Soil improvement curing agent special for phosphogypsum curing and application of soil improvement curing agent

Abstract

The invention relates to a soil improvement curing agent special for ardealite curing and application, and belongs to the technical field of soil improvement, and the soil improvement curing agent comprises the following components based on 100 parts of total mass: 60-70 parts of an adhesive; 10 to 15 parts of a diluent; 2-3 parts of a coupling agent; 1-2 parts of a toughening agent; 0.1 to 0.5 part of a defoaming agent; 1-2 parts of an emulsifier; 1-2 parts of a water reducing agent; and the balance of deionized water. The soil stabilizer is an organic polymer composite soil stabilizer capable of forming a cross-linked network structure. The soil stabilizer disclosed by the invention has the characteristics of low pollution, good soil solidification performance, rich application scenes, good dispersion effect and the like, and the defoaming agent in the soil stabilizer can effectively eliminate bubbles generated in soil solidification, so that multiple pores of solidified soil are avoided, and the soil bonding and solidification effects are enhanced; the curing agent is especially suitable for a soil body with high water content and large particle size.

Description

Technical Field

[0001] The present invention belongs to the technical field of soil improvement, and specifically relates to a soil improvement curing agent specially used for phosphogypsum curing and its application, and especially relates to a soil improvement curing agent for untreated original phosphogypsum and its application. Background Art

[0002] The growth of crops is inseparable from phosphate fertilizers. There are many by-products in the production of phosphate fertilizers, and phosphogypsum is one of the most important. According to the wet process of producing phosphate fertilizers, the production of one ton of phosphoric acid will produce about five tons of phosphogypsum by-products, which is a huge output.

[0003] Phosphogypsum is a very important type of recyclable resource, and its main use as roadbed filler after solidification as mentioned in the prior art solution with patent publication number "CN118108478A" is particularly rapid. Soil solidifiers can quickly improve the soil properties of phosphogypsum and enable it to be used in various aspects. The solidification performance of soil solidifiers directly determines the use scenarios and added value of phosphogypsum. Therefore, the research, development, application and market promotion of phosphogypsum solidifiers have always been a hot topic in the industry.

[0004] At present, in order to make full use of phosphogypsum resources, the solidification of soil with high moisture content and large particle size is a difficult problem to solve with original phosphogypsum, which also puts higher requirements on the performance of the curing agent.

[0005] Therefore, it is necessary to develop a soil solidifier with good comprehensive performance and high efficiency in solidifying phosphogypsum. Summary of the invention

[0006] In order to address the defects in the prior art, the present invention proposes a soil improvement solidifying agent and application specifically used for phosphogypsum solidification, thereby obtaining a soil solidifying agent that can achieve efficient solidification of untreated original phosphogypsum after industrial production.

[0007] The present invention uses the following technical solutions.

[0008] A method for preparing a soil improvement curing agent specifically used for curing phosphogypsum, comprising:

[0009] Obtaining components used for preparation, including main ingredients of adhesive, diluent, coupling agent, toughening agent, defoaming agent, emulsifier, water reducing agent and deionized water;

[0010] In a four-necked flask, an adhesive is prepared by using the main ingredients of the adhesive, deionized water, a coupling agent, an emulsifier and a defoaming agent in the components;

[0011] Finally, the diluent, toughening agent and water reducing agent in the components are added to the four-necked flask, the temperature is raised to 70°C and stirred at a constant temperature for 2 hours, wherein the stirring speed is 100 rpm / min, and then the soil improvement curing agent specifically for phosphogypsum curing is obtained.

[0012] Furthermore, the components include the following components based on 100 parts by total mass: 60-70 parts of the main ingredients of the adhesive; 10-15 parts of the diluent; 2-3 parts of the coupling agent; 1-2 parts of the toughening agent; 0.1-0.5 parts of the defoaming agent; 1-2 parts of the emulsifier; 1-2 parts of the water reducing agent; and the balance is deionized water.

[0013] Furthermore, the main ingredients of the adhesive include polyisobutyl acrylate and lysine diisocyanate, wherein the mass percentage of polyisobutyl acrylate is 85wt% to 95wt%, and the mass percentage of lysine diisocyanate is 5wt% to 15wt%.

[0014] Furthermore, the adhesive is lysine diisocyanate modified polyisobutyl acrylate.

[0015] Furthermore, the lysine diisocyanate modified polyisobutyl acrylate is prepared by the following method: deionized water, emulsifier and defoamer in the pre-dissolved components are added into a four-necked flask and stirred evenly; polyisobutyl acrylate is added dropwise into the system at a rate of one drop per 50 seconds, the temperature is raised to 70°C to 90°C for reflux reaction after pre-emulsification, a coupling agent is added and the reaction is continued, and finally lysine diisocyanate is added and mixed and stirred for 30 minutes to obtain the lysine diisocyanate modified polyisobutyl acrylate.

[0016] Furthermore, the diluent is 1,6-hexanediol diacrylate, acetone or benzyl alcohol.

[0017] Furthermore, the coupling agent is γ-aminopropyltriethoxysilane or vinyltrichlorosilane.

[0018] Furthermore, the toughening agent is fumed silica.

[0019] Furthermore, the defoaming agent is polysiloxane, polyoxyethylene, or sodium alkyl glyceryl ether sulfonate.

[0020] Furthermore, the emulsifier is sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate or dodecylamine polyoxyethylene ether.

[0021] Furthermore, the water reducing agent is potassium lignin dodecylsulfonate or a polycarboxylic acid water reducing agent.

[0022] A soil improvement and solidifying agent specially used for phosphogypsum solidification, comprising:

[0023] The soil improvement curing agent is prepared by using the preparation method of the soil improvement curing agent specifically used for phosphogypsum curing.

[0024] An application of a soil improvement and solidifying agent, comprising:

[0025] The application of the soil improvement curing agent specially used for phosphogypsum curing in soil curing processing.

[0026] The beneficial effects of the present invention are that, compared with the prior art, the technical effects of the present invention include:

[0027] (1) The novel curing agent of the present invention has the characteristics of high soil strength, applicable to a wide range of soil types, good fluidity for easy construction, low pollution and environmental protection, etc. In addition, the defoaming agent in the curing agent can effectively eliminate the bubbles generated during soil curing, thereby avoiding the curing soil from having many pores and enhancing the soil bonding and curing effect.

[0028] (2) This solidifying agent is particularly suitable for soil solidification processes with large particle size and high water content. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic structural diagram of a soil improvement curing agent specially used for curing phosphogypsum in the present invention. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the present invention clearer, the following will be combined with the drawings in the embodiments of the present invention to clearly and completely express the technical solution of the present invention. The embodiments expressed in this application are only some embodiments of the present invention, not all embodiments. According to the spirit of the present invention, other embodiments obtained by ordinary technicians in this field without creative work are all within the protection scope of the present invention.

[0031] In order to make full use of phosphogypsum resources, high water content and large particle size are the difficulties that original phosphogypsum can solve, which also puts higher requirements on the performance of the curing agent. For phosphogypsum, the curing process mainly includes three aspects: soil strength, water stability and bubble porosity. In order to comprehensively and efficiently improve the performance of the soil, the composition of the curing agent must contain multiple components. For example, defoaming agents can effectively reduce the bubbles generated during soil mixing and curing, thereby improving the strength; water reducers can be evenly distributed on the surface of soil particles, effectively reducing the amount of external water, and greatly improving the water stability and strength of the mixed soil. At the same time, the cross-linked network structure formed by the adhesive can efficiently solidify the soil, thereby improving the overall strength of the soil and reducing the seepage of harmful elements such as fluorine and phosphorus.

[0032] like Figure 1 As shown, the preparation method of a soil improvement curing agent specifically used for phosphogypsum curing according to the present invention comprises:

[0033] Obtaining components used for preparation, including main ingredients of adhesive, diluent, coupling agent, toughening agent, defoaming agent, emulsifier, water reducing agent and deionized water;

[0034] In a four-necked flask, an adhesive is prepared by using the main ingredients of the adhesive, deionized water, a coupling agent, an emulsifier and a defoaming agent in the components;

[0035] Finally, the diluent, toughening agent and water reducing agent in the components are continued to be added into the four-necked flask, the temperature is raised to 70°C and the reaction is stirred at a constant temperature for 2 hours, wherein the stirring speed is 100 rpm / min, to obtain the soil improvement curing agent specifically for phosphogypsum curing, that is, the curing agent with a network cross-linking structure.

[0036] In a preferred but non-limiting embodiment of the present invention, the components include the following components based on 100 parts by total mass: 60-70 parts of the main ingredients of the adhesive; 10-15 parts of the diluent; 2-3 parts of the coupling agent; 1-2 parts of the toughening agent; 0.1-0.5 parts of the defoaming agent; 1-2 parts of the emulsifier; 1-2 parts of the water reducer; the balance is deionized water; the soil improvement curing agent specifically used for phosphogypsum curing is an organic polymer composite soil curing agent that can form a cross-linked network structure.

[0037] In a preferred but non-limiting embodiment of the present invention, the main ingredients of the adhesive include polyisobutyl acrylate and lysine diisocyanate, wherein the mass percentage of polyisobutyl acrylate is 85wt% to 95wt%, and the mass percentage of lysine diisocyanate is 5wt% to 15wt%.

[0038] In a preferred but non-limiting embodiment of the present invention, the adhesive is lysine diisocyanate modified polyisobutyl acrylate.

[0039] In a preferred but non-limiting embodiment of the present invention, the lysine diisocyanate-modified polyisobutyl acrylate is prepared by the following method: deionized water, emulsifier and defoamer in the pre-dissolved components are added into a four-necked flask and stirred evenly; dripped into the system at a rate of one drop per 50 seconds, heated to 70° C. to 90° C. for reflux reaction after pre-emulsification, continued to react after adding a coupling agent, and finally added lysine diisocyanate and blended and stirred for 30 minutes to obtain the lysine diisocyanate-modified polyisobutyl acrylate.

[0040] In a preferred but non-limiting embodiment of the present invention, the diluent is 1,6-hexanediol diacrylate, acetone or benzyl alcohol.

[0041] In a preferred but non-limiting embodiment of the present invention, the coupling agent is γ-aminopropyltriethoxysilane or vinyltrichlorosilane.

[0042] In a preferred but non-limiting embodiment of the present invention, the toughening agent is fumed silica.

[0043] In a preferred but non-limiting embodiment of the present invention, the defoaming agent is polysiloxane, polyoxyethylene, or sodium alkyl glyceryl ether sulfonate.

[0044] In a preferred but non-limiting embodiment of the present invention, the emulsifier is sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate or dodecylamine polyoxyethylene ether.

[0045] In a preferred but non-limiting embodiment of the present invention, the water reducer is potassium lignin dodecylsulfonate or a polycarboxylic acid water reducer.

[0046] The soil improvement curing agent specially used for curing phosphogypsum of the present invention comprises:

[0047] The soil improvement curing agent is prepared by using the preparation method of the soil improvement curing agent specifically used for phosphogypsum curing.

[0048] The application of a soil improvement and solidifying agent according to the present invention comprises:

[0049] The application of the soil improvement curing agent specially used for phosphogypsum curing in soil curing processing.

[0050] The principle of the present invention is as follows: the present invention technically utilizes lysine diisocyanate-modified polyisobutyl acrylate as an adhesive, which can form a polymer network structure through its own cross-linking reaction, and has a strong curing effect on the soil; at the same time, the molecular structure of the adhesive modified by lysine diisocyanate contains a large number of amino groups, which can form a strong intermolecular interaction with elements such as Si and P that exist in large quantities in the soil through a hydrogen-like bond effect, further improving the curing effect and reducing the seepage of harmful elements such as P and F; in addition, during the reaction process, it is combined with a water reducer to significantly consume the water content of the soil, reducing the adverse effect of the high water content of phosphogypsum on the compressive strength of the soil.

[0051] Beneficial effects: Compared with the prior art, the present invention has the following significant effects: (1) The new curing agent of the present invention has the characteristics of high soil strength, applicable to many soil types, good fluidity and convenient construction, low pollution and environmental protection, etc. In addition, the defoaming agent in the curing agent can effectively eliminate the bubbles generated during soil curing, thereby avoiding the curing soil from having many pores and enhancing the bonding and curing effect of the soil. (2) The curing agent is particularly suitable for the soil curing process with large particle size and high water content.

[0052] The following is a further detailed description of the method for preparing the soil improvement curing agent specifically used for curing phosphogypsum of the present invention through examples.

[0053] Example 1

[0054] The present embodiment provides a soil curing agent specifically for phosphogypsum curing, and its components are as follows, based on 100 parts by total mass: adhesive: 60 parts of lysine diisocyanate modified polyisobutyl acrylate; diluent: 10 parts of 1,6-hexanediol diacrylate; coupling agent: 3 parts of γ-aminopropyl triethoxysilane; toughening agent: 1 part of fumed silica; defoaming agent: 0.5 parts of polysiloxane; emulsifier: 2 parts of sodium dodecyl sulfate; water reducing agent: 2 parts of lignin potassium dodecyl sulfate, and the rest is deionized water.

[0055] Among them, the preparation method of the curing agent of the present invention is to add a pre-dissolved polyisobutyl acrylate solution, deionized water, an emulsifier and an appropriate amount of defoamer into a four-necked flask and stir evenly; add polyisobutyl acrylate dropwise, add it to the system at a rate of one drop per 50 seconds, heat it to 80°C for reflux reaction after pre-emulsification, continue to react after adding a coupling agent, then add lysine diisocyanate for blending and stirring, finally add a diluent, a coupling agent, a toughening agent and a water reducer, heat it to 70°C and stir the reaction at a constant temperature for 2 hours, wherein the stirring speed is 100rpm / min, and then obtain the curing agent with a network cross-linked structure. The lysine diisocyanate-modified polyisobutyl acrylate in the present embodiment has a lysine diisocyanate mass percentage of 15% and a polyisobutyl acrylate mass percentage of 85%.

[0056] After the materials are kept warm and stirred for a certain period of time according to the above steps, curing agent 1 is obtained.

[0057] Example 2

[0058] The present embodiment provides a soil curing agent specifically for phosphogypsum curing, which is composed of 100 parts by total mass: adhesive: 70 parts of lysine diisocyanate modified polyisobutyl acrylate; diluent: 15 parts of 1,6-hexanediol diacrylate; coupling agent: 2 parts of γ-aminopropyltriethoxysilane; toughening agent: 2 parts of fumed silica; defoaming agent: 0.1 parts of polysiloxane; emulsifier: 2 parts of sodium dodecyl sulfate; water reducing agent: 1 part of lignin potassium dodecyl sulfate, and the rest is deionized water.

[0059] In the lysine diisocyanate-modified polyisobutyl acrylate in this embodiment, the mass percentage of lysine diisocyanate is 5% by weight, and the mass percentage of polyisobutyl acrylate is 95% by weight.

[0060] After the materials are kept warm and stirred for a certain period of time according to the steps of Example 1, curing agent 2 is obtained.

[0061] Example 3

[0062] The present embodiment provides a soil curing agent specifically for phosphogypsum curing, which is composed of 100 parts by total mass: adhesive: 65 parts of lysine diisocyanate modified polyisobutyl acrylate; diluent: 15 parts of 1,6-hexanediol diacrylate; coupling agent: 2 parts of γ-aminopropyltriethoxysilane; toughening agent: 2 parts of fumed silica; defoaming agent: 0.1 parts of polysiloxane; emulsifier: 1 part of sodium dodecyl sulfate; water reducer: 1 part of lignin potassium dodecyl sulfate, and the rest is deionized water.

[0063] In the lysine diisocyanate-modified polyisobutyl acrylate in this embodiment, the mass percentage of lysine diisocyanate is 10% by weight, and the mass percentage of polyisobutyl acrylate is 90% by weight.

[0064] After the materials are kept warm and stirred for a certain period of time according to the steps of Example 1, curing agent 3 is obtained.

[0065] Comparative Example 1

[0066] The curing agent was prepared according to the formula of Example 1, except that the adhesive of lysine diisocyanate-modified polyisobutyl acrylate was not added in this comparative example. The prepared curing agent was recorded as comparative curing agent 1.

[0067] Comparative Example 2

[0068] The nanocomposite metal oxide with a core-shell structure is replaced by a mixture of non-nano-sized cerium oxide, titanium oxide and elemental gold. The high-efficiency soil solidifier with a network cross-linking structure is replaced by methyl methacrylate, butyl acrylate, initiator and emulsifier.

[0069] The cutting fluid was prepared according to the formula of Example 1, except that the lysine diisocyanate-modified polyisobutyl acrylate adhesive in Example 1 was replaced with a commercially available pure acrylic emulsion with a solid content of 47%. The prepared curing agent was recorded as comparative curing agent 2.

[0070] Taking the original phosphogypsum as the curing object, the curing agent of each embodiment above was subjected to a 7-day unconfined compressive strength test:

[0071] A strain-controlled unconfined compression instrument was used with a maximum load of 50KN. The compressive strength range of the test block was 0-10MPa. The instrument automatically measured after manual calibration. The test was performed according to the standard steps of the instrument. The test results are shown in the following table:

[0072] Table 1

[0073]

[0074] As can be seen from Table 1 above, the curing agent disclosed in the present invention contains an organic adhesive with a cross-linked network structure, which is uniformly dispersed in the curing agent, thus showing good curing performance, and can quickly form a bonding structure between soil and polymer during the curing process and maintenance process, effectively improving the strength of the soil, so that it can meet the strength requirements of the base material first-class highway. However, the comparative curing agent 1 does not contain any adhesive component, and a small amount of water reducer and defoamer do not significantly improve the strength of the soil, so the 7-day unconfined strength is less than 3MPa; although the comparative curing agent 2 is added with commercially available pure acrylic emulsion, its particle size is much larger than that of the lysine diisocyanate modified polyisobutyl acrylate adhesive, and it cannot be uniformly dispersed in the curing agent, so precipitation occurs, and it also cannot significantly improve the strength of the soil.

[0075] The curing agent prepared in the above embodiment and the comparative curing agent were tested for water resistance of phosphogypsum curing materials to characterize the water stability and other properties of the cured soil. The method is as follows:

[0076] The solidified soil with a curing age of 28 days after being cured by the curing agent (curing agent 1, 2, 3 and comparative curing agent 1, 2) was tested in accordance with GB / T50082-2009 "Test Method for Long-term Performance and Durability of Concrete". The test results are shown in Table 2 below:

[0077] Table 2

[0078]

[0079] It can be seen from the test data in Table 2 above that under the same test conditions, the test data of the cutting fluid configured according to the formula of Examples 1-3 are significantly better than those of the comparative samples, among which the result of curing agent 3 is the best, with a softening coefficient of up to 0.92 and a permeability coefficient of 4.66×10-8cm / s. All the data are significantly better than those of comparative curing agent 1 and comparative curing agent 2.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a soil improvement curing agent specifically for phosphogypsum curing, characterized in that: include: Obtaining components used for preparation, including main ingredients of adhesive, diluent, coupling agent, toughening agent, defoaming agent, emulsifier, water reducing agent and deionized water; In a four-necked flask, an adhesive is prepared by using the main ingredients of the adhesive, deionized water, a coupling agent, an emulsifier and a defoaming agent in the components; Finally, the diluent, toughening agent and water reducing agent in the components are added to the four-necked flask, the temperature is raised to 70° C. and the mixture is stirred at a constant temperature for 2 hours, wherein the stirring speed is 100 rpm / min, to obtain the soil improvement curing agent specifically used for phosphogypsum curing.

2. The method for preparing a soil improvement curing agent specifically for phosphogypsum curing according to claim 1, characterized in that: The components include the following components based on 100 parts by total weight: 60-70 parts of main ingredients of adhesive; 10-15 parts of diluent; 2-3 parts of coupling agent; 1-2 parts of toughening agent; 0.1-0.5 parts of defoaming agent; 1-2 parts of emulsifier; 1-2 parts of water reducing agent; and the balance is deionized water.

3. The method for preparing a soil improvement curing agent specifically for phosphogypsum curing according to claim 2, characterized in that: The main ingredients of the adhesive include polyisobutyl acrylate and lysine diisocyanate, wherein the mass percentage of the polyisobutyl acrylate is 85wt%-95wt%, and the mass percentage of the lysine diisocyanate is 5wt%-15wt%.

4. The method for preparing a soil improvement curing agent specifically for phosphogypsum curing according to claim 3, characterized in that: The adhesive is lysine diisocyanate modified polyisobutyl acrylate.

5. The method for preparing a soil improvement curing agent specifically for phosphogypsum curing according to claim 4, characterized in that: The lysine diisocyanate modified polyisobutyl acrylate is prepared by the following method: adding deionized water, an emulsifier and a defoamer which are pre-dissolved in the components into a four-necked flask and stirring evenly; dropping polyisobutyl acrylate into the system at a speed of one drop per 50 seconds, heating to 70°C to 90°C for reflux reaction after pre-emulsification, adding a coupling agent and continuing the reaction, and finally adding lysine diisocyanate and blending and stirring for 30 minutes to obtain the lysine diisocyanate modified polyisobutyl acrylate.

6. The method for preparing a soil improvement curing agent specifically for phosphogypsum curing according to claim 5, characterized in that: The diluent is 1,6-hexanediol diacrylate, acetone or benzyl alcohol; The coupling agent is gamma-aminopropyltriethoxysilane or vinyltrichlorosilane.

7. The method for preparing a soil improvement curing agent specifically for phosphogypsum curing according to claim 6, characterized in that: The toughening agent is fumed silica; The defoaming agent is polysiloxane, polyoxyethylene, or sodium alkyl glyceryl ether sulfonate.

8. The method for preparing a soil improvement curing agent specifically for phosphogypsum curing according to claim 7, characterized in that: The emulsifier is sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate or dodecylamine polyoxyethylene ether; The water reducing agent is potassium lignin dodecylsulfonate or a polycarboxylic acid water reducing agent.

9. A soil improvement and curing agent specially used for phosphogypsum curing, characterized in that: include: A soil improvement and curing agent prepared by the method for preparing a soil improvement and curing agent specifically for curing phosphogypsum according to any one of claims 1 to 8.

10. An application of a soil improvement and solidifying agent, characterized in that: include: The use of the soil improvement and curing agent specifically for phosphogypsum curing as described in claim 9 in soil curing processing.

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