KR20220138954A - Photassium chloride plain concrete alkali activator extracted from chlorine bypass dust generated in cement manufacturing process and the plain concrete composition comprising them and inorgarnic artificial marble using them - Google Patents

Abstract

The present invention relates to a potassium chloride plain concrete activator extracted from chlorine bypass dust generated in a cement manufacturing process, a plain concrete composition including the same, and an inorganic artificial marble using the same. More specifically, potassium chloride extracted from chlorine bypass dust generated in a cement manufacturing process is used as an alkali activator in a mixture of cement and blast furnace slag fine powder or fly ash, or used as an alkali activator in blast furnace slag fine powder or fly ash fine powder such that the amount of cement used can be reduced and the initial hydration activity and setting of plain concrete can be promoted.

Description

Potassium chloride plain concrete alkali activator extracted from chlorine bypass dust generated in cement manufacturing process and the plain concrete composition comprising them and inorgarnic artificial marble using them}

The present invention relates to a potassium chloride-free concrete stimulant extracted from chlorine bypass dust generated in a cement manufacturing process, a root-free concrete composition comprising the same, and inorganic artificial marble using the same, and more particularly, to Potassium chloride extracted from pass dust is used as an alkali stimulant in a mixture of cement and fine powder of blast furnace slag or fly ash, or as an alkali stimulant in fine powder of blast furnace slag or fine fly ash to reduce cement usage, initial hydration activity and coagulation of unrooted concrete mortar It relates to a potassium chloride-free concrete stimulant extracted from chlorine bypass dust generated in the cement manufacturing process, a root-free concrete composition comprising the same, and inorganic artificial marble using the same.

The development of concrete-based construction technology has led to the rapid industrial development and the construction of high-tech infrastructure related to housing, and concrete is used as an essential material in construction.

Cement, the main material of such concrete, generates carbon dioxide due to chemical decomposition during the firing process using high temperature, and it is reported that about 0.8 tons of carbon dioxide is emitted when 1 ton of cement is manufactured.

In addition, it has been reported that carbon dioxide emissions from the cement industry account for 8% of global emissions. is proceeding with

As a technology development to reduce the amount of cement used, a number of technological developments using industrial by-products having hydraulic reactivity as substitutes have been carried out, and technology development using blast furnace slag and fly ash, which are representative industrial by-products, is mainly.

This technology development is for hydration activation of industrial by-products using alkali components from cement, and it has also been reported that the use of alkali stimulants can forcefully destroy the coating of industrial by-product particles, leading to a high hydration reaction.

In addition, in the technical development of alkali stimulatory activity, various technologies have been developed for cement using strong alkali reagents such as Ca(OH) ₂ , NaOH and KOH, and alkali stimulants are added to the mixture of industrial by-products and cement-based raw materials. The development of technology to increase the strength by utilizing it is also in progress.

However, alkali stimulant cement requires the use of an expensive alkali stimulant, and for this reason, it is disadvantageous in terms of performance and economics compared to formulations using Portland cement, so there are concerns about practical use.

On the other hand, the cement process has an optimal environment for safely processing plastics. However, since plastics with a high chlorine content such as PVC increase the chlorine content in the clinker, a chlorine release process must be installed to prevent this.

The waste generated in the chlorine discharging process is called Chlorine Bypass Dust. Chlorine Bypass Dust contains K, Cl, Ca, etc. as main components, and is being disposed of in landfill at a great cost.

Techniques for recycling such Chlorine Bypass Dust without landfill treatment have been developed. Korean Patent Application Laid-Open No. 10-2014-0107808 (published on September 05, 2014) discloses raw material fine dust generated from the exhaust gas extracted during the cement manufacturing process. providing; mixing the raw material fine dust and hot water; injecting a carbon dioxide gas source into the mixed water; filtering the precipitate in the mixed water that has undergone the injection step; and drying the filtered solution. A method has been developed in which KCl, a chlorine compound, is recovered from fine dust in the cement manufacturing process, and the remaining by-product, the dehydrated cake, can be reused as a raw material for cement.

In addition, Korea Patent No. 10-1561637 (registration date October 13, 2015) discloses the steps of providing chlorine bypass dust generated from the exhaust gas extracted during the cement manufacturing process; preparing a slurry by mixing the chlorine bypass dust, an acidic aqueous solution and gypsum powder; injecting carbon dioxide into the mixed slurry; a first filtering step of filtering the slurry that has passed through the injection step using a filtering device; removing heavy metals by injecting carbon dioxide back into the filtrate of the first filtration step; a second filtering step of filtering the solids generated in the heavy metal removal step using a filtering device; cooling to remove sodium and sulfate ions in the filtrate of the second filtration step; and drying the filtrate from which the sodium and sulfate ions have been removed, as a recovery method of potassium chloride from chlorine bypass dust, wherein the recovered potassium chloride is recycled to industries using potassium chloride, such as industrial raw materials such as fertilizers or snow removal agents. technology has been developed.

In addition, Korean Patent No. 10-1968111 (registration date April 05, 2019) discloses the steps of adding cement bypass dust and mixed water in a weight ratio of 1:3 and stirring for 20 to 30 minutes to prepare a slurry; a first heavy metal removal step of leaching heavy metals by adding a first heavy metal removal agent to the slurry; separating the slurry into a first supernatant and a first sludge, and storing the first supernatant in a post tank; an impurity removal step of leaching impurities contained in the first supernatant by introducing an impurity removing agent into the post tank; After the impurity removal step, any one of H ₂ O ₂ , NaOCl and K ₂ CO ₃ is added to the first supernatant and maintained for 10 hours as a second heavy metal remover to leach the remaining heavy metals contained in the first supernatant. secondary heavy metal removal step; separating the material generated after the second heavy metal removal step into a second supernatant and a second sludge, and storing the second supernatant in a filtrate tank; calculating potassium chloride crystals by vacuum evaporation of the second supernatant; centrifuging the potassium chloride crystals and solution generated in the calculating step, transferring the potassium chloride crystals to a dryer, and re-inputting the solution into the vacuum evaporation equipment to re-calculate potassium chloride crystals; and drying the potassium chloride crystals to produce potassium chloride. A method for producing potassium chloride using cement bypass dust, wherein the recovered KCl is used for general use, and the sludge generated after recovering potassium chloride is used for manufacturing cement clinker. This has been known.

In addition, Korean Patent No. 10-2094398 (registration date March 23, 2020) discloses a recycling method of chlorine bypass dust (CBD) discharged from a kiln during the cement manufacturing process, (a) mixing CBD with water to create a CBD slurry After preparing the CBD slurry, mixing an inorganic acid to produce a mixture; (b) further adding an organic acid to the mixture to produce a reaction mixture for reacting the CBD with the inorganic acid and the organic acid; (c) stepwise raising the pH of the reaction mixture to 4 by adding an alkaline compound to the reaction mixture; (d) a first solid-liquid separation step of further stirring the reaction mixture in a pH range of 4 to 4.5 for 0.5 hours or more and then solid-liquid separation of the reaction mixture; (e) adding an alkaline compound to the filtrate obtained in the first solid-liquid separation to raise the pH of the filtrate to 7 to 10.5 and stirring for 2 hours or more, adding sodium sulfide to the filtrate and stirring for 1 hour or more and lowering the pH of the filtrate to 6.5 to 7.5, adding an anionic polymer flocculant to the filtrate and performing a second solid-liquid separation to obtain a solid sludge enriched with lead-containing heavy metals and a filtrate enriched with potassium chloride 2 solid-liquid separation step; And (f) after concentrating the filtrate, cooling to room temperature to precipitate crystallization, or re-injecting the filtrate in step (a) to increase the concentration to a saturated solution or higher, and then crystallize and precipitate it to recover KCl As a recycling method comprising a, the recovered KCl is used for general use, and the dechlorinated sludge containing gypsum from which heavy metals such as chlorine and lead have been removed as a main component is a known technology that can be recycled as a raw material for cement clinker.

In addition, in Non-Patent Documents 1 and 2 of the prior art documents, methods for extracting and separating K and Cl ions, which are difficult to use in the cement process, in the form of KCl through a cation extraction method are known.

However, in the prior art, the recovered potassium chloride is used for general purposes as industrial raw materials such as fertilizers or snow removal agents, and the remaining gypsum or dechlorinated sludge can be recycled as cement raw materials, and the recovered potassium chloride unrooted concrete mortar is used. The technology used as an alkali stimulant to promote setting or hydration activity is not recognized at all. Or, the technology used as an alkali stimulant for promoting hydration activity has never been developed at home or abroad.

Accordingly, the present inventors, in order to develop a method of utilizing KCl separated as described above, according to a study on the use of reagent grade KCl as a building material, the use of KCl promotes setting by increasing the initial cement hydration heat, and Based on the reported properties as an irritant to increase compressive strength, a large amount of Cl causes corrosion of reinforcing bars when used in reinforced concrete. As a result of measuring the strength of KCl separated from chlorine bypass dust (CBD) and mortar including cement and cementless material or cementless material, compared with the existing alkali irritants such as NaOH and KOH, as above, the chlorine bypass It was confirmed that KCl isolated from dust (CBD) can be used as an effective alkali irritant.

In addition, since it is important to secure initial strength to secure handling strength after demolding in the inorganic artificial marble manufacturing process, potassium chloride recovered from the chlorine bypass dust (CBD) is applied to the concrete artificial marble manufacturing process, which is a part of the unrooted concrete product. It was confirmed that handling strength can be secured through promotion of initial hydration activity, and the present invention was completed.

[Patent Document 001] Korea Patent Publication 10-2014-0107808 (published on September 05, 2014) [Patent Document 002] Korea Registered Patent 10-1561637 (Registration Date October 13, 2015) [Patent Document 003] Korean Patent Registration 10-1968111 (Registration Date April 05, 2019) [Patent Document 004] Korean Patent 10-2094398 (Registration Date March 23, 2020)

[Non-Patent Document 001] Ye-Hwan Lee, Dong-Hee Han, Sang-Moon Lee, Han-Ki Eom and Sung-Su Kim, A Study on the Cation Extraction and Separation in Cement Industrial By-products for Applications to the Carbonation Process, Applied chemistry for engineering, Vol. 30, No. 1, pp. 34-38, 2019. [Non-Patent Document 002] Younghee Jang, Ye-Hwan Lee, Jiyu Kim, Il-Gun Park, Je-Yeol Lee, Byung-Hyun Park, Sang-Moon Lee, Sung-Su Kim, A study on the optimization of Ion Exchange Resin operating condition for removal of KCl from CKD extract, Journal of the Korean Applied Science and Technology, Vol. 36, No. 4, pp. 1088-1095, 2019.

The present invention is to solve the above problems, and potassium chloride extracted from chlorine bypass dust generated in the cement manufacturing process is used as an alkali stimulant in a mixture of cement and blast furnace slag fine powder or fly ash, or blast furnace slag fine powder or fly ash. Potassium chloride-free concrete stimulant extracted from chlorine bypass dust generated in the cement manufacturing process, which can be used as an alkali stimulant in fine ash powder to reduce the amount of cement used, and promote the initial hydration activity and setting of the unrooted concrete mortar An object to be solved is to provide a concrete composition and inorganic artificial marble using the same.

In order to solve the above problems, the present invention uses potassium chloride extracted from chlorine bypass dust generated in the cement manufacturing process as an alkali stimulant in a mixture of cement and blast furnace slag fine powder or fly ash, or alkali to fine blast furnace slag powder or fly ash powder. Potassium chloride rooted concrete stimulant extracted from chlorine bypass dust generated in the cement manufacturing process, which can be used as a stimulant to reduce the amount of cement used, and to promote the initial hydration activity and setting of unrooted concrete, is a solution to the problem.

Potassium chloride extracted from the chlorine bypass dust is mixed with cement and fine powder of blast furnace slag or a mixture of fly ash at 10% by weight, or mixed with fine powder of blast furnace slag or fine fly ash at 10% by weight as a means of solving the problem.

Potassium chloride extracted from the chlorine bypass dust is a KCl solution mixed with water at a concentration of 150-200 g/L with a purity of 95% as a means of solving the problem.

Potassium chloride extracted from the chlorine bypass dust is a KCl solution obtained by mixing Chlorine Bypass Dust with water at a concentration of 400 g / ℓ, stirring with a magnetic stirrer, and filtering residual solids with a GF / C filter. do it by means

In addition, potassium chloride extracted from chlorine bypass dust generated in the cement manufacturing process is mixed and used as an alkali stimulant in a mixture of cement and fine blast furnace slag powder or fly ash, or a root-free concrete composition using fine blast furnace slag powder or fly ash as an alkali stimulant as a means of solving the problem.

The unrooted concrete composition exhibits setting properties within 24 hours when used in fine blast furnace slag powder or fly ash without self-reactivity, and when used in fine blast furnace slag powder or fly ash, shows a compressive strength of 20 MPa or more at 28 days of age, cement When used for blast furnace slag fine powder or a mixture of fly ash, it should show setting characteristics within 4 hours and compressive strength at 28 days of age of 55 to 60 MPa as a means to solve the problem.

When the unrooted concrete composition is cured in water, hydrocalumite, one of Friedel's salts, is produced, and when cured in an autoclave condition at a temperature of 180° C., hydrocalumite is decomposed as a means of solving the problem.

In addition, the present invention dehydrates the water binder ratio to less than 20% by pressing the unrooted concrete composition for 5 to 10 minutes with a pressing force of 100 MPa in the dehydration and pressurization process of the artificial marble manufacturing process. A method for producing inorganic artificial marble that exhibits high strength of 100 MPa or more by curing it for 8 hours or more by high-temperature and high-pressure curing at 180° C. and 10 atmospheres is a solution to the problem.

In addition, the present invention makes the inorganic artificial marble manufactured according to the method for manufacturing the inorganic artificial marble as a means of solving the problem.

Potassium chloride-free concrete stimulant extracted from chlorine bypass dust generated in the cement manufacturing process according to the present invention, a root-free concrete composition comprising the same, and inorganic artificial marble using the same are obtained by mixing potassium chloride extracted from chlorine bypass dust generated in the cement manufacturing process with cement. When used as an alkali stimulant for fine blast furnace slag powder or fly ash mixture, or as an alkali stimulant for fine blast furnace slag powder or fly ash fine powder, it has excellent effects in reducing the amount of cement used, and promoting the initial hydration activity and setting of concrete mortar. have.

In addition, when the unrooted concrete composition is applied to the artificial marble manufacturing process, it is possible to secure handling strength after demolding before curing of the artificial marble through the promotion of initial hydration.

1 is a graph showing the mineral composition of Chlorine Bypss Dust and KCl extracted
Figure 2 is a graph showing the flow of mortar using KCl derived from cement as a stimulant
3 is a coagulation test result of a paste using KCl derived from cement by-products as an irritant.
4 shows the compressive strength of an OPC 100% mortar test specimen without using an irritant, and a specimen using 100% BFs as a binder and an irritant.
Figure 5 shows the OPC 100% mortar test specimen without using an irritant, and the compressive strength of the specimen using an irritant after mixing 50% of OPC and a mineral admixture as a binder.
6 is a graph showing the contribution rate to the strength when 50% of OPC and mineral admixture are mixed and the test specimen not using an irritant is set as plaine, and each stimulant is used compared to that by age and curing condition
7 is a graph of mineral analysis results of specimens using 50% each of BFs and OPC;
8 is a graph of mineral analysis results of specimens using FA and OPC 50% each.
9 is an image of inorganic artificial marble produced by securing initial demolding strength and handling strength with a mortar using cement-derived KCl as a stimulant.

According to the present invention, potassium chloride extracted from chlorine bypass dust generated in the cement manufacturing process is used as an alkali stimulant in a mixture of cement and fine powder of blast furnace slag or fly ash, or as an alkali stimulant in fine powder of blast furnace slag or fly ash. Potassium chloride-free concrete stimulant extracted from chlorine bypass dust generated in the cement manufacturing process, which can reduce

Potassium chloride extracted from the chlorine bypass dust is mixed with cement and fine powder of blast furnace slag or a mixture of fly ash at 10% by weight, or mixed with fine powder of blast furnace slag or fine fly ash at 10% by weight.

The potassium chloride extracted from the chlorine bypass dust is characterized in that it is a KCl solution mixed with water at a concentration of 150-200 g/L with a purity of 95%.

Potassium chloride extracted from the chlorine bypass dust is a KCl solution obtained by mixing Chlorine Bypass Dust with water at a concentration of 400 g / ℓ, stirring with a magnetic stirrer, and filtering residual solids with a GF / C filter. characterized.

In addition, potassium chloride extracted from chlorine bypass dust generated in the cement manufacturing process is mixed and used as an alkali stimulant in a mixture of cement and fine blast furnace slag powder or fly ash, or a root-free concrete composition using fine blast furnace slag powder or fly ash as an alkali stimulant is a characteristic of the technical composition.

The unrooted concrete composition exhibits setting properties within 24 hours when used in fine blast furnace slag powder or fly ash without self-reactivity, and when used in fine blast furnace slag powder or fly ash, shows a compressive strength of 20 MPa or more at 28 days of age, cement When used in the mixture of blast furnace slag fine powder or fly ash, it exhibits setting characteristics within 4 hours, and the compressive strength at 28 days of age is 55 to 60 MPa.

When the unrooted concrete composition is cured in water, hydrocalumite, one of Friedel's salts, is produced, and when it is cured in an autoclave condition at a temperature of 180° C., hydrocalumite is decomposed.

In addition, the present invention dehydrates the water binder ratio to less than 20% by pressing the unrooted concrete composition for 5 to 10 minutes with a pressing force of 100 MPa in the dehydration and pressurization process of the artificial marble manufacturing process. A method of manufacturing inorganic artificial marble that exhibits high strength of 100 MPa or more by curing it for 8 hours or more by high-temperature and high-pressure curing at 180° C. and 10 atmospheres is characterized by the technical configuration.

In addition, the present invention is characterized in the technical configuration of the inorganic artificial marble manufactured according to the method for manufacturing the inorganic artificial marble.

Hereinafter, embodiments and drawings of the present invention will be described in detail so that those of ordinary skill in the art can easily carry out the present invention. However, the present invention may be embodied in several different forms, and is not limited to the embodiments and drawings described herein.

[Experiment plan]

The experimental plan is as shown in [Table 1], and the binders used are ordinary Portland cement (OPC), which is the standard, and Ground Granulated Blast Furnace Slag (hereinafter referred to as BFs) and fly ash, which are representative latent hydraulic industrial by-products. , FA) was used.

The replacement rates of blast furnace slag and fly ash were set as 0, 50, and 100% compared to cement, and the effect of alkali stimulants according to the presence or absence of cement was analyzed.

The alkali irritant used in the experiment was NaOH, KOH, and liquid KCl separated from Chlorine Bypass Dust.

The amount of alkali stimulant added is 10% based on the mass of the blast furnace slag or fly ash, and the liquid KCl was added after checking the concentration through precipitation and drying, and then calculating the amount added.

The curing method for the mortar was divided into underwater curing and autoclave curing at a temperature of 180°C.

The experimental formulation is as shown in [Table 2], and the water-binding material ratio is 40% and the air content is 5% to calculate the formulation.

For experimental measurement items, coagulation was measured for the paste, flow of mortar, flexural strength, compressive strength, and mineral composition of hydrate at 28 days of age were measured.

[Materials used]

The binder used in the experiment was 'H' type 1 Ordinary Portland Cement (OPC), 'S' type 3 blast furnace slag fine powder (BFs), and 'E' power company type 2 fly ash (FA). The fineness of each binder was 3,818 cm2/g for OPC, 4,356 cm2/g for blast furnace slag, and 3,051 cm2/g for fly ash.

[Table 3] shows the chemical composition of the used binder and Chlorine Bypass Dust. The alkali irritants used were reagent grade NaOH and KOH as comparison objects.

[Figure 1] shows the mineral composition of Chlorine Bypss Dust and KCl extracted. While Chlorine Bypss Dust contains CaO including Ca ions, it can be seen that most of the extracted KCl shows the peak of KCl minerals.

For selective separation of KCl, water added with alkali solvent and Chlorine Bypass Dust were mixed at a ratio of 400g/ℓ, stirred with a magnetic stirrer, and the solution and solids were separated using a GF/C filter.

At this time, the pH of the solution was 12.7 and the purity of KCl was 95% or more, and the confirmed concentration was 193 g/ℓ, calculated as a solid amount, and the main ions of the solution were K and Cl. Included.

[Test Methods]

Coagulation using paste was carried out at a temperature of 20±2℃ and relative humidity of 60±5% in accordance with 'L ISO 9597 Cement Coagulation and Stability Test Method'. Then, the experiment was conducted by dissolving the alkali irritant.

The flow of the mortar was tested with a specified flow table in accordance with 'Testing method for compressive strength of L 5105 hydraulic cement mortar', and the diameter was measured after dropping the table 25 times for 15 seconds.

The production and measurement of the mortar compressive strength test specimen was carried out according to the 'L ISO 679 cement strength test method', and the specimen for compressive strength and hydrate measurement was cured by underwater curing and autoclave curing.

The specimen was cured in a constant temperature and humidity room at 20±2℃ and relative humidity of 60±5% until 1 day of age, then demolded and cured in water at a temperature of 20℃. The strength was measured after curing for 8 hours at ℃ 10 atm.

The composition analysis of hydration minerals at the age of 28 days by curing method was measured using an X-Ray Diffractometer.

[Mortar Flo]

[Figure 2] is a graph showing the flow of mortar using KCl derived from cement as a stimulant. In the experiment, each stimulant was added to the mixing water and used in a dissolved state. Accordingly, the liquid was increased by adding the mixing water and the dissolved irritant. The flow result of the mortar did not affect the fluidity according to the use of the stimulant, and it was found that all formulations satisfied the range of 185±15mm with the use of the high-performance water reducing agent.

However, due to the difference in fineness, the amount of high-performance water reducing agent required for the FA formulation was small, and the amount of high-performance water reducing agent used for the BFs formulation was relatively high. Since each stimulant was added rather than a substitute for the compounding water and binder, the amount of liquid substances that could affect the flow of the mortar increased, but as the stimulant was dissolved, the viscosity of the compounding water increased and there was no difference in fluidity. is judged

[Paste Condensation]

[Fig. 3] shows the results of the coagulation experiment of the paste using KCl derived from cement by-products as an irritant. The paste experiment was also used by mixing 10% of the mass of the mineral admixture as in the mortar experiment. Among the formulations using 100% mineral admixture, in the case of BFs formulation, NaOH and KOH addition formulation showed faster setting than OPC formulation with termination within 3 hours, and KCl addition formulation showed a termination time of 15 hours and 37 minutes.

The FA formulation did not show termination within 24 hours in the case of the formulation using NaOH, the termination at 8 hours 53 minutes in the case of KOH, and 17 hours and 17 minutes in the case of the use of KCl. In the case of using KCl, the cement mixture using mineral admixtures also showed the properties of an irritant to cause coagulation, but when cement was not used, it was shown to show a termination time of 10 hours or more.

However, unlike KOH and NaOH, which show a high accelerating effect in BFs with high hydration activity due to their latent hydraulic properties, the accelerating effect is greatly reduced in FA, it is considered encouraging that KCl exhibits the same accelerating effect in FA.

In particular, in FA, when NaOH was used, no termination was seen even within 16 hours, so it was confirmed that KCl derived from cement by-products exhibited a better effect as an alkali stimulant.

When NaOH and KOH were used in a binder mixed with OPC and mineral admixture by 50%, respectively, it showed a fast setting time of about 1 hour regardless of the composition of the binder. When KCl was added, the FA formulation showed a somewhat slower termination of 5 hours and 37 minutes than the OPC 100% formulation, and the BFs formulation showed a faster completion of 4 hours and 10 minutes than OPC.

This is because KCl has a relatively low pH compared to NaOH and KOH, so the initial irritation is lower, but even in the case of KCl, it is judged that it promotes coagulation by stimulating cement alite and interstitial minerals due to high alkali properties of pH 12 or higher and salt. The possibility of use as an irritant when using mineral admixtures was confirmed.

[Mortar Compressive Strength]

[Fig. 4] shows the compressive strength according to the curing conditions and age of the OPC 100% mortar specimen without the use of an irritant, and the mortar specimen using 100% BFs as a binder and NaOH, KOH, and KCl derived from cement as the stimulant. As shown, the strength expression ratio of each specimen compared to the strength of the OPC 100% specimen is shown along the auxiliary axis as hydration activity.

The specimen using 100% FA did not express the demolding strength of 1 MPa or more even by the 28th day of age even with the use of an alkali stimulant, so it was excluded from [FIG. 4]. This is because the fly ash used has a Fe ₂ O ₃ content of more than 11%, and the two types of powder are 3,051 cm ² /g, and as the 45㎛ sieve residual content is 40% or less according to the KS F 5405 standard, a large amount of inert particles It is judged that the hydration reaction by alkali irritants was not activated.

In the case of a mortar specimen using 100% BFs as a binder, different strengths were expressed depending on the type of irritant, and when NaOH and KOH were used as stimulants as of 28 days of age, a compressive strength of 30 MPa or more was shown. Although this value is lower than the OPC formulation having a compressive strength of 46 MPa at the age of 28 days, it is judged that it is the result of confirming the possibility of using it alone enough to express a hydration activity of 65% or more with cementless formulation as a latent hydraulic binder.

In addition, in the case of specimens subjected to autoclave curing instead of in water curing, the hydration activity was better than that of the underwater curing specimens. Higher performance compared to OPC can be expected when applied as a cementless binder in the manufacturing process of precast concrete products.

However, in the test specimen using cement-derived KCl as an irritant in expectation of performance equivalent to the above, the expected results were not obtained. Although the strength expression was confirmed as cementless by using a stimulant, it was only 50% compared to OPC, and as confirmed in the condensation test result of [Fig.

[Fig. 5] is a comparison of the compressive strength of a mortar specimen of 100% OPC without using an irritant and a mortar specimen using 50% of OPC and a mineral admixture as a binder. The hydration activity was compared. The mineral admixture mixed with OPC was compared by dividing compressive strength and hydration activity with BFs and FA.

Considering that the specimen using 100% mineral admixture did not express even 1 MPa of demolding strength until 28 days of age in the case of FA, it can be confirmed that a certain strength is expressed in the case of mixed use with OPC.

In particular, 50% or more of OPC is mixed with OPC to express more than 50% of hydration activity compared to OPC at all ages even without the use of a stimulant, and it can be seen that the activity increases up to 60% as the age increases.

It is possible to act as a sufficient stimulant by the generation of CH that occurs in the hydration process of OPC, and it works more effectively with long-term age. In addition, since FA has a high content of amorphous Si, it is considered that the strength expression through the generation of tobermorite through the hydrothermal synthesis process through autoclave curing may have contributed in part.

Therefore, in the case of FA specimen, the strength ratio of 28 days of age compared to the BFs mixed specimen in the aquatic curing specimen is 69%, 69%, 51%, and 67% in the order of None, NaOH, KOH, KCl, whereas in the case of autoclave curing, 81% , 110%, 75%, and 88%, catching up with the strength expression rates of BFs.

When a mineral admixture is used alone, it does not have reactivity due to latent hydraulic properties when no irritant is used. However, when mixed with OPC, mineral admixture can also develop strength due to the stimulation of CH generated during OPC hydration. More than 50% hydration activity can be confirmed.

BFs50 specimens were also confirmed to express more than 100% hydration activity compared to OPC at 28 days of age. However, rather, it can be seen that the strength decreases in the specimens using NaOH and KOH as stimulants. Theoretically, as OPC produces approximately 20-25% Ca(OH) ₂ during a sufficient hydration reaction with water, it is judged that the additionally added stimulant adversely affects strength development due to an excess of alkali.

In addition, in the case of NaOH and KOH, it stimulates the reactivity of the mineral admixture and contributes to strength expression, but it is judged that minerals such as ethrinzite generated by hydration of OPC at high pH show instability.

On the other hand, KCl shows a higher strength than the specimen using NaOH and KOH, and even higher than that of the OPC100% specimen, with the opposite tendency to the case of using the mineral admixture alone. In particular, it can be seen that the specimen using KCl in the specimen mixed with blast furnace slag with OPC exceeds 100% of hydration activity at all ages, and expression up to 127% at 28 days of age. Because it does not have a high pH of NaOH and KOH levels, it is judged that it does not affect the mineral instability of OPC, and it causes a fast-hardening reaction to OPC that appears by Cl, and alkali C ₃ A caused by stimulation of OPC. It is considered that the hydration reaction also affected BFs and FAs.

In addition, while NaOH and KOH are judged to be excessive in the optimal amount of stimulant used for strength expression, KCl is judged to be a level of use that can express appropriate performance when OPC and minerals are mixed. it is judged that it should be

If [FIG. 4] and [FIG. 5] showed hydration activity by comparing the compressive strength of the specimen using the mineral admixture as a binder with the strength value compared to the OPC 100% specimen, [FIG. 6] shows that OPC and the mineral admixture were 50% The ratio of contribution to the strength when each stimulant is used compared to the mixed test specimen is set as a plain specimen that does not use a stimulant by age and curing condition.

As included in the description of [Fig. 5] above, in the specimens using NaOH and KOH as stimulants, the strength was significantly decreased at all ages. However, in the specimen using KCl, it can be seen that the strength is improved on the contrary.

In particular, in the case of the BFs50 specimen with an initial age of 3 days, the specimen without the stimulant was 18.2 MPa, and by using the stimulant, the strength was increased by more than 90% to 34.6 MPa. did. By using KCl, a beneficial effect can be confirmed on the contribution of strength development at all ages of both BFs and FA mixed use specimens.

In addition, it can be seen that the effect is very maximized at the initial age. As confirmed in the coagulation result, when KCl was added to the blast furnace slag mixture, the setting rate was faster than that of the OPC mixture.

The experimental results according to the mineral admixture type showed that the compressive strength of FA was lower than that of BFs. In the present invention, a comparative experiment was conducted using the same weight ratio as the mineral admixture under the same conditions, but the mixing ratio of BFs and FA compared to OPC for hydration activity measurement presented in 'F 2563, fine powder of blast furnace slag for concrete' and 'L 5405, fly ash', respectively is presented as 50% and 25%, respectively, and it is judged that there is an appropriate mixing ratio, and the effect cannot be ignored.

Therefore, through future research, we plan to conduct additional research to evaluate the impact of using cement-derived KCl as a stimulant by considering the appropriate mixing rate as a mineral admixture.

[Mineral composition]

[Fig. 7] shows the results of mineral analysis of specimens using 50% of BFs and OPC, and [Fig. 8] shows the results of mineral analysis of specimens using 50% of FA and OPC.

First, in water curing among BFs, when KCl was used, hydrocalumite mineral that did not appear in other stimulant-added specimens appeared, which is known as one of Friedel's salts. It is reported that the presence of Friedel's salt may have an effect on reducing strength when using OPC alone, but reducing strength when using with mineral admixtures.

Also, research has been reported that the formation of Friedel's salt in a mixture of a large amount of BFs and OPC contributes to the increase in strength by filling the pores. In the case of autoclave curing, hydrocalumite, which appeared in underwater curing, does not appear.

The decrease in strength due to autoclave curing in BFs is considered to be related to the decomposition of hydrocalumite minerals and amorphous minerals.

Hydroclaumite was generated as KCl was added even in FA formulation, and Hydrocalumite did not appear as autoclave curing proceeded. In addition, it was confirmed that tobermorite mineral and katoite with high volume stability and tobermorite mineral which contributed to strength development at a lower density than C-S-H produced at room temperature in addition to decomposition of hydrocalumite as the autoclave curing proceeded. In the fly ash formulation, the generated minerals were more effective in filling the pores in the cement paste than the decomposition of minerals such as hydrocalumite, which is believed to have led to an increase in compressive strength.

As described above, in the present invention, as a basic invention to confirm the possibility of cement-derived KCl as an irritant for unrooted mortar and concrete, reagent-grade alkali stimulants of KOH and NaOH are used as a comparison object, and a mineral admixture as a binder. The following conclusions were obtained as a result of analyzing the basic characteristics of the mortar using either alone or in combination with OPC.

1. Although the coagulation of the paste due to the addition of KCl appears somewhat later than that of a strong alkali stimulant, it is possible to set within 24 hours even when using a mineral admixture alone, and when cement and mineral admixture are mixed, coagulation is promoted.

2. With the addition of KCl and alkali irritants, the fluidity was maintained or decreased slightly due to the increase in mortar viscosity.

3. When measuring compressive strength using KCl as an irritant, 100% mineral admixture showed lower strength than when NaOH and KOH stimulants were added. It was accelerated and showed an increase in strength of more than 20% at the age of 28 days.

4. It was confirmed that hydrocalumite, one of Friedel's salts, was generated when the KCl-added specimen was cured in water, and hydrocalumite was decomposed during curing in an autoclave at 180℃.

5. It was found that the addition of KCl promotes coagulation, promotes the initial hydration activity in the cement-mineral admixture mixture, and increases the strength by more than 20% compared to the conventional mixture as of 28 days. It is judged that KCl is more likely to be used when mixed with cement than when used alone with mineral mixtures. It is judged that it is necessary to review the optimal use conditions as stimulants for unrooted concrete products through analysis.

[Manufacturing of inorganic artificial marble]

[FIG. 9] is an artificial marble manufacturing process using a non-root concrete composition in which 50% of OPC and 50% of blast furnace slag powder are mixed by adding 10% of a binder to KCl derived from cement as a stimulant. Pressurized for 5 to 10 minutes with 100 MPa pressing force, reducing the water binder ratio to less than 20%, and after demolding, the handling strength is 5 MPa or more, and it is cured at 180 ° C. As an image of one inorganic artificial marble, it was confirmed that the compressive strength of 100 MPa or more was expressed.

The above description is merely illustrative of the technical idea of the present invention, and a person skilled in the art to which the present invention pertains will be able to make various modifications and variations without departing from the essential characteristics of the present invention. Therefore, the embodiments and drawings disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments and drawings. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

Claims (9)

Potassium chloride extracted from chlorine bypass dust generated in the cement manufacturing process is used as an alkali stimulant in a mixture of cement and fine powder of blast furnace slag or fly ash, or as an alkali stimulant in fine powder of blast furnace slag or fly ash Potassium chloride-free concrete stimulant extracted from chlorine bypass dust generated in the cement manufacturing process, characterized in that it promotes the initial hydration activity and setting of concrete
The method of claim 1,
Potassium chloride extracted from the chlorine bypass dust is mixed with cement and fine powder of blast furnace slag or a mixture of fly ash at 10% by weight, or mixed with fine powder of blast furnace slag or fine fly ash at 10% by weight. Generated in a cement manufacturing process Potassium chloride-free concrete stimulant extracted from chlorine bypass dust
The method of claim 1,
Potassium chloride extracted from the chlorine bypass dust has a purity of 95% and is a KCl solution mixed with water at a concentration of 150-200 g/L.
The method of claim 1,
Potassium chloride extracted from the chlorine bypass dust is a KCl solution obtained by mixing Chlorine Bypass Dust with water at a concentration of 400 g / ℓ, stirring with a magnetic stirrer, and filtering residual solids with a GF / C filter. Potassium chloride-free concrete stimulant extracted from chlorine bypass dust generated in the cement manufacturing process
The potassium chloride extracted from the chlorine bypass dust generated in the cement manufacturing process according to any one of claims 1 to 4 is mixed and used as an alkali stimulant in a mixture of cement and blast furnace slag fine powder or fly ash, or blast furnace slag fine powder or fly ash. Rooted concrete composition used as an alkali irritant in fine ash powder
6. The method of claim 5,
The unrooted concrete composition exhibits setting properties within 24 hours when used in fine blast furnace slag powder or fly ash without self-reactivity, and when used in fine blast furnace slag powder or fly ash, shows a compressive strength of 20 MPa or more at 28 days of age, cement When used as a mixture of blast furnace slag powder or fly ash, it exhibits setting characteristics within 4 hours, and the compressive strength at 28 days of age is 55 to 60 MPa.
6. The method of claim 5,
When the unrooted concrete composition is cured in water, hydrocalumite, one of Friedel's salts, is produced, and when cured in an autoclave condition at a temperature of 180°C, hydrocalumite is decomposed.
In the dehydration and pressurization process of the artificial marble manufacturing process, the unrooted concrete composition according to claim 5 was pressed with a pressing force of 100 MPa for 5 to 10 minutes to dehydrate the water binder ratio to within 20%, and the handling strength during demolding was 5 MPa or more, Inorganic artificial marble manufacturing method, characterized in that it expresses high strength of 100 MPa or more by curing for 8 hours or more by high-temperature and high-pressure curing at 180° C. and 10 atmospheres
Inorganic artificial marble, characterized in that it is manufactured according to the method for manufacturing inorganic artificial marble according to claim 8

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