KR20210047049A - Starch-based aqueous composition for binding inorganic materials and briquette for steelmaking material prepared by using the same as a binder - Google Patents

Abstract

The present invention relates to a starch-based aqueous composition for binding inorganic materials and briquette for a steelmaking material prepared by using the same as a binder, and more particularly, to a starch-based aqueous composition for binding inorganic materials, which is based on starch-based raw materials to be eco-friendly and the manufacturing process is simple, and when used as a binder for in the manufacture of briquettes for steel raw materials, briquetting is possible even at low solids by combining with inorganic substances, and thus compared to molasses, which has been commonly used in the past, the strength of briquette is improved even with a reduced amount of input to be capable of reducing the amount of dust generated during the process, and relates to briquette for a steelmaking material prepared by using the same as a binder.

Description

Starch-based aqueous composition for binding inorganic materials and briquette for steelmaking material prepared by using the same as a binder}

The present invention relates to a starch-based aqueous composition for binding inorganic substances and briquettes for iron-making raw materials manufactured using the same as a binder, and more particularly, to an eco-friendly and simple manufacturing process based on starch-based raw materials, and briquettes for iron-making raw materials. When used as a binder in manufacturing, briquetting is possible by combining with inorganic substances even at low solids, so the strength of briquettes is improved even with a reduced input amount compared to molasses, which has been commonly used in the past, thereby reducing the amount of dust generated during the process. It relates to an aqueous composition and briquettes for iron-making raw materials prepared by using the same as a binder.

In the steel making process, dust or slag containing iron powder and other metallic substances is generated in the blast furnace and steel making process, and recycling the generated dust can help reduce manufacturing cost and prevent air pollution, so research and development to recycle it. And field application cases are actively progressing.

In the case of dust, since it is fine, it is not suitable for direct use, and it is manufactured and used as briquettes through mixing with a binder. However, since such briquettes can regenerate dust as they fall during the manufacturing process and transport, there is a need for a binder that can increase the initial strength of the briquettes.

In Korean Patent No. 10-0518326, molasses was used to inject coal into the melting furnace in the FINEX and COREX processes, and the coal briquettes were manufactured, and in Korean Patent No. 10-0905581, molasses was used as a binder to produce dust. , Slag, sludge, and the like were recycled, and in Korean Patent No. 10-1018251, pellets and briquettes were manufactured using molasses as slag and sludge and binders having various particle sizes.

Molasses comes from Latin and is a by-product of the sugar manufacturing process. Sugarcane molasses is a by-product produced in the manufacture or refining of sugarcane raw sugar, and it contains sugar, so it is widely used in the fermentation industry. The components of molasses are generally sucrose, glucose, and fructose, and glucose and fructose are called reducing sugars, and have a solid content of about 75 to 85% by weight. Inorganic components in molasses consist of potassium, calcium, magnesium, sodium, iron, sulfate, chloride, phosphate, and silicon dioxide. In the case of using raw sugar cane, sulfur vapor is added during the sugar extraction process, which increases the sulfur (S) content in molasses.

In the iron making process, iron ore and bituminous coal are used to make molten iron, which contains sulfur (S), and the process of removing impurities from the iron is carried out in the steel making process. When molasses is used as a binder in such a process, sulfur (S) components contained in molasses are added, which can affect production efficiency and cause corrosion of equipment. In addition, molasses sludge accumulates in the device, causing deformation and failure.

Therefore, it can replace molasses by showing excellent bonding strength to dust, slag, sludge, etc. generated in the iron making process without using molasses, while improving the strength of briquettes with a reduced input amount compared to molasses, thereby reducing the amount of dust generated during the process. There is a demand for the development of a binder composition that can be reduced.

The present invention is intended to solve the problems of the prior art as described above, and can replace molasses by showing excellent bonding strength to dust, slag, sludge, etc. generated in the iron making process, while reducing the strength of briquettes with a reduced input amount compared to molasses. It is a technical problem to provide a composition that can be improved and briquettes for iron-making raw materials prepared by using the same as a binder.

In order to achieve the above-described technical problem, the present invention includes starch and a basic substance as a blending raw material component, and water as a medium, and the starch corresponds to 1 to 30 parts by weight within 100 parts by weight of the composition based on solid content. It is included in an amount, and the basic material is included in an amount corresponding to 1 to 20 parts by weight based on 100 parts by weight of starch solids based on solid content, providing a starch-based aqueous composition for binding inorganic substances.

According to another aspect of the present invention, there is provided a method for preparing an aqueous starch-based composition for binding inorganic substances, comprising the steps of: (1) dispersing starch in water as a medium; And (2) adding and mixing a basic material to the result of step (1), wherein the starch is used in an amount corresponding to 1 to 30 parts by weight in 100 parts by weight of the composition based on solid content, There is provided a method for preparing a starch-based aqueous composition for binding inorganic substances using the basic substance in an amount corresponding to 1 to 20 parts by weight based on 100 parts by weight of starch solids based on solid content.

According to another aspect of the present invention, there is provided a briquette for iron-making raw materials prepared by using the starch-based aqueous composition for binding inorganic substances of the present invention as a binder.

Since the starch-based aqueous composition according to the present invention is based on a starch-based raw material, it is eco-friendly, has a simple manufacturing process, and has excellent viscosity stability in a liquid form containing gelatinized starch. In addition, when using the starch-based aqueous composition according to the present invention as a binder in the manufacture of briquettes for iron-making raw materials using dust, slag, sludge, etc. generated in the iron-making process, the amount of input reduced compared to the existing molasses binder (e.g., existing 70% of the amount of molasses input) can also improve the strength of briquettes (e.g., the initial strength of briquettes (e.g., 20% or more improved compared to when molasses is used)), reducing manufacturing costs while reducing the amount of dust generated during the process. I can.

1 is a photograph of the surface of briquettes prepared in an embodiment of the present invention after drying.

Hereinafter, the present invention will be described in more detail.

The starch-based aqueous composition for binding inorganic substances of the present invention contains starch and a basic substance as raw material components for mixing, and water as a medium.

As the starch, starch selected from corn starch, waxy corn starch, tapioca starch, oxidized starch, acetic acid starch, dextrin, phosphate starch, crosslinked starch, and combinations thereof may be used, preferably waxy corn starch. .

The starch-based aqueous composition for binding inorganic substances of the present invention contains the starch in an amount corresponding to 1 to 30 parts by weight in 100 parts by weight of the composition based on solid content. If the starch content in the composition is lower than the above level, adhesion to inorganic substances may be lowered, and the strength of briquettes prepared by using this as a binder may decrease. Conversely, if the starch content in the composition is higher than the above level, there may be limitations in the manufacturing process due to an increase in viscosity during starch gelatinization.

In one embodiment, the starch content in 100 parts by weight of the starch-based aqueous composition for binding inorganic substances of the present invention is 2 parts by weight or more, 4 parts by weight or more, 6 parts by weight or more, 8 parts by weight or more, or 10 parts by weight based on solid content. It may be greater than or equal to 28 parts by weight, 26 parts by weight or less, 24 parts by weight or less, 22 parts by weight or less, or 20 parts by weight or less.

The basic material may be selected from sodium hydroxide, potassium hydroxide, ammonia, and combinations thereof, but is not limited thereto.

The starch-based aqueous composition for binding inorganic substances of the present invention contains the basic substance in an amount corresponding to 1 to 20 parts by weight based on 100 parts by weight of starch solid content. If the content of the base material in the composition is lower than the above level, the viscosity increases, and thus mixing may be difficult. Conversely, if the content of the base material in the composition is higher than the above level, the starch may be too gelatinized and the adhesion may be lowered.

In one embodiment, the starch content in 100 parts by weight of the starch-based aqueous composition for binding inorganic substances of the present invention is 1.5 parts by weight or more, 2 parts by weight or more, 2.5 parts by weight or more, 3 parts by weight or more, or 3.5 parts by weight based on solid content. It may be greater than or equal to 18 parts by weight, 16 parts by weight or less, 14 parts by weight or less, 12 parts by weight or less, or 10 parts by weight or less.

In one embodiment, the solid content of the starch-based aqueous composition for binding inorganic substances of the present invention may be 40% by weight or less (eg, 1 to 40% by weight) or 30% by weight or less (eg, 1 to 30% by weight). . If the solid content of the composition is too high than the above level, there may be limitations on the manufacturing process due to the increase in viscosity during starch gelatinization, whereas if it is too low than the above level, the adhesive strength is lowered, and the strength of the briquette prepared using this as a binder decreases. I can.

More specifically, the solid content of the starch-based aqueous composition for binding inorganic substances of the present invention may be 2% by weight or more, 4% by weight or more, 6% by weight or more, or 8% by weight or more, and also 35 parts by weight or less, 30% by weight or less. , It may be 25% by weight or less or 20% by weight or less.

According to another aspect of the present invention, there is provided a method for preparing an aqueous starch-based composition for binding inorganic substances, comprising the steps of: (1) dispersing starch in water as a medium; And (2) adding and mixing a basic material to the result of step (1), wherein the starch is used in an amount corresponding to 1 to 30 parts by weight in 100 parts by weight of the composition based on solid content, There is provided a method for preparing a starch-based aqueous composition for binding inorganic substances using the basic substance in an amount corresponding to 1 to 20 parts by weight based on 100 parts by weight of starch solids based on solid content.

In the method for preparing an aqueous starch-based composition for binding inorganic substances of the present invention, step (2) may be performed under stirring in a heated (eg, 50 to 70° C.) state.

The starch-based aqueous composition for binding inorganic substances of the present invention is reduced to a level of 60 to 70% by weight compared to the amount of molasses when used as a binder in the production of briquettes for iron-making raw materials using dust, slag, sludge, etc. generated in the iron-making process. Even if the amount is used, the strength can be improved by more than 20% compared to the use of molasses.

Accordingly, according to another aspect of the present invention, there is provided a briquette for iron-making raw materials prepared by using the starch-based aqueous composition for binding inorganic substances as a binder.

Briquettes for iron-making raw materials provided according to the present invention include a raw material inorganic material and the above binder (ie, the starch-based aqueous composition for binding inorganic materials of the present invention).

In one embodiment, the raw material inorganic material may be a metallic material, which may be derived from dust, slag, or sludge generated in an iron making process.

In one embodiment, the amount of the binder used in the manufacture of briquettes for iron-making raw materials of the present invention may be 1 to 15 parts by weight based on 100 parts by weight of the raw material inorganic material, more specifically 1 to 10 parts by weight, more specifically May be 1 to 5 parts by weight.

Briquettes for iron-making raw materials provided according to the present invention may additionally contain moisture during molding. The moisture (ie, water) may be derived from an aqueous binder composition, may be additionally added for dilution of the binder, or both.

In one embodiment, the moisture content of briquettes for iron-making raw materials provided according to the present invention may be 1 to 20% by weight based on 100% by weight of briquettes, more specifically 5 to 15% by weight, more specifically It may be 8 to 12% by weight.

In one embodiment, the intensity of briquettes for iron-making raw materials provided according to the present invention may be prepared and analyzed by the following method.

The raw material inorganic material (e.g., dust), the binder composition, and optionally additional water are mixed and kneaded for 1 to 5 minutes, then molded by a compression press to produce briquettes, and the prepared briquettes are initially weighed to break through free fall. You can check the strength. In addition, after drying the briquette, the strength of the briquette can be checked using a compressive strength meter.

Hereinafter, the present invention will be described in more detail through Examples and Comparative Examples. However, the scope of the present invention is not limited to these.

[ Example ]

Example One

A liquid binder composition was prepared according to the conditions shown in Table 1 below. Waxy corn starch was used as the starch, and sodium hydroxide was used as the base material. Molasses was used as a control.

Briquettes were prepared using the control molasses and each prepared liquid binder composition. As the raw material inorganic material used in the manufacture of briquettes, dust generated in the iron making process was commonly used. In the case of molasses, 2 and 4 parts by weight relative to 100 parts by weight of dust were added, and the liquid binder composition was added in 2 parts by weight. After mixing the raw material inorganic dust and the binder, 20 to 25 g each were put into a circular molding mold having a diameter of 30 mm and a height of 50 mm, and pressed for 20 seconds with a force of about 15 tons to prepare briquettes. The prepared briquette was dried at 50° C. for 12 hours, and then strength analysis was performed using a compressive strength meter, and the results are shown in Table 1 below.

[Table 1]

As can be seen from Table 1, it was confirmed that when briquettes were prepared by applying the liquid binder composition according to the present invention, the same or superior briquette strength was obtained compared to when molasses was used, and the amount of binder used could be reduced compared to when molasses was used, so production cost A reduction effect was also obtained.

Example 2

As an index for the initial strength of briquettes, the amount of dust (14 mesh (particle spacing 1.4 mm) sieve pass) generated by falling 5 times from a height of about 2 m immediately after molding (the briquette weight before drop test: 100% by weight) was measured. . Preparation of the binder composition and briquette was carried out in the same manner using the same raw material as in Example 1, and molasses was used as a control. The amount of the binder added was 2 parts by weight compared to 100 parts by weight of dust, and the moisture content during briquette molding was 10% by weight. The binder manufacturing conditions and the amount of dust generated are shown in Table 2 below.

[Table 2]

As can be seen from Table 2, when briquettes are prepared by applying the liquid binder composition according to the present invention, the initial strength of briquettes is better compared to when molasses is used, so that the amount of dust generation can be significantly reduced.

Example 3

In the case of molasses, due to its high viscosity, it is often diluted and used, and depending on the application, the moisture content of the briquette is adjusted to the amount of binder added. Therefore, the physical properties of briquettes according to the dilution of the prepared binder were confirmed.

[Table 3]

As can be seen from Table 3, when briquettes are prepared by applying the liquid binder composition according to the present invention, the initial strength of briquettes is significantly improved (that is, the amount of dust generated is significantly reduced) even with a reduced amount of binder added compared to when molasses is used. Could.

In addition, the briquette surface was checked after drying at 200° C. for 1 hour to remove moisture after the briquette production, and pictures of the surface after drying of the briquettes are shown in FIG. As can be seen from FIG. 1, cracks were not observed on the briquette surface in both the molasses and the liquid binder applied samples.

Example 4

The physical properties of briquettes were confirmed according to the mixing time of the inorganic dust and the binder.

In the case of molasses, molasses:water was diluted in a weight ratio of 6:4, and a liquid binder and a binder:water were diluted in a weight ratio of 6:4. After the diluted binder was added to the inorganic dust so that the moisture content of the briquette was 6% by weight, the mixing time was changed from 1 minute to 5 minutes. The liquid binder used was prepared under the conditions of 12.5% by weight of solid content, 11.5 parts by weight of starch and 9.0 parts by weight of base when preparing the binder. For the prepared briquette, the amount of dust generated was measured in the same manner as in Example 2, and the results are shown in Table 4 below.

[Table 4]

As can be seen from Table 4, in the case of manufacturing briquettes by applying the liquid binder composition according to the present invention, the initial strength of briquettes is significantly improved compared to when molasses is used, even if the mixing time of inorganic dust and binder is different (i.e., the amount of dust generated is increased). Remarkably reduced).

Claims (7)

It contains starch and a basic substance as a blending raw material component, and contains water as a medium,
The starch is contained in an amount corresponding to 1 to 30 parts by weight in 100 parts by weight of the composition based on solid content,
The basic substance is contained in an amount corresponding to 1 to 20 parts by weight based on 100 parts by weight of starch solid content, based on the solid content,
A starch-based aqueous composition for binding inorganic substances. The starch-based aqueous composition for binding inorganic substances according to claim 1, wherein the starch is selected from corn starch, waxy corn starch, tapioca starch, oxidized starch, starch acetate, dextrin, starch phosphate, crosslinked starch, and combinations thereof. The starch-based aqueous composition for binding inorganic substances according to claim 1, wherein the basic substance is selected from sodium hydroxide, potassium hydroxide, ammonia, and combinations thereof. The starch-based aqueous composition for binding inorganic substances according to claim 1, wherein the solid content is 40% by weight or less. As a method for preparing a starch-based aqueous composition for binding inorganic substances,
(1) dispersing starch in water as a medium; And
(2) adding and mixing a basic substance to the resultant of the step (1); including,
The starch is used in an amount corresponding to 1 to 30 parts by weight in 100 parts by weight of the composition based on solid content, and the basic substance is used in an amount corresponding to 1 to 20 parts by weight based on 100 parts by weight of starch solid content. How to use. Briquettes for iron-making raw materials prepared by using the starch-based aqueous composition for binding inorganic substances according to any one of claims 1 to 4 as a binder. The briquette for iron-making raw materials according to claim 6, wherein the moisture content is 1 to 20% by weight during molding.

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