KR102210942B1 - Process for the preparation of initialcompression improving agent for cement and cement composition - Google Patents

Abstract

The present invention relates to an initial strength improver and a cement composition for a blast furnace slag hydraulic cement combined with bottom ash and fly ash, and a method for producing slag cement.
By combining bottom ash and blast furnace slag, the crushing rate of the pulverized material is improved, and fly ash is combined with the remaining pulverized product to convert the iron component from the pulverized product to prepare an initial strength initiator, and a slag cement composition containing this improving agent. It consists of manufacturing.
The present invention shows the effect of stably expressing the compressive strength of 3 days and 7 days of age, which is the initial strength of cement, by replacing anhydrous gypsum, which is an initial strength improver that depends on imports. Also, the cost of cement manufacturing by using industrial waste At the same time as saving, it has the advantage of obtaining iron (Fe) component in the manufacturing process and using it as a raw material for steelmaking.

Description

Manufacturing method and cement composition for initial strength improving agent of cement using bottom ash and fly ash {Process for the preparation of initialcompression improving agent for cement and cement composition}

The present invention relates to a method and a cement composition for producing an initial strength improver for cement using bottom ash and fly ash, and specifically, by replacing gypsum, which is the main raw material for improving the initial strength of slag cement, using bottom ash and fly ash. It relates to a method for producing an agent for improving initial strength of a blast furnace slag cement stably expressing strength and a slag cement composition.

In the manufacture of general concrete, fly ash and blast furnace slag fine powder are widely used for reasons such as economic problems and suppression of hydration heat. Especially, fly ash has been mostly used as a cement clinker raw material and cement mixture since the mid 90s. Although it is increasing, batam ash generated along with fly ash generated in a circulating fluidized bed boiler is in a state of extremely low recycling rate due to a limited use field, and the bottom ash is currently mostly disposed of in landfill. It is causing serious environmental pollution.

The use of fly ash and slag at the time of manufacturing the cement mentioned above can provide economic benefits and effects such as reduction of hydration heat, but the initial strength is low, so the initial strength is low due to the addition of Ⅱ-insoluble anhydride. However, since Ⅱ-insoluble anhydrite depends entirely on imports, it affects the cost of cement manufacturing, and some are using Ⅱ-insoluble anhydride gypsum as an industrial by-product.

The above-described bottom ash does not contain a large amount of glass paste like fly ash or blast furnace slag, but it is judged that it contains a glass phase that can affect long-term strength to some extent, Fe ₂ O ₃ ( Hematite minerals), free-CaO, SO ₃ etc. are contained excessively. Using SO ₃ as an Ettringite stimulator and Pozzolan reaction activator in manufacturing blast furnace slag cement and hydraulic cement, the main raw material for improving the initial strength of cement. Although it can be predicted, studies on the improvement of the initial strength of cement using fly ash and bottom ash as a substitute for gypsum are poor.

Prior art related to fly ash and bottom ash or prior art related to initial strength improvement of cement.For example, in Patent Document 1, cement 18.0 wt% or more and 22.5 wt% or less, admixture 2.0 wt% or more and 2.5 wt% or less, sand 40 wt% or less , A concrete product characterized in that the mixture is formed by mixing a composition of 37.5 wt% or more and 80.0 wt% or less of the bottom ash in a ratio of 50 wt% or more and 70 wt% or less of the composition, and Patent Document 2 discloses (a) 10 to 30% by weight of an ash mixture comprising 25 to 50% by weight of bottom ash and 50 to 75% by weight of fly ash; (b) 30-50% by weight of fine blast furnace slag powder; And (c) 30-40% by weight of Portland cement, wherein the ash mixture is pulverized with a vibration mill for 30 to 120 minutes under the condition of applying physical energy of 50 to 150 KJ/s per unit volume of the ash mixture (m ³ ). Disclosed is a binder composition for concrete characterized by.

In addition, Patent Document 3 is composed of bottom ash, alkaline inorganic material and silicate, and the bottom ash and the remaining alkaline inorganic material and silicate are characterized in that the weight ratio is 70:30 to 80:20, and the alkaline inorganic material and the silicate Silver is characterized in that the weight ratio is 75:25 to 25:75, and the bottom ash is characterized by physically destroying and activating the glassy film using a pulverizing device, and the powder is 3,000 to 4,500 ㎠/g Wherein, the alkaline inorganic material is a mixture of calcium carbide (CaC2) and sodium hydroxide (NaOH) in the range of 6 to 16M, and the alkaline inorganic material exceeds 0 and 100 parts by weight compared to 100 parts by weight of sodium hydroxide. It is characterized in that the following, and the silicate discloses a non-fired binder including bottom ash, characterized in that the molar ratio of SiO2 and Na2O is sodium silicate of 1.0 to 3.4, but the prior art uses fly ash and bottom ash with cement and It is mixed and used, but there is no mention of improvement in initial strength or initial strength by replacing gypsum.

The inventor of the present invention confirmed that the initial strength expression of cement was improved by treating bottom ash with blast furnace slag and mixing fly ash sequentially to replace gypsum during cement production, and completed the present invention.

KR 10-0364911 B KR 10-1312562 B KR 10-1339332 B

The problem to be solved in the present invention is to develop as a gypsum substitute material, which is the main raw material for improving the initial strength of cement, by a combination treatment of blast furnace slag and bottom ash and sequential combination of fly ash, and Fe ₂ O ₃ relates to a mineral based on the method for producing the agent for improving early strength of cement to recycle the iron was separated using a group classification of the grinder as a steel making material and a cement composition provided.

More specifically, by using fly ash and bottom ash collected in a circulating fluidized bed boiler, the side effects that adversely affect the durability of hydraulic cement by components such as free CaO and reactive CaO are solved, and the initial strength is 3 days. It is intended to provide a method for producing a blast furnace slag cement improving agent capable of stably expressing compressive strength for 7 days of age and a blast furnace slag cement composition.

A method of manufacturing an initial strength improving agent for cement using bottom ash and fly ash as a solution to the problem for achieving the object according to the present invention is a). The first step of combining the original bottom ash or the hydrated bottom ash and the original blast furnace water slag and finely pulverized to obtain a first pulverized product, b). The second step of separating the iron component (Fe) and the pulverized product by classifying the first pulverized product of the first step, and c) the second pulverized product obtained in the second step It consists of a third step of compounding fly ash to obtain an improving agent.

In one embodiment of the method for manufacturing an initial strength improving agent for slag cement using bottom ash and fly ash according to the present invention, a). A first step of combining 100 parts by weight of bottom ash in its original state or bottom ash in a hydrated state dried by hydration and 5 to 10 parts by weight of blast furnace water slag in its original state and pulverizing to obtain a first pulverized product, b). The second step of separating the iron component (Fe) and the pulverized product by classifying the first pulverized product of the first step, and c) the second pulverized product 100 obtained in the second step It consists of a third step of compounding 30 to 35 parts by weight of fly ash based on parts by weight to obtain an improving agent.

A method for producing a slag cement composition using bottom ash and fly ash as a solution to the problem for achieving another object of the present invention is a). The first step of obtaining a first pulverized product by combining the original bottom ash or hydrated and dried hydrated bottom ash and 5 to 10 parts by weight of blast furnace water slag in the original state and pulverizing it. b). The second step of separating the iron component (Fe) and the pulverized product by classifying the first pulverized product of the first step to obtain the iron component (Fe) and the second pulverized product, c). A third step of obtaining an improving agent by mixing 30 to 35% by weight of fly ash to the second pulverized material obtained in the second step, and d) 2 to 15% by weight of the improving agent of the third step based on the total weight of cement It consists of the fourth step of obtaining.

The original bottom ash (Bottom Ash-Original) selected in the present invention means the bottom ash as it is generated in the circulating fluidized bed boiler. It is a hydrated bottom ash that has been hydrated with water and then dried at 100°C.

The original blast furnace water slag of the present invention is vitrified into a sand state by rapid cooling by spraying high-pressure water onto molten slag generated in a blast furnace (blast furnace) of an iron making process, and is not pulverized.

The fly ash (Fly Ash) is fly ash generated in a circulating fluidized bed boiler, and the cement of the present invention is a blast furnace water material composed of 50 to 90 parts by weight of fine powder blast furnace water slag based on 100 parts by weight of Portland cement, mixed cement or Portland cement. It is made of slag cement.

The initial strength improver of hydraulic cement that combines bottom ash and fly ash according to the present invention replaces anhydrous gypsum, an initial strength improver that depends on imports, and stably expresses the initial strength of cement, which is 3 days old and 7 days old, compressive strength. Has the effect of

In addition, the use of industrial waste has the advantage of reducing the cost of cement manufacturing and obtaining iron (Fe) components during the manufacturing process and using them as a raw material for steelmaking.

Hereinafter, it will be described in detail with reference to specific details, examples and test examples for carrying out the present invention, but the present invention is not limited by the examples described below.

The method of manufacturing the initial strength improver of slag cement using bottom ash and fly ash according to the present invention is a). A first step of combining 100 parts by weight of bottom ash in its original state or bottom ash in a hydrated state dried by hydration and 5 to 10 parts by weight of blast furnace water slag in its original state and pulverizing to obtain a first pulverized product, b). The second step of separating the iron component (Fe) and the pulverized product by classifying the first pulverized product of the first step, and c) the second pulverized product obtained in the second step It consists of a third step of compounding 30 to 35 parts by weight of fly ash based on 100 parts by weight to obtain an improving agent.

The original bottom ash used for selection in the present invention is a Circulating Fluidized Bed Combustor Bottom Ash-Original (Circulating Fluidized Bed Combustor Bottom Ash-Original) generated in a circulating fluidized bed boiler, and the bottom ash in a hydrated state dried by hydration is the bottom ash in its original state. It is Circulating Fluidized Bed Combustor Bottom Ash-Hydration that was hydrated with water and then dried at 100°C.

Bottom ash according to the present invention is preferably hydrated and dried bottom ash in a hydrated state. For example, the bottom ash in its original state generated in the circulating fluidized bed boiler is a chemical composition of bottom ash produced by SS in Korea below [Table 1] Shown in.

ingredient SiO ₂ Al ₂ O ₃ Fe ₂ O ₃ CaO MgO SO ₃ LOI Furtherance(%) 12.57 5.96 9.62 35.49 6.10 28.11 1.04

The blast furnace slag in its original state (A) is made by spraying high-pressure water onto the molten slag generated in the blast furnace (blast furnace) of the iron making process to vitrify it into sand by rapid cooling, and is not pulverized. , For example, blast furnace water slag, which is a raw material produced at POSCO's Gwangyang Works in Korea, and dried to less than 1% moisture using a dryer. The chemical composition is shown in [Table 2] below.

ingredient SiO ₂ Al ₂ O ₃ Fe ₂ O ₃ CaO MgO SO ₃ LOI Furtherance(%) 35.21 15.32 0.51 43.30 3.77 0.44 0.15

The first step according to the present invention is a process of pulverizing by combining the bottom ash in the original state or the bottom ash in the hydration state and the blast furnace water slag in the original state, and the bottom ash in the original state of the fine sand particle size or the bottom ash in the hydration state is somewhat By combining and pulverizing the blast furnace water slag in its original state with tough properties (toughness), it is possible to obtain a first pulverized product with more improved powderiness compared to pulverizing each alone under the same pulverization conditions. It shows an improved effect on the separation of iron components by

The second step of the present invention is a process of separating the iron component by classifying the first pulverized product obtained in the first step and obtaining a second pulverized product, and as described above, the bottom ash of the original state of the sand particle size or the hydration state By combining and pulverizing the bottom ash of the blast furnace and slag in the original state with a somewhat toughness (toughness), compared to pulverizing each alone under the same pulverizing conditions, by obtaining a first pulverized product of more improved powderiness. Iron components can be separated and recovered in high yield.

Classification of the first pulverized material in the second step is performed by using a conventional classifier known in the art, and a detailed description thereof will be omitted since it can be easily adopted by those skilled in the art. In addition, it is possible to obtain an iron component and a second pulverized product by performing the first and second steps according to the present invention using a conventional mill-equipment classifier.

The third step of the present invention is a process of mixing fly ash into the second pulverized product obtained by separating the iron component from the first pulverized product of the first step to obtain an improving agent, and the fly ash is generated in a circulating fluidized bed boiler. It is a fly ash, for example, a product produced by SS in Korea, and its chemical composition and powderiness are shown in [Table 3] below.

ingredient SiO ₂ Al ₂ O ₃ Fe ₂ O ₃ CaO MgO SO ₃ LOI Fineness (cm ² /g) Furtherance(%) 25.61 12.69 14.46 27.18 8.01 9.18 1.20 6260

And the method for producing a cement composition using bottom ash and fly ash according to the present invention a). A first step of combining 100 parts by weight of bottom ash in its original state or bottom ash in a hydrated state dried by hydration and 5 to 10 parts by weight of blast furnace water slag in its original state and pulverizing to obtain a first pulverized product, b). The second step and c) of separating the iron component (Fe) and the second pulverized product by classifying the first pulverized product of the first step to obtain the iron component (Fe) and the second pulverized product, and c). The third step of obtaining an improving agent by blending 30 to 35 parts by weight of fly ash with respect to 100 parts by weight of the second pulverized material obtained in the second step and d). It consists of a fourth step of obtaining a cement composition by adding 2 to 15% by weight of the improving agent of the third step based on the total weight of the cement.

In the method of manufacturing a cement composition using bottom ash and fly ash of the present invention, steps 1 to 3 are the same as the method of manufacturing the improver of the present invention, and the cement of the fourth step is Portland cement, mixed cement or Portland 100 A blast furnace water slag cement composed of 50 to 90 parts by weight of fine powder blast furnace water slag is selected based on parts by weight.

The cement of the fourth step of the present invention is preferably a blast furnace water slag cement composed of 50 to 90 parts by weight of fine powder blast furnace water slag per 100 parts by weight of Portland.For example, the blast furnace water slag of the fourth step is a product of domestic D company. The chemical composition and powderiness are shown in Table 4 below.

ingredient SiO ₂ Al ₂ O ₃ Fe ₂ O ₃ CaO MgO SO ₃ LOI Fineness (cm ² /g) Furtherance(%) 35.29 15.40 0.41 43.65 3.65 0.47 0.12 4400

Hereinafter, the present invention will be described in more detail through <Examples> and <Test Examples>.

<Example 1>

-Manufacture of the first pulverized product combining bottom ash and blast furnace slag; Step 1

950 g of bottom ash in the original state of fine sand particle size produced by the domestic SS company and 50 g of blast furnace water slag in the original state dried to less than 1% moisture using a dryer using a raw material produced at the POSCO Gwangyang Works ) Was rotated 5,000 times to obtain a first pulverized product.

-Separation and recovery of iron components and manufacture of improving agents; Step 2 and Step 3

The first pulverized product obtained above was separated from the iron component by a classifier, and 34 parts by weight of fly ash produced by the domestic SS company were mixed with respect to 100 parts by weight of the remaining second pulverized product to prepare an improving agent.

<Example 2>

An improving agent was prepared in the same manner as in <Example 1>, except that hydration and dry bottom ash in a hydrated state was used.

<Comparative Example 1>

For comparison with the first-stage pulverization of <Example 1> and <Example 2>, the blast furnace slag was pulverized in the same pulverizing conditions as in the <Example 1> to obtain a pulverized product.

<Test Example 1>

Chemical composition and KS L 5106 for the samples of the first pulverized material of each of the <Example 1> and <Example 2> and the pulverized material of <Comparative Example 1> and KS L 5106 (Test method of powder of Portland cement by air permeation device) The powderiness measured by is shown in [Table 5] below.

division Composition (%) LOI(%) Powder degree (cm ² /g) SiO ₂ Al ₂ O ₃ Fe ₂ O ₃ CaO MgO SO ₃ Example 1 13.74 6.47 9.02 35.92 6.17 26.50 1.07 7460 Example 2 13.26 6.25 8.67 34.56 5.93 25.44 4.76 7050 Comparative Example 1 35.21 15.32 0.51 43.30 3.77 0.44 0.15 3800

As shown in [Table 5], it can be seen that the pulverized product pulverized by combining bottom ash and slag showed higher powderiness compared to <Comparative Example 1> in which the slag was crushed alone, and accordingly, the iron component was separated by classification. It can be expected that the recovery rate will also improve.

<Test Example 2>

For a comparative test of the pulverization yield and generation of crushed iron for combination pulverization and single pulverization, 1000 g of each compound blended in the composition ratio shown in [Table 6] below is pulverized by rotating 5,000 times using a crushing daily index tester (ball mill). 30g of water was collected as a sample, and the pulverization yield (%) and powder iron generation ratio (%) were measured using a KS L 5112 45㎛ (325mesh) powder measuring body, and the results are shown in [Table 6] below.

division Residual amount (g) Crushing yield (%) Powder generation ratio (%) Bottom Ash(%) Blast furnace slag (%) - 100 4.31 85.6 0.23 100 - 8.51 71.6 12.7 Original state 95 5 9.14 74.25 12.11 Hydration 95 5 7.54 74.87 11.85

As shown in [Table 6], blast furnace water slag alone pulverization has a slight level of powder iron generation, and bottom ash containing a lot of Fe is combined with blast furnace water slag rather than single pulverization. You can see that it improves.

<Example 3> and <Example 4>

-Manufacturing of water slag cement composition

Portland cement 49 parts by weight, the blast furnace water slag is prepared by uniformly mixing 43 parts by weight of fine powder blast furnace slag of domestic D company and 8 parts by weight of each of the improvers prepared in <Example 1> and <Example 2> to prepare a water slag cement composition I did.

<Comparative Example 2>

For comparison, a water-based slag cement composition was prepared in which 49 parts by weight of Portland cement, 49 parts by weight of fine powder blast furnace slag (B) of D company, and 2 parts by weight of natural anhydrite as shown in Table 7 below were mixed.

ingredient SiO ₂ Al ₂ O ₃ Fe ₂ O ₃ CaO MgO SO ₃ LOI Powder degree (cm ² /g) Furtherance(%) 1.84 Tr Tr 39.82 Tr 55.70 1.10 3900

<Test Example 3>

The slag cement prepared in <Example 1>, <Example 2> and <Comparative Example 2> was used as a sample to measure the chemical composition and powderiness, and the results are shown in Table 8 below.

ingredient Chemical composition (%) LOI(%) Fineness (cm ² /g) SiO ₂ Al ₂ O ₃ Fe ₂ O ₃ CaO MgO SO ₃ Example 3 26.38 9.74 2.53 52.00 3.85 3.17 1.14 4300 Example 4 26.35 9.73 2.51 51.92 3.83 3.11 1.37 4310 Comparative Example 2 27.22 10.03 1.72 52.71 3.57 2.53 1.10 4000

As shown in [Table 8], as a result of the chemical analysis of the blast furnace slag cement composition of the present invention, the SO ₃ content was 3.17% and 3.11%, and SO ₃ of <Comparative Example 2> was mixed with natural anhydrite blended to improve initial strength. was found to be higher than the content of 2.53%, powder can also be seen that a high <Comparative example ^2> 4000cm 2 / g compared to 4300 ~ 4310cm ² / g of.

<Test Example 4>

For the cement compressive strength test, the W/C ratio of the slag cement compositions of <Example 3>, <Example 4> and <Comparative Example 2> was 50 according to KS L 5105 (compression strength test method of hydraulic cement mortar). After preparing each test sample by fixing it at %, store each test sample in a constant temperature/humidifier (temperature 20℃, humidity 95%) for 24 hours and then cure in a curing tank (20℃ condition), 3 days, 7 days, 28 The compressive strength was measured for each age, and the results are shown in Table 9 below.

division Compressive strength (N/mm ² ) 3 days 7 days 28 days burglar % burglar % burglar % Example 3 18.75 103.71 30.91 99.23 56.31 90.30 4 in implementation 18.98 104.98 30.96 99.39 56.49 90.59 Comparative Example 2 18.08 100 31.15 100 62.36 100

As shown in [Table 9], the initial strength of <Example 3> and <Example 4> showed strength development that exceeded the initial strength of natural gypsum blended cement at 3 days of age, which was reacted with blast furnace water slag It is judged that the initial compressive strength expression increases as the hydration generation of Ettringite by sulfate proceeds more actively than the Pozzolan reaction during the time of the present invention, and the initial strength invention rate is 99.23% and 99.39% even at 7 days of age. It can be seen that the improving agent can replace natural gypsum in the expression of the initial strength of cement.

Claims (9)

a). A first step of combining 100 parts by weight of hydrated bottom ash and 5 to 10 parts by weight of blast furnace water slag in the original state and pulverizing to obtain a first pulverized product,
b). The second step of separating the iron component (Fe) and the pulverized product by classifying the first pulverized product of the first step to obtain the iron component (Fe) and the second pulverized material used as steelmaking raw materials, and
c) Initial strength improver of cement using bottom ash and fly ash, comprising a third step of mixing 30 to 35 parts by weight of fly ash with respect to 100 parts by weight of the second pulverized material obtained in the second step. Method of manufacturing. delete The method according to claim 1, wherein the original blast furnace water slag in the first step is vitrified into a sand state by spraying high-pressure water onto the molten slag generated in the blast furnace of the iron making process and quenched, and is a blast furnace water slag in an uncrushed state. Method for producing a cement initial strength improving agent using bottom ash and fly ash, characterized in that. delete a). A first step of combining 100 parts by weight of hydrated bottom ash and 5 to 10 parts by weight of blast furnace water slag in the original state and pulverizing to obtain a first pulverized product,
b). The second step of separating the iron component (Fe) and the pulverized product by classifying the first pulverized product of the first step to obtain the iron component (Fe) and the second pulverized material used as steelmaking raw materials,
c). The third step of obtaining an improving agent by blending 30 to 35 parts by weight of fly ash based on 100 parts by weight of the second pulverized material obtained in the second step
d). Method for producing a cement composition using bottom ash and fly ash, characterized in that it comprises a fourth step of obtaining a cement composition by adding 2 to 15% by weight of the improving agent of the third step based on the total weight of the cement. delete The blast furnace according to claim 5, wherein the original blast furnace water slag (A) in the first step is vitrified into sand by rapid cooling by spraying high-pressure water onto the molten slag generated in the blast furnace of the iron making process. Method for producing a cement composition using bottom ash and fly ash, characterized in that water slag. delete The bottom ash and fly ash according to claim 7, wherein the cement in the fourth step is a blast furnace water-based slag cement composed of 50 to 90 parts by weight of finely powdered blast furnace water-based slag based on 100 parts by weight of Portland cement, mixed cement or Portland cement. Method for producing a cement composition using.