JP2013107930A - Method for producing coke - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing coke that can improve filling density of coal charged into a coke oven without providing new facility.SOLUTION: There is provided a method for producing coke by carbonizing coal in the coke oven, in which powder for improving slipperiness of coal within a range of 5 wt.% or less is added to coal for carbonizing.

Description

  The present invention relates to a coke production method for producing coke by dry distillation of coal in a coke oven.

  Conventionally, it is known that coke strength is improved by improving the packing density of coal charged in a coke oven. Examples of such methods include an oil addition method, a pulverization control method, a coal humidity conditioning method, a preheated coal charging method, a pulverized coal agglomeration method, a molded coal charging method, and a stamping method.

  Patent Document 1 discloses a coke production method in which a bulk density improver adjusted to a viscosity of 10 to 45 mPa · s is added to raw coal for coke production. In the coke manufacturing method of patent document 1, the chemical | medical agent which has surface active effect | action is employ | adopted as a bulk density improvement agent, and it is made to disperse | distribute to the raw coal surface by spraying.

  Patent Document 2 discloses a method for producing coke, in which after adding a bulk density improver to coal, the humidity is adjusted, and the conditioned coal is charged into a coke oven. In Patent Document 2, a solution in which a surfactant is dissolved in a solvent is used as a bulk density improver, and this is added to coal, thereby reducing the surface tension of water attached to the coal surface and utilizing lubricity. This increases the bulk density of the charged coal.

JP 2007-63420 A JP 2010-77332 A

  However, the pulverization control method may cause generation of fine particles due to pulverization, which is not preferable in terms of environment. In addition, it is necessary to determine an appropriate pulverization degree in advance according to the properties of the coal, and when the pulverization is not performed properly, there is a problem that the strength of the coke produced is lowered.

  Also, the coal humidity control method is not environmentally friendly because dust generation becomes prominent when moisture decreases. In addition, there is a problem in that a lower limit value of moisture is set and dust countermeasure equipment is required.

  Moreover, the preheating charcoal charging method is handled at a high temperature of about 300 ° C. Therefore, in order to prevent ignition and oxidation / deterioration of coal, the atmosphere must be a nitrogen atmosphere, and nitrogen is required. Moreover, since there is little water | moisture content of coal, there exists a problem that the fine powder at the time of coke oven charging is accompanied with generated gas, enters into tar, and tar quality is inhibited. Further, the expansion pressure becomes high during dry distillation, which may cause damage to the coke oven wall.

  In the pulverized coal agglomeration method, fine powder and coarse powder are dried and separated, and the fine powder is agglomerated. However, if the agglomeration strength is insufficient, the agglomeration breaks in the middle, and There is a problem that dust is generated. Also, when dust accumulates, there is a risk of spontaneous ignition due to low moisture.

  Moreover, the molding charcoal charging method requires a binder for molding. In addition, there is a problem that the uneven distribution of the molded product at the time of charging is large.

  In addition, because the stamping method charges the molded cake into the coke oven, there is a problem that the clearance with the furnace wall expands freely and there is a local deterioration in quality. There's a problem.

  In addition, the above-described pulverization control method, coal humidity conditioning method, preheating coal charging method, pulverized coal agglomeration method, molded coal charging method, and stamping method are all performed before charging coal into a coke oven. It is a large scale and requires special equipment.

  In addition, since the bulk density improver and the oil addition method disclosed in Patent Document 1 and Patent Document 2 are in a solution state, facilities such as spraying the bulk density improver on a conventional production line, It is necessary to install new odor control equipment.

  This invention is made | formed in view of the subject mentioned above, The objective is the manufacturing method of the coke which can improve the packing density of the coal charged into a coke oven, without providing a new installation. It is to provide.

  The coke production method according to the present invention is a coke production method for producing coke by dry distillation of coal in a coke oven, and the powder for improving the slipperiness of coal is in the range of 5% by weight or less. It is characterized by being added to coal and dry distillation.

  According to the said structure, the powder for improving the slipperiness | lubricity of coal is added to coal. Therefore, the packing density of the coal charged into the coke oven can be improved. As a result, it is possible to increase the amount of coke that can be carbonized by a coke oven having a constant volume, and to improve coke productivity. Moreover, by adding the powder for improving the slipperiness of coal to the coal within a range of 5% by weight or less, the packing density of coal can be improved and the coke strength can be improved. Moreover, since powder (powder for improving the slipperiness of coal) is added to coal, conventional production equipment (for example, a mixing tank) is provided without providing new equipment (for example, a spraying line). You just have to charge it. Therefore, it is possible to improve the packing density of the coal charged into the coke oven without providing new equipment.

  The said structure WHEREIN: It is preferable that the powder for improving the said slipperiness is graphite. When the powder for improving the slipperiness is graphite, since graphite is a carbon substance having a high carbon content, it can act as a reducing agent that plays the role of metallurgical coke. Further, since the volatile matter is low, the coke yield can be improved.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the coke which can improve the packing density of the coal charged into a coke oven can be provided, without providing new equipment.

It is a block diagram which shows the outline | summary of the coke manufacturing equipment which concerns on this embodiment. It is sectional drawing which shows an example of a packing density measuring apparatus typically. It is a graph which shows the improvement amount of a packing density. It is a graph which shows the relationship between graphite addition amount and drum strength index (DI).

Hereinafter, the manufacturing method of the coke which concerns on this embodiment is demonstrated. FIG. 1 is a block diagram for explaining an outline of a coke production facility according to the present embodiment.
The coke production facility 10 includes a blending tank 12, a pulverizer 14, a humidity controller 16, and a coke oven 18. In the blending tank 12, a plurality of types of brand coal are blended. In the present embodiment, a powder 20 (hereinafter also referred to as powder 20) for improving the slipperiness of coal is charged into the blending tank 12.

  The coal and the powder 20 blended in the blending tank 12 are sent to the pulverizer 14 and pulverized so as to have an appropriate particle size according to the properties of the coal. Next, the moisture of the coal sent to the humidity controller 16 and pulverized is adjusted. The coal whose moisture has been adjusted by the humidity controller 16 is then charged into the coke oven 18. In the coke oven 18, the coal is carbonized to become coke.

  In the present invention, the powder for improving the slipperiness of coal refers to a powder that can improve the slipperiness of coal by adding to the coal, and a sample in which the powder is added to coal is used. The powder in which the packing density calculated by the following method 1 is higher than that of the sample to which the powder is not added. In other words, this powder is a powder having such a property that the filling density can be increased by adding a specific powder to the coal, compared to the case of filling only a coal in a container having a constant volume. Since the powder itself is hard to get wet and is slippery as a smooth powder, and when added to coal, the powder is easily slipped between the coal particles, so that the slipperiness of the coal can be improved.

(Method 1)
FIG. 2 is a cross-sectional view schematically showing an example of a packing density measuring apparatus.
As shown in FIG. 2, the filling density measuring device 40 includes a hollow body 42 having a cavity of 90 mm in width and 250 mm in length (depth in FIG. 2), a sample hopper 44 provided on the top of the hollow body 42, and a hollow A stopper 46 is provided between the body 42 and the sample hopper 44. The stopper 46 is provided at a position having a height of 1317 mm from the lowermost part of the hollow body, and the sample in the sample hopper 44 can be dropped into the hollow body 42 or stopped.
First, a powder of 7.5 kg in total weight (in the case of including moisture or the like, the weight including moisture or the like) is charged in the sample hopper 44 of the packing density measuring device 40. Next, the sample hopper 44 is pushed in and the powder is dropped. Next, the height (powder filling height) of the dropped powder (deposit) is measured. Next, the powder weight of the dropped powder (deposit) is weighed, and the weighed powder is reduced to measure moisture. After the moisture measurement, the packing density (dry base) is calculated using the following formula 1.

BD (db): Packing density (kg / m ³ )
Powder weight: kg
Powder moisture:% by weight of moisture relative to powder
Device width: m (ie, 0.09 m)
Device length: m (ie, 0.25 m)
Powder filling height: m

  The powder 20 is not particularly limited as long as the packing density calculated by the above (Method 1) is a powder that can increase the packing density by adding to the coal than when only the coal is packed, Examples thereof include graphite, cosmetic raw materials (for example, cyclopentasiloxane), Teflon (registered trademark) powder, fluorine powder, and the like. These substances include those generally used as powder lubricants. Among these, graphite is preferable from the viewpoint of improving the coke yield. The reason why the powder 20 can improve the slipperiness of the coal is that the powder 20 adheres to the coal surface due to moisture on the coal surface, and the slipperiness of the coal depends on the powder 20, thereby causing the slipperiness of the coal. Is estimated to improve.

  In general, it is known that the coke strength is improved when the charging density of coal is improved (see, for example, Steel Handbook, Third Edition, II, Steelmaking / Steelmaking, 170). Therefore, the use of coal with improved packing density improves the coke strength.

  The amount of coal moisture adjusted in the factory having the humidity controller 16 in the coke production process or the amount of coal moisture in the factory not having the humidity controller is generally 6 to 10% by weight based on coal. The present invention is more preferably applied to 7 to 8.5%. By making this moisture content into the said numerical range, the improvement of the packing density of coal can be enlarged more.

  The addition amount of the powder 20 is 5 wt% or less with respect to coal, and preferably 3 wt% or less. By making the addition amount of the powder 20 with respect to coal 5 wt% or less, the coke strength of the produced coke can be improved. More specifically, in the coke production, normally, when the raw coal is heated, it exhibits a softening and melting phenomenon. In particular, graphite does not exhibit a softening and melting phenomenon. Here, when coke is produced, it is generally known that coke strength decreases when an object that is not softened and melted is added to coal that is softened and melted and subjected to dry distillation. On the other hand, coke strength increases when the coal packing density is increased and dry distillation is performed. The present invention has intensively studied the relationship between the reduction in coke strength due to the addition of powder and the improvement in the packing density of coal due to the addition of powder. It is the invention which has been found out that the coke strength of the produced coke can be improved by adjusting the content to less than or equal to% by weight.

  As mentioned above, according to the manufacturing method of the coke which concerns on this embodiment, the powder 20 for improving the slipperiness | lubricity of coal is added to coal. Therefore, the packing density of the coal charged into the coke oven 18 can be improved. The amount of coke obtained by dry distillation in a coke oven having a constant volume can be increased, and the productivity of coke can be improved. Moreover, since the packing density of coal can be improved by adding the powder 20 for improving the slipperiness of coal to coal, coke intensity | strength can be improved. Furthermore, since the powder (powder 20 for improving the slipperiness of coal) is added to the coal, the conventional production equipment (in this embodiment, the blending tank 12) is directly installed without providing new equipment. Just enter. Therefore, the packing density of the coal charged into the coke oven 18 can be improved without providing new equipment.

  In the above-described embodiment, the case where the powder 20 is charged into the blending tank 12 has been described. However, in the present invention, the timing of adding the powder for improving the slipperiness to the coal is not limited to the above example, and the coal is fed before and after the pulverizer in the transporting process until the coal is charged into the coke oven. It may be added to or before or after the humidity controller. That is, in the present invention, the powder for improving the slipperiness of coal may be added to the coal before being charged into the coke oven. In the present invention, the powder for improving the slipperiness of coal may be added and charged at the same time when coal is charged into a coke oven. This is because the powder according to the present invention is added between the coal particles. If the powder for improving the slipperiness of coal is added before the coal is charged into the coke oven, or added when charging into the coke oven, the slipperiness of the coal can be improved. A large amount of coal can be charged in a coke oven having a constant volume, and the weight of coke obtained by dry distillation can be increased. Moreover, if the powder for improving the slipperiness of coal is added before charging the coal into the coke oven, or added when charging into the coke oven, the coal packing density can be improved. Therefore, the coke strength can be improved.

  Although embodiment mentioned above demonstrated the case where the coke manufacturing equipment 10 was equipped with the mixing tank 12, the grinder 14, the humidity controller 16, and the coke oven 18, coke manufacturing equipment is not limited to this example and is conventionally well-known. Can be adopted. That is, in the present invention, with respect to the conventionally known coke production equipment, without providing new equipment, a powder for improving the slipperiness of coal can be added to the coal and dry-distilled, There is no particular limitation.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail using an Example, this invention is not limited to a following example, unless the summary is exceeded.

<Evaluation of packing density>
Example 1
3% by weight of graphite as a powder for improving the slipperiness of coal was added to coal as a sample, and mixed for 5 minutes using a V-type blender. Next, pure water was added so that it might become 7.5 weight% with respect to coal for water | moisture content adjustment, and also it mixed for 15 minutes using the V-type blender. The adjusted blended coal was charged into the sample hopper 44 of the packing density measuring device 40 described with reference to FIG. The filling amount was 7.5 kg of total weight (in the case of including powder and moisture for improving the slipping property of coal and coal, the weight including moisture and the like). Next, the sample hopper 44 was pushed in to drop the blended coal. Next, the height (blended coal filling height) of the dropped blended coal (sediment) was measured. Next, the blended coal weight of the dropped blended coal (sediment) was weighed, and the blended coal after weighing was reduced to measure the moisture. After moisture measurement, the packing density (dry base) was calculated using the following formula 2.

BD (db): Packing density (kg / m ³ )
Blended coal weight: kg
Blended coal moisture:% by weight of moisture relative to blended coal
Device width: m (ie, 0.09 m)
Device length: m (ie, 0.25 m)
Charcoal filling height: m

(Example 2)
In order to adjust the water content, the packing density (dry base) was calculated in the same manner as in Example 1 except that pure water was added to 8.5% by weight with respect to coal.

  FIG. 3 is a graph showing the amount of improvement in packing density. In FIG. 3, ΔBD (d.b) represents the difference between the packing density of the graphite-blended coal and the packing density of the graphite-free coal.

(result)
By adding graphite, the packing density of coal could be improved. The improvement effect was greater when the amount of moisture was 7.5% by weight than when 8.5% by weight of coal.

<Evaluation of coke strength>
(Example 3)
3% by weight of graphite as a powder for improving the slipperiness of coal was added to coal as a sample, and mixed for 5 minutes using a V-type blender. Next, pure water was added so that it might become 7.5 weight% with respect to coal for water | moisture content adjustment, and also it mixed for 15 minutes using the V-type blender. The adjusted blended coal was charged into the sample hopper 44 of the packing density measuring device 40 described with reference to FIG. The filling amount was 7.5 kg of total weight (in the case of including powder and moisture for improving the slipping property of coal and coal, the weight including moisture and the like). Next, the sample hopper 44 was pushed in to drop the blended coal. Next, the height (blended coal filling height) of the dropped blended coal (sediment) was measured. Next, the blended coal weight of the dropped blended coal (sediment) was weighed, and the blended coal after weighing was reduced to measure the moisture. After the moisture measurement, the packing density (dry base) was calculated using Equation 2 above. The results are shown in Table 1.

(Comparative Example 1)
A sample was prepared in the same manner as in Example 3 except that the powder for improving the slipperiness of coal was not added. Thereafter, the packing density (dry base) was calculated in the same manner as in Example 3. The results are shown in Table 1.

(Comparative Example 2)
A sample was prepared in the same manner as in Example 3 except that the amount of powder added to improve the slipperiness of coal was 10% by weight. Thereafter, the packing density (dry base) was calculated in the same manner as in Example 3. ΔBD (db) represents the difference between the packing density of the graphite-blended coal and the packing density of the graphite-free coal. The results are shown in Table 1.

  The samples prepared in Example 3 and Comparative Examples 1 and 2 were heated until the coal core temperature reached 1000 ° C., and then cooled with suffocation to produce coke. Next, for the obtained coke, a drum strength index (DI) as coke strength was determined in accordance with JIS K 2151. The drum strength index was measured twice and the average value was obtained. FIG. 4 is a graph showing the relationship between the graphite addition amount and the drum strength index (DI). In FIG. 4, the drum strength index uses an average value of two measurements.

(result)
In Example 3 in which the amount of graphite added was 3% by weight with respect to coal, the drum strength index (DI) was improved as compared with the case of no addition (Comparative Example 1). Further, in Comparative Example 2 in which the amount of graphite added was 10% by weight with respect to coal, the drum strength index (DI) was lower than when 3% by weight was added or when not added.

Claims (2)

A coke production method for producing coke by carbonizing coal in a coke oven,
A method for producing coke, characterized in that a powder for improving the slipperiness of coal is added to the coal within a range of 5% by weight or less and subjected to dry distillation. The method for producing coke according to claim 1, wherein the powder for improving the slipperiness is graphite.