JPH1060450A - Production of coke for metallurgy and equipment therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for improving quality of coke deteriorated by lowering of a dry distillation temperature and shortening of the dry distillation time to equivalent or higher than the quality of coke dry-distilled at a high temperature and to provide an equipment for performing this method. SOLUTION: (1) Red-heat coke discharged from a coke oven is charged into a pre-chamber part 12 of a cooling tower 11 in a coke dry extinguisher and a combustion gas and an oxygen-containing gas are introduced into the pre- chamber part and burnt to reheat the red heat coke at a temperature higher than a dry distillation temperature. A quality improving effect is especially remarkable by using a hydrocarbon-based fuel (e.g. tar) as the combustion gas. (2) This coke re-heating and dry extinguishing equipment has an introducing tube of the combustion gas and oxygen-containing gas and a kindling generator (e.g. a burner 14) to ignite their mixed gas at an upper part of the pre-chamber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a metallurgical coke by carbonizing coal in a coke oven, and an apparatus therefor.

[0002]

2. Description of the Related Art Generally, coke for metallurgy, for example, coke for blast furnace, has a high strength so as to ensure air permeability in a blast furnace, and has a high heat resistance in order to suppress coke compaction and powdering. It is required to have a low reactivity with carbon dioxide gas (CO ₂ ) in the temperature range (high temperature range of 1000 to 1200 ° C.). In addition, it is necessary that the manufacturing cost be as low as possible.

[0003] Among them, in order to reduce the production cost, it is effective to use inexpensive low-grade coking coal, and to reduce the amount of carbonization heat by lowering the carbonization temperature and shortening the carbonization time. but none of these methods reduce the strength of coke and a small coke to increase the reactivity with CO ₂ in the hot agglomeration, there is a drawback to promote the powdering. For this reason, various technical improvements have been made with respect to the blending and pretreatment of the charged coal, the improvement or uniformity of the bulk density in the kiln, and the combustion method, etc., and the coke quality has been improved. These methods are all improvement methods before or during carbonization.

[0004] On the other hand, coke dry fire extinguishing equipment is used in many coke factories. This is an energy-saving facility that cools red hot coke discharged from a coke oven and recovers its sensible heat. However, the quality is apparently improved due to the soaking / gradual cooling effect in the cooling tower of the dry fire extinguishing equipment and the stabilizing effect due to powdering and falling off of the fragile portion of coke at the time of unloading. Therefore,
It can be said that dry fire extinguishing of coke is a kind of quality improvement method after carbonization.

[0005] Several methods have been proposed for utilizing the dry fire extinguishing system to positively improve the quality of coke that has been reduced due to reduced calorific heat. That is, this method is a method in which red-hot coke discharged from a coke oven is charged into a cooling tower of a dry-type fire extinguishing facility and reheated in a pre-chamber section.

For example, there is a method of improving the quality by blowing hydrocarbons (for example, tar) into a pre-chamber portion of a cooling tower of a coke dry fire extinguishing system (see Japanese Patent Application Laid-Open No. 63-8480). is there. In this method,
As hydrocarbons such as tar decompose in gas phase on red hot coke, the generated pyrolytic carbon adheres to the surface of red hot coke, and further enters pores and cracks, filling that part with pyrolytic carbon. It will be in the state that was done. For this reason,
The wear strength and crush strength are improved. Furthermore, the pyrolytic carbon that coats the coke surface is a graphitizable optically higher-order anisotropic carbon, such as CO ₂ or water (H ₂
O) and the like, and the reaction speed with CO ₂ and H ₂ O in the blast furnace can be suppressed, and coke agglomeration and powdering can be suppressed.

[0007] However, in this method, although the quality of coke is certainly improved, the entire amount of the added tar does not react, and the unreacted tar is mixed into the circulating gas for heat exchange and introduced into the boiler section. It cools down and condenses, and adheres to piping and the like. Therefore, various operation troubles are induced.

[0008] A method of improving the quality of coke by blowing air into a pre-chamber portion of a cooling tower of a coke dry fire extinguishing system has also been proposed (Japanese Patent Publication No. 7-33511). In this method, a gas generated from red hot coke is burned by oxygen in the air, and the reaction heat increases the temperature of red hot coke to improve wear strength and crush strength.

Although this method is very simple and attractive in terms of equipment, it has a problem that the contact between air and gas generated from red hot coke is not always sufficient. That is, in the coke dry fire extinguishing system, the gas is finally led to the flue, so that the air and the gas generated from the red-hot coke basically flow downward in the pre-chamber.
In such a flow, the blown air first contacts the glowing coke on the upper surface, and the oxygen in the air reacts with the carbon in the coke and only the coke in the area where the air is blown is locally localized. This causes local heating.

Furthermore, hot air generated by the combustion of the circulating gas of the dry fire extinguishing system is blown into the prechamber portion of the cooling tower of the coke dry fire extinguishing system to raise the temperature of the red hot coke, thereby improving the coke quality such as abrasion strength and crushing strength. A method for improving the performance is known (Japanese Patent Application Laid-Open No. Hei 7-126462).

In this method, hot air is blown and the red hot coke is heated by the heat, so that a wider range of red hot coke can be heated more uniformly, and since the hot air has low reactivity, it can be prevented from disappearing due to combustion of product coke. Preferred. However, since the hot-air generator becomes large-scale in terms of equipment, a large amount of equipment cost is required, and heat loss during blowing hot air from the generator to the blow port is large, which is economically disadvantageous. Furthermore, since the input of the red hot coke to the coke dry fire extinguishing equipment is intermittent, there arises a problem that the intermittent operation must be performed even for the hot air generator in which the intermittent operation is difficult.

[0012]

As described above, in order to reduce the production cost of metallurgical coke such as coke for blast furnace, the amount of carbonization heat is reduced (that is, the carbonization temperature is reduced or the carbonization time is shortened). Various methods have been attempted to improve the reduced coke quality by reheating treatment in a coke dry-type fire extinguishing facility, but all have problems.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems in the prior art, and the coke dry fire extinguishing equipment can efficiently reduce the coke quality reduced by lowering the carbonization temperature and shortening the carbonization time. It is an object of the present invention to provide a method for producing metallurgical coke, which is improved by reheating coke to recover the quality of conventional high-temperature carbonized coke to the same level as that of conventional coke, and an apparatus therefor.

[0014]

Means for Solving the Problems The present inventors have variously addressed the above problems in a method for improving the quality of a low-temperature carbonized coke produced by lowering the carbonization temperature by reheating the coke dry-type fire extinguishing equipment. investigated. As a result, a fire generating device was installed above the pre-chamber of the cooling tower of the coke dry fire extinguishing equipment, and the mixed gas of the oxygen-containing gas and the combustible gas introduced into the pre-chamber was burned using the fire generating device, and the heat was And found that the quality of the coke can be improved by reheating the red hot coke, and the present invention has been accomplished.

The gist of the present invention is as follows (1) and (2)
And (3) a coke reheating dry-type fire extinguishing system.

(1) The red-hot coke discharged from the coke oven is introduced into the pre-chamber portion of the cooling tower of the coke dry-fire extinguishing system, and then the combustible gas and the oxygen-containing gas are introduced into the pre-chamber portion and burned. A method for producing coke for metallurgy, comprising reheating the red hot coke at a temperature higher than the carbonization temperature.

(2) The combustible gas introduced into the pre-chamber section is a hydrocarbon fuel.
3. The method for producing metallurgical coke according to claim 1.

(3) Above the prechamber of the cooling tower of the coke dry-type fire extinguishing equipment, there is provided an inlet pipe for combustible gas and oxygen-containing gas, and a fire generator for igniting the mixed gas of combustible gas and oxygen-containing gas. A coke reheating dry fire extinguishing system characterized by the following.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention (the above (1) to
The invention of (3), the invention of (1) and the invention of (2) are also referred to as the method of the present invention) will be described in detail.

In the invention of the above (1), red hot coke discharged from a coke oven is introduced into a prechamber portion of a cooling tower of a coke dry fire extinguishing system, and then a combustible gas and an oxygen-containing gas are introduced into the prechamber portion. This is a method of burning and reheating the red hot coke at a temperature higher than the carbonization temperature.

The red hot coke to be charged into the pre-chamber section is a low-temperature carbonized coke which is carbonized at 700 to 900 ° C. in a coke oven. This is because the amount of carbonization heat is reduced to reduce the cost of producing coke, and the quality of the reduced coke is improved by reheating the coke in the pre-chamber of the dry fire extinguishing system.

The gas used for reheating the red hot coke is a combustible gas and an oxygen-containing gas. The red hot coke is charged into the pre-chamber and then into the same chamber.

As described above, as a method for reheating the red hot coke charged into the pre-chamber section, air is blown into the pre-chamber section to mix oxygen in the air with red hot coke (or gas generated from the red hot coke). There is a method of using reaction heat and a method of blowing hot air with low reactivity containing no oxygen or the like and using the sensible heat.
However, in the method, there is a problem that coke is locally burned and local heating occurs.In the method, a large-scale hot-air generating furnace is required, and a large heat loss occurs before the air is blown to the pre-chamber section. There is also a problem. Therefore, in the method of the present invention, a combustible gas and an oxygen-containing gas are introduced into the pre-chamber portion, the combustible gas is burned by the oxygen-containing gas, and the heat is used for reheating red hot coke.

As the combustible gas, for example, a circulating gas for cooling coke dry fire extinguishing equipment or a gas generated from a coke oven can be used. As will be described later in detail as the invention (2), a hydrocarbon fuel may be used. As the oxygen-containing gas, air, oxygen, a mixed gas of nitrogen and oxygen, or the like may be used.

In order to burn the combustible gas, for example, a fire generating device may be provided in the pre-chamber, as described later, to ignite the combustible gas.

The reheating of the red hot coke is performed at a temperature higher than the carbonization temperature. This is because no coke quality improvement effect is observed below the carbonization temperature, as shown in the examples described below.

According to the method of the present invention, the coke quality can be improved without the problem of the local combustion of the coke and the large-scale hot-air generating furnace required in the conventional method, and without a large heat loss at the time of blowing. Can be improved. Therefore, it is possible to lower the carbonization temperature and shorten the carbonization time, thereby increasing the productivity of the coke oven and reducing the production cost.

The invention of the above (2) is an invention in which the hydrocarbon fuel is used as the combustible gas in the above invention of the above (1). That is, the red-hot coke discharged from the coke oven is charged into the pre-chamber part of the cooling tower of the coke dry-fire extinguishing equipment, and then the hydrocarbon-based fuel and the oxygen-containing gas are introduced into the pre-chamber part. This is a method in which a hydrocarbon-based fuel is ignited and burned by a generator to reheat the red hot coke.

In this case, the red-hot coke is reheated, and the unburned hydrocarbons are thermally decomposed. As described above, the generated pyrolyzed carbon adheres to the surface of the red-hot coke, and further, pores and cracks are generated. , And the portion is filled with pyrolytic carbon, and the quality of coke is greatly improved.

In the method disclosed in the above-mentioned JP-A-63-8480, that is, in the method in which hydrocarbons (for example, tar) are gas-phase cracked on red-hot coke charged in a pre-chamber, coke is used. Although the quality of the tar improves, the entire amount of tar added does not react, and the unreacted tar mixed in the circulating gas (circulating gas for cooling the coke dry fire extinguishing equipment) cools, condenses, and adheres to pipes, etc. This was causing operational trouble. However, in the invention of (2), since the oxygen-containing gas is introduced at the same time, the hydrocarbon-based fuel does not enter the circulating gas without being burned.
Operational troubles of the coke dry fire extinguishing system due to residual unreacted hydrocarbons will not occur.

As the hydrocarbon-based fuel, any gas or liquid can be used as long as it can be introduced as a fuel into the pre-chamber section. Specifically, acetylene, propane, methane, and furthermore,
Tar, naphtha, light oil, heavy oil and the like can be mentioned, but tar is preferable from an economic viewpoint.

In the invention of the above (3), a flammable gas and an oxygen-containing gas introduction pipe and a mixed gas of the flammable gas and the oxygen-containing gas are ignited at the upper part of the prechamber of the cooling tower of the coke dry fire extinguishing system. Is a coke reheating dry-type fire extinguishing system having a fire type generator for the fire.

The flammable gas and oxygen-containing gas introduction pipe and the ignition device are provided at the upper part of the pre-chamber because the gas flows downward toward the flue in the pre-chamber as described above. This is because uniform heating can be achieved.

The flammable gas and oxygen-containing gas introduction pipes are
Each may be a separate tube, or may be a single inlet tube through which a mixed gas of combustible gas and oxygen-containing gas is passed. In the case of separate introduction tubes, it is assumed that the combustible gas and the oxygen-containing gas are mixed at least at the time of ignition.

As the spark type generating device, a burner, an electric spark generating device or the like can be used. It is preferable that the fire generating device is attached to a portion close to a combustible gas and an oxygen-containing gas introduction tube so that ignition is easily performed.

FIG. 1 is a diagram showing the configuration of an example of a burner used as a fire type generator and an inlet pipe for a combustible gas and an oxygen-containing gas. As shown in the figure, the burner 1 is connected to a fuel introduction pipe 2 and an air introduction pipe 3, and is provided at the tip of the nozzle of the burner 1 so as to easily ignite a mixed gas of combustible gas and oxygen-containing gas. In the vicinity, a combustible gas introduction pipe 5 and an oxygen-containing gas introduction pipe 6 are arranged. Code 4
Is a combustible gas injection port, where the combustible gas and the oxygen-containing gas are mixed and ignited at the same time, so that the combustible gas can be efficiently burned.

As described above, the combustible gas sent to the combustible gas introduction pipe 5 includes a circulating gas for cooling coke dry fire extinguishing equipment and a coke oven generated gas, such as an oxygen-containing gas sent to the oxygen-containing gas introduction pipe 6. For example, air, oxygen, a mixed gas of nitrogen and oxygen, or the like can be used. As the fuel for the burner sent to the fuel introduction pipe 2, for example, a circulating gas for cooling coke dry fire extinguishing equipment, a coke oven generated gas, propane, acetylene and the like can be used.

FIG. 2 is a diagram showing an example of the configuration of a coke reheating dry-type fire extinguishing system according to the present invention. The burner shown in FIG. ) Is the pre-chamber 1 of the cooling tower 11
2 attached to the upper part.

When this apparatus is used, the red hot coke is supplied from the red hot coke inlet 13 to the pre-chamber 1 of the cooling tower 11.
2, the mixed gas of combustible gas and oxygen-containing gas is ignited and burned by a burner 14 provided at the upper part of the pre-chamber 12, and is burned to easily reheat red hot coke. can do. In addition, since a circulating gas for cooling coke dry fire extinguishing equipment or a coke oven generated gas can be used as the combustible gas, it is preferable from an economic viewpoint.

[0040]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The method of the present invention (method (1) or (2)) using a coke dry-fire extinguishing system having the configuration shown in FIG.
Method).

Red hot coke having an average carbonization temperature of 850 ° C. was introduced into the prechamber 12 of the cooling tower 11 of the coke dry fire extinguishing system through the red hot coke charging inlet 13. The red hot coke was charged every 8 minutes. After charging the red hot coke, circulating gas or tar for cooling the coke dry fire extinguishing equipment is injected from the combustible gas injection port of the burner 14 provided at the upper part of the pre-chamber 12 for 8 minutes until the next red hot coke is input. By supplying a fixed amount of air, oxygen, or a mixed gas of nitrogen and oxygen (oxygen 60 vol%) from an oxygen-containing gas introducing pipe, the circulating gas or tar was burned, and the red hot coke temperature was raised to 950 ° C. Thereafter, the coke was cooled to 150 ° C. in the cooling tower 11, and the cold coke was discharged from the cold coke outlet 15.

Example 1 The method of the present invention was carried out by using a burner as a fire-generating device, using a combustible gas as a circulating gas for cooling coke dry fire extinguishing equipment, and using an oxygen-containing gas as air, oxygen, or a mixed gas of nitrogen and oxygen. Coke was produced by the method (1)). The specifications in the coke dry fire extinguishing system at this time are as shown in Table 1. In addition, the hot air volume in the same table is a hot air volume obtained by burning the circulating gas for cooling the coke dry fire extinguishing equipment with air.

[0043]

[Table 1]

[0044] The discharged cold coke, determine the drum strength went drum strength test (JIS K2151), was measured further CO ₂ strength after reaction (CSR).

For comparison, the same measurement was performed for coke (medium to low temperature carbonized coke) produced without lowering the carbonization temperature and then reheating after retorting, and for high temperature carbonized coke produced by the conventional method. The quality of the coke produced by the inventive method was compared. The average carbonization temperature in the conventional method was 950 ° C.

Table 2 shows the measurement results of the drum strength and the strength after the CO ₂ reaction. As is apparent from the results, the method of the present invention was able to produce coke having a quality almost equivalent to that of the high-temperature carbonized coke produced by the conventional method in both the drum strength and the post-CO ₂ reaction strength. Also, substantially the same results were obtained using any of air, oxygen, or a mixed gas of nitrogen and oxygen as the oxygen-containing gas.

The low-temperature carbonized coke discharged at an average carbonization temperature of 850 ° C. and not reheated had a low drum strength and a low post-CO ₂ reaction strength, and was clearly inferior in quality (Comparative Example 1). ).

Although not shown, a similar effect was observed when a coke oven generated gas, acetylene, or propane was used as the combustible gas. In addition, some tests were conducted using an electric spark generator as a spark type generator, but it was confirmed that ignition of a mixed gas of combustible gas and oxygen-containing gas could be performed easily as in the case of using a burner. .

[0049]

[Table 2]

Example 2 A comparison was made between the conventional method of reheating red hot coke with hot air produced by an external hot air generator and the method of the present invention (method (1)).

In the method of the present invention, a burner was used as a fire type generator, the flammable gas was a circulating gas for cooling coke dry fire extinguishing equipment, and the oxygen-containing gas was air. The specifications in the coke dry fire extinguishing system at this time are as shown in Table 1 above, and the amount of hot air required to reheat the red hot coke to 950 ° C. is 30,000 m ³ / hr. The temperature of the hot air was 1600 ° C.

On the other hand, in the method of reheating with hot air produced by an external hot air generator, a circulating gas for cooling coke dry fire extinguishing equipment is burned to produce hot air at 1600 ° C.
After charging red hot coke, it was blown into the pre-chamber for 8 minutes until the next red hot coke was charged. At this time, the temperature of the hot air is 12
The temperature drops to 00 ° C and the amount of hot air required for reheating is 75000
m ³ / hr.

Table 3 shows the measurement results of the drum strength and the strength after the CO ₂ reaction for the obtained coke. As is clear from the results, the quality of the coke was comparable, but in the method of the present invention, the required amount of hot air was less than half as compared with the method of reheating with hot air produced by an external hot air generator. . This is because there is no inevitable heat loss in the method of reheating with hot air produced by an external hot air generator (indicated as Comparative Example 2). According to the method of the present invention, it is possible to efficiently reheat red hot coke. I understand.

[0054]

[Table 3]

Example 3 Reheating of coke was carried out by changing the reheating temperature of red hot coke in a coke dry fire extinguishing facility, and the quality of the obtained coke was measured. The specifications in the coke dry fire extinguishing system at this time are as shown in Table 1 above.

Table 4 shows the measurement results. From this result, when the reheating temperature is equal to or lower than the carbonization temperature in the coke oven, no improvement in coke quality is recognized, and it is clear that the reheating temperature needs to be higher than the carbonization temperature.

[0057]

[Table 4]

[Example 4] Using a burner as a igniter, using a combustible gas as tar and an oxygen-containing gas as air, coke was produced by the method of the present invention (method (1) and method (2)). Manufactured. The specifications of the coke dry fire extinguishing system at this time are as shown in Table 5.

[0059]

[Table 5]

With respect to the discharged cold coke, the strength of the drum and the strength after the reaction with CO ₂ were measured, and the amount of tar adhering to the filter attached to the inlet side of the boiler connected to the coke dry fire extinguishing equipment was measured. The presence of unreacted tar was examined.

For comparison, the same applies to a medium-to-low-temperature carbonized coke produced without reheating (Comparative Example 3) and a coke produced by blowing only tar without introducing an oxygen-containing gas (Comparative Example 4). Measurements were made and compared with the quality of the coke produced by the method of the present invention.

Table 6 shows the drum strength, the strength after the CO ₂ reaction,
And the measurement results of the residual tar amount are shown. In Table 6,
Example 3 of the present invention is a case where the method (1) is applied,
Example 4 of the present invention is a case where the method (2) is applied.

As is evident from the results, the present invention in which the tar was burned with air using a burner, and the low-temperature carbonized coke that had been carbonized at 850 ° C. was reheated to 950 ° C., and simultaneously the pyrolytic carbon was deposited. In Example 4, coke having a quality higher than that of the high-temperature carbonized coke produced by the conventional method in both the drum strength and the post-CO ₂ reaction strength was able to be produced. In addition, no unreacted tar remained, confirming that the coke dry-fire extinguishing system can be operated without causing operational trouble. In addition, in Example 3 of the present invention, as shown in Examples 1 to 3, coke having almost the same quality as high-temperature carbonized coke could be produced.

[0064]

[Table 6]

[0065]

According to the method of the present invention, it is possible to efficiently reheat red-hot coke in the pre-chamber portion of the coke dry-fire extinguishing system, and to improve the quality of medium- to low-temperature carbonized coke to the quality of high-temperature carbonized coke. It can be as good or better.

[0066] This makes it possible to lower the carbonization temperature and shorten the carbonization time even in the production of metallurgical coke, such as for a blast furnace, which requires high quality, so that the productivity of the coke oven is improved. Manufacturing costs can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an example of a burner used as a fire generating device and an introduction pipe for a combustible gas and an oxygen-containing gas.

FIG. 2 is a diagram showing a configuration of an example of a coke reheating dry-type fire extinguishing facility of the present invention.

[Explanation of symbols]

 1: Burner 2: Fuel introduction pipe 3: Air introduction pipe 4: Combustible gas injection port 5: Combustible gas introduction pipe 6: Air introduction pipe 11: Cooling tower 12: Pre-chamber 13: Red hot coke inlet 14: Burner 15: Cold Coke cutout

Claims (3)

[Claims] The present invention comprises the steps of: charging red-hot coke discharged from a coke oven into a pre-chamber portion of a cooling tower of a coke dry-fire extinguishing system; introducing a combustible gas and an oxygen-containing gas into the pre-chamber portion; A method for producing metallurgical coke, comprising reheating red hot coke at a temperature higher than the carbonization temperature. 2. The method for producing coke for metallurgy according to claim 1, wherein the combustible gas introduced into the pre-chamber portion is a hydrocarbon-based fuel. 3. A combustible gas and an oxygen-containing gas introduction pipe, and a fire generating device for igniting a mixed gas of the combustible gas and the oxygen-containing gas, above the prechamber of the cooling tower of the coke dry-type fire extinguishing equipment. Coke reheating dry fire extinguishing equipment characterized by the following.