KR102439332B1 - Coal briquette composition, coal briquette comprising the same and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a coal briquette composition comprising pulverized coal and a binder, wherein the binder comprises cellulose ether and raw starch that do not gel at 50 to 97° C. . According to the present invention, since cellulose ether is not thermally gelled during the gelatinization process of raw starch requiring high temperature conditions, a manufacturing process of mixing the binder and pulverized coal under high temperature conditions and then molding can be performed, and as a result, drop strength and It is possible to provide coal briquettes having excellent compressive strength.

Description

Coal briquette composition, coal briquette comprising same, and method for manufacturing the same {Coal briquette composition, coal briquette comprising the same and manufacturing method thereof}

The present invention relates to a coal briquette composition, to a coal briquette comprising the same, and a method for manufacturing the same, and more particularly, to a coal briquette having excellent drop strength and compressive strength by including cellulose ether and raw starch that do not gel at 50 to 97° C. It relates to a coal briquette composition that can be made, a coal briquette containing the same, and a method for manufacturing the same.

In general, coal is used as a heat source in various fields such as thermal power plants, steel mills, small-scale households, agricultural or industrial heating boilers. However, when the coal is pulverized coal of 8 mm or less, its use is limited due to insufficient combustion and dust generation. Therefore, the low-grade pulverized coal having a particle size of 8 mm or less, particularly 4 mm or less, is used after being processed into coal briquettes of a certain particle size.

When processing low-grade pulverized coal having a small particle size into coal briquettes as described above, molasses has been mainly used as a binder in the prior art. For example, in Patent Document 1 (Republic of Korea Patent Publication No. 10-0568337), a step of first mixing molasses as a binder with pulverized coal, a second mixing of slaked lime as a curing agent in a mixture of pulverized coal and molasses, and the second mixture A method of manufacturing coal briquettes comprising the step of molding into coal briquettes is described.

However, molasses has several problems, such as supply and demand, quality instability, and odor due to harvesting, and thus the development of an alternative binder was required, and cellulose ether or starch was suggested as an alternative binder.

As such a conventional method, Patent Document 2 (Korean Patent Application Laid-Open No. 10-2016-0010316) is one selected from the group consisting of alkyl cellulose, hydroxyalkyl cellulose and hydroxyalkylalkyl cellulose having a viscosity of 1,000 to 80,000 cps. It describes a binder for coal briquettes containing more than one type of cellulose ether-based compound, and Patent Document 3 (Korean Patent Publication No. 10-2017-0068327) discloses a binder mixture prepared by mixing starch, lignin, aqueous acid solution and water. It describes a method for producing pulverized coal into coal briquettes using

As a binder for manufacturing pulverized coal into coal briquettes as described in the prior literature, cellulose ether or starch may be individually applied to each, but when the two are mixed, coal briquettes having better strength can be manufactured. However, starch, for example, raw starch, is gelatinized under high temperature conditions while maximizing viscosity while gelatinizing under high temperature conditions, thereby reducing adhesive strength. That is, since the temperature conditions for maximally expressing the adhesive strength of cellulose ether and raw starch are different, it was difficult to express the strength of the final coal briquettes to the maximum by mixing raw starch and cellulose ether.

Accordingly, it is necessary to study a method for providing high-strength coal briquettes by mixing cellulose ether and raw starch as a binder for the coal briquettes, but providing a composition for gelatinization of cellulose ether that is capable of gelatinization of raw starch and gelatinization of raw starch under high temperature conditions. .

US 100568337 B US 102016010316 A US 1020170068327 A

An object of the present invention is to provide a coal briquette composition capable of manufacturing coal briquettes having excellent drop strength and compressive strength by including cellulose ether and raw starch that do not gel at 50 to 97°C as binders.

In addition, the present invention is to provide a coal briquette comprising the composition and a method for manufacturing the same.

In order to solve the above problems, the present invention provides a coal briquette composition comprising pulverized coal and a binder, wherein the binder does not gel at 50 to 97° C. and cellulose ether and raw starch.

The gelation temperature of the cellulose ether may be higher than that of the raw starch.

The cellulose ether is at least one selected from the group consisting of alkyl cellulose, hydroxyalkyl cellulose, hydroxyalkyl alkyl cellulose, and alkyl alkyl hydroxylalkyl cellulose. It may include, and preferably has a hydroxyethyl substitution degree (MS) of 0.8 or more and 4.0 or less of hydroxyethyl cellulose (HEC); hydroxyethyl methyl cellulose (HEMC) having a methyl substitution degree (DS) of greater than 0 and 1.3 and a hydroxyethyl substitution degree (MS) of 0.8 or more and 4.0 or less; and hydroxypropyl methyl cellulose (HPMC) having a methyl substitution degree (DS) of more than 0 and 1.0 or less and a hydroxypropyl substitution degree (MS) of 0.1 or more and 0.25 or less; may include at least one selected from the group consisting of have.

Based on 100 parts by weight of the pulverized coal, the content of the cellulose ether may be 0.1 to 1.0 parts by weight, and the content of the raw starch may be 0.1 to 5.0 parts by weight.

And, the coal briquette composition according to the present invention may further include water. In this case, the water may be included in the form of hot water or steam having a temperature between the gelation temperature of the raw starch and the gelation temperature of the cellulose ether.

In addition, the present invention provides a coal briquette comprising the coal briquette composition and a method for manufacturing the same, the manufacturing method comprising the steps of: (1) providing pulverized coal; (2) adding cellulose ether and raw starch that do not gel at 50 to 97° C. into the pulverized coal, followed by dry mixing; (3) wet mixing the dry mixture obtained in step (2) under a temperature environment between the gelation temperature of the raw starch and the gelation temperature of cellulose ether; (4) mixing the wet mixture obtained in step (3) under a high temperature environment having a temperature higher than that of step (3); and (5) molding the mixture obtained according to step (4) to provide coal briquettes.

Step (3) may be performed by injecting hot water having a temperature between the gelation temperature of the raw starch and the gelation temperature of cellulose ether or spraying steam. At this time, the temperature range of the high temperature water may be 90 ~ 100 ℃.

Step (4) may be performed for 5 to 40 minutes under a high temperature environment of 100 to 150 ℃.

According to the present invention, cellulose ether and raw starch are mixed as a binder for coal briquettes, but cellulose ether that does not gel at the gelatinization temperature range of the raw starch, specifically 50 to 97°C, is used as a binder for raw starch gelatinization requiring high temperature conditions. It is possible to suppress thermal gelation of a viscous cellulose ether aqueous solution while proceeding.

Accordingly, it is possible to perform a manufacturing process of mixing the binder and pulverized coal under high temperature conditions and then molding, and as a result, it is possible to provide coal briquettes having excellent drop strength and compressive strength.

Hereinafter, the present invention will be described in detail so that those of ordinary skill in the art can easily carry out the present invention.

The present invention relates to a coal briquette composition comprising pulverized coal and a binder, a coal briquette comprising the same, and a method for manufacturing the same, wherein the binder includes cellulose ether and raw starch that do not gel at 50 to 97°C.

As used herein, "pulverized coal" refers to coal having a particle size of 8 mm or less. In order to reduce variations in the quality of the coal briquettes, it is preferable that the particle size of the pulverized coal is small and constant, for example, pulverized coal having a particle size of greater than 0 mm and less than or equal to 4 mm may be preferably used. In general, the coal is divided into about 60% peat, about 70% peat and lignite, about 70% to 80% sub-bituminous coal, about 80% to 90% bituminous coal, and 90% or more anthracite according to the degree of carbonization. do. The type of coal used in the present invention is not particularly limited, and a single coal type or a mixture of various types of coal may be used.

The binder is for manufacturing coal briquettes by binding the pulverized coal, and serves to bind the pulverized coal particles to each other. In the present invention, cellulose ether and raw starch that do not gel at 50 to 97° C. are mixed.

Looking at the principle of expression of the adhesive force of the binder, raw starch is gelatinized under high temperature conditions and the viscosity is maximized to express the maximum adhesive force. On the other hand, the cellulose ether expresses adhesive force through dissolution. Specifically, the cellulose ether is dissolved in a polar solvent represented by water, and in this process, the hydrophilic group contained in the cellulose ether forms a hydrogen bond with the water molecule and the viscosity is expressed, and then the adhesive force is expressed through the process of evaporating the moisture. .

However, in the case of a cellulose ether substituted with a hydrophobic group, there is a property that the activity of the hydrophobic group is increased under a high temperature condition of a specific temperature or more. When hot water or steam above a certain temperature is used as a solvent in the dissolution process for the viscosity expression of the cellulose ether, the activity of the hydrophobic group is higher than the hydrogen bonding between the hydrophilic group and the water molecule. Accordingly, as the hydrogen bond formed in the dissolution process of the cellulose ether is broken, a thermal gelation phenomenon in which the cellulose ether is re-precipitated from the cellulose ether aqueous solution may be caused, and thus the viscosity in the solution state may be lost. At this time, the temperature is referred to as a gelation temperature (gel point).

That is, raw starch is essential to high-temperature conditions required for gelatinization in order to express excellent adhesion, and accordingly, when high-temperature conditions are applied, there is a problem in that the cellulose ether is thermally gelled. Accordingly, the inventors of the present inventors have repeatedly studied to prepare coal briquettes having excellent strength by mixing cellulose ether and raw starch as a binder, and as a result, it was confirmed that it is necessary to control the gelation temperature of the cellulose ether.

Specifically, in the present invention, cellulose ether that does not gel at 50 to 97° C. including the gelatinization temperature range of raw starch is used. At this time, since the cellulose ether does not gel at less than 50 ° C., the cellulose ether that does not gel at 50 to 97 ° C. does not gel at the entire temperature range below 97 ° C. That is, "cellulose ether that does not gel at 50 to 97° C." used in the present invention is equivalent to "cellulose ether having a gelation temperature of at least 97° C.".

Preferably, the gelation temperature of the cellulose ether may be higher than that of the raw starch. In this way, when cellulose ether having a gelation temperature higher than the gelation temperature is mixed with raw starch and used as a binder for coal briquettes, gelatinization of the cellulose ether viscous solution can be suppressed at the same time while gelatinization of raw starch is progressed. It is possible to provide coal briquettes having drop and compressive strength.

The cellulose ether is derived from cellulose, a vegetable material, and is a kind of cellulose derivative in which a hydroxyl group of cellulose is etherified using an etherification agent. Specifically, the cellulose ether is alkyl cellulose (alkyl cellulose), hydroxyalkyl cellulose (hydroxyalkyl cellulose), hydroxyalkyl alkyl cellulose (hydroxyalkyl alkyl cellulose) and alkylalkyl hydroxyalkyl cellulose (alkyl alkyl hydroxylalkyl cellulose) from the group consisting of It may include at least one selected ; HEMC), hydroxypropyl methyl cellulose (HPMC), ethyl hydroxyethyl cellulose (EHEC), and a type selected from the group consisting of methylethyl hydroxyethyl cellulose (MEHEC) More than one can be used.

Preferably, the cellulose ether is hydroxyethyl cellulose (hydroxyethyl cellulose; HEC) having a hydroxyethyl substitution degree (MS) of 0.8 or more and 4.0 or less; hydroxyethyl methyl cellulose (HEMC) having a methyl substitution degree (DS) of greater than 0 and 1.3 and a hydroxyethyl substitution degree (MS) of 0.8 or more and 4.0 or less; and hydroxypropyl methyl cellulose (HPMC) having a methyl substitution degree (DS) of more than 0 and 1.0 or less and a hydroxypropyl substitution degree (MS) of 0.1 or more and 0.25 or less; may include at least one selected from the group consisting of have. The degree of substitution affects the gelation temperature of the cellulose ether, and when DS and MS are each included in the above range, it is possible to provide a cellulose ether that does not gel at 97° C. or less, and as a result, coal briquettes having excellent drop strength and compressive strength It is preferable to be able to manufacture Here, the term "degree of substitution" refers to the average number of hydroxyl groups substituted with an alkyl group or a hydroxyalkyl group per unit of anhydroglucose.

The raw starch may be at least one selected from the group consisting of rice starch, wheat starch, barley starch, corn starch, potato starch, sweet potato starch, cassava starch, and tapioca starch. The raw starch is usually referred to as β-starch, and exhibits a fine crystalline state with a regular molecular arrangement. On the other hand, pregelatinized starch is called α-starch, and exhibits an amorphous state with irregular molecular arrangement. A phenomenon in which the β-starch is changed to α-starch is called gelatinization, and as described above, the raw starch is gelatinized under high-temperature conditions to maximize its viscosity, and in this process, it has the maximum adhesive strength. On the other hand, the gelatinized starch is starch in which the gelatinization process has been completed, that is, starch that has passed the time point at which maximum viscosity is expressed. Therefore, the gelatinized starch has a lower viscosity than the gelatinization point of raw starch. That is, when raw starch is applied to pulverized coal according to the present invention to express adhesive strength while gelatinizing, rather than using gelatinized starch as a binder, coal briquettes having remarkably high strength can be provided.

Based on 100 parts by weight of the pulverized coal, the content of the cellulose ether may be 0.1 to 1.0 parts by weight, and the content of the raw starch may be 0.1 to 5.0 parts by weight. When the content of the cellulose ether and raw starch is included within the above range, it is preferable to obtain high-strength coal briquettes even with a small amount of addition.

The coal briquette composition according to the present invention may further include water, and the water may be included in the form of hot water or steam having a temperature between the gelation temperature of the raw starch and the gelation temperature of cellulose ether. In this case, as the high-temperature water, distilled water having a temperature between the gelation temperature of the raw starch and the gelation temperature of the cellulose ether may be used, and preferably, distilled water having a temperature of 90 to 100° C. may be used. The high-temperature water may be included within 50.0 parts by weight based on 100 parts by weight of the coal. When the content of the high temperature water is within the above range, it is possible to obtain a coal briquette composition that is easy to handle and has a uniform composition.

In addition, the coal briquette composition according to the present invention may further include an additional binder in an amount of more than 0 and not more than 10,000 parts by weight based on 100 parts by weight of cellulose ether. The additional binder includes molasses, pregelatinized starch, modified starch, polyethylene glycol (PEG), polyvinyl alcohol (PVA), polyacrylamide (PAM), sucrose, liquid glucose, acacia gum, tragacanth gum, Gelatin, alginic acid, polymethyl methacrylate, polyvinylpyrrolidone (PVP), sodium polyacrylate, polyvinylmethyl ether (PLM), alginic acid, asphalt, bitumen (BITUMEN), casein (CASEIN), epoxy resin, pitch ( PITCH), polyamide, polyurethane, and at least one selected from the group consisting of polyvinyl acetal may be used.

On the other hand, the present invention provides a coal briquette comprising the above-mentioned coal briquette composition. The provided coal briquettes have advantages of high thermal efficiency and fast drying speed, and can be used as a heat source in various fields such as thermal power plants, steel mills, small-scale households, agricultural or industrial heating boilers, and the like.

And, since the coal briquettes provided according to the present invention have excellent compressive strength, the rate at which the coal briquettes are damaged by their own load in the process of being stacked or transported inside a container having a specific shape such as a storage tank and a melting furnace can be lowered. In addition, since the coal briquettes have excellent drop strength, the rate of damage due to causes such as drop impacts during the manufacturing process of coal briquettes or the transport process using conveyor belts and large vehicles may also be reduced. Therefore, dust generation due to the damage of coal briquettes is suppressed, and consequently, environmental pollution due to dust generation can be prevented.

The method for producing coal briquettes according to the present invention includes the steps of (1) providing pulverized coal; (2) adding cellulose ether and raw starch that do not gel at 50 to 97° C. into the pulverized coal, followed by dry mixing; (3) wet mixing the dry mixture obtained in step (2) under a temperature environment between the gelation temperature of the raw starch and the gelation temperature of the cellulose ether; (4) mixing the wet mixture obtained in step (3) under a high temperature environment having a temperature higher than that of step (3); and (5) molding the mixture obtained according to step (4) to provide coal briquettes.

Hereinafter, a method for manufacturing coal briquettes according to an embodiment of the present invention will be described in detail step by step.

(1) Pulverized Coal Provision Step

This step is a step for providing pulverized coal. As the pulverized coal, carbon-containing raw materials such as peat, peat, lignite, sub-bituminous coal, bituminous coal, and anthracite coal can be used without limitation. The particle size of the pulverized coal may be 8 mm or less, for example, it may be more than 0 mm and 4 mm or less. In this case, as the pulverized coal, it is possible to use the pulverized coal by pulverizing it according to a known conventional method, or by purchasing pulverized coal that has already been pulverized.

(2) Dry mixing step

In this step, cellulose ether and raw starch that do not gel at 50 to 97° C. are added to the pulverized coal, and then dry-mixed. In this case, individual characteristics such as the type and content of the cellulose ether and raw starch are the same as described above.

In this step, pulverized coal, cellulose ether, and raw starch are mixed in a solid powder form, and after being stored and transported in a dry mixture state, they may be mixed with water in the final use step. Accordingly, it becomes possible to downsize and simplify the storage facility, and to simplify the transport facility. Furthermore, there is no need to worry about freezing in winter.

(3) wet mixing step

This step is a step of wet mixing the dry mixture obtained according to step (2) under a temperature environment between the gelation temperature of the raw starch and the gelation temperature of cellulose ether. This wet mixing step may be performed by injecting high-temperature water having a temperature between the gelation temperature of the raw starch and the gelation temperature of cellulose ether or spraying steam, and preferably, high-temperature water is injected. .

For example, when using the hot water input method, the raw starch can be gelatinized and the viscosity can be maximized according to the hot water input, and the cellulose ether is dissolved in the hot water. Therefore, the temperature of the high-temperature water should be higher than the gelatinization temperature for gelatinization of raw starch, and should be lower than the gelation temperature for inhibiting thermal gelation of the cellulose ether. Preferably, in order to satisfy these conditions, the temperature range of the high temperature water may be 90 ~ 100 ℃. As such, when high-temperature water having a temperature between the gelation temperature of raw starch and the gelation temperature of cellulose ether is used, the hydrogen bond formed between the hydrophilic group and the water molecule is stronger than the activity of the hydrophobic group included in the cellulose ether. Since raw starch can be gelatinized without thermal gelation caused by the breakage of bonds, coal briquettes having excellent drop strength and compressive strength can be provided.

(4) high temperature mixing step

This step is a step of mixing the wet mixture obtained in step (3) under a high temperature environment with a temperature higher than that of step (3).

Specifically, this step is a step for making the gelatinization process of raw starch performed in the "(3) wet mixing step" proceed more sufficiently, and a conventional kneader can be used without limitation. Through this high-temperature mixing process, raw starch can be sufficiently gelatinized and exhibit maximum viscosity, thereby exhibiting the highest adhesive strength.

The high-temperature mixing step may be performed for 5 to 40 minutes in a temperature range of 100 to 150° C. As a result, the strength of the coal briquettes manufactured in the subsequent process can be greatly improved.

(5) forming step

This step is a step of providing coal briquettes by molding the mixture obtained according to step (4). The coal briquettes may be manufactured by a known conventional method, for example, by putting a composition for forming coal briquettes into a mold, pressurizing it to a certain pressure, and then drying it.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1

(Preparation of coal briquette composition)

First, 100 parts by weight of pulverized coal (Kolon, particle size: 0.1 to 5 mm) was prepared. Then, 0.5 parts by weight and 2.5 parts by weight of cellulose ether and raw starch, which are binders, were added to the pulverized coal, respectively, and mixed in an EIRICH mixer (EIRICH, R-02) for 40 seconds to obtain a dry mixture. At this time, the gelatinization temperature of the raw starch is 75° C., and as the cellulose ether, hydroxyethyl methyl cellulose (HEMC) having a methyl substitution degree (DS) of 0.92 and a hydroxyethyl substitution degree (MS) of 1.01 was used. was used. And, the gelation temperature of the HEMC 2.0 wt% aqueous solution was measured with a rheometer (Advanced Rheometer 2000), and gelation did not occur in a temperature range of 50 to 97°C.

After adding 17 parts by weight of distilled water at 95° C. to the dry mixture, the mixture was mixed for 3 minutes using the same Erich mixer (EIRICH, R-02) to obtain a wet mixture.

The wet mixture was further mixed for 15 minutes with a kneader (Hyundai Machinery, OPEN KNEADER) under a high temperature environment of 120° C. to prepare a coal briquette composition.

(Production of coal briquettes)

The coal briquette composition was prepared using a briquetting machine (Jeilsan Machinery Co., Ltd., JCB250T) having an elliptical shape of 51mm in width × 38.2mm in length × 24mm in thickness.

Examples 2 to 5 and Comparative Examples 1 to 5

Coal briquettes were prepared in the same manner as in Example 1, except that the type, content, degree of substitution and gelation temperature of the cellulose ether, and the type and content of starch used were adjusted as described in Table 1 below. In Table 1 below, the gelation temperature of the cellulose ether was measured with a rheometer (Advanced Rheometer 2000), and is a value measured for cellulose ether in a 2.0 wt% aqueous solution state. And, in Table 1 below, N/D indicates that it did not gel in the temperature range of 50 to 97 °C.

raw starch luxury starch
(parts by weight) Cellulose ether content
(parts by weight) glazing temperature
(℃) content
(parts by weight) type DS MS gelation temperature
(℃) Example 1 2.5 75 - 0.5 HEMC 0.92 1.01 N/D Example 2 2.5 75 - 0.5 HEMC 1.29 1.13 N/D Example 3 2.5 75 - 0.5 HEMC 1.11 0.81 N/D Example 4 2.5 75 - 0.5 HEC 0 2.50 N/D Example 5 2.5 75 - 0.5 HEC 0 2.98 N/D Comparative Example 1 2.5 75 - 0.5 HEMC 1.35 0.22 80 Comparative Example 2 2.5 75 - 0.5 HEMC 1.24 0.79 90 Comparative Example 3 2.5 75 - 0.5 HEMC 1.31 2.21 94 Comparative Example 4 2.5 75 - 0.5 HEC 0 0.73 95 Comparative Example 5 - 2.5 0.5 HEMC 0.92 1.01 N/D

* HEMC : Lotte Fine Chemical Co., Ltd., MECELLOSE ^® CB-P039

* HEC : Lotte Fine Chemical Co., Ltd., HECELLOSE ^® H100K

* Raw Starch: Ingredion, Corn Starch

* Luxury starch: Ingredion, Ecostar

< Evaluation method >

1. Drop strength (wt%)

After drying the coal briquettes prepared according to Examples 1 to 5 and Comparative Examples 1 to 5 in an oven at 120° C. for 2 hours, 10 dried coal briquettes were freely dropped from a height of 160 cm 20 times. Then, the weight of the residue remaining after the falling object is filtered through a sieve having an eye width X vertical length of 5 mm is measured, calculated as a percentage of the weight of the coal briquettes before falling, and the value is evaluated as a drop strength did. At this time, it means that the greater the obtained value, the greater the drop strength. The drop strength is a criterion for determining the rate of loss due to the fall when the coal briquettes are dropped onto a conveyor belt or a large vehicle during the manufacturing process or transport process.

2. Compressive strength (kg/cm ² )

Compressive strength of the coal briquettes prepared according to Examples 1 to 5 and Comparative Examples 1 to 5 immediately after molding was measured using a compressive strength tester (Cheel FA, FA-B500). The compressive strength is a criterion for determining the rate at which the coal briquettes are damaged by their own load in the process of being stacked or transported inside a container having a specific shape, such as a storage tank and a melting furnace.

Drop strength (wt%) Compressive strength (kgf/cm ² ) Example 1 85.1 18.3 Example 2 82.7 17.7 Example 3 83.4 17.5 Example 4 84.3 19.2 Example 5 83.9 18.7 Comparative Example 1 53.7 8.2 Comparative Example 2 67.8 9.8 Comparative Example 3 70.9 10.1 Comparative Example 4 72.2 10.7 Comparative Example 5 78.2 15.4

Looking at Table 2, in the case of the coal briquettes prepared according to Examples 1 to 5 containing cellulose ether and raw starch that do not gel at 50 to 97° C., compared to the coal briquettes prepared according to Comparative Examples 1 to 5, the drop strength and It can be seen that the compressive strength is excellent. Among them, in the case of the coal briquettes prepared according to Comparative Example 5 using pre-gelatinized starch, even when cellulose ether that does not gel at 50 to 97°C was used, it showed lower strength compared to the coal briquettes of Examples 1 to 5. It can be seen that the strength of the final coal briquettes is maximized by maximizing the viscosity during the process and showing the best adhesion.

Meanwhile, as described above, “cellulose ether that does not gel at a temperature of 50 to 97° C.” refers to “cellulose ether having a gelation temperature of at least 97° C.”. According to the present invention, cellulose ether having a gelation temperature higher than 97°C, raw starch having a gelation temperature (75°C) lower than the gelation temperature, and hot water having a temperature between the gelation temperature and the gelation temperature (95°C) ), gelatinization of cellulose ether aqueous solution can be suppressed while gelatinization of raw starch is progressed, and as a result, coal briquettes having excellent drop strength and compressive strength can be provided.

As mentioned above, the embodiments disclosed in the present invention are intended to explain, not to limit the technical spirit of the present invention, and the scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be construed as being included in the scope of the present invention.

Claims (16)

delete delete delete delete delete delete delete delete (1) providing pulverized coal;
(2) adding cellulose ether and raw starch that do not gel at 50 to 97° C. into the pulverized coal, followed by dry mixing;
(3) wet mixing the dry mixture obtained in step (2) under a temperature environment between the gelation temperature of the raw starch and the gelation temperature of cellulose ether;
(4) mixing the wet mixture obtained in step (3) under a high temperature environment having a temperature higher than that of step (3); and
(5) A method for producing coal briquettes comprising the step of providing coal briquettes by molding the mixture obtained according to step (4). 10. The method of claim 9,
The step (3) is a method of manufacturing coal briquettes, characterized in that it is performed by injecting high-temperature water having a temperature between the gelation temperature of the raw starch and the gelation temperature of cellulose ether or spraying steam. 11. The method of claim 10,
The method for producing coal briquettes, characterized in that the temperature range of the high-temperature water is 90 ~ 100 ℃. 10. The method of claim 9,
The step (4) is a method of manufacturing coal briquettes, characterized in that it is performed for 5 to 40 minutes under a high temperature environment of 100 ~ 150 ℃. 10. The method of claim 9,
The method for producing coal briquettes, characterized in that the gelation temperature of the cellulose ether is higher than the gelatinization temperature of the raw starch. 10. The method of claim 9,
The cellulose ether is at least one selected from the group consisting of alkyl cellulose, hydroxyalkyl cellulose, hydroxyalkyl alkyl cellulose, and alkyl alkyl hydroxylalkyl cellulose. A method of manufacturing coal briquettes comprising a. 10. The method of claim 9,
The cellulose ether is hydroxyethyl cellulose (hydroxyethyl cellulose; HEC) having a hydroxyethyl substitution degree (MS) of 0.8 or more and 4.0 or less; hydroxyethyl methyl cellulose (HEMC) having a methyl substitution degree (DS) of greater than 0 and 1.3 and a hydroxyethyl substitution degree (MS) of 0.8 or more and 4.0 or less; and hydroxypropyl methyl cellulose (HPMC) having a methyl substitution degree (DS) of more than 0 and 1.0 or less and a hydroxypropyl substitution degree (MS) of 0.1 or more and 0.25 or less; containing at least one selected from the group consisting of A method of manufacturing coal briquettes, characterized in that 10. The method of claim 9,
Based on 100 parts by weight of the pulverized coal, the content of the cellulose ether is 0.1 to 1.0 parts by weight, and the content of the raw starch is 0.1 to 5.0 parts by weight.