KR20140049760A - Method for manufacturing coke - Google Patents

Abstract

A method for manufacturing coke, according to the present invention, includes: a step for preparing raw material carbon and tar; a step for combining the raw material carbon and tar; and a step for manufacturing coke by carbonizing the raw material carbon combined with the tar. The contents of tar, proportional to the entire mixture of the raw material carbon and the tar, are below than 3% by weight. In addition, tar is added to the raw material carbon containing micro-viscoelastic carbon, so as to enhance coking properties and charging density, and adjust the viscosity of the tar. Therefore, by using low-cost micro-viscoelastic carbon, high-strength coke can be manufactured. [Reference numerals] (AA) Start; (BB) End; (S100) Preparing raw material carbon and tar; (S200) Preparing the tar; (S300) Mixing the raw material carbon and the tar; (S400) Carbonize the mixture of the raw material carbon and the tar

Description

[0001] The present invention relates to a method for manufacturing coke,

The present invention relates to a coke making method, and more particularly, to a coke making method capable of improving strength.

Coal, that is, coking coal, which is usually used for producing coke, is classified into strong coals and fine coals depending on degree of cohesion. In order to produce coke of high strength, it is advantageous to use strong coals excellent in the degree of cohesion or to use a large amount of strong coals compared with uncoated coals, and thus strong coals have been used in large quantities in the production of coke. However, due to the rapid increase in demand for coking coal for metallurgical use globally and the limited reserves of hard-boiled coals, it has become increasingly difficult to secure strong coals, which has led to a surge in prices. Therefore, although the amount of tin coals to be used must be increased in order to reduce coke manufacturing costs, the quality of the coke is deteriorated due to the lack of the point resistance of the tin coals.

Therefore, there is a demand for a technique for producing a high-quality coke while increasing the amount of tinned coal used.

Korean Patent Laid-Open Publication No. 2001-0015646 discloses a method for producing coke for metallurgy, which uses a blend containing semi-tough coal as a coke oven charging coke.

Korean Patent Publication No. 1997-0042951

The present invention provides a coke making method capable of improving the strength.

Further, the present invention provides a coke making method capable of producing coke of high strength by use of tin-coated carbon.

A method of manufacturing coke according to the present invention includes the steps of preparing coke and tar; Mixing the raw coal and tar; And mixing the raw coke mixed with the tar so as to contain the coke in an amount of not more than 3 wt% based on the total mixture of the coke and the tar.

And a step of crushing the coke in the preparation of the coke, wherein the coke is crushed to a particle size of 10 mm or less.

And crushed so that the particles having a particle size of 3 mm or less are 80% to 90% based on the whole crushed coke.

In the preparation of the coke, the process includes the step of treating the coke so that the water content of the coke is 6 wt% to 10 wt%.

In the preparation of the tar, the viscosity of the tar is set to 50 cP or less.

And adjusting the temperature of the tar to be equal to or higher than 40 ° C in preparing the tar.

It is preferable that the tar is mixed so that the tar is contained in an amount of 1 wt% to 2 wt% based on the entire mixture of the coking coal and the tar.

The coking coal includes unbaked carbon.

The tar mixed with the coking coal is recovered and used in the process of carbonizing the coking coal.

According to the embodiments of the present invention, coal having a low degree of cohesiveness, that is, unbaked coal is used for producing coke. At this time, in the embodiment, tar is added to the coke containing charcoal to improve the toughness and the charging density, and by controlling the viscosity of the tar, cokes of high strength can be produced while using low cost tin coals.

Therefore, it is possible to manufacture coke of high strength while using a large amount of tin coals instead of the tin coals, which are becoming difficult to secure gradually due to the limit of the reserves. Thus, the cost of coke making is reduced and the productivity is improved.

FIG. 1 is a flow chart sequentially illustrating a method of manufacturing a coke according to an embodiment of the present invention.
FIG. 2 is a flowchart sequentially illustrating a method of manufacturing coke according to an embodiment of the present invention. Referring to FIG. 2,
4 is a graph showing charging densities according to the water content and the tar content
5 is a graph showing the hot strength according to the addition amount of tar
6 is a graph showing the cold strength according to the addition amount of tar

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but is capable of other various forms of implementation, and that these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concept of invention to those skilled in the art. It is provided to let you know completely.

1 is a flowchart sequentially illustrating a method of manufacturing a coke according to an embodiment of the present invention. FIG. 2 is a flowchart illustrating a method of preparing coke according to an embodiment of the present invention. Referring to FIG.

Referring to FIG. 1, a method of manufacturing a coke according to an embodiment of the present invention includes the steps of preparing a coke (S100), preparing tar (S200), mixing coke and tar (S300) (S400), charging the mixed mixture into a coke oven, and drying the mixed mixture to produce a coke (S400). Thereafter, the process includes extruding the coke produced from the coke oven, though not separately shown, and digesting the extruded gaseous coke by a wet or nitrogen cooling method

As shown in FIG. 2, the step of preparing the coke (S100) comprises the steps of preparing a coke to be used for producing the coke (S110), crushing the coke (S120) and adjusting the moisture content of the coke (S130). In addition, the process of preparing tar (S100) includes a process of preparing tar (S210) and a process of controlling temperature of tar (S220).

Hereinafter, a method of manufacturing a coke according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 and 2. FIG.

Prior to mixing the raw coal and the tar, a process (S100) for preparing the raw coal and a process (S200) for preparing the tar are performed. The steps (S200, S300) for preparing the coking coal and the tar include the pretreatment processes performed on the coking coal and the tar before the mixing of the coking coal and the tar to produce a high strength coke.

First, a process (S100) of preparing a raw coal is described. In the yard of the workplace, various kinds, for example, 10 to 13 types of coal, that is, coking coal, are loaded for producing coke. Here, the cokes of different species have different compositions or degrees of cohesion, and they are classified into strong coals, which are highly cohesive and coarse coals, which are low cohesion, depending on the degree of cohesion. In addition, according to the embodiment, the content of the tin-free carbon is higher than the content of the tin coals in the mixed carbon.

While several species (or plural species) of coke are loaded on the yard, water is sprinkled on each coke to make the coke contain a predetermined amount of water. Thereafter, each of the raw materials is crushed (S120) so that the particle size is 10 mm, and the particles are crushed so that the fraction of particles having a particle size of 3 mm or less is 80% to 90%. This is to improve the charging density and fluidity of the crushed coke oven when it is charged into the coke oven. For example, when the particle size of the crushed coke is more than 10 mm, the voids between the particles and the particles are too large and the charging density is low when charged into the coke oven, which may cause the fluidity to deteriorate. Therefore, in the embodiment, each coal is crushed to make the particle size of the coal 10 mm or less.

After the crushing of each coke is finished, the coke is heat-treated at a predetermined temperature and dried, and the moisture content is controlled in the drying process (S 130). In the embodiment, moisture is adjusted to 6 wt% to 10 wt% with respect to the coke. Such control of the moisture content is intended to improve the flowability of the cerium particles at the time of adding tar and to reduce the voids of the cerium particles, thereby increasing the charging density. On the other hand, when the content of water is less than 6 wt%, the moisture contained in the raw coal is too small, and there is a problem that the flowability and the charging density of the coal particles are poor at the time of adding the tar. On the other hand, when the content of water exceeds 10 wt%, the flowability is excessively improved, and there is a problem that it is not easy to supply the raw coal to a hopper, a belt, a chute, or the like. Therefore, in the embodiment, the content of water contained in each coking coal is set to 6 wt% to 10 wt%.

When the moisture content of each of the various kinds of coke to be involved in the coke production is controlled through the drying process, the coke is stored in each of the plurality of hoppers. In order to produce coke of a certain quality, the blending ratio of each coal type is calculated, and a certain amount of coking coal is discharged from each hopper on the basis of the blending ratio, and is loaded on the belt. Each of the cokes moves along a belt and is mixed while passing through a chute located on a moving path of the belt. Thus, a mixture of plural kinds of cokes is mixed.

As described above, a mixture of plural kinds of raw coal is referred to as a coal blend, and hereinafter, plural kinds of raw coals are mixed as raw coal for convenience of description.

On the other hand, when the coke oven is dry in the coke oven in the general coke making process, gas (i.e., coke oven gas (COG)), tar and landscape oil are produced due to the carbonization of the coke oven. Among them, more than 90% of the tar produced at the time of carbonitriding is composed of carbon, and most of the tar exists in the form of an aromatic compound. Therefore, when tar is mixed with the raw coal, the wettability of the coarse carbon particles is improved, and the binder acts as a binder contributing to the bonding of the coarse carbon particles due to the chemical structure of the aromatic compound. Further, the pyrolysis of the coke is delayed, and the coke quality is improved by improving the structure arrangement of the produced coke. Accordingly, in the present invention, coke is produced by adding tar to the raw coal.

Hereinafter, the process 200 for preparing tar will be described in detail.

In the step S210 of preparing the tar in the step S200 of preparing the tar in the embodiment, the tar is recovered and liquefied as a by-product generated in the coke oven during the carbonization of the coking oven. The liquefied tar is stored in a separate storage tank, and then the temperature of the tar in the storage tank is adjusted (S220) to maintain a viscosity of 50 cP or less. For example, the outside or inside of the storage tank is heated so that the tar contained in the storage tank is maintained at 40 ° C or higher, thereby maintaining a viscosity of 50 cP or lower. This adjustment of the viscosity is intended to allow the tar to be well mixed on the surface of the raw coal when the tar and coking coal are mixed. For example, when the viscosity of the tar exceeds 50 cP, there is a problem that mixing of tar and coking coal is not easy because the viscosity is too high. Therefore, in the embodiment, the temperature of the tar is kept at 40 DEG C or higher, and the viscosity is maintained at 50 cP or lower.

When the mixed coal and tar mixed with various kinds of raw coal after the crushing and moisture content adjustment process of the coke are prepared, the prepared coke, that is, the combination coal and tar are charged into the mixer and mixed (S300). Here, the mixer may include, for example, a container for containing coke and tar, and a rotatable blade installed to be charged into the container. Thus, when the blade rotates, the coal and tar contained in the container are mixed. Of course, the mixer is not limited to the structure having the above-described blades, and various means capable of mixing the tar and the tar can be used.

The content of tar is more than 0 wt% and not more than 3 wt%, more preferably, 1 wt% to 2 wt% based on the whole mixture of the coking coal and tar at the time of mixing the coking coal and tar. This is because the addition of less than 3wt% of tar improves the fluidity of the coke oven and increases the charging density at the time of charging into the coke oven, the structure of the coke becomes dense, the porosity decreases, and the hot strength and cold strength increase to be.

On the other hand, for example, when tar is not added (0 wt%), there is a problem of low charging density due to low fluidity of coking coal, low density of coke, high porosity and low hot strength and cold strength. On the other hand, when the content of tar is more than 3 wt%, the effect of adding tar is not large and the tar is unnecessarily consumed. Therefore, in the embodiment, the content of tar is made to be 3 wt% or less based on the whole mixture of coking coal and tar.

When tar and coking coal are mixed in this way, the mixture is charged into a coal bin, a certain amount of mixture is discharged from the coalbin as a charge, and charged into the coke oven. Thereafter, the mixture is dried in a coke oven to produce a coke, and the coke produced is extruded. The extruded coke is extinguished by wet or nitrogen cooling.

Table 1 is a table showing the degree of flow of the blend according to the first to third comparative examples and the first to third embodiments. Here, the first to third comparative examples are cases where tar is not used as an additive in the blend, and the first to third examples are cases where tar is blended in the blend. Here, in the first to third embodiments, the content of tar is 3 wt% with respect to the whole mixture in which the blend coal and tar are mixed. As described above, the compounded carbon is a mixture of plural types of cyanogen, and the first cyan, the second cyan, and the third cyan are mixed with each other and the mixing ratios are different from each other. As described above, each of the first to third compounded coals is mixed with a plurality of kinds of coking coal, and the content of the untreated carbon is higher than the content of the strong carbon.

Flow starting temperature (GST) [캜] Maximum flow temperature (MFT)
[° C] Maximum Flow (MF)
[cP] The logarithm of maximum flow (L_MF) The solidification starting temperature (SLT)
[° C]
Flow temperature range (GR)
[° C]
First Comparative Example
: First compounding tar + tar 0 wt% 425 458 9 0.95 497 54 First embodiment
: 1st blend + tar 3 wt% 417 459 15 1.18 483 66 2nd comparative example
: The second blend + tar 0 wt% 418 457 18 1.26 481 63 Second embodiment
: The second combination tar + tar 3 wt% 108 453 42 1.62 480 72 Comparative Example 3
: Third compound tar + tar 0 wt% 428 455 3 0.48 473 445 Third Embodiment
: Third blend + tar 3 wt% 413 453 24 1.34 480 68

Referring to Table 1, the maximum degree of flow (MF) is higher than that of the blended carbon (first to third comparative examples) when tar is added to the blend (Examples 1 to 3) The flow temperature range (GR) is also wide. From this, it can be seen that the addition of tar to the blend enhances the integrity of the blend. The improvement in the degree of cohesion has the effect of enhancing the strength because the properties of the coking coal, i.e., coal, are enhanced.

3 is a graph showing the viscosity of tar according to temperature.

In order to add tar to the coke to allow the tar to mix well with the surface of the coke, the viscosity of the tar is an important factor. If the viscosity of the tar is too high, it is not easy to mix the tar and tar. Referring to FIG. 3, as the temperature of the tar increases, the viscosity decreases. When the temperature of the tar is 30 ° C or less, the viscosity is as high as 150 cP or more. Especially, when the temperature of the tar is 20 ° C, the viscosity is as high as about 800 cP. When the temperature of the tar is 40 ° C or higher, the viscosity is maintained at 50 cP or lower. In order for tar and coke to be easily mixed, it is effective that the viscosity of the tar is 50 cP or less. As shown in FIG. 3, as the temperature of the tar increases to a temperature of 40 ° C or higher, the viscosity decreases, but the slope of the decrease is low. When the temperature is higher than 90 ° C, It can be predicted that there will be little difference in viscosity. Accordingly, in the present invention, the temperature of the tar is controlled to be 40 ° C or higher, and more preferably, the temperature of the tar is controlled to be 40 ° C to 90 ° C or less in order to reduce unnecessary power consumption. Such temperature control of the tar can be controlled by heating the storage tank in which the tar is stored.

4 is a graph showing charging densities depending on the water content and the tar content.

Referring to FIG. 4, the charging density increases as the amount of additive tar increases with respect to 6 wt% of moisture content and 10 wt% moisture content.

This is because the flow ability of the raw coal particles was improved due to the addition of tar, and the voids between the raw coal particles were reduced. However, when the water content is 2 wt%, the effect of increasing the loading density according to the tar addition amount is insignificant. This is because the water content of the raw coal itself is too low and the flowability of the coal particles is low. Therefore, in the embodiment of the present invention, the content of water contained in the coke is set to 6 to 10 wt%. Therefore, the charging density of the coking coal is improved, thereby improving the strength. As described above, the control of the moisture content can be controlled through the drying process through heat treatment after crushing the water-loaded coal loaded on the yard.

FIG. 5 is a graph showing the hot strength according to the addition amount of tar, and is shown when the moisture content is 2 wt%, 6 wt%, and 10 wt%, respectively. The hot strength was measured by reacting 200 g of a 20 mm coke sample at 1100 캜 for 2 hours in a CO ₂ atmosphere, rotating the drum 600 times, and then measuring the coke weight ratio of 10 mm or more.

Referring to FIG. 5, as the amount of added tar increases, the hot strength of the coke increases linearly. This is because the added tar is pyrolyzed and discharged to gas and tar, the texture of the coke becomes dense, the porosity is lowered, and the carbon dioxide (CO ₂ ) reactivity decreases after coking.

FIG. 6 is a graph showing the cold strength according to the addition amount of tar, and is shown when the moisture content is 2 wt%, 6 wt%, and 10 wt%, respectively. The cold strength was measured in a coke weight ratio of 15 mm or more after rotating 10 kg of coke 150 times in a drum of 1.5 m diameter.

Referring to FIG. 6, it can be seen that the coke cold strength linearly increases as the amount of tar added increases. This is because, by adding tar, the degree of flow of the raw coal is improved and the charging density is increased. However, in the range where the addition amount of tar is 2 wt% or more, the improvement effect of the cold strength according to the increase of the amount of added tar is less than the range of 1 wt% to 2 wt%. Therefore, in the embodiment of the present invention, the added amount of tar added to the coke is 3 wt% or less, more preferably 1 wt% to 2 wt%.

In the above description, blending is carried out by blending tannin and tannic coals in blended tannins and blending tannin coarser tannin with a content higher than that of tannic coals. However, the coke production method according to an embodiment of the present invention may be applied to using only coking coal or using only coking coal.

As described above, in the present invention, coal having a low degree of cohesion, that is, untreated carbon is used for the production of coke. In this embodiment, tar is added to the tin-free coal to improve the toughness and charging density, and the viscosity of the tar is controlled to be 50 cPP or less, so that a cokes of high strength can be produced while using low cost tin coals. Therefore, it is possible to manufacture coke of high strength while using unripe coal instead of strong carbon which is gradually getting harder due to the limit of reserves. Thus, the cost of coke making is reduced and the productivity is improved.

S100: Preparation of raw coal S200: Preparation of tar
S300: Mixture of coking coal and tar

Claims (9)

The process of preparing coking coal and tar;
Mixing the raw coal and tar;
And carbonizing the raw coke mixed with the tar to produce a coke,
Based on the entire mixture of the raw coal and the tar, the coke production method for mixing so that the tar is contained in 3wt% or less. The method according to claim 1,
In the preparation of the coke,
And crushing the raw coke to obtain a coke having a particle size of 10 mm or less. The method according to claim 2,
And crushing the crushed coke so that particles having a particle size of 3 mm or less are 80% to 90% based on the whole crushed coke. The method according to claim 1,
In the preparation of the coke,
Coke manufacturing method comprising the step of treating so that the moisture content contained in the raw coal is 6wt% to 10wt%. The method according to claim 1,
In the process of preparing the tar,
The coke production method to make the viscosity of the tar is 50 cP or less. The method of claim 5,
In the process of preparing the tar,
And adjusting the temperature of the tar to be 40 ° C or higher. The method according to claim 1,
Based on the entire mixture of the raw coal and tar, the coke production method for mixing so that the tar is contained 1wt% to 2wt%. The method according to any one of claims 1 to 7,
Wherein the raw coke contains untreated carbon. The method according to any one of claims 1 to 7,
The coke production method for recovering and using the tar generated in the process of carbonizing the raw coal with the tar mixed with the raw coal.

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