Method for constructing hydration kinetic model of cemented filling body under temperature effect

Abstract

The invention discloses a method for constructing a hydration kinetic model of a cemented filling body under a temperature effect. The method comprises the following steps: 1, carrying out an indoor hydration heat experiment on the cemented filling body, selecting a cementing material, tailings and water as preparation materials of the cemented filling body, and measuring hydration heat release and heat release rate of the cemented filling body; 2, verifying a hydration heat experiment result by adopting a boundary nucleation-growth model, and calculating a nucleation rate Iv and a normal growth rate G of a hydration product at different temperatures; 3, changing a constant normal growth rate into a variable normal growth rate, and introducing a nucleation rate influence factor I0 and a nucleation influence factor M0 to carry out boundary nucleation-growth model correction so as to obtain a corrected hydration kinetic model; and 4, verifying the accuracy of the corrected boundary nucleation-growth model. The method can accurately reveal macroscopic and microscopic mechanisms and association in the hydration reaction process, and has the characteristics of accurate hydration characteristic analysis and high universality.

Description

Technical Field

[0001] The invention relates to the field of computational material science and technology, and in particular to a method for constructing a hydration kinetic model of a cemented filling body under temperature effects. Background Art

[0002] In response to the challenges faced by the modernization of deep resource mining, the backfill mining method has attracted much attention in deep mining due to its advantages such as low loss, low cost, utilization of waste, and effective control of ground pressure. In the backfill mining method, the cemented backfill body is a key part or even a permanent component in the underground stope. Its performance is crucial to controlling the ground pressure in the stope during the mining process and maintaining the long-term stability of the underground stope structure. The strength of the cemented backfill body mainly depends on the hydration reaction of the cementitious material to produce hydration products such as gelled hydrated calcium silicate and calcium hydroxide, which then quickly solidify into a consolidated body with a certain strength. It is well known that temperature is highly sensitive to hydration reactions, and it is very likely to have a direct impact on the characteristics of the backfill body in the deep environment.

[0003] Cemented filling body is a kind of complex internal porous artificial composite material. In its internal structure, the hydration products of cementitious materials and tailings are unevenly distributed, which makes the internal structure show obvious uneven characteristics and the microstructure is quite different. Changes in temperature will have a significant impact on the hydration reaction rate, hydration products and internal pore structure of the filling body. In order to ensure the safe application of the filling method in deep mining, it is necessary to focus on the hydration mechanism of cemented filling body under different curing temperatures. The study of hydration kinetics mainly describes the hydration reaction rate. Based on the kinetics study, the macroscopic and microscopic mechanisms and correlations in the hydration reaction process can be accurately revealed, and the internal and external factors in the hydration reaction process can be dynamically explained. Therefore, studying the hydration kinetics characteristics of cemented filling body can essentially explain the formation of the macroscopic properties of the filling body and the damage and destruction mechanism of the internal structure.

[0004] The existing technology mainly focuses on the hydration kinetics analysis of cementitious materials, composite cementitious materials, etc. For example, the Chinese patent with publication number CN110853107A proposes a method for numerically calculating the hydration kinetics of alkali-activated slag materials based on color changes; the existing defects are that the test method is relatively complicated, and the theoretical explanation of hydration analysis using the Krustulovic-Dabic reaction kinetics model is relatively insufficient.

[0005] The Chinese patent with publication number CN109903819A proposes a method for analyzing the hydration dynamic parameters of silicate cement composite cementitious materials; the existing defects are that it cannot accurately express the correlation characteristics between microscopic and macroscopic phenomena in the hydration reaction process, and when the hydration heat release is low, the calculation error using this patent is large.

[0006] Different from the hydration reaction of cementitious materials, the cementitious filling body has a large proportion of tailings inside, which generally accounts for more than 80% of the solid mass. However, tailings are inert materials and do not participate in the hydration reaction. The distribution of cementitious materials in the inert materials makes the hydration process different. Therefore, the hydration analysis method of cementitious materials is no longer applicable.

[0007] Existing research lacks analysis on the hydration dynamics of cemented filling bodies. Summary of the invention

[0008] In order to overcome the defects of the above-mentioned prior art, the purpose of the present invention is to provide a method for constructing a hydration kinetic model of cemented filling under temperature effect, which can accurately reveal the macroscopic and microscopic mechanisms and correlations in the hydration reaction process, and has the characteristics of accurate hydration characteristic analysis and strong universality.

[0009] In order to achieve the above object, the technical solution adopted by the present invention is: A method for constructing a hydration dynamics model of a cemented filling body under temperature effect comprises the following steps; Step 1: Select cementitious materials, tailings and water as materials for preparing cemented filling body, conduct indoor hydration heat experiment of cemented filling body, and measure the hydration heat release and heat release rate of cemented filling body under the condition of 20-60℃; Step 2: Use the boundary nucleation-growth model to verify the hydration heat experimental results and calculate the nucleation rate I of the hydration product at different temperatures v , constant normal growth rate G value; Step 3: Change the constant normal growth rate to a variable normal growth rate, introduce the nucleation rate influencing factor I0 and the nucleation effect influencing factor M0 to correct the boundary nucleation-growth model, and obtain the corrected hydration kinetic model; Step 4: Calculate the normal growth rate and critical length of the hydration product nucleus of the modified hydration kinetic model through the control variable method, and verify the accuracy of the modified boundary nucleation-growth model.

[0010] Step 1: Indoor hydration heat experiment is carried out by isothermal calorimetry, and the experimental instrument is a TAM Air eight-channel isothermal calorimeter; The cementitious material selected is 42.5R ordinary Portland cement; the tailings are the waste after mineral processing, and the chemical components in the waste are mainly silicon dioxide and aluminum oxide, with the mass percentage of silicon dioxide accounting for 71.16%, the mass percentage of aluminum oxide accounting for 13.40%, and the rest being a small amount of compounds such as potassium oxide (the mass percentage is less than 5%); the waste is dried and ground to obtain the whole tailings used in the experiment, and the size of the whole tailings is less than 1 mm; the water is tap water in the laboratory.

[0011] In the step 1, the mass ratio of the cementitious material to the tailings is 1:6, and the slurry material is prepared at a concentration of 70% of the solid mass to total mass ratio. The solid mass is the cementitious material and the tailings, and the total mass is the cementitious material, the tailings and the water. After stirring evenly, the slurry is loaded into a 20 mL centrifuge tube for testing, and the test time is controlled to be 7d. In order to avoid the phenomenon of slow heating of the slurry during the initial measurement process, the material and the water are heated before stirring to ensure that the material temperature is consistent with the curing temperature.

[0012] When verifying the results of the hydration heat experiment in step 2, crystal nuclei are generated on the surface of solid particles formed by 42.5R ordinary Portland cement and whole tailings; When the hydration reaction occurs, the generated crystal nuclei grow and diffuse outward in the form of an ellipsoid based on the solid particles. When adjacent crystal nuclei grow to contact each other, the contact positions will stop growing further.

[0013] In the boundary nucleation-growth model, the nucleation rate of the crystal nucleus is set to a constant I v ; The number of crystal nuclei per unit volume is N v ; The radial growth rate of the crystal nucleus is G; Considering that the crystal nucleus is an ellipsoidal growth mode, the ratio of the tangential growth rate to the normal growth rate is set to g; Since the adjacent nuclei will come into contact during the growth process, the overlapping area is calculated twice in the calculation of the total area. Therefore, the percentage of the total area increment reduced by the overlapping of adjacent nuclei is set to be equal to the total area fraction of the actual generated nuclei. The actual area of ​​a single nucleus is: (1) Among them, S is the actual crystal nucleus area; x is the distance from the nucleation surface; t is the specific time of crystal nucleus growth; integrating the actual crystal nucleus area can obtain the nominal volume fraction of the ellipsoid in the entire space: (2) Among them, V e is the nominal volume fraction of the crystal nucleus; SA V is the total nucleation surface area per unit volume; to simplify the calculation formula, let x = uGt, then dx = Gtdu; u is another variable set; Similarly, since adjacent nuclei will come into contact during the growth process, the volume of the overlapping area is calculated twice during the calculation process. Therefore, the percentage of the total volume increment reduced by the overlap of adjacent nuclei is set to be equal to the total volume fraction of the nuclei actually generated. By integrating the nominal volume fraction, the actual total volume fraction of the nucleus growth process is obtained as: (3).

[0014] Step 2 introduces the proportionality coefficient A, which is a constant value for quantifying the volume fraction and the hydration heat release. V is the actual total volume fraction of the crystal nucleus growth process, and the quantitative characterization relationship between the crystal nucleus volume fraction and the hydration heat release Q is achieved as follows: (4) Step 2: Use nonlinear curve fitting software 1stopt5.0 to calculate the proportional coefficient A and nucleation rate I in the boundary nucleation-growth model. v , the fitting acquisition of the normal growth rate G parameter, the model theoretical curve is obtained by parameter calculation, and the experimental curve is compared with the model theoretical curve; The nucleation rate I obtained by analyzing the fitting results v , the relationship between the normal growth rate G and the curing temperature, and the curing temperature is used to quantitatively characterize the nucleation rate and the normal growth rate.

[0015] In step 3, the nucleation rate influencing factor I0 is introduced to optimize the nucleation rate. The addition of the nucleation rate influencing factor corrects the nucleation rate in the hydration process to a fixed value close to the actual nucleation rate. First, the nucleation rate is optimized, and the nucleation rate of the cemented filling body in the growth space is optimized to: (5) Among them, MI v is the nucleation rate of the corrected cemented filling body; I v Nucleation rate of cemented filling at different temperatures.

[0016] In step 3, the growth rate is analyzed, and the normal growth rate G of the cemented filling body crystal nucleus and the hydration time are defined as G( ); the normal length a of the crystal nucleus from time x to time t is: (6) According to the nucleation rate constant MI v1 , the actual total area of ​​the crystal nucleus S1 is obtained by integration: (7) Among them, S1 is the actual crystal nucleus area after correction; integrating the actual crystal nucleus area, the nominal volume fraction of the ellipsoid in the entire space is obtained as: (8) Among them, V1 e is the nominal volume fraction after correction of the crystal nucleus; SA V1 is the total nucleation surface area of ​​the cemented filling body within a unit volume. Due to the nucleation effect of tailings in the cemented filling body, the nucleation effect factor is introduced to optimize the total nucleation surface area of ​​the cemented filling body within a unit volume. The calculation formula is: (9) Among them, S t is the specific surface area of ​​tailings; f t is the ratio of tailings to solid mass; M0 is the influencing factor of nucleation.

[0017] Step 3: The actual total volume fraction of the total nucleation surface area of ​​the cemented filling body within the unit volume space in its growth space is: (10) The proportional coefficient A1 is introduced, the hydration heat data within 1 h are eliminated, and the parameter B1 is added to control the initial heat release. Finally, the modified boundary nucleation-growth model, that is, the hydration kinetic model is obtained: (11).

[0018] Step 4: The modified hydration kinetic model contains five parameters: nucleation rate influencing factor I0, nucleation effect influencing factor M0, normal growth rate G, proportionality coefficient A and parameter B. Since there are many variables to be calculated and the growth rate is a variable, the modified boundary nucleation-growth model calculation is considered based on the results obtained by the boundary nucleation-growth model. The initial nucleation rate is calculated according to the boundary nucleation-growth model analysis. Subsequently, the corresponding values ​​of the normal growth rate and the hydration time are inversely calculated based on the initial nucleation rate, and then brought into the modified boundary nucleation-growth model to obtain the values ​​of the remaining parameters. Based on the modified boundary nucleation-growth model, the normal growth rate G is calculated at different curing temperatures, and then the critical length Gt of the crystal nucleus is determined; The model calculation results of the heat release and heat release rate of the cemented filling body under different temperature conditions are compared with the measured results.

[0019] Beneficial effects of the present invention: 1) Considering the dilution, dissolution and nucleation of tailings in cemented filling, the constant growth rate is changed to a variable growth rate, and a hydration kinetic model of cemented filling under temperature effect is constructed, which has higher accuracy than the traditional model; 2) Based on the hydration kinetics research, the macroscopic and microscopic mechanisms in the hydration reaction process are related. The growth rate of the hydration reaction of a single crystal nucleus and the nucleation rate reflect the overall hydration heat release of the macroscopic cemented filling body, and the internal factors (growth rate) and external factors (heat release) in the hydration reaction process are dynamically explained; 3) Accurately explain the changing characteristics of the hydration reaction of cemented filling with the curing temperature, and realize the quantitative characterization of the temperature effect of cemented filling. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1A method flow chart provided for a specific embodiment of the present invention.

[0021] Figure 2 It is the cumulative heat release curve and heat release rate curve of the cemented filling body at different temperatures of the present invention.

[0022] Figure 3 This is the calculation model for the growth of the ellipsoidal crystal nucleus of the hydration product of the present invention.

[0023] Figure 4 It is a schematic diagram of the normal growth rate and length of the crystal nucleus at 20°C of the present invention.

[0024] Figure 5 It is a schematic diagram of the normal growth rate and length of the crystal nucleus at 30°C of the present invention.

[0025] Figure 6 It is a schematic diagram of the normal growth rate and length of the crystal nucleus at 40°C of the present invention.

[0026] Figure 7 It is a schematic diagram of the normal growth rate and length of the crystal nucleus at 50°C of the present invention.

[0027] Figure 8 It is a schematic diagram of the normal growth rate and length of the crystal nucleus at 60° C. of the present invention.

[0028] Fig. 9 It is a schematic diagram of the kinetic model fitting analysis at 20°C of the present invention.

[0029] Fig.10 It is a schematic diagram of the kinetic model fitting analysis at 30°C of the present invention.

[0030] Fig.11 It is a schematic diagram of the kinetic model fitting analysis at 40°C of the present invention.

[0031] Fig.12 It is a schematic diagram of the kinetic model fitting analysis at 50°C of the present invention.

[0032] Fig.13 It is a schematic diagram of the kinetic model fitting analysis at 60°C of the present invention. DETAILED DESCRIPTION

[0033] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0034] Example: Take the hydration heat test results of a gold mine cemented filling body at different temperatures as an example: like Figure 1As shown in the figure, the cementitious material used in the preparation of cemented filling body is 42.5R ordinary Portland cement; the tailings come from the waste after beneficiation of a gold mine of Shandong Gold Group, and the main chemical components are silicon dioxide and aluminum oxide, which account for 71.16% and 13.40% respectively by mass percentage, and the rest are small amounts of compounds such as potassium oxide (less than 5% by mass); the waste is dried and ground to obtain the whole tailings used in the experiment, and the size of the tailings is less than 1mm; the mixing water is tap water in the laboratory; The slurry material was prepared with a lime-sand ratio of 1:6 and a concentration of 70%. After stirring evenly, the slurry was placed in a 20 mL centrifuge tube for testing. The test time was controlled at 7 days. In order to avoid the phenomenon of slow slurry temperature rise during the initial measurement process, the material and water were heated before stirring to ensure that the material temperature was consistent with the curing temperature. The isothermal calorimetry method was used to obtain the heat release and heat release rate test results of the hydration reaction of cemented filling at different temperatures. Figure 2 It can be seen that the increase in temperature causes the main exothermic peak to shift to the left, the arrival time of the maximum exothermic rate appears earlier accordingly, and the time of the exothermic peak is shortened as a whole. Under the curing conditions of 20-60℃, the maximum exothermic rates of the main exothermic peak are 3.89, 4.90, 11.52, 17.89, and 24.16 J / gh, respectively, and the maximum exothermic rate of the main exothermic peak increases significantly. Further, it can be seen from the cumulative heat release diagram that under the curing conditions of 20-60℃, the cumulative heat release of the hydration reaction after the curing age of 168h is 208.35, 230.31, 243.83, 213.18, and 219.69 J / g, respectively. The cumulative heat release does not increase continuously with the increase in the heat release rate, and the heat release reaches the maximum value when the curing temperature is 40℃. Since the hydrolysis rate determines the speed of heat release, the increase of curing temperature increases the hydrolysis rate of cementitious materials in water, so the heat release rate is increased by accelerating the curing temperature; excessive heat release rate increases the diffusion migration barrier of unreacted materials in the cementitious materials, hindering the full occurrence of hydration reaction; the heat release reaches the maximum value when the curing temperature is 40℃; The model assumes that the nucleation rate of the crystal nucleus is a constant I v ; The number of crystal nuclei per unit volume is N v ; The radial growth rate of the crystal nucleus is G; Considering that the crystal nucleus is an ellipsoidal growth mode, the growth mode of the crystal nucleus is divided into two parts: the normal direction and the tangential direction. It is assumed that the ratio of the tangential growth rate to the normal growth rate is g; The normal length a of the crystal nucleus from time t to time t is a=G(t- ), then the tangential length b of the crystal nucleus in the same time is b=gG(t- ); With the tangential direction of the crystal nucleus as the X-axis, a rectangular coordinate system is constructed, such as Figure 3 As shown, the Y and Z directions are the annular growth directions of the crystal nucleus, and the origin is the contact center between the crystal nucleus and the solid particle; considering the circular plane with a thickness of dx at a distance x from the nucleation surface in the X direction, its area is calculated as: It is assumed that the generated nuclei do not interfere with each other, and the nucleation rate constant I v , the total nominal area of ​​all nuclei along the normal X direction at different times can be obtained as: Calculate the nominal area S e Since adjacent nuclei will come into contact during the growth process, the overlapping area is calculated twice during the calculation process, which increases the total area of ​​the nuclei. The percentage of the total area increment reduced by the overlapping of adjacent nuclei is equal to the total area fraction of the actual generated nuclei. The nominal nucleus area S is obtained by calculation. e The relationship between the actual crystal nucleus area S is: (1) Where S is the actual crystal nucleus area; x is the distance from the nucleation surface; t is the specific time of crystal nucleus growth; integrating the actual crystal nucleus area can obtain the nominal volume fraction of the ellipsoid in the entire space. Similarly, it is assumed that the percentage of the total volume increment reduced by the overlap of adjacent crystal nuclei is equal to the total volume fraction of the actually generated crystal nuclei. Finally, the actual total volume fraction of the crystal nucleus growth process can be obtained as: (3) Among them, SA V is the total nucleation surface area per unit volume. The hydration heat comparison analysis was performed using 1stopt5.0 software. The fitting degree was relatively poor, and the reaction rates obtained by theoretical calculation were all higher than the measured results. The main reason was that in the theoretical study, the growth rate, nucleation rate and other parameters were kept constant to simplify the calculation. In the actual reaction, the hydration products gradually increased with the increase of hydration time, which seriously hindered the hydration space of the cementitious material in the filling body. The reaction rates would be weakened accordingly. The theoretical analysis overestimated the hydration reaction process.

[0035] The boundary nucleation-growth model is optimized based on the characteristics of tailings. The roles of tailings in cemented filling mainly include dilution, dissolution and nucleation. The dilution effect refers to the use of tailings to replace part of the cement to reduce the overall cement content and increase the overall water-cement ratio (the mass ratio of water to cement); the dissolution effect increases the water-cement ratio, causing the dissolution rate between water and cement to change; the nucleation effect refers to the tailings can be used as a nucleation surface to provide a storage location for hydration products, and the nucleation efficiency of hydration products per unit area of ​​tailings is lower than that of cement particles. The nucleation rate and growth rate of the hydration reaction have changed, and the changes in each rate are relatively complex. In order to simplify the calculation model, the changes in the main influencing factors are considered, the constant growth rate is changed to a variable growth rate, and the nucleation rate influencing factor is introduced to optimize the nucleation rate; The relationship between nucleation rate and curing temperature is obtained through fitting results: Furthermore, the nucleation rate of the cemented filling body in the growth space is optimized as follows: Where, MI v1 is the nucleation rate of the corrected cemented filling body; I0 is the factor affecting the nucleation rate.

[0036] The growth rate is analyzed and it is believed that the normal growth rate of the cemented filling body crystal nucleus is related to the hydration time, which is G( ). Consider the normal length a of the crystal nucleus from time x to time t as: (6) The total nominal area S1 of all the crystal nuclei of the cemented filling body at different times along the normal X direction is further obtained. e for: (8) The actual total area of ​​the nucleus S1 is obtained by integration: (7) Integrating the actual nucleus area, the nominal volume fraction of the ellipsoid in the entire space is obtained as: In the formula, SA V1 is the total nucleation surface area of ​​the cemented filling body within a unit volume. Due to the nucleation effect of tailings in the cemented filling body, both cement and tailings provide nucleation points for hydration products inside the cemented filling body system. Therefore, the nucleation effect factor is introduced to optimize the total nucleation surface area per unit volume. The calculation formula is: (9) In the formula, S t is the specific surface area of ​​tailings; f t is the ratio of tailings to solid mass, that is, the amount of tailings added; M0 is the influencing factor of nucleation.

[0037] The actual total score is finally obtained: (10) Consistent with the boundary nucleation-growth model analysis, the proportional coefficient A1 is introduced into the modified boundary nucleation-growth model to achieve the corresponding characterization between the volume fraction of hydration products and the hydration heat release Q. At the same time, when conducting the hydration heat test, due to the errors caused by the operation and the extremely fast initial reaction rate of cement, the test data measured within the initial 1h have large errors. Therefore, the test data are optimized before fitting, the data within 1h are eliminated, and then the cumulative heat release of 1h is counted as 0; to compensate for the heat release within 1h, the parameter B1 is added to the final equation, and the modified boundary nucleation-growth model is finally obtained: (11) The revised hydration kinetic model contains five parameters: nucleation rate influencing factor I0, nucleation effect influencing factor M0, growth rate G, proportional coefficient A1 and variable B1. Since there are many variables to be calculated and the growth rate is a variable, the revised boundary nucleation-growth model calculation is based on the results obtained by the boundary nucleation-growth model: the initial nucleation rate is calculated according to the boundary nucleation-growth model; then the corresponding values ​​of the growth rate G and time are calculated based on the initial nucleation rate; and then the revised boundary nucleation-growth model is used to calculate the values ​​of the remaining parameters.

[0038] The growth rate changes at different curing temperatures were calculated, and then the critical length of the crystal nucleus was determined based on the normal growth rate. The calculation results are as follows: Figure 4-Figure 8 As shown in the figure, the normal growth rate G is calculated by modifying the boundary nucleation-growth model, and the critical length value Gt can be determined by integrating the normal growth rate. It can be seen that the normal growth rate increases rapidly in the early stage and then decreases slowly until the rate approaches 0, and finally the nucleus length gradually stabilizes at a fixed value. When the curing temperature increases from 20℃ to 60℃, the maximum normal growth rate generated during the hydration reaction is 0.074 μm / h, 0.102 μm / h, 0.140 μm / h, 0.145 μm / h, and 0.151 μm / h. After the nucleus length stabilizes, it is 0.657 μm, 0.692 μm, 2.013 μm, 2.218 μm, and 2.351 μm, respectively. The overall trend is increasing, indicating that high temperature has a certain role in promoting the extension of the nucleus length. On the other hand, the normal growth rate increases rapidly in the early stage and then decreases slowly until the rate approaches 0. Finally, the nucleus length gradually stabilizes at a fixed value, and its change pattern is consistent with the "local growth hypothesis".

[0039] The measured results of heat release and heat release rate of cemented filling under different temperature conditions are compared with the fitting results. Figure 9-13As shown, it can be seen that the calculation results using the modified boundary nucleation-growth model can better match the measured results, more accurately characterize the changes in heat release during the early hydration process, and have a better fitting effect; the modified boundary nucleation-growth model changes the growth rate of the hydration reaction. The growth rate increases rapidly in the early stage of hydration and gradually decreases as the hydration reaction proceeds. The description using a variable growth rate is more in line with the actual growth pattern of the hydration product, making the hydration exothermic curve closer to the measured results; the fitting effect is greatly improved by changing the growth rate, indicating that the growth rate has a more important influence on the hydration model, and the growth rate of the crystal nucleus determines the overall process of the hydration reaction.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for constructing a hydration kinetic model of cemented filling under temperature effect, characterized in that: The steps include: Step 1: Select cementitious materials, tailings and water as materials for preparing cemented filling body, conduct indoor hydration heat experiment of cemented filling body, and measure the hydration heat release and heat release rate of cemented filling body under the condition of 20-60℃; Step 2: Use the boundary nucleation-growth model to verify the hydration heat experimental results and calculate the nucleation rate I of the hydration product at different temperatures v , constant normal growth rate G value; Step 3: Change the constant normal growth rate to the variable normal growth rate, introduce the nucleation rate influence factor I0 and the nucleation effect influence factor M0 to correct the boundary nucleation-growth model, and obtain the corrected hydration kinetic model; Step 4: Calculate the normal growth rate and critical length of the hydration product nucleus of the modified hydration kinetic model through the control variable method, and verify the accuracy of the modified boundary nucleation-growth model.

2. The method for constructing a hydration dynamics model of cemented filling body under temperature effect according to claim 1, characterized in that: Step 1: Indoor hydration heat experiment is carried out by isothermal calorimetry; The cementitious material is 42.5R ordinary Portland cement; the tailings are waste after mineral processing, and the waste is dried and ground to obtain the whole tailings used in the experiment, and the size of the whole tailings is less than 1mm; the water is tap water in the laboratory.

3. The method for constructing a hydration dynamics model of cemented filling body under temperature effect according to claim 2, characterized in that: In the step 1, the mass ratio of the cementitious material to the tailings is 1:6, and the slurry material is prepared at a concentration of 70% of the solid mass to the total mass ratio, the solid mass is the cementitious material and the tailings, and the total mass is the cementitious material, the tailings and water. After stirring evenly, the slurry is placed in a centrifuge tube for testing; Heat the materials and water before stirring to ensure that the material temperature is consistent with the curing temperature.

4. The method for constructing a hydration dynamics model of cemented filling body under temperature effect according to claim 3, characterized in that: When verifying the results of the hydration heat experiment in step 2, crystal nuclei are generated on the surface of solid particles formed by 42.5R ordinary Portland cement and whole tailings. When the hydration reaction occurs, the generated crystal nuclei grow and diffuse outward in the form of an ellipsoid based on the solid particles. When adjacent crystal nuclei grow to contact each other, the contacted positions will stop growing further; In the boundary nucleation-growth model, the nucleation rate of the crystal nucleus is set to a constant I v ; The number of crystal nuclei per unit volume is N v ; The radial growth rate of the crystal nucleus is G; the ratio of the tangential growth rate to the normal growth rate is set to g; The percentage of the total area increment reduced by the overlap of adjacent crystal nuclei is set to be equal to the total area fraction of the crystal nuclei actually generated. The actual area of ​​a single crystal nucleus is: (1) Where S is the actual nucleus area; x is the distance from the nucleation surface; t is the specific time of nucleus growth; Integrating the actual nucleus area gives the nominal volume fraction of the ellipsoid in the entire space: (2) Among them, V e is the nominal volume fraction of the crystal nucleus; SA V is the total nucleation surface area per unit volume; Let x=uGt, then dx=Gtdu; u is another variable set; The percentage of the total volume increment reduced by the overlap of adjacent nuclei is set to be equal to the total volume fraction of the nuclei actually generated. The actual total volume fraction of the nucleus growth process is obtained by integrating the nominal volume fraction: (3)。 5. The method for constructing a hydration dynamics model of cemented filling body under temperature effect according to claim 4, characterized in that: Step 2 introduces the proportionality coefficient A, which is a constant value for quantifying the volume fraction and the hydration heat release. V is the actual total volume fraction of the crystal nucleus growth process, and the quantitative characterization relationship between the crystal nucleus volume fraction and the hydration heat release Q is achieved as follows: (4) The nonlinear curve fitting software 1stopt5.0 was used to calculate the proportional coefficient A and nucleation rate I in the boundary nucleation-growth model. v , the fitting acquisition of the normal growth rate G parameter, the model theoretical curve is obtained by parameter calculation, and the experimental curve is compared with the model theoretical curve; The nucleation rate I obtained by analyzing the fitting results v , the relationship between the normal growth rate G and the curing temperature, and the curing temperature is used to quantitatively characterize the nucleation rate and the normal growth rate.

6. The method for constructing a hydration dynamics model of cemented filling body under temperature effect according to claim 5, characterized in that: In step 3, the nucleation rate influencing factor I0 is introduced to optimize the nucleation rate. First, the nucleation rate is optimized to optimize the nucleation rate of the cemented filling body in the growth space as follows: (5) Among them, MI v is the nucleation rate of the corrected cemented filling body; I v Nucleation rate of cemented filling at different temperatures.

7. The method for constructing a hydration dynamics model of cemented filling body under temperature effect according to claim 6, characterized in that: In step 3, the normal growth rate G of the cemented filling body crystal nucleus and the hydration time are defined as G( ); the normal length a of the crystal nucleus from time x to time t is: (6) According to the nucleation rate constant MI v1 , the actual total area of ​​the crystal nucleus S1 is obtained by integration: (7) Among them, S1 is the actual crystal nucleus area after correction; integrating the actual crystal nucleus area, the nominal volume fraction of the ellipsoid in the entire space is obtained as: (8) Among them, V1 e is the nominal volume fraction after correction of the crystal nucleus; SA V1 is the total nucleation surface area of ​​the cemented filling body within a unit volume. The nucleation influencing factor is introduced to optimize the total nucleation surface area of ​​the cemented filling body within a unit volume. The calculation formula is: (9) Among them, S t is the specific surface area of ​​tailings; f t is the ratio of tailings to solid mass; M0 is the influencing factor of nucleation.

8. The method for constructing a hydration dynamics model of cemented filling body under temperature effect according to claim 7, characterized in that: Step 3: The actual total volume fraction of the total nucleation surface area of ​​the cemented filling body within the unit volume space in its growth space is: (10) The proportional coefficient A1 is introduced, and the parameter B1 is added to control the initial heat release, and finally the modified boundary nucleation-growth model, that is, the hydration kinetic model is obtained: (11)。 9. The method for constructing a hydration dynamics model of cemented filling body under temperature effect according to claim 1, characterized in that: Step 4: The modified hydration kinetic model contains five parameters: nucleation rate influencing factor I0, nucleation effect influencing factor M0, normal growth rate G, proportionality coefficient A1 and parameter B1; the modified boundary nucleation-growth model calculation is performed based on the results obtained from the boundary nucleation-growth model; the initial nucleation rate is calculated according to the boundary nucleation-growth model analysis; subsequently, the corresponding values ​​of the normal growth rate and the hydration time are inversely calculated based on the initial nucleation rate, and then brought into the modified boundary nucleation-growth model to obtain the values ​​of the remaining parameters; Based on the modified boundary nucleation-growth model, the normal growth rate G is calculated at different curing temperatures, and then the critical length Gt of the crystal nucleus is determined; The model calculation results of the heat release and heat release rate of the cemented filling body under different temperature conditions are compared with the measured results.

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