Multi-element solid waste-based ecological mining area filling material and preparation method thereof

Abstract

The invention discloses a multi-element solid-waste-based ecological mining area filling material and a preparation method thereof.The preparation method of the multi-element solid-waste-based ecological mining area filling material comprises the steps that a first system and a second system are mixed to be uniform, slurry is obtained, pouring and standing are conducted till final setting, maintenance is conducted, and the multi-element solid-waste-based ecological mining area filling material is obtained; the first system comprises a foaming agent and first water; the second system comprises a cementing material, second water and a water reducing agent. The multi-element solid waste-based ecological mining area filling material provided by the invention takes the fly ash as a main raw material and is low in cost, the slump expansion degree of the multi-element solid waste-based ecological mining area filling material is up to 272 mm, the uniaxial compressive strength is up to 5.928 MPa, and meanwhile, the multi-element solid waste-based ecological mining area filling material has relatively low plastic viscosity and yield stress.

Description

Technical Field

[0001] This invention belongs to the field of mining area backfilling technology, specifically relating to a multi-element solid waste-based ecological mining area backfilling material and its preparation method. Background Technology

[0002] Inner Mongolia Autonomous Region, as an important coal and energy base in my country, ranks among the top in the country in terms of raw coal production and electricity and heat production. This has resulted in the generation of large quantities of solid waste such as coal gangue, fly ash, and calcium carbide slag. In 2023, Inner Mongolia's annual fly ash production was approximately 70 million tons, while the annual utilization was only about 27 million tons, a utilization rate of less than 50%. Under the combined effects of complex geological structures and extreme climate, mining areas in Inner Mongolia exhibit three high characteristics: high frequency of geological disasters, high difficulty in ecological restoration, and high environmental risks from solid waste storage. Against this backdrop, utilizing fly ash, desulfurization gypsum, and other solid wastes to prepare low-cost underground backfill materials, and promoting the use of solid waste for mine backfilling and ecological restoration, is an important way to solve the ecological problems faced by future coal mining and to scientifically and rationally dispose of solid waste in a short period of time.

[0003] The preparation of high-performance cemented backfill materials for mines based on high-volume solid waste has become a trend. This process uses fly ash, desulfurized gypsum and cement as raw materials. In this process, Ca(OH)2 generated by cement hydration will undergo a secondary pozzolanic reaction with active substances such as SiO2 and Al2O3 in fly ash, and finally generate aluminosilicate gel, which provides strength to the backfill material system and provides technical support for the large-scale resource utilization of industrial solid waste. However, current research still has some shortcomings. For example, when the fly ash content is 20% and 5% carbide slag is added, the physical and mechanical properties of the modified high-water material can be comparable to those of the pure high-water material, but the total solid waste content is only 25% and the cost advantage is insufficient (Shi Song, Liu Changwu, Wu Haikuan, et al. Study on physical and mechanical properties of high-water backfill material modified by fly ash-carbide slag double admixture [J]. Materials Reports, 2021, 35 (07): 7027-7032.). Although the desulfurized gypsum-gasification slag-bottom ash composite system optimized by response surface methodology achieves efficient utilization of solid waste, it exhibits a hydration degradation phenomenon where the 28-day compressive strength is abnormally lower than the 7-day compressive strength (Yang Ke, Zhao Xinyuan, He Xiang, et al. Basic theory and technical system for green backfilling of multi-source coal-based solid waste [J]. Journal of Coal Science and Technology, 2022, 47 (12): 4201-4216.). Although the coal gangue-gasification slag system designed based on Talbol gradation theory has good cementing properties, its slump expansion is only 145 mm, which is difficult to meet the requirements of long-distance pumping (Qu Huisheng, Suo Yonglu, Liu Lang, et al. Preparation and performance of modified coal gasification slag-based mine backfill materials [J]. Journal of Coal Science and Technology, 2022, 47 (05): 1958-1973.). Current technologies still face multiple constraints: on the one hand, the excessively high proportion of ordinary cement-based binders leads to backfilling costs reaching 50% of the total mining cost, highlighting an economic bottleneck; on the other hand, there is a significant contradiction between increasing solid waste content and maintaining material performance, such as the fact that high-content systems are often accompanied by prolonged setting time and decreased early strength. How to construct a synergistic mechanism of "high solid waste content - low cost - high performance" is an urgent problem to be solved in the field of mining backfill materials.

[0004] In addition, slump expansion is an important indicator of mine backfill materials and has attracted much attention. However, the prediction of slump expansion of mine backfill materials is currently a technological gap. Therefore, it is necessary to propose a method that can accurately predict the slump expansion of mine backfill materials. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a method for preparing a multi-element solid waste-based ecological mining area backfill material.

[0006] Another objective of this invention is to provide a multi-element solid waste-based ecological mining area filling material obtained by the above preparation method.

[0007] Another objective of this invention is to provide a method for predicting the collapse expansion of multi-component solid waste-based ecological mining backfill materials.

[0008] The objective of this invention is achieved through the following technical solution.

[0009] A method for preparing a multi-component solid waste-based ecological mining area backfill material includes: mixing a first system and a second system until homogeneous to obtain a slurry, pouring it, allowing it to stand until final setting, and curing it to obtain the multi-component solid waste-based ecological mining area backfill material; the first system includes: a foaming agent and a first water; the second system includes: a cementitious material, a second water, and a water-reducing agent.

[0010] The ratio of foaming agent, first water, cementitious material, second water and water-reducing agent by mass parts is (1~2.5):(45~100):(180~560):(80~350):(0.5~6); the cementitious material is a mixture of cement, fly ash and desulfurized gypsum, and the ratio of cement, fly ash and desulfurized gypsum by mass parts is (30~280):(100~320):(10~150).

[0011] In the above technical solution, the method for obtaining the first system includes: mixing the foaming agent and the first water to obtain a foaming agent solution, and stirring to make the foaming agent solution foam until the foaming ratio is 1 to 5.

[0012] In the above technical solution, the preferred ratio of foaming agent, first water, cementing material, second water and water-reducing agent by mass parts is (1~2.5):(45~90):(180~560):(80~310):(0.5~4.5), and even more preferably (1.9~2.1):(80~85):(180~200):(90~120):(0.5~1.5); the cementing material is a mixture of cement, fly ash and desulfurized gypsum, and the preferred ratio of cement, fly ash and desulfurized gypsum by mass parts is (30~280):(100~300):(10~100), and even more preferably (50~70):(100~150):(10~30).

[0013] In the above technical solution, the foaming ratio is preferably 1 to 3, and more preferably 1 to 1.5.

[0014] In the above technical solution, the foaming agent is a plant protein foaming agent.

[0015] In the above technical solution, the water-reducing agent is a polycarboxylate-based water-reducing agent.

[0016] In the above technical solution, the settling time is 12~24h.

[0017] In the above technical solution, the method for obtaining the second system includes: mixing the cementitious material and the second water until uniform, adding the water-reducing agent, and mixing until uniform.

[0018] In the above technical solution, the first system and the second system are mixed and stirred until homogeneous.

[0019] In the above technical solutions, the curing time is 7 to 28 days.

[0020] In the above technical solution, the temperature of the maintenance environment is 19.5~20.5℃, and the relative humidity of the maintenance environment is 85~95%.

[0021] The multi-element solid waste-based ecological mining area filling material obtained by the above preparation method.

[0022] In the above technical solution, the maximum slump expansion of the multi-element solid waste-based ecological mining area filling material is 272 mm, and the maximum uniaxial compressive strength is 5.928 MPa.

[0023] A method for predicting the slump expansion of multi-component solid waste-based ecological mining backfill materials includes the following steps:

[0024] S1, taking the slump expansion of the multi-component solid waste-based ecological mining area backfill material as the dependent variable, and the corresponding water-cement ratio, fly ash content, desulfurized gypsum content, foaming ratio, and water-reducing agent content as independent variables, the linear relationship between the dependent variable and the five independent variables is fitted as the flowability multiple linear regression equation: ,in, This refers to the water-to-glue ratio. This refers to the fly ash content. The dosage of desulfurized gypsum. This refers to the foaming ratio. y represents the water-reducing agent dosage; y represents the slump spread. For constant terms, for The corresponding regression coefficients, for The corresponding regression coefficients, for The corresponding regression coefficients, for The corresponding regression coefficients, for The corresponding regression coefficients;

[0025] The water-cement ratio is the mass of the second water divided by the mass of the cementitious material; the fly ash content is the percentage of fly ash in the mass of the cementitious material; the desulfurized gypsum content is the percentage of desulfurized gypsum in the mass of the cementitious material; and the water-reducing agent content is the percentage of water-reducing agent in the mass of the cementitious material.

[0026] In S1, a fluidity multiple linear regression equation is obtained by preparing N multi-element solid waste-based ecological mining area filling materials and fitting them, where N≥6.

[0027] S2, substitute the water-cement ratio, fly ash content, desulfurized gypsum content, foaming ratio and water-reducing agent content of the multi-component solid waste-based ecological mining area backfill material to be predicted into the fluidity multiple linear regression equation to obtain the slump expansion of the multi-component solid waste-based ecological mining area backfill material to be predicted.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] 1. This invention provides a low-cost, multi-element solid waste-based ecological mine filling material using fly ash as the main raw material. This material exhibits a slump spread of up to 272 mm and a uniaxial compressive strength of up to 5.928 MPa, while also possessing low plastic viscosity and yield stress. Using slump spread, yield stress, plastic viscosity, and uniaxial compressive strength as evaluation indicators, this invention obtains the optimal proportion of the multi-element solid waste-based ecological mine filling material. This results in a material with high solid waste content (greater than or equal to 50%), high performance, and low cost, effectively solving the problem of large-scale industrial solid waste storage in the region, improving the mine's ecological and living environment, and promoting green ecological governance in mines.

[0030] 2. This invention uses the slump expansion of multi-component solid waste-based ecological mining area backfill material as the dependent variable, and the corresponding water-cement ratio, fly ash content, desulfurized gypsum content, foaming ratio, and water-reducing agent content of the multi-component solid waste-based ecological mining area backfill material as independent variables. It proposes a method for predicting the slump expansion of multi-component solid waste-based ecological mining area backfill material. This method can accurately predict the slump expansion of multi-component solid waste-based ecological mining area backfill material with an absolute error of less than 10%. Attached Figure Description

[0031] Figure 1 XRD patterns of cement, fly ash, and desulfurized gypsum;

[0032] Figure 2 The trend graph shows the plastic viscosity of the slurries prepared in Examples 1-16;

[0033] Figure 3 The trend graph shows the yield stress of the slurries prepared in Examples 1-16;

[0034] Figure 4 The XRD patterns of the multi-component solid waste-based ecological mining area filling materials prepared in Examples 13-16 are shown below.

[0035] Figure 5 SEM image of the multi-component solid waste-based ecological mining area filling material prepared in Example 13, where b is a partial magnified view of a;

[0036] Figure 6 The elemental analysis diagram of the multi-component solid waste-based ecological mining area filling material prepared in Example 13 is shown below.

[0037] Figure 7 SEM image of the multi-component solid waste-based ecological mining area filling material prepared in Example 14, where b is a partial magnified view of a;

[0038] Figure 8 The elemental analysis diagram of the multi-component solid waste-based ecological mining area filling material prepared in Example 14 is shown below.

[0039] Figure 9 SEM image of the multi-component solid waste-based ecological mining area filling material prepared in Example 15, where b is a partial magnified view of a;

[0040] Figure 10 The elemental analysis diagram of the multi-component solid waste-based ecological mining area filling material prepared in Example 15 is shown below.

[0041] Figure 11 SEM image of the multi-component solid waste-based ecological mining area filling material prepared in Example 16, where b is a partial magnified view of a;

[0042] Figure 12 The elemental analysis diagram is shown for the multi-element solid waste-based ecological mining area filling material prepared in Example 16.

[0043] exist Figure 2 and Figure 3 In the text, "L1" represents Example 1, "L2" represents Example 2, "L3" represents Example 3, "L4" represents Example 4, "L5" represents Example 5, "L6" represents Example 6, "L7" represents Example 7, "L8" represents Example 8, "L9" represents Example 9, "L10" represents Example 10, "L11" represents Example 11, "L12" represents Example 12, "L13" represents Example 13, "L14" represents Example 14, "L15" represents Example 15, and "L16" represents Example 16. Detailed Implementation

[0044] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0045] Cement: Grade 42.5 ordinary Portland cement, purchased from Inner Mongolia Jidong Cement Co., Ltd., D50=11.37μm;

[0046] Fly ash: purchased from Donghua Thermal Power Plant in Inner Mongolia, D50=40.86μm;

[0047] Desulfurized gypsum: purchased from Donghua Thermal Power Plant in Inner Mongolia, D50=24.78μm.

[0048] The chemical composition of cement, fly ash, and desulfurized gypsum was determined using a Rigaku Ultima IV X-ray diffractometer, and the results are as follows: Figure 1 As shown. By Figure 1 It can be seen that the main phase composition of cement is tricalcium silicate, tetracalcium silicate, tricalcium aluminate and tetracalcium aluminoferrite, the main phase composition of fly ash is quartz, mullite and hematite, and the main phase composition of desulfurized gypsum is calcined gypsum.

[0049] Polycarboxylate superplasticizer: purchased from Shaanxi Qinfen Building Materials Co., Ltd., pale yellow liquid, density 1.1 g / cm³. 3 The water reduction rate is 37%.

[0050] Plant protein foaming agent: purchased from Dongguan Kaixuan Plastics Technology Co., Ltd., Guangdong Province; density: 1.09 g / cm³ 3 The solid content is 21.8%, and the pH is 6.8.

[0051] In the following embodiments, the temperature of the maintenance environment is 20°C and the relative humidity of the maintenance environment is 90%.

[0052] Foaming ratio (based on density calculation): A foaming agent solution with mass m1 is obtained by mixing the foaming agent and water. The volume of the foaming agent solution is denoted as V1. The density of the foaming agent solution is calculated based on m1 and V1 and denoted as ρ1. The solution is stirred to foam, and the density of the foam after foaming is measured by volumetric weighing and denoted as ρ2. The foaming ratio is essentially the volume ratio before and after foaming. Since only air is introduced during the foaming process, the mass of the foaming agent solution and the mass of the foam after foaming are essentially the same; therefore, the foaming ratio is calculated as ρ1 / ρ2.

[0053] Slump spread: Slump spread is one of the main methods for measuring flowability. Referring to GB / T 51450-2022 "Technical Standard for Backfilling Engineering in Metal and Non-metal Mines" and GB / T 50080-2016 "Standard for Test Methods of Performance of Ordinary Concrete Mixtures", a standard slump bucket with a top diameter of 100mm, a bottom diameter of 200mm, and a height of 300mm and a matching spread base were used to conduct three tests. The average value of the three tests was taken as the slump spread value.

[0054] The rheological properties of the slurry are evaluated by measuring yield stress and plastic viscosity, as these properties directly affect its flow and filling capacity during molding. The specific testing and calculation methods are as follows: The shear stress-shear rate curve of the slurry is measured using a rheometer. First, a shear stress-shear rate curve of 0.5 s⁻¹ is used. -1 The shear rate was pre-sheared for 20 seconds, then held for 10 seconds, and then the shear rate was increased from 0.5 s⁻¹. -1 Reduced to 0.001 s -1 At a shear rate of 0.5 s⁻¹ -1 Reduced to 0.001 s -1 Ten sets of data were collected during the process (the shear rate corresponding to each of the ten sets of data was 0.5 s). -1 0.35 s -1 0.2 s -1 0.1 s -1 0.05 s -1 0.025 s -1 0.01 s -1 0.005 s -1 0.0025 s -1 and 0.001 s -1 Finally, the plastic viscosity and yield stress were calculated using the Bingham model based on the collected data.

[0055] Uniaxial compressive strength: Tests were conducted according to GB / T 51450-2022 "Technical Standard for Backfilling Engineering in Metal and Non-metal Mines" and GB / T 17671-2021 "Test Method for Strength of Cement Mortar". A TB-1 type 600kN microcomputer-controlled electro-hydraulic servo universal testing machine was used, with displacement control loading mode set, and uniaxial compression tests were performed at a rate of (1.00±0.05) mm / min. For each embodiment, multiple valid specimens were selected. After removing abnormal data with a deviation from the mean exceeding 15%, three specimens were randomly selected from the remaining valid specimens, and the arithmetic mean was taken as the final uniaxial compressive strength value.

[0056] Examples 1-16

[0057] A method for preparing a multi-component solid waste-based ecological mining area backfill material includes: adding a first system to a second system, stirring at room temperature until uniform to obtain a slurry, pouring the slurry into a standard cubic mold of 100mm × 100mm × 100mm, vibrating to remove large air bubbles, leveling the mold surface with a scraper, letting it stand for 24 hours until final setting, and curing it in a constant temperature and humidity curing room for 28 days to obtain the multi-component solid waste-based ecological mining area backfill material;

[0058] The method for obtaining the first system includes: mixing a foaming agent and a first water to obtain a foaming agent solution, and stirring it at room temperature in a ZKR-5 type physical foaming machine (working pressure 0.6MPa) to foam the foaming agent solution until the foaming ratio is A, thereby obtaining the first system; the method for obtaining the second system includes: mixing a cementitious material and a second water, stirring at room temperature until homogeneous, adding a water-reducing agent, and stirring at room temperature until homogeneous, thereby obtaining the second system;

[0059] The ratio of foaming agent, first water, cementitious material, second water, and water-reducing agent by mass parts is X. The foaming agent is a plant protein foaming agent, the water-reducing agent is a polycarboxylate-based water-reducing agent, and the cementitious material is a mixture of cement, fly ash, and desulfurized gypsum. The ratio of cement, fly ash, and desulfurized gypsum by mass parts is Y. A, X, and Y are shown in Table 1.

[0060] Table 1

[0061]

[0062] Based on the values ​​of X and Y in Table 1, the "water-cement ratio," "fly ash content," "desulfurized gypsum content," and "water-reducing agent content" were calculated. Table 2 shows the "water-cement ratio," "fly ash content," "desulfurized gypsum content," "foaming ratio," and "water-reducing agent content" for Examples 1-16. The water-cement ratio was calculated as follows: the mass of the second water divided by the mass of the cementitious material; the fly ash content was the percentage of fly ash in the cementitious material's mass; the desulfurized gypsum content was the percentage of desulfurized gypsum in the cementitious material's mass; and the water-reducing agent content was the percentage of water-reducing agent in the cementitious material's mass.

[0063] Table 2

[0064]

[0065] The slump spread and uniaxial compressive strength of the multi-component solid waste-based ecological mining area filling materials prepared in Examples 1-16 were tested, and the slump spread and uniaxial compressive strength obtained are shown in Table 3.

[0066] Table 3

[0067]

[0068] As shown in Table 3, the multi-element solid waste-based ecological mining area filling material prepared in Example 12 exhibits the highest slump expansion and uniaxial compressive strength. Among Examples 1-16, Example 12 represents the optimal technical solution.

[0069] Plastic viscosity is an indicator of the internal frictional resistance of a fluid, reflecting the magnitude of intermolecular forces during fluid flow. The lower the plastic viscosity, the better the fluidity of the slurry and the easier it is to pump. Yield stress is the minimum shear stress required for a fluid to begin flowing. The lower the yield stress, the better the fluidity of the slurry. The slurries prepared in Examples 1-16 were tested for plastic viscosity and yield stress. Specifically, freshly prepared slurries were left to stand, and tests were conducted on slurries at 30 minutes, 60 minutes, and 90 minutes. The trend graphs of the plastic viscosity and yield stress of the slurries are shown below. Figure 2 and Figure 3 As shown. (Through) Figure 2 and Figure 3 It can be seen that with the increase of the water-cement ratio, the plastic viscosity and yield stress of the slurry both show a decreasing trend overall. This is because the more water there is, the thicker the water film layer adsorbed on the surface of the cementitious material particles, effectively reducing the frictional resistance between the cementitious material particles, thereby reducing the plastic viscosity of the slurry and improving the rheological properties of the freshly mixed backfill material (the slurry state that has just been prepared and has not yet hardened). Considering the plastic viscosity and yield stress of the slurry, as well as the slump spread and uniaxial compressive strength of the multi-element solid waste-based ecological mining area backfill material, Example 12 is the better choice.

[0070] The internal microstructure of the multi-component solid waste-based ecological mining area infill material was characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The multi-component solid waste-based ecological mining area infill material was crushed and cleaved (cleavage: breaking it into powder). The cleaved cross-section was taken as a sample. The sample was sputter-coated with gold before characterization tests to eliminate the charging effect of non-conductive samples.

[0071] Figure 4 Example 13 ( Figure 4 (50% solid waste content in the middle), Example 14 ( Figure 4 (60% solid waste content in the middle), Example 15 ( Figure 4 "70% solid waste content" and Example 16 ( Figure 4 XRD pattern of the multi-component solid waste-based ecological mining area backfill material prepared with "80% solid waste content". The solid waste content is the sum of the fly ash content and the desulfurized gypsum content. Figure 4It can be seen that the peak intensity of the quartz phase near 19.6° and 22.0° tends to increase with the increase of solid waste content. Kaolinite appears at 28.9° in Examples 13-16, and calcium silicate appears at 36.0° in Examples 13-16. Calcium silicate and kaolinite are hydration products, indicating that cement and fly ash undergo hydration. The different peak intensities of kaolinite and calcium silicate under different solid waste content indicate that the degree of hydration varies with different solid waste content. Characteristic peaks of ettringite and sodium mica can be detected in Examples 13-16, indicating that as the reaction proceeds, the active glass phase in fly ash dissolves and participates in the reaction to form ettringite (AFt) and sodium mica. Mullite and limestone are reaction byproducts.

[0072] Figure 5 a and Figure 5 b is a SEM image of the multi-element solid waste-based ecological mining area filling material prepared in Example 13, wherein, Figure 5 b is Figure 5 A magnified view of part 'a'. Figure 6 The elemental analysis diagram is shown for the multi-element solid waste-based ecological mining area filling material prepared in Example 13. Figure 7 a and Figure 7 b is a SEM image of the multi-component solid waste-based ecological mining area filling material prepared in Example 14, wherein, Figure 7 b is Figure 7 A magnified view of part 'a'. Figure 8 The elemental analysis diagram is shown for the multi-element solid waste-based ecological mining area filling material prepared in Example 14. Figure 9 a and Figure 9 b is a SEM image of the multi-element solid waste-based ecological mining area filling material prepared in Example 15, wherein, Figure 9 b is Figure 9 A magnified view of part 'a'. Figure 10 The elemental analysis diagram is shown for the multi-element solid waste-based ecological mining area filling material prepared in Example 15. Figure 11 a and Figure 11 b is a SEM image of the multi-element solid waste-based ecological mining area filling material prepared in Example 16, wherein, Figure 11 b is Figure 11 A magnified view of part 'a'. Figure 12 The elemental analysis diagram is shown for the multi-element solid waste-based ecological mining area filling material prepared in Example 16.

[0073] Example 13 (45% fly ash and 5% desulfurized gypsum) and Example 16 (60% fly ash and 20% desulfurized gypsum) were compared. Figure 5 a, Figure 5 b, Figure 11 a and Figure 11 As shown in b, in Figure 11More ettringite (Aft) can be observed in b. Furthermore, from Figure 11 b also shows that, due to the excessive amount of fly ash, a small amount of fly ash that did not participate in the hydration reaction exists in the multi-element solid waste-based ecological mining area filling material prepared in Example 16. Figure 11 (in b, "unhydrated FA").

[0074] Example 17

[0075] A method for predicting the slump expansion of multi-component solid waste-based ecological mining backfill materials includes the following steps:

[0076] S1. Using the water-cement ratio, fly ash content, desulfurized gypsum content, foaming ratio, and water-reducing agent content corresponding to the 16 multi-element solid waste-based ecological mining area backfill materials in Table 2 as independent variables, and the slump expansion degree of the 16 multi-element solid waste-based ecological mining area backfill materials in Table 3 as the dependent variable, the linear relationship between the dependent variable and the five independent variables is fitted as the flowability multiple linear regression equation: , in, This refers to the water-to-glue ratio. This refers to the fly ash content. The dosage of desulfurized gypsum. This refers to the foaming ratio. y represents the water-reducing agent dosage; y represents the slump spread. The fitting was performed using the analysis command in Origin, employing a linear least squares data fitting method.

[0077] S2, substitute the water-cement ratio, fly ash content, desulfurized gypsum content, foaming ratio and water-reducing agent content of the multi-component solid waste-based ecological mining area backfill material to be predicted into the fluidity multiple linear regression equation to obtain the slump expansion of the multi-component solid waste-based ecological mining area backfill material to be predicted.

[0078] Comparative Example 1

[0079] A method for predicting the slump expansion of multi-component solid waste-based ecological mining backfill materials is basically the same as that in Example 17, except that the water-cement ratio ( ), fly ash content ( ), foaming ratio ( ) and water-reducing agent dosage ( Using the collapse spread (y) as the dependent variable and the four independent variables as the dependent variable, a linear relationship between the dependent variable and the four independent variables was fitted to obtain a liquidity multiple linear regression equation. The liquidity multiple linear regression equation obtained in Comparative Example 1 is: .

[0080] Comparative Example 2

[0081] A method for predicting the slump expansion of multi-component solid waste-based ecological mining backfill materials is basically the same as that in Example 17, except that the water-cement ratio ( ), fly ash content ( ), desulfurized gypsum dosage ( ) and foaming ratio ( Using the collapse spread (y) as the independent variable and the collapse spread as the dependent variable, a linear relationship between the dependent variable and the four independent variables was fitted to obtain a liquidity multiple linear regression equation. The liquidity multiple linear regression equation obtained in Comparative Example 2 is: .

[0082] Comparative Example 3

[0083] A method for predicting the slump expansion of multi-component solid waste-based ecological mining backfill materials is basically the same as that in Example 17, except that the water-cement ratio ( ), desulfurized gypsum dosage ( ), foaming ratio ( ) and water-reducing agent dosage ( Using the collapse spread (y) as the dependent variable and the four independent variables as the dependent variable, a linear relationship between the dependent variable and the four independent variables was fitted to obtain the liquidity multiple linear regression equation. The liquidity multiple linear regression equation obtained in Comparative Example 3 is as follows: .

[0084] Comparative Example 4

[0085] A method for predicting the slump expansion of multi-component solid waste-based ecological mining area backfill materials is basically the same as that in Example 17, except that the difference lies only in the fly ash content ( ), desulfurized gypsum dosage ( ), foaming ratio ( ) and water-reducing agent dosage ( Using the collapse spread (y) as the independent variable and the collapse spread as the dependent variable, a linear relationship between the dependent variable and the four independent variables was fitted to obtain a liquidity multiple linear regression equation. The liquidity multiple linear regression equation obtained in Comparative Example 4 is: .

[0086] Comparative Example 5

[0087] A method for predicting the slump expansion of multi-component solid waste-based ecological mining backfill materials is basically the same as that in Example 17, except that the water-cement ratio ( ), fly ash content ( ), desulfurized gypsum dosage ( ) and water-reducing agent dosage ( Using the collapse spread (y) as the independent variable and the collapse spread as the dependent variable, a linear relationship between the dependent variable and the four independent variables was fitted to obtain a liquidity multiple linear regression equation. The liquidity multiple linear regression equation obtained in Comparative Example 5 is: .

[0088] Formula applicability test:

[0089] As a verification example 1, a multi-component solid waste-based ecological mining area backfill material was prepared. The preparation method of verification example 1 includes: adding the first system to the second system, stirring until uniform at room temperature to obtain a slurry, pouring the slurry into a standard cubic mold of 100mm × 100mm × 100mm, vibrating to remove large air bubbles, leveling the surface of the mold with a scraper, letting it stand for 24 hours until final setting, and curing it in a constant temperature and humidity curing room for 28 days to obtain the multi-component solid waste-based ecological mining area backfill material.

[0090] The method for obtaining the first system includes: mixing a foaming agent and a first water to obtain a foaming agent solution, and stirring it at room temperature in a ZKR-5 type physical foaming machine (working pressure 0.6MPa) to foam the foaming agent solution until the foaming ratio is 4, thus obtaining the first system; the method for obtaining the second system includes: mixing a cementitious material and a second water, stirring at room temperature until homogeneous, adding a water-reducing agent, and stirring at room temperature until homogeneous, thus obtaining the second system;

[0091] By mass parts, the ratio of foaming agent, first water, cementing material, second water and water-reducing agent is 2.5:100:433:173.2:4.33. The foaming agent is a plant protein foaming agent, the water-reducing agent is a polycarboxylate water-reducing agent, and the cementing material is a mixture of cement, fly ash and desulfurized gypsum. By mass parts, the ratio of cement, fly ash and desulfurized gypsum is 238.15:173.2:21.65.

[0092] As a verification example 2, a multi-component solid waste-based ecological mining area filling material was prepared. The preparation method of verification example 2 includes: adding the first system to the second system, stirring at room temperature until uniform to obtain a slurry, pouring the slurry into a standard cubic mold of 100mm × 100mm × 100mm, vibrating to remove large air bubbles, leveling the surface of the mold with a scraper, letting it stand for 24 hours until final setting, and curing it in a constant temperature and humidity curing room for 28 days to obtain the multi-component solid waste-based ecological mining area filling material.

[0093] The method for obtaining the first system includes: mixing a foaming agent and a first water to obtain a foaming agent solution, and stirring it at room temperature in a ZKR-5 type physical foaming machine (working pressure 0.6MPa) to foam the foaming agent solution until the foaming ratio is 4, thus obtaining the first system; the method for obtaining the second system includes: mixing a cementitious material and a second water, stirring at room temperature until homogeneous, adding a water-reducing agent, and stirring at room temperature until homogeneous, thus obtaining the second system;

[0094] By mass parts, the ratio of foaming agent, first water, cementing material, second water and water-reducing agent is 2.5:100:479:191.6:4.79. The foaming agent is a plant protein foaming agent, the water-reducing agent is a polycarboxylate water-reducing agent, and the cementing material is a mixture of cement, fly ash and desulfurized gypsum. By mass parts, the ratio of cement, fly ash and desulfurized gypsum is 47.9:311.35:119.75.

[0095] The "water-cement ratio", "fly ash content", "desulfurized gypsum content", "foaming ratio" and "water-reducing agent content" of verification examples 1-2 are shown in Table 4.

[0096] Table 4

[0097]

[0098] Using validation examples 1-2 as the infill materials for the multi-component solid waste-based ecological mining area to be predicted, and substituting them into the flowability multiple linear regression equations in Example 17 and Comparative Examples 1-5, the slump expansion of the infill materials for the multi-component solid waste-based ecological mining area to be predicted is obtained as the fitted value of the slump expansion.

[0099] The slump spread of the multi-component solid waste-based ecological mining area backfill material prepared in Verification Example 1 was tested, and the experimental value of slump spread was 208 mm. Based on the fluidity multiple linear regression equation, the corresponding independent variables of Verification Example 1 were substituted into the fluidity multiple linear regression equations of Example 17 and Comparative Examples 1-5 to obtain the fitted values ​​of slump spread, as shown in Table 5. In Table 5, "Error (%)" = ((fitted value of slump spread - experimental value of slump spread) / experimental value of slump spread) * 100%.

[0100] Table 5

[0101]

[0102] The slump spread of the multi-component solid waste-based ecological mining area backfill material prepared in Verification Example 2 was tested, and the experimental value of slump spread was 221 mm. Based on the fluidity multiple linear regression equation, the corresponding independent variables of Verification Example 2 were substituted into the fluidity multiple linear regression equations of Example 17 and Comparative Examples 1-5 to obtain the fitted values ​​of slump spread, as shown in Table 6. In Table 6, "Error (%)" = ((fitted value of slump spread - experimental value of slump spread) / experimental value of slump spread) * 100%.

[0103] Table 6

[0104]

[0105] According to Tables 5 and 6, the fitted value of the slump expansion calculated by the fluidity multiple linear regression equation of Example 17 of the present invention is closest to the experimental value of the slump expansion obtained by actual testing. The fluidity multiple linear regression equation of Example 17 of the present invention can well predict the slump expansion of the multi-component solid waste-based ecological mining area filling material.

[0106] The present invention has been described above by way of example. It should be noted that any simple modifications, alterations or other equivalent substitutions that can be made by those skilled in the art without creative effort without departing from the core of the present invention fall within the protection scope of the present invention.

Claims

1. A method for preparing a multi-element solid waste-based ecological mining area backfill material, characterized in that, include: The first and second systems are mixed until homogeneous to obtain a slurry, which is then poured, left to stand until final set, and cured to obtain a multi-component solid waste-based ecological mining area filling material. The first system comprises: a foaming agent and a first water; the second system comprises: a cementitious material, a second water, and a water-reducing agent; The ratio of foaming agent, first water, cementitious material, second water and water-reducing agent by mass parts is (1~2.5):(45~100):(180~560):(80~350):(0.5~6); the cementitious material is a mixture of cement, fly ash and desulfurized gypsum, and the ratio of cement, fly ash and desulfurized gypsum by mass parts is (30~280):(100~320):(10~150).

2. The preparation method according to claim 1, characterized in that, The foaming agent is a plant protein foaming agent, and the water-reducing agent is a polycarboxylate-based water-reducing agent.

3. The preparation method according to claim 1, characterized in that, The method for obtaining the first system includes: mixing a foaming agent and a first water to obtain a foaming agent solution, and stirring the foaming agent solution to foam it until the foaming ratio is 1 to 5.

4. The preparation method according to claim 1, characterized in that, The settling time is 12-24 hours.

5. The preparation method according to claim 1, characterized in that, The maintenance period is 7 to 28 days.

6. The preparation method according to claim 5, characterized in that, The temperature of the maintenance environment is 19.5~20.5℃, and the relative humidity of the maintenance environment is 85~95%.

7. The preparation method according to claim 1, characterized in that, The method for obtaining the second system includes: mixing the cementitious material and the second water until homogeneous, adding the water-reducing agent, and mixing until homogeneous.

8. The multi-element solid waste-based ecological mining area filling material obtained by the preparation method according to any one of claims 1 to 7.

9. A method for predicting the slump expansion of the multi-component solid waste-based ecological mining area backfill material as described in claim 8, characterized in that, Includes the following steps: S1, taking the slump expansion of the multi-component solid waste-based ecological mining area backfill material as the dependent variable, and the corresponding water-cement ratio, fly ash content, desulfurized gypsum content, foaming ratio, and water-reducing agent content as independent variables, the linear relationship between the dependent variable and the five independent variables is fitted as the flowability multiple linear regression equation: ,in, This refers to the water-to-glue ratio. This refers to the fly ash content. The dosage of desulfurized gypsum. This refers to the foaming ratio. y represents the water-reducing agent dosage; y represents the slump spread. For constant terms, for The corresponding regression coefficients, for The corresponding regression coefficients, for The corresponding regression coefficients, for The corresponding regression coefficients, for The corresponding regression coefficients; The water-cement ratio is the mass of the second water divided by the mass of the cementitious material; the fly ash content is the percentage of fly ash in the mass of the cementitious material; the desulfurized gypsum content is the percentage of desulfurized gypsum in the mass of the cementitious material; the water-reducing agent content is the percentage of water-reducing agent in the mass of the cementitious material. S2, substitute the water-cement ratio, fly ash content, desulfurized gypsum content, foaming ratio and water-reducing agent content of the multi-component solid waste-based ecological mining area backfill material to be predicted into the fluidity multiple linear regression equation to obtain the slump expansion of the multi-component solid waste-based ecological mining area backfill material to be predicted.

10. The method according to claim 9, characterized in that, By preparing N multi-element solid waste-based ecological mining area filling materials, a fluidity multiple linear regression equation was obtained through fitting, where N≥6.

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