JPH09194845A - Production of metallurgical coke - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize the normal operation of coke dry quenching equipment and greatly improve the quality of coke by alternately blowing a hydrocarbon fuel and an oxygen-containing gas into a prechamber of coke dry quenching equipment after charging red-hot coke into the prechamber. SOLUTION: In this process for producing a metallurgical coke by charging red-hot coke into a prechamber 2 of coke dry quenching equipment and then blowing a hydrocarbon fuel into the prechamber 2 to effect thermal decomposition, a hydrocarbon fuel 4 and an oxygen-containing gas 5 are alternately blown into the prechamber 2. It is desirable to use coke carbonized at a low to medium temperature, i.e., 700-900 deg.C, in a coke oven as the red-hot coke to be charged into the prechamber. Examples of the hydrocarbon fuel used include a coke oven gas, a natural gas, a heavy oil and a coal tar. A gas mixture comprising air or oxygen and an inert gas can be used as the oxygen-containing gas.

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 for extinguishing red hot coke using a coke dry extinguishing system, which has high cold strength and hot C
The present invention relates to a method for producing a metallurgical coke having a low reactivity with O ₂ .

[0002]

2. Description of the Related Art Generally, as a metallurgical coke, in terms of quality, it has high strength in order to ensure air permeability in the blast furnace,
Moreover, in order to suppress the lumping and pulverization of coke, 10
In the high temperature range of 00 to 1200 ° C., a low reactivity with CO ₂ and a low hot reactivity is required, and economically, an inexpensive coke with a reduced production cost is required.

In order to reduce the cost for producing the above coke, it is effective to use an inexpensive low-grade coal such as non-fine coking coal as the raw material coal to reduce the raw material unit price and the dry distillation heat amount. However, all of these methods have the drawbacks that the coke strength is lowered and the reactivity with CO _{2 during} hot is increased to promote the agglomeration and pulverization of the coke. As measures against this, raw coal blend pretreatment such as selective crushing, preheating (dry) coal charging, forming coal blending, improving or uniformizing bulk density in kiln such as oiling, and changing heating pattern Although various technical improvements have been carried out regarding the combustion switching method and the like, all of these are coke quality improving methods before or during carbonization, not coke quality improving methods after carbonization.

In recent years, coke dry fire extinguishing equipment has been adopted in many coke manufacturing plants mainly for the purpose of recovering a huge amount of sensible heat possessed by red hot coke. This coke dry fire extinguishing equipment is an energy-saving equipment that cools red hot coke and at the same time recovers its sensible heat.However, soaking in the cooling tower, gradual cooling effect, and fragile drop of coke when unloading Due to the stabilizing effect of, the quality of coke apparently improves. Therefore, it can be said that the dry coke extinguishing method is a kind of coke 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 blowing a hydrocarbon compound into a pre-chamber of a coke dry-type fire extinguisher to thermally decompose the hydrocarbon compound (Japanese Patent Laid-Open No. Sho 6-62)
3-8480), the coke oven flue temperature is set to 11
Set in the range of 50 to 1350 ℃, when the coke temperature in the center of the carbonization chamber reaches the range of at least 700 to 900 ℃, remove the kiln, load it into the coke dry fire extinguishing equipment, and load the coke. Immediately after that, air is introduced into the pre-chamber of the coke dry-type fire extinguisher, and the gas mainly generated from the coke is burned in the pre-chamber to heat the coke to a temperature of at least 900 ° or more and calcinate it ( JP-A-2-194087) has been proposed.

[0006]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the method disclosed in Japanese Patent Publication No. 80, the hydrocarbon compound is vapor-decomposed on the red hot coke, and the generated pyrolytic carbon adheres to the surface of the red hot coke and penetrates and fills the pores and cracks. Crush strength is improved. Furthermore, pyrolytic carbon coating the coke surface is optically higher different methods of carbon graphitizable, rate of reaction with CO ₂ and H ₂ O or the like is extremely small, Ya CO ₂ in the blast furnace It is possible to suppress the lumping and pulverization of coke due to the reaction with H ₂ O and the like. However, according to the method disclosed in Japanese Unexamined Patent Publication No. 63-8480, the charging of the red hot coke into the prechamber is usually intermittent charging, and the bed height per kiln is 8
Since the layer height is 0 to 100 cm, the yield is about 50% for adhering the pyrolytic carbon to the surface of the red hot coke in the layer height of 80 to 100 cm. Reacted hydrocarbons remain and are mixed in the circulating inert gas to adhere to the surface of the heat transfer tube of the heat recovery boiler to reduce the heat recovery efficiency.In addition, a bag filter is used as a dust remover for the circulating inert gas. In this case, there is a drawback that it causes clogging and increases the pressure loss of the gas circulation system, making normal operation of the coke dry fire extinguishing equipment impossible.

Further, the method disclosed in Japanese Patent Laid-Open No. 2-194087 can reduce the amount of dry distillation heat and has no major problem in the operation of the coke dry-type fire extinguishing equipment, but the obtained coke temperature is higher than the normal dry distillation temperature. No, there is an upper limit on the quality of coke.

The object of the present invention is to enable normal operation of the coke dry fire extinguishing equipment by burning and removing unreacted hydrocarbon fuel blown into the pre-chamber of the coke dry fire extinguishing equipment. An object of the present invention is to provide a method for producing metallurgical coke, which can significantly improve quality.

[0009]

The present invention relates to a prechamber in which red hot coke of a coke dry-type fire extinguisher is charged, and a hydrocarbon-based fuel for pyrolyzing carbon in a gas phase to produce an oxygen-containing gas. Will be blown in alternatingly. As described above, by alternately blowing the hydrocarbon fuel and the oxygen-containing gas that generate pyrolytic carbon by vapor-phase pyrolysis, the pyrolytic carbon adheres to the surface of the red hot coke in the pre-chamber, and unreacted. The hydrocarbon fuel is combusted by the blowing of the oxygen-containing gas to raise the temperature of the red hot coke, and the coke quality can be greatly improved.

Further, in the present invention, as the red hot coke to be charged into the pre-chamber of the coke dry fire extinguishing equipment, the medium- and low-temperature dry-distilled coke which has been dry-distilled at 700 to 900 ° C. in the coke oven is used to generate heat in the pre-chamber. While the decomposed carbon adheres to the surface of the red hot coke,
Unreacted hydrocarbon fuel burns due to the blowing of oxygen-containing gas, the red hot coke temperature rises to the normal high temperature carbonization temperature, and coke quality can be greatly improved.
Moreover, it is possible to reduce the cost of coke production by reducing the amount of dry distillation heat in the coke oven and to increase the productivity by shortening the dry distillation time.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION According to the present invention, a hydrocarbon fuel injection nozzle and an oxygen-containing gas injection nozzle are provided in the upper part of a prechamber of a coke dry fire extinguishing facility, and a prechamber charged with red hot coke is carbonized. Injecting hydrocarbon fuel from a hydrogen fuel injection nozzle,
The blowing of the oxygen-containing gas from the oxygen-containing gas blowing nozzle is alternately repeated. When hydrocarbon fuel is blown into the upper part of the red hot coke in the pre-chamber,
Since the temperature in the pre-chamber is high at 700 to 900 ° C, hydrocarbon-based fuel undergoes gas phase pyrolysis on red hot coke,
The generated pyrolytic carbon adheres to the surface of the red hot coke,
The coke quality is improved by invading and filling the pores and cracks on the surface of the coke.

However, when the hydrocarbon-based fuel is blown in for a long time, unreacted hydrocarbon-based fuel remains and is mixed in the circulating inert gas, and adheres to the surface of the heat transfer tube of the heat recovery boiler to improve the heat recovery efficiency. In addition, when a bag filter is used as a dust remover for circulating inert gas, it causes clogging and increases the pressure loss of the gas circulation system, making it impossible to operate the coke dry fire extinguishing equipment normally. Become. Therefore, there is an optimum time for blowing the hydrocarbon-based fuel, and the shorter the time is, the more preferable. For example, the time is preferably within 1 minute.

The oxygen-containing gas is blown in after the blowing of the hydrocarbon fuel is completed. Oxygen in the blown oxygen-containing gas reacts with the gas generated from the unreacted hydrocarbon fuel and the red hot coke, and the unreacted hydrocarbon fuel is burned and removed as CO, CO ₂ , and H ₂ O. . Furthermore, the temperature of the red hot coke in the pre-chamber rises due to the combustion heat of the unreacted hydrocarbon fuel and the combustion heat of the gas generated from the red hot coke, and the coke quality rises. The blowing time of the oxygen-containing gas is set in relation to the blowing time of the hydrocarbon-based fuel, but the shorter the time is, the better, for example, within 1 minute.

In the present invention, by alternately repeating the above-mentioned blowing of the hydrocarbon fuel and the blowing of the oxygen-containing gas, the adhesion of pyrolytic carbon to the surface of the red hot coke and the unreacted hydrocarbon fuel Burning removal,
Further, the temperature of the red hot coke increases due to the combustion heat of the gas generated from the unreacted hydrocarbon fuel and the red hot coke, and the quality of the coke can be greatly improved.

In the present invention, the hydrocarbon fuel blown into the pre-chamber is coke oven gas, methane,
Hydrocarbon gas such as propane and natural gas, saturated and unsaturated hydrocarbons such as heptane, hexane, benzene and toluene, petroleum fractionated oil such as naphtha, light oil and heavy oil and its residue, and crude light oil, coal tar and its One or a mixture of fractionated oil and coal liquefied oil can be used. Further, as the oxygen-containing gas blown into the pre-chamber in the present invention, air or a mixed gas of oxygen and an inert gas can be used.

[0016]

【Example】

Example 1 As shown in FIG. 1, in a pre-chamber 2 of a coke dry-type fire extinguisher system including a cooling chamber 1 and a pre-chamber 2, 12 Ton of red hot coke having a kiln discharge temperature of 800 ° C. was charged from a coke charging port 3 every 8 minutes. . After charging the red hot coke, coal tar was blown at 100 kg / min for 10 seconds from the blowing nozzle 4 in the upper part of the prechamber 2. After the coal tar was blown, air was blown through the blow nozzle 5 at the upper part of the prechamber ² at 470 Nm ³ / min for 10 seconds. Thereafter, blowing of coal tar and air was repeated as described above for 8 minutes until the next charging of red hot coke. In addition, the circulating inert gas is blown at 2000 Nm ³ / min from the circulating inert gas blowing port 6 in the lower part of the cooling chamber 1 to exchange heat with the coke for cooling, and the circulating inert gas heated by exchanging heat with the coke is After introducing from the small flue 7 provided around the boundary between the cooling chamber 1 and the pre-chamber 2 into the waste heat boiler via the circular flue 8, the flue 9, and a primary dust remover (not shown), heat is recovered, After removing dust with a secondary dust remover consisting of a bag filter, it was blown from the blowing nozzle 5 through a blower. The coke cooled to 200 ° C. by exchanging heat with the circulating inert gas in the cooling chamber 1 was sequentially cut out from the coke cutting port 10 at the lower end of the cooling chamber 1.

For comparison, a conventional example in which coal tar and air are not blown into the pre-chamber 2, a comparative example 1 in which only coal tar is blown into the pre-chamber 2, and a comparative example 2 in which only air is blown into the pre-chamber 2. In the case as well, the red hot coke was cooled in the same manner. Coke was sampled from each of the obtained cooling cokes, and JIS K
The crushing strength (drum strength) prescribed in 2151 was measured on the 15 mm sieve index after 150 rotations and the strength after CO ₂ reaction. In addition, the amount of unreacted coal tar was calculated.
Table 1 shows the results. The amount of unreacted coal tar is calculated by measuring the amount of coal tar in the circulating inert gas in the flue 9 and calculating the measurement result.

[0018]

[Table 1]

As shown in Table 1, in the case of the conventional example in which neither coal tar nor air was blown into the prechamber ₂ , the rupture strength was 82.4 and the strength after CO ₂ reaction was 54.0. In the case of Comparative Example 1 in which only coal tar was blown into the pre-chamber 2, the rupture strength = 84.2 and the strength after CO ₂ reaction = 60.0, and the coke quality is improved, but unreacted coal tar Remained at 300 kg / Hr, and the test was stopped when the pressure loss due to the clogging of the bag filter began to increase. In the case of Comparative Example 2 in which only air was blown into the pre-chamber 2, the rupture strength = 83.
4. The strength after CO ₂ reaction was 59.2. On the other hand, in the case of the present invention example in which coal tar and air were blown into the pre-chamber 2 alternately, the rupture strength = 85.5 and the strength after CO ₂ reaction = 65.0, and the coke quality was dramatically improved. ing. Moreover, unreacted coal tar did not remain, and normal operation of the coke dry fire extinguishing equipment was possible.

Example 2 As a hydrocarbon fuel blown into the pre-chamber, a petroleum heavy oil or coal liquefied heavy oil shown in Table 2 was used in place of the coal tar of Example 1, and the same test as in Example was conducted. Carried out. The results are shown in Tables 3 and 4.

[0021]

[Table 2]

[0022]

[Table 3]

[0023]

[Table 4]

As shown in Table 3 and Table 4, even when the petroleum heavy oil or coal liquefied heavy oil is used in place of the coal tar of Example 1, the petroleum heavy oil or coal is used in the prechamber 2. In the case of the conventional example in which liquefied heavy oil and air were not blown, the rupture strength was 82.4 and the strength after CO ₂ reaction was 54.0. In the case of Comparative Example 3 or 5 in which only the petroleum heavy oil or the coal liquefied heavy oil was blown into the prechamber 2, the rupture strength = 83.7 or 83.8, CO
₂ Strength after reaction = 59.3 or 59.4, the coke quality is improved, but unreacted coal tar is 200
The test was stopped when the residual amount of kg / Hr or 300 kg / Hr and the pressure loss due to the clogging of the bag filter started to increase. In the case of Comparative Example 4 or 6 in which only air was blown into the pre-chamber 2, the rupture strength = 83.
4. The strength after CO ₂ reaction was 59.2. On the other hand, in the case of Inventive Example 2 or 3 in which petroleum heavy oil or coal liquefied heavy oil and air were blown into the pre-chamber 2 alternately, rupture strength = 85.0 or 85.2, after CO ₂ reaction Strength =
It is 63.8 or 63.9, and the coke quality is dramatically improved. Moreover, unreacted petroleum heavy oil or unreacted coal liquefied heavy oil did not remain, and the normal operation of the coke dry fire extinguishing equipment was possible.

[0025]

INDUSTRIAL APPLICABILITY The present invention alternately blows a hydrocarbon-based fuel with an oxygen-containing gas into a pre-chamber of a coke dry-type fire extinguisher in which red-hot coke is charged, so that the coke is produced by blowing the hydrocarbon-based fuel into the pre-chamber. Unreacted hydrocarbon fuel that causes operating troubles of dry fire extinguishing equipment can be burned and removed, and pyrolytic carbon adheres to the surface of red hot coke in the pre-chamber and is generated from unreacted hydrocarbon fuel and red hot coke. The red heat coke temperature can be raised by the combustion heat of the gas to be used, and the coke wear strength, rupture strength and hot stability can be improved.

Further, by using the medium- and low-temperature carbonization coke which has been carbonized at 700 to 900 ° C. in the coke oven as the red hot coke to be charged into the pre-chamber, the cost of the coke production can be reduced by reducing the amount of carbonization in the coke oven, and the carbonization time can be reduced. The productivity can be increased by shortening the time.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory diagram of a coke dry-type fire extinguishing equipment used in Examples.

[Explanation of symbols]

 1 Cooling chamber 2 Pre-chamber 3 Coke inlet 4, 5 Blow-in nozzle 6 Blow-in port 7 Small flue 8 Circular flue 9 Flue 10 Coke cutout

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuya Kamibo 1850 Minato Minato, Wakayama, Wakayama Sumitomo Metal Industries, Ltd. Wakayama Works

Claims (2)

[Claims] 1. A method for producing a metallurgical coke in which a hydrocarbon-based fuel is blown into a pre-chamber charged with red hot coke in a coke dry fire extinguishing system to thermally decompose the hydrocarbon-based fuel and an oxygen-containing gas. A method for producing a metallurgical coke, which comprises alternately blowing the coke. 2. The method for producing metallurgical coke according to claim 1, wherein the red hot coke charged in the pre-chamber is a medium- and low-temperature carbonization coke which is carbonized at 700 to 900 ° C. in a coke oven.