A polymeric hybrid geopolymer composite anchoring material and a method of making the same

Abstract

The application discloses a kind of high polymer hybrid geopolymer composite anchoring materials and preparation method thereof, the anchoring material includes metakaolin, superfine blast furnace slag, red mud, silicon carbide fiber, silica fume, alunite, cellulose nanocrystal, nano-silica sol, silane coupling agent, isocyanate, polyether polyol.Preparation method is to carry out composite with the geopolymer system of metakaolin, superfine blast furnace slag, red mud and water glass composition with polyurethane nanometer material hybrid body, and add silica fume, silicon carbide fiber and a small amount of alunite, finally form a kind of high polymer hybrid geopolymer composite anchoring material with close and firm three-dimensional interpenetrating network structure system.The composite anchoring material;The addition of silicon carbide fiber and alunite effectively solves the bending resistance of geopolymer and shrinkage problem, so that the performance of composite material tends to be perfect.

Description

Technical Field

[0001] This invention relates to the field of composite anchoring materials for coal mine roadway reinforcement, and particularly to a polymer hybrid geopolymer composite anchoring material and its preparation method. Background Technology

[0002] Excavation of coal mine roadways increases disturbance to the surrounding rock, leading to the development and penetration of rock fissures, which alters the stress distribution in the rock mass. This weakens the stability of the excavation face and makes it prone to disasters such as fracturing and collapse, affecting construction progress and potentially endangering life and property. Therefore, reinforcing coal mine roadways is a necessary engineering construction principle.

[0003] Anchor bolt (cable) support is a commonly used support method in coal mines, generally used alternately with tunneling during roadway excavation to ensure the stability of the surrounding rock. Due to the complex geological environment underground and the numerous unstable factors (such as acid and alkali corrosion, water inrush, high ground temperature, and gas), the requirements for anchoring agents are high. High-performance anchoring materials are beneficial to improving the anchoring effect and the durability and stability of the support structure.

[0004] Currently, commonly used anchoring materials are cement-based anchoring materials and resin anchoring materials. However, cement-based anchoring materials have engineering problems such as poor corrosion resistance, large shrinkage and creep, and susceptibility to blistering and cracking. Although they can be used for temporary support, they are difficult to protect the anchor rod from corrosion and are not suitable for long-term support stability in roadways. In addition, resin anchoring agents are prone to problems such as poor storage stability, mortar delamination, and low strength, which limits their applicability. Summary of the Invention

[0005] In view of the defects or deficiencies of the prior art, the present invention provides a polymer hybrid geopolymer composite anchoring material.

[0006] Therefore, the anchoring material provided by the present invention comprises 500-600 parts by weight of metakaolin, 150-250 parts by weight of ultrafine blast furnace slag, 150-200 parts by weight of red mud, 20-40 parts by weight of silicon carbide fiber, 40-60 parts by weight of silica fume, 3-5 parts by weight of alunite, 10-20 parts by weight of cellulose nanocrystals, 40-60 parts by weight of nano silica sol, 0.5 parts by weight of silane coupling agent, 10-15 parts by weight of isocyanate, and 10-15 parts by weight of polyether polyol; and the isocyanate and polyether polyol have the same number of parts by weight.

[0007] Furthermore, it also includes 200-300 parts by weight of water glass and 1000-1500 parts by weight of water.

[0008] Optionally, the modulus of the water glass is 1.2-1.8.

[0009] Optionally, the pH of the nano-silica sol is 6.5-7.5.

[0010] Optionally, the silane coupling agent is γ-aminopropyltriethoxysilane.

[0011] The present invention also provides a method for preparing the above-mentioned anchoring material. The preparation method includes the following steps:

[0012] S1, mix the formula proportions of kaolin, ultrafine blast furnace slag, red mud, silicon carbide fiber, silica fume and alunite to obtain component A;

[0013] S2, at 60-80℃, a formula amount of silane coupling agent is added dropwise to a mixed solution containing a formula amount of cellulose nanocrystals and nano silica sol. After the reaction is completed, the temperature is lowered to room temperature to obtain silane-coupled nanomaterials.

[0014] S3, the prescribed amounts of isocyanate, polyether polyol, reaction solvent, and solution containing the nanomaterials obtained in S2 are each added to the reactor by atomization to carry out the reaction. The temperature inside the reactor is 100-120℃. After the reaction is completed, the solid product is collected to obtain component B.

[0015] The method further includes the following step: S4, mixing component A, component B, and the prescribed amounts of water and water glass to obtain the anchoring material.

[0016] Optionally, the atomization is generated by an inert gas flow, and the pressure of the inert gas flow is 8 to 12 MPa.

[0017] The anchoring material of this invention exhibits high consolidation strength, good stability, excellent resistance to ion corrosion, and good thermal stability and durability, significantly improving the anchoring effect and mitigating the risk of anchor body instability under long-term adverse geological conditions. Furthermore, the material's extremely high mechanical properties provide strong support for the anchoring structure's support capacity. Detailed Implementation

[0018] Unless otherwise specified, the scientific and technical terms used in this article are intended for understanding by those skilled in the art.

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] This invention hybridizes polyurethane (obtained by reacting isocyanate and polyether polyol), nano-silica sol, and cellulose nanocrystals to obtain a hybrid. This hybrid is then combined with a geopolymer system composed of metakaolin, ultrafine blast furnace slag, and red mud, with the addition of silica fume, silicon carbide fibers, and a small amount of alunite, ultimately forming a polymeric hybrid geopolymer composite anchoring material. Furthermore, under the stimulation of water glass, metakaolin, ultrafine blast furnace slag, and red mud undergo depolymerization and condensation reactions. During this process, the shared oxygen atoms of the polymeric hybrid and the geopolymer alternately bond [SiO4]. 4- and [AlO4] 5- The tetrahedral network structure forms a tight and robust three-dimensional interpenetrating network structure system of geopolymer oxides. Furthermore, the addition of silicon carbide fibers and alunite effectively solves the problems of poor flexural strength and shrinkage of the geopolymer, thus improving the performance of the composite material.

[0021] The reaction solvent used in step S3 of this invention can uniformly disperse the components, allowing the polyurethane and nanomaterials to react more fully and obtain a polymer hybrid with better performance. The reaction solvent does not participate in the reaction and is removed during the recovery of the solid product.

[0022] The particle size range of the ultrafine blast furnace slag of this invention is approximately 30–60 μm or 300–500 mesh.

[0023] It should be noted that the composite anchoring material obtained after step S4 should be used in a timely manner to prevent it from solidifying and losing its fluidity. If the anchoring material is not needed for the time being, only steps S1-S3 to prepare the raw materials are required, and step S4 is carried out on the construction site.

[0024] It should be noted that, unless otherwise specified, the test methods described in the following implementation schemes are conventional methods, and the reagents and materials mentioned are commercially available. The modulus of the water glass used is 1.2-1.8; the nano-silica sol is a neutral sol with a pH of approximately 6.5-7.5, commercially available; the silane coupling agent is γ-aminopropyltriethoxysilane, model KH550; the isocyanate is PM-200, commercially available; the polyether polyol is... 589M, commercially available; the ultrafine blast furnace slag used is 30-60μm.

[0025] Example 1:

[0026] The raw materials for preparing the anchoring material in this embodiment, by weight, include 600 parts metakaolin, 240 parts ultrafine blast furnace slag, 160 parts red mud, 30 parts silicon carbide fiber, 40 parts silica fume, 3 parts alunite, 15 parts cellulose nanocrystals, 60 parts nano silica sol, 0.5 parts silane coupling agent, 10 parts isocyanate, 10 parts polyether polyol, 240 parts water glass, and 1200 parts water; the preparation process also uses 30 parts toluene and 50 parts anhydrous ethanol.

[0027] The specific preparation method is as follows:

[0028] S1. Take metakaolin, ultrafine blast furnace slag, red mud, silicon carbide fiber, silica fume and alum stone, put them into a closed mixing tank, stir slowly for 10-15 minutes, then stir rapidly for 20-30 minutes to fully mix the components and obtain a uniformly dispersed powder, i.e. component A.

[0029] S2, cellulose nanocrystals are dissolved in anhydrous ethanol and nano-silica sol is added. The mixture is then ultrasonically treated at room temperature for 30 minutes. The mixture is then transferred to a stirred tank with a heating function, and a silane coupling agent is slowly added dropwise at 70°C. The mixture is then stirred at 1800 r / min for 5-10 minutes. After cooling, the silane-coupled nanomaterials are obtained.

[0030] S3, isocyanate, polyether polyol, toluene (reaction solvent) and anhydrous ethanol solution of nanomaterials obtained in S2 are respectively atomized into tiny droplets with high specific surface area under a nitrogen atmosphere and a pressure of about 10 MPa through a slurry delivery pipe. Hybridization is carried out in the reaction vessel, and the temperature in the reaction vessel is maintained at about 110°C. After one hour of reaction, the reaction mixture is centrifuged and dried to obtain a polymer hybrid, i.e. component B.

[0031] S4. Add water and water glass to the mixing tank in sequence and stir slowly until homogeneous. Then add component A and component B to the mixing tank and stir slowly for 5 minutes, then stir quickly for 5-10 minutes to obtain the polymer hybrid geopolymer composite anchoring material.

[0032] Example 2:

[0033] The raw materials for preparing the anchoring material in this embodiment are: 500 parts metakaolin, 150 parts ultrafine blast furnace slag, 200 parts red mud, 20 parts silicon carbide fiber, 60 parts silica fume, 3 parts alunite, 20 parts cellulose nanocrystals, 40 parts nano silica sol, 15 parts isocyanate, 15 parts polyether polyol, 0.5 parts silane coupling agent, 1500 parts water, and 200 parts water glass; 50 parts toluene and 60 parts anhydrous ethanol were also used; and the material was prepared using the method described in Example 1.

[0034] Comparative Example 1:

[0035] The difference between this comparative example and Example 1 is that silicon carbide fibers are not added.

[0036] Comparative Example 2:

[0037] The difference between this comparative example and Example 1 is that alum stone was not added.

[0038] Comparative Example 3:

[0039] The difference between this comparative example and Example 1 is that silicon carbide fibers and alum are not added.

[0040] Comparative Example 4:

[0041] The difference between this comparative example and Comparative Document 1 is that, in step S3, the high-pressure gas flow atomization method is not used to process the raw materials of component B. Instead, the anhydrous ethanol dispersion of nanomaterials after coupling treatment of isocyanate, polyether polyol, toluene and silane is directly added to a 110°C reactor and stirred for one hour. After stirring, the reaction mixture is centrifuged and dried to obtain component B. The remaining steps are the same.

[0042] The properties of the materials obtained in Examples 1-2 and Comparative Examples 1-4 were tested. Compressive strength was obtained through a uniaxial compressive strength test; flexural strength was obtained through a three-point flexural test; and bond strength was obtained through a pull-out test. The retention rates of compressive and flexural strengths were conducted according to GB / T50107-2010. Durability was tested using the electric flux method in GB / T 50082-2009 (a higher electric flux indicates lower chloride ion resistance, correspondingly worse durability). The results are shown in Table 1.

[0043] Table 1

[0044]

[0045]

[0046] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A polymer hybrid geopolymer composite anchoring material, characterized in that, The anchoring material comprises 500-600 parts by weight of metakaolin, 150-250 parts by weight of ultrafine blast furnace slag, 150-200 parts by weight of red mud, 20-40 parts by weight of silicon carbide fiber, 40-60 parts by weight of silica fume, 3-5 parts by weight of alunite, 10-20 parts by weight of cellulose nanocrystals, 40-60 parts by weight of nano-silica sol, 0.5 parts by weight of silane coupling agent, 10-15 parts by weight of isocyanate, 10-15 parts by weight of polyether polyol, 200-300 parts by weight of water glass, and 1000-1500 parts by weight of water; and the isocyanate and polyether polyol are in the same weight percentage. The method for preparing the anchoring material includes the following steps: S1, mix the formula proportions of kaolin, ultrafine blast furnace slag, red mud, silicon carbide fiber, silica fume and alunite to obtain component A; S2, at 60-80℃, a formula amount of silane coupling agent is added dropwise to a mixed solution containing a formula amount of cellulose nanocrystals and nano silica sol. After the reaction is completed, the temperature is lowered to room temperature to obtain silane-coupled nanomaterials. S3, the formula amount of isocyanate, the formula amount of polyether polyol, the reaction solvent and the solution containing the nanomaterial obtained in S2 are added to the reactor by atomization to carry out the reaction. The temperature inside the reactor is 100-120℃. After the reaction is completed, the solid product is collected to obtain component B. S4, mix component A, component B, and the prescribed amounts of water and water glass to obtain the anchoring material.

2. The polymer hybrid geopolymer composite anchoring material according to claim 1, characterized in that, The modulus of the water glass is 1.2-1.

8.

3. The polymer hybrid geopolymer composite anchoring material according to claim 1, characterized in that, The pH of the nano-silica sol is 6.5-7.

5.

4. The polymer hybrid geopolymer composite anchoring material according to claim 1, characterized in that, The silane coupling agent is γ-aminopropyltriethoxysilane.

5. The polymer hybrid geopolymer composite anchoring material according to claim 1, characterized in that, The atomization is achieved by an inert gas flow, and the pressure of the inert gas flow is 8-12 MPa.

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