JP2002275554A - Method for heat-insulating converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for heat-insulating a converter in which the converter can be favorably heat-insulated when the operation is stopped. SOLUTION: In this method, solid fuel is burned in the converter 1 when the operation is stopped, and/or flame 7 of liquid or gas fuel is blown from a tuyere 3 into the converter, and/or the tuyere 2 is covered by a converter lid 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for keeping a converter warm.

[0002]

2. Description of the Related Art In a smelting operation for melting copper hot water using a converter, (Cu, Fe) S produced in a mat smelting furnace such as a flash smelting furnace is used.
(Mainly referred to as “kawa”; copper grade 63 ~)
A silicate ore containing SiO2 as a main component and a pierce-smith type cylindrical horizontal converter 1 capable of tilting in the circumferential direction as shown in FIG. A passage hole for extracting reaction products and the like in the furnace. Also referred to as a charging port or a work port.) Air or oxygen is charged into the furnace through a tuyere 3 composed of nozzles arranged at the lower part of the furnace body. Enriched air
10 is blown in, and after a brewing period, and then a copper making period (also called a copper making period), a copper hot water (also called "kane"; copper grade of about 99%) is melted.

[0003] In the period of irrigation, mainly the formula (1):
The reaction of 2 (Cu, Fe) S + 2O ₂ + SiO ₂ → Cu ₂ S + 2FeO · SiO ₂ + SO ₂ is promoted, and a solution of white glue mainly composed of Cu ₂ S and 2FeO · SiO 2
The main slag (also called "kan" or "karami")
Then, sulfur dioxide gas (SO ₂ ) is generated, and when a predetermined reaction is completed, the blowing of air or the like is stopped. The white rice is kept in the furnace and becomes a raw material for the copper making stage of the next process. The slag floating on the surface of the white water with a specific gravity smaller than that of the white water is discharged from the furnace port 2 to the outside of the furnace by appropriately tilting the converter 1. Sulfurous acid gas generated during operation, i.e., during blowing, is discharged out of the furnace from a hood 4 provided to cover the furnace port 2, and sensible heat is sent to a sulfuric acid factory while being recovered by a converter waste heat boiler 30 and the like. Can be
When the converter 1 is tilted, the front movable hood 4A of the hood 4
Is lifted and the furnace port 2 is opened.

In the copper making period, mainly the formula (2): Cu
The reaction of ₂ S + O ₂ → Cu + SO ₂ is promoted, and copper hot water A substantially composed of Cu and sulfurous acid gas are generated. In addition, a small amount of a residual B containing a copper component mainly composed of Fe ₃ O ₄ having a higher melting point and a lower specific gravity than the copper melt is generated and floats on the copper melt surface. After the end of the copper making period, the copper hot water is transferred to the refining furnace of the next process via a ladle to be refined into blister copper with a higher copper grade (about 99.4%). The remnants are left in the furnace when the copper melt is discharged, and are treated during the fermentation period for the newly charged mat. Sulfurous acid gas is discharged from the hood 4 in the same manner as during the period of making.

[0005]

In a converter for smelting copper melt, operation adjustment and equipment troubles in a converter smelting furnace process, a refining furnace process, a sulfuric acid production process, etc., which are processes before and after the converter process, and troubles in the process. Melting (operation) may be interrupted due to restoration work. If the operation is interrupted for a short period of time, the supply of oxygen-containing gas from the tuyere is stopped, and if left as it is, the temperature of the solution such as copper bath and mat in the furnace falls below the appropriate reaction temperature. This will hinder restarting operations. Also, if the interruption is for a long period of time, unless the converter waste heat boiler or sulfuric acid plant has any problems, the copper melt is discharged from the converter after the copper making period, and the furnace is left empty. However, as it is, the reaction in the slag is not smoothly performed in the next fermentation period due to a decrease in the furnace temperature. Further, the residue adheres to the bricks in the furnace, and the volume in the furnace is reduced.

[0006] Therefore, in the converter during the cold wind, the mat,
During the operation of the converter excluding the period of taking in and out the solution such as copper hot water, it is possible to use a burner to blow liquid or gas fuel flame such as kerosene from the tuyere through the tuyere to keep the inside of the furnace empty or the remaining solution. Is being done. This method of insulating the converter by injecting a liquid or gaseous fuel flame is effective, but in the case of long-term heat insulation, a decrease in the furnace temperature is unavoidable. The tuyere position must be raised to prevent backflow of the solution
Setting the burner to the tuyere is not preferable for work safety,
There was a problem.

Accordingly, an object of the present invention is to provide a converter insulation method capable of more advantageously maintaining the converter insulation during a relatively long operation interruption.

[0008]

The above object has been attained by the present invention having the following points. (1) A method for keeping a converter warm, comprising burning solid fuel in the converter when the operation of melting copper hot water using the converter is interrupted. (2) Insulation of the converter characterized by burning solid fuel in the converter and blowing liquid or gas fuel flame from the tuyere into the converter when the operation of melting copper hot water using the converter is interrupted. Method.

(3) A method for keeping a converter warm, characterized by burning solid fuel in the converter when the operation of melting the copper melt using the converter is interrupted and covering the furnace opening of the converter with a furnace lid. . (4) When the operation of melting copper hot water using the converter is interrupted, solid fuel is burned in the converter while liquid or gas fuel flame is blown into the converter from the tuyere, and the furnace outlet of the converter is closed. A converter insulation method comprising covering with a furnace lid.

[0010]

DETAILED DESCRIPTION OF THE INVENTION In the present invention, a method of burning solid fuel (excluding wood such as firewood) in a converter when operation is interrupted, or blowing liquid or gaseous fuel flame into the converter from tuyeres. Alternatively, when the operation is interrupted, the solid fuel is burned, a liquid or gas fuel flame is blown into the converter from the tuyere, and the furnace opening of the converter is covered with a furnace lid.

When a solid fuel containing carbon as a main component, such as coke or coal, is charged into a converter, the converter floats and covers the surface of the furnace if there is a solution. However, the surface of the refractory near the center of the furnace is covered to prevent heat dissipation from the furnace port and to heat the surface to prevent the temperature of the furnace melt or the refractory inside the furnace. Coke or coal with a water content of 15% by mass or less is used as a solid fuel.
It is preferable because there is no danger of steam explosion in the furnace and it is easy to handle and inexpensive.

[0012] These solid fuels may be charged from the furnace port using a chute or the like for charging silicate ore or the like into the furnace, or may be loaded on a charging boat and used for the furnace using an overhead crane. The whole amount may be charged into the furnace at one time from the mouth. It is also possible to blow fine powdery solid fuel from the tuyere.
Since the solid fuel has a lower combustion rate than the liquid or gas fuel, it is preferably used when the operation of the converter is interrupted for 1 hour or more, particularly 3 hours or more. When using solid fuel, it is important to adjust the charge so that it burns out during the suspension time. This is because solid fuel has a low specific gravity, so if a large amount of solid fuel is left inside the furnace and air is blown, red-hot unburned solid fuel will blow out of the furnace and cause fires around the converter. This is because the smoke in the converter waste heat boiler may ignite and cause problems such as hindrance to the operation. For example, calorific value about 8500kcal / k
When 500 kg of oil coke containing g, 9 to 12% of volatile matter, 0.1 to 0.3% of ash, and 8% of water is charged into the furnace, it takes about 5 to 10 hours to burn out.

When the solid fuel is charged from the furnace port, if the particle diameter is too small, the proportion of the solid fuel scattered outside the furnace at the time of charging due to the rising air current from the furnace port increases. It is preferable to use a solid fuel having a mass ratio of 0.5 mm or more and 90% or more. More preferably, it is sieved to a particle size of 3
It is preferable that the proportion of the solid fuel in the range of up to 70 mm is 90% or more by mass. If the particle size exceeds 100 mm, the effect of coating the solution or the like is reduced, and the burning rate is further decreased, which is not preferable.

[0014] Injection of pulverized coal of less than 3 mm from the tuyere using a burner does not completely burn in the furnace due to its slow burning rate, and increases the rate of afterburning out of the furnace. Further, since the solid fuel has a low burning rate as described above, it is preferable to simultaneously blow a liquid or gaseous fuel flame from the tuyere in order to increase the heat retaining effect.

In order to further ensure the heat retaining effect, it is preferable to cover the furnace port with a furnace lid. Due to the attachment of the furnace lid, heat dissipation from the furnace port is effectively suppressed, and the insulative power in the furnace is enhanced. As the liquid fuel, kerosene, fuel oil A, or the like, which has good handleability and has high combustion efficiency even with a furnace lid, can be preferably used. In addition, as the gaseous fuel, liquefied petroleum gas, propane, butane, a mixed gas of propane and butane, ammonia gas, and the like, which have good handleability and good combustion efficiency like liquid fuel, can be preferably used.

The refractory in the converter can be efficiently heated and heated by burning the solid fuel in the converter after the furnace repair and covering the furnace opening with a furnace lid. In addition, at least one of the solid fuel, liquid fuel, and gas fuel is burned in the converter after the furnace repair, and the furnace opening is covered with a furnace lid to efficiently heat the refractory in the converter. The temperature can be raised.

The furnace lid is preferably of a size capable of covering the entire opening of the furnace port, and its shape is not particularly limited.
A shape as simple as possible from the viewpoint of ease of production and ease of attachment / detachment, for example, a shape obtained by cutting off a part of a cylindrical wall having an inner surface shape following the outer shape of the converter as shown in FIG. 3 is desirable. . Further, the furnace lid 5 is preferably formed of a composite of a steel material and a refractory from the viewpoints of strength, heat resistance and the like. For example, as shown in FIG.
What is formed by constructing is preferred. It is preferable that an anchor for supporting the irregular-shaped refractory 5B is provided in the steel frame 5A. The furnace lid 5 is installed at the furnace opening 2 with the irregular-shaped refractory 5B facing the inside of the furnace. The furnace lid 5 is appropriately provided with a support column 51 for preventing the mounting position from being displaced from the furnace port when the converter is tilted or the converter is tilted as shown in FIG.
Is preferably provided. In the case of a furnace lid having such columns, for example, when a solution is contained in a converter,
Even if the furnace port surface is inclined more than horizontal, the converter can be tilted while covering the furnace port, and the degree of freedom of operation is not impaired.

The furnace lid can be attached to and detached from the furnace port using an overhead crane. However, since it is a general purpose, it may be difficult to use it immediately in an emergency. Further, it is difficult to position the furnace lid suspended by the overhead crane with the furnace opening, which places a heavy burden on the overhead crane operator. Because of these difficulties, it is preferable to use a dedicated attachment / detachment device separately. For example, as shown in FIG. 1 to FIG. 2, a furnace lid 5 that detachably covers the furnace port 2 of the converter 1 for melting copper hot water, and the furnace lid 5 that can be moved up and down. A converter furnace cover device having a furnace cover attaching / detaching machine 6 which is held and attached to and detached from the furnace port 2 at a fixed position is preferable. According to this device, the attachment and detachment of the furnace lid can be automated, and the burden on the overhead crane operator and the like can be reduced.

The furnace lid attaching / detaching machine 6 of this embodiment includes a wire 6D for suspending the furnace lid 5, a pulley 6C for guiding the wire 6D, a feeding / unloading machine 6B for feeding or feeding the wire 6D, and the pulley 6C. And an arm 6A for supporting the feeding / unloading machine 6B, and a rotary support shaft 6E for supporting the arm 6A and rotating by 90 ° from a position immediately above the furnace port 2 at a fixed position to a standby position obliquely above the furnace port 2.
And The feeding and unloading operation of the feeding and unloading machine 6B and the rotating spindle
6E arm 6A rotation operation is a motor (not shown)
, And the motor is operated by button operation.

The converter furnace cover device 6 is operated, for example, as follows. 1) After the front movable hood 4 retreats when the operation is interrupted (or stopped), coke is charged into the furnace from the furnace port using an overhead crane according to the heat retention time. 2) Adjust the tilt angle of the converter so that it comes to a fixed position for closing the furnace. Normally, the angle formed between the surface of the furnace port at the fixed position and the ground is a predetermined position selected from a horizontal angle or an angle at which the surface of the furnace port is inclined by about 50 ° toward the solution discharge side (the counter tuyere side). . The furnace lid can be covered even if the furnace port is shifted from the home position back and forth by, for example, about 15 °.

3) The arm 6A is turned downward by 90 ° and lowered to a horizontal position. As a result, the furnace lid 5 is carried from the standby position obliquely above the converter 1 to a position vertically above the furnace port 2 at a fixed position. The attitude of the furnace lid 5 may be horizontal or slightly inclined. This is because, even if the furnace lid and the surface of the furnace port are not in a parallel relationship, if the wire is loosened, the furnace cover covers the furnace port. 4) Pay out the wire 6D. This lowers the furnace lid 5 and covers the furnace port 2.

5) When there is no solution in the furnace, the converter is tilted to an angle at which the burner can be easily inserted from the tuyere. This state is maintained during operation interruption. The flue gas is discharged from the exhaust
Is discharged from. 6) Before restarting the operation, the converter is tilted to return the furnace port to a predetermined home position, the wire 6D is inserted, the furnace cover 5 is raised, and the arm is raised.
Pull to 6A and fix.

7) Rotate the arm 6A upward by 90 ° to return the furnace lid 5 to the standby position. As described above, according to the converter furnace cover device of the present invention, the work of attaching and detaching the furnace cover to the furnace port can be performed extremely easily. By the way, in this example, the rotation angle of the arm is
Although the rotation direction is set to 90 ° and the rotation direction is set to the vertical direction (rotation in the vertical plane), the present invention is not limited to this, and the rotation angle and direction may be set appropriately according to the case.

When the rotation direction is the vertical direction, the rotation angle is preferably in the range of 60 to 120 °. If the rotation angle is less than 60 °, the mat interferes with the ladle to be charged into the furnace from the furnace port, which is not preferable.On the other hand, if the rotation angle is more than 120 °, it takes too much time to cover the furnace lid, and measures against pollution are required. It is not preferable because it interferes with the side surface of the hood that seals the leakage of sulfurous acid gas installed.

When a solution is contained in the furnace, the temperature may be kept at a position where the furnace port is shifted from a fixed position to a solution discharge side (opposite the tuyere side) so that the tuyere is not immersed in the solution. In this case, as shown in FIG. 2, the column 51 attached to the tuyere side of the furnace lid 5 allows the furnace lid 2 to be stably mounted on the furnace port 2.

[0026]

EXAMPLES (Example 1) During the first canning operation in a converter with a production volume of 210 tons / lot of copper hot water, a trouble in another process after charging the cold material forced an interruption of the operation for 3 hours. Therefore, according to the present invention, the calorific value is 8500 kcal / kg, the water content is 8%, and the particle size is 10% to 30mm.
300 kg of oil coke (amount that almost burns out in 3 hours) is charged all at once from the furnace mouth to the furnace by a boat using an overhead crane, and kerosene is 50 l / h from the tuyere while the operation is suspended. By continuously blowing the two furnaces, the coke in-furnace solution coating and combustion heat of coke and the heat retention in the converter by the combustion heat of kerosene were performed.

As a result, it was possible to carry out the slag making operation without any trouble after the restart of the operation, and there was no particular problem with the slag fluidity. (Example 2) After the copper making operation in a converter with a production volume of 210 tons / lot of copper hot water, a trouble in another process forced the interruption of the operation for 7 hours. Therefore, according to the present invention, after the copper melt is discharged to the ladle, the mass ratio in the range of particle diameter 10 to 25 mm
500 kg of 100% oil coke (amount almost burned out in 7 hours) was loaded into the furnace at once from the furnace port using a ceiling crane by a boat, the furnace lid was closed, and kerosene was supplied from the tuyere while the operation was suspended. By continuing to blow the inside of the furnace with two 45 l / h burners, the refractory coating of coke and the combustion heat, and the heat retention in the converter by the combustion heat of kerosene were carried out.

The heat retention by the furnace lid was carried out in the manner shown in FIGS. The furnace opening size of this converter was furnace width in the circumferential direction = 2000 mm and furnace length direction width = 2700 mm, so that the outer dimensions of the furnace lid were designed so that the furnace opening could be covered with a margin. , Furnace width in the circumferential direction = 2540 mm, furnace width in the length direction = 2800 mm,
The thickness was 200 mm. For the refractory of the furnace lid,
Yotai Casco C-140-SC30 manufactured by Yotai Corporation was used. The furnace lid was provided with two columns of 75mmφ × 300mm length and two 250mm square exhaust holes. Regarding the furnace lid attaching / detaching machine, the arm and the rotating column were made of steel, and a normal drum winding type was used as the feeding / unloading machine.

As a result, the operation for the next batch in the period of making could be performed without adjusting the amount of the cooling material.

[0030]

According to the present invention, when the operation of the converter is interrupted, the solid fuel covers and heats the solution or refractory in the converter in response to long-term heat-retaining needs, thereby increasing the heat-retaining effect.
In addition, by installing a furnace lid at the furnace opening of the converter, the heat retention effect is further enhanced, and it becomes possible to always perform a stable converter operation without changing the operating conditions after restarting,
The remnants can be prevented from sticking to the bricks in the furnace, and various effects can be obtained in that the furnace volume can be kept substantially constant.

[Brief description of the drawings]

FIG. 1 is a front view showing an outline of a converter furnace cover device.

FIG. 2 is a view taken in the direction of arrows AA in FIG. 1;

FIG. 3 is a three-dimensional view showing an example of a furnace lid.

FIG. 4 is an explanatory view of a general converter copper melting method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Converter 2 Furnace port 3 Tuyere 4 Hood 4A Front movable hood 4B Rear movable plate 5 Furnace lid 5A Steel frame 5B Irregular refractory 6 Furnace lid attaching / detaching machine 6A Arm 6B Feeding / unloading machine 6C Pulley 6D Wire 6E Rotating spindle 7 Liquid or gas fuel flame (eg kerosene flame) 10 Air or oxygen-enriched air 30 Converter waste heat boiler 51 Prop 52 Smoke outlet

Continued on the front page (72) Inventor Nobuyuki Furui 6-1-1 Hibi, Tamano-shi, Okayama Pref. Mitsui Kinzoku Mining Co., Ltd. Hibiki Refinery (72) Inventor Akira Yamashita 6-1-1 Hibi, Tamano-shi, Okayama Pref. 1 Mitsui Mining & Smelting Co., Ltd. Hibiki Refinery (72) Inventor Kimihiro Shimokawa 6-1-1 Hibi, Tamano-shi, Okayama Pref. GA06 4K070 DA01

Claims (4)

[Claims] 1. A method for keeping a converter warm, wherein solid fuel is burned in the converter when the operation of melting the copper melt using the converter is interrupted. 2. A converter characterized by burning solid fuel in a converter and blowing a liquid or gas fuel flame from a tuyere into the converter when the operation of melting copper melt using a converter is interrupted. Furnace insulation method. 3. A method for keeping a converter warm, comprising: burning solid fuel in the converter when the operation of melting the copper melt using the converter is interrupted; and covering a furnace opening of the converter with a furnace lid. 4. When the operation of melting copper hot water using a converter is interrupted, solid fuel is burned in the converter and a liquid or gas fuel flame is blown into the converter from tuyeres. A converter insulation method comprising covering a mouth with a furnace lid.