Solid-waste-based cementing agent for desert aeolian sand solidification and preparation method of solid-waste-based cementing agent

Abstract

The invention relates to the technical field of special soil foundation improvement treatment, in particular to a solid waste-based cementing agent for desert aeolian sand solidification and a preparation method of the solid waste-based cementing agent. The solid waste-based cementing agent comprises steel slag, mineral slag, phosphorus slag and carbide slag, and the content of the steel slag is 5 wt%, the content of the mineral slag is 26 wt%-35 wt%, the content of the phosphorus slag is 20 wt%-29 wt%, and the content of the carbide slag is 40 wt%. The solid waste-based cementing agent provides an environment-friendly cementing material for solidification treatment of an aeolian sand foundation in a desert area, and cement replacement in a desert aeolian sand cement solidification technology can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of special soft soil foundation improvement, and particularly to a solid waste-based binder for desert aeolian sand solidification and a preparation method thereof. Background Art

[0002] There are many deserts in China, forming an arc-shaped desert belt from the northwest, north China to the western part of northeast China, with an area of more than 700,000 km 2 . Many major projects and infrastructure related to the national economy and people's livelihood need to be built in the desert hinterland or cross the desert, involving large-scale oil and gas field development, high-speed highway (railway) network projects, large and medium-sized water conservancy projects, west-to-east power transmission projects, communication and aerospace projects, etc. The construction and operation of these major projects face two major challenges: (1) In desert areas, the sun shines strongly, the temperature difference between day and night is large, the wind and sand activities are intense, and wind erosion is serious; (2) Aeolian sand is loose, with extremely fine particle size, poor particle gradation, and almost zero cohesion. Therefore, it is urgent to improve the engineering properties of aeolian sand and solve the bottleneck problems faced by the construction of major infrastructure projects in desert areas. The solidification of aeolian sand foundation is a foundation improvement treatment technology that adapts to the physical and mechanical and mineral composition characteristics of aeolian sand.

[0003] The aeolian sand foundation solidification technology uses a series of physical and chemical reaction products between the solidifying binder and water and minerals in aeolian sand to produce a cementing and filling effect, forming a solidified aeolian sand foundation, which is a "local conditions and local materials" aeolian sand foundation treatment plan. Research at home and abroad shows that: the pH value of natural aeolian sand is 7.5 - 8.9, the mineral composition is relatively stable, generally mainly quartz, followed by feldspar, calcite, mica, etc. The main chemical active component of aeolian sand is amorphous SiO2, with a content of generally about 65%, followed by Al2O3, accounting for about 10%, and CaO accounting for about 8%. The other components are mainly Fe2O3, MgO, Na2O, K2O, etc. Therefore, the mineral composition and its chemical active components of aeolian sand provide a mineral basis for aeolian sand solidification.

[0004] Currently, there are mainly two solidification methods for desert aeolian sand solidification: using inorganic cementing materials such as cement, lime, fly ash, etc. and using organic chemical binders such as emulsified asphalt, polymer emulsion, 1,4-xylene (PX) curing agent, etc. However, the solidification of desert aeolian sand generally still mainly uses cement-based binders. Under the national goals of carbon peak and carbon neutrality, the solidification of aeolian sand with cement-based cementing materials faces environmental protection problems. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems in the related technologies to some extent. For this purpose, the present invention provides a solid waste-based binder for desert aeolian sand solidification and a preparation method thereof. The solid waste-based binder provides an environmentally friendly cementing material for the aeolian sand foundation in desert areas, and can realize the replacement of cement in the cement solidification technology of desert aeolian sand.

[0006] To this end, the first aspect of the present invention provides a solid waste-based binder for solidifying aeolian sand in desert. The solid waste-based binder includes steel slag, slag, phosphorous slag, and carbide slag. Among them, the content of the steel slag is 5wt%, the content of the slag is 26wt% - 35wt%, the content of the phosphorous slag is 20wt% - 29wt%, and the content of the carbide slag is 40wt%.

[0007] The solid waste-based binder provided by the present invention uses industrial waste as raw materials, has environmental and economic benefits, and the effect of solidifying aeolian sand with this solid waste-based binder is slightly better than that of the existing cement for solidifying aeolian sand.

[0008] According to an embodiment of the present invention, the content of the steel slag is 5wt%, the content of the slag is 35wt%, the content of the phosphorous slag is 20wt%, and the content of the carbide slag is 40wt%.

[0009] According to an embodiment of the present invention, the content of the steel slag is 5wt%, the content of the slag is 26.67wt%, the content of the phosphorous slag is 28.33wt%, and the content of the carbide slag is 40wt%.

[0010] According to an embodiment of the present invention, the content of silicon dioxide in the solid waste-based binder is 21.44% - 22.68%, the content of aluminum oxide is 6.27% - 7.32%, the content of iron oxide is 2.10% - 2.17%, and the content of calcium oxide is 51.81% - 52.29%.

[0011] According to an embodiment of the present invention, the silica ratio of the solid waste-based binder is 2.25 - 2.70, the alumina ratio is 2.98 - 3.36, and the lime saturation coefficient is 0.65 - 0.80.

[0012] The second aspect of the present invention provides a method for preparing the solid waste-based binder described in the first aspect. The method includes the following steps:

[0013] Taking the content of Ca / Si / Al / Fe phase oxides in cement production as the control condition, determine the reference percentage of the mass composition of steel slag, slag, phosphorous slag, and carbide slag in the solid waste-based binder mixture;

[0014] According to the reference percentage, adopt the mixed material simplex lattice test method to set the upper limit value and the lower limit value of the content of steel slag, slag, phosphorous slag, and carbide slag. Among them, the upper limit value increases by 8 - 20 percentage points on the basis of the reference percentage, and the lower limit value decreases by 3 - 14 percentage points on the basis of the reference percentage;

[0015] According to the upper and lower limit values of the reference percentages of steel slag, slag, phosphorus slag, and carbide slag, the enhanced simplex lattice test method is adopted to obtain steel slag, slag, phosphorus slag, and carbide slag compositions with different percentage contents. The compositions are respectively mixed with aeolian sand to obtain experimental groups, and cement and aeolian sand are mixed according to the same mass admixture ratio of the experimental groups to obtain a control group. The unconfined compressive strength tests are respectively carried out on the experimental groups and the control group, and the target composition is screened according to the test results to obtain the solid waste-based binder.

[0016] According to the embodiments of the present invention, the calculation method of the reference percentage is as follows:

[0017] The masses of steel slag, slag, phosphorus slag, and carbide slag, namely m_steel slag, m_slag, m_phosphorus slag, and m_carbide slag, are calculated through the formula group (I);

[0018]

[0019] According to the obtained masses of steel slag, slag, phosphorus slag, and carbide slag, the mass percentages of steel slag, slag, phosphorus slag, and carbide slag in the solid waste-based binder are calculated, so as to obtain the reference percentage;

[0020] where A Si 、A Al 、A Fe 、A Ca respectively represent the mass content percentages of silicon dioxide, aluminum oxide, iron oxide, and calcium oxide in the steel slag;

[0021] B Si 、B Al 、B Fe 、B Ca respectively represent the mass content percentages of silicon dioxide, aluminum oxide, iron oxide, and calcium oxide in the slag;

[0022] C Si 、C Al 、C Fe 、C Ca respectively represent the mass content percentages of silicon dioxide, aluminum oxide, iron oxide, and calcium oxide in the phosphorus slag;

[0023] D Si 、D Al 、D Fe 、D Ca respectively represent the mass content percentages of silicon dioxide, aluminum oxide, iron oxide, and calcium oxide in the carbide slag;

[0024] W is the mass of silicon dioxide in 100 g of cement, X is the mass of aluminum oxide in 100 g of cement, Y is the mass of ferric oxide in 100 g of cement, and Z is the mass of calcium oxide in 100 g of cement.

[0025] According to an embodiment of the present invention, the average value of W is 20.59 g, the average value of X is 5.02 g, the average value of Y is 3.56 g, and the average value of Z is 63.56 g.

[0026] According to an embodiment of the present invention, the specific steps of the enhanced simplex lattice test method are as follows:

[0027] Set a regular tetrahedron, use the four solid waste materials of steel slag, slag, phosphorus slag, and carbide slag as four components, set each edge of the regular tetrahedron to three equal - value distances, generate 20 enhanced simplex test lattice points with uniform distribution. Each test lattice point is composed of the grading ratio combination of the four solid waste materials and satisfies that the sum of all component ratios is 100%;

[0028] Set 1 center point and 4 axis points as additional test lattice points to capture the non - linear effect inside the enhanced simplex regular tetrahedron. Among them, the center point refers to the geometric center of the enhanced simplex regular tetrahedron, and the component ratio of the center point is the first quarter of the corresponding upper and lower limit ranges of the four solid waste materials; the component ratio of the axis point is equal to the average value of the center point and the vertex;

[0029] Add 1 basic point according to the reference percentage, so as to obtain 26 enhanced simplex test lattice points.

[0030] The beneficial effects of the present invention compared with the prior art:

[0031] (1) Since the steel slag, slag, phosphorus slag, and carbide slag are formed under different industrial production conditions, their Ca / Si / Al / Fe phase oxide contents and activities are different. The present invention first measures the Ca / Si / Al / Fe phase oxide contents of each solid waste material, takes the three - rate values (silica ratio, alumina ratio, and lime saturation coefficient) in cement industrial production as control conditions, and determines the reference percentage of each solid waste material in the mixture, realizing that the main oxide contents of Ca / Si / Al / Fe phases in the solid - waste - based aeolian sand binder are similar to those of the cement binder material;

[0032] (2) Adopt the mixture simplex lattice test method, reasonably determine the upper and lower limit values of the ratio of each solid waste material according to the reference percentage, and then adopt the enhanced simplex lattice test method to carry out the unconfined compressive strength comparison test of cement and solid - waste - based binder for solidifying aeolian sand under the same mass ratio, thus inventing a preparation method of solid - waste - based binder with double - control of the three - rate values of each solid waste material in the solid - waste - based binder and the unconfined compressive strength of solidified aeolian sand;

[0033] (3) According to the unconfined compressive strength comparison test of aeolian sand with 9% water content cured by cement and solid waste-based binder at the same dosage (11%), when the mass ratio of steel slag, slag, phosphorus slag, and carbide slag in the solid waste-based binder is 5.0%: 35%: 20.0%: 40.0%, the unconfined compressive strength of aeolian sand cured by the solid waste-based binder is higher than that of aeolian sand cured by cement under the same dosage condition; in addition, when the mass ratio of steel slag, slag, phosphorus slag, and carbide slag is 5.0%: 26.67%: 28.33%: 40.0%, the strength of aeolian sand cured by the solid waste-based binder is equal to that of aeolian sand cured by cement. Therefore, the solid waste-based binder obtained by the method provided by the present invention can replace the traditional cement binder and realize the resource utilization of large amounts of solid waste.

[0034] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0036] Figure 1 Shows the method for measuring the content of oxides in steel slag, slag, phosphorus slag, and carbide slag used in the present invention;

[0037] Figure 2 Shows the calculation method of the oxide content and the three ratio values in the solid waste-based binder provided by the present invention;

[0038] Figure 3 Shows the enhanced simplex lattice test method used in the present invention;

[0039] Figure 4 Shows the unconfined compressive strength values of 26 test lattice points provided by the present invention and the comparison chart of their unconfined compressive strength with that of aeolian sand cured by cement at the same dosage. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] The embodiments of the present invention will be described in detail below. The embodiments described below are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0041] It should be noted that the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. Further, in the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more.

[0042] The endpoints and any values in the ranges disclosed herein are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the values between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0043] To facilitate the understanding of the present invention, certain technical and scientific terms are specifically defined below. Unless otherwise clearly defined elsewhere in this document, all other technical and scientific terms used herein have the meanings commonly understood by those of ordinary skill in the art to which the present invention pertains.

[0044] In this document, the term "comprising" or "including" is an open-ended expression, that is, it includes the content specified by the present invention, but does not exclude other aspects.

[0045] In this document, the terms "optionally", "optional" or "option" generally mean that the subsequent events or conditions may or may not occur, and this description includes the cases where the events or conditions occur and the cases where the events or conditions do not occur.

[0046] According to an embodiment of the present invention, a solid waste-based binder for solidifying desert aeolian sand is provided in the first aspect of the present invention. The solid waste-based binder includes steel slag, slag, phosphorous slag, and carbide slag. Among them, the content of the steel slag is 5 wt%, the content of the slag is 26 wt% - 35 wt%, the content of the phosphorous slag is 20 wt% - 29 wt%, and the content of the carbide slag is 40 wt%.

[0047] The solid waste-based binder provided by the present invention utilizes the series of physical and chemical reaction products between the Ca / Si / Al phase oxides in steel slag, slag, phosphorous slag, and carbide slag and the water and minerals in desert aeolian sand to produce a cementing and filling effect, and forms a solidified aeolian sand cementitious system jointly composed of aeolian sand - solid waste-based binder - hydration products, thereby forming solidified aeolian sand. The main sources of the strength of the solidified aeolian sand formed by the solid waste-based binder are the cementing strength and the compaction strength.

[0048] According to a specific embodiment of the present invention, the content of the steel slag is 5 wt%, the content of the slag is 35 wt%, the content of the phosphorous slag is 20 wt%, and the content of the carbide slag is 40 wt%.

[0049] According to a specific embodiment of the present invention, the content of the steel slag is 5 wt%, the content of the slag is 26.67 wt%, the content of the phosphorous slag is 28.33 wt%, and the content of the carbide slag is 40 wt%.

[0050] According to specific embodiments of the present invention, the content of silicon dioxide in the solid waste-based binder is 21.44% - 22.68%, the content of aluminum oxide is 6.27% - 7.32%, the content of iron oxide is 2.10% - 2.17%, and the content of calcium oxide is 51.81% - 52.29%.

[0051] According to specific embodiments of the present invention, the silica modulus of the solid waste-based binder is 2.25 - 2.70, the alumina modulus is 2.98 - 3.36, and the lime saturation coefficient is 0.65 - 0.80.

[0052] According to an embodiment of the present invention, a second aspect of the present invention provides a method for preparing the solid waste-based binder described in the first aspect, and the method includes the following steps:

[0053] Taking the content of Ca / Si / Al / Fe phase oxides in cement production as a control condition, determine the reference percentages of the mass composition of steel slag, slag, phosphorus slag, and carbide slag in the solid waste-based binder mixture;

[0054] According to the reference percentages, adopt the mixed material simplex lattice test method to set the upper limit value and the lower limit value of the content of steel slag, slag, phosphorus slag, and carbide slag. Among them, the upper limit value increases by 8 - 20 percentage points based on the reference percentage, and the lower limit value decreases by 3 - 14 percentage points based on the reference percentage;

[0055] According to the upper limit value and the lower limit value of the reference percentages of steel slag, slag, phosphorus slag, and carbide slag, adopt the enhanced simplex lattice test method to obtain steel slag, slag, phosphorus slag, and carbide slag compositions with different percentage contents. Respectively mix the compositions with aeolian sand to obtain experimental groups, and mix cement and aeolian sand according to the same mass admixture ratio of the experimental groups to obtain a control group. Conduct unconfined compressive strength tests on the experimental groups and the control group respectively, and screen out the target composition according to the test results to obtain the solid waste-based binder.

[0056] According to specific embodiments of the present invention, the calculation method of the reference percentage is as follows:

[0057] Calculate the mass of steel slag, slag, phosphorus slag, and carbide slag through the formula group (I), that is, m_steel slag, m_slag, m_phosphorus slag, m_carbide slag;

[0058]

[0059] According to the obtained mass of steel slag, slag, phosphorus slag, and carbide slag, calculate the mass percentages of steel slag, slag, phosphorus slag, and carbide slag in the solid waste-based binder respectively, so as to obtain the reference percentage;

[0060] Among them, A Si , A Al , A Fe , A Ca respectively represent the mass percentage contents of silicon dioxide, aluminum oxide, iron(III) oxide, and calcium oxide in the steel slag;

[0061] B Si , B Al , B Fe , B Ca respectively represent the mass percentage contents of silicon dioxide, aluminum oxide, iron(III) oxide, and calcium oxide in the slag;

[0062] C Si , C Al , C Fe , C Ca respectively represent the mass percentage contents of silicon dioxide, aluminum oxide, iron(III) oxide, and calcium oxide in the phosphorus slag;

[0063] D Si , D Al , D Fe , D Ca respectively represent the mass percentage contents of silicon dioxide, aluminum oxide, iron(III) oxide, and calcium oxide in the carbide slag;

[0064] W is the mass of silicon dioxide in 100 g of cement, X is the mass of aluminum oxide in 100 g of cement, Y is the mass of iron(III) oxide in 100 g of cement, and Z is the mass of calcium oxide in 100 g of cement.

[0065] According to the specific embodiments of the present invention, the average value of W is 20.59 g, the average value of X is 5.02 g, the average value of Y is 3.56 g, and the average value of Z is 63.56 g.

[0066] According to the specific embodiments of the present invention, the specific steps of the enhanced simplex lattice test method are as follows:

[0067] Set a regular tetrahedron, use the four solid waste materials of steel slag, slag, phosphorus slag, and carbide slag as four components, set each edge of the regular tetrahedron to three equal-distance values, generate 20 enhanced simplex test lattice points with uniform distribution, and each test lattice point is composed of the grading ratio combination of the four solid waste materials, and satisfies that the sum of all component ratios is 100%;

[0068] Set one center point and four axis points as additional test lattice points to capture the non-linear effect inside the enhanced simplex regular tetrahedron. Among them, the center point refers to the geometric center of the enhanced simplex regular tetrahedron, and the component ratio of the center point is the first quarter of the corresponding upper and lower limit ranges of the four solid waste materials; the component ratio of the axis point is equal to the average value of the center point and the vertex;

[0069] Based on the reference percentage, add 1 basis point to obtain 26 enhanced simplex test lattice points.

[0070] Specifically, the actual application process of the method is as follows:

[0071] The inventor first adopted the method of literature research and analysis to obtain the statistical results of the Ca / Si / Al / Fe phase oxide contents of common cements and the corresponding three-ratio values, as shown in Table 1.

[0072] Table 1

[0073]

[0074] As can be seen from Table 1, the average value of the silica content in common cements is 20.59 wt%, the average value of the alumina content is 5.02 wt%, the average value of the ferric oxide content is 3.56 wt%, and the average value of the calcium oxide content is 63.56 wt%.

[0075] Use an X-ray fluorescence (XRF) spectrometer to detect the mass contents of the main oxides such as silica, alumina, ferric oxide, and calcium oxide in steel slag, slag, phosphorus slag, and carbide slag respectively (for details, see Figure 1 ), so as to obtain the main oxide contents of the steel slag (SS), slag (GGBFS), phosphorus slag (PS), carbide slag (CS) and the cement used in the comparative test adopted in the present invention, as shown in Table 2.

[0076] Table 2

[0077]

[0078] Table 2 gives the contents of silica, alumina, ferric oxide, and calcium oxide in steel slag, slag, phosphorus slag, and carbide slag. Combining with the average values of the oxides in common cements provided in Table 1, the mass admixture ratios of the various solid waste materials equivalent to the Ca / Si / Al / Fe phase oxide contents of 100 g of common cement can be calculated using the formula group (II) as steel slag: slag: phosphorus slag: carbide slag = 9.6: 15.8: 27.6: 60.7, with a total of 113.7 g. Further, the mass reference percentage is obtained as steel slag: slag: phosphorus slag: carbide slag = 8.44%: 13.90%: 24.27%: 53.39%. The calculation process of the oxide contents and the three-ratio values in the solid waste-based binder can be referred to Figure 2 .

[0079]

[0080] Taking the reference percentage (i.e., steel slag: slag: phosphorus slag: carbide slag = 8.44%: 13.90%: 24.27%: 53.39%) as a reference, combined with the proportion of each solid waste material in the mixture, the upper and lower limits of the content of each solid waste material in the mixture are determined. Among them: the steel slag is 5% - 30%, the slag is 10% - 35%, the phosphorus slag is 20% - 45%, and the carbide slag is 40% - 65%.

[0081] Next, the enhanced simplex lattice test method (as Figure 3 shown) is adopted. A regular tetrahedron is set up. The four solid waste materials of steel slag, slag, phosphorus slag, and carbide slag are used as four components. Each edge of the regular tetrahedron is set with three equal-distance intervals (grid degree m = 3), generating 20 enhanced simplex test lattice points (numbered: 1 - 20) with a uniform distribution. Each test lattice point is composed of the grading proportion combinations of the four solid waste materials, and all component proportions sum up to 100%; in addition, by setting 1 center point and 4 axis points as additional test lattice points to capture the non-linear effects inside the enhanced simplex regular tetrahedron, where the center point refers to the geometric center of the enhanced simplex regular tetrahedron, and the component ratio of the center point is the first quarter of the corresponding upper and lower limit ranges of the four solid waste materials (numbered: 21); the component ratio of the axis points is equal to the average value of the center point and the vertex (numbered: 22 - 25); at the same time, according to the reference percentage, 1 basic point (numbered: 26) is added, thus obtaining 26 enhanced simplex test lattice points. The component mass ratios of each lattice point are shown in Table 3.

[0082] Table 3

[0083]

[0084]

[0085] Next, a comparative test on the unconfined compressive strength of cement and solid waste-based binder curing aeolian sand under the same dosage is carried out. Among them, the binder dosage is defined as the ratio of the binder mass to the aeolian sand mass. Take the binder dosage = 11%, and the water content of the aeolian sand is 9% for all. The specific steps are as follows:

[0086] Grind the steel slag, slag, phosphorus slag, and carbide slag. The specific grinding parameters are: ball-to-material ratio = 1:1, rotation speed = 520 r / min; grinding time = 120 min to ensure that the particle size of each solid waste material after grinding is about 10 μm. Place the ground solid waste materials and aeolian sand in an oven and dry them for 6 hours at a constant temperature of 105°C to remove moisture;

[0087] According to the component content ratios of the above 26 test grid points, weigh the required solid waste materials, aeolian sand and water respectively. Put the weighed solid waste materials into the mixing pot of a planetary mixer and stir at a low speed until the color is uniform. Then, add the weighed aeolian sand all at once and continue to stir until the color of the mixture is uniform again;

[0088] Slowly add the weighed distilled water to the mixing pot. After continuing to stir at a low speed for 2 minutes, adjust the stirring speed to high speed and stir for 5 minutes to form a solidified aeolian sand mixture;

[0089] Use a funnel to pour the solidified aeolian sand mixture into a stainless-steel mold (diameter 50 mm × height 100 mm) pre-coated with lubricating oil. Pour it in three layers, and use a stainless-steel compactor to compact it continuously 15 times from the outside to the inside for each layer. Use a small knife to scrape the surface to ensure the continuity between layers. Three parallel test samples are prepared for each test grid point;

[0090] After filling, level the top surface and cover it with plastic wrap to prevent water loss. The specimens are cured with the mold indoors for 3 days and then demolded, and transferred to a constant temperature and humidity curing box at a temperature of 23°C ± 2°C and a relative humidity greater than 90% for continued curing until 28 days;

[0091] After the specimens reach the 28-day curing age, take the specimens out of the curing box and first check their integrity. After the inspection is intact, place the specimens on the bottom plate of an electronic universal testing machine for unconfined compressive strength (UCS) test and align them to prevent load eccentricity. Then start the test by starting the testing machine;

[0092] The unconfined compressive strength test applies a vertical load to the specimen by driving a connecting rod with a hydraulic jack. The load is collected in real time by a pressure sensor with a range of 10 kN (accuracy 0.001 kN), and a displacement sensor connected to the connecting rod synchronously records the deformation of the specimen. The test adopts a displacement control loading mode, and pre-presses at an initial loading rate of 0.1 mm / min. After the sensor shows a reading of 0.5 kN, further confirm the stable contact between the specimen and the sensor and the bottom plate, and adjust the loading rate to 0.08 mm / min to start the formal test loading stage. After an obvious peak appears in the load-displacement curve, when the force value drops by more than 30% of the maximum load, it is used as the failure criterion of the specimen and the test is terminated;

[0093] Each test grid point includes three parallel specimens, and the deviation of the unconfined compressive strength values of each group of three parallel specimens from the average value within the group does not exceed 15% of the average value. Therefore, the average value of the three parallel specimens is used as the unconfined compressive strength test value of each group. The unconfined compressive strength values of each test grid point in Table 3 and the comparison chart of their unconfined compressive strength with that of cement-solidified aeolian sand with the same dosage are as Figure 4 shown.

[0094] byFigure 4 It can be seen that when the mass ratio of steel slag:slag:phosphorus slag:calcium carbide slag is 5.0 wt%:35 wt%:20.0 wt%:40.0 wt% (grid number: 11), the unconfined compressive strength of the solidified aeolian sand is higher than that of the cement-solidified aeolian sand under the same dosage. Therefore, this mass ratio is the optimal mass ratio of the solid waste-based binder. In addition, when the mass ratio of steel slag:slag:phosphorus slag:calcium carbide slag is 5.0 wt%:26.67 wt%:28.33 wt%:40.0 wt% (grid number: 12), the unconfined compressive strength of the solidified aeolian sand is equal to that of the cement-solidified aeolian sand under the same dosage.

[0095] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0096] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A solid waste-based binder for solidifying aeolian sand in desert, characterized in that, The solid waste-based binder includes steel slag, slag, phosphorus slag, and carbide slag. Among them, the content of the steel slag is 5 wt%, the content of the slag is 26 wt% - 35 wt%, the content of the phosphorus slag is 20 wt% - 29 wt%, and the content of the carbide slag is 40 wt%.

2. The solid waste-based binder according to claim 1, wherein The content of the steel slag is 5 wt%, the content of the slag is 35 wt%, the content of the phosphorus slag is 20 wt%, and the content of the carbide slag is 40 wt%.

3. The solid waste-based binder according to claim 1, wherein The content of the steel slag is 5 wt%, the content of the slag is 26.67 wt%, the content of the phosphorus slag is 28.33 wt%, and the content of the carbide slag is 40 wt%.

4. The solid waste-based binder according to claim 1, wherein The content of silicon dioxide in the solid waste-based binder is 21.44% - 22.68%, the content of aluminum oxide is 6.27% - 7.32%, the content of iron oxide is 2.10% - 2.17%, and the content of calcium oxide is 51.81% - 52.29%.

5. The solid waste-based binder according to claim 1, characterized in that, The silica modulus of the solid waste-based binder is 2.25 - 2.70, the alumina modulus is 2.98 - 3.36, and the lime saturation factor is 0.65 - 0.

80.

6. A method for preparing the solid waste-based binder according to any one of claims 1-5, characterized in that, The method includes the following steps: Taking the content of Ca / Si / Al / Fe phase oxides in cement production as the control condition, determining the reference percentage of the mass composition of steel slag, slag, phosphorus slag, and carbide slag in the solid waste-based binder mixture; According to the reference percentage, using the mixture simplex lattice test method, setting the upper limit and lower limit of the content of steel slag, slag, phosphorus slag, and carbide slag. Among them, the upper limit increases by 8 - 20 percentage points based on the reference percentage, and the lower limit decreases by 3 - 14 percentage points based on the reference percentage; According to the upper limit and lower limit of the reference percentage of steel slag, slag, phosphorus slag, and carbide slag, using the enhanced simplex lattice test method, obtaining steel slag, slag, phosphorus slag, and carbide slag compositions with different percentage contents, respectively mixing the compositions with aeolian sand to obtain experimental groups, mixing cement and aeolian sand according to the same mass admixture ratio of the experimental groups to obtain a control group, respectively conducting unconfined compressive strength tests on the experimental groups and the control group, and screening out the target composition according to the test results to obtain the solid waste-based binder.

7. The method according to claim 6, wherein The calculation method of the reference percentage is as follows: Calculating the mass of steel slag, slag, phosphorus slag, and carbide slag through the formula group (I), namely m_steel slag, m_slag, m_phosphorus slag, m_carbide slag; A Si ×m 钢渣 +B Si ×m 矿渣 +C Si ×m 磷渣 +D Si ×m 电石渣 =W A Al ×m 钢渣 +B Al ×m 矿渣 +C Al ×m 磷渣 +D Al ×m 电石渣 =X A Fe ×m 钢渣 +B Fe ×m 矿渣 +C Fe ×m 磷渣 +D Fe ×m 电石渣 =Y A Ca ×m 钢渣 +B Ca ×m 矿渣 +C Ca ×m 磷渣 +D Ca ×m 电石渣 = Z formula set (I), According to the obtained mass of steel slag, slag, phosphorus slag, and carbide slag, calculating the mass percentage of steel slag, slag, phosphorus slag, and carbide slag in the solid waste-based binder respectively, so as to obtain the reference percentage; Among them, A Si , A Al , A Fe , A Ca respectively represent the mass content percentages of silicon dioxide, aluminum oxide, iron(III) oxide, and calcium oxide in the steel slag; B Si and B Al and B Fe and B Ca respectively represent the mass content percentages of silicon dioxide, aluminum oxide, iron(III) oxide, and calcium oxide in the slag; C Si 、C Al 、C Fe 、C Ca respectively represent the mass content percentages of silicon dioxide, aluminum oxide, iron(III) oxide, and calcium oxide in the phosphorus slag; D Si 、D Al 、D Fe 、D Ca respectively represent the mass content percentages of silicon dioxide, aluminum oxide, iron(III) oxide, and calcium oxide in carbide slag; W is the mass of silicon dioxide in 100 g of cement, X is the mass of aluminum oxide in 100 g of cement, Y is the mass of iron oxide in 100 g of cement, and Z is the mass of calcium oxide in 100 g of cement.

8. The method according to claim 7, wherein The average value of W is 20.59 g, the average value of X is 5.02 g, the average value of Y is 3.56 g, and the average value of Z is 63.56 g.

9. The method according to claim 6, wherein The specific steps of the enhanced simplex lattice test method are as follows: Set a regular tetrahedron, take four solid waste materials, namely steel slag, slag, phosphorus slag, and carbide slag, as four components, set each edge of the regular tetrahedron to three equal - value distances, generate 20 enhanced simplex test lattice points with uniform distribution. Each test lattice point is composed of the grading ratio combination of the four solid waste materials, and satisfies that the sum of all component ratios is 100%; By setting one center point and four axis points as additional test lattice points to capture the non - linear effect inside the enhanced simplex regular tetrahedron. Among them, the center point refers to the geometric center of the enhanced simplex regular tetrahedron, and the component ratio of the center point is the first quarter of the corresponding upper and lower limit ranges of the four solid waste materials; the component ratio of the axis point is equal to the average value of the center point and the vertex; According to the reference percentage, add one basic point, so as to obtain 26 enhanced simplex test lattice points.

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