KR20230093962A - Binder composition using carbonated gypsum - Google Patents

Abstract

The present invention relates to a binder composition using carbonate gypsum as an irritant.
The present invention provides a binder composition containing 10 to 3,000 parts by weight of blast furnace slag fine powder with respect to 100 parts by weight of carbonate gypsum produced by mixing water with petro-coke desulfurization gypsum to perform a hydration reaction and then capturing carbon dioxide and performing a mineral carbonation reaction. After collecting carbon dioxide using petro-coke desulfurization gypsum, the final by-product is used as a stimulus for blast furnace slag fine powder to increase activity, thereby replacing the most widely used common cement in construction work or minimizing the amount used.

Description

Binder composition using carbonate gypsum as a stimulant {BINDER COMPOSITION USING CARBONATED GYPSUM}

The present invention relates to a binder composition using carbonate gypsum as a stimulant, and more particularly, by mixing water with petro-coke desulfurization gypsum to perform a hydration reaction, and then collecting carbon dioxide and performing a mineral carbonation reaction to obtain a carbonate gypsum produced by blast furnace slag fine powder As a binder composition used as a stimulant, the carbonate gypsum enhances the activity of the granulated blast furnace slag powder to replace one type of common cement most widely used in construction work or to a binder composition that can minimize the amount used.

The emission of carbon dioxide during the production of type 1 ordinary cement is about 0.50 ton in the calcining step of limestone and about 0.40 ton in the calcination process through the combustion of fossil fuels. In the end, about 0.9 ton of carbon dioxide is emitted for every one ton of cement produced. . Therefore, greenhouse gas reduction will emerge as the biggest issue in the cement industry in the future.

Therefore, it is urgent to develop technology that can minimize the amount of cement used, and as a countermeasure, if the amount of cement can be minimized and a binder capable of exhibiting the same level of performance as cement can be manufactured using various industrial by-products, the production cost can be reduced. It is expected to be able to solve the problem of natural resource and energy depletion and environmental pollution caused by carbon dioxide emission as well as reduction.

As part of this, in order to provide a binder capable of exhibiting performance equivalent to cement using industrial by-products, Patent Document 1 includes petroleum coke combustion ash and By using desulfurization slag or desulfurization dust generated as a by-product of the desulfurization process in steelworks as a stimulus to increase the activity of blast furnace slag slag, a binder composition that can minimize the amount of one type of common cement most widely used in construction work is proposed. there is.

In addition, Patent Document 2 contains 10 to 500 parts by weight of petroleum coke combustion ash having a CaO content of 61 to 85% by weight, and a Na ₂ O content of 10 to 50% by weight and an SO ₃ content based on 100 parts by weight of blast furnace slag. A binder composition containing 0.1 to 50 parts by weight of sodium sulfate generated as a by-product in the sintering process or glass manufacturing process of 10 to 50% by weight and using a circulating resource having a specific surface area of 3,000 to 8,000 cm ² /g as a stimulus is proposed. .

Patent Document 3 relates to a binder composition for replacing cement using circulating resources as a stimulant, and bottom ash discharged from a coal-fired circulating fluidized bed boiler containing CaO and SO ₃ in fine powder of blast furnace slag and petro-coke desulfurization gypsum are used as stimulants Disclosed is a binder composition that can replace one type of common cement most widely used in construction work or minimize its amount by enhancing the activity of the fine powder of granulated blast furnace slag.

On the other hand, petro-coke desulfurization gypsum is discharged in the form of dry minerals from a circulating fluidized bed boiler that uses petro-coke generated as a by-product in the petroleum refining process as fuel. It is released as CaO and CaSO ₄ .

However, if it is used as a mineral carbonation reactant to capture carbon emitted during the petroleum refining process in the future, the main component is discharged in the form of wet minerals after going through a hydration reaction and a carbonation reaction with carbon dioxide.

When discharged in the form of wet carbonate minerals as described above, it is very advantageous in terms of carbon capture effect, but since there is no pure CaO component, it does not play a role as a dry cement mortar expansion material, which is the main recycling use. It is judged that there will be many difficulties in recycling.

Therefore, as a result of efforts to solve the conventional problems, the inventors of the present invention, when using conventional desulfurized gypsum as a stimulus, mix water with petrocoke desulfurized gypsum for a hydration reaction as an alternative to stopping production or minimizing use according to the future carbon neutrality. After that, carbon dioxide is collected to provide carbonate gypsum produced by the mineral carbonation reaction, and carbonate gypsum, which is difficult to recycle as an expansion material due to the absence of pure CaO, is used as a stimulus for blast furnace slag powder to increase the activity of the blast furnace slag powder. The present invention was completed by confirming that it could replace or minimize the use of the most widely used type 1 ordinary cement in construction.

Republic of Korea Patent No. 1525035 (2015.06.29. Notice) Republic of Korea Patent Publication No. 2016-004701 (2016.05.02. Publication) Republic of Korea Patent No. 1973093 (Announced on April 26, 2019)

An object of the present invention is to provide a binder composition that can replace one type of common cement most widely used in construction work by utilizing carbonate gypsum as a stimulant in blast furnace slag fine powder.

In order to solve the above technical problem, the binder composition using the carbonate gypsum as a stimulant according to the present invention is a carbonate gypsum 100 produced by mixing water with petro-coke desulfurization gypsum to perform a hydration reaction and then capturing carbon dioxide and performing a mineral carbonation reaction It contains 10 to 3,000 parts by weight of the blast furnace slag fine powder with respect to parts by weight.

In addition, the carbonate gypsum produced by the above reaction may contain sandy impurities, but the total composition contains 15 to 45% by weight of calcium carbonate, 25 to 50% by weight of gypsum, and 5 to 35% by weight of slaked lime as main components.

In addition, the carbonate gypsum is preferably used as it is in a wet form having a water content of 5 to 40% by weight or dried to a water content of less than 5% and then pulverized.

In addition, based on 100 parts by weight of the carbonate gypsum, it is preferable to further include 5 to 500 parts by weight of by-products of the steel mill sintering desulfurization process or circulating fluidized bed boiler desulfurization process having an SO ₃ content of 3 to 50% by weight.

In addition, 5 to 300 parts by weight of solid fuel combustion residues are further included with respect to 100 parts by weight of the carbonate gypsum, and the combustion residues are general solid fuel (SRF, Solid Refuse Fuel) or bio-solid fuel (BIO-SRF, Biomass-Solid It is desirable that it is emitted from a power plant that burns Refuse Fuel.

In addition, it further includes 5 to 300 parts by weight of cement based on 100 parts by weight of the carbonate gypsum, and the cement is any one selected from type 1 cement, semi-crude cement, early-strength cement, blast furnace slag cement, and fly ash cement, or a mixture of two or more. It is preferable to be

According to the present invention, by using carbonate gypsum, which is difficult to recycle, as a stimulus for the blast furnace slag fine powder, the binder composition can replace or minimize the amount of one type of common cement most widely used in construction work by enhancing the activity of the blast furnace slag fine powder. can provide.

In addition, it can reduce production costs by reducing the amount of cement used, as well as solve the problem of natural resource and energy depletion and environmental pollution caused by carbon dioxide emission at the same time.

Hereinafter, the present invention will be described in detail.

Hereinafter, a binder composition using carbonate gypsum as an irritant according to the present invention will be described in detail.

The present invention is characterized in that it comprises 10 to 3,000 parts by weight of blast furnace slag fine powder with respect to 100 parts by weight of carbonate gypsum produced by mixing water with petro-coke desulfurization gypsum to perform a hydration reaction and then capturing carbon dioxide and performing a mineral carbonation reaction.

The carbonate gypsum is a material that is discharged through a carbonation reaction after mixing water with desulfurized gypsum discharged in the form of dry minerals from a circulating fluidized bed boiler using petro-coke as a fuel, followed by a hydration reaction. The main components of petro-coke desulfurization gypsum are discharged as CaO and CaSO ₄ because limestone is mixed and burned with petro-coke during in-furnace desulfurization. However, when desulfurized gypsum is used as a mineral carbonation reactant to reduce carbon dioxide emissions in the future petroleum refining process, the main components are CaCO ₃ , CaSO ₄ , CaSO ₄ 2H ₂ O and Ca through a carbonation reaction with carbon dioxide through a hydration reaction. It is emitted in the form of wet minerals in the form of (OH) ₂ .

CaO and CaSO ₄ components present in desulfurized gypsum, which are combustion residues of circulating fluidized bed boilers, can also serve as stimulants for blast furnace slag fine powder, but carbonate gypsum discharged through carbonation reaction can also serve as stimulants for blast furnace slag fine powder. The CaCO ₃ component present in carbonate gypsum cannot play the role of stimulating blast furnace slag fine powder, but exists in a stable mineral form and fills the pores of the hardened body, and CaSO ₄ , CaSO ₄ 2H ₂ O and Ca(OH) ₂ The component plays a role of stimulation of blast furnace slag fine powder.

The blast furnace slag fine powder is a material obtained by pulverizing by-products obtained by quenching slag in a high-temperature molten state generated as a by-product in the steelmaking blast furnace process with water. When the blast furnace slag powder comes into contact with water, it forms an amorphous film and does not undergo a hydration reaction by itself, so the blast furnace slag powder is called latent hydraulic material. Therefore, when water is injected into the blast furnace slag fine powder, an amorphous film is formed on the surface, and elution of Ca ²⁺ and Al ³⁺ from the inside is not performed. However, OH ^- by Ca(OH) ₂ component present in carbonate gypsum and SO ₄ ^2- component by CaSO ₄ , CaSO ₄ 2H ₂ O component destroy the amorphous film of granulated blast furnace slag powder, causing Ca 2+ , Ca ²⁺ , Elution of Al ³⁺ is facilitated, and elution ions generate CaO-SiO ₂ -H ₂ O-based hydrates, etc., thereby rapidly accelerating hardening, and excess sulfur oxides are ettringite hydrate products having a needle-like structure. By generating (3CaO·Al ₂ O ₃ ·3CaSO ₄ ·32H ₂ O), the internal structure of the hydrated body can be densified and the compressive strength of the hardened body can be improved.

When the carbonate gypsum is discharged in the form of wet carbonate minerals, it is very advantageous in terms of carbon capture effect, but it does not have a pure CaO component, so it does not play a role as a dry cement mortar expansion material, which is the main recycling use. It is judged that there will be many difficulties in recycling. Therefore, it can be used by grinding after moisture drying and mixing with the blast furnace slag fine powder in the form of powder, or even if it is directly mixed with the blast furnace slag fine powder in the form of moisture, it can be used as a binder for secondary concrete products or a binder for fluidized filler.

The blast furnace slag fine powder can be used as long as it is a commercially available product having a specific surface area of 3,000 cm ² /g or more.

It is preferable that 10 to 3,000 parts by weight of the blast furnace slag fine powder is mixed with respect to 100 parts by weight of the carbonate gypsum. When the blast furnace slag fine powder is less than 10 parts by weight, the reaction of the blast furnace slag fine powder can be achieved by almost 100%, but the amount of carbonate gypsum is relatively excessive compared to the blast furnace slag fine powder, so that a large amount of unreacted carbonate gypsum exists, making it difficult to express strength. Conversely, when the weight exceeds 3,000, the stimulating effect of the carbonate gypsum is weak, so the initial strength is rapidly lowered, and an excess amount of slag that does not initiate a hydration reaction exists, and economical efficiency is also unfavorable.

In addition, the carbonate gypsum is produced by mixing water with desulfurized gypsum to perform a hydration reaction, and then capturing carbon _dioxide and performing a mineral carbonation reaction. It is characterized in that the composition contains 15 to 45% by weight of calcium carbonate, 25 to 50% by weight of gypsum and 5 to 35% by weight of slaked lime.

When the calcium carbonate component contained as the main component in the carbonate gypsum is less than 15% by weight, there is no carbon capture effect. As the components of gypsum and slaked lime, which will play the role, are rapidly reduced, it cannot be used as an irritant and can only serve as a filler as a non-reactive mineral.

As another main component, the gypsum component is preferably 25 to 50% by weight, more preferably a mixture of anhydrite and dihydrite, and at this time, anhydrite and dihydrate gypsum are preferably mixed in a weight ratio of 2: 1. When the gypsum component is less than 25% by weight, the strength is low, and when it exceeds 50% by weight, the calcium carbonate and slaked lime components are relatively reduced, resulting in a low pH and a decrease in the carbon dioxide capture effect.

The slaked lime component, which is another major component, is preferably 5 to 35% by weight. If the slaked lime component is less than 5% by weight, the pH is rapidly lowered and cannot function as an alkali stimulant, making it difficult to destroy the acidic film of the blast furnace slag fine powder in the early stage. When it exceeds 35% by weight, the carbon dioxide trapping effect is relatively rapidly lowered, and the gypsum component is relatively reduced, so the strength is rather lowered.

In addition, the carbonate gypsum is preferably used as it is in a wet form having a water content of 5 to 40% by weight or dried to a water content of less than 5% and then pulverized. It is possible to reduce drying costs when directly injected into secondary concrete products or fluidized fillers without a drying process. At this time, there is a disadvantage that drying and grinding costs increase when grinding to a moisture content of less than 5% by weight, but it can be put into a sieve, so it is possible to manufacture a binder in the form of powder at the factory and transport it in a bulk truck, so that only water can be poured at the construction site. there is

In addition, based on 100 parts by weight of the carbonate gypsum, it is preferable to further include 5 to 500 parts by weight of by-products of the steel mill sintering desulfurization process or circulating fluidized bed boiler desulfurization process having an SO ₃ content of 3 to 50% by weight. The by-product of the desulfurization process serves to enhance the strength by supplementing the sulfate stimulation effect of the blast furnace slag fine powder of the carbonate gypsum. When the content of SO ₃ is less than 3% by weight, there is no stimulation effect of the fine blast furnace slag powder, and when the content exceeds 50% by weight, a large amount of surplus SO ₃ component that does not react with the fine powder of blast furnace slag exists in a large amount, rather reducing the strength. It is preferable that 5 to 500 parts by weight of by-products from the steelworks sintering desulfurization process or circulating fluidized bed boiler desulfurization process are mixed with respect to 100 parts by weight of the carbonate gypsum. When the by-product of the desulfurization process is less than 5 parts by weight, the stimulation effect is insufficient, and on the contrary, when it exceeds 500 parts by weight, the amount of carbonate gypsum is relatively reduced, resulting in a decrease in strength.

In addition, 5 to 300 parts by weight of solid fuel combustion residues are further included with respect to 100 parts by weight of the carbonate gypsum, and the combustion residues are general solid fuel (SRF, Solid Refuse Fuel) or bio-solid fuel (BIO-SRF, Biomass-Solid It is desirable that it is emitted from a power plant that burns Refuse Fuel. The solid fuel combustion residue has CaO components, CaCl ₂ , NaCl, and KCl components to accelerate the hydration reaction of the blast furnace slag fine powder and to lower the freezing point in winter to prevent freezing and bursting. If the solid fuel combustion residue is less than 5 parts by weight with respect to 100 parts by weight of the carbonate gypsum, the effect of accelerating the hydration reaction is insufficient, and on the contrary, if it exceeds 300 parts by weight, the strength is rather lowered.

In addition, it further includes 5 to 300 parts by weight of cement based on 100 parts by weight of the carbonate gypsum, and the cement is any one selected from type 1 cement, semi-crude cement, early-strength cement, blast furnace slag cement, and fly ash cement, or a mixture of two or more. It is preferable to be The cement serves to increase the initial strength, and any product generally distributed on the market can be used. If the cement is less than 5 parts by weight with respect to 100 parts by weight of the carbonate gypsum, the initial strength enhancing effect is insufficient, and conversely, if it exceeds 300 parts by weight, hexavalent chromium may be eluted, and economical efficiency is also disadvantageous.

Preferred examples and comparative examples of the present invention will be described below. In addition, the following examples are intended to illustrate the present invention and should not be construed as limiting the scope of the present invention.

<Comparative example>

Based on 1 m ³ of sea clay, 400 kg of cement, 20 kg of bentonite, and 410 kg of water of type 1 were sufficiently mixed with a forced mixer to prepare a milk injection material, and homogeneously mixed with 1 m ³ of sea clay. It was cured at ℃ and the strength was measured at 3 days, 7 days, and 28 days. The coefficient of permeability was conducted before measuring the compressive strength at the age of 7 days.

<Example 1>

Instead of the type 1 cement of the comparative example, the petro-coke desulfurized gypsum was wet-processed, carbonated by injecting carbon dioxide, and the discharged carbonate gypsum was dried to a moisture content of 1% or less, and then pulverized to adjust the specific surface area to 3,560 cm ² /g. . The main components of the carbonate gypsum were 29.6% by weight of CaCO ₃ , 24.2% by weight of CaSO ₄ , 17.6% by weight of CaSO ₄ 2H ₂ O and 18.2% by weight of Ca(OH) ₂ . A binder was prepared by homogeneously mixing 150 parts by weight of the blast furnace slag fine powder with respect to 100 parts by weight of the carbonate gypsum.

Based on 1 m ³ of sea clay, 400 kg of the binder and 410 kg of water were sufficiently mixed with a forced mixer to prepare a milk injection material, and homogeneously mixed with 1 m ³ of sea clay. The strength was measured on the 3rd, 7th, and 28th days of age. The coefficient of permeability was conducted before measuring the compressive strength at the age of 7 days.

<Example 2>

Based on 100 parts by weight of the carbonate gypsum prepared in the same way as in Example 1 instead of the type 1 cement of the comparative example, 150 parts by weight of blast furnace slag fine powder, circulating fluidized bed boiler combustion residue 50 of burning coal having an SO ₃ content of 8.2% by weight A binder was prepared by homogeneously mixing parts by weight.

Based on 1 m ³ of sea clay, 400 kg of the binder and 410 kg of water were sufficiently mixed with a forced mixer to prepare a milk injection material, and homogeneously mixed with 1 m ³ of sea clay. The strength was measured on the 3rd, 7th, and 28th days of age. The coefficient of permeability was conducted before measuring the compressive strength at the age of 7 days.

<Example 3>

Based on 100 parts by weight of the carbonate gypsum prepared in the same way as in Example 1 instead of the type 1 cement of the comparative example, 150 parts by weight of blast furnace slag fine powder, circulating fluidized bed boiler combustion residue 50 of burning coal having an SO ₃ content of 8.2% by weight A binder was prepared by homogeneously mixing parts by weight and 20 parts by weight of wood chip solid fuel combustion residue.

Based on 1 m ³ of sea clay, 400 kg of the binder and 410 kg of water were sufficiently mixed with a forced mixer to prepare a milk injection material, and homogeneously mixed with 1 m ³ of sea clay. The strength was measured on the 3rd, 7th, and 28th days of age. The coefficient of permeability was conducted before measuring the compressive strength at the age of 7 days.

<Example 4>

A binder was prepared by homogeneously mixing 150 parts by weight of blast furnace slag fine powder and 50 parts by weight of Type 1 cement with respect to 100 parts by weight of the carbonate gypsum prepared in the same manner as in Example 1 instead of the Type 1 cement of the comparative example.

Based on 1 m ³ of sea clay, 400 kg of the binder and 410 kg of water were sufficiently mixed with a forced mixer to prepare a milk injection material, and homogeneously mixed with 1 m ³ of sea clay. The strength was measured on the 3rd, 7th, and 28th days of age. The coefficient of permeability was conducted before measuring the compressive strength at the age of 7 days.

<Experiment> Test method and result of specimen

As shown in Table 1 below, the permeability coefficient was conducted according to the KS F 2322 variable permeability test method, and the compressive strength test was conducted according to the KS F 2343 uniaxial compressive strength test method. The heavy metal dissolution test was conducted after measuring the compressive strength on the 28th.

(1) Permeability coefficient

Table 2 shows the permeability test results of the specimens cured at 20 ° C for 7 days.

As can be seen from Table 2, satisfactory results were obtained by constructing an impermeable layer in all specimens, and it can be seen that the permeability coefficient of the examples of the present invention is lower than that of the comparative examples, which is In the case of the binder, the volumetric shrinkage that occurs during the hydration reaction and the moisture contained in the specimen is evaporated or hydrated, resulting in a relatively high permeability coefficient. It is judged that it shows relatively low water permeability because the tissue is dense due to the chemical prestress action by causing expansion in the state of being restrained by the lingite.

(2) Change in uniaxial compressive strength

Table 2 shows the uniaxial compressive strength of Comparative Example and Examples 1 to 4. As can be seen from this, Example 1 using carbonate gypsum and blast furnace slag fine powder developed almost the same strength as Comparative Example 1 using 1 type cement, and Example 2 and coal further containing circulating fluidized bed boiler combustion residues It can be seen that Example 3, which further includes combustion circulating fluidized bed boiler combustion residues and solid fuel combustion residues, exhibits higher strength than Comparative Examples using only 1 type cement at all ages. In addition, it was confirmed that Example 4, in which cement was further included, exhibited superior strength compared to the comparative example not only at the initial strength but also at the age of 28 days.

Therefore, it was found that the binder of the present invention can exhibit performance capable of replacing type 1 cement.

(3) Heavy metal elution test

Looking at the results of the heavy metal elution test in Table 3, in the case of Comparative Example, the acceptable standard was satisfied, but in the case of hexavalent chromium, an amount exceeding 50% of the standard value was eluted. However, most heavy metals as well as hexavalent chromium were not detected in all examples of the present invention.

Therefore, the binder of the present invention utilizes petrocoke desulfurization gypsum, which is produced in large quantities in the petroleum refining process, and carbonate gypsum generated by the carbonation reaction of carbon dioxide as a stimulant to enhance the activity of blast furnace slag fine powder, thereby making it one of the most widely used types in construction work. Ordinary cement can be substituted or its amount can be minimized. In addition, it can reduce production costs by reducing the amount of cement used, as well as solve the problem of natural resource and energy depletion and environmental pollution caused by carbon dioxide emission at the same time.

Although the present invention has been described in detail only with respect to the specific embodiments described above, it is obvious to those skilled in the art that various changes and modifications are possible within the scope of the technical idea of the present invention, and it is natural that such changes and modifications fall within the scope of the appended claims.

Claims (6)

Based on 100 parts by weight of carbonate gypsum, including 10 to 3,000 parts by weight of blast furnace slag fine powder,
The binder composition, characterized in that the carbonate gypsum is produced by mineral carbonation reaction by mixing water with petro-coke desulfurization gypsum to perform a hydration reaction and then capture carbon dioxide. The binder composition according to claim 1, characterized in that the total composition of the carbonate gypsum contains 15 to 45% by weight of calcium carbonate, 25 to 50% by weight of gypsum, and 5 to 35% by weight of slaked lime as main components. The binder composition according to claim 1, wherein the carbonate gypsum is used as it is in a wet form with a moisture content of 5 to 40% by weight or dried to a moisture content of less than 5% and then pulverized. The binder composition according to claim 1, further comprising 5 to 500 parts by weight of a by-product of a steel mill sintering desulfurization process or a circulating fluidized bed boiler desulfurization process having an SO ₃ content of 3 to 50% by weight based on 100 parts by weight of the carbonate gypsum. . The method of claim 1, further comprising 5 to 300 parts by weight of solid fuel combustion residue with respect to 100 parts by weight of the carbonate gypsum, and the combustion residue is general solid fuel (SRF, Solid Refuse Fuel) or bio solid fuel (BIO- A binder composition characterized in that it is discharged from a power plant that burns SRF, Biomass-Solid Refuse Fuel). The method of claim 1, further comprising 5 to 300 parts by weight of cement based on 100 parts by weight of the carbonate gypsum, wherein the cement is any one selected from type 1 cement, semi-crude cement, early steel cement, blast furnace slag cement, and fly ash cement. A binder composition, characterized in that one or a mixture of two or more.