JPH07126626A - Production of blast furnace coke - Google Patents

Abstract

PURPOSE:To provide a process for the production of blast furnace coke capable of decreasing the coke quality difference between the wall side and the core side of a coke oven, stabilizing the blast furnace operation and preventing the formation of coke having extremely low quality even from coal having lower cost and accordingly reducing the production cost of coke. CONSTITUTION:Coal is charged into a coke oven after heating at a prescribed temperature between the softening-initiation temperature (Tf) of the coal and Tf-50 deg.C (excluding Tf) and the flue temperature of the combustion chamber of the coke oven is controlled to 950-1100 deg.C immediately after charging, 1200-1350 deg.C for 1-3hrs after the charging operation and 950-1100 deg.C before the discharge of coke.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel method for producing blast furnace coke. More specifically, the present invention relates to a method for producing blast furnace coke, which can reduce the difference in coke quality between the furnace wall side and the center of the furnace by coking.

[0002]

2. Description of the Related Art Conventionally, a blast furnace coke is, for example, as shown in FIG.
It is manufactured using an apparatus having a configuration as outlined in. That is, first, a certain amount of coal made of coking coal which has been finely pulverized and whose particle size has been adjusted in advance is loaded into a charging vehicle on the carbonization furnace 10 in a fixed amount, and then the carbonization chamber 12 of the carbonization furnace 12 and the upper part of the carbonization chamber 12 are loaded. It is charged from the charging port 13 of. The temperature of coal at the time of charging is normal temperature (20 to 30 ° C). In the carbonization furnace 10,
Air and poor gas or rich gas (not preheated) preheated in the refractory brick heat storage chamber 14 at the lower portion of the carbonization chamber 12 rises to the upper portion and is burned at the combustion chamber 15.
The flue temperature at this time is usually 1200 to 1350 ° C.
It is a degree. The carbonization chamber 12 and the combustion chamber 15 are partitioned by a wall surface made of silica stone and are alternately arranged, and the combustion heat of the combustion chamber 15 is transferred to the coal in the carbonization chamber 12 through the silica stone brick. Carbonization in the carbonization chamber 12 is 1000
It is performed until it is heated to about ℃. Then carbonization chamber 1
2 The furnace lids on both sides are opened, and the rack 17 installed in the extruder 16 pushes out the generated red hot coke. The extruded coke is loaded into the coke bucket 19 through the grid of the coke guide car, and then guided to the coke dry fire extinguisher (CDQ) by a train (not shown),
The CDQ is contacted with an inert gas, cooled to about 200 ° C., and taken out.

In such a conventional carbonization process, in the coke oven, since the coal is charged at room temperature, the temperature of the coal charged in the furnace does not rise up to the evaporation temperature of water (100 ° C.). Further, since the thermal conductivity of coal is extremely low, heat is gradually transferred from both side walls of the carbonization chamber 12 toward the center, and thermal decomposition occurs. Therefore, there is a large temperature difference between the vicinity of the furnace wall of the carbonization chamber and the center of the furnace, and even after 6 hours have passed since the charging of coal, 800
In some cases, the temperature of coal in the central part of the furnace still remained at 100 ° C even when the temperature reached up to 1000 ° C and the coke was formed. As described above, since the average temperature rise temperature of coal in the carbonization furnace 10 is very slow at 3 to 5 ° C./minute, the carbonization time is about 14 to 20 hours, which requires a long period of time. It was a big problem. Further, as described above, the temperature rise rate and the time of being placed at a high temperature are very different in the vicinity of the furnace wall and in the central part of the furnace, and in the central part of the furnace, the time required for complete evaporation of water is It occupies about 1/2 to 2/3, and as a result, the coke obtained in the central part of the furnace is less likely to be subjected to compressive force from softening and melting to re-solidifying, and is likely to become sponge coke. After the dry distillation time, a storage time of about 1 to 3 hours was provided, which promoted a longer process life.

In the production of such blast furnace coke, as a method of shortening the carbonization time, 100 to 2 in a gas stream heating system is used before charging the charged coal into the carbonization furnace.
It is known to dry preheat to about 00 ° C. In such a method, the bulk density of the coal charged in the carbonization furnace can be increased by about 10% as compared with the coal containing normal water,
As a result, the dry distillation time can be reduced by about 30% as compared with the case where ordinary coal is charged.

However, even with such dry coal charging (200 ° C. for preheated coal charging), even if the temperature near the furnace wall is 800 ° C. or more 6 hours after coal charging, the coal in the center of the furnace has 4
It was about 00 ° C. Furthermore, due to the improvement in the thermal efficiency of the dry distillation furnace in recent years, the total of the energy required for this preheating and the energy required for the subsequent dry distillation is greater than the energy required for the dry distillation when charged into the dry distillation furnace at room temperature.
Almost unchanged or slightly higher, and no advantage in terms of energy consumption is seen.

Further, the furnace temperature is raised in the initial stage of carbonization, and the rate of temperature rise is increased while the coal is softened and melted to improve the caking property and to make the coke quality uniform. It is known that ACC-II which lowers the However, even with this method, the rate of temperature rise is at most about several tens of degrees Celsius / minute, the rate of improvement in productivity does not change, and the coke quality is not uniformized sufficiently.

[0007]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a novel method for producing blast furnace coke.

Another object of the present invention is to provide a method for producing coke for a blast furnace which can reduce the difference in quality of coke between the furnace wall side and the center of the coke furnace.

Another object of the present invention is to provide a method for producing blast furnace coke, which can shorten the dry distillation time.

[0010]

The present invention is a method for producing coke by rapidly heating coal to a temperature range within a range from the softening start temperature of the coal to a temperature 50 ° C. lower than the softening start temperature. In, the flue temperature of the combustion chamber of the coke oven was set to 950 to 1100 ° C immediately after charging, the flue temperature was raised to 1200 to 1350 ° C for 1 to 3 hours thereafter, and the flue temperature was lowered to 950 to 1100 ° C before discharging. It is characterized by

In a method of rapidly heating coal to a temperature range within a range from the softening start temperature of the coal to a temperature 50 ° C. lower than the softening start temperature, and then hot dipping in a coke oven. Immediately after charging, the flue temperature of the combustion chamber of the coke oven is set to 950 to 1100 ° C, the flue temperature is raised to 1200 to 1350 ° C for 1 to 3 hours thereafter, and the flue temperature is lowered to 950 to 1100 ° C before discharging. Is characterized by.

[0012]

In the method for producing blast furnace coke according to the present invention, the coal has a predetermined temperature within a range (not including the softening start temperature) from the softening start temperature of the coal to a temperature lower by 50 ° C. than the softening start temperature. By rapidly heating to, it is possible to improve the caking property of coal and further improve the productivity. Also, since the coal is heated up to just before the softening start temperature, the dry distillation pattern in the dry distillation furnace is set to 950 at the initial stage of charging.
By suppressing the temperature to a relatively low value of ~ 1100 ° C, a rapid rise in the coal temperature near the furnace wall is suppressed, and 120 hours after 1 to 3 hours.
The temperature is raised from 0 to 1350 ° C, the temperature of the coal in the central part is raised, and at the time of discharge, it is almost 950 to 1100 which is almost the same as the initial charging.
By setting the temperature to a relatively low value of 0 ° C., it is possible to suppress excessive temperature rise of the coke temperature and obtain coke having uniform coke quality.

[0013]

[Examples] Ten kinds of coal blends were crushed to 3 mm or less, rapidly heated to 397 ° C by the apparatus shown in Fig. 1, and then dried by the dry distillation pattern shown in Fig. 2A. As a comparative example, the same 10 kinds of blended coal was crushed to 3 mm or less, and directly charged into the carbonization furnace from the hopper of 11 without heating rapidly with the device shown in FIG. 1, and in the carbonization pattern of B and C of FIG. It was carbonized.

It is understood from FIGS. 2, 3 and 4 that by adopting the dry distillation temperature pattern in this embodiment, coke having uniform coke quality such as porosity can be obtained in a short time.

[0015]

According to the present invention, since uniform coke can be provided to the blast furnace, the blast furnace work is stabilized.

Further, even if coal which is cheaper than before is used,
Since coke of extremely deteriorated quality is not produced, the cost of producing coke can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic view of a blast furnace coke manufacturing apparatus of the present invention.

FIG. 2 is a diagram showing an example of a carbonization pattern after charging coal according to the present invention.

FIG. 3 is a diagram showing a coke temperature distribution immediately after discharge according to the present invention.

FIG. 4 is a diagram showing a porosity distribution of the coke of the present invention.

[Explanation of symbols]

10 ... Dry distillation furnace, 11 ... Hopper, 12 ... Carbonization chamber, 13 ... Charging port, 14 ... Heat storage chamber, 15 ... Combustion chamber, 16 ... Extruder, 17 ... Rack, 19 ... Coke bucket, 20 ... Coke reforming device, 21 ... dryer,
22 ... Preheater, 23 ... Hot air stove,
24 ... Molding machine, 25 ... Pre-chamber,
26 ... Cooling chamber.

Claims (2)

[Claims] 1. A method for producing coke by rapidly heating coal to a temperature range within a range from a softening start temperature of the coal to a temperature 50 ° C. lower than the softening start temperature,
950 immediately after charging the flue temperature of the combustion chamber of the coke oven
˜1100 ° C., the flue temperature for 1 to 3 hours thereafter is raised to 1200 to 1350 ° C., and the flue temperature is lowered to 950 to 1100 ° C. before discharging. 2. A method in which coal is rapidly heated to a temperature range within a range from the softening start temperature of the coal to a temperature lower by 50 ° C. than the softening start temperature of the coal, and then hot-forming, followed by dry distillation in a coke oven. , The flue temperature of the combustion chamber of the coke oven was set to 950 to 1100 ° C. immediately after charging, and then 1 to
Raise the flue temperature for 3 hours to 1200-1350 ° C,
A method for producing blast furnace coke, which comprises reducing the flue temperature to 950 to 1100 ° C. before discharging.