KR102469996B1 - Binder for coal briquette - Google Patents

Abstract

A binder for coal briquettes is disclosed. The disclosed binder for briquettes includes at least one cellulose ether-based compound selected from the group consisting of alkyl cellulose, hydroxyalkyl cellulose, and hydroxyalkylalkyl cellulose having a viscosity of 1,000 to 80,000 cps. The binder for the coal briquettes may not require an additional strength reinforcing agent, and high-strength coal briquettes capable of simplifying the manufacturing process of the coal briquettes may be manufactured.

Description

Binder for coal briquettes {Binder for coal briquette}

A binder for coal briquettes is disclosed. More specifically, a binder for briquettes including a cellulose ether-based compound having a specific viscosity range is disclosed.

The steelmaking process includes an iron making process for producing molten iron by charging iron ore and coal into a blast furnace, and a steelmaking process for producing high purity molten steel by removing impurities contained in the molten iron. making process), a casting process for manufacturing semi-finished products such as solid slabs from liquid molten steel, and a rolling process for manufacturing final steel products by processing semi-finished products such as slabs. do.

In the new steelmaking process, the fine ore reduction process (FINEX) and the smelting reduction process (COREX), bituminous coal is not processed into coke, unlike in the existing steelmaking process, but is put into the melting furnace in its original state and used.

Bituminous coal having a particle size of more than 8 mm can be used immediately without special processing, but use of bituminous coal having a particle size of 8 mm or less is limited due to dust generation during operation. Therefore, bituminous coal having a particle size of 8 mm or less is used after being processed into coal briquettes having a certain particle size.

When processing bituminous coal having a small particle size as described above into coal briquettes, molasses is conventionally mainly used as a binder. However, when molasses is used as a binder, the following various disadvantages occur.

First, when molasses is used as a binder, since the strength of finally produced coal briquettes is weak, a strength enhancer such as quicklime, bentonite, or a mixture thereof must be additionally used to enhance the strength of the coal briquettes.

Next, a bad odor originating from molasses occurs during operation.

In addition, since molasses has a sticky liquid form and its viscosity increases as the temperature decreases, there is a problem in that molasses adheres to storage tanks, pipes, and nozzles during storage, transportation, and spraying. Therefore, equipment (for example, a high-pressure pump and a heating device) for preventing and avoiding these problems is required. Therefore, when molasses is used as a binder, there is a disadvantage in that the manufacturing process of coal briquettes becomes complicated.

In addition, since molasses is derived from a natural material, it is difficult to maintain a constant quality of coal briquettes because its viscosity is not constant depending on the supply source, supplier, and supply time.

In addition, since molasses is a liquid and has a low density, a large amount must be used, so a large-capacity storage facility is required, and there is a disadvantage in increasing the amount of transportation and thus the transportation cost.

In addition, molasses has the disadvantage of unstable supply and demand and unit price.

One embodiment of the present invention provides a binder for briquettes including at least one cellulose ether-based compound selected from the group consisting of alkyl cellulose, hydroxyalkyl cellulose, and hydroxyalkylalkyl cellulose having a specific viscosity range.

One aspect of the present invention is,

A binder for briquettes containing at least one cellulose ether-based compound selected from the group consisting of alkyl cellulose, hydroxyalkyl cellulose, and hydroxyalkyl alkyl cellulose having a viscosity of 1,000 to 80,000 cps is provided.

The binder for coal briquettes may be used to manufacture coal briquettes by binding pulverized coal.

The pulverized coal may be bituminous coal having a particle size of 8 mm or less, in particular, 4 mm or less.

The cellulose ether compound is selected from the group consisting of methyl cellulose (MC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), hydroxypropyl methyl cellulose (HPMC) and hydroxyethyl methyl cellulose (HEMC) It may contain at least one substance.

The methyl cellulose (MC) has a degree of substitution of a methyl group of 18 to 32 wt%, the hydroxyethyl cellulose (HEC) has a degree of substitution of a hydroxyethyl group of 20 to 80 wt%, and the hydroxypropyl cellulose (HPC) has a degree of substitution of a hydroxyethyl group of 20 to 80 wt% It has a degree of substitution of a hydroxypropyl group of ~ 80 wt%, and the hydroxypropylmethylcellulose (HPMC) has a degree of substitution of a methyl group of 18 to 32 wt% and a degree of substitution of a hydroxypropyl group of 2 to 14 wt%, and the hydroxyethyl Methyl cellulose (HEMC) may have a methyl group substitution degree of 18 to 32 wt% and a hydroxyethyl group substitution degree of 2 to 14 wt%.

The cellulose ether-based compound may be used in an amount of 0.01 to 15.0 parts by weight based on 100 parts by weight of the pulverized coal.

The binder for the briquettes may further include more than 0 to 10,000 parts by weight of an additional binder based on 100 parts by weight of the cellulose ether-based compound.

The additional binder is molasses, corn starch, wheat starch, potato starch, polyethylene glycol (PEG), polyvinyl alcohol (PVA), polyacrylamide (PAM), sucrose, liquid glucose, acacia gum, tragacanth gum ), gelatin, alginic acid, polymethacrylate, polyvinylpyrrolidone (PVP), sodium polyacrylate, polyvinylmethyl ether (PLM), alginic acid, asphalt, bitumen (BITUMEN), casein (CASEIN), epoxy resin, pitch (PITCH), polyamide, polyurethane, and at least one material selected from the group consisting of polyvinyl acetal.

The binder for briquettes according to an embodiment of the present invention includes a cellulose ether-based compound having a specific viscosity range, thereby reducing the total amount of binder (up to 1/10 of the amount of molasses when 100% molasses is used), and additional strength A reinforcing agent may not be required, a process for manufacturing coal briquettes may be simplified, and high-strength coal briquettes capable of maintaining a stable supply and demand and price compared to molasses may be manufactured.

In addition, since the binder for coal briquettes containing the cellulose ether-based compound is colorless and odorless, it is possible to improve a working environment without generating an odor.

Hereinafter, a binder for coal briquettes according to an embodiment of the present invention will be described in detail. The binder for coal briquettes according to an embodiment of the present invention includes one or more cellulose ethers selected from the group consisting of alkyl cellulose, hydroxyalkyl cellulose, and hydroxyalkylalkyl cellulose having a viscosity of 1,000 to 80,000 cps (centipoises) or mPa·s contains a compound

In the present specification, the "viscosity of the cellulose ether-based compound" is the viscosity measured using Brookfield's DV-II + Pro (spindle HA), and is an aqueous solution of a cellulose ether-based compound having a concentration of 2% by weight at 20 ± 0.1 ° C. means viscosity.

If the viscosity of the cellulose ether-based compound is less than 1,000cps, the viscosity of the solution (eg, aqueous solution) containing the cellulose ether-based compound is too low, so that the bonding strength of the cellulose ether-based compound to the pulverized coal is reduced, and 80,000cps If it is exceeded, the molecular weight of the cellulose ether-based compound is high and solubility in water is poor, and the binding force to the pulverized coal is not sufficiently exhibited.

The viscosity of the cellulose ether-based compound is, for example, 2,000 to 70,000cps, for example 6,000 to 60,000cps, for example 7,000 to 50,000cps, for example 8,000 to 40,000cps, for example 9,000 to 30,000cps, for example For example, it may be 10,000 to 20,000 cps.

The binder for coal briquettes may be used to manufacture coal briquettes by binding pulverized coal. In this specification, "pulverized coal" means coal having a particle size of 8 mm or less.

The pulverized coal may be bituminous coal. In this specification, "bituminous coal" means relatively soft coal containing a tar-like material called bitumen.

The pulverized coal may have a particle size of 4 mm or less. When the particle size of the pulverized coal is 4 mm or less, it is possible to prevent the pulverized coal from being destroyed by pressure applied thereto during the manufacturing process of the coal briquettes. Accordingly, when the particle size of the pulverized coal is 4 mm or less, the finally produced coal briquettes may maintain high strength.

The cellulose ether-based compound serves to bind the particles of the pulverized coal to each other.

The cellulose ether-based compound not only dissolves well in water, but also does not clog the nozzle hole because it does not precipitate on the inner surface of the nozzle when sprayed through the nozzle in an aqueous solution. In addition, since the cellulose ether-based compound is stored and transported alone or mixed with pulverized coal in the form of a solid powder and mixed with water in the final use stage, miniaturization and simplification of storage facilities and transport facilities are possible. . In addition, since the cellulose ether-based compound can obtain the same binding effect even with a smaller amount than molasses, it is possible to reduce material costs. In addition, the cellulose ether-based compound has an advantage in that coal briquettes having excellent strength can be obtained without using a strength reinforcing agent.

The cellulose ether-based compound may not include carboxymethyl cellulose (CMC). If the cellulose ether-based compound includes carboxymethylcellulose (CMC), the strength of the coal briquettes manufactured using the composition for forming coal briquettes including the binder for coal briquettes may be reduced.

The cellulose ether compound is selected from the group consisting of methyl cellulose (MC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), hydroxypropyl methyl cellulose (HPMC) and hydroxyethyl methyl cellulose (HEMC) It may contain at least one substance.

The methyl cellulose (MC) has a degree of substitution of a methyl group of 18 to 32 wt%, the hydroxyethyl cellulose (HEC) has a degree of substitution of a hydroxyethyl group of 20 to 80 wt%, and the hydroxypropyl cellulose (HPC) has a degree of substitution of a hydroxyethyl group of 20 to 80 wt% It has a degree of substitution of a hydroxypropyl group of ~ 80 wt%, and the hydroxypropylmethylcellulose (HPMC) has a degree of substitution of a methyl group of 18 to 32 wt% and a degree of substitution of a hydroxypropyl group of 2 to 14 wt%, and the hydroxyethyl Methyl cellulose (HEMC) may have a methyl group substitution degree of 18 to 32 wt% and a hydroxyethyl group substitution degree of 2 to 14 wt%.

The cellulose ether-based compound may be used in an amount of 0.01 to 15.0 parts by weight based on 100 parts by weight of the pulverized coal. When the amount of the cellulose ether-based compound is within the above range, high-strength coal briquettes can be obtained even with a small addition amount compared to molasses.

The binder for the briquettes may further include more than 0 to 10,000 parts by weight of an additional binder based on 100 parts by weight of the cellulose ether-based compound. When the content of the additional binder is within the above range, the manufacturing cost of the binder for the coal briquettes may be reduced by reducing the amount of the cellulose ether-based compound, and the drying speed of the composition for forming the coal briquettes including the binder for the coal briquettes may be increased It is possible to obtain coal briquettes with less dust generation and improved strength.

The additional binder is molasses, corn starch, wheat starch, potato starch, polyethylene glycol (PEG), polyvinyl alcohol (PVA), polyacrylamide (PAM), sucrose, liquid glucose, acacia gum, tragacanth gum ), gelatin, alginic acid, polymethacrylate, polyvinylpyrrolidone (PVP), sodium polyacrylate, polyvinylmethyl ether (PLM), alginic acid, asphalt, bitumen (BITUMEN), casein (CASEIN), epoxy resin, pitch (PITCH), polyamide, polyurethane, and at least one material selected from the group consisting of polyvinyl acetal.

The binder for coal briquettes may provide a binder for coal briquettes having improved strength even if it does not include a strength reinforcing agent such as quicklime, bentonite, or other materials capable of enhancing the strength of the coal briquettes.

Another embodiment of the present invention provides coal briquettes manufactured using the binder for coal briquettes.

When the coal briquettes are manufactured using the binder for the coal briquettes, water in an amount of greater than 0 to 15.0 parts by weight may be used based on 100 parts by weight of the pulverized coal. When the water content is within the above range, a composition for forming coal briquettes that is easy to handle and has a uniform composition can be obtained, and a phenomenon in which some components of the composition for forming coal briquettes are adhered to the surface of the molding machine can be prevented in the coal briquette molding process. have.

Coal briquettes manufactured using the binder for coal briquettes are not used in the coke manufacturing process, but may be used as a heat source in the FINEX process and the Corex process. Therefore, the coal briquettes prepared above have the advantage of high thermal efficiency and fast drying speed.

A method of manufacturing coal briquettes from the binder for coal briquettes is as follows. That is, a composition for forming coal briquettes is prepared by mixing the binder for coal briquettes, pulverized coal, and water, and the prepared composition for forming coal briquettes is put into a mold and pressurized at a predetermined pressure to manufacture coal briquettes.

The binder for coal briquettes may provide a binder for coal briquettes having improved strength even if it does not include a strength reinforcing agent.

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

Example 1-9 and comparative example 1 to 4

(Preparation of composition for forming coal briquettes including binder for briquettes)

Pulverized coal (SK networks, particle size: 0.1-5mm) and optionally hydroxypropylmethylcellulose, carboxymethylcellulose (CMC) (ASHILAND, AQUALON ^TM , viscosity: 6,000cps), molasses (Casey Industrial Environment Co., Ltd., solid content: 77.2 wt%, total equivalent: 49.3wt%), quicklime (Chungmu Chemical Co., Ltd., CaO content: 70wt% or more, fineness: 95wt% passed through a 170 Mesh (89㎛) sieve) mixed with the composition and content shown in Table 1 below Thus, the first composition was obtained. Thereafter, distilled water was added to the first composition to obtain a composition for forming coal briquettes. The contents of the components used in each of the Examples and Comparative Examples are shown in Table 1 below.

(Manufacture of coal briquettes)

The prepared composition for forming coal briquettes was compressed and molded with a load of 70 kN using a Briquette machine (Jil Industrial Co., Ltd., JCB250T) to manufacture 50 coal briquettes, and then 30 coal briquettes excluding the first and last 20 coal briquettes were selected. . The manufactured coal briquettes each had a weight of 5 to 10 g.

Mixing ratio (parts by weight) pulverized coal molasses Distilled water quicklime HPMC CMC One 2 3 4 5 Example 1 100 0 10 0 One 0 0 0 0 0 Example 2 100 0 10 0 3 0 0 0 0 0 Example 3 100 0 10 0 5 0 0 0 0 0 Example 4 100 0 10 0 7 0 0 0 0 0 Example 5 100 2 8 0 5 0 0 0 0 0 Example 6 100 2 8 0 3 0 0 0 0 0 Example 7 100 2 8 0 2 0 0 0 0 0 Example 8 100 0 10 0 0 One 0 0 0 0 Example 9 100 0 10 0 0 0 One 0 0 0 Comparative Example 1 100 0 10 0 0 0 0 One 0 0 Comparative Example 2 100 0 10 0 0 0 0 0 One 0 Comparative Example 3 100 0 10 0 0 0 0 0 0 One Comparative Example 4 100 8 One 3 0 0 0 0 0 0

HPMC1: Samsung Fine Chemical Co., Ltd., Mecellose ^® PMC (PMC-60U), viscosity: 60,000 cps, methyl group substitution degree: 23.2wt%, hydroxypropyl group substitution degree: 8.8wt%

HPMC2: Samsung Fine Chemical Co., Ltd., Mecellose ^® PMC (PMB-40H), viscosity: 4,000cps, methyl group substitution degree: 28.6wt%, hydroxypropyl group substitution degree: 6.1wt%

HPMC3: Samsung Fine Chemical Co., Ltd., HPMC, viscosity: 80,000cps, methyl group substitution degree: 22.8wt%, hydroxypropyl group substitution degree: 9.1wt%

HPMC4: Samsung Fine Chemical Co., Ltd., HPMC, viscosity: 500cps, methyl group substitution degree: 26.4wt%, hydroxypropyl group substitution degree: 8.2wt%

HPMC5: Samsung Fine Chemical Co., Ltd., HPMC, viscosity: 85,000cps, methyl group substitution degree: 22.6wt%, hydroxypropyl group substitution degree: 9.2wt%

CMC: ASHILAND, AQUALON ^TM , Viscosity: 6,000cps

evaluation example

evaluation example One

The impact strength and compressive strength of the coal briquettes prepared in Examples 1 to 9 and Comparative Examples 1 to 4 were evaluated in the following manner, and the results are shown in Table 2 below.

(impact strength evaluation)

A rectangular parallelepiped tray (total weight: 0.5 kg) filled with sand was dropped from a height of 50 cm upward from 10 coal briquettes toward the coal briquettes. This drop test was repeated two more times, 10 at a time, with respect to the remaining 20 coal briquettes. Thereafter, the total weight of particles having a size of 10 mm or more among the remaining coal briquettes was expressed as a percentage of the weight of the coal briquettes before falling, and the value was evaluated as impact strength. At this time, the higher the obtained value, the higher the impact strength. The impact strength is a criterion for determining the rate at which each coal briquette is lost by falling several times when transported by a conveyor belt.

(compressive strength evaluation)

The maximum strength when the coal briquettes were compressed at a speed of 5 mm/min in a universal testing machine (Xinjiang Precision Industry Co., Ltd., AD-universal testing machine-kN) was measured and recorded as compressive strength. The compressive strength is a criterion for determining the rate at which each coal briquette is damaged by its own load when stored in a storage tank.

Example comparative example One 2 3 4 5 6 7 8 9 One 2 3 4 Impact strength (%) 83 85 88 93 95 90 85 84 85 73 74 70 78 Compressive strength (MPa) 9.9 10.5 11.2 13.1 15.3 12.3 10.8 9.8 10.1 8.9 9.1 7.5 9.3

Referring to Table 2, the coal briquettes manufactured in Examples 1 to 9 had higher impact strength and compressive strength than those of the coal briquettes manufactured in Comparative Examples 1 to 4.

Although the present invention has been described with reference to examples, these are only examples, and those skilled in the art will understand that various modifications and equivalent other implementations are possible therefrom. Therefore, the true technical scope of protection of the present invention should be determined by the technical spirit of the appended claims.

Claims (6)

It is for manufacturing coal briquettes by binding pulverized coal, and includes a cellulose ether-based compound having a viscosity of 4,000 to 80,000cps,
The viscosity of the cellulose ether-based compound is a viscosity measured using Brookfield's DV-II + Pro (spindle HA), and refers to the viscosity of an aqueous solution of a cellulose ether-based compound having a concentration of 2% by weight at 20 ± 0.1 ° C.,
The cellulose ether compound includes hydroxypropylmethylcellulose (HPMC) having a methyl group substitution degree of 18 to 32 wt% and a hydroxypropyl group substitution degree of 2 to 14 wt%,
The cellulose ether-based compound does not include carboxymethyl cellulose (CMC),
A binder for coal briquettes further comprising more than 0 to 10,000 parts by weight of an additional binder based on 100 parts by weight of the cellulose ether-based compound. delete delete According to claim 1,
The cellulose ether-based compound is used in an amount of 0.01 to 15.0 parts by weight based on 100 parts by weight of the pulverized coal. delete According to claim 1,
The additional binder is molasses, corn starch, wheat starch, potato starch, polyethylene glycol (PEG), polyvinyl alcohol (PVA), polyacrylamide (PAM), sucrose, liquid glucose, acacia gum, tragacanth gum ), gelatin, alginic acid, polymethacrylate, polyvinylpyrrolidone (PVP), sodium polyacrylate, polyvinylmethyl ether (PLM), alginic acid, asphalt, bitumen (BITUMEN), casein (CASEIN), epoxy resin, pitch A binder for briquettes comprising at least one material selected from the group consisting of (PITCH), polyamide, polyurethane, and polyvinyl acetal.