Method for establishing relationship between carbonation performance and carbonation structure of low-carbon clinker

Abstract

This invention discloses a method for establishing the relationship between the carbonization performance and carbonization structure of low-carbon clinker, comprising the following steps: 1) determining the optimal water-cement ratio w / c and the corresponding molding amount c of the low-carbon clinker using a pressing molding method; 2) performing pressing molding, drying, carbonization curing, and measuring the compressive strength σ of the obtained carbonization product based on the determined w / c and c. c and carbon fixation rate r c 3) Calculate the volume percentage W of CaCO3 formed after carbonization. VCaCO3 The volume percentage of the remaining low-carbon clinker W Vc Then calculate the total volume ratio W between the two. 总 ;4) Establish compressive strength σ c Percentage of total volume W 总 The present invention establishes a stoichiometric relationship between the carbonization performance and carbonization structure of low-carbon clinker. This relationship directly reflects the carbonization performance of low-carbon clinker and can be used to guide the efficient application of different types of low-carbon clinker, making it suitable for widespread application.

Description

Technical Field

[0001] This invention belongs to the field of building materials analysis technology, specifically relating to a method for establishing the relationship between the carbonization performance and carbonization structure of low-carbon clinker. Background Technology

[0002] Low-carbon clinker can be produced directly using existing raw materials and equipment in the cement industry. Its main mineral composition consists of low-calcium minerals C3S2, CS, β-C2S, and γ-C2S. Compared with silicate cement clinker, which is mainly composed of C3S minerals, it requires less limestone in its batching and has a lower calcination temperature. This can reduce carbon emissions from the cement industry and absorb a large amount of CO2 gas, thereby producing building materials with excellent physical properties.

[0003] The carbonization properties of low-calcium minerals C3S2, CS, β-C2S, and γ-C2S are different, and under low calcium-silicon ratio, calcining low-carbon clinker inevitably results in different contents of C2AS and C2MS2. Low-carbon clinker is usually composed of one or more of these minerals in different contents, activities, densities, and fineness, resulting in a wide variety of low-carbon clinker with unstable performance. Each type of low-carbon clinker requires specific molding and carbonization conditions to fully realize its carbonization performance.

[0004] Under relatively uniform carbonization conditions, the carbonization strength and carbon fixation rate of the same type of low-carbon clinker are correlated; that is, the higher the carbon fixation rate, the higher the carbonization strength. Each carbon fixation rate corresponds to a carbonization strength. However, due to variations in the types of low-carbon clinker, the carbon fixation rate required to achieve the same carbonization strength varies, making it impossible to effectively integrate different types of low-carbon clinker for guiding their application. How to integrate different types of low-carbon clinker, identify their correlations, and intuitively reflect the carbonization performance of low-carbon clinker to promote its efficient application has become an urgent technical problem to be solved. Summary of the Invention

[0005] The main objective of this invention is to provide a method that can intuitively reflect the relationship between the carbonization performance and structure of low-carbon clinker. By constructing a stoichiometric relationship between the carbonization performance and carbonization structure of low-carbon clinker, the carbonization performance of low-carbon clinker can be intuitively reflected, and it can be used to guide the efficient application of different types of low-carbon clinker.

[0006] To achieve the above objectives, the following technical solution is adopted:

[0007] A method for establishing the relationship between the carbonization performance and carbonization structure of low-carbon clinker includes the following steps:

[0008] 1) The optimal water-cement ratio w / c and the corresponding molding amount c for low-carbon clinker were determined by compression molding method;

[0009] 2) Based on the determined optimal water-cement ratio w / c and molding amount c, the low-carbon clinker is pressed into shape, and the apparent volume V of the resulting specimen is recorded. 表观 The products were dried to different moisture contents, then carbonized and cured. The compressive strength σ of the carbonized products obtained under different moisture contents was measured. c and carbon fixation rate r c And calculate the volume V of CaCO3 formed after carbonization. CaCO3 The volume V of the remaining low-carbon clinker after carbonization c ;

[0010] 3) Calculate the volume V of the formed low-carbon clinker based on the parameters determined above. c0 The volume percentage W of CaCO3 formed after carbonization VCaCO3 The volume percentage of low-carbon clinker remaining after carbonization, W Vc The total volume percentage of CaCO3 and residual low-carbon clinker formed after carbonization is W. 总 ;

[0011] 4) Establish the compressive strength σ after carbonization c The total volume percentage W of CaCO3 formed after carbonation and the remaining cement clinker 总 The stoichiometric relationship between them.

[0012] In the above scheme, the method for determining the optimal water-cement ratio w / c and molding amount c includes: using a compression molding method, pressing low-carbon clinker into molding samples of the same specifications with different water-cement ratios under the same molding pressure conditions; selecting the maximum water-cement ratio that will not be squeezed out as the optimal water-cement ratio, and the mass of low-carbon clinker contained in the sample at this time is the molding amount of the low-carbon clinker.

[0013] Furthermore, the molding pressure can be selected from 5 to 20 MPa, and the holding time is 30 to 60 seconds.

[0014] Furthermore, the molded specimen is preferably a cylindrical specimen, with a corresponding diameter or height error not exceeding 1%.

[0015] Preferably, the molded sample is a small cylindrical sample with a diameter of 1 to 10 cm and a height of 1 to 10 cm.

[0016] In the above scheme, the moisture content in step 2) is 0-20%, and the interval between two adjacent moisture contents is 0-3% (excluding 0%).

[0017] In the above scheme, the carbonization curing is carried out under the conditions of CO2 concentration of 15-100%, temperature of 20-70℃, humidity of 50-90%, and air pressure of 0.1-0.6MPa for 8-72 hours.

[0018] In the above scheme, the apparent volume V of the cylindrical forming specimen is... 表观 =π*r 2 *h; where r is the radius of the cylindrical specimen and h is the height of the cylindrical specimen, both in cm.

[0019] In the above scheme, the volume V of the formed low-carbon clinker c0 =c / ρ c Where c is the molding amount, in grams; ρ c The density of low-carbon clinker, in g / cm³ 3 The density was measured using a true density meter.

[0020] In the above scheme, the volume V of CaCO3 formed after carbonization CaCO3 =c*r c *100 / (44*ρ CaCO3 ), where c is the molding amount, in grams; r c To determine the carbon fixation rate, ρ CaCO3 The density of CaCO3 is 2.6–2.8 g / cm³. 3 .

[0021] In the above scheme, the volume V of the remaining low-carbon clinker after carbonization c =V c0 -[c*r c *56 / (44*ρ CaO ]], where c is the molding amount in grams; r c To determine the carbon fixation rate, ρ CaO The density of CaO is 3.25–3.38 g / cm³. 3 .

[0022] In the above scheme, the volume percentage W of CaCO3 formed by carbonization is... VCaCO3 =V CaCO3 / V 表观 The volume percentage of low-carbon clinker remaining after carbonization, W Vc =V c / V 表观 The total volume percentage W after carbonization 总 =W VCaCO3 +W Vc .

[0023] In the above scheme, step 4) establishing the relationship between carbonization intensity and the total volume ratio after carbonization is based on the low-carbon clinker being dried to different moisture contents and then fitted to obtain W. 总 -σ c To avoid the effects of uneven carbonization on the carbide, a trend line with σ should be selected. c Less than the maximum value and r cData not exceeding 90% of the maximum carbon fixation rate, with a goodness of fit R. 2 It should be no less than 0.9.

[0024] In the above scheme, the W 总 -σ c The trend line is a linear trend line determined using the least squares method.

[0025] In the above scheme, the main chemical components and their mass percentages in the low-carbon clinker include: CaO 40-60%, SiO2 30-50%, Al2O3 0-5%, Fe2O3 0-5%, and MgO 0-5%.

[0026] Furthermore, the relationship between the carbonization performance and carbonization structure of the low-carbon clinker described in this invention is specifically the compressive strength σ. c The relationship between structural features and the proportion of CaCO3 formed after carbonation and the total volume of remaining cement clinker.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] (1) The essence of carbonization strength is the process by which low-carbon clinker carbonizes to form CaCO3, increasing its volume and filling the pores. Ultimately, this makes the specimen increasingly dense, resulting in higher strength. The strength mainly comes from the remaining uncarbonized low-carbon clinker and the CaCO3 formed after carbonization. Linking the carbonization performance of low-carbon clinker with its carbonization structure can intuitively reflect its carbonization performance and can be used to guide the application of different types of low-carbon clinker, solving the problem that the relationship between carbonization strength and carbon fixation rate cannot be established between different types of low-carbon clinker.

[0029] (2) The optimal water-cement ratio is determined for the first time based on the pressing molding method. This method can improve the molding density of low carbon clinker under the same molding pressure, thereby effectively improving the carbonization strength and helping to better establish the relationship between the carbonization performance and structure of low carbon clinker.

[0030] (3) The data selected for establishing the relationship is relatively accurate: Carbonation requires water as Ca. 2+ The medium for dissolution and CO2 dissolution is water, but water is continuously lost during carbonization. As the water content increases before carbonization, the effective carbonization time is extended due to the longer water presence time, which can improve the carbon fixation rate to a certain extent. However, too much water will block the pores, preventing CO2 from quickly diffusing into the interior, resulting in uneven carbonization inside and outside the sample. Therefore, the carbonization is usually not uniform when the carbonization intensity and carbon fixation rate are the highest. This invention further selects data with carbonization intensity less than the maximum value and carbon fixation rate not exceeding 90% of the maximum carbon fixation rate for fitting.

[0031] (4) In addition to showing the relationship between carbonization intensity and the total volume ratio after carbonization, the established trend line can also reflect the uniformity of carbonization to a certain extent: if it is below the trend line, it indicates that there is enough carbonization but low intensity, and there are problems such as uneven carbonization. It is necessary to adjust the molding conditions and carbonization conditions, or because the low carbon clinker used is easy to compact, the molding amount is too high, resulting in too much uncarbonized low carbon clinker and too little actual carbonization. It is necessary to adjust the calcination preparation conditions of low carbon clinker; if it is above the trend line, it indicates that a better formula or process condition has been adopted, which makes the carbonization more uniform. The cause can be found in time based on this phenomenon, and further guidance and optimization of the corresponding formula or process condition can be carried out. Attached Figure Description

[0032] Figure 1 The W obtained by fitting the schemes described in Examples 1 to 4 respectively 总 -σ c Trend line.

[0033] Figure 2 The total W obtained by integrating and fitting the data described in Examples 1-4 总 -σ c Trend line.

[0034] Figure 3 The W obtained by fitting the schemes described in Comparative Example 1 and Examples 2-3 respectively 总 -σ c Trend line.

[0035] Figure 4 W obtained by fitting the scheme described in Comparative Example 2 总 -σ c Trend line. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0037] The following embodiments further illustrate the technical solution of the present invention, but are not intended to limit the scope of protection of the present invention.

[0038] In the following examples, the density ρ of CaO is... CaO The value is 3.3 g / cm³. 3 The density ρ of CaCO3 formed by carbonization CaCO3 The value is 2.7 g / cm³. 3 .

[0039] Different types of low-carbon clinker were obtained. The chemical composition and density ρ of the low-carbon clinker used in the embodiments of the present invention were as follows: cAs shown in Table 1, grinding to R45μm ≤20% is required:

[0040] Table 1 Chemical composition and density of low-carbon clinker

[0041] name CaO / % <![CDATA[SiO2 / %]]> <![CDATA[Al2O3 / %]]> <![CDATA[Fe2O3 / %]]> MgO / % <![CDATA[ρ c / (g / cm 3 )]]> Low-carbon clinker 1 54.94 34.36 3.39 2.79 2.18 3.15 Low-carbon clinker 2 49.85 40.53 3.09 2.55 2.12 2.99 Low-carbon clinker 3 50.02 39.74 3.15 2.27 2.46 3.13 Low-carbon clinker 4 54.33 33.55 3.31 1.85 3.53 3.24

[0042] Example 1

[0043] A method for establishing the relationship between the carbonization performance and structure of low-carbon clinker includes the following steps:

[0044] 1) Low-carbon clinker 1 was pressed into cylindrical samples with a diameter of 2 cm and a height of 2 cm at a molding pressure of 10 MPa for 30 s with different water-cement ratios (water-cement ratio 0.10-0.30, with an interval of 0.01 between each water-cement ratio; the same below). The maximum water-cement ratio that would not be squeezed out was selected as the optimal water-cement ratio. The optimal water-cement ratio w / c of ​​low-carbon clinker 1 was determined to be 0.19. The mass of low-carbon clinker 1 contained in the sample at this time is the molding amount of the low-carbon clinker. The molding amount c was measured to be 11.4 (g).

[0045] 2) Using the above-mentioned low-carbon clinker, according to the optimal water-cement ratio, molding amount c, cylindrical specimen specifications, and molding process parameters obtained in step 1), 6 specimens (apparent volume V of the specimen block) were molded. 表观 =π*1 2 *2=6.283cm 3 The carbonized products were then dried under natural conditions to different moisture contents: 6.48%, 7.66%, 8.66%, 10.38%, 11.90%, and 13.36%. Finally, they were carbonized for 20 hours under conditions of 100% carbon dioxide concentration, 30℃ temperature, 60% humidity, and 0.4MPa pressure. The compressive strength σ of the carbonized products obtained under different moisture content conditions was then measured. c and carbon fixation rate r c The specific test results are shown in Table 2:

[0046] Table 2 Compressive strength and carbon fixation rate

[0047]

[0048] 3) Calculate the volume V of the formed low-carbon clinker. c0 =c / ρ c The volume V of CaCO3 formed by carbonization CaCO3 =c*r c *100 / (44*ρ CaCO3 The volume V of the low-carbon clinker that has not been hydrated after carbonization c =V c0 -[c*r c *56 / (44*ρ CaOThe volume percentage of CaCO3 formed by carbonization, W VCaCO3 =V CaCO3 / V 表观 The volume percentage of low-carbon clinker after carbonization (W) Vc =V c / V 表观 The total volume ratio of CaCO3 and low-carbon clinker formed after carbonization is W. 总 =W VCaCO3 +W Vc The calculated data are shown in Table 3:

[0049] Table 3 Data Calculation Results

[0050]

[0051] 4) Select the first four sets of data from the six sets in Table 3 (select data with carbonization intensity less than the maximum value of 154.89 MPa and carbon fixation rate not exceeding 20.691% (22.99% * 90%)) to establish W. 总 -σ c The trend line obtained is σ. c =819.39*W 总 -481.91, R 2 =0.9754, indicating a good fit.

[0052] Example 2

[0053] A method for establishing the relationship between the carbonization performance and structure of low-carbon clinker includes the following steps:

[0054] 1) Low-carbon clinker 2 was pressed into cylindrical samples with a diameter of 2cm and a height of 2cm under a molding pressure of 10MPa for 30s with different water-cement ratios. The maximum water-cement ratio that would not cause water to be squeezed out was selected as the optimal water-cement ratio. The optimal water-cement ratio w / c of ​​low-carbon clinker 2 was determined to be 0.20. The mass of low-carbon clinker 2 contained in the sample at this time is the molding amount of the low-carbon clinker. The molding amount c was measured to be 10.8 (g).

[0055] 2) Using the above-mentioned low-carbon clinker, according to the optimal water-cement ratio, molding amount c, cylindrical specimen specifications, and molding process parameters obtained in step 1), 6 specimens (apparent volume V of the specimen block) were molded. 表观 =π*1 2 *2=6.283cm 3The carbonized products were then dried under natural conditions to different moisture contents: 7.73%, 10.03%, 12.01%, 13.58%, 14.48%, and 15.81%. Finally, they were carbonized for 20 hours under conditions of 100% carbon dioxide concentration, 30℃ temperature, 60% humidity, and 0.4MPa pressure. The compressive strength σ of the carbonized products obtained under different moisture content conditions was then measured. c and carbon fixation rate r c The specific test results are shown in Table 4:

[0056] Table 4 Compressive strength and carbon fixation rate

[0057]

[0058] 3) Using the same method as described in Example 1, the calculated data are shown in Table 5:

[0059] Table 5 Data Calculation Results

[0060]

[0061]

[0062] 4) Select the first four groups of data from the six groups in Table 5 and establish W. 总 -σ c Trend line, the trend line is σ c =935.2*W 总 -564.55, R 2 =0.9788, indicating a good fit.

[0063] Example 3

[0064] A method for establishing the relationship between the carbonization performance and structure of low-carbon clinker includes the following steps:

[0065] 1) Low-carbon clinker 3 was pressed into cylindrical samples with a diameter of 2cm and a height of 2cm under a molding pressure of 10MPa for 30s with different water-cement ratios. The maximum water-cement ratio that would not cause water to be squeezed out was selected as the optimal water-cement ratio. The optimal water-cement ratio w / c of ​​low-carbon clinker 3 was determined to be 0.18. The mass of low-carbon clinker 3 contained in the sample at this time is the molding amount of the low-carbon clinker. The molding amount c was measured to be 11.3 (g).

[0066] (2) Using the above-mentioned low-carbon clinker, according to the optimal water-cement ratio, molding amount c, cylindrical specimen specifications and molding process parameters obtained in step 1), 6 specimens (apparent volume V of the specimen block) were molded. 表观 =π*1 2 *2=6.283cm 3The carbonized products were then dried under natural conditions to different moisture contents: 5.78%, 7.65%, 9.45%, 11.32%, 12.15%, and 13.49%. Finally, they were carbonized for 20 hours under conditions of 100% carbon dioxide concentration, 30℃ temperature, 60% humidity, and 0.4MPa pressure. The compressive strength σ of the carbonized products obtained under different moisture content conditions was then measured. c and carbon fixation rate r c The specific test results are shown in Table 6:

[0067] Table 6 Compressive strength and carbon fixation rate

[0068]

[0069] 3) Using the same method as described in Example 1, the calculated data are shown in Table 7:

[0070] Table 7 Data Calculation Results

[0071]

[0072] 4) Select the first four groups of data from the six groups in Table 7 and establish W. 总 -σ c Trend line, the trend line is σ c =891.54*W 总 -534.5, R 2 =0.9705, indicating a good fit.

[0073] Example 4

[0074] A method for establishing the relationship between the carbonization performance and structure of low-carbon clinker includes the following steps:

[0075] 1) Low-carbon clinker 4 was pressed into cylindrical samples with a diameter of 2cm and a height of 2cm at a molding pressure of 10MPa for 30s with different water-cement ratios. The maximum water-cement ratio that would not cause water to be squeezed out was selected as the optimal water-cement ratio. The optimal water-cement ratio w / c of ​​low-carbon clinker 4 was determined to be 0.14. The mass of low-carbon clinker 4 contained in the sample at this time is the molding amount of the low-carbon clinker. The molding amount c was measured to be 12.7 (g).

[0076] 2) Using the above-mentioned low-carbon clinker, according to the optimal water-cement ratio, molding amount c, cylindrical specimen specifications, and molding process parameters obtained in step 1), 6 specimens (apparent volume V of the specimen block) were molded. 表观 =π*1 2 *2=6.283cm 3The carbonized products were then dried under natural conditions to different moisture contents: 4.74%, 5.92%, 7.47%, 8.76%, 10.05%, and 11.57%. Finally, they were carbonized for 20 hours under conditions of 100% carbon dioxide concentration, 30℃ temperature, 60% humidity, and 0.4MPa pressure. The compressive strength σ of the carbonized products obtained under different moisture content conditions was then measured. c and carbon fixation rate r c The specific test results are shown in Table 8:

[0077] Table 8 Compressive strength and carbon fixation rate

[0078]

[0079] 3) Using the same method as described in Example 1, the calculated data are shown in Table 9:

[0080] Table 9 Data Calculation Results

[0081]

[0082] 4) Select the first four groups of data from the six groups in Table 9 and establish W. 总 -σ c Trend line, the trend line is σ c =954.21*W 总 -577.97, R 2 =0.9224, indicating a good fit.

[0083] W in each embodiment 总 -σ c Trend lines, for example Figure 1 As shown, in addition to the good linear relationship between the same type of low-carbon clinker, there is also a good linear relationship between different types of low-carbon clinker in each embodiment. By integrating the data selected from low-carbon clinker 1, 2, 3, and 4 in each embodiment, the total W can be established. 总 -σ c Trend lines, such as Figure 2 As shown, the overall trend line is σ. c =887.5*W 总 -531.52, R 2 =0.9828, indicating a good fit; linking the carbonization performance and carbonization structure of low-carbon clinker can intuitively reflect its carbonization performance and guide the application of different types of low-carbon clinker. That is, regardless of the type of low-carbon clinker used, what initial molding density, carbon fixation rate, and final volume filling and porosity are required to achieve the corresponding carbonization strength? For example, the carbon fixation rate of low-carbon clinker can usually exceed 20% under the conditions of this experiment. In Example 4, the molding volume V of low-carbon clinker 4... c0 =3.92g / cm3 It is higher than that of Examples 1, 2, and 3, and the carbon fixation rate r corresponding to its highest carbonization intensity is higher. c The carbon fixation rate was 15.75%, lower than in Examples 1, 2, and 3. The main reason for this was the insufficient initial space left for CaCO3 filling, resulting in a lower carbon fixation rate r. c When the carbonization content is 15.75%, the total volume percentage W after carbonization is... 总 The carbon fixation rate has reached 76-77%. At this point, the carbide is very dense, making it difficult for CO2 to diffuse into the sample. To improve the carbon fixation rate of low-carbon clinker 4, methods such as coarsening the low-carbon clinker 4 or lowering the calcination temperature for preparing low-carbon clinker 4 can be used to reduce the volume V of the formed low-carbon clinker. c0 This further provides sufficient carbonization space for low-carbon clinker 4. In addition, the carbonization results can also indicate the uniformity of carbonization; the carbonization uniformity is better for conditions above the trend line and worse for conditions below the trend line.

[0084] Comparative Example 1

[0085] A method for establishing the relationship between the carbonization performance and structure of low-carbon clinker is largely the same as in Example 1, except that the water-cement ratio w / c is selected as 0.16 (this water-cement ratio is a relatively good one determined by conventional methods), instead of the optimal water-cement ratio (0.19) determined by the method described in this invention. The molding amount c is 11.2 g. The clinker is dried under natural conditions to different moisture contents: 6.48%, 7.66%, 8.66%, 10.38%, 11.90%, and 13.36%. After carbonization, the compressive strength σ is obtained. c and carbon fixation rate r c As shown in Table 10:

[0086] Table 10 Compressive Strength and Carbon Fixation Rate

[0087]

[0088] The calculated data are shown in Table 11:

[0089] Table 11 Data Calculation Results

[0090]

[0091] Select the first four sets of data from the six sets in Table 11 to establish W. 总 -σ c Trend line, the trend line is σ c =808.52*W 总 -479.89, R 2=0.9514. Compared to Example 1, the failure to use the optimal water-cement ratio resulted in slightly lower molding density, larger defects, lower and less consistent post-carbonization strength, and a worse fit compared to Example 1. From Figure 3 It can also be seen that the trend lines of Comparative Example 1 and Examples 2, 3, and 4 are not as well matched as those of Example 1. This means that Examples 2, 3, and 4 also need to find a water-cement ratio suitable for Comparative Example 1, which is difficult to design and judge.

[0092] If the selected water-cement ratio is higher than the optimal water-cement ratio, some water will be squeezed out, the height of the pressed sample will be unstable, and the sample will stick to the mold or fall off, making it impossible to design.

[0093] Comparative Example 2

[0094] A method for establishing the relationship between the carbonization performance and structure of low-carbon clinker is largely the same as that in Example 4, except that: six sets of data from Table 9 of Example 4 are selected to establish W. 总 -σ c Trend line, the trend line is σ c =534.86*W 总 -272.43, R 2 =0.6314, indicating a poor fit, and it is impossible to effectively construct the relationship between the carbonization performance and structure of low-carbon clinker.

[0095] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A method for establishing the relationship between the carbonization performance and carbonization structure of low-carbon clinker, characterized in that, Includes the following steps: 1) The optimal water-cement ratio w / c and the corresponding molding amount c for low-carbon clinker were determined by compression molding method; 2) According to the determined optimal water-cement ratio w / c and molding amount c, the low-carbon clinker is pressed into a block, and the apparent volume V of the obtained block is recorded 表观 , dried to different moisture contents, and then carbonized and cured, and the compressive strength σ of the obtained carbonized product under different moisture contents is determined c , and the carbon sequestration rate r c , and the volume V of CaCO3 formed after carbonization CaCO3 , the volume V of the remaining low-carbon clinker after carbonization c ; 3) Calculate the volume V of the formed low-carbon clinker based on the parameters determined above. c0 The volume percentage W of CaCO3 formed after carbonization VCaCO3 The volume percentage of low-carbon clinker remaining after carbonization, W Vc The total volume percentage of CaCO3 and residual low-carbon clinker formed after carbonization is W. 总 ; 4) Establish the compressive strength σ after carbonization c The total volume percentage W of CaCO3 formed after carbonation and the remaining cement clinker 总 The stoichiometric relationship between them.

2. The method according to claim 1, characterized in that, The method for determining the optimal water-cement ratio w / c and molding amount c includes: using a compression molding method, pressing low-carbon clinker into molding samples of the same specifications with different water-cement ratios under the same molding pressure conditions; selecting the maximum water-cement ratio that will not be squeezed out as the optimal water-cement ratio, and the mass of low-carbon clinker contained in the sample at this time is the molding amount of the low-carbon clinker.

3. The method according to claim 1, characterized in that, The moisture content mentioned in step 2) is between 0% and 20%.

4. The method according to claim 1, characterized in that, The carbonization curing process uses a CO2 concentration of 15–100%, a temperature of 20–70°C, a humidity of 50–90%, an air pressure of 0.1–0.6 MPa, and a carbonization time of 8–72 hours.

5. The method according to claim 1, characterized in that, The volume V of the molded low-carbon clinker c0 =c / ρ c Where c is the molding amount, in grams; ρ c The density of low-carbon clinker, in g / cm³ 3 .

6. The method according to claim 1, characterized in that, The volume V of CaCO3 formed after carbonization CaCO3 =c*r c *100 / (44*ρ CaCO3 ), where c is the molding amount, in grams; r c To determine the carbon fixation rate, ρ CaCO3 The density of CaCO3 is 2.6–2.8 g / cm³. 3 .

7. The method according to claim 1, characterized in that, The volume V of the remaining low-carbon clinker after carbonization c =V c0 -[c*r c *56 / (44*ρ CaO ]], where c is the molding amount in grams; r c To determine the carbon fixation rate, ρ CaO The density of CaO is 3.25–3.38 g / cm³. 3 .

8. The method according to claim 1, characterized in that, The volume percentage W of CaCO3 formed by carbonization VCaCO3 =V CaCO3 / V 表观 The volume percentage of low-carbon clinker remaining after carbonization, W Vc =V c / V 表观 The total volume percentage W after carbonization 总 =W VCaCO3 +W Vc .

9. The method according to claim 1, characterized in that, Step 4) establishes the relationship between carbonization intensity and the total volume ratio of CaCO3 formed after carbonization and the remaining low-carbon clinker. This relationship is calculated and fitted using data obtained from pressing low-carbon clinker into shape, drying it to different moisture contents, and then carbonizing it. 总 -σ c Trend line.

10. The method according to claim 9, characterized in that, Choose σ c Less than the maximum value and r c Data corresponding to carbonized products with a carbon fixation rate not exceeding 90% of the maximum value.

Images