JP2002275553A - Method for heat-insulating converter, and converter lid device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for heat-insulating a converter and a converter lid device in which the converter can be favorably heat-insulated when the operation is stopped. SOLUTION: In this method, a nose 2 is covered by a converter lid 5 when the operation is stopped. A method for blowing flame 7 of liquid or gas fuel from a tuyere 3 into the converter, and covering the nose 2 by the converter lid 5 is more preferable. The converter lid device having a converter lid attaching/detaching machine 6 for holding the converter lid in an elevating/ lowering manner and attaching/detaching the converter lid to/from the nose at the predetermined position is preferably used for the covering work by the converter lid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a converter insulation method and a converter lid device.

[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 ~)
For example, as shown in FIG. 4, a silicate ore mainly composed of SiO ₂ and a pierce-smith type cylindrical horizontal converter 1 capable of tilting in the circumferential direction, a furnace port 2 (charging of raw materials, etc.) And 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 air is introduced from a tuyere 3 comprising nozzles arranged at the lower part of the furnace body. Oxygen-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]

The sulfurous acid gas generated during the operation of blowing air or oxygen-enriched air 10 from a tuyere 3 of a converter for melting copper hot water into a molten mat or the like is supplied to a sulfuric acid plant as described above. Sent and decontaminated. By the way, in the converter operation using only one furnace, sulfurous acid gas is not continuously sent to the sulfuric acid factory, but when charging the mat into the converter, when discharging the converter slag after the completion of the fermentation period, During the discharge of copper hot water after the end of the copper making period, during standby for operation due to operation adjustment, etc. (hereinafter referred to as “cool wind”), the supply of sulfurous acid gas to the sulfuric acid plant is stopped, and the operation of the sulfuric acid plant is unstable Becomes

For this reason, usually, a plurality of converters are operated,
While one furnace is in the iron making or copper making period, the other furnace is kept in a closed state, and the sulfuric acid gas is constantly supplied to the sulfuric acid plant so that the maximum concentrated sulfuric acid can be produced with the minimum sulfuric acid production equipment. An operation mode is adopted. The period of time when the other furnace is in a calm state is about 5 to 300 minutes during normal operation without any special operation adjustment or equipment trouble. Therefore, during this calm state, the temperature of the solution in the furnace, such as copper hot water, white glue, and mats, will decrease over time, and the refractory temperature in the furnace will decrease even if there is no solution in the furnace, When the mat for the next batch is received, the mat solution temperature drops, and it is necessary to adjust the amount of cold material every time to keep the furnace solution temperature constant during the ironing or coppermaking period. was there.

[0007] Further, in a converter for smelting copper hot water, operation adjustments 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, as well as repair work thereof, etc. Therefore, smelting (operation) may be interrupted. 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.

[0008] Therefore, in the converter during the cold season, 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 blowing liquid or gaseous fuel flame is effective.However, in the case of long-term heat insulation, a decrease in the furnace temperature cannot be avoided. If there is solution in the furnace, the tuyere position must be raised to prevent backflow of the solution to the tuyere, and setting the burner to the tuyere is not preferable for work safety. There was a problem. It is further preferable that the same heat retaining effect can be obtained with a smaller amount of fuel.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a converter heat insulation method capable of more advantageously maintaining the converter heat when the operation is interrupted, and a converter furnace cover device suitable for implementing the method.

[0010]

The above object has been attained by the present invention having the following points. (1) A method for keeping a converter warm, characterized in that the furnace opening of the converter is covered with a furnace lid when the operation of melting the copper melt using the converter is interrupted. (2) A converter characterized by 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, and covering the furnace opening of the converter with a furnace lid. How to keep warm.

(3) While the operation is continued, the furnace lid is kept obliquely above the converter, and when the operation is interrupted, the furnace lid is rotated and lowered by 60 to 120 ° to fix the furnace in a fixed position. The method for keeping a converter warm according to any one of (1) and (2), covering the mouth. (4) The furnace lid is detachably attached to the furnace port of the converter for melting copper hot water, and has a column for preventing the furnace cover from coming off from the furnace port when the converter is tilted (1) to (3). The method for keeping a converter warm according to any one of the above.

(5) A furnace lid detachably mounted on a furnace port of a converter for melting copper hot water, and a furnace cover attaching / detaching machine holding the furnace lid rotatably and vertically movable and detaching it from a fixed position of the furnace port. A converter furnace lid device comprising: (6) The furnace cover attaching / detaching machine includes a wire for suspending the furnace cover, a pulley for guiding the wire, a feeder for feeding or feeding the wire, and an arm for supporting the pulley and the feeder / extractor. The distance between the position just above the furnace opening at the fixed position and the standby position obliquely above the fixed position is 60 to 12
The converter furnace lid device according to (5), further comprising: a rotating shaft that rotates by 0 °.

(7) The converter furnace cover device according to (5) or (6), wherein the furnace cover has a column for preventing the furnace cover from coming off from the furnace port when the converter is tilted. (8) A furnace lid characterized in that it has a column that is detachably attached to the furnace port of the converter for smelting copper hot water and has a column for preventing the converter from coming off from the furnace port when the converter is tilted.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, a method is employed in which a liquid or gas fuel flame is blown into a converter from a converter tuyere when a converter operation is interrupted, and the furnace opening of the converter is covered with a furnace lid.
By this furnace lid attachment, heat dissipation from the furnace port is effectively suppressed and the furnace heat retention is enhanced, and for a short time insulation of about 1 to 15 minutes, heating using fuel is not required. The temperature inside the furnace can be prevented from lowering. Also, when heating using fuel, the inside of the converter can be kept warm with a smaller amount of liquid or gas fuel than before. In addition, when the furnace lid is applied when the converter is kept warm by a liquid or gas fuel flame, the interruption time is suitable for keeping the medium for about 5 minutes to 5 hours. In this case, it is convenient and convenient to blow the flame from the tuyere using a burner.

As the liquid fuel, kerosene, fuel oil A, etc., which have good handleability and have a high combustion efficiency even with a furnace lid, can be preferably used. Further, as the gas fuel, liquefied petroleum gas with good handling efficiency and good combustion efficiency like liquid fuel, propane, butane, a mixed gas of propane and butane,
Ammonia gas or the like can be preferably used. In addition, at least one of solid fuel, liquid fuel, and gas fuel is burned in the converter after the furnace repair, and the furnace port is covered with a furnace lid to efficiently heat and raise the refractory in the converter. You can also warm it.

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. Further, it is possible to cope with a case where the furnace lid needs to be frequently opened and closed (for example, a case where the interruption time is as short as about 5 minutes).

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 a 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 lid device 6 is operated, for example, as follows. 1) Confirm that the front movable hood 4 is retracted when the operation is interrupted (or stopped). 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) Rotate the arm 6A downward by 90 ° and lower it 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.

[0025]

EXAMPLES (Example 1) After the copper making operation in a converter with a production volume of 210 tons / lot of copper hot water, troubles in other processes forced the interruption of the operation for 3 hours. Therefore, according to the present invention,
After the copper hot water was discharged into the ladle, the kerosene 45 l / h x 2 burners (total 90 l / h) were continuously blown from the tuyere into the furnace during the operation interruption, and the heat retention by the furnace lid according to the present invention was shown in Figs.
It carried out in the mode shown in FIG. The opening size of the furnace opening of this converter was 2000 mm in the circumferential direction of the furnace and 2700 mm in the furnace length direction. Therefore, the outer dimensions of the furnace lid were adjusted so that the furnace opening could be covered with a margin. Circumferential width = 2540 mm, furnace length width = 28
The thickness was set to 00 mm, and the thickness was set to 200 mm. Yotai Casco C-14 manufactured by Yotai Co., Ltd.
0-SC30 was used. The furnace lid was provided with two columns of 75mmφ × 300mm length and two 250mm square exhaust holes. For the furnace lid attachment / detachment machine, the arm and rotating column are made of steel,
An ordinary drum winding type was used as the feeding / unloading machine.

As a result, the operation for the next batch in the sintering period could be carried out without any problem without adjusting the amount of the cooling material. In addition, as a result of keeping the heat using the furnace lid for one year, the amount of kerosene used for heat insulation in the furnace and for heat insulation of the solution such as copper water when the operation of the converter was interrupted,
Conventionally, it was able to reduce about 20% annually from about 90 m ³ / year per furnace to about 72 m ³ / year. In addition, there was no decrease in the effective furnace volume due to the residue.

[0027]

According to the present invention, when the operation of the converter is interrupted, the effect of keeping the heat of the solution or refractory in the converter increased and the operation of the converter is always stable without changing the operation conditions after the restart. Is now available. Especially for short-term repetitive heat insulation needs, the furnace lid that allows anyone to easily perform the attachment and detachment work achieves a quick response and an increase in the heat insulation power in the furnace. Various effects can be obtained in that the amount of gas fuel used can be reduced and the residue can be prevented from sticking to the bricks in the furnace.

[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 Mining & Smelting Co., Ltd. 1 Mitsui Mining & Smelting Co., Ltd. Hibiki Refinery (72) Inventor Kimihiro Shimokawa 6-1-1 Hibi, Tamano-shi, Okayama Pref. GA06 GB12 4K051 AA02 AB09 MA12 MA13

Claims (8)

[Claims] 1. A method for keeping a converter warm, wherein a furnace opening of a converter is covered with a furnace lid when an operation of melting copper hot water using the converter is interrupted. 2. A liquid or gas fuel flame is blown into the converter from the tuyeres when the operation of melting the copper melt using the converter is interrupted, and the furnace opening of the converter is covered with a furnace lid. Converter insulation method. 3. While the converter operation is continuing, the furnace lid is kept at a position obliquely above the converter, and when the operation is interrupted, the furnace lid is rotated and lowered by 60 to 120 ° to be in a fixed position. 3. The method according to claim 1, wherein the furnace port is covered. 4. The furnace lid according to claim 1, wherein said furnace lid is detachably mounted on a furnace port of a converter for smelting copper metal, and has a column for preventing the furnace cover from coming off from the furnace port when the converter is tilted. The method for keeping a converter warm according to any one of the above. 5. A furnace cover detachably covering a furnace opening of a converter for melting copper hot water, and a furnace cover attaching / detaching machine for holding the furnace cover rotatably and vertically movable and attaching and detaching the furnace cover to a fixed position furnace opening. A converter furnace lid device comprising: 6. The furnace lid attaching / detaching machine supports a wire for suspending the furnace lid, a pulley for guiding the wire, a feeding / unloading machine for feeding or unloading the wire, and the pulley and the feeding / unloading machine. 6. The converter furnace lid device according to claim 5, further comprising an arm, and a rotary support shaft for supporting the arm and rotating the arm from a position immediately above a fixed position of the furnace port to a standby position obliquely above the furnace port by 60 to 120 degrees. 7. The converter furnace cover device according to claim 5, wherein the furnace cover has a column for preventing the furnace cover from coming off from the furnace port when the converter is tilted. 8. A furnace lid, which is detachably mounted on a furnace opening of a converter for melting copper hot water and has a column for preventing the converter from coming off from the furnace opening when the converter is tilted.