Solid-waste-based low-carbon cementing material and preparation method thereof

Abstract

The invention relates to the technical field of solid waste resource utilization, in particular to a solid-waste-based low-carbon cementing material and a preparation method thereof.The preparation method comprises the steps that slag powder, fly ash powder and steel slag powder are put into a stirring pot to be stirred, and a dry material is obtained; pouring an exciting agent into the dry material, stirring to obtain cementing material slurry, and collecting viscosity in the process of preparing the cementing material slurry to form a viscosity curve; judging whether the preparation of the cementing material slurry meets a preset standard or not according to the curve similarity of the cementing material slurry; when it is judged that the standard is not reached according to the curve similarity, a processing strategy when the standard is not reached is determined according to the surface defect characterization value, and the processing strategy refers to emergency shutdown and alarm or reduction of the preset pouring speed; and injecting the cementing material slurry meeting the preset standard into a mold for molding, and performing maintenance treatment to obtain the solid waste-based low-carbon cementing material. According to the invention, the preparation efficiency of the solid waste-based low-carbon cementing material is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solid waste resource utilization, and particularly relates to a solid waste-based low-carbon cementitious material and a preparation method thereof. BACKGROUND

[0002] Cementitious materials are a class of materials that can gradually harden from slurry to solid through physical and chemical actions, and can cement sand, stone and other bulk materials into a whole with mechanical strength, and are widely used in engineering fields such as building, municipal administration and transportation.

[0003] In order to reduce carbon emissions of the cementitious material industry, the use of industrial solid waste (such as slag, fly ash, steel slag, etc.) to prepare low-carbon cementitious materials has become a research hotspot. Such solid waste is rich in active components such as silicon and aluminum, and can generate cementitious products through hydration under the action of an activator, which can not only replace traditional cement to reduce carbon emissions, but also realize the resource utilization of solid waste, and alleviate the problems of land occupation and environmental pollution caused by solid waste storage.

[0004] However, the sources of solid waste raw materials are complex, and the composition fluctuates greatly. The reaction process of the solid waste raw materials with the activator is violent and sensitive. Traditional preparation methods mostly rely on fixed proportions and empirical stirring processes, and cannot dynamically adjust according to the real-time state of the reaction process, which can easily cause poor slurry uniformity, poor fluidity, even instantaneous solidification or segregation, etc., resulting in unstable product quality and high waste rate.

[0005] At present, the judgment of the reaction process mostly depends on end-point performance detection (such as testing the strength of the final product) or single parameter monitoring, which cannot be used for adaptive regulation in the production process, and cannot comprehensively and accurately represent the complex reaction state inside the slurry and surface defects (such as agglomeration).

[0006] In the preparation process of the solid waste-based low-carbon cementitious material, a common and difficult technical problem is the agglomeration phenomenon. Agglomeration refers to the fact that powdery raw materials (such as slag, fly ash) cannot form a uniform slurry when mixed with an alkaline activator, but instead locally aggregate into spherical or block-shaped agglomerates of varying sizes. The inside of these agglomerates is often not fully infiltrated by the liquid, and the reaction is incomplete, like a “hard core” mixed into the slurry, which is extremely harmful. First, it seriously damages the homogeneity of the material, significantly reduces and stabilizes the mechanical properties (such as compressive and flexural strength) of the final product. Second, there is a weak interface between the agglomerates and the matrix, which can become a channel for the invasion of harmful media, greatly reducing the impermeability and durability of the material. Third, the solid waste raw materials inside the agglomerates cannot effectively participate in the reaction, causing waste of raw materials. Traditional preparation processes rely on fixed proportions and empirical operations, and cannot monitor and effectively suppress the generation of agglomeration in real time, which is one of the key bottlenecks restricting the quality stability and large-scale application of solid waste-based cementitious materials.

[0007] Chinese patent application publication No. CN117088634A discloses a composite mineral admixture and its preparation method and application. The composite mineral admixture comprises the following components by mass fraction: mineral powder: 30-50 parts; gypsum powder: 1-3 parts; fly ash: 30-50 parts; steel slag: 0-30 parts; activator: 0.01-0.5 parts. The preparation method of the composite mineral admixture comprises the following steps: mixing the mineral powder, the gypsum powder and the activator for grinding, then adding the fly ash and the steel slag ground to different particle size intervals respectively and mixing uniformly to obtain the composite mineral admixture.

[0008] It can be seen that the above technical solution does not consider the real-time viscosity change of the reaction slurry in the mixing and stirring process, which affects the mixing uniformity of the slurry, thereby causing the problem of poor preparation efficiency of the solid waste-based low-carbon cementitious material. SUMMARY

[0009] Therefore, the present application provides a solid waste-based low-carbon cementitious material and its preparation method to overcome the problem in the prior art that the real-time viscosity change of the reaction slurry in the mixing and stirring process is not considered, which affects the mixing uniformity of the slurry, thereby causing the problem of poor preparation efficiency of the solid waste-based low-carbon cementitious material.

[0010] To achieve the above-mentioned purpose, in one aspect, the present application provides a preparation method of a solid waste-based low-carbon cementitious material, comprising: putting slag powder, fly ash powder and steel slag powder into a stirring pot for stirring to obtain dry materials; pouring the activator into the dry materials at a preset pouring rate and stirring at a preset stirring rate, and obtaining a cementitious material slurry when the viscosity of the slurry reaches a preset viscosity, wherein the viscosity of the cementitious material slurry is collected in real time during the preparation of the cementitious material slurry to form a viscosity curve, and the curve similarity of the cementitious material slurry is obtained; determining whether the preparation of the cementitious material slurry meets the preset standard according to the curve similarity of the cementitious material slurry; when the preparation of the cementitious material slurry does not meet the preset standard according to the curve similarity, determining the processing strategy when the preparation of the cementitious material slurry does not meet the preset standard according to the surface defect characterization value of the cementitious material slurry, wherein the processing strategy is emergency shutdown and alarm or reducing the preset pouring rate; injecting the cementitious material slurry meeting the preset standard into a mold for molding and performing curing treatment to obtain a solid waste-based low-carbon cementitious material.

[0011] Further, the granulated blast furnace slag powder is 50-80 parts, the fly ash powder is 15-40 parts, and the steel slag powder is 5-15 parts.

[0012] Further, the activator is prepared by mixing sodium hydroxide solution and sodium silicate solution, wherein the alkali equivalent of the activator accounts for 4-8% of the mass of the dry material in terms of alkali equivalent of sodium oxide, and the molar ratio of silicon dioxide to sodium oxide of the activator is 1.0-1.5.

[0013] Further, the process of determining whether the preparation of the cementitious material slurry meets the preset standard according to the curve similarity of the cementitious material slurry comprises: comparing the curve similarity with a first preset curve similarity and a second preset curve similarity respectively; if the curve similarity is less than the first preset curve similarity, it is determined that the preparation of the cementitious material slurry does not meet the preset standard, and a processing strategy is determined according to the surface defect representation value of the cementitious material slurry when the preparation of the cementitious material slurry does not meet the preset standard; if the curve similarity is greater than or equal to the first preset curve similarity and less than the second preset curve similarity, it is determined that the preparation of the cementitious material slurry meets the preset standard, and whether the preparation of the cementitious material slurry meets the preset standard is determined again according to the temperature standard deviation of the slurry surface; if the curve similarity is greater than or equal to the second preset curve similarity, it is determined that the preparation of the cementitious material slurry meets the preset standard.

[0014] Further, the process of obtaining the curve similarity of the cementitious material slurry comprises: During the preparation of the cementitious material slurry, the viscosity of the cementitious material slurry is collected in real time at a preset time interval to generate a viscosity curve of viscosity changing with time; the shape matching calculation of the viscosity curve and a preset standard viscosity curve is performed by using a dynamic time warping algorithm to obtain the curve similarity of the cementitious material slurry, wherein the preset standard viscosity curve is a viscosity curve of viscosity changing with time of a cementitious material slurry meeting the preset preparation standard under the same preparation condition.

[0015] Further, according to the comparison result that the temperature standard deviation of the slurry surface is greater than the preset temperature standard deviation, the preset stirring rate is increased according to the difference between the preset temperature standard deviation and the temperature standard deviation; The temperature standard deviation of the slurry surface is the standard deviation of the temperature of a plurality of detection points on the surface of the cementitious material slurry.

[0016] Further, there are a plurality of rate adjustment modes for the increase of the preset stirring rate, and each rate adjustment mode has a different increase amplitude of the preset stirring rate.

[0017] Further, the process of determining the treatment strategy when the preparation of the cementitious material slurry does not meet the preset standard according to the surface defect characterization value of the cementitious material slurry comprises: comparing the surface defect characterization value with a preset surface defect threshold value; if the surface defect characterization value is less than the preset surface defect threshold value, emergency shutdown and alarm; if the surface defect characterization value is greater than or equal to the preset surface defect threshold value, reducing the preset pouring rate according to the difference between the surface defect characterization value and the preset surface defect threshold value.

[0018] Further, the process of obtaining the surface defect characterization value of the cementitious material slurry comprises: collecting a surface image of the cementitious material slurry; converting the surface image into a gray-scale image, calculating the standard deviation of the gray-scale values of all pixel points in the gray-scale image, and recording it as the surface defect characterization value of the cementitious material slurry.

[0019] On the other hand, the present application provides a solid waste-based low-carbon cementitious material, which is prepared by the above method and has a 28d dry shrinkage rate of less than or equal to 0.035%.

[0020] Compared with the prior art, the present application has the beneficial effects that the present application constructs a closed-loop process of multi-parameter cooperative detection, setting of hierarchical judgment, and quantitative adjustment of preparation parameters through real-time viscosity monitoring (dynamic time warping algorithm comparison), temperature standard deviation detection, and surface defect quantitative characterization, ensures that the reaction course of each batch of products can accurately reproduce the optimal process path, changes the traditional operation relying on fixed formula and manual experience into intelligent control based on multi-source information perception, collects the viscosity of the slurry in real time and forms a curve, calculates the similarity, dynamically tracks the whole process of the hydration reaction of the slurry, instead of relying on only the viscosity value at a single time point, can timely find the problem of abnormal viscosity of the slurry, avoids the waste of raw materials caused by the out-of-control state of the slurry in the subsequent forming process; when the curve similarity does not meet the standard, a differentiated adaptive treatment strategy of emergency shutdown alarm or reducing the pouring rate of the activator is formulated according to the surface defect characterization value, which can not only stop loss in time when the abnormality is serious, but also ensure continuous production by parameter adjustment when the abnormality is slight, reducing production interruption; at the same time, the overall process uses solid waste as the main raw material, greatly reduces the amount of traditional cement clinker, realizes the resource utilization of solid waste and reduces carbon emissions, thereby improving the preparation efficiency of the solid waste-based low-carbon cementitious material.

[0021] Further, the present application divides the quality judgment into three levels of unqualified, critical qualified and qualified by setting two preset similarity thresholds, improves the fineness and accuracy of the judgment; for the critical state, the temperature standard deviation is introduced for secondary verification judgment, avoiding the misjudgment of a single parameter, further optimizing the quality control logic; for the comparison result of high similarity, the slurry is directly judged as qualified, avoiding excessive detection; the three-level judgment logic takes into account strict quality control and efficient production, reduces misjudgment and omission, thereby improving the reliability of the judgment.

[0022] Further, the present application obtains the curve similarity by a specific method, collects viscosity in real time according to a preset time interval, can obtain continuous viscosity data of the whole process of the slurry hydration reaction instead of discrete data at a single time point, can fully reflect the change of the slurry state, avoids misjudgment caused by accidental single-point data, adopts the dynamic time warping algorithm for curve shape matching, only pays attention to the curve shape similarity instead of the absolute time node, reduces misjudgment, and thereby improves the reliability of the similarity calculation.

[0023] Further, the present application sets the slurry surface temperature standard deviation, which can directly reflect the mixing uniformity of the slurry, makes up for the monitoring blind area of uniform viscosity but uneven mixing, avoids the risk of temperature stress cracking in the subsequent hardening stage in advance, and thereby improves the intelligent level of detection.

[0024] Further, the present application compares the surface defect characterization value with the preset surface defect threshold value, and executes different processing strategies according to the comparison result, intelligently distinguishes the type of fault, if the value is less than the preset threshold value, it indicates that the surface of the slurry is too uniform and lacks texture change, which usually means that serious and large-area clumping occurs, but because the surface of the lump is smooth and huge, it covers the entire field of view, for serious defects, emergency shutdown and alarm; if the value is greater than or equal to the preset threshold value, it indicates that the surface of the slurry is rough and the texture change is large, which means that there is local and dispersed slight clumping, for slight defects, the processing strategy of reducing the pouring rate is adopted, which reduces the local alkali concentration and reaction rate, provides time for the stirrer to disperse the small lumps formed and makes the reaction more uniform, thereby reducing the dependence on artificial experience. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 It is a flowchart of the preparation method of the solid waste-based low-carbon cementitious material of the embodiment of the present application; Figure 2 It is a flowchart of the present application for judging whether the preparation of the cementitious material slurry meets the preset standard according to the curve similarity of the cementitious material slurry; Figure 3 It is a flowchart of the present application for secondary judging whether the preparation of the cementitious material slurry meets the preset standard; Figure 4A flow chart for determining a processing strategy when the preparation of the cementitious material slurry does not meet the preset standard for the embodiment of the present application. DETAILED DESCRIPTION

[0026] In order to make the objects and advantages of the present application clearer, the present application will be further described below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application.

[0027] The preferred embodiments of the present application will be described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present application and are not used to limit the protection scope of the present application.

[0028] It should be pointed out that the data in the present embodiment are obtained by comprehensive analysis and evaluation of historical detection data and corresponding historical detection results of the present application in the past three months before the present detection. Those skilled in the art can understand that the determination method of the present application for a single parameter can be to select the value with the highest proportion as the preset standard parameter according to the data distribution, to use weighted summation to obtain the value as the preset standard parameter, to substitute each historical data into a specific formula and to obtain the value as the preset standard parameter using the formula, or other selection methods, as long as the present application can clearly define different specific situations in the single determination process through the obtained value.

[0029] Please refer to Figure 1 , Figure 2 , Figure 3 and Figure 4 , which are respectively a flow chart of a preparation method of a solid waste-based low-carbon cementitious material according to an embodiment of the present application; a flow chart of determining whether the preparation of a cementitious material slurry meets a preset standard according to the curve similarity of the cementitious material slurry according to an embodiment of the present application; a flow chart of twice determining whether the preparation of a cementitious material slurry meets a preset standard according to an embodiment of the present application; and a flow chart of determining a processing strategy when the preparation of a cementitious material slurry does not meet a preset standard according to an embodiment of the present application.

[0030] In one aspect, an embodiment of the present application provides a preparation method of a solid waste-based low-carbon cementitious material, comprising: Step S1, putting slag powder, fly ash powder and steel slag powder into a stirring pot for stirring to obtain dry materials; Step S2, pouring an activator into the stirring pot containing the dry materials at a preset pouring rate of 20 mL / min and stirring at a preset stirring rate of 100 rpm, and when the viscosity of the slurry reaches a preset viscosity of 2 Pa·s, a cementitious material slurry is obtained, wherein in the process of preparing the cementitious material slurry, the viscosity of the cementitious material slurry is collected in real time to form a viscosity curve, and the curve similarity of the cementitious material slurry is obtained. Step S3, determining whether the preparation of the cementitious material slurry meets the preset standard according to the curve similarity of the cementitious material slurry; Step S4, when the preparation of the cementitious material slurry is determined not to meet the preset standard according to the curve similarity, determining a processing strategy when the preparation of the cementitious material slurry does not meet the preset standard according to the surface defect characterization value of the cementitious material slurry, wherein the processing strategy is emergency shutdown and alarm or reducing the preset pouring rate; Step S5, injecting the cementitious material slurry meeting the preset standard into a 40mm*40mm*160mm mold for molding, covering a preservative film after vibration molding, demolding after 24h curing at 20℃, and then placing in a standard curing box for curing until 28 days to obtain a solid waste-based low-carbon cementitious material.

[0031] It should be pointed out that the data in the present embodiment are results obtained through the method of the present application through preliminary experimental verification before the present detection, and each preset value can be adjusted according to specific use conditions, as long as the method of the present application can clearly define different specific conditions in the single determination process by obtaining numerical values. The preset values set in the present embodiment are obtained according to preliminary experiments, and each correction coefficient is also selected through experimental verification.

[0032] Specifically, the slag, fly ash and steel slag are dried respectively, and the water content is controlled within 10wt%, the steel slag is coarsely crushed using a jaw crusher, and the fly ash, coarsely crushed steel slag and slag are ground using a planetary ball mill, and then sieved using a 300 mesh sieve to obtain slag powder, fly ash powder and steel slag powder respectively.

[0033] Specifically, the granulated blast furnace slag powder is 50-80 parts, the fly ash powder is 15-40 parts, and the steel slag powder is 5-15 parts.

[0034] In the present embodiment, the granulated blast furnace slag powder is selected as 65 parts, the fly ash powder is selected as 28 parts, and the steel slag powder is selected as 10 parts.

[0035] Specifically, the activator is made by mixing sodium hydroxide solution and sodium silicate solution, wherein the alkali equivalent of the activator accounts for 4%-8% of the mass of the dry material in terms of sodium oxide equivalent, and the mass ratio in the present embodiment is selected as 6%, and the molar ratio of silicon dioxide to sodium oxide of the activator is 1.0-1.5, and the molar ratio in the present embodiment is selected as 1.2.

[0036] Specifically, the process of determining whether the preparation of the cementitious material slurry meets the preset standard according to the curve similarity of the cementitious material slurry includes: The curve similarity is compared with a first preset curve similarity and a second preset curve similarity respectively. If the curve similarity is less than the first preset curve similarity 0.65, it is determined that the preparation of the cementitious material slurry does not meet the preset standard, and a processing strategy when the preparation of the cementitious material slurry does not meet the preset standard is determined according to the surface defect characterization value of the cementitious material slurry. If the curve similarity is greater than or equal to the first preset curve similarity and less than the second preset curve similarity 0.90, it is determined that the preparation of the cementitious material slurry meets the preset standard, and whether the preparation of the cementitious material slurry meets the preset standard is determined again according to the temperature standard deviation of the surface of the slurry. If the curve similarity is greater than or equal to the second preset curve similarity, it is determined that the preparation of the cementitious material slurry meets the preset standard.

[0037] In this embodiment, the value range of the first preset curve similarity is (0.55, 0.70), and the value range of the second preset curve similarity is (0.80, 0.95). In this embodiment, the value of the first preset curve similarity is 0.65, and the value of the second preset curve similarity is 0.90.

[0038] Specifically, the curve similarity calculated by the dynamic time warping algorithm represents the degree of coincidence between the change trend of the real-time slurry viscosity with time and the viscosity trend of the standard qualified slurry. The more coincident the trends are (the higher the similarity is), the more stable the hydration reaction process and the rheological properties of the slurry are.

[0039] Specifically, the process of obtaining the curve similarity of the cementitious material slurry includes: During the preparation of the cementitious material slurry, a viscometer is used to collect the viscosity of the cementitious material slurry in real time at a preset time interval of 10 s to generate a viscosity curve of viscosity change with time. A dynamic time warping algorithm is used to perform morphological matching calculation on the viscosity curve and a preset standard viscosity curve to obtain the curve similarity of the cementitious material slurry, wherein the preset standard viscosity curve is a viscosity curve of viscosity change with time of a cementitious material slurry that meets the preset preparation standard under the same preparation conditions.

[0040] Specifically, whether the preparation of the cementitious material slurry meets the preset standard is determined again according to the temperature standard deviation of the surface of the slurry, wherein If the temperature standard deviation of the surface of the slurry is less than a preset temperature standard deviation 2.5℃, it is determined that the preparation of the cementitious material slurry meets the preset standard. If the temperature standard deviation of the slurry surface is greater than or equal to the preset temperature standard deviation, it is determined that the preparation of the cementitious material slurry does not meet the preset standard, and the preset stirring rate is increased according to the difference between the preset temperature standard deviation and the temperature standard deviation; The temperature standard deviation of the slurry surface is the standard deviation of the temperature of several detection points on the surface of the cementitious material slurry.

[0041] Specifically, the temperature standard deviation reflects the uniformity of slurry mixing. The reaction should proceed uniformly, and the temperature rise rate of each part of the slurry is consistent. The surface temperature field is uniform, and the calculated temperature standard deviation value is smaller at this time. On the contrary, the temperature rise rate of each part of the slurry is inconsistent, indicating that the slurry surface temperature distribution is uneven, and the local aggregation of the activator caused by uneven stirring.

[0042] In this embodiment, the preset temperature standard deviation is 2.5℃, but the above value is not limited thereto, and the skilled person in the art can also adjust the value according to actual needs.

[0043] In this embodiment, 10 temperature detection points are uniformly arranged on the surface of the slurry, and the temperature of each point is collected by an infrared thermal imager to calculate the temperature standard deviation.

[0044] Specifically, a plurality of rate adjustment modes are provided for the increase of the preset stirring rate, wherein, If the temperature deviation value is less than the first preset temperature deviation value 0.7℃, the preset stirring rate is increased to the corresponding value by using the first adjustment coefficient 1.02; If the temperature deviation value is greater than or equal to the first preset temperature deviation value and less than the second preset temperature deviation value 1.4℃, the preset stirring rate is increased to the corresponding value by using the second adjustment coefficient 1.04; If the temperature deviation value is greater than or equal to the second preset temperature deviation value, the preset stirring rate is increased to the corresponding value by using the third adjustment coefficient 1.06; The temperature deviation value is the difference between the preset temperature standard deviation and the temperature standard deviation.

[0045] Specifically, the process of determining the processing strategy when the preparation of the cementitious material slurry does not meet the preset standard according to the surface defect representation value of the cementitious material slurry includes: The surface defect representation value is compared with a preset surface defect threshold value; If the surface defect representation value is less than the preset surface defect threshold value 35, the machine is stopped urgently and an alarm is given; If the surface defect representation value is greater than or equal to the preset surface defect threshold value, the preset pouring rate is reduced according to the difference between the surface defect representation value and the preset surface defect threshold value.

[0046] Specifically, the surface defect characterization value of the cementitious material slurry is obtained by the following process: acquiring a surface image of the cementitious material slurry by an industrial camera; converting the RGB color surface image into a grayscale image (pixel range 0-255) by OpenCV image processing software, calculating the standard deviation of the grayscale values of all pixel points in the grayscale image, and recording the standard deviation as the surface defect characterization value of the cementitious material slurry.

[0047] In this embodiment, the preset surface defect threshold value is 35, but the above-mentioned value is not limited thereto, and the value can be adjusted according to actual needs by those skilled in the art.

[0048] Specifically, the surface defect characterization value (standard deviation of grayscale value) reflects the micro-uniformity of the surface of the slurry. When the characterization value is less than the threshold value, it indicates that the surface is uniform, but under the premise that the preparation of the slurry is not up to standard according to the curve similarity degree determination, it indicates that there are systemic problems such as serious lack of raw material activity and failure of the chemical properties of the activator, and the system immediately stops and alarms. When the characterization value is greater than or equal to the threshold value, it indicates that the surface is rough and there are local micro-agglomerates. The system promotes the stirring by reducing the pouring rate of the activator in the form of regulation to disperse the agglomerates.

[0049] On the other hand, the embodiment of the present application provides a solid waste-based low-carbon cementitious material, which is prepared by the above-mentioned method, and has a 28d dry shrinkage rate of less than or equal to 0.035%.

[0050] The embodiment is a solid waste-based low-carbon cementitious material prepared according to the above-mentioned solid waste-based low-carbon cementitious material. Comparative Example 1

[0051] Compared with the example group, no detection adjustment is used, and traditional fixed parameters are used for preparation. 65 parts of slag powder, 28 parts of fly ash powder and 10 parts of steel slag powder are dry mixed, then the activator is poured at a rate of 20 mL / min, and the stirring rate is kept constant at 100 rpm during the whole stirring process. The stirring time is fixed at 10 minutes, and then the slurry is injected into the mold for curing. Comparative Example 2

[0052] Compared with the example group, only the viscosity is monitored for preparation. 65 parts of slag powder, 28 parts of fly ash powder and 10 parts of steel slag powder are dry mixed, then the activator is poured at a rate of 20 mL / min, the stirring rate is kept at 100 rpm, the slurry viscosity is monitored by an online viscometer, and the stirring is stopped only when the slurry viscosity reaches 2 Pa·s.

[0053] Table 1 Performance test results of solid waste-based low-carbon cementitious materials prepared in the experimental examples, comparative example 1 and comparative example 2 ; As can be seen from Table 1, the gelled material prepared in the embodiment of the present application is superior to Comparative Example 1 and Comparative Example 2 in terms of 28d dry shrinkage, 28d compressive strength and whether the slurry is clustered, which indicates that the present application effectively inhibits the defects caused by internal uneven reaction and stress concentration of the slurry, guarantees the fullness and uniformity of the hydration reaction, and thus forms a more compact and solid solid-waste-based low-carbon gelled material.

[0054] So far, the technical solutions of the present application have been described in combination with the preferred embodiments shown in the drawings, but it is easy for those skilled in the art to understand that the protection scope of the present application is obviously not limited to these specific embodiments. Those skilled in the art can make equivalent changes or replacements to the related technical features without departing from the principles of the present application, and the technical solutions after the changes or replacements will fall within the protection scope of the present application.

[0055] The above description is only the preferred embodiments of the present application and is not intended to limit the present application; for those skilled in the art, the present application can have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing a solid waste-based low-carbon cementitious material, characterized in that, include: Slag powder, fly ash powder and steel slag powder are put into a mixing pot and stirred to obtain dry material; The activator is poured into the dry material at a preset pouring rate and stirred at a preset stirring rate. When the viscosity of the slurry reaches the preset viscosity, a cementitious material slurry is obtained. During the preparation of the cementitious material slurry, the viscosity of the cementitious material slurry is collected in real time to form a viscosity curve, and the curve similarity of the cementitious material slurry is obtained. The similarity of the curves of the cementitious material slurry is used to determine whether the preparation of the cementitious material slurry meets the preset standard; When the preparation of the cementitious material slurry does not meet the preset standard based on the curve similarity, the processing strategy for the preparation of the cementitious material slurry does not meet the preset standard is determined based on the surface defect characterization value of the cementitious material slurry. The processing strategy is to shut down the machine and issue an alarm or reduce the preset pouring rate. The cementitious material slurry that meets the preset standards is injected into a mold to form a solid waste-based low-carbon cementitious material.

2. The method for preparing solid waste-based low-carbon cementitious material according to claim 1, characterized in that, Granulated blast furnace slag powder 50-80 parts, fly ash powder 15-40 parts, steel slag powder 5-15 parts.

3. The method for preparing solid waste-based low-carbon cementitious materials according to claim 1, characterized in that, The activator is prepared by mixing sodium hydroxide solution and sodium silicate solution, wherein the alkali equivalent of the activator, calculated as sodium oxide, accounts for 4%-8% of the mass of the dry material, and the molar ratio of silicon dioxide to sodium oxide in the activator is 1.0-1.

5.

4. The method for preparing solid waste-based low-carbon cementitious material according to claim 1, characterized in that, The process of determining whether the preparation of the cementitious material slurry meets the preset standard based on the curve similarity of the cementitious material slurry includes: The curve similarity is compared with the first preset curve similarity and the second preset curve similarity respectively; If the curve similarity is less than the first preset curve similarity, it is determined that the preparation of the cementitious material slurry does not meet the preset standard, and the processing strategy when the preparation of the cementitious material slurry does not meet the preset standard is determined according to the surface defect characterization value of the cementitious material slurry. If the curve similarity is greater than or equal to the first preset curve similarity and less than the second preset curve similarity, then the preparation of the cementitious material slurry is determined to meet the preset standard, and the preparation of the cementitious material slurry is further determined based on the temperature standard deviation of the slurry surface. If the curve similarity is greater than or equal to the second preset curve similarity, then the preparation of the cementitious material slurry is determined to meet the preset standard.

5. The method for preparing solid waste-based low-carbon cementitious material according to claim 4, characterized in that, The process of obtaining the curve similarity of the cementitious material slurry includes: During the preparation of the cementitious material slurry, the viscosity of the cementitious material slurry is collected in real time at preset time intervals to generate a viscosity curve of viscosity changing over time. A dynamic time warping algorithm is used to perform morphological matching calculations on the viscosity curve and the preset standard viscosity curve to obtain the curve similarity of the cementitious material slurry. The preset standard viscosity curve is the viscosity curve of the cementitious material slurry that meets the preset preparation standard under the same preparation conditions as the viscosity changes over time.

6. The method for preparing solid waste-based low-carbon cementitious material according to claim 5, characterized in that, If the preparation of the cementitious material slurry does not meet the preset standard, the preset stirring rate is increased based on the difference between the preset temperature standard deviation and the temperature standard deviation when the comparison result of the temperature standard deviation of the slurry surface is greater than the preset temperature standard deviation. The standard deviation of the temperature on the surface of the slurry is the standard deviation of the temperature at several detection points on the surface of the cementitious material slurry.

7. The method for preparing solid waste-based low-carbon cementitious material according to claim 6, characterized in that, Several speed adjustment methods are provided for increasing the preset stirring rate, and each speed adjustment method increases the preset stirring rate by a different amount.

8. The method for preparing solid waste-based low-carbon cementitious material according to claim 7, characterized in that, The process of determining the handling strategy when the preparation of the cementitious material slurry does not meet the preset standard based on the surface defect characterization value of the cementitious material slurry includes: The surface defect characterization value is compared with a preset surface defect threshold. If the surface defect characterization value is less than the preset surface defect threshold, an emergency shutdown and alarm will be triggered. If the surface defect characterization value is greater than or equal to the preset surface defect threshold, the preset pouring rate is reduced based on the difference between the surface defect characterization value and the preset surface defect threshold.

9. The method for preparing solid waste-based low-carbon cementitious material according to claim 8, characterized in that, The process of obtaining the surface defect characterization values ​​of the cementitious material slurry includes: Acquire surface images of the cementitious material slurry; The surface image is converted into a grayscale image, and the standard deviation of the grayscale values ​​of all pixels in the grayscale image is calculated and recorded as the surface defect characterization value of the cementitious slurry.

10. A solid waste-based low-carbon cementitious material, characterized in that, The solid waste-based low-carbon cementitious material is prepared by any one of the preparation methods according to claims 1-9, and its 28-day drying shrinkage rate is less than or equal to 0.035%.

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