JPH0718260A - Production of metallurgical coke - Google Patents

Abstract

PURPOSE:To improve the abrasion and compression strengths of coke and minimize the dusting during the feeding of coal by cooling a red-hot coke in a dry-quenching apparatus with a hydrocarbon gas. CONSTITUTION:A hydrocarbon gas and/or a gas contg. a hydrocarbon gas is supplied via a circulation fan 2 from a gas entry port 1a into a dry-quenching apparatus 1 to cool a red-hot coke 3 fed through a feeding port 1b. The cooled coke is discharged continuously through a discharge port 1c. The gas used for cooling is lead through a duct 1d to the outside of the quenching apparatus 1, is freed from dust at a dust separator 4, and subjected to heat recovery at a steam boiler 5. Then, a part of the gas is expelled to the outside of the system and the rest is recirculated as the cooling gas through a cyclone 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing metallurgical coke, and more particularly to a method for producing metallurgical coke which has a high cold strength and a low reactivity with CO ₂ in the hot state.

[0002]

2. Description of the Related Art In general, metallurgical coke has a high strength in order to ensure air permeability in a blast furnace, and a hot (100
A substance having low reactivity with CO ₂ in a high temperature range of 0 to 1200 ° C.) is required. Furthermore, it is required that the manufacturing cost be as low as possible only for those used in large quantities.

Of these, in order to reduce the manufacturing cost, it is effective to use inexpensive low-grade raw material coal or reduce the amount of dry distillation heat, but all of these methods reduce the strength of coke. In addition, there is a drawback in that the reactivity with CO ₂ during hot is enhanced to promote the agglomeration and pulverization of coke. For this reason, various technical improvements such as a method of blending the charged coal, a pretreatment method, a method for improving and uniforming the bulk density of the coal in the kiln, and a method for combustion have been made. However, all of these methods are improvement methods before or during carbonization and not for coke after carbonization.

By the way, in recent years, coke dry fire extinguishing equipment has been adopted in many coke manufacturing plants. This is an energy-saving facility that cools the red hot coke and at the same time recovers its sensible heat. However, it has a soaking and slow cooling effect in the cooling tower, and a stabilizing effect due to pulverization of the fragile part of the coke when unloading the load. Apparently improves the quality. Therefore, it can be said that this is a kind of quality improvement method after carbonization.

On the other hand, some methods have been proposed to positively improve the quality of coke after carbonization. For example, a method of spraying heavy oil on red hot coke produced by carbonization during the cooling process (Japanese Patent Publication No. 54-15).
No. 6006), a method of blowing hydrocarbons into the pre-chamber part of the cooling tower of the dry fire extinguishing equipment to improve the quality (Japanese Patent Laid-Open No. 63-8480).

In these methods, heavy oil and hydrocarbons are vapor-decomposed on the red hot coke, and the produced pyrolytic carbon adheres to the surface of the red hot coke and penetrates into pores and cracks. Since it is filled, abrasion strength and crushing strength are improved.

Further, the pyrolytic carbon formed as a coating is a graphitizable, optically higher-order anisotropic carbon, and has a very low reaction rate with CO ₂ , H ₂ O, etc. Agglomeration and pulverization of coke due to the reaction with ₂ and H ₂ O can be suppressed.

[0008]

However, when the liquid or solid hydrocarbons are blown into the red hot coke in this way, the hydrocarbons do not coke on the coke to produce pyrolytic carbon, and the quality of the coke is not improved. May not be improved. Further, in the pre-chamber part, soot is partially generated from the hydrocarbon compound, and there is a drawback that a large amount of dust is generated when charging the coke.

The present invention has been made in view of the above problems, and when the hydrocarbons are blown in the dry fire extinguishing equipment to improve the quality of coke, the blown hydrocarbons are coking. It is an object of the present invention to provide a method for producing metallurgical coke, which can generate pyrolytic carbon without performing the above and can suppress dust generation during coke charging as much as possible.

[0010]

In order to achieve the above-mentioned object, the method for producing a metallurgical coke according to the present invention uses a hydrocarbon gas and / or a gas containing a hydrocarbon gas in a dry digestion facility. That is to cool the red hot coke.

[0011]

[Function] Hydrocarbons undergo vapor phase pyrolysis on red hot coke. Then, the generated pyrolytic carbon adheres to the surface of the red hot coke and penetrates and fills the pores and cracks on the surface of the coke, so that the wear strength and the crush strength are improved. Furthermore, pyrolytic carbon produced coating is optically higher anisotropy carbon graphitizable, rate of reaction with CO ₂ and H ₂ O or the like is extremely small, these CO ₂ and H in the blast furnace
It is possible to suppress coke lumping and pulverization due to the reaction with ₂ O.

Pyrolytic carbon is produced by the reaction of gas phase hydrocarbons with red hot coke, but when liquid or solid phase hydrocarbons contact red hot coke, the hydrocarbons coke, No pyrolytic carbon is produced. Therefore, when injecting liquid or solid hydrocarbons, it is necessary that the hydrocarbons first evaporate into a gas phase. Evaporation occurs even after reaching the red hot coke, but in order to evaporate the total amount of blowing, it is necessary to devise a blowing method.

In order to further enhance the quality improvement effect, it is necessary to increase the amount of hydrocarbons blown in. However, in the case of liquid or solid hydrocarbons, if the amount of injections is too large, coking is likely to occur without vaporization. .

On the other hand, if gaseous hydrocarbons are blown in, there is no need to evaporate them, and since they are already in the vapor phase, they can be blown in easily, and there is no fear of caulking and the amount of blown is large. can do.

In addition to the problem of coking, hydrocarbons become heavier in the gas phase at the same time as pyrolysis carbon is produced, producing soot. Therefore, when hydrocarbons are blown into the pre-chamber part, soot is generated at the same time when the pre-chamber is blown, and the amount of dust at the time of charging the coke increases.

The generation of soot increases as the vapor phase temperature rises, but when hydrocarbons are blown into the prechamber part, the flow of the blown hydrocarbon and the red hot coke becomes the same direction, so-called cocurrent flow. The phase temperature is as high as that of red hot coke, and soot is easily generated. On the other hand, when the hydrocarbon gas is used as the cooling gas or the hydrocarbon gas is mixed in a part of the cooling gas, the cooling gas is in the opposite direction of the coke, so-called alternating current, and gradually contacts the coke having a high temperature. Since it flows, the temperature is lower than that of the red hot coke even in the upper part of the cooling unit, so that soot generation can be suppressed. Further, since the cooling gas does not flow into the pre-chamber part, it is possible to suppress dust during coke charging.

The production of pyrolytic carbon on coke is
The higher the coke temperature is, the faster it is, but the red hot coke temperature is the same in the pre-chamber part and the upper part of the cooling part, and the generation of pyrolytic carbon is suppressed even when a part or all of the cooling gas is blown in as a hydrocarbon gas. There is no need to be.

Further, as a matter of course, when the hydrocarbons are blown into the pre-chamber section, a blow-in facility is required in addition to the coke cooling facility, but the hydrocarbon gas is used as the cooling gas or a part of the cooling gas. In case of blowing,
Since it also serves as cooling, coke quality can be improved with simple equipment. Here, as the hydrocarbon gas, methane, ethane, ethylene, propane, propylene, butane, butene and the like can be used, and a gas containing these hydrocarbon gases, for example, coke oven gas (CO: 5 to 10%, CH
_{4: 25~30%, H 2:} 50~60%, C n H m: 2~
_{4%, CO 2: 1~5%} ), normal commercial propane gas, natural gas _{(CH 4: 80~90%, C} m H n: 2~5%, CO
_{2: 2~4%, N 2:} 2~5%) or the like can also be used in the present invention.

The optimum amount of the hydrocarbon gas blown is determined in accordance with the amount of red hot coke to be treated, and the same applies when the hydrocarbon gas is blown as a part of the cooling gas. is there. The mixing ratio is preferably as high as possible from the viewpoint of adhering a large amount of pyrolytic carbon, but if the amount of hydrocarbons is large, soot is likely to occur,
As the mixing ratio, the hydrocarbon content is converted into methane to be 1 to
10% and 3-40% for coke oven gas are desirable.

[0020]

EXAMPLES Next, the results of the experiments carried out to confirm the effects of the present invention will be described. FIG. 1 is a configuration diagram showing an example of a dry fire extinguishing facility for carrying out the method of the present invention. In FIG. 1, reference numeral 1 denotes a dry fire extinguishing facility having a processing capacity of 100 T / H, which is a circulation fan 2. Cooling gas is supplied from the blower port 1a into the dry fire extinguishing equipment 1 to cool the red hot coke 3 charged from the charging port 1b. Then, the cooled red hot coke 3 is continuously cut out from the outlet 1c.

The cooling gas after cooling is guided to the outside of the dry fire extinguishing equipment 1 through the flue 1d, dust is removed by the dust separator 4, heat is recovered by the steam boiler 5, and a part of the gas is treated. It is discharged to the outside of the rear system and the rest is reused as a cooling gas via the cyclone 6. The gas released outside the system can be used as a low-calorie gas.

The present invention relates to the dry fire extinguishing equipment 1 as described above.
Is used to cool the red hot coke using a hydrocarbon gas or a gas containing a hydrocarbon gas.
As a first embodiment, a coke oven gas is used as a hydrocarbon gas and is blown into the pre-chamber portion 1f through the gas blowing port 1e, and as a second embodiment, the coke oven gas is not blown into the pre-chamber portion 1f and the coke oven gas is cooled as a cooling gas. The result of the case of supplying a part (25% of the cooling gas) to the dry fire extinguishing equipment 1 by the circulation fan 2 will be described. In addition, as a comparison, the result when the pre-chamber part 1f is not blown and the cooling gas is an inert gas (nitrogen) is also shown.

In the present invention, since the gas after the heat recovery by the steam boiler 5 is not circulated and used, the amount discharged outside the system after the gas treatment is large. Further, in both cases of Examples 1 and 2, the released gas had more calories than the case where the hydrocarbon gas was not blown, and it could be used as a medium calorie gas.

The quality of the coke produced for the above-mentioned three examples, Examples 1 and 2 and Comparative Example, was measured. The results are shown in Table 1 below. The coke strength is measured according to JIS K 2151.
The hot reactivity with CO ₂ was determined by measuring the coke after reacting 200 g of coke having a particle size of 19 to 21 mm with CO ₂ at 1100 ° C. and 5 Nl / min for 2 hours. The weight reduction was measured as a reaction amount, and after the reaction, the coke after the reaction was rotated at 20 rpm for 30 minutes using an I-type drum, the weight ratio of the coke remaining on the sieve without passing through a 10 mm sieve was measured. It was defined as the strength after the reaction. Regarding the quality of coke, the higher the strength and the strength after reaction, the better, and the smaller the reaction amount, the better.

[0025]

[Table 1]

As is apparent from Table 1 above, in Examples 1 and 2 in which coke oven gas was blown into the Comparative Example, the coke strength, the hot reaction amount, and the strength after hot reaction were higher than those of the Comparative Example. did. Further, in Examples 1 and 2, coking was not observed even when the coke surface was observed. When liquid tar in an amount equivalent to that of Examples 1 and 2 was blown in terms of carbon, after the coking of the tar was observed on the coke, in this example, the gaseous hydrocarbon was blown to cause coking. It is clear that the above can be avoided.

When comparing Example 1 and Example 2, there was no difference in quality, but in Example 1 the amount of dust increased due to the injection of hydrocarbons, whereas in Example 2, the coke load was increased. The dust at the time of entry was the same as when the coke oven gas was not blown in. Further, in the second embodiment, the blowing facility for the pre-chamber part 1f is unnecessary.

In this embodiment, the hydrocarbon gas or the gas containing the hydrocarbon gas is used to cool the red hot coke, but both the hydrocarbon gas and the gas containing the hydrocarbon gas are used. It goes without saying that the red hot coke may be used for cooling.

[0029]

As described above, according to the method of the present invention, it is possible to easily improve the quality of coke due to hydrocarbon gas, and dust is generated when charging red hot coke when using hydrocarbon gas. The amount can be kept small.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an example of dry fire extinguishing equipment for carrying out the method of the present invention.

[Explanation of symbols]

 1 Dry fire extinguishing equipment 1a Blower 1e Gas inlet 1f Prechamber 3 Red hot coke

Claims (1)

[Claims] 1. A method for producing metallurgical coke, which comprises cooling red hot coke in a dry digestion facility using a hydrocarbon gas and / or a gas containing a hydrocarbon gas.