 9 in the electric furnace 8, and the temperature of the molten slag 9 is kept constant by the power from the electrode 5. Heating is performed in the same manner as in the related art.

In the present invention, the gas bubbling lance 1 is inserted almost vertically from the lance insertion port 3 provided at the center of the furnace lid 7 placed on the electric furnace 8, that is, at the center position of the three electrodes 5. The lower part is immersed in the molten slag 9 in the furnace.
When the inert gas supplied from the inert gas supply pipe (not shown) through the flexible pipe 23 is supplied to the gas bubbling lance 1 and blown into the molten slag 9, the inert gas becomes bubbles 11. The gas bubbling region floats in the molten slag 9 while being formed in the central part of the furnace.

On the other hand, a component adjusting material inlet 4 is provided in the furnace lid 7 so as to surround the lance insertion port 3 from the outside so as to surround the lance insertion port 3, and the powdery and granular components supplied from the component adjusting material supply pipe 2 are provided. The adjusting material 10 is directly charged from the component adjusting material inlet 4 onto the surface of the molten slag 9 existing around the gas bubbling lance 1. In this way, the component adjusting material 10 is
The molten slag 9 in the gas bubbling region can be directly charged on the surface of the metal slag 9 because the molten slag 9 in the gas bubbling region is exposed as a bare metal surface by the spouting and stirring action. Therefore, the dissolution rate increases, and the dissolution is accelerated.

On the other hand, the component adjusting material (generally, silica powder containing a large amount of SiO ₂ ) 10 in the peripheral region pushed to the periphery by gas bubbling formed in the central portion of the electric furnace 8 is composed of Although the adjusting material 9 has low thermal conductivity, it melts at the contact interface between the molten slag 9 and the component adjusting material 10, but the component adjusting material (silica powder) 10 laid thereon has a higher temperature than the molten slag 9. Becomes low and becomes a state in which the undissolved component adjusting material 6 is deposited.

When the undissolved component adjusting material 6 is deposited on the surface of the molten slag 9 around the gas bubbling region in this way, it serves as a heat insulating layer, so that the heat dissipated from the surface of the molten slag 9 is reduced. can do. As a result, the heat retention is enhanced, and as a result, the power supplied from the electrode 5 for heating can be reduced.

In the present invention, the component adjusting material melting device 30 is shown in FIG.
And the device configuration as shown in FIG.
That is, the gas bubbling lance 1 provided in the component adjusting material dissolving device 30 is rotatably supported by the lance suspension support portion 12 provided at the distal end of the telescopic arm 13, and the telescopic arm 13 is It is supported by the arm body 13C via 13A and 13B so as to be extendable and contractible. And telescopic arm
Bearings 26A and 26B are provided between the arm 13 and the arm body 13C, respectively.
The telescopic arm 13 is extended and contracted by extending and retracting the cylinder-type telescopic drive device 14 which is supported by a shaft. The gas bubbling lance 1 is moved forward and backward.

The arm body 13C is supported so as to be vertically movable by tilting with respect to a vertically movable support member 27 via a horizontal pin 28. The arm body 13C and a vertical support member
27, a cylinder-type vertical drive device 15 is mounted, and is tilted via a horizontal pin 28 by expanding and contracting the cylinder-type telescopic drive device 15, thereby providing the distal end of the telescopic arm 13. The gas bubbling lance 1 supported by the lance support member 12 is moved up and down. In this case, the telescopic arm 13 draws an arc with the horizontal pin 28 as a fulcrum. Perform in conjunction.

Further, the up-and-down movement support member 27 is fixedly mounted on a turning table 25 having a circular plane shape, and a side surface of the turning table 25 is connected to the cylinder-type turning driving device 16. The center axis 31 is attached to the swivel 25 by extending and retracting the cylinder type swivel drive 16.
, The vertically movable support member 27 integrally provided on the revolving table 25 is revolved, whereby the gas bubbling lance 1 can be revolved between the operating position 1A and the standby position 1B. I can do it.

The amount of expansion and contraction movement by the cylinder type expansion and contraction drive unit 14 is measured by an expansion and contraction amount measurement unit 18, and the amount of up and down movement by the cylinder type expansion and contraction drive unit 15 is measured by an up and down amount measurement unit.
19, the amount of turning movement by the cylinder-type turning drive device 16 is measured by the turning movement amount measuring device 20, respectively.
These measured values are input to the lance control operation panel 21 and the gas bubbling lance 1 is automatically inserted into and removed from the lance insertion port 3 by a command from the lance control operation panel 21 while confirming the position of the gas bubbling lance 1. it can. As a matter of course, the gas bubbling 1 can be manually inserted and withdrawn by the lance control operation panel 21 as necessary.

The inert gas to the gas bubbling lance 1 is supplied to a gas flow controller provided in the inert gas supply pipe 17 by opening the shut-off valve 24 in response to a command from the lance control operation panel 21.
While adjusting the flow rate at 22, the gas passes through the gas bubbling lance 1 via the inert gas supply pipe 17 and the flexible pipe 23, and is blown into the molten slag 9 in the electric furnace 8.

Next, the operation of the present invention will be described assuming that the gas bubbling lance 1 is at the standby position 1B.
First, a predetermined amount of molten slag by-produced in the blast furnace is charged in batch from a slag supply port 29 provided in the electric furnace 8. The electrode 5 is inserted into the furnace through the furnace wall 7, immersed to a predetermined depth in the molten slag 9, and power is supplied from the electrode 5 to start heating the molten slag.

The operation of the cylinder-type turning drive device 16 is started according to a command from the lance control operation panel 21, and the telescopic arm 13 is turned while reaching the predetermined position while measuring the turning amount by the turning amount measuring device 20. Then, the operation of the cylinder-type turning drive device 16 is stopped according to a command from the lance control operation panel 21.
Next, the operation of the cylinder type telescopic drive device 14 is started according to a command from the lance control operation panel 21, and the telescopic members 3B, 3A provided on the arm main body 3C are measured while measuring the telescopic movement amount by the telescopic movement amount measuring device 18. When the telescopic arm 13 is extended via the lance control operation panel 21, the telescopic drive device 14 is stopped when it reaches a predetermined position. At this time, the telescopic arm
The gas bubbling lance 1 supported by the lance suspension support portion 12 provided at the distal end of the thirteen reaches the upper position 1A of the lance insertion port 3 provided at the central portion of the furnace lid 7 covering the electric furnace 8. .

Subsequently, the operation of the cylinder type vertical movement driving device 15 is started by a command from the lance control operation panel 21, and the vertical movement amount is measured by the vertical movement amount measuring device 19 while the gas bubbling lance is moved through the telescopic arm 13. 1 is lowered and inserted into the electric furnace 8 from the lance insertion port 3. At this time, the telescopic arm 13 draws an arc with the horizontal pin 28 connecting the arm body 13C to the vertical movement support member 27 as a fulcrum,
The gas bubbling lance 1 supported by the
The gas bubbling lance 1 is lowered by interlocking with the telescopic drive device 14 so as to coincide with the position of. If a displacement occurs in the gas bubbling lance 1 via the telescopic arm 13, the telescopic drive device is appropriately adjusted according to the positional displacement.
Needless to say, the position is corrected using the vertical drive device 15 and the turning drive device 16.

Thus, at the timing when the tip of the gas bubbling lance 1 passes a predetermined position above the molten slag 10 stored in the electric furnace 3, the shut-off valve 24 is opened according to a command from the lance control operation panel 21, and the gas flow rate is increased. The regulator 22 automatically adjusts the flow rate of an inert gas (here, nitrogen N ₂ gas), passes through the gas bubbling lance 1 via the inert gas supply pipe 17 and the flexible pipe 23, and Start blowing N ₂ gas in the bath space inside. By blowing out the N ₂ gas from the gas bubbling lance 1 at such a timing, the blowing of the N ₂ gas outside the electric furnace 8 is prevented.

[0042] Then, from the gas bubbling lance 1 N ₂
When the gas bubbling lance 1 is immersed to a predetermined depth of the molten slag 9 while blowing gas, the lance control operation panel
The vertical drive device 15 is stopped by a command from 21. Silica powder containing a large amount of powdered SiO ₂ as a component adjusting material 10 is charged from the component adjusting material supply pipe 2 into the center of the molten slag 9 via the component adjusting material inlet 4. Further, the molten slag 9 is additionally charged into the electric furnace 8 as needed. The N ₂ gas blown into the molten slag 9 from the gas bubbling lance 1 forms bubbles 11 at the center of the molten slag and floats around the lance 1 to form a gas bubbling region. Because of the bare oil surface, the charged component adjusting material can be rapidly dissolved.

On the other hand, the molten slag 9 in the peripheral region of the gas bubbling region formed in the central part of the electric furnace plays a role as a heat insulating layer because it is covered with the deposited undissolved component adjusting material 6. Radiant heat radiated from the surface of the slag 9 can be reduced. Therefore, the power supplied from the electrode 5 for heating can be reduced as described above. In this way, the silica silicate powder is uniformly dissolved as the predetermined amount of the component adjusting material 10 in the molten slag 9 stored in the electric furnace 8 and the molten slag 9 is adjusted to the predetermined temperature by the electrode 5. The gas bubbling lance 1 is withdrawn from the electric furnace 8 through the lance insertion port 3 by the procedure described in the above, and the standby position 1B
Return to standby. Further, the molten slag 9 in the electric furnace 8
After extracting the electrode 5 from the furnace, the molten slag 9 is removed from the electric furnace 8.
Is discharged into a slag pan, which is used for the production of rock wool.

The expansion / contraction driving device 14 and the vertical movement driving device 15 provided in the component adjusting material melting device 30 shown in FIGS.
The case where a cylinder type is used as the swing drive device 16 has been described.However, the present invention is not limited to this, and it is possible to use a well-known expansion / contraction, vertical movement, and swing drive device such as a rack and pinion mechanism, an electric actuator, and the like. Can be. The vertical drive unit may be configured such that the vertical carriage is moved up and down by the drive unit along the vertical guide post, so that the gas bubbling lance supported by the distal end of the telescopic arm may be moved up and down. It is possible.

FIG. 4 shows two electric furnaces 8A and 8B.
It is an arrangement view showing a plane in the case of installing in parallel. FIG.
As shown in the figure, the furnace lid 7 covering the electric furnace 8A and the electric furnace 8B has a lance insertion port 3 for inserting the gas bubbling lance 1, a component adjusting material inlet 4 for charging the component adjusting material into the furnace, and A slag supply port 29 for charging molten slag by-produced from the blast furnace into the furnace is provided, and three electrodes 5 are charged into the furnace via the furnace lid 7. Further, the telescopic arm 13 is supported on the arm body 13C via telescopic members 13A and 13B so as to be able to expand and contract.

Further, one telescopic arm 13 is operated by the same cylinder type telescopic drive unit 14, cylinder type up / down drive unit 15, cylinder type swivel drive unit 16 and the like as shown in FIGS. One component adjusting material melting device 30
Are alternately used for the two electric furnaces 8A and 8B. Slag supply port to electric furnace 8A
The molten slag is charged from 29, the gas bubbling lance 1 is inserted from the lance insertion port 3, the component adjusting material is charged from the component adjusting material inlet 4, and the component adjustment of the molten slag, the slag temperature adjustment by the electrode 5, and A series of operations for tapping molten slag are performed.

After a series of operations of the electric furnace 8A is completed, a series of operations are similarly performed on the electric furnace 8B to alternately dissolve the component adjusting material in the molten slag and discharge the molten metal. In this manner, the slag melting apparatus 30 can alternately melt the component adjusting material by gas bubbling by installing one slag melting apparatus 30 for the two electric furnaces 8A and 8B. For this reason, the installation place of the slag melting apparatus 30 can be reduced, and the equipment cost of the melting apparatus 30 can be suppressed low, and rock wool can be stably stabilized without lowering the melting ability of the component adjusting materials of the electric furnaces 8A and 8B. Production of molten slag for use.

FIG. 5 is a layout diagram showing a plane when two electric furnaces 8C and 8D are installed in series. Primary electric furnace 8
In C, a series of operations are performed after adjusting the component concentration and the temperature by charging the component adjusting material to the molten slag stored in the furnace, and then tapping the molten slag. Further, in the secondary electric furnace 8D, the molten slag from the primary electric furnace 8C is received mainly from the slag charging inlet 29 and the temperature of the molten slag stored in the furnace is adjusted by the electrode 5, and the secondary electric furnace 8D is used as necessary. Adjust the components.

The component adjusting material melting device 30 is usually continuously inserted into the primary electric furnace 8C to melt the component adjusting material. However, when the component concentration needs to be changed quickly, it is temporarily stopped. The melting device 30 is inserted and changed into the secondary electric furnace 8D, the component concentration of the molten slag in the secondary electric furnace 8D is changed, and then the melting device 30 is returned to the primary electric furnace 8C. When increasing the component concentration of the secondary electric furnace 8D, the component concentration of the primary electric furnace 8C is raised as much as possible and then the molten metal is discharged into the secondary electric furnace 8D and the molten slag in the secondary electric furnace 8D is melted. The component adjusting material added supplementarily is dissolved while stirring with the device 30 to increase the component concentration in the secondary electric furnace 8D. When lowering the component concentration of the secondary electric furnace 8D, the stirring of the primary electric furnace 8C is stopped, the component concentration is reduced as much as possible before the hot water is discharged to the secondary electric furnace 8D, and the secondary electric furnace 8D is placed in the secondary electric furnace 8D. The molten slag is stirred by the melting device 30 without adding the component adjusting material to lower the component concentration in the secondary electric furnace 8D. According to this device,
Primary electric furnace 8C and secondary electric furnace 8D using melting device 30
Can be agitated as needed, so that the installation space is small, the equipment cost of the melting device 30 can be kept low, the component concentration in the final secondary electric furnace 8D can be quickly changed, and flexible production can be performed.

[0050]

Embodiments of the present invention will be described below. Example 1 35 tons of molten slag by-produced from a blast furnace were stored in an electric furnace 8 having the structure shown in Fig. 1, and 7 tons of molten slag and 1.2 tons of silica stone powder as a component adjusting material were mounted in a cycle of about 40 minutes. The molten slag was charged from the inlet and supplied with power of 1200 kwh from the electrode 5 to adjust the components and temperature of the molten slag while heating the molten slag.

At this time, the gas bubbling lance supported on the distal end of the telescopic arm by a command from the lance control operation panel 21 using the melting device 30 having the telescopic, vertical movement and swiveling mechanisms shown in FIGS. The molten slag in the furnace is gas-bubbled at the center of the furnace at a nitrogen gas flow rate of about 6 m ³ / hr from the gas bubbling lance 1 to insert a predetermined component. 8.2 tons of molten slag having a concentration and a predetermined temperature was discharged from the electric furnace 8.

In the present invention, the operation time of one cycle by the electric furnace 8 is adjusted in accordance with the production amount of rock wool, and when the production amount is small, the gas bubbling lance 1 provided in the melting device 30 is not used. It is preferable to use the gas bubbling lance 1 provided in the dissolving device 30 when the production volume is large and to adjust the flow rate of the nitrogen gas blown from the lance according to the production volume of rock wool.

During this time, the timing of inserting and extracting the gas bubbling lance 1 into the furnace, blowing out and shutting off nitrogen gas is automatically performed according to a command from the lance control operation panel 21, and according to the amount of molten slag in the electric furnace 8. Thus, the immersion depth of the gas bubbling lance 1 in the molten slag was adjusted.
35 tons of molten slag are stored in the same electric furnace 8, and 7 tons of molten slag by-produced from the blast furnace and 1.2 tons of silica powder as a component adjusting material are charged in a cycle of about 80 minutes. By bubbling less,
2000 kwh of electric power was supplied from the electrode 5 to heat the molten slag and adjust the components and temperature of the molten slag.
Approximately 8.2 tons of molten slag adjusted to a predetermined component concentration and a predetermined temperature in the electric furnace 8 in this way was discharged.

According to the present invention, the power consumption can be greatly reduced as compared with the case where gas bubbling is not performed. Example 2 As shown in FIG. 5, 35 tons of molten slag were stored in a primary electric furnace 8C, 7 tons of blast furnace slag and silica powder as a component adjusting material.
Charge 1.2 tons, and supply 8.2 tons of molten slag of the primary electric furnace 8C to the secondary electric furnace 8D. In the meantime, FIG.
And the mixture was stirred by the gas bubbling lance 1 of the dissolving apparatus 30 shown in FIG. Normally, the secondary electric furnace 8D stores 20 tons of molten slag, receives 8.2 tons of molten slag, and continuously discharges molten slag having a SiO ₂ concentration of 41% without adding a component adjusting material. When increasing the SiO ₂ concentration to 43% to change the product type, etc., the conventional method required about 100 minutes from the start to the end of the change, but the method of the present invention, that is, the component adjusting material to the primary electric furnace 8C was used. A method in which the supply amount is increased and the SiO ₂ concentration of the primary electric furnace 8C is increased, and a component adjusting material is additionally added to the secondary electric furnace 8D to temporarily use the melting apparatus 30 in the secondary electric furnace 8D. Now, it has been reduced to about 20 minutes from the start to the end of the change. When the SiO ₂ concentration was reduced from 43% to 41%, the conventional method required about 130 minutes from the start to the end of the change, but the method of the present invention, that is, the supply amount of the component adjusting material to the primary electric furnace 8C was reduced. In the method in which the SiO ₂ concentration in the primary electric furnace 8D is lowered and the melting device 30 is temporarily used in the secondary electric furnace 8D to actively stir, the time from the start to the end of the change is reduced to about 40 minutes. As a result, efficient stirring can be performed with one dissolving device 30 in accordance with the concentration change condition, the time required to change the component concentration can be shortened, and more flexible production than before can be achieved.

[0055]

As described above, according to the present invention, a gas bubbling lance is inserted almost vertically from a lance insertion port provided at a central portion of a furnace cover over an electric furnace, and a lower portion thereof is inserted into the furnace. While being immersed in the molten slag, the component adjusting material is introduced from a cylindrical component adjusting material charging port installed in the furnace lid so as to surround from the outside concentrically with the lance insertion port. An inert gas was blown from the gas bubbling lance on the surface and the molten slag was bubbled in a substantially central region of the electric furnace to dissolve the component adjusting material.

As a result, bubbles of the inert gas blown into the molten slag from the gas bubbling lance immersed in the central portion of the electric furnace are formed in the gas bubbling region in the central portion of the molten slag around the lance. Since the component adjusting material is mainly charged in the region where the surface of the molten slag is exposed, the dissolution thereof can be promoted. Further, since the undissolved component adjusting material is deposited on the molten slag in the peripheral region of the gas bubbling region, the heat dissipated from the molten slag can be reduced. In addition, since the temperature in the center of the electric furnace is relatively high while the temperature in the periphery is low, damage to the electric furnace wall can be suppressed. Since the gas bubbling lance is almost vertically immersed in the molten slag, lance vibration due to gas bubbling is small. For this reason, the lance is not broken, and the melting of the component adjusting material can be efficiently achieved by gas bubbling agitation with the molten slag. Become.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a main part of an apparatus according to the present invention.

FIG. 2 is a sectional view showing the overall arrangement of the device according to the present invention.

FIG. 3 is a plan view of the device according to the present invention.

FIG. 4 is a plan view of an apparatus according to another embodiment of the present invention.

FIG. 5 is a plan view of an apparatus according to another embodiment of the present invention.

FIG. 6 is a diagram showing a relationship between a coating area of an undissolved component adjusting material and heat dissipation.

FIG. 7 is a sectional view showing a device according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gas bubbling lance 2 Component adjustment material supply pipe 3 Lance insertion port 4 Component adjustment material loading port 5 Electrode 6 Undissolved component adjustment material 7 Furnace lid 8 Electric furnace 9 Melted slag 10 Component adjustment material 11 Bubbles 12 Lance hanging support 13 Expansion and contraction Arm 14 Telescopic drive (cylinder type) 15 Vertical drive (cylinder type) 16 Swivel drive (cylinder type) 17 Inert gas supply pipe 18 Telescopic mover 19 Vertical mover 20 Rotary mover 21 Lance control operation panel 22 Gas flow controller 23 Flexible pipe 24 Shut-off valve 25 Swivel table 26 Bearing 27 Vertical support member 28 Horizontal pin 29 Slag supply port 30 Component adjusting material melting device 31 Central shaft

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Norio Misaki 1-chome, Kawasaki-dori, Mizushima, Kurashiki-shi, Okayama Pref. 1-chome (without address) Inside the Mizushima Works of Kawasaki Steel Corporation (56) References JP-A-4-126822 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C04B 5/00 -5/06 C21C 5/06 C21C 5/28 C03B 37/00

Claims (9)

(57) [Claims] 1. A lock for heating a molten slag of a main raw material stored in an electric furnace with electric power supplied from an electrode, charging a component adjusting material to the molten slag, and adjusting a component and a temperature of the slag. In the method for dissolving a component adjusting material in a molten slag for wool, a gas bubbling lance is inserted almost vertically from a lance insertion port provided in a central portion of a furnace cover over the electric furnace, and a lower portion thereof is melted slag in the furnace. While immersed in the lance insertion hole, the component adjustment material is introduced from a cylindrical component adjustment material loading port installed in the furnace lid so as to surround from the outside concentrically with the lance insertion port on the surface of the molten slag existing around the gas bubbling lance. Dissolving the component adjusting material by bubbling molten slag in a substantially central region of the electric furnace by using an inert gas blown from the gas bubbling lance. A method for dissolving a component adjusting material in a molten slag for rock wool, the method comprising: 2. A method of charging an electric furnace, wherein a component adjusting material is charged onto a surface of a molten slag existing around a gas bubbling lance through a plurality of component adjusting material loading ports installed on concentric circles outside a lance insertion port. 2. The method for dissolving a component adjusting material in molten slag for rock wool according to claim 1, wherein the molten slag is bubbled in a substantially central region. 3. A component adjusting material is charged from a component adjusting material charging inlet onto a surface of a molten slag existing around a gas bubbling lance, and the component adjusting material is set in a substantially central portion of the electric furnace in a region where gas bubbling is severe. Dissolving of the slag is promoted, and the component adjusting material existing in the other region except the gas bubbling region where gas bubbling is intense covers at least 60% of the surface area of the molten slag without being dissolved. Item 4. The method for dissolving a component adjusting material in molten slag for rock wool according to Item 1 or 2. 4. A rock wool for heating a molten slag of a main raw material stored in an electric furnace with electric power from an electrode and charging a component adjusting material to the molten slag to adjust a slag component and a temperature. In the apparatus for dissolving the component adjusting material in the molten slag, a lance insertion port provided at the center of the furnace lid over the electric furnace, and vertically inserted from the lance insertion port, and a lower portion thereof is inserted into the molten slag in the furnace. An apparatus for dissolving a component adjusting material in a molten slag for rock wool, comprising: a gas bubbling lance soaked; and a component adjusting material loading port installed in a furnace lid so as to surround the lance insertion port from the outside. 5. A gas bubbling lance supported by a lance support portion provided at a distal end of a telescopic arm and connected to an inert gas source pipe via a flexible pipe, and a telescopic drive device for expanding and contracting the telescopic arm. 5. The apparatus for dissolving a component adjusting material in a molten slag for rock wool according to claim 4, further comprising a vertical drive device for vertically moving and a turning drive device for turning. 6. A telescopic arm telescopic movement amount measuring device by a telescopic drive device, a telescopic arm vertical movement amount measuring device by a vertical driving device, a telescopic arm turning movement measuring device by a rotary driving device, and each of the measurements 6. An automatic lance control device for automatically adjusting the insertion, withdrawal and insertion positions of the gas bubbling lance into and out of the lance insertion port based on the respective measured values measured by the measuring device.
An apparatus for dissolving a component adjusting material in a molten slag for rock wool as described in the above. 7. An automatic valve and a gas flow measuring device are installed in an inert gas supply source pipe, and the automatic valve is operated at a timing when a tip of a gas bubbling lance reaches a predetermined position in an electric furnace according to a command from an automatic lance control device. 7. The molten slag for rock wool according to claim 6, wherein the gas flow rate is measured by a gas flow rate measuring device, and the inert gas is automatically blown out, automatically blown off, and the gas flow rate is controlled. Equipment for dissolving component adjusting materials. 8. Two electric furnaces having the same capacity are installed in parallel so as to be used alternately, and a device for melting a component adjusting material in molten slag is arranged so as to be used for both electric furnaces. The apparatus for dissolving a component adjusting material in a molten slag for rock wool according to claim 5, 6 or 7. 9. The method according to claim 1, wherein two electric furnaces are installed in series as a primary electric furnace and a secondary electric furnace, and a device for melting the component adjusting material in the molten slag is installed so as to be used for both electric furnaces. The apparatus for dissolving a component adjusting material in a molten slag for rock wool according to claim 5, 6 or 7.