JPH08245965A - Production of coke for blast furnace - Google Patents

Abstract

PURPOSE: To provide a method for producing coke in order to produce the high-strength coke with high productivity at a low cost. CONSTITUTION: This method for producing cake for a blast furnace is to calculate a gas release heat quantity Qc in a micro-space in a carbonization chamber from a difference between an atmospheric gas temperature Tf in a combustion chamber of a coke oven measured during the operation and a gas temperature Tg in the upper part of the carbonization chamber, calculate a heat-up rate HR of charged coal in the carbonization chamber and increase the quantity of a combustion gas blown into the combustion chamber when the heat-up rate HR of charged coal within the range of 60% in the central direction from the wall in the carbonization chamber is lower than 5 deg.C/min for >=10-20min in a method for preheating the coal blend at 250-350 deg.C, charging the preheated coal blend into the carbonization chamber and carbonizing the coal in the method for carbonizing the coal blend containing 40-100wt.% caking coal and the balance comprising a noncaking or a slightly caking coal and producing the coke for the blast furnace.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention expands the types of coking coal for blast furnace coke production to cope with the diversification of coal resources, improve productivity, and improve economic efficiency of coke production process. The present invention relates to a method for manufacturing blast furnace coke for reducing equipment costs.

Conventionally, a blast furnace coke is manufactured, for example, by using an apparatus having a structure as schematically shown in FIG.
First, coal that has been crushed and whose particle size has been adjusted in advance is inserted into the carbonization chamber 1 of the coke oven from the coal charging vehicle 10 on the coke oven. In order to carbonize the coal charged in the carbonization chamber 1, the preheated air and the lean gas or rich gas are burned in the combustion chamber 2 adjacent to the carbonization chamber 1. The gas temperature in the combustion chamber 2 at this time is usually about 1,100 to 1,350 ° C. The carbonization chamber 1 and the combustion chamber 2 are separated by a furnace wall made of silica brick, and the heat quantity for carbonizing the coal charged in the carbonization chamber is transferred from the combustion chamber to the coal in the carbonization chamber through the furnace wall of the silica stone brick. Reportedly. The carbonization in the carbonization chamber 1 is performed until the coal is heated to approximately 900 ° C. or higher. In the figure, 3 is a heat storage chamber, 4 is an extruder, 5 is an ascending pipe, and 6 is a dry main.

In such a conventional coke manufacturing method, since coal is charged at room temperature, the evaporation temperature of water (100 ° C.)
Until then, the temperature of the coal charged into the carbonization chamber does not rise. Furthermore, since coal has a very low thermal conductivity, heat is gradually transferred from the both side walls of the carbonization chamber toward the center, and thermal decomposition occurs. Therefore, a large temperature difference occurs between the furnace wall near the carbonization chamber and the furnace center, and 5 to 6 hours after the charging of coal, the coal near the furnace wall reaches 800 to 1,000 ° C. Even in the liquefied state, the temperature still remains at 100 ° C in the center of the carbonization chamber. As described above, the rate of temperature rise of coal in the carbonization chamber of the coke oven is as small as 2 to 3 ° C./minute, and therefore a long time of about 14 to 20 hours is required as the dry distillation time. Therefore, there is a problem that productivity is very low and energy consumption is large. Further, as described above, the temperature rise rate and the time of being placed under high temperature are very different in the vicinity of the furnace wall and in the central part of the carbonization chamber, and in the central part of the carbonization chamber, the time required for sufficient water evaporation to occur. Approximately 1/2 to 2/3 of the dry distillation time,
As a result, the coke obtained in the center of the carbonization furnace width direction is less likely to be subjected to compressive force from softening and melting to re-solidification, and is likely to become sponge coke. The coke strength in this part is low, and the strength of the entire coke is reduced. It is the cause.

Further, in the conventional blast furnace coke manufacturing method as described above, in the selection of the coking coal, the strong coking coal is mainly used because of the restriction of the quality of the blast furnace coke, and the flexibility of expanding the coal type is lacking. . Although non-caking coal is cheaper than caking coal and has a large amount of earth reserves, conventional coke production methods such as those mentioned above are more caking than caking coal. If the non-lightly caking coal, which is inferior in composition, is blended in a large amount of 30 wt% or more as a raw material for producing coke, the coke strength is significantly lowered.

As a method for shortening the carbonization time in the production of blast furnace coke, the carbonization raw material coal is preheated by carbonization and charged into the coke oven to shorten the carbonization time, improve the charging density and improve the coke density. Processes have been developed to enable quality improvements. For example, there is a pre-carbon method as a method of preheating the raw coal to about 200 ° C. and then charging it into a coke oven for carbonization. For the preheating method and the carbonization method in the coke oven, for example, see Coke Note (Fuel Association of Japan 1988). Annual edition) p. It was announced in 134 etc. However, in the pre-carbon method, preheating the coal improves the carbonization rate in the coke oven,
That is, the purpose is to improve productivity, but since the preheating temperature of coal is as low as 180 to 230 ° C., the productivity of coke is improved by only about 35% as compared with the process having no preheating step.

As a method for greatly improving the productivity of coke and diversifying the raw coal, the temperature of coal at 350 ° C.
Japanese Patent Application No. 05-267952 proposes a method of charging the coke oven after preheating to 400 ° C. However, in this method, there is a difference in the temperature rising rate during coal carbonization in the furnace width direction in the carbonization chamber during carbonization, so it is impossible to produce coke that is homogeneous and strong overall.

Therefore, the coal is preheated to improve the caking property of the coal, and the coke strength is improved by greatly increasing the room temperature rate during the carbonization of the coal in the carbonization chamber. There was a need to develop a coke manufacturing process for blast furnaces that would enable significant improvements in use and productivity.

[0008]

As described above, a method of producing high strength coke by using pre-heated coal and carbonizing it to improve productivity and using a large amount of non-fine coking coal is proposed. Development was needed.

It is an object of the present invention to provide a method for increasing the productivity while enabling the use of a large amount of non-fine coking coal as a raw material coal for producing blast furnace coke.

[0010]

SUMMARY OF THE INVENTION In order to solve the above problems, the present inventors have set up a small carbonization furnace capable of performing a simulation experiment by arbitrarily setting the thermal conditions that coal receives in the carbonization process. Detailed experiments were conducted on the relationship between the thermal conditions that coal receives, the behavior of coal in the carbonization process, and the quality of product coke, and as a result of repeated intensive studies, the temperature from above the softening start temperature to below the solidification temperature of coal during carbonization was investigated. The present invention has been completed in which the coke strength can be improved by increasing the rate of temperature rise in the temperature range (hereinafter referred to as the softening and melting temperature).

That is, the gist of the present invention is that
In a method for producing a coke for a blast furnace by dry-distilling a charging coal containing 40 to 100 wt% of caking coal and the balance consisting of non-fine coking coal, the charging coal is preheated to 250 to 350 ° C. and then transferred to a carbonization chamber. In the method of inserting and performing carbonization, the gas release heat amount Qg in the minute space in the carbonization chamber is calculated from the difference between the atmospheric gas temperature Tf in the coke oven combustion chamber and the gas temperature Tg in the upper part of the carbonization chamber, which are measured during operation. Based on the value, the heat absorption amount Qc of the charging charcoal in the minute space in the carbonization chamber is calculated, the temperature rising rate HR of the charging charcoal in the carbonization chamber is calculated, and the charging coal A method for producing blast furnace coke, characterized in that when the rate of temperature rise is less than 5 ° C / min, the rate of temperature rise of charging coal is adjusted to 5 to 30 ° C / min by the flow rate of combustion gas blown into the combustion chamber. is there.

Particularly, 60% from the wall in the carbonization chamber toward the center
It is characterized in that the temperature rising rate in the range of 5 is adjusted to 5 to 30 ° C./minute, and further that a predetermined check time is set to 10 to 20 minutes.

[0013]

The operation will be described below in detail.

FIG. 1 is a diagram showing a chamber furnace type coke oven according to the present invention. 1 is a carbonization chamber, 2 is a combustion chamber, 3 is a heat storage chamber,
4 is an extruder, 5 is an ascending pipe, 6 is a dry main, 7 is a coal dryer, 8 is a coal preheater, and 9 is a preheated coal charging hopper.

The present inventors presumed the coke production process as shown in FIG. 1 and examined the possibility of using a large amount of non-slightly caking coal for the coal having the properties as shown in Table 1.

[0016]

[Table 1]

The inventors of the present invention conducted an experiment using a small-scale carbonization furnace in order to study the improvement of coke productivity in the coke manufacturing process for a blast furnace using the coke oven shown in FIG. As a result, the preheating temperature of coal is set to 250 to 350 ° C. If the temperature is less than 250 ° C., the purpose of drying preheating for significantly improving productivity cannot be sufficiently achieved.
Above 0 ° C, gas is generated from coal. Therefore, the preheating temperature is set to 250 to 350 ° C. in order to achieve the purpose of dry preheating and suppress gas generation.

Coal charged into a coke oven usually has a particle size of 3
It is crushed so that mm or less becomes 80 wt% or more.

The carbonization of coal is carried out under the conditions that the temperature of the coal charged into the coke oven is 250 to 350 ° C., the gas temperature in the combustion chamber is 1,000 to 1350 ° C., and the carbonization time is 6 to 10 hours. The so-called coking reaction proceeds due to the thermal decomposition / polycondensation reaction of the coal.

In order to conduct heat transfer analysis of the carbonization process in the coke manufacturing process for the blast furnace by the coke oven shown in FIG. It was created. This model is based on the heat transfer model for the heat transfer behavior of coke in the carbonization process as shown in Figs. 4 to 6, with specific heat, thermal conductivity, heat of reaction, gas generation, and coal charge density during carbonization. , A simulation model that incorporates coal volume and density changes as a temperature function.

Using the simulation model, the endothermic amount Qc of the coal blend in the carbonization chamber was calculated from the difference in the measured values of the atmospheric gas temperatures in the upper part of the combustion chamber and the upper part of the carbonization chamber during the carbonization process in the coke oven, and this value was calculated. Based on this, the temperature rise rate of the blended coal is calculated, and the temperature rise rate in the softening and melting temperature range of the blended coal in the carbonization chamber is calculated by the heat transfer equation.

The inventors of the present invention have shown the properties shown in Table 1 and used as a typical raw material for producing coke for a blast furnace, which is a typical strongly caking coal A (VM 24.8%, maximum fluidity 2.7) and non-fine caking. Charcoal B charcoal (VM 33%, maximum fluidity 1.0) was used to produce coke by dry distillation using a small drying furnace that can simulate the thermal conditions that coke receives during dry distillation. went.

The inventors diligently studied the relationship between the temperature rising rate of coal and the coke strength when carbon preheated to 250 to 350 ° C. was carbonized in the carbonization chamber. First, the relationship between the temperature rising rate of the coal and the coke strength in the temperature range from the softening start temperature of the coal to the solidification temperature (hereinafter referred to as the softening and melting temperature range) was investigated using the coking coal A coal. As a result, as shown in FIG. 3, it was found that the coke strength was improved when the heating rate of coal in the softening and melting temperature range was 5 ° C./min or more.

In order to further investigate the relationship between the softening and melting temperature range of coal and the coke strength in the width direction of the coke chamber, the inventors of the present invention described above using non-fine coking coal B charcoal having the properties shown in Table 1. A carbonization experiment was carried out using a small carbonization furnace. As a result, as shown in Table 2, a high-strength blast furnace coke can be obtained by increasing the temperature rising rate in the softening and melting temperature range of coal to 5 ° C./min or more in the range of 60 wt% or more in the carbonization chamber. I found what I could do.

[0025]

[Table 2]

Therefore, a specific method of applying the present technology to driving was examined.

4 to 6 show a method of calculating the adjustment amount of the fuel gas blown into the combustion chamber of the coke oven. First, the heat transfer amount Qf from the combustion chamber to the carbonization chamber, the heat transfer amount Qg to the coal blending coal in the carbonization chamber, and the heat absorption amount Qc of the coal blending due to the difference between the combustion chamber upper gas temperature Tf and the carbonization chamber upper gas temperature Tg measured during operation. To calculate. Based on this value, the heating rate of the blended coal was calculated by heat transfer calculation, and the charging rate in the range of 60% or more from the wall in the carbonization chamber toward the center was the rate of temperature rise in the softening and melting temperature range of the blended coal. Check if is above 5 ° C / min.

Although the carbonization of coal in the carbonization chamber gradually progresses toward the center due to heat transfer from both walls of the carbonization chamber, since the thermal conductivity of coal is small, the rate of temperature rise above 30 ° C./min. Cannot be secured. Therefore, the upper limit of the heating rate is 30 ° C.
/ Min.

From the above check results, when the temperature rising rate of the charging coal of 60 wt% or more in the coke oven carbonization chamber is less than 5 ° C./min, the adjustment amount of the flow rate of the fuel gas blown into the combustion chamber is shown in FIG. , 6 is calculated by the following method.

1 for the amount of fuel gas blown into the combustion chamber
Using the above simulation model, the atmospheric gas temperature in the combustion chamber, the heat transfer amount to the carbonization chamber, the heat transfer amount to coal in the carbonization chamber, and the heat absorption amount of coal in the carbonization chamber when the adjustment amount of the amount of gas per time is changed are used. The temperature distribution of the coal in the carbonization chamber is estimated by sequentially calculating the minute space. Based on this estimated value, it is judged whether or not the temperature rising rate in the softening and melting temperature range of the charging coal is 5 ° C./min or more, and the appropriate adjustment amount of the fuel gas amount is calculated by repeated calculation.

Based on this finding, the present inventors further conducted the following examination. If the temperature rise rate of the charging coal is lower than 5 ° C./minute, it takes a long time to return the temperature rising rate to a stable state, which causes the temperature rising rate of the charging coal to decrease. Therefore, FIG. 8 shows the results of an examination of the relationship between the checking time of the temperature rise rate of charging coal and the coke strength. As can be seen from this figure, in the actual plant, the temperature increase rate of the charging coal can be controlled to 5 ° C./minute or more when the checking time of the temperature rising rate of the charging coal is set to 10 to 20 minutes, The coke strength could be improved. Therefore, it is preferable that the time for calculating the rate of temperature increase be 10 to 20 minutes.

Based on the gas amount adjustment amount calculated here,
Adjusting the amount of fuel gas blown into the combustion chamber, adjusting the atmospheric gas temperature in the combustion chamber, 60w of charging coal in the carbonization chamber
By controlling the temperature rising rate of the blended coal in the softening and melting temperature range of 5% / min or more to t% or more, the caking property of coal is improved and the coke strength is improved.

At this time, the gas temperature in the combustion chamber is 1,000 to
It is 1,350 ° C.

As a result, the present invention has been completed which has high productivity and enables a large amount of non-caking coal to be used.

In the present specification, the maximum fluidity and the solidification temperature are the maximum fluidity measured by a Giessler plastometer as shown in JIS M8801,
And the value of the solidification temperature.

In this specification, the coke strength is JIS K.
The coke sample is measured by the drum strength test method shown in 2151 and is expressed by the weight ratio of the residual coke on the 15 mm sieve after 150 rotations.

In the present specification, non-slightly caking coal is defined as coal having a caking strength index (CI) of less than 80. The measuring method of the cohesive strength index (CI) is as of the technical term of coal utilization technology (Fuel Association of Japan, 1983 edition) p. As shown in 255, 1 g of coal having a viscosity of 0.25 mm or less has a particle size of 0.25 m.
A mixture of 9 g of powder coke of m or more and 0.3 mm or less was placed in a magnetic crucible and coke-dried at 900 ° C. for 7 minutes to form coke. The obtained coke was passed through a 0.42 mm sieve and stayed on the sieve. The amount is Ag,

[0038]

[Equation 1]

When the blending ratio of the caking coal is less than 40 wt%, the caking property of the blending coal is insufficient, and it is impossible to produce coke having sufficient strength as blast furnace coke. Therefore, the mixing ratio of caking coal is limited to 40 to 100 wt%. Therefore, the blending ratio of the non-slightly caking coal is 60 to 0 wt%.

In the present invention, the rate of temperature rise in the softening and melting temperature range of the charged coal is 5 wt.
If it is less than the above range, the effect of improving the coke strength cannot be obtained. Therefore, the temperature rising rate in the softening and melting temperature range of the charged coal is 5 ° C /
60% from the wall of the carbonization chamber toward the center
Defined as% or more.

The effects of the present invention will be described below with reference to examples.

[0042]

【Example】

Example 1 Two types of coal shown in Table 1 were used as blended coal. Caking coal A
The blending ratio of the charcoal and the non-slightly caking coal B charcoal was set to 70:30 by weight, and the blended charcoal was dry-distilled using a small scale carbonization furnace. In oven width of the small carbonization furnace 420 mm, furnace wall ordinary silica brick (Density: 1.74g / cm ³⁾ between the combustion chamber and the carbonizing chamber higher density than high density bricks (density: 1.81 g / cm ³ )It was used.

In Example 1, according to the method of the present invention, 30
Coal preheated to 0 ° C. was charged into the carbonization chamber, and coke was produced under dry distillation conditions of 7 hours according to dry distillation pattern A shown in FIG.
The furnace width of the carbonization chamber is 420 mm. The atmospheric gas temperature Tf in the combustion chamber measured during operation is 1,050 to 1,350.
C, the gas temperature Tg of the upper part of the carbonization chamber is 1,020-1,3
It is 20 ° C. At this time, the calculated value of the gas release heat amount Qg in the minute space in the carbonization chamber is 2,150 to 2,600 kc.
al / Hr, and the heat absorption amount Qc of the charging coal in the agitation space of the carbonization chamber is 1,100 to 1,650 kcal / H.
r. The estimated value HR of the temperature rising rate of the charging coal is 5 ° C./min or more at 100% in the central direction from the wall in the carbonization chamber. As a result of actually measuring the temperature rising rate of coal in the carbonization chamber with a thermocouple, it was found to be 1 in the range of 70 mm from the furnace wall brick in the carbonization chamber.
0.4 ℃ / min, 70 ~ 140mm from furnace wall brick in carbonization chamber
The rate of temperature rise of coal in the range is 6.8 ° C./min, and the rate of temperature rise of coal in the range of 140 to 210 mm from the brick wall of the carbonization chamber is 5.5 ° C./min. That is, 100 wt of charged coal
A temperature increase rate of 5 ° C./min or more was ensured in the range of%. The coke obtained by the main carbonization has a strength of 83.2.

Example 2 In Example 2, according to the method of the present invention, coke preheated to 300 ° C. was produced in the dry distillation pattern B shown in FIG. 7 under the dry distillation condition of 7 hours to produce coke. The gas temperature Tf in the combustion chamber measured during operation is 1,050 to 1,200 ° C., and the gas temperature Tg in the upper part of the carbonization chamber is 1,020 to 1,150 ° C. The calculated value of the gas release heat amount Qg in the minute space in the carbonization chamber at this time is 1,510 to 1,850 kcal / Hr, and the heat absorption amount Qc of the charging coal in the minute space of the carbonization chamber is Qc.
Is 1,100 to 1,350 kal / Hr. The estimated value HR of the temperature rising rate of charging coal is 5 ° C./min or more at 70% in the central direction from the wall in the carbonization chamber. As a result of actually measuring the rate of temperature rise of the coal in the carbonization chamber with a thermocouple, it was found that the temperature was 8.5 ° C / min in the range of 70 mm from the furnace wall brick in the carbonization chamber, and the range of 70 to 140 mm from the furnace wall brick in the carbonization chamber. Heating rate of 5.3 ℃ / min, 140 ~ 210m from the furnace wall brick in the carbonization chamber
The rate of temperature rise of coal in the range of m is 3.9 ° C / min. That is, 67 wt% of the charged coal was 5% by this carbonization method.
Dry distillation is carried out at a temperature rising rate of not less than ° C / min. As a result, the coke strength obtained was 82.5%, and coke having sufficient strength as coke for blast furnace was obtained in both Examples 1 and 2. Comparative Example 1 On the other hand, in Comparative Example 1, dry carbon at 300 ° C. was charged into a carbonization furnace according to the conventional coke oven operation method, and
Dry distillation was carried out at a constant heat pattern of 100 ° C. for 7 hours. As a result, the strength of the obtained coke was as low as 78.4%, and the strength was insufficient as blast furnace coke.

Example 3 In Example 3, two kinds of coal shown in Table 1 were used as blended coal. The blending ratio of the caking coal A coal and the non-slightly caking coal B coal was set to 60:40 in weight ratio, and the blended coal was dry-distilled using the small-scale carbonization furnace. According to the method of the present invention, the carbonization conditions are as follows: Coal preheated to 300 ° C. is charged into the carbonization chamber, and carbonization pattern B shown in FIG.
Coke was produced by dry distillation under the conditions of dry distillation for 7 hours. The atmospheric gas temperature Tf in the combustion chamber measured during operation is 1,0
At a temperature of 50 to 1,200 ° C, the gas temperature Tg in the upper part of the carbonization chamber is 1,020 to 1,150 ° C. At this time, the calculated value of the gas release heat amount Qg in the minute space in the carbonization chamber is 1,51
0 to 1,850 kcal / Hr, and the heat absorption amount Qc of the charging coal in the minute space of the carbonization chamber is 1,100 to 1,
It is 350 kcal / Hr. The estimated value HR of the temperature rising rate of the charging coal at this time is 5 ° C./min or more at 70% in the central direction from the wall in the carbonization chamber. As a result of actually measuring the temperature rising rate of the coal in the carbonization chamber with a thermocouple, it was 9.0 ° C / min in the range of 70 mm from the furnace wall brick in the carbonization chamber, and in the range of 70 to 140 mm from the furnace wall brick in the carbonization chamber. Heating rate is 6.7 ℃
/ Min, the rate of temperature rise of coal in the range of 140 to 210 mm from the furnace wall brick in the carbonization chamber is 5.3 ° C / min. That is,
In this carbonization, 100 wt% of the charged coal is carbonized at a temperature rising rate of 5 ° C / min or more. As a result, the strength of the obtained coke was 81.2%, which is sufficient as blast furnace coke.

Comparative Example 2 On the other hand, in Comparative Example 2, according to the conventional coke oven operation method, dry carbon at 300 ° C. was charged into a carbonization furnace to obtain 1,100.
Dry distillation was carried out at a constant heat pattern at ℃ for 7 hours. As a result,
The strength of the obtained coke was as low as 73.4%, which was insufficient as blast furnace coke.

Comparative Example 3 In Comparative Example 3, the mixing ratio of the caking coal A coal and the non-slightly caking coal B coal whose properties are shown in Table 1 was set to 30:70 by weight, and the small coal distillation furnace was used as the mixing coal. I made a dry distillation. According to the method of the present invention, the carbonization conditions are as follows.
Coke was produced by dry distillation under dry distillation conditions of 7 hours in the dry distillation pattern B shown in FIG. The atmospheric gas temperature Tf in the combustion chamber measured during operation is 1,050 to 1,200 ° C., and the gas temperature Tg in the upper part of the carbonization chamber is 1,020 to 1,150 ° C. At this time, the calculated value of the gas release heat amount Qg in the minute space in the carbonization chamber is 1,510 to 1,850 kcal / H.
r, and the heat absorption amount Qc of the charging coal in the minute space of the carbonization chamber is 1,100 to 1,350 kcal / Hr. The estimated value HR of the temperature rising rate of the charging coal at this time is 5 ° C./min or more at 70% in the central direction from the wall in the carbonization chamber. As a result of actually measuring the rate of temperature rise of the coal in the carbonization chamber with a thermocouple, it was found to be 8. within a range of 70 mm from the brick wall of the carbonization chamber.
The heating rate of coal in the range of 9 ° C / min, 70 to 140 mm from the furnace wall brick in the carbonization chamber is 5.3 ° C / min, and the heating rate of coal in the range of 140 to 210 mm from the furnace wall brick in the carbonization chamber is It was 3.9 ° C./min. That is, in this dry distillation test, 67 wt% of the charged coal was dry distilled at a temperature rising rate of 5 ° C./min or more.
As a result, the coke obtained had a coking coal content of 4
Since it is less than 0 wt%, the strength is remarkably low as 61.2%, and the strength as coke in the blast furnace is insufficient.

Example 4 The mixing ratio of caking coal A coal and non-slightly caking coal B coal whose properties are shown in Table 1 in FIG. 8 was set to 70:30 in weight ratio, and the mixing coal was produced by using the small-scale carbonization furnace. It was carbonized. The carbonization conditions are as follows. According to the method of the present invention, coal preheated to 300 ° C. is charged into the carbonization chamber, and the present invention is applied to the carbonization pattern B shown in FIG.

The atmospheric gas temperature Tf in the combustion chamber measured during operation is 1,050-1,200 ° C., and the gas temperature Tg in the upper part of the carbonization chamber is 1,020-1,150 ° C. The calculated value of the gas release heat amount Qg in the minute space in the carbonization chamber at this time is 1,510 to 1,850 kcal / Hr, and the heat absorption amount Qc of the charging coal in the minute space of the carbonization chamber is 1,
It is 100 to 1,350 kcal / Hr. The estimated value HR of the temperature rising rate of the charging coal at this time is 5 ° C./min or more at 70% in the central direction from the wall in the carbonization chamber. As a result of actually measuring the temperature rising rate of the coal in the carbonization chamber with a thermocouple, it was found that coal in the range of 70 mm from the furnace wall brick in the carbonization chamber was 8.9 ° C./min, and in the range of 70 to 140 mm from the furnace wall brick in the carbonization chamber. Heating rate of 5.3 ℃ / min, 140 ~ 21 from the furnace wall brick in the carbonization chamber
The heating rate of coal in the range of 0 mm is 3.9 ° C / min.

In the conventional operation, since the checking time of the temperature rising rate of coal in the carbonization chamber was not constant,
The coke strength was low. Next, as in the present invention, the temperature check time was set to 10 to 20 minutes, and the temperature rise rate of the charging coal was adjusted to 5 ° C or higher by the flow rate of the combustion gas, and as a result, the coke strength was improved to 80% or higher.

The above results are shown in Table 3.

[0052]

[Table 3]

[0053]

INDUSTRIAL APPLICABILITY As described above, the present invention expands the coal types of the raw material coal for producing coke for blast furnaces to cope with the diversification of coal resources, improve the productivity, and improve the economical efficiency of the coke production process. , And a method for reducing equipment costs, and the technical and economic effects of the present invention are extremely large.

[Brief description of drawings]

FIG. 1 is an overall flow diagram of a coke manufacturing process to which the present invention is applied.

FIG. 2 is an overall flow diagram of a conventional coke manufacturing process.

FIG. 3 is a graph showing the effect of the present invention and a graph showing the relationship between the temperature rising rate of coal and the coke strength.

FIG. 4 is a diagram showing a heat transfer model in the carbonization process of coal in a coke oven.

FIG. 5 is a diagram showing calculation of a flow rate adjustment amount of a combustion gas amount blown into a combustion chamber.

FIG. 6 is a diagram showing calculation of a flow rate adjustment amount of a combustion gas amount blown into a combustion chamber.

FIG. 7 is a diagram showing a dry distillation pattern according to an example of the present invention.

FIG. 8 is a graph showing the relationship between the temperature increase rate check time and the coke strength of the present invention.

[Explanation of symbols]

1 ... Carbonization chamber 2 ... Combustion chamber 3 ... Heat storage chamber 4 ... Extruder 5 ... Rise pipe 6 ... Dry main 7 ... Coal dryer 8 ... Coal preheater 9 ... Preheated coal charging hopper

Claims (3)

[Claims] 1. A method for producing a blast furnace coke by dry-distilling a charging coal containing caking coal in an amount of 40 to 100 wt% and the balance being non-fine coking coal, and preheating the charging coal to 250 to 350 ° C. After that, when charged into the carbonization chamber and subjected to carbonization, the gas release heat amount Qg in the minute space in the carbonization chamber is determined by the difference between the atmospheric gas temperature Tf in the coke oven combustion chamber and the carbonization chamber upper part Tg measured during operation. Calculated, based on this value, the heat absorption amount Qc of the charging coal in the minute space in the carbonization chamber is calculated, the temperature increase rate HR of the charging coal in the carbonization chamber is calculated, and for a predetermined check time or more, A method for producing blast furnace coke, characterized in that when the temperature increase rate of charging coal is less than 5 ° C, the temperature increase rate of charging coal is adjusted to 5 to 30 ° C by the flow rate of combustion gas blown into the combustion chamber. 2. The method for producing coke for a blast furnace according to claim 1, wherein the temperature rising rate of the charged coal in the range of 60% from the wall in the carbonization chamber toward the center is adjusted to 5 to 30 ° C./min. . 3. The method for producing blast furnace coke according to claim 1, wherein the predetermined check time is set to 10 to 20 minutes.