JP3519803B2 - Coke production method by rapid heating of coal - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing coke in which inferior coal having insufficient softening and melting properties is reformed and used in a large amount. [0002] Conventionally, a large amount of inferior coal is blended in a furnace,
In order to produce coke, there is no caking property, so that 5% or more cannot be blended with ordinary coal blends. Therefore, in order to mix 5% or more, there is no other way but to add a caking filler or to increase the mixing ratio of coal having high caking properties. For this reason, it is expensive economically and resource-wise. [0003] Therefore, there is a technique for producing molded coke as a technique that can use a large amount of inferior coal. In this method, coal is molded using a binder. Thus, the distance between the coal particles is shortened, and the coke is formed with a reduced caking property by molding the coal. However, there are difficulties such as the need to use expensive binders and the difficulty of dry distillation in a room coke oven. In a method of rapidly heating coal to produce coke, there is a preheating coal charging technique (for example, Introduction to Carbon Materials: Carbon Materials Society of Japan, 1984, p.12).
3). However, this method is aimed at drying the coal,
Heating up to 250 ° C. Further, any of the methods for rapidly heating coal to a high temperature is a coal pyrolysis method for obtaining a large amount of gas (for example, Japanese Unexamined Patent Publication No. Hei 6-179).
871), which is not a method for producing coke. SUMMARY OF THE INVENTION In view of the above-mentioned state of the prior art, the present invention reforms inferior coal without using a binder and uses a large amount of inferior coal in a room coke oven. To produce coke. According to the present invention, three types of inferior coal having a reflectance of 0.9 or less are used.
After rapidly heating the coal containing less 0 wt% or more 80 wt%, a process for producing coke by the dry distillation, flow
In the layer, the coal is heated at a temperature of at least 90 ° C./min to a temperature 5 to 10 ° C. lower than the softening start temperature of the coal, which is the upper limit temperature of heating ,
° C. / min after heating by the following heating rate, a coking process according coal rapid heating, characterized by dry distillation at room formula coke oven. Since coal having a reflectance of more than 0.9 is caking coal, the present invention is directed to coal having a reflectance of 0.9 or less. By rapidly heating the inferior coal having a reflectance of 0.9 or less, the caking properties of the coal can be brought out, so that a large amount of the inferior coal can be used in a room coke oven. In this case, the coal containing 30 wt% or more and 80 wt% or less of the inferior coal having a reflectance of 0.9 or less, and the other coal is caking coal is that if the inferior coal is less than 30 wt%, the coke is formed without rapid heating. If the inferior coal exceeds 80 wt%, coking cannot be performed even by rapid heating. Here, coal other than inferior coal is caking coal. In the present invention, coal heated to around 400 ° C. is charged into a room coke oven, so that the carbonization time in a conventional room coke oven can be greatly reduced, and thus productivity is improved. [0007] First, in order to examine the rapid heating temperature and the rate of temperature rise, an examination was made using an apparatus capable of measuring caking properties from the entry of a needle. As shown in FIG. 1, a coal sample is placed on a sample table 9 and the load is determined by a load control unit. The temperature of the coal sample is measured while the temperature of the coal sample is increased by setting the rate of temperature increase by the temperature controller. At this time, a 90 gr load is applied to the needle, and when the coal starts softening and melting by heating, the needle enters the coal. The larger the amount of penetration, the better the softening property. FIG. 2 shows the amount of the needle entering while the temperature is raised to 500 ° C. at a rate of 100 ° C./min, and FIG. In both figures, a change in the amount of needle entry indicates a temperature change. FIG. 4 raises the temperature to 410 ° C. and FIG. 5 raises the temperature to 420 ° C. at a rate of 100 ° C./min.
While the temperature was raised to 00 ° C., the penetration amount of the needle was examined. 6 and 7 show that the heating rate was 85 ° C./min and 9
It shows the relationship between the amount of needle penetration () and the temperature () when heating to 500 ° C. at 0 ° C./min. As shown in FIG. 1, the needle was advanced while heating, and the effect of improving the cohesion of coal (Witbank coal, reflectance 0.82) by rapid heating was measured using a device capable of measuring the viscosity. FIGS. 2 and 3 show the penetration speed of the needle at a heating rate of 100 ° C./min and 10 ° C./min up to 500 ° C. It can be seen that when heated at a heating rate of 100 ° C./min, the needle penetrates deeply and the caking property has developed. At this time, in FIG. 2, the temperature at the intersection of the gradient at which the needle enters gently and the gradient at which the needle rapidly enters is defined as the softening start temperature. The softening start temperature at this time is 428 ° C. At a heating rate of 10 ° C./min, the needle does not enter sufficiently. That is, no improvement in caking property is observed. However, in order to put the coal rapidly heated to 500 ° C into the carbonization furnace, it is difficult to load it into the carbonization furnace because it has already been softened and melted, making it difficult to handle. It is difficult to develop sclerosis. Therefore, it was examined how many times the rapid heating could improve the caking property. As a result, at 410 ° C., no improvement in the caking property was observed (FIG. 4), but when rapidly heated to 420 ° C., an improvement in the caking property was observed (FIG. 5). 100
The softening start temperature at a heating rate of ° C./min is 428 ° C. Therefore, 410 ° C. (18 ° C. lower than the softening start temperature)
As a result of studying by changing the temperature in addition to the rapid heating up to 420 ° C. (8 ° C. lower than the softening start temperature), it was found that it was necessary to heat to a temperature 5 to 10 ° C. lower than the softening start temperature. [0011] In order to investigate the effect of the type of coal, inferior coal having a reflectance of 1.0 or less was examined in the same manner. Improvement was seen. Here, 10 ° C from the softening start temperature
When the temperature is extremely low, sufficient caking property cannot be obtained, and when the temperature is lower than the softening start temperature by less than 5 ° C., the softening proceeds too much, and the caking property required for dry distillation in a chamber-type coke oven is not obtained. Absent. The results of 85 ° C./min (FIG. 6) and the results of 90 ° C./min (FIG. 7) are shown for examining the rate of temperature rise. From this result, it was found that a heating rate of 90 ° C./min or more was required as a heating rate for reforming coal. The heating rate is 500 ° C /
Exceeding the value is undesirable because the coke strength is lowered as shown in Table 1. Therefore, the heating rate is preferably from 90 ° C./min to 500 ° C./min. Example 1 Witbank coal, which is a poor quality coal (the softening start temperature measured by an apparatus for inserting a needle while heating as shown in FIG. 1 was 428 ° C. as shown in FIG. 2) 50
420 wt% and 50 wt% of Gunniera charcoal which is caking coal
C. in a fluidized bed at a heating rate of 80.degree. C./min to 600.degree. C./min. Table 1 shows the strength of the obtained coke.
Shown in As a result, when the temperature was raised to 420 ° C. at a rate of 90 ° C./min or more, the coke strength was good at a coke strength of 75 (DI ¹⁵⁰ ₁₀ ) or more. [Table 1] As described above, by rapidly heating the coal, the cohesion is improved, and this allows a large amount of steam coal to be used in a room coke oven, and furthermore, the carbonization time This is an extremely excellent effect that the productivity can be improved by shortening the length.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a needle entry type viscometer, FIG. 2 is a diagram showing needle entry when the temperature is raised to 500 ° C. at 100 ° C./min. FIG. 4 shows the penetration of the needle when the temperature is raised to 500 ° C. at 10 ° C./min.
FIG. 5 is a diagram showing the penetration of a needle when the temperature is increased to 00 ° C. at a rate of 10 ° C./min.
FIG. 6 shows the entry of the needle when the temperature is increased to 00 ° C. at 10 ° C./min. FIG. 6 shows the entry of the needle when the temperature is increased to 500 ° C. at 85 ° C./min. FIG. 6 is a diagram showing the entry of a needle when the temperature is increased at 90 ° C./min. [Description of Signs] 1 Spring 2 Permanent magnet 3 Differential transformer (coil) 4 Differential transformer (core) 5 Manometer 6 Electric furnace 7 Thermocouple 8 Needle 9 Sample

Continuation of the front page (72) Inventor Yoshihisa Sakurai 20-1 Shintomi, Futtsu-shi, Chiba Nippon Steel Corporation Technology Development Division (56) References JP-A-7-166166 (JP, A) JP-A Sho58 -122982 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C10B 57/10 C10B 53/08

Claims (1)

(57) [Claims 1] 30 wt% of inferior coal having a reflectance of 0.9 or less.
In a method for producing coke by rapidly heating a coal containing at least 80 wt% and then carbonizing the coal, the coal is heated in a fluidized bed by 5% from the coal softening start temperature which is the upper limit temperature of the coal.
A method for producing coke by rapid heating of coal, comprising heating to a temperature lower than -10 ° C at a heating rate of 90 ° C / min or more and 500 ° C / min or less, followed by dry distillation in a room coke oven.