阅读说明：本技术 矿渣碳化改性方法、碳化改性矿渣胶凝材料及其制备方法 (Slag carbonization modification method, carbonization modified slag cementing material and preparation method thereof ) 是由 贺艳 相继春 梁航 刘乐平 崔学民 于 2021-08-20 设计创作，主要内容包括：本发明提供了一种矿渣碳化改性方法、碳化矿渣胶凝材料及其制备方法,该矿渣碳化改性方法,包括以下步骤：将矿渣置于温度为20～30℃、相对湿度为50～70％、二氧化碳体积浓度为30-100％的条件下反应3～168h,即完成对矿渣的改性。本发明的矿渣碳化改性方法,通过有效的气-固反应碳化改性矿渣的方法,矿渣碳化改性不仅可以捕获和储存部分CO-(2),碳化改性的矿渣又可以在不影响碳化改性矿渣胶凝材料其他性能的前提下,有效延长碳化矿渣胶凝材料的凝结时间；以碳化改性的矿渣为原料,可以将制备的矿渣胶凝材料的初凝时间控制在合理的范围内,而且用碳化矿渣制备的矿渣胶凝材料不影响其后期抗压强度的发展和反应产物。(The invention provides a slag carbonization modification method, a carbonized slag cementing material and a preparation method thereof, wherein the slag carbonization modification method comprises the following steps: and (3) placing the slag at the temperature of 20-30 ℃, the relative humidity of 50-70% and the volume concentration of carbon dioxide of 30-100% for reaction for 3-168 h, thus finishing the modification of the slag. The slag carbonization modification method of the invention can not only capture and store partial CO by the effective gas-solid reaction carbonization modification method of the slag 2 The carbonized modified slag can effectively prolong the setting time of the carbonized slag cementing material on the premise of not influencing other properties of the carbonized modified slag cementing material; the initial setting time of the prepared slag cementing material can be controlled within a reasonable range by taking carbonized modified slag as a raw material, and the development and the later compressive strength of the slag cementing material prepared from the carbonized slag are not influencedAnd (3) reaction products.)

1. The slag carbonization modification method is characterized by comprising the following steps: and (3) placing the slag at the temperature of 20-30 ℃, the relative humidity of 50-70% and the volume concentration of carbon dioxide of 30-100% for reaction for 3-168 h, thus finishing the modification of the slag.

2. A carbonized modified slag cement comprising the slag obtained by the modification method according to claim 1.

3. The carbonized modified slag cement of claim 2, further comprising a sodium hydroxide solution or a water glass solution.

4. The carbonized modified slag cement of claim 3, wherein the pH of the sodium hydroxide solution is 13 to 15.

5. The carbonized modified slag cement of claim 3, wherein the water glass solution comprises NaOH, industrial water glass and water, and the pH of the water glass solution is 12 to 14.

6. The carbonized modified slag cement according to claim 3, wherein the modulus of the water glass solution is 1 to 2.

7. A method for preparing the carbonized modified slag cement as described in any one of claims 1 to 6, comprising the steps of:

and mixing the slag and optional sodium hydroxide solution or water glass solution, pouring the mixture into a mold, and curing to obtain the alkali-activated carbonized modified slag cementing material.

8. The method according to claim 7, wherein the slag, optionally sodium hydroxide solution or water glass solution, and water are mixed and poured into a mold, and cured to obtain the alkali-activated carbonized modified slag cement, specifically: mixing the slag, optional sodium hydroxide solution or water glass solution and water, pouring the mixture into a mold, curing the mixture for 24 hours at the temperature of 19-21 ℃ and the relative humidity of 90-100%, demolding, and continuing curing the mixture for 20-30 days.

Technical Field

The invention relates to the technical field of slag materials, in particular to a slag carbonization modification method, a carbonization modification slag cementing material and a preparation method thereof.

Background

The slag is a byproduct in the process of smelting iron, reacts with proper alkali (such as water glass and sodium hydroxide) to form a cementing material, and is a good cement substitute. Alkali-activated slag not only utilizes solid waste to reduce carbon dioxide emissions, but also has many superior properties compared to Ordinary Portland Cement (OPC). However, the short setting time of alkali-activated slag, particularly the setting time of water glass-activated slag of less than 30min, hinders practical use thereof. The ideal method is to develop a chemical retarder with excellent performance so as to delay the solidification of alkali-activated slag without affecting other properties. However, since alkali excites OH in slag^-Too high a concentration results in a retarder suitable for use with cement that does not work effectively in alkali-activated slag systems. Currently, the effective retarders in alkali-activated slag systems are mainly phosphoric acid/phosphate and borax. Although a good retardation effect is obtained, the use of a large amount of the retarder is considered to be impractical in combination with the decrease in the properties of the alkali-activated slag, such as strength decrease, increase in drying shrinkage, and the like.

There is a need for improvement based on the current short slag setting time, which hinders practical use thereof.

Disclosure of Invention

In view of the above, the invention provides a slag carbonization modification method, an alkali-activated carbonization modification slag cementing material with controllable condensation time and a preparation method thereof, so as to solve or partially solve the technical problems in the prior art.

In a first aspect, the invention provides a slag carbonization modification method, which comprises the following steps: and (3) placing the slag at the temperature of 20-30 ℃, the relative humidity of 50-70% and the volume concentration of carbon dioxide of 30-100% for reaction for 3-168 h, thus finishing the modification of the slag.

In a second aspect, the invention also provides a carbonized modified slag cement comprising slag obtained by the modification method.

In a third aspect, the invention also provides a preparation method of the carbonized modified slag cementing material, which comprises the following steps:

and mixing the slag, optional sodium hydroxide solution or water glass solution and water, pouring the mixture into a mold, and curing to obtain the alkali-activated carbonized modified slag cementing material.

Compared with the prior art, the slag carbonization modification method, the carbonization modification slag cementing material and the preparation method thereof have the following beneficial effects:

(1) the slag carbonization modification method of the invention can not only capture and store partial CO by the effective gas-solid reaction carbonization modification method of the slag₂The carbonization modified slag can effectively prolong the setting time of the alkali-activated carbonization modified slag cementing material on the premise of not influencing other properties of the alkali-activated slag cementing material; the prepared alkali-activated carbonized modified slag can be controlled within a reasonable initial setting time range by the carbonized modified slag, and the compressive strength and reaction products of the alkali-activated slag cementing material are not influenced by the carbonized modified slag;

(2) the preparation method of the carbonized modified slag cementing material can control the condensation time by adjusting the exposure time of the slag in carbon dioxide; NaOH solution, water glass solution with modulus of 1.0 and water glass solution with modulus of 2.0 are excited in CO₂The initial setting time of the slag after 168 hours of the exposure is respectively prolonged to 134min, 54min and 1167 min.

(3) Compared with the freshly ground slag (non-carbonized modified slag), the hydration reaction curve of the carbonized modified slag cementing material prepared by the invention has an obvious low reaction rate stage before the induction period. During this time, the dissolution rate of the aluminosilicate structure in the slag carbonized layer is low, and once the carbonized layer is broken, the carbonized slag undergoes the same hydration reaction process as that of the freshly ground slag.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

FIG. 1 is a morphology of granulated blast furnace slag used in example 1 of the present invention and a surface topography of the slag after ball milling;

FIG. 2 is a graph showing the setting time of the carbonized modified slag cements prepared in examples 7 to 24 and comparative examples 2 to 4 of the present invention;

FIG. 3 is a graph showing the compressive strength of the carbonized modified slag cements prepared in examples 25 to 42 of the present invention and comparative examples 5 to 7;

FIG. 4 is an XRD (X-ray diffraction) spectrum of the carbonized modified slag cementing material prepared in examples 7-24 and comparative examples 2-4 of the invention;

FIG. 5 is an XRD spectrum of slag obtained by carbonization modification treatment in examples 1 to 6 of the present invention and comparative example 1;

FIG. 6 is FTIR spectra of slag subjected to carbonization modification treatment in examples 1 to 6 of the present invention and comparative example 1;

FIG. 7 is a thermogravimetric analysis chart of slag subjected to a carbonization modification treatment in examples 1 to 6 of the present invention and comparative example 1. Wherein the left graph is a thermogravimetric weight (TG) graph and the right graph is a derivative thermogravimetric weight loss (DTG) graph;

FIG. 8 is an XPS spectrum of slag subjected to a carbonization modification treatment in examples 1 to 6 of the present invention and comparative example 1;

FIG. 9 is a graph fitted with O1s spectra of slag subjected to carbonization modification treatment in examples 1 to 6 of the present invention and comparative example 1;

FIG. 10 is a graph of normalized cumulative exotherm for 5000 minutes of alkali-activated slag reaction with different activators. The left panel shows the change in the exotherm of the reaction for the first 5000 minutes and the right panel shows a close-up of the left panel over the first 1000 minutes.

Detailed Description

In the following, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

The embodiment of the application provides a slag carbonization modification method, which comprises the following steps:

and (3) placing the slag at the temperature of 20-30 ℃, the relative humidity of 50-70% and the volume concentration of carbon dioxide of 30-100% for reaction for 3-168 h, thus completing the carbonization modification of the slag.

The slag carbonization modification method further comprises the step of placing the slag in N before slag modification₂Protecting in atmosphere, mechanically ball-milling the slag, and screening the slag by using a 100-mesh screen to remove coarse particles. The application provides a simple and effective method for carbonizing and modifying slag through gas-solid reaction, and the slag carbonization modification can capture and store partial CO₂And the setting time of the alkali-activated carbonized slag cementing material can be delayed on the premise of not influencing other properties. The analysis result of the carbonized modified slag shows that: slag exposure to CO₂CO after 168h under atmosphere₂The absorption amount was 0.33mmol_CO2/g_slagThe formation of a low-reactivity film on the slag surface reduces its early reactivity; leading to an extended Initial setting time and a significant Pre-Initial reaction period (Pre-Initial period) preceding the Initial reaction period (Initial period) of the slag hydration reaction curve.

Based on the same inventive concept, the embodiment of the application also provides a carbonized modified slag cementing material which comprises slag obtained by modification by the modification method.

In some embodiments, the carbonized modified slag cement further comprises a sodium hydroxide solution or a water glass solution. In the examples of the present application, a sodium hydroxide solution or a water glass solution is used as the alkali activator.

In some embodiments, the pH of the sodium hydroxide solution is between 13 and 15.

In some embodiments, the water glass solution comprises NaOH, industrial water glass and water, and the pH value of the water glass solution is 12-14.

In some embodiments, the water glass solution has a modulus of 1.0 to 2.0. The modulus M is SiO in the water glass solution₂With Na₂Molar ratio of O.

Based on the same inventive concept, the embodiment of the application also provides a preparation method of the carbonized slag cementing material, which comprises the following steps:

and mixing the slag, optional sodium hydroxide solution or water glass solution and water, pouring the mixture into a mold, and curing to obtain the carbonized modified slag cementing material.

In some embodiments, slag, an optional sodium hydroxide solution or a water glass solution, and water are mixed and poured into a mold, and the mixture is cured to obtain the carbonized modified slag cement material, which specifically comprises: mixing the slag, optional sodium hydroxide solution or water glass solution and water, pouring the mixture into a mold, curing the mixture for 24 hours at the temperature of 19-21 ℃ and the relative humidity of 90-100%, demolding, and continuing curing the mixture for 20-30 days. Wherein the mass ratio of the slag, optional sodium hydroxide solution or water glass solution and water is (60-75): (10-25): (10-25).

The slag carbonization modification method, the carbonized slag cement and the preparation method thereof according to the present application will be further described with specific examples

Example 1

The embodiment of the application provides a slag carbonization modification method, which comprises the following steps:

s1, placing the slag in N₂Protecting in atmosphere, then carrying out mechanical ball milling on the slag, and then screening the slag by using a 100-mesh screen to remove coarse particles; among them, the slag used is Granulated Blast Furnace Slag (GBFS) provided by hong Yao new building materials Co., Ltd.

And S2, placing the ball-milled slag in the S1 at the temperature of 25 ℃, the relative humidity of 60% and the volume concentration of carbon dioxide of 90% for reaction for 3 hours, namely, finishing the modification of the slag, and recording the modified slag as S3.

Example 2

The slag carbonization modification method provided by the embodiment of the application is the same as that of the embodiment 1, except that the reaction time in S2 is 6h, and the slag obtained after modification is marked as S6.

Example 3

The slag carbonization modification method provided by the embodiment of the application is the same as that of the embodiment 1, except that the reaction time in S2 is 12h, and the slag obtained after modification is marked as S12.

Example 4

The slag carbonization modification method provided by the embodiment of the application is the same as that of the embodiment 1, except that the reaction time in S2 is 24h, and the slag obtained after modification is marked as S24.

Example 5

The slag carbonization modification method provided by the embodiment of the application is the same as that of the embodiment 1, except that the reaction time in S2 is 72h, and the slag obtained after modification is marked as S72.

Example 6

The slag carbonization modification method provided by the embodiment of the application is the same as that of the embodiment 1, except that the reaction time in S2 is 168h, and the slag obtained after modification is marked as S168.

Comparative example 1

The slag carbonization modification method provided by the comparative example only includes the step S1 in example 1, the reaction time is 0h in S2, and the slag obtained after modification is marked as S0 (i.e., freshly ground slag which is not carbonized and modified).

Example 7

The embodiment of the application provides a preparation method of a carbonized modified slag cementing material, which comprises the following steps:

s1, dissolving NaOH in water to prepare 8mol/L NaOH solution, standing for 24h for later use, and using the NaOH solution as an alkali activator;

s2, weighing NaOH solution and water in the S3 and S1 of the slag obtained in the embodiment 1 according to the mass ratio of 70.09:15.26:14.65 for later use;

s3, mixing NaOH solution in slag S3 and S1 with water, stirring the mixture in a JJ-5 type cement mortar stirrer at 140r/min for 1min, then stirring the mixture at 290r/min for 3min, pouring the mixture into a mold, curing the mixture in a cement concrete constant-temperature constant-humidity standard curing box at 20 ℃ and relative humidity of 100% for 24h, demolding, and continuing curing the mixture in the standard curing box for 28 days until testing.

Example 8

The preparation method of the carbonized modified slag cement provided in the example of this application is the same as that of example 7 except that the slag used in S2 is the slag S6 obtained in example 2.

Example 9

The preparation method of the carbonized modified slag cement provided in the examples of the present application is the same as example 7 except that the slag used in S2 is the slag S12 obtained in example 3.

Example 10

The preparation method of the carbonized modified slag cement provided in the examples of the present application is the same as example 7 except that the slag used in S2 is the slag S24 obtained in example 4.

Example 11

The preparation method of the carbonized ore modified slag cement provided by the embodiment of the present application is the same as that of embodiment 7, except that the slag used in S2 is the slag S72 obtained in embodiment 5.

Example 12

The process for producing a carbonized modified slag cement according to the example of the present application is the same as that of example 7 except that the slag used in S2 is the slag S168 obtained in example 6.

Comparative example 2

The example of the present application provides a method for preparing a carbonized modified slag cement, which is similar to example 7, except that the slag used in S2 is the slag S0 obtained in comparative example 1.

Example 13

The embodiment of the application provides a preparation method of a carbonized modified slag cementing material, which comprises the following steps:

s1, preparation of a water glass solution: adding NaOH and water into industrial water glass with the modulus of 3.14, stirring until the solid is completely dissolved to obtain a water glass solution (marked as 1M-Wg) with the modulus of 1.0, sealing and standing for 24 hours for later use, wherein the pH value of the water glass solution is 13.94;

s2, weighing the water glass solution and water in the slag S3 and S1 obtained in the embodiment 1 according to the mass ratio of 67.21:13.76:19.03 for later use;

s3, mixing the water glass solution in the slag S3 and S1 with water, stirring the mixture in a JJ-5 type cement mortar stirrer at 140r/min for 1min, then stirring the mixture at 290r/min for 3min, pouring the mixture into a mold, curing the mixture in a standard curing box for 24h at the temperature of 20 ℃ and the relative humidity of 100 percent, demolding, and continuing curing the mixture in the standard curing box for 28 days until the test.

Example 14

The preparation method of the carbonized modified slag cement provided in the example of this application is the same as that of example 7 except that the slag used in S2 is the slag S6 obtained in example 2.

Example 15

The preparation method of the carbonized modified slag cement provided in the examples of the present application is the same as example 7 except that the slag used in S2 is the slag S12 obtained in example 3.

Example 16

The preparation method of the carbonized modified slag cement provided in the examples of the present application is the same as example 7 except that the slag used in S2 is the slag S24 obtained in example 4.

Example 17

The preparation method of the carbonized modified slag cement provided in the examples of the present application is the same as example 7 except that the slag used in S2 is the slag S72 obtained in example 5.

Example 18

The process for producing a carbonized modified slag cement according to the example of the present application is the same as that of example 7 except that the slag used in S2 is the slag S168 obtained in example 6.

Comparative example 3

The example of the present application provides a method for preparing a carbonized modified slag cement, which is similar to example 7, except that the slag used in S2 is the slag S0 obtained in comparative example 1.

Example 19

The embodiment of the application provides a preparation method of a carbonized modified slag cementing material, which comprises the following steps:

s1, preparation of a water glass solution: adding NaOH and water into industrial water glass with the modulus of 3.14, and stirring until the solid is completely dissolved to obtain a water glass solution (marked as 2M-Wg) with the modulus of 2.0, wherein the pH value of the water glass solution is 12.86;

s2, weighing the water glass solution and water in the slag S3 and S1 obtained in the example 1 according to the mass ratio of 64.40:23.52:12.07 for later use;

s3, mixing the water glass solution in the slag S3 and S1 with water, stirring the mixture in a JJ-5 type cement mortar stirrer at 140r/min for 1min, then stirring the mixture at 290r/min for 3min, pouring the mixture into a mold, curing the mixture in a standard curing box for 24h at the temperature of 20 ℃ and the relative humidity of 100 percent, demolding, and continuing curing the mixture in the standard curing box for 28 days until the test.

Example 20

The preparation method of the carbonized modified slag cement provided in the example of this application is the same as that of example 7 except that the slag used in S2 is the slag S6 obtained in example 2.

Example 21

The preparation method of the carbonized modified slag cement provided in the examples of the present application is the same as example 7 except that the slag used in S2 is the slag S12 obtained in example 3.

Example 22

The preparation method of the carbonized modified slag cement provided in the examples of the present application is the same as example 7 except that the slag used in S2 is the slag S24 obtained in example 4.

Example 23

The preparation method of the carbonized modified slag cement provided in the examples of the present application is the same as example 7 except that the slag used in S2 is the slag S72 obtained in example 5.

Example 24

The process for producing a carbonized modified slag cement according to the example of the present application is the same as that of example 7 except that the slag used in S2 is the slag S168 obtained in example 6.

Comparative example 4

The example of the present application provides a method for preparing a carbonized modified slag cement, which is similar to example 7, except that the slag used in S2 is the slag S0 obtained in comparative example 1.

Example 25

The embodiment of the application provides a preparation method of carbonized modified slag mortar, which comprises the following steps:

s1, dissolving NaOH in water to prepare 8mol/L NaOH solution, standing for 24h for later use, and using the NaOH solution as an alkali activator;

s2, weighing NaOH solution, water and standard sand (purchased from Xiamen Aisiu standard sand Co., Ltd.) in the slag S3 and S1 prepared in the example 1 according to the mass ratio of 22.59:4.92:4.72:67.77 for later use;

s3, adding NaOH solution, water and standard sand in slag S3 and S1 into a JJ-5 type cement mortar stirrer, stirring for 1min at 140r/min, then stirring for 3min at 290r/min, pouring into a mold, curing for 24h in a cement concrete constant temperature and humidity standard curing box under the conditions of 20 ℃ and relative humidity of 100%, demolding, and continuing curing for 28 days in the standard curing box until testing.

Example 26

The embodiment of the present application provides a method for producing a carbonized modified slag mortar, which is similar to embodiment 25, except that the slag S6 produced in embodiment 2 is used in step S2 instead of the slag S3 produced in embodiment 1.

Example 27

The embodiment of the present application provides a method for producing a carbonized modified slag mortar, which is similar to embodiment 25, except that the slag S12 produced in embodiment 3 is used in step S2 instead of the slag S3 produced in embodiment 1.

Example 28

The example of the present application provides a method for producing a carbonized modified slag mortar, which is similar to example 25 except that the slag S24 produced in example 4 is used in step S2 instead of the slag S3 produced in example 1.

Example 29

The example of the present application provides a method for producing a carbonized modified slag mortar, which is similar to example 25 except that the slag S72 produced in example 5 is used in step S2 instead of the slag S3 produced in example 1.

Example 30

The embodiment of the present application provides a method for producing a carbonized modified slag mortar, which is similar to embodiment 25, except that the slag S168 produced in embodiment 6 is used in step S2 instead of the slag S3 produced in embodiment 1.

Comparative example 5

This comparative example provides a production method of a carbonized modified slag mortar, similar to example 25, except that the slag S0 produced in comparative example 1 was used in step S2 instead of the slag S3 produced in example 1.

Example 31

The embodiment of the application provides a preparation method of carbonized modified slag mortar, which comprises the following steps:

s1, preparation of a water glass solution: adding NaOH and water into industrial water glass with the modulus of 3.14, stirring until the solid is completely dissolved to obtain a water glass solution (marked as 1M-Wg) with the modulus of 1.0, sealing and standing for 24 hours for later use, wherein the pH value of the water glass solution is 13.94;

s2, weighing the water glass solution, water and standard sand (purchased from Xiamen Aisiu standard sand Co., Ltd.) in the slag S3 and S1 obtained in the embodiment 1 according to the mass ratio of 22.28:4.56:6.31:66.85 for later use;

s3, adding the water glass solution, water and standard sand in the slag S3 and S1 into a JJ-5 type cement mortar stirrer, stirring for 1min at 140r/min, then stirring for 3min at 290r/min, pouring into a mold, curing for 24h in a cement concrete constant temperature and humidity standard curing box at the temperature of 20 ℃ and the relative humidity of 100%, demolding, and continuing curing for 28 days in the standard curing box until testing.

Example 32

The example of the present application provides a method for producing a carbonized modified slag mortar, which is similar to example 31, except that the slag S6 produced in example 2 is used in step S2 instead of the slag S3 produced in example 1.

Example 33

The example of the present application provides a method for producing a carbonized modified slag mortar, which is similar to example 31, except that the slag S12 produced in example 3 is used in step S2 instead of the slag S3 produced in example 1.

Example 34

The example of the present application provides a method for producing a carbonized modified slag mortar, which is similar to example 31, except that the slag S24 produced in example 4 is used in step S2 instead of the slag S3 produced in example 1.

Example 35

The example of the present application provides a method for producing a carbonized modified slag mortar, which is similar to example 31, except that the slag S72 produced in example 5 is used in step S2 instead of the slag S3 produced in example 1.

Example 36

The embodiment of the present application provides a method for producing a carbonized modified slag mortar, which is similar to embodiment 31, except that the slag S168 produced in embodiment 6 is used in step S2 instead of the slag S3 produced in embodiment 1.

Comparative example 6

This comparative example provides a production method of a carbonized modified slag mortar, similar to example 31, except that the slag S0 produced in comparative example 1 was used in step S2 instead of the slag S3 produced in example 1.

Example 37

The embodiment of the application provides a preparation method of alkali-activated carbonized modified slag mortar, which comprises the following steps:

s1, preparation of a water glass solution: adding NaOH and water into industrial water glass with the modulus of 3.14, and stirring until the solid is completely dissolved to obtain a water glass solution (marked as 2M-Wg) with the modulus of 2.0, wherein the pH value of the water glass solution is 12.86;

s2, weighing the water glass solution, water and standard sand (purchased from Xiamen Aisiu standard sand Co., Ltd.) in the slag S3 and S1 obtained in the example 1 according to the mass ratio of 21.96:8.02:4.12:65.89 for later use;

s3, adding the water glass solution, water and standard sand in the slag S3 and S1 into a JJ-5 type cement mortar stirrer, stirring for 1min at 140r/min, then stirring for 3min at 290r/min, pouring into a mold, curing for 24h in a cement concrete constant temperature and humidity standard curing box at the temperature of 20 ℃ and the relative humidity of 100%, demolding, and continuing curing for 28 days in the standard curing box until testing.

Example 38

The embodiment of the present application provides a method for producing a carbonized modified slag mortar, which is similar to embodiment 37, except that the slag S6 produced in embodiment 2 is used in step S2 instead of the slag S3 produced in embodiment 1.

Example 39

The embodiment of the present application provides a method for producing a carbonized modified slag mortar, which is similar to embodiment 37, except that the slag S12 produced in embodiment 3 is used in step S2 instead of the slag S3 produced in embodiment 1.

Example 40

The embodiment of the present application provides a method for producing a carbonized modified slag mortar, which is similar to embodiment 37, except that the slag S24 produced in embodiment 4 is used in step S2 instead of the slag S3 produced in embodiment 1.

EXAMPLE 41

The example of the present application provides a method for producing a carbonized modified slag mortar, which is similar to example 37, except that in step S2, the slag S72 produced in example 5 is used in place of the slag S3 produced in example 1.

Example 42

The embodiment of the present application provides a method for producing a carbonized modified slag mortar, which is similar to embodiment 37, except that the slag S168 produced in embodiment 6 is used in step S2 instead of the slag S3 produced in embodiment 1.

Comparative example 7

This comparative example provides a production method of a carbonized modified slag mortar, which is similar to example 37, except that the slag S0 produced in comparative example 1 is used in step S2 instead of the slag S3 produced in example 1.

Performance testing

FIG. 1 is a view showing the morphology (shown as a in FIG. 1) of granulated blast furnace slag used before modification treatment in example 1 of the present application and a surface morphology (shown as b in FIG. 1) after sieving in step S1.

The setting time of the carbonized modified slag gelled materials prepared in examples 7 to 24 and comparative examples 2 to 4 is tested, and the result is shown in fig. 2, wherein the test method is determined by a vicat instrument with reference to national standard GB/T1346-2011 (test method for water demand for normal consistency, setting time and stability of portland cement).

FIG. 2 a) shows the setting times of the cement prepared from the raw materials of slag S0, slag S3, slag S6, slag S12, slag S24, slag S72 and slag S168 using NaOH solution as an activator in examples 7 to 12 and comparative example 2; b) in FIG. 2 shows the setting time of the cement prepared from the water glass solution having a modulus of 1.0, and from the raw materials of slag S0, slag S3, slag S6, slag S12, slag S24, slag S72 and slag S168 in examples 13 to 18 and comparative example 3; in FIG. 2 c) are shown setting times of cement prepared from the water glass solutions having a modulus of 2.0, slag S0, slag S3, slag S6, slag S12, slag S24, slag S72 and slag S168 in examples 19 to 24 and comparative example 4.

As can be seen from FIG. 2, the initial setting time and final setting time of the alkali-activated carbonized modified slag-binding material obtained were significantly prolonged as the modification time of the slag in the carbon dioxide atmosphere was longer. It should be noted that the glue prepared by using the freshly ground slag as the raw material and NaOH solution as the alkali activatorThe initial setting time of the setting material is 16min, and the initial setting time of the cementing material prepared by using water glass solution with modulus of 1.0 and 2.0 as alkali activator is 13min and 8 min. Early alkali-activated reactions of the slag are a diffusion-controlled process, and therefore the viscosity of the freshly alkali-activated slag slurry is a key factor in the coagulation. The fluidity of the NaOH solution-excited slag is lower than that of the water glass-excited slag. Therefore, the condensation speed of the water glass activated slag is faster under the same water-cement ratio. When the slag carbonization modification time was 168 hours, the initial setting time of the alkali-activated slag cement prepared using NaOH solution as an activator was extended to 134min, while the initial setting times of the alkali-activated slag cements prepared using water glass solutions having moduli of 1.0 and 2.0 were extended to 54min and 1167min, respectively. This is due to the fact that the highly reactive silicate monomer (Q0), "free" oxygen in the Ca-O-Ca-linkage and the singly fixed oxygen of ≡ Si-O-Ca-on the slag surface are converted into CaCO of low reactivity during carbonization₃Si-OH and a gel phase, and wrapping the carbonized slag surface to form a protective film. Carbonizing the protective film of low reactivity on the slag surface reduces the dissolution rate of the alkaline solution into the slag. In the initial stage, in order to maintain continuous hydration reaction of the slag in the alkali-activated slag, alkali ions (OH)^-) Chemical dissolution is required to be performed by diffusion into the slag through the protective film, and Ca, Si, and Al dissolved in the slag are diffused into the solution. The protective film product has strong chemical dissolution resistance, induces the alkali-activated slag slurry to enter a diffusion control process at the initial stage of dissolution, and has obvious influence on the alkali-activated reaction process of slag. Therefore, the setting time is prolonged. The setting time of the alkali-activated slag-binding material prepared using the NaOH solution and the water glass solution having a modulus of 1.0 as the alkali-activator is less prolonged as compared with the water glass solution having a modulus of 2.0. This is due to the OH content of the water glass solution with a modulus of 2.0^-Lower concentration, OH of the activator^-The higher the concentration, the faster the dissolution of the slag, the faster the formation of the product and the shorter the setting time.

The compressive strength of the carbonized-modified slag cements prepared in examples 25 to 42 and comparative examples 5 to 7 was tested, and the results are shown in fig. 3. Here, it is to be noted that: in the strength test, the alkali-activated carbonized modified slag mortar is subjected to a strength test with reference to GB/T17671-2020 Cement mortar Strength test method (IOS method).

In FIG. 3, the abscissa NaOH represents the compressive strength of the carbonized-modified slag cement prepared by adding standard sand to the raw materials of slag S0, slag S3, slag S6, slag S12, slag S24, slag S72, and slag S168 using NaOH solution as an activator in examples 25 to 30 and comparative example 5; the abscissa 1M in FIG. 3 shows the compressive strength of the carbonized-modified slag cement prepared by adding standard sand to the raw materials of slag S0, slag S3, slag S6, slag S12, slag S24, slag S72 and slag S168 in examples 31 to 36 and comparative example 6 using a water glass solution having a modulus of 1.0 as an activator; the abscissa 2M in FIG. 3 shows the compressive strength of the carbonized-modified slag cement prepared by adding standard sand to the raw materials of slag S0, slag S3, slag S6, slag S12, slag S24, slag S72 and slag S168 in examples 37 to 42 and comparative example 6 using a water glass solution having a modulus of 2.0 as an activator.

FIG. 3 shows the 28-day compressive strength of the carbonized-modified slag cements prepared with different activators. The compressive strength of the carbonized modified slag cement does not change significantly because the later strength (28 days) of the carbonized modified slag cement depends mainly on the formation and polymerization of the silicate structure. OH in the trigger^-The concentration is a key factor influencing the slag reaction, and under the condition that the ratio of the exciting agent to the water and the glue is kept unchanged, only the characteristics of the raw materials are different, namely the slag is exposed to CO₂Are different. Due to OH in the activator solution^-The concentration is higher, the impervious layer on the surface of the slag particles is dissolved, the reaction speed is accelerated, and a reaction product is generated. Therefore, the highly corrosive excitant solution can destroy the carbonization impervious layer on the surface of the carbonization slag particles before the carbonization modified slag cementing material is initially solidified. Once the carbonized layer is destroyed, the subsequent reactions are not affected, nor are the types and amounts of the main reaction products affected (see later section). Compared with the sodium hydroxide-excited carbonized modified slag cementing material, the sodium hydroxide-excited carbonized modified slag cementing material has higher compressive strength.

XRD patterns of the carbonized modified slag gelled materials prepared in the examples 7-24 and the comparative examples 2-4 are tested, and the results are shown in FIG. 4.

FIG. 4 a) shows XRD patterns of carbonized-modified slag cements prepared from slag S0, slag S3, slag S6, slag S12, slag S24, slag S72 and slag S168 using NaOH solution as an activator in examples 7 to 12 and comparative example 2; in FIG. 4 b) shows XRD patterns of the carbonized-modified slag cement prepared from examples 13 to 18 and comparative example 3 using water glass having a modulus of 1.0 as an excitant and using slag S0, slag S3, slag S6, slag S12, slag S24, slag S72 and slag S168 as raw materials; in FIG. 4 c) shows XRD patterns of the carbonized modified slag cement prepared from examples 19 to 24 and comparative example 4 using water glass having a modulus of 2.0 as an exciting agent and using slag S0, slag S3, slag S6, slag S12, slag S24, slag S72 and slag S168 as raw materials.

It can be seen from fig. 4 that the XRD patterns of all cement samples made from freshly ground slag and carbonized slag are similar when the same excitant is used. In all samples of carbonised modified slag cement, the strong reflection at 29.5 ° around 2 θ is clearly visible as calcite (CaCO)₃PDF #072-_1.5SiO_3.5·xH₂O, PDF # 033-. Hydrotalcite (Mg) was also found in NaOH-excited slag samples₆Al₂(CO₃)(OH)₁₆·4(H₂O), 11.5 DEG and 23 DEG peaks around 2 theta related to PDF #014-0191), but the peak intensity in the 1.0-model water glass solution-excited carbonized modified slag cement was low and disappeared in the 2.0-model water glass solution-excited carbonized modified slag cement. Because the hydrotalcite phase can only be stably present in the NaOH-activated carbonized modified slag cement with high aluminum concentration. A small amount of C-S-H (I) (2 theta is 7 degrees, PDF #034-0002) phase also exists in the NaOH-activated carbonized modified slag cementing material.

The XRD patterns of the modified slags of examples 1 to 6 and comparative example 1 were measured, and the results are shown in fig. 5.

In fig. 5, S3, S6, S12, S24, S72, S168, and S0 respectively show XRD patterns of the slag after the carbonization modification treatment in examples 1 to 6 and comparative example 1.

FTIR spectra of the modified slags of examples 1 to 6 and comparative example 1 were measured, and the results are shown in FIG. 6.

In fig. 6, S3, S6, S12, S24, S72, S168, and S0 represent FTIR spectra of modified slag in examples 1 to 6 and comparative example 1, respectively.

As can be seen from FIG. 5, CO₂The exposure time has no influence on the slag mineral composition. The characteristic peak of amorphous phase in the carbonized modified slag has obvious dispersion peak at 25-35 degrees of 2 theta.

As can be seen from the IR spectrum of FIG. 6, the slag concentration is about 970cm^-1The main absorption peak at (a) is not affected by carbonization. FIG. 8 shows the carbonized slag at 1490cm^-1、1420cm^-1、877cm^-1、853cm^-1And 713cm^-1The FTIR bands of (1) are changed, and the peaks are Carbonate (CO)₃ ^2-) Typical characteristic peaks of (a). At 1490cm^-1And 1420cm^-1The peak appeared here is the asymmetric stretching vibration peak of O-C-O in nepheline. At 877cm^-1And 713cm^-1Is a typical characteristic peak of calcite. 853cm^-1The peak of (a) is a characteristic peak of aragonite. 668cm with increasing carbonization time^-1The peak at (A) gradually disappears, and the peak belongs to SiO₄Or AlO₄The vibration peaks of tetrahedrons. Here, it is the most reactive silicate group (Q)₀) Because chemical bonds in the slag are broken during the mechanical ball milling process, SiO is formed₄And/or AlO₄A tetrahedral monomer.

Thermogravimetric analysis graphs of the modified slags of examples 1 to 6 and comparative example 1 were tested, and the results are shown in fig. 7.

In fig. 7, S3, S6, S12, S24, S72, S168, and S0 represent thermogravimetric analysis charts of modified slags in examples 1 to 6 and comparative example 1, respectively.

Thermogravimetric analysis for determining CaCO in carbonized slag₃Various forms exist. The results show that: with slag in CO₂Time delay of exposureLong, amorphous calcium carbonate is formed first, followed by the formation of a metastable state. These results are consistent with FTIR analysis results. In addition, exposure to CO₂CO of 168h slag in atmosphere₂The absorption amount was 0.33mmol_CO2/g_slag。

XPS spectra of the modified slags of examples 1 to 6 and comparative example 1 were measured, and the results are shown in fig. 8.

In FIG. 8, (a) shows Ca 2p spectra of modified slags of examples 1 to 6 and comparative example 1, (b) shows C1s spectra of modified slags of examples 1 to 6 and comparative example 1, (C) shows O1s spectra of modified slags of examples 1 to 6 and comparative example 1, and (d) shows Si 2p spectra of modified slags of examples 1 to 6 and comparative example 1.

The surface composition analysis of the modified slag of examples 1 to 6 and comparative example 1 is shown in Table 2.

TABLE 2 surface composition of modified slag in different examples

As can be seen from FIG. 8, the Ca 2p peaks of the freshly ground slag (i.e., S0) consisted of states 2p3/2 and 2p1/2, with binding energies of 346.3 and 349.8eV, respectively (FIG. 8 (a)). The binding energies of the carbonized modified slag and the carbonized modified slag occur at 346.7eV and 350.2 eV. Compared with the newly ground slag, the Ca 2p binding energy in the carbonized slag is integrally increased, which shows that the chemical environment of Ca in the carbonized slag is obviously changed. This may be due to CaCO₃And a calcium containing gel phase.

Fig. 8(b) is a C1s signal before and after slag carbonization. The binding energies of C1s around 283.9eV that were present in all samples were assigned to exogenous carbons. The major peak at 288.9eV is Carbonate (CO)₃ ^2-) Belonging to CaCO₃. This result is consistent with the above analysis (e.g., FTIR). The reactivity of slag is closely related to the form of oxygen present in slag, such as double-fixed oxygen in the bond of ≡ Si-O-Si ≡ (≡ Si-O-Al ≡), single-fixed oxygen in the bond of ≡ Si-O-Ca, and single-fixed oxygen in the bond of-Ca-O-CaThe "free" oxygen in (1) and the hydrate form exist, and the Ca-O bond is weaker than the Al-O and Si-O bonds. As can be seen from FIG. 8(c), the slag is in CO₂After exposure, the O1s binding energy of the slag rose from 530.6eV to 531.0 eV. This result indicates that the chemical state of the slag surface oxygen has changed.

The O1s spectra of the modified slag of examples 1 to 6 and comparative example 1 were fitted as shown in fig. 9, and the fitting parameters of the O1s spectra were summarized as shown in table 3.

TABLE 3 fitting parameters of spectrogram of O1s

The fitted peak at 530.8-531.2eV is the typical binding energy of calcium oxide species, assigned to different CO₂The "free" oxygen in the-Ca-O-Ca-bond and the singly fixed oxygen in the ≡ Si-O-Ca bond in the slag under exposure time. Furthermore, as can be seen from Table 2, as the slag is in CO₂The Ca-O bond content on the surface of the slag is obviously reduced due to the increase of the exposure time. Meanwhile, the other two peaks having higher binding energy (. ident.Si-O-Al. ident.) are typical binding energies of oxygen, which are attributed to the ≡ Si-O-Si ≡ (ident.Si-O-Al ≡) bond and the silanol (Si-OH) group in the slag. The contents of the ≡ Si-O-Si ≡ (≡ Si-O-Al ≡) bond and Si-OH group in the carbonized slag as compared with freshly ground slag₂The exposure time in the atmosphere increases. The reduction of Ca-O bonds and the increase of Si-OH groups and of the-Si-O-Si-I.ident (. ident.Si-O-Al-ident.) bands can be explained by the following equations:

≡Si-O-Ca-O-Si≡+H₂O+CO₂→2≡Si-OH+CaCO₃

≡Si-O-Ca…O…Ca-O-Si≡+H₂O+2CO₂→2≡Si-OH+2CaCO₃

when the Si-OH groups accumulated on the slag surface reach a critical value, these groups will dehydrate and polymerize to form a ≡ Si-O-Si ≡ bond, increasing the double anchoring oxygen bond, as shown in Table 3.

FIG. 8(d) shows different COs₂Si 2p binding energy of the slag at exposure time. As is clear from FIG. 11(d), with CO₂The longer the exposure time, the higher the binding energy of the Si 2p, due to the formation of more Si-OH groups on the slag surface. The lower Ca/Si ratio (see Table 2) with calcium as a charge balancing ion means that there is less silicate tetrahedral residue remaining with a negative surface charge, resulting in less dominance of Ca-O-Si bonds and more Si-OH formed.

Summary of the invention

Ca-O bonds in the slag particles in the freshly ground slag cementitous material are weaker than Al-O and Si-O bonds and therefore in OH^-In the activator solution with higher concentration, Ca-O bond is firstly broken. When water glass is used as an excitant, calcium ions dissolved from slag and silicate ions in the solution quickly react to form C-S-H gel, and a large amount of heat is released, so that the alkali-activated carbonized modified slag cementing material is quickly solidified. When the activator is NaOH solution only, high concentration OH in liquid phase^-The ions destroy not only Ca-O bonds but also a large amount of Al-O bonds and Si-O bonds in the slag particles. Therefore, Ca dissolved from the slag reacts with the dissolved (aluminate) silicate ions to form C- (A) -S-H precipitates, resulting in rapid solidification of the slag excited by the NaOH solution. FTIR and XPS analysis indicate the presence of large amounts of highly active components, such as SiO, in the new slag₄The monomers (Q0), "free" oxygen in the-Ca-O-Ca-linkage and a single fixed oxygen in the-Si-O-Ca-linkage. When the slag is contacted with the activator solution, these active components will hydrate rapidly and form early precipitation products which will solidify rapidly.

Carbonized modified slag cementing material

The results clearly show that the setting time of the alkali-activated slag cement produced from carbonized slag is significantly prolonged compared to the initial setting time of the alkali-activated carbonized modified slag cement produced from freshly ground slag with unchanged control of experimental conditions such as the kind and dosage of the exciting agent, the water-to-solid ratio, the temperature and the humidity. The surface characteristics of the carbonized slag are the main cause of the prolongation of the initial setting time.Exposure to CO₂Then Ca and H with higher surface reactivity of slag₂O and CO₂Reaction to form CaCO₃. In addition, carbonization of the slag also causes a change in the chemical state around Si. First, Si-O and Al-O bonds on the surface of slag are exposed to CO under humidity conditions₂In (2), more hydroxyl groups are formed. High activity silicate monomer (Q) on the surface of new grinding slag₀) The "free" oxygen in the-Ca-O-Ca-bond and the single fixed oxygen in the ≡ Si-O-Ca-bond are converted during carbonization into less reactive CaCO₃Si-OH, and a gel phase. This low reactivity protective film results in slow dissolution of the slag in the early stages. Similar to the silicate cement hydration reaction model, the hydration reaction curve of the carbonized modified slag cementing material can also be divided into five stages. Specifically, normalized cumulative exothermic curves of alkali-activated slag reaction for 5000 minutes under different activators are shown in FIG. 10, wherein a) in FIG. 10 shows the cumulative exothermic curves of carbonized-modified slag cements prepared from slag S0, slag S6, slag S24 and slag S168 using NaOH solution as the activator and slag S0, slag S6, slag S24 and slag S168 as the raw materials in examples 8, 10 and 12 and comparative example 2; b) shows cumulative exothermic curves of carbonized-modified slag cements prepared from slag S0, slag S6, slag S24 and slag S168 as raw materials using a water glass solution having a modulus of 1.0 as an excitant in examples 14, 16 and 18 and comparative example 3; c) shows the cumulative exothermic curves of the carbonized-modified slag cements produced from the starting materials of slag S0, slag S6, slag S24 and slag S168 using a water glass solution having a modulus of 2.0 as an excitant in example 20, example 22, example 24 and comparative example 4.

The testing method of the hydration reaction heat release curve of the carbonized modified slag cementing material comprises the following steps: the temperature rise of the slag cementing material in the early hydration reaction process is measured by adopting a semi-adiabatic calorimetry, and the hydration reaction process of the slag cementing material is qualitatively analyzed. 200.00g of slag (i.e., corresponding slag S0, slag S6, slag S24, slag S168) was weighed, and then a desired activator solution (i.e., corresponding NaOH solution, water glass solution having a modulus of 1.0, water glass solution having a modulus of 2.0) and water were added in proportion, and mixed for 3min with a disperser: stirring was carried out at 400 rpm for 1min and then at 1000 rpm for 2 min. The homogeneous slag slurry was immediately transferred to a 450ml vacuum glass tank for testing. The temperature change of the first 5000 minutes was recorded using a p-n junction temperature sensor with an accuracy of 0.1 ℃.

As can be seen from fig. 10, the hydration curve of the carbonized modified slag cement occurs at a distinct stage before the Initial reaction period (IP), as shown in fig. 10, referred to as Pre-Initial reaction period (PIP). Due to the presence of the carbonized protective film, when the carbonized slag contacts the activator solution, the alkali-activated slag enters the PIP. The reactivity characteristics of different activators on slag in PIP are discussed in detail below:

when the activating agent is NaOH solution, the active Ca on the slag surface is converted into inactive CaCO during carbonization₃High concentration of OH^-The solution can destroy only Al-O bonds and Si-O bonds on the surface of the carbonized slag. Due to the lack of Ca in the solution²⁺And no gel phase precipitate can be formed. At this point, the hydration process of the carbonized modified slag cement is still in PIP, the longer the PIP duration, the longer the initial setting time. Once the carbonization protective layer is damaged, PIP of hydration reaction of the carbonization modified slag cementing material is finished, and the reaction enters IP, which is consistent with the initial stage of hydration reaction of the freshly ground slag. The initial setting time of NaOH activated carbonized slag cement and the PIP time increased with increasing carbonization time. On the one hand, as the carbonation time of slag increases, the thickness of the carbonized slag protective film increases, OH-in the solution is dissolved and Ca is released²⁺More time is required. On the other hand, the dissolution rate of Al in the NaOH system is faster than that of Si and Ca, resulting in formation of a Si-rich layer on the surface of the carbonized slag (Ca in the carbonized layer is insoluble). The dissolved Al is absorbed to the surface of the silicon rich layer to form a passivation protective layer again, inhibiting the dissolution of the carbonized slag.

When the activator is a 1.0-modulus water glass solution, no PIP is evident during the reaction of the carbonized slag cement. As can be seen from the slope of the response curve (fig. 10), the reaction rate in the IP phase decreases. Although the carbonization depth of slag increases with the carbonization time, OH at a high concentration^-In the next place, the aluminosilicate glass structure in the slag carbonized layer can be rapidly dissolved to form Al monomer. Unlike the NaOH system, the Al monomer dissolved from the carbonized slag reacts with the water-soluble Na-polysiloxane in the water glass to produce Si-O-Al oligomer, reducing the Al concentration in the solution, thereby promoting the slag forward dissolution reaction. Furthermore, the viscosity of water glass-activated slag is lower than that of NaOH system, which results in increased diffusion speed of ions in alkali-activated slag, thereby increasing the dissolution speed of slag. Once the protective film is broken, Ca²⁺Can be dissolved rapidly because in the water glass system, the Ca-O bond is broken first.

When the activator is a 2.0 model water glass solution, a distinct PIP stage appears on the reaction curve. The OH-concentration in the 2.0 model water glass solution was lower than that of the 1.0 model water glass solution and NaOH solution. An inactive protective film is present on the surface of the carbonized slag to make the carbonized slag to OH in the solution^-And is more sensitive. Relatively low OH when the carbonized slag contacts the 2M-Wg solution^-The concentration takes a long time to dissolve the aluminosilicate phase in the carbonized slag protective film. Therefore, the PIP stage of 2.0 mold water glass solution-initiated carbonized slag is longer than that of NaOH solution-initiated carbonized slag.

In view of the above, the present application proposes for the first time a method of pretreating slag by carbonization to control the setting time of alkali-activated slag. The carbonization of the slag not only can trap carbon dioxide but also can control the coagulation time of the alkali-activated slag produced by carbonizing the slag without affecting other properties. The main conclusions were drawn as follows:

(1) after carbonization, the physicochemical property of the slag is obviously changed, and a protective layer with low reactivity is formed on the surface of the slag. Firstly, soluble Ca on the surface of the slag is converted into insoluble CaCO₃With slag in CO₂Increased exposure time to produce CaCO₃The amount of (c) increases. Secondly, the chemical state around Si and O on the surface of the carbonized slag changes. The slag is reduced in the "free" oxygen in the-Ca-O-Ca-linkage and in the single fixed oxygen in the-Si-O-Ca-linkage under carbonization, and increased in the double fixed oxygen in the-Si-O-I (. ident.Si-O-Al. ident.) linkage.

(2) Slag carbonization can effectively prolong the setting time of the carbonized slag cementing material. In addition, the coagulation time can be controlled by adjusting the exposure time of the slag to carbon dioxide. NaOH solution, 1.0 model water glass and 2.0 model water glass are excited in CO₂The initial setting time of the slag after 168 hours of the exposure is respectively prolonged to 134min, 54min and 1167 min.

(3) The hydration reaction curve of the carbonized slag cement shows a significantly lower reaction stage before the induction period compared to freshly ground slag. During this time, the dissolution rate of the aluminosilicate structure in the slag carbonized layer is low, and once the carbonized layer is broken, the carbonized slag undergoes the same hydration reaction process as that of the freshly ground slag.

(4) The prepared carbonized slag cementing material can be controlled within a reasonable initial setting time range by the carbonized slag, and the compressive strength and reaction products of the alkali-activated slag mortar are not influenced by the carbonized slag.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.