Geopolymer grouting material and preparation method thereof

Abstract

The present application relates to a kind of geopolymer grouting material and preparation method thereof, it relates to grouting material technical field, with weight parts, the geopolymer grouting material includes following raw materials: red mud 20~30 parts, fly ash 7~15 parts and alkali activator 50~65 parts;The alkali activator is by the weight ratio of (15~19) :(7~11) silica ash-based solution and modified water glass solution composition.This application is activated and modified to red mud by adopting oxygen-rich microwave plasma process, while cooperating with the alkali activator of the specific proportion of silica ash-based solution and modified water glass solution composition, significantly improve the coagulation rate and mechanical strength etc. of red mud-fly ash geopolymer performance, meet the use requirement of rapid setting of grouting material, make up the deficiency of existing red mud-fly ash geopolymer grouting material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of grouting materials, in particular to a geopolymer grouting material and a preparation method thereof. BACKGROUND

[0002] In today's field of construction and civil engineering, grouting materials, as an important engineering material, are widely used in foundation reinforcement, tunnel support, dam seepage prevention and concrete structure repair, etc. Traditional grouting materials such as cement-based grouting materials, although mature in technology and widely used, have problems such as high energy consumption, large resource consumption and environmental pollution. With the increasing global awareness of sustainable development and environmental protection, the development of new green and high-performance grouting materials has become a hot topic in the industry.

[0003] In recent years, geopolymer, as a new type of inorganic cementitious material, can form a high molecular compound with a three-dimensional network structure by activating silicate minerals, and exhibit certain mechanical properties and durability. The raw materials are mainly industrial solid wastes, which have the characteristics of low carbon and environmental protection, low price and high performance, and are considered as one of the most promising new green cementitious materials in the 21st century. The raw materials of geopolymer are widely available, among which red mud and fly ash, as two major industrial wastes, contain abundant silicate minerals with potential cementitious activity, and can be used as raw materials for preparing geopolymer grouting materials. However, the activity of red mud and fly ash is low, and when they are directly used to prepare geopolymer grouting materials, the red mud-fly ash geopolymer grouting material has problems such as slow setting rate and insufficient mechanical strength, which is difficult to meet the requirements of practical engineering application. Therefore, exploring the transformation of industrial wastes such as red mud and fly ash into high-performance grouting materials not only helps to solve environmental problems, but also realizes the recycling of resources, which has important economic and environmental significance. SUMMARY

[0004] To solve the above problems, the present application provides a geopolymer grouting material and a preparation method thereof.

[0005] In the first aspect, the present application provides a geopolymer grouting material, which comprises the following raw materials in parts by weight:

[0006] 20-30 parts of red mud, 7-15 parts of fly ash and 50-65 parts of alkali activator;

[0007] The alkali activator is composed of a silica ash-based solution and a modified water glass solution in a weight ratio of (15-19):(7-11).

[0008] Further, the geopolymer grouting material comprises the following raw materials in parts by weight:

[0009] 24 parts red mud, 10 parts fly ash, and 60 parts alkali activator.

[0010] Furthermore, the weight ratio of the red mud to the fly ash is 2.4:1.

[0011] Furthermore, the preparation of the silica fume-based solution includes the following process:

[0012] A potassium hydroxide solution of 40-50% by weight and silica fume are mixed by stirring at a weight ratio of (3-7):(1-3) to obtain the silica fume-based solution.

[0013] Furthermore, the preparation of the modified water glass solution includes the following process:

[0014] The modified water glass solution is obtained by stirring and mixing a water glass solution with a modulus of 2.2-2.5 and polyvinyl alcohol with a degree of polymerization of <2000 at a weight ratio of (10-15):(3-7).

[0015] Furthermore, the polyvinyl alcohol includes at least one of polyvinyl alcohol 1799 and polyvinyl alcohol 1788.

[0016] Furthermore, the red mud includes at least one of sintered red mud and Bayer red mud; the fly ash includes secondary fly ash.

[0017] Secondly, the present invention provides a method for preparing the geopolymer grouting material according to any one of the first aspects, the method comprising the following steps:

[0018] Preparation of alkaline activators;

[0019] The red mud was crushed and sieved, and then subjected to oxygen-enriched microwave plasma treatment to obtain modified red mud.

[0020] The modified red mud, fly ash, and alkali activator are stirred and mixed to obtain the geopolymer grouting material.

[0021] Furthermore, the oxygen-rich microwave plasma treatment step includes the following process:

[0022] Red mud with a particle size of 300-500 mesh after being crushed and sieved was placed in a microwave plasma treatment instrument. A mixed gas consisting of oxygen and argon with a volume ratio of 8:1 was used as the working medium. Under the conditions of microwave power set to 750-850W and gas flow maintained at 100-120mL / min, glow discharge treatment was performed for 2-5 minutes. Oxygen was then continuously introduced for 10-15 minutes to obtain the modified red mud.

[0023] The technical solutions provided in the embodiments of the present invention have at least the following advantages compared with the prior art:

[0024] The embodiment of the present application provides a geopolymer grouting material and a preparation method thereof, in particular to a red mud-fly ash geopolymer grouting material. In one aspect, the red mud is modified by using the oxygen-rich microwave plasma process, which promotes the recrystallization of the mineral phase in the red mud and the optimization of the microstructure, forms more active surface sites, thereby significantly improving the reaction activity of the red mud. The red mud after the oxygen-rich microwave plasma treatment has enhanced activity, and the reaction with the alkali activator is more sufficient and rapid, which accelerates the formation of the geopolymer. Meanwhile, the alkali activator composed of the silica fume-based solution and the modified water glass solution in a specific ratio optimizes the microstructure of the geopolymer and improves the overall performance of the material. The double-acting mechanism significantly improves the condensation rate and mechanical strength of the red mud-fly ash geopolymer, meets the use requirements of the rapid-setting grouting material, and makes up for the deficiencies of the existing red mud-fly ash geopolymer grouting material.

[0025] Therefore, the present application realizes the significant improvement of the performance of the red mud-fly ash geopolymer grouting material through the synergistic effect of the oxygen-rich microwave plasma treatment and the special alkali activator, and also provides a new way for the resource utilization of industrial waste such as red mud, which has significant environmental and economic benefits. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme of the present application will be described clearly and completely below in combination with the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0027] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present application can be purchased from the market or prepared by existing methods.

[0028] In a first aspect, the present application provides a geopolymer grouting material, which comprises the following raw materials in parts by weight:

[0029] The red mud is 20-30 parts, the fly ash is 7-15 parts, and the alkali activator is 50-65 parts.

[0030] The alkali activator is composed of a silica fume-based solution and a modified water glass solution in a weight ratio of (15-19):(7-11).

[0031] The embodiment of the present application provides a geopolymer grouting material, in particular, a red mud-fly ash geopolymer grouting material. In one aspect, the red mud is modified by using the oxygen-rich microwave plasma process, which promotes the recrystallization of the mineral phase in the red mud and the optimization of the microstructure, forms more active surface sites, and thus significantly improves the reaction activity of the red mud. The red mud after the oxygen-rich microwave plasma treatment has enhanced activity, and the reaction with the alkali activator is more sufficient and rapid, which accelerates the formation of the geopolymer. Meanwhile, the alkali activator is composed of a silica fume-based solution and a modified water glass solution in a specific proportion. By adjusting the Si / Al ratio in the solution, the composition of the alkali activator optimizes the microstructure of the geopolymer and improves the overall performance of the material. This dual mechanism significantly improves the setting rate and mechanical strength of the red mud-fly ash geopolymer, meets the use requirements of the rapid setting of the grouting material, and makes up for the deficiencies of the existing red mud-fly ash geopolymer grouting material.

[0032] In some embodiments, the geopolymer grouting material includes the following raw materials in parts by weight:

[0033] The red mud is 24 parts, the fly ash is 10 parts, and the alkali activator is 60 parts.

[0034] In some embodiments, the weight ratio of the red mud to the fly ash is 2.4:1.

[0035] In some embodiments, the alkali activator is composed of a silica fume-based solution and a modified water glass solution in a weight ratio of 17:9.

[0036] In some embodiments, the preparation of the silica fume-based solution includes the following process:

[0037] The potassium hydroxide solution with a weight percentage of 40-50% and the silica fume are stirred and mixed in a weight ratio of (3-7):(1-3) to obtain the silica fume-based solution. Preferably, the weight ratio of the potassium hydroxide solution to the silica fume is 5:2.

[0038] In some embodiments, the preparation of the modified water glass solution includes the following process:

[0039] The water glass solution with a modulus of 2.2-2.5 and the polyvinyl alcohol with a degree of polymerization of <2000 are stirred and mixed in a weight ratio of (10-15):(3-7) to obtain the modified water glass solution. Preferably, the weight ratio of the water glass solution to the polyvinyl alcohol is 13:5.

[0040] In some embodiments, the polyvinyl alcohol includes at least one of polyvinyl alcohol 1799 and polyvinyl alcohol 1788.

[0041] In some specific embodiments, the water glass solution can be directly used as a commercially available product with a corresponding modulus, or self-made according to the modulus adjustment method of the water glass solution disclosed in CN 110467187A, to obtain a water glass solution with a modulus of 2.2-2.5.

[0042] In some specific embodiments, the red mud comprises at least one of sintering process red mud and Bayer process red mud, preferably sintering process red mud; and the fly ash comprises secondary fly ash.

[0043] It should be noted that, unless otherwise specified or described, the component raw materials involved in the geopolymer grouting material provided by the embodiments of the present application, such as red mud, fly ash, potassium hydroxide solution, silica ash, polyvinyl alcohol, etc., can be directly used as commercially available products or self-made according to the methods disclosed in the prior art, and will not be repeated here.

[0044] In a second aspect, based on the overall inventive concept, the present application provides a preparation method of the geopolymer grouting material according to any one of the first aspect, the preparation method comprising the following steps:

[0045] preparing an alkali activator;

[0046] crushing and sieving the red mud, and then performing oxygen-rich microwave plasma treatment to obtain modified red mud;

[0047] stirring and mixing the modified red mud, fly ash and the alkali activator to obtain the geopolymer grouting material.

[0048] The preparation method of the geopolymer grouting material provided by the embodiments of the present application is based on the geopolymer grouting material according to any one of the first aspect, and therefore at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here.

[0049] In some specific embodiments, the step of oxygen-rich microwave plasma treatment comprises the following process:

[0050] The crushed and sieved red mud with a particle size of 300-500 mesh is placed in a microwave plasma treatment instrument, a mixed gas composed of oxygen and argon with a volume ratio of 8:1 is used as a working medium, glow discharge treatment is performed for 2-5 minutes under the conditions that the microwave power is set to 750-850 W and the gas inlet amount is maintained at 100-120 mL / min, and then oxygen is continuously introduced for 10-15 minutes to obtain the modified red mud.

[0051] It should be noted that, unless otherwise specified or described, the operation steps involved in the preparation method of the geopolymer grouting material provided by the embodiments of the present application can be performed according to the preparation processes disclosed in the prior art or using existing equipment, and will not be repeated here.

[0052] The application will be further described in conjunction with specific examples. It should be understood that these examples are only used to illustrate the application and not used to limit the scope of the application. The experimental methods in the following examples without specific conditions are generally determined according to national standards. If there is no corresponding national standard, it is determined according to the general international standard, the conventional condition, or the condition suggested by the manufacturer.

[0053] Example 1

[0054] This example provides a geopolymer grouting material, which comprises the following raw materials in parts by weight:

[0055] 24 parts of red mud, 10 parts of fly ash and 60 parts of alkali activator;

[0056] The red mud is sintered red mud;

[0057] The fly ash is secondary fly ash;

[0058] The alkali activator is composed of a silica ash-based solution and a modified water glass solution in a weight ratio of 17:9;

[0059] The preparation of the silica ash-based solution comprises the following process: a potassium hydroxide solution with a weight percentage of 45% and silica ash are stirred and mixed in a weight ratio of 5:2 to obtain the silica ash-based solution;

[0060] The preparation of the modified water glass solution comprises the following process: a water glass solution with a modulus of 2.4 and polyvinyl alcohol 1788 are stirred and mixed in a weight ratio of 13:5 to obtain the modified water glass solution.

[0061] The preparation method of the above geopolymer grouting material comprises the following steps:

[0062] Step (1): preparing an alkali activator;

[0063] Step (2): crushing and sieving the red mud to obtain red mud with a particle size of 400 mesh; then placing the crushed and sieved red mud with a particle size of 400 mesh in a microwave plasma treatment instrument, using a mixed gas composed of oxygen and argon in a volume ratio of 8:1 as the working medium, carrying out glow discharge treatment under the conditions of microwave power set to 800 W and gas inlet amount maintained at 115 mL / min for 3.5 minutes, and then continuously introducing oxygen for 10 minutes to obtain the modified red mud;

[0064] Step (3): stirring and mixing the modified red mud, fly ash and the alkali activator to obtain the geopolymer grouting material.

[0065] Example 2

[0066] The example provides a geopolymer grouting material, the geopolymer grouting material comprises the following raw materials in parts by weight:

[0067] 20 parts of red mud, 7 parts of fly ash and 50 parts of alkali activator;

[0068] The red mud is sintered red mud;

[0069] The fly ash is secondary fly ash;

[0070] The alkali activator is composed of a silica ash-based solution and a modified water glass solution in a weight ratio of 15:7;

[0071] The preparation of the silica ash-based solution comprises the following process: stirring and mixing a potassium hydroxide solution with a weight percentage of 40% and silica ash in a weight ratio of 7:3 to obtain the silica ash-based solution;

[0072] The preparation of the modified water glass solution comprises the following process: stirring and mixing a water glass solution with a modulus of 2.2 and polyvinyl alcohol 1799 in a weight ratio of 10:3 to obtain the modified water glass solution.

[0073] The preparation method of the above geopolymer grouting material comprises the following steps:

[0074] Step (1): preparing an alkali activator;

[0075] Step (2): crushing and sieving the red mud to obtain red mud with a particle size of 400 mesh; then placing the crushed and sieved red mud with a particle size of 400 mesh in a microwave plasma treatment instrument, using a mixed gas composed of oxygen and argon in a volume ratio of 8:1 as the working medium, carrying out glow discharge treatment under the conditions of microwave power set to 750 W and gas inlet amount maintained at 100 mL / min for 5 minutes, and then continuously introducing oxygen for 15 minutes to obtain the modified red mud;

[0076] Step (3): stirring and mixing the modified red mud, fly ash and the alkali activator to obtain the geopolymer grouting material.

[0077] Example 3

[0078] The example provides a geopolymer grouting material, the geopolymer grouting material comprises the following raw materials in parts by weight:

[0079] 30 parts of red mud, 15 parts of fly ash and 65 parts of alkali activator;

[0080] The red mud is sintered red mud;

[0081] The fly ash is secondary fly ash;

[0082] The alkali activator is composed of a silica ash-based solution and a modified water glass solution with a weight ratio of 19:11;

[0083] The preparation of the silica ash-based solution comprises the following process: stirring and mixing a 50% potassium hydroxide solution and silica ash with a weight ratio of 3:1 to obtain the silica ash-based solution;

[0084] The preparation of the modified water glass solution comprises the following process: stirring and mixing a water glass solution with a modulus of 2.5 and polyvinyl alcohol 1799 with a weight ratio of 15:7 to obtain the modified water glass solution.

[0085] The preparation method of the above-mentioned geopolymer grouting material comprises the following steps:

[0086] Step (1): preparing an alkali activator;

[0087] Step (2): crushing and sieving the red mud to obtain red mud with a particle size of 400 mesh; then placing the crushed and sieved red mud with a particle size of 400 mesh in a microwave plasma treatment instrument, using a mixed gas composed of oxygen and argon with a volume ratio of 8:1 as the working medium, carrying out glow discharge treatment for 2 minutes under the conditions of microwave power set to 850 W and gas inlet amount maintained at 120 mL / min, and then continuously introducing oxygen for 10 minutes to obtain the modified red mud;

[0088] Step (3): stirring and mixing the modified red mud, fly ash and the alkali activator to obtain the geopolymer grouting material.

[0089] Comparative Example 1

[0090] This example provides a geopolymer grouting material and a preparation method thereof, which is different from Example 1 only in that the red mud is not subjected to the oxygen-enriched plasma treatment in step (2); the rest of the steps and parameters are the same.

[0091] This example provides a geopolymer grouting material, which comprises the following raw materials in parts by weight:

[0092] 24 parts of red mud, 10 parts of fly ash and 60 parts of alkali activator;

[0093] The red mud is sintered red mud;

[0094] The fly ash is secondary fly ash;

[0095] The alkali activator is composed of a silica ash-based solution and a modified water glass solution with a weight ratio of 17:9;

[0096] The preparation of the silica ash-based solution includes the following process: stirring and mixing a 45wt% potassium hydroxide solution and silica ash at a weight ratio of 5:2 to obtain the silica ash-based solution.

[0097] The preparation of the modified water glass solution includes the following process: stirring and mixing a water glass solution with a modulus of 2.4 and polyvinyl alcohol 1788 at a weight ratio of 13:5 to obtain the modified water glass solution.

[0098] The preparation method of the above-mentioned geopolymer grouting material includes the following steps:

[0099] Step (1): preparing an alkali activator;

[0100] Step (2): stirring and mixing red mud, fly ash and the alkali activator to obtain the geopolymer grouting material.

[0101] Comparative Example 2

[0102] This example provides a geopolymer grouting material and a preparation method thereof, which is only different from Example 1 in that the alkali activator is only composed of a silica ash-based solution; the remaining steps and parameters are the same.

[0103] This example provides a geopolymer grouting material, which includes the following raw materials in parts by weight:

[0104] 24 parts of red mud, 10 parts of fly ash and 60 parts of an alkali activator;

[0105] The red mud is sintered red mud;

[0106] The fly ash is secondary fly ash;

[0107] The alkali activator is a silica ash-based solution;

[0108] The preparation of the silica ash-based solution includes the following process: stirring and mixing a 45wt% potassium hydroxide solution and silica ash at a weight ratio of 5:2 to obtain the silica ash-based solution.

[0109] The preparation method of the above-mentioned geopolymer grouting material includes the following steps:

[0110] Step (1): preparing an alkali activator;

[0111] Step (2): The red mud was crushed and sieved to obtain red mud with a particle size of 400 mesh; then the red mud with a particle size of 400 mesh after crushing and sieving was placed in a microwave plasma treatment instrument, a mixed gas composed of oxygen and argon with a volume ratio of 8:1 was used as the working medium, and the microwave power was set to 800 W, the gas inlet amount was maintained at 115 mL / min, and the glow discharge treatment was carried out for 3.5 minutes, and then the oxygen was continuously introduced for 10 minutes to obtain the modified red mud;

[0112] Step (3): The modified red mud, fly ash and the alkali activator were stirred and mixed to obtain the geopolymer grouting material.

[0113] Comparative Example 3

[0114] This example provides a geopolymer grouting material and a preparation method thereof, which is different from Example 1 only in that the weight fraction of the red mud is adjusted to 10 parts, and the weight fraction of the fly ash is adjusted to 24 parts; the rest of the steps and parameters are the same.

[0115] This example provides a geopolymer grouting material, which comprises the following raw materials in weight fractions:

[0116] 10 parts of red mud, 24 parts of fly ash and 60 parts of alkali activator;

[0117] The red mud is sintered red mud;

[0118] The fly ash is secondary fly ash;

[0119] The alkali activator is composed of a silica ash-based solution and a modified water glass solution with a weight ratio of 17:9;

[0120] The preparation of the silica ash-based solution includes the following process: a 45% by weight potassium hydroxide solution and silica ash are stirred and mixed at a weight ratio of 5:2 to obtain the silica ash-based solution;

[0121] The preparation of the modified water glass solution includes the following process: a water glass solution with a modulus of 2.4 and polyvinyl alcohol 1788 are stirred and mixed at a weight ratio of 13:5 to obtain the modified water glass solution.

[0122] The preparation method of the above geopolymer grouting material includes the following steps:

[0123] Step (1): Prepare the alkali activator;

[0124] Step (2): the red mud is crushed and sieved to obtain red mud with a particle size of 400 mesh; then the crushed and sieved red mud with a particle size of 400 mesh is placed in a microwave plasma treatment instrument, a mixed gas composed of oxygen and argon with a volume ratio of 8:1 is used as a working medium, and the microwave power is set to 800 W, the gas inlet amount is maintained at 115 mL / min, and the glow discharge treatment is carried out for 3.5 minutes, and then the oxygen is continuously introduced for 10 minutes to obtain the modified red mud;

[0125] Step (3): the modified red mud, fly ash and the alkali activator are stirred and mixed to obtain the geopolymer grouting material.

[0126] Test example

[0127] In this example, the geopolymer grouting materials prepared in Examples 1-3 and Comparative Examples 1-3 are tested for performance according to the test method disclosed in the prior art. The initial setting time and final setting time are tested on part of the mixed slurry during preparation, and the remaining mixed material is made into a standard test mold, which is placed flat for 24 hours to release the mold at 25-30℃, and the compressive strength is tested after 28 days of curing. The results are shown in Table 1.

[0128] Table 1

[0129]

[0130]

[0131] As can be seen from Table 1, compared with the comparative examples, the geopolymer grouting material provided in the examples of the present application has the characteristics of fast setting rate and high compressive strength, which can meet the use requirements of the rapid setting of grouting materials.

[0132] In summary, the present application provides a geopolymer grouting material and a preparation method thereof. The present application activates and modifies the red mud by using the oxygen-enriched microwave plasma process, and at the same time, uses a specific proportion of the alkali activator composed of the silica ash-based solution and the modified water glass solution, which significantly improves the setting rate and mechanical strength of the red mud-fly ash geopolymer, meets the use requirements of the rapid setting of grouting materials, and makes up for the shortcomings of the existing red mud-fly ash geopolymer grouting material.

[0133] The above is only a specific embodiment of the present application, which enables those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A geopolymer grouting material, characterized in that, The geopolymer grouting material comprises the following raw materials in parts by weight: 20-30 parts red mud, 7-15 parts fly ash and 50-65 parts alkali activator; The alkaline activator is composed of a silica fume-based solution and a modified water glass solution in a weight ratio of (15~19):(7~11); The weight ratio of the red mud to the fly ash is 2.4:1; The preparation of the modified water glass solution includes the following process: water glass solution with a modulus of 2.2-2.5 and polyvinyl alcohol with a degree of polymerization of <2000 are stirred and mixed in a weight ratio of (10~15):(3~7) to obtain the modified water glass solution; The preparation of the silica fume-based solution includes the following process: mixing a potassium hydroxide solution of 40-50% by weight and silica fume in a weight ratio of (3-7):(1-3) to obtain the silica fume-based solution; The preparation method of the geopolymer grouting material includes the following steps: Prepare the alkaline activator; The red mud is first crushed and sieved, and then subjected to oxygen-enriched microwave plasma treatment to obtain modified red mud. The modified red mud, the fly ash, and the alkali activator are stirred and mixed to obtain the geopolymer grouting material; The oxygen-enriched microwave plasma treatment process includes the following steps: The red mud with a particle size of 300-500 mesh after being crushed and sieved was placed in a microwave plasma treatment instrument. A mixed gas consisting of oxygen and argon with a volume ratio of 8:1 was used as the working medium. Under the conditions of microwave power set to 750-850W and gas flow maintained at 100-120 mL / min, glow discharge treatment was performed for 2-5 minutes. Oxygen was then continuously introduced for 10-15 minutes to obtain the modified red mud.

2. The geopolymer grouting material according to claim 1, characterized in that, The geopolymer grouting material comprises the following raw materials in parts by weight: 24 parts red mud, 10 parts fly ash, and 60 parts alkali activator.

3. The geopolymer grouting material according to claim 1, characterized in that, The polyvinyl alcohol includes at least one of polyvinyl alcohol 1799 and polyvinyl alcohol 1788.

4. The geopolymer grouting material according to claim 1, characterized in that, The red mud includes at least one of sintered red mud and Bayer red mud; the fly ash includes secondary fly ash.

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