Preparation process of saline soil modifier, curing material and application of curing material

Abstract

The invention discloses a preparation process of a saline soil modifier, a curing material and application of the curing material. The preparation process comprises the following steps: (1) providing absolute ethyl alcohol dispersion liquid of nano AlO; and (2) providing an alkaline solution of cyclic anhydride, adding the dispersion liquid, and stirring under a heating condition. And separating out a solid product, washing, and drying to obtain the solid stabilizer. (3) adding the solid stabilizer into polymethylhydrosiloxane, and stirring and reacting under a heating condition to obtain AlOamp; the invention relates to a polymethylhydrosiloxane pre-adsorption system. (4) forming the AlOamp on the substrate; and adding a chlorine salt solution into the polymethylhydrosiloxane pre-adsorption system, uniformly mixing to obtain a coarse mixed solution, carrying out ultrasonic dispersion treatment on the coarse mixed solution, and then carrying out emulsification treatment to obtain the modifier. The curing material disclosed by the invention has the characteristics of high efficiency, durability and low carbon, the strength and the stability of the side slope are remarkably improved, and the problems of poor durability, poor water erosion resistance and the like in a traditional protection method are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of soil solidification, in particular to a preparation process of a saline soil body modifier, a solidification material and application thereof. BACKGROUND

[0002] The information disclosed in this Background section is only for the purpose of increasing the understanding of the background of the present application and should not be taken as an acknowledgement or any form of suggestion that this information forms prior art with respect to the present application.

[0003] Rainfall is considered as the main natural factor and power source causing slope disaster. Because rainwater infiltration will increase the water content of soil, thereby reducing the shear strength and increasing the self-weight. Especially, the saline soil slope has high water sensitivity, and after encountering water, it will also cause the dissolution of easily soluble salt, resulting in the weakening of the connection between particles, and prone to disperse collapse, gully erosion, slope collapse and other damages under the conditions of rainfall, dry-wet cycle and the like.

[0004] At present, the commonly used protection means mainly includes: (1) engineering protection formed by adopting film bag concrete and other "external rigid shielding" structures. This structure only forms a layered structure of "external hard and internal loose" between the structure and the saline soil slope soil through mechanical pressure, lacking chemical or physical bonding. When the slope deforms, gaps are easily generated between the protection layer and the soil, and after rainwater seeps into the interior along the gaps, it will aggravate the collapse of the soil. In addition, due to the difficulty of the rigid protection layer itself to adapt to the swelling and shrinking deformation caused by the dry-wet cycle of the saline soil, cracks or overall falling are easily generated, resulting in poor durability. (2) ecological protection formed by planting plants. However, this way is in a weak protection state for a long time due to the long growth cycle of plants, and the slope is prone to be washed and landslides when encountering rainfall. In addition, there are few plants suitable for saline soil environment, and the dry climate is not conducive to growth, and the root system of the plants may aggravate the development of soil fissures, which may even reduce the stability of the slope. (3) traditional solidification agent prepared by using ordinary Portland cement and other cementitious materials. However, the production process of this kind of material has high energy consumption and large carbon emission, which conflicts with the current emission reduction and sustainable development concept. SUMMARY

[0005] The present application provides a preparation process of a saline soil body modifier, a solidification material and application thereof, which has the characteristics of high efficiency, durability and low carbon, significantly improves the strength and stability of the slope, and solves the problems of poor durability and water erosion resistance existing in the traditional protection method. Specifically, the technical scheme of the present application is as follows.

[0006] In a first aspect, the present application provides a preparation process of a saline soil body modifier, comprising the following steps: (1) providing a nano-Al2O3 ethanol dispersion solution, for standby use.

[0007] (2) providing an alkaline solution of cyclic anhydride, adding the dispersion liquid therein, and stirring under heating condition to react. After completion, the solid product is separated, washed, dried, and then the solid stabilizer is obtained.

[0008] (3) adding the solid stabilizer into polymethylhydrosiloxane, and stirring under heating condition to obtain an Al2O3 & polymethylhydrosiloxane pre-adsorption system, which is ready for use.

[0009] (4) adding a chlorate solution into the Al2O3 & polymethylhydrosiloxane pre-adsorption system, mixing to obtain a crude mixture, and then performing ultrasonic dispersion treatment and emulsification treatment to obtain the modifier.

[0010] Further, in step (1), the ratio of the nano-Al2O3 to anhydrous ethanol is 1-1.5 parts by weight: 6-7 parts by weight. Optionally, the particle size of the nano-Al2O3 is 50-60 nm.

[0011] Further, in step (2), the concentration of the alkaline solution is 0.1-0.2 mol / L. Optionally, the alkaline solution includes at least one of NaOH solution, KOH solution, etc. The cyclic anhydride (taking maleic anhydride as an example) undergoes ring opening under the action of the alkaline solution (taking sodium hydroxide as an example), as shown in the following formula (1).

[0012] Formula (1).

[0013] Further, in step (2), the dispersion liquid is added according to the ratio of the cyclic anhydride to nano-Al2O3 = 0.2-0.3 parts by weight: 1-2 parts by weight. Optionally, the cyclic anhydride includes at least one of maleic anhydride, citraconic anhydride, itaconic anhydride, etc.

[0014] Further, in step (2), the temperature of the heating is 55-65°C, and the reaction time is 5-6 h. In this process, the carboxyl group of the ring-opened cyclic anhydride and the hydroxyl group of the nano-Al2O3 undergo esterification to obtain a solid stabilizer / grafted nano-Al2O3 with double carboxyl groups, as shown in the following formula (2), taking the alkaline solution of step (2) as sodium hydroxide.

[0015] Formula (2).

[0016] Further, in step (2), the drying method includes at least one of freeze-drying, heating drying, etc. Optionally, the temperature of the heating drying is 55-65°C, and the time is 10-12 h.

[0017] Further, in step (3), the ratio of the polymethylhydrosiloxane to the solid stabilizer is 5-6 parts by weight: 1-1.5 parts by weight.

[0018] Further, in step (3), the temperature of the heating is 40-50℃, and the stirring time is 50-60 min. In this process, the polymethylhydrogen siloxane is a continuous phase, and the solid stabilizer is a dispersed phase. The combination of the two in advance ensures that after the addition of the chloride salt solution in step (4), there is no need to wait for the combination of the solid stabilizer and the polymethylhydrogen siloxane, which facilitates the rapid obtaining of the modifier which is uniformly dispersed and stable.

[0019] Further, in step (4), the ratio of the pre-adsorption system to the chloride salt solution is 6-7.5 parts by weight: 9-10 parts by weight. The present application utilizes the Cl ⁻ Compressing the double electric layer on the surface of the solid stabilizer particles can not only effectively prevent the agglomeration of the solid stabilizer, but also promote the adsorption of the solid stabilizer at the oil-water interface.

[0020] Further, in step (4), the chloride salt solution includes at least one of sodium chloride, potassium chloride, etc. Optionally, the mass fraction of the chloride salt solution is 0.15-0.25%.

[0021] Further, in step (4), the ultrasonic dispersion treatment time is 10-15 min. Optionally, the emulsification method includes high-speed shearing emulsification, etc.

[0022] In a second aspect, the present application provides a saline soil solidification material, which includes the following components in the following proportions: solid waste-based cementing material 6-9 parts by weight, alkali activator 3.6-5.4 parts by weight, gypsum 2.4-3.6 parts by weight, the modifier 4-8 parts by weight, and water 16-20 parts by weight.

[0023] Further, the solid waste-based cementing material includes at least one of fly ash, silica ash, mineral powder, steel slag, etc.

[0024] Further, the alkali activator includes at least one of carbide slag, calcium hydroxide, alkali slag, cement kiln dust, etc.

[0025] Further, the gypsum includes at least one of phosphogypsum, desulfurization gypsum, fluorogypsum, etc.

[0026] In a third aspect, the present application discloses the application of the above-mentioned solidification material in saline slope soil. Optionally, when applied, the solid waste-based cementing material, the alkali activator, and the gypsum are mixed first, then mixed with the saline slope soil, then the modifier and water are added, and then stirred uniformly. It should be noted that the dosage of the solidification material in the saline slope soil can be determined as needed, and the present application does not make specific limitations.

[0027] Compared with the prior art, the technical scheme of the present application has at least the following beneficial effects: Firstly, the solid stabilizer / nano Al2O3 grafted with double carboxyl groups obtained by modifying the cyclic anhydride after ring opening is emulsified with polymethylhydrogen siloxane to form an improver, and the solidified material formed by the improver and solid waste-based cementitious materials, etc. not only avoids the high energy consumption and high carbon emission caused by the use of traditional Portland cement, etc., realizes the resource recycling of industrial solid waste, but also forms a large amount of cementitious products under the action of alkali activator and gypsum to solidify the soil, quickly forms a protective effect, and overcomes the shortcomings of the above ecological protection methods. At the same time, the addition of the improver also significantly improves the strength and stability of the saline soil, solving the problems of poor durability and water erosion resistance of the soil in the traditional protection method. This is because: (1) The high water sensitivity of saline soil causes the formation of a water film on the surface of the soil particles after encountering water, which easily leads to a decrease in soil stability, dispersion and disintegration, gully erosion, slope toe collapse and other damage. The saline soil particles can be made water-resistant by the improver, avoiding the formation of a water film, and inhibiting the dispersion and disintegration of the soil from the source, thereby improving the long-term stability.

[0028] (2) When the solid waste-based cementitious material solidifies the soil, it mainly relies on the rigid cementation structure formed by the hardening of the cementitious components generated by the hydration reaction, but this structure has the problems of uneven internal pore distribution and hydrophilicity. Under dry-wet cycles, the rigid structure is prone to micro-cracks due to changes in pore water pressure, and after rainwater seeps in, it further weakens the internal connection by carrying the salt in the saline soil, leading to strength decay. The improver can effectively improve the water resistance of the rigid cementation structure as a whole, improve its stability, and prevent strength decay. Moreover, the solid stabilizer (i.e. nano Al2O3 grafted with double carboxyl groups) in the improver not only provides nucleation sites for the formation of ettringite with high crystalline water, promoting the hydration reaction of the solid waste-based cementitious material, but also slowly dissolves and releases Al³⁺ to directly supplement the Al element required for ettringite formation. This cementitious component can improve the mechanical strength of the soil and enhance its water stability after solidification.

[0029] (3) The ettringite has the characteristic of high crystalline water, which can utilize its strong water holding capacity to absorb the water discharged from the saline soil due to the dissolution of the easily soluble salt, reduce the erosion of free water to the soil structure, and improve the stability.

[0030] Secondly, the nano Al2O3 grafted with double carboxyl groups obtained by modifying the cyclic anhydride after ring opening is adsorbed on the surface of the emulsified polymethylhydrogen siloxane particles, effectively improving the stability of the improver, because the double carboxyl groups introduced on the surface of the nano Al2O3 particles can adsorb the Cl ⁻The high-density negative charge under compression can significantly enhance the electrostatic repulsion effect between particles, so as to inhibit the agglomeration between the nano-Al2O3 particles by charge repulsion in the high ionic environment of saline soil, and ensure that the emulsion is uniformly dispersed in the soil and cooperates with the solid waste-based cementitious material, alkali activator, and gypsum. In addition, the polymethyl hydrogen siloxane has abundant Si-H bonds, which can be combined with the -OH on the surface of the soil particles or the surface of the cementitious material to form a dense polysiloxane film after hydrolysis to Si-OH under the alkaline conditions provided by the solidified material, thereby enhancing the water stability of the soil. In addition, the Si-OH can also form a Si-O-Ca bridge with Ca²⁺ in the cementitious material, which also helps to enhance the water stability of the soil. BRIEF DESCRIPTION OF DRAWINGS

[0031] The accompanying drawings, which form a part of the present description, illustrate the present application and, together with the written description, serve to explain the application. In the drawings, which are not necessarily to scale, like elements are represented by like reference numerals.

[0032] Figure 1 A graph of the modifier sample prepared for the following Example 1.

[0033] Figure 2 A graph of the modifier sample prepared for the following Example 2.

[0034] Figure 3 A graph of the modifier sample prepared for the following Example 3. DETAILED DESCRIPTION

[0035] The application will be further described with reference to the following examples. It should be understood that these examples are intended to illustrate the application and are not intended to limit the scope of the application. The experimental methods in the following examples, unless otherwise specified, are generally carried out under conventional conditions or according to the manufacturer's recommendations.

[0036] Unless otherwise defined, all technical and scientific terms used in the application have the same meaning as commonly understood by one of ordinary skill in the art. The reagents or materials used in the application can be purchased through conventional channels, and unless otherwise specified, the reagents or materials used in the application are used according to conventional methods in the art or according to the product instructions.

[0037] In addition, any method and material similar or equivalent to those described can be used in the methods of the application. The technical solutions of the application are further described in conjunction with the drawings and specific examples in the specification.

[0038] Example 1: A preparation process of a saline soil improvement agent, comprising the following steps: (1) Nanometer Al203 with particle size of 50-60 nm was mixed with anhydrous ethanol at a ratio of 1.2 parts by weight:6.5 parts by weight, and then ultrasonic dispersion was carried out for 25 min at an ultrasonic power of 300 W, to obtain a dispersion liquid, which was ready for use.

[0039] (2) Cyclic anhydride (maleic anhydride) was dissolved in a 0.1 mol / L NaOH solution, and then added to the dispersion liquid at a ratio of cyclic anhydride:nanometer Al203 = 0.2 parts by weight:1.0 parts by weight. Then, the mixture was heated to 60°C and stirred for 5.5 hours. After completion, the solid product was separated by centrifugation (speed 10000 rpm, time 15 min), washed with deionized water until neutral, and then vacuum dried at 60°C for 11 hours, to obtain a solid stabilizer, which was ready for use.

[0040] (3) Polymethylhydrogen siloxane was mixed with the solid stabilizer at a ratio of 5 parts by weight:1 part by weight, and then heated and stirred at 40°C for 60 min, to obtain an Al203 & polymethylhydrogen siloxane pre-adsorption system, which was ready for use.

[0041] (4) A 0.2% sodium chloride solution was added to the Al203 & polymethylhydrogen siloxane pre-adsorption system at a ratio of 7 parts by weight:9.5 parts by weight, and then stirred for 2 min and ultrasonic dispersion treated for 15 min at an ultrasonic power of 300 W. Then, the mixture was emulsified by a high-speed shearing emulsifier (speed 12000 rpm, shearing time 10 min), to obtain the modifier, as shown in Figure 1

[0042] 2. A preparation method of a saline soil solidification material, comprising the following steps: (i) The following components were taken at the following ratios: fly ash 8 parts by weight, carbide slag 4.5 parts by weight, phosphogypsum 3 parts by weight, the modifier of the present embodiment 6 parts by weight, and water 18 parts by weight.

[0043] (ii) The fly ash, carbide slag, and phosphogypsum were first mixed uniformly, and then mixed with 100 parts by weight of saline slope soil and dry-mixed for 2 min. Then, the modifier and water were added, and the mixture was stirred uniformly to obtain the saline soil solidification material.

[0044] ​Performance test: The centrifugal stability and storage stability of the modifier prepared in this embodiment were tested according to the "Method for Testing the Properties of High Viscosity Emulsions in Surfactants and Evaluating the Emulsifying Ability thereof" (GB / T 11543-2008). The impermeability coefficient and 7d unconfined compressive strength of the saline soil solidified material prepared in this embodiment were tested according to the "Standard for Soil Test Methods" (GB / T 50123-2019). In addition, the water contact angle and strength retention rate of the saline soil solidified material after 5 dry-wet cycles were tested to measure the waterproofing ability and stability of the saline soil solidified material. The test results of the above indexes are shown in Table 1 below.

[0045] Table 1

[0046] Example 2: A preparation process of a saline soil improvement agent, comprising the following steps: (1) Nanometer Al2O3 with a particle size of 50-60 nm was mixed with anhydrous ethanol at a ratio of 1.0 part by weight: 6.0 parts by weight, and then ultrasonic dispersion was carried out for 25 min at an ultrasonic power of 300 W. After completion, a dispersion liquid was obtained for standby use.

[0047] (2) Cyclic anhydride (citraconic anhydride) was dissolved in a 0.1 mol / L NaOH solution, and then the dispersion liquid was added according to the ratio of cyclic anhydride to nanometer Al2O3 = 0.3 part by weight: 2.0 parts by weight. Then heated to 55°C and stirred for 6 hours. After completion, centrifugal separation (speed 10000 rpm, time 15 min) was carried out to obtain a solid product, which was washed with deionized water until neutral, and then vacuum dried at 65°C for 10 hours to obtain a solid stabilizer, which was standby used.

[0048] (3) Polymethylhydrogen siloxane was mixed with the solid stabilizer at a ratio of 6 parts by weight: 1.5 parts by weight, and then heated and stirred at 50°C for 50 min to obtain an Al2O3 & polymethylhydrogen siloxane pre-adsorption system, which was standby used.

[0049] (4) A 0.25% sodium chloride solution was added to the Al2O3 & polymethylhydrogen siloxane pre-adsorption system at a ratio of 7.5 parts by weight: 10 parts by weight, and then stirred for 2 min and ultrasonic dispersion treated for 15 min at an ultrasonic power of 300 W. Then emulsified by a high-speed shearing emulsifier (speed 12000 rpm, shearing time 15 min) to obtain the improvement agent, as shown in Figure 2 .

[0050] 2. A preparation method of a saline soil solidified material, comprising the following steps: (i) take the following proportions of components: fly ash 9 parts by weight, carbide slag 5.4 parts by weight, phosphogypsum 3.6 parts by weight, the modifier of the present embodiment 8 parts by weight, water 20 parts by weight.

[0051] (ii) first mix the fly ash, carbide slag, and phosphogypsum uniformly, then mix with 100 parts by weight of saline slope soil, dry mix for 2 min, then add the modifier and water, stir uniformly to obtain the saline soil body solidification material.

[0052] Performance test: the performances of the modifier and the saline soil body solidification material prepared in the present embodiment were tested by the same method as in Embodiment 1 above, and the results are shown in Table 2 below.

[0053] Table 2

[0054] Embodiment 3: A preparation process of a saline soil body modifier, comprising the following steps: (1) Mix nano-Al2O3 with a particle size of 50-60 nm and anhydrous ethanol at a ratio of 1.5 parts by weight: 7.0 parts by weight, then ultrasonic dispersion for 25 min, the ultrasonic power is 300 W, and the dispersion liquid is obtained after completion, which is ready for use.

[0055] (2) Dissolve the cyclic anhydride (itaconic anhydride) into a 0.2 mol / L KOH solution, then add the dispersion liquid according to the ratio of the cyclic anhydride to nano-Al2O3 = 0.25 parts by weight: 1.5 parts by weight. Then heat to 65°C and stir for 5 hours. After completion, centrifugal separation (speed 10000 rpm, time 15 min) to obtain the solid product, wash with deionized water until neutral, then vacuum dry at 55°C for 12 hours to obtain the solid stabilizer, which is ready for use.

[0056] (3) Mix polymethylhydrogen siloxane and the solid stabilizer at a ratio of 5.2 parts by weight: 1.3 parts by weight, then heat and stir at 45°C for 50 min to obtain an Al2O3 & polymethylhydrogen siloxane pre-adsorption system, which is ready for use.

[0057] (4) Add a 0.15% potassium chloride solution to the Al2O3 & polymethylhydrogen siloxane pre-adsorption system, the ratio of the two is 6 parts by weight: 9 parts by weight, stir for 2 min, then ultrasonic dispersion treatment for 10 min at an ultrasonic power of 350 W. Then emulsify by using a high-speed shearing emulsifier (speed 12000 rpm, shearing time 10 min) to obtain the modifier, as shown in Figure 3 .

[0058] 2. A preparation method of a saline soil body solidification material, comprising the following steps: (i) Take the following proportions of components: 6 parts by weight of silica ash, 3.6 parts by weight of calcium hydroxide, 2.4 parts by weight of phosphogypsum, 4 parts by weight of the modifier of the present embodiment, and 16 parts by weight of water.

[0059] (ii) First, mix the fly ash, carbide slag, and phosphogypsum uniformly, then mix with 100 parts by weight of saline slope soil, dry mix for 2 min, then add the modifier and water, stir uniformly to obtain the saline soil solidification material.

[0060] Performance test: The performance indicators of the modifier and the saline soil solidification material prepared in the present embodiment were tested by the same method as in Embodiment 1 above, and the results are shown in Table 3 below.

[0061] Table 3

[0062] Embodiment 4: A preparation process of a saline soil improvement agent, comprising the following steps: (1) Mix polymethylhydrogen siloxane and nano-Al2O3 with a particle size of 50-60 nm at a ratio of 5 parts by weight: 1 part by weight, then heat and stir at 40°C for 60 min to obtain an Al2O3 & polymethylhydrogen siloxane premix system, ready for use.

[0063] (2) Add a 0.2% sodium chloride solution to the Al2O3 & polymethylhydrogen siloxane premix system, at a ratio of 7 parts by weight: 9.5 parts by weight, stir for 2 min, then ultrasonic dispersion treatment for 15 min at an ultrasonic power of 300 W. Then emulsify with a high-speed shearing emulsifier (speed 12000 rpm, shearing time 10 min) to obtain the modifier.

[0064] 2. A preparation method of a saline soil solidification material, comprising the following steps: (i) Take the following proportions of components: 8 parts by weight of fly ash, 4.5 parts by weight of carbide slag, 3 parts by weight of phosphogypsum, 6 parts by weight of the modifier of the present embodiment, and 18 parts by weight of water.

[0065] (ii) First, mix the fly ash, carbide slag, and phosphogypsum uniformly, then mix with 100 parts by weight of saline slope soil, dry mix for 2 min, then add the modifier and water, stir uniformly to obtain the saline soil solidification material.

[0066] Performance test: The performance indicators of the modifier and the saline soil solidification material prepared in the present embodiment were tested by the same method as in Embodiment 1 above, and the results are shown in Table 4 below.

[0067] Table 4

[0068] Example 5: A preparation process of a saline soil improvement agent, comprising the following steps: mixing polymethylhydrogen siloxane, emulsifier (Tween-80) and deionized water according to the ratio of 7.5 parts by weight: 0.6 parts by weight: 10 parts by weight, and then emulsifying and treating by using a high-speed shearing emulsifier (rotating speed 12000 rpm, shearing time 15 min) to obtain an emulsion.

[0069] 2. A saline soil solidification material, comprising the following proportions of components: fly ash 9 parts by weight, carbide slag 5.4 parts by weight, phosphogypsum 3.6 parts by weight, the emulsion of the present embodiment 8 parts by weight, and water 20 parts by weight.

[0070] 3. The fly ash, carbide slag and phosphogypsum are first mixed uniformly, then mixed with 100 parts by weight of saline slope soil and dry-mixed for 2 min, then the improvement agent and water are added, and the saline soil solidification material is obtained after uniform stirring.

[0071] Performance test: The properties of the improvement agent and the saline soil solidification material prepared in the present embodiment are tested by the same method as in Example 1 above, and the results are shown in Table 5 below.

[0072] Table 5

[0073] Example 6: A preparation process of a saline soil improvement agent, comprising the following steps: (1) Nanometer Al2O3 with a particle size of 50-60 nm is mixed with anhydrous ethanol according to the ratio of 1.5 parts by weight: 7.0 parts by weight, and then ultrasonic dispersion is carried out for 25 min at an ultrasonic power of 300 W to obtain a dispersion liquid, which is ready for use.

[0074] (2) Cyclic anhydride (itaconic anhydride) is dissolved in a 0.2 mol / L KOH solution, and then the dispersion liquid is added according to the ratio of cyclic anhydride: nanometer Al2O3 = 0.25 parts by weight: 1.5 parts by weight. Then heated to 65°C and stirred for 5 hours. After completion, centrifugal separation (speed 10000 rpm, time 15 min) is carried out to obtain a solid product, which is washed with deionized water until neutral, and then vacuum dried at 55°C for 12 hours to obtain a solid stabilizer, which is ready for use.

[0075] (3) Polymethylhydrogen siloxane and the solid stabilizer are mixed according to the ratio of 5.2 parts by weight: 1.3 parts by weight, and then heated and stirred at 45°C for 50 min to obtain an Al2O3 & polymethylhydrogen siloxane pre-adsorption system, which is ready for use.

[0076] (4) The Al2O3 & polymethylhydrogen siloxane pre-adsorption system is emulsified by using a high-speed shearing emulsifier (rotating speed 12000 rpm, shearing time 10 min), and the modifier is obtained.

[0077] 2. A preparation method of a saline soil solidification material, comprising the following steps: (i) Take the following proportions of components: 6 parts by weight of silica fume, 3.6 parts by weight of calcium hydroxide, 2.4 parts by weight of phosphogypsum, 4 parts by weight of the modifier of the present embodiment, and 16 parts by weight of water.

[0078] (ii) First, mix the fly ash, calcium carbide slag, and phosphogypsum uniformly, then mix with 100 parts by weight of saline slope soil, dry mix for 2 min, then add the modifier and water, and stir uniformly to obtain the saline soil solidification material.

[0079] Performance test: The properties of the modifier and the saline soil solidification material prepared in the present embodiment are tested by the same method as in Embodiment 1, and the results are shown in Table 6.

[0080] Table 6

[0081] Embodiment 7: A preparation process of a saline soil improvement agent, comprising the following steps: (1) Mix nano-TiO2 with a particle size of 50-60 nm and anhydrous ethanol at a ratio of 1.2 parts by weight: 6.5 parts by weight, and then ultrasonic dispersion for 25 min at an ultrasonic power of 300 W to obtain a dispersion liquid, which is ready for use.

[0082] (2) Dissolve cyclic anhydride (maleic anhydride) into a 0.1 mol / L NaOH solution, then add the dispersion liquid according to the ratio of cyclic anhydride to nano-TiO2 = 0.2 parts by weight: 1.0 parts by weight. Then heat to 60°C and stir for 5.5 hours. After completion, centrifugal separation (speed 10000 rpm, time 15 min) to obtain solid product, wash with deionized water until neutral, and then vacuum dry at 60°C for 11 hours to obtain a solid stabilizer, which is ready for use.

[0083] (3) Mix polymethylhydrogen siloxane and the solid stabilizer at a ratio of 5 parts by weight: 1 part by weight, and then heat and stir at 40°C for 60 min to obtain a TiO2 & polymethylhydrogen siloxane pre-adsorption system, which is ready for use.

[0084] (4) In the TiO2& polymethyl hydrogen siloxane pre-adsorption system, 0.2% by mass of sodium chloride solution is added, the ratio of the two is 7 parts by weight:9.5 parts by weight, stirring for 2 min, then ultrasonic dispersion treatment for 15 min, ultrasonic power is 300 W. Then emulsification treatment is carried out by using a high-speed shearing emulsifier (rotating speed is 12000 rpm, shearing time is 10 min), thus the modified agent is obtained.

[0085] 2. A preparation method of a saline soil solidification material, comprising the following steps: (i) taking components in the following proportions: fly ash 8 parts by weight, carbide slag 4.5 parts by weight, phosphogypsum 3 parts by weight, the modified agent of the embodiment 6 parts by weight, water 18 parts by weight.

[0086] (ii) firstly, the fly ash, carbide slag and phosphogypsum are uniformly mixed, then mixed with 100 parts by weight of saline slope soil, dry mixing for 2 min, then the modified agent and water are added, uniformly stirring to obtain the saline soil solidification material.

[0087] Performance test: the performance indexes of the modified agent and the saline soil solidification material prepared in the embodiment are tested by using the same method as in the above embodiment 1, and the results are shown in Table 7.

[0088] Table 7

[0089] Embodiment 8: A preparation method of a saline soil solidification material, comprising the following steps: (i) taking components in the following proportions: silica ash 6 parts by weight, calcium hydroxide 3.6 parts by weight, phosphogypsum 2.4 parts by weight, acrylate emulsion 4 parts by weight, water 16 parts by weight.

[0090] (ii) firstly, the fly ash, carbide slag and phosphogypsum are uniformly mixed, then mixed with 100 parts by weight of saline slope soil, dry mixing for 2 min, then the modified agent and water are added, uniformly stirring to obtain the saline soil solidification material.

[0091] Performance test: the performance indexes of the modified agent and the saline soil solidification material prepared in the embodiment are tested by using the same method as in the above embodiment 1, and the results are shown in Table 8. It can be seen that: due to the influence of Na⁺ and Ca²⁺ in the saline soil on the acrylate emulsion, or the hydrolysis of the acrylate emulsion to form a cementation enrichment area in the soil, the uniformity is poor, and the hydration reaction of the cementing components is hindered, thus the performance of the soil is significantly decreased.

[0092] Table 8

[0093] The above merely provides preferred embodiments of the present application but not for limiting the present application. Although the present application has been described in detail with reference to the foregoing embodiments, the technical solutions recorded in the foregoing embodiments can still be modified or some technical features can be replaced equivalently by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A preparation process for a saline soil conditioner, characterized in that, Includes the following steps: (1) Provide an anhydrous ethanol dispersion of nano-Al2O3 for later use; (2) Provide an alkaline solution of a cyclic acid anhydride, add the dispersion to it, and stir the reaction under heating conditions; after completion, separate the solid product, wash it, and dry it to obtain a solid stabilizer for later use; (3) Add the solid stabilizer to polymethylhydrosiloxane and stir under heating conditions to obtain an Al2O3 & polymethylhydrosiloxane pre-adsorption system for later use; (4) Add chloride salt solution to the Al2O3 & polymethylhydrosiloxane pre-adsorption system, mix well to obtain a coarse mixture, and then perform emulsification treatment after ultrasonic dispersion to obtain the modifier.

2. The preparation process of the saline soil conditioner according to claim 1, characterized in that, In step (1), the ratio of nano-Al2O3 to anhydrous ethanol is 1~1.5 parts by weight: 6~7 parts by weight; optionally, the particle size of nano-Al2O3 is 50~60nm.

3. The preparation process of the saline soil conditioner according to claim 1, characterized in that, In step (2), the concentration of the alkaline solution is 0.1~0.2 mol / L; Optionally, the alkaline solution includes at least one of NaOH solution and KOH solution.

4. The preparation process of the saline soil conditioner according to claim 1, characterized in that, In step (2), the dispersion is added according to the ratio of cyclic anhydride to nano Al2O3 = 0.2~0.3 parts by weight: 1~2 parts by weight; Optionally, in step (2), the cyclic anhydride includes at least one of maleic anhydride, citraconic anhydride, and itaconic anhydride.

5. The preparation process of the saline soil conditioner according to claim 1, characterized in that, In step (2), the heating temperature is 55~65℃ and the reaction time is 5~6h; Optionally, in step (2), the drying method includes at least one of freeze drying and heat drying; Optionally, the heating and drying temperature is 55~65℃, and the time is 10~12h.

6. The preparation process of the saline soil conditioner according to claim 1, characterized in that, In step (3), the ratio of polymethylhydrosiloxane to solid stabilizer is 5-6 parts by weight: 1-1.5 parts by weight; Optionally, in step (3), the heating temperature is 40~50℃ and the stirring time is 50~60min.

7. The preparation process of the saline soil conditioner according to any one of claims 1-6, characterized in that, In step (4), the ratio of the pre-adsorption system to the chloride solution is 6-7.5 parts by weight: 9-10 parts by weight; Optionally, in step (4), the chloride salt solution includes at least one of sodium chloride and potassium chloride; Optionally, in step (4), the mass fraction of the chloride salt solution is 0.15~0.25%; Optionally, in step (4), the ultrasonic dispersion treatment time is 10~15 min.

8. A material for solidifying saline soil, characterized in that, The product comprises the following components in the following proportions: 6-9 parts by weight of solid waste-based cementitious material, 3.6-5.4 parts by weight of alkali activator, 2.4-3.6 parts by weight of gypsum, 4-8 parts by weight of the modifier obtained by the preparation process according to any one of claims 1-7, and 16-20 parts by weight of water.

9. The saline soil solidification material according to claim 8, characterized in that, The solid waste-based cementitious material includes at least one of the following: fly ash, silica fume, mineral powder, and steel slag; Optionally, the alkali activator includes at least one of the following: carbide slag, calcium hydroxide, alkali slag, and cement kiln ash; Optionally, the gypsum includes at least one of phosphogypsum, desulfurized gypsum, and fluorogypsum.

10. The application of the solidification material according to claim 8 or 9 in saline slope soil; optionally, when applying, the solid waste-based cementitious material, alkali activator, and gypsum are first mixed evenly, then mixed evenly with saline slope soil, and then the amendment and water are added and stirred evenly.

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