An environmentally friendly solid binder for refractory materials and its preparation method

Abstract

The present invention relates to the field of refractory additives, specifically an environmentally friendly solid binder for refractory materials and its preparation method. Among them, the environmentally friendly solid binder for refractory materials is composed of the following raw materials in parts by weight: 80-100 parts of geopolymers, 4-12 parts of pseudo-boehmite, 2-7 parts of metakaolin, and 0.5-1.5 parts of water reducer; among them, the geopolymers are composed of the following components in parts by weight: 40-60 parts of coal gangue, 20-35 parts of slag, 10-15 parts of fly ash, 3-8 parts of alkali activator, and 1-4 parts of ZrO2 / carbon fiber nanomaterial. This solid binder is a coal gangue-fly ash-slag geopolymer-based binder, adding ZrO2 / carbon fiber nanomaterial and pseudo-boehmite to enhance the performance, which not only has environmental protection and mechanical properties, but also has high-temperature stability and bonding properties, etc. It is an excellent refractory additive with excellent performance.

Description

Technical Field

[0001] The present invention relates to the field of refractory additives, and specifically to an environment-friendly solid binder for refractory materials and a preparation method thereof. Background Art

[0002] In modern industry, refractory materials are one of the crucial materials, used for heat preservation and heat insulation in high-temperature environments. Refractory materials can be classified into refractory bricks, refractory castables, refractory coatings, refractory fibers, etc. During the preparation process, in addition to the main components such as alumina, magnesia, aluminum silicate, and graphite, a certain proportion of additives are added to improve the performance of refractory materials or add certain specific functions, such as binders, reinforcing agents, anti-cracking agents, antioxidants, corrosion-resistant agents, wear-resistant agents, etc. Among them, the binder is a key component of refractory materials, which can firmly bind refractory materials together, improve mechanical strength and durability. The traditional curing process of refractory materials usually uses liquid binders such as cement, paraffin, and resin. However, these liquid binders have problems such as high emissions of volatile organic compounds (VOCs), complex curing processes, and serious environmental pollution. In order to improve the environmental friendliness of refractory materials, new solid binders are developed for refractory materials to replace traditional liquid binders. Solid binders usually exist in solid or semi-solid forms, but there are also problems to be solved in their research and application, such as the need to improve the bonding strength and high-temperature resistance, complex curing processes, high production costs, etc. Nevertheless, the research and development of environment-friendly solid binders for refractory materials still have important significance, which is conducive to strengthening environmental protection, waste utilization, and enhancing practicality.

[0003] Geopolymer is a high-performance inorganic polymer with good adhesiveness, mainly composed of ionic bonds and covalent bonds, supplemented by van der Waals forces, and also contains a chain structure similar to organic polymers. It has the characteristics of environmental friendliness, good mechanical properties, good interfacial bonding ability, thermal stability, and durability, and can be prepared from solid waste. Therefore, it has practical significance to use geopolymer as a solid binder for refractory materials. Summary of the Invention

[0004] The present invention provides an environment-friendly solid binder for refractory materials and a preparation method thereof, aiming to prepare a new solid binder for refractory materials, avoid environmental pollution caused by high VOC emissions during the use of liquid binders, and also improve the bonding strength and high-temperature stability of the solid binder.

[0005] An environment-friendly solid binder for refractory materials is composed of the following components in parts by weight: 80 - 100 parts of geopolymer, 4 - 12 parts of pseudo-boehmite, 2 - 7 parts of metakaolin, and 0.5 - 1.5 parts of water reducer;

[0006] Among them, the geopolymer is composed of the following components in parts by weight: 40 - 60 parts of coal gangue, 20 - 35 parts of slag, 10 - 15 parts of fly ash, 3 - 8 parts of alkali activator, and 1 - 4 parts of ZrO2 / carbon fiber nanomaterial;

[0007] The alkali activator is composed of the following raw materials in parts by weight: 4 parts of NaOH, 5.6 parts of KOH, 12 - 13.7 parts of silica gel suspension. Both NaOH and KOH are commercially available analytical pure reagents, and the pH of the silica gel suspension is 10;

[0008] The ZrO2 / carbon fiber nanomaterial is prepared from the following raw materials in parts by weight: 4.5 - 5.5 parts of nano - ZrO2 powder, 0.2 - 0.25 parts of carbon fiber. The particle size of the nano - ZrO2 powder is 100nm, the diameter of the carbon fiber is 100 - 200nm, and the length is 2 - 5μm.

[0009] Furthermore, the preparation of the ZrO2 / carbon fiber nanomaterial includes the following steps:

[0010] P1, Take the nano - ZrO2 powder in absolute ethanol, ultrasonically disperse for 20 - 40min, transfer it to a water - bath kettle, add silane coupling agent KH560, heat the water - bath kettle to 50 - 70°C, keep the temperature constant for reaction for 4 - 6h, maintain mechanical stirring during the reaction, with the stirring speed of 400 - 600rpm. After the reaction, centrifuge and wash to remove the excess KH560, and dry in a vacuum drying oven at 70°C for 40 - 90min to obtain modified ZrO2;

[0011] P2, Take the carbon fiber and ultrasonically disperse it in absolute ethanol for 40 - 60min, transfer it to a water - bath kettle, add silane coupling agent KH560, heat the water - bath kettle to 50 - 70°C, keep the temperature constant for reaction for 4 - 6h, maintain mechanical stirring during the reaction, with the stirring speed of 500 - 700rpm to obtain a mixture containing modified carbon fiber;

[0012] P3, Take the modified ZrO2 prepared in step P1 and add it to the mixture containing modified carbon fiber prepared in step P2, react at a constant temperature of 50 - 70°C under mechanical stirring at 300 - 400rpm for 6h to obtain the ZrO2 / carbon fiber nanomaterial.

[0013] Preferably, in step P1, the ratio of the nano - ZrO2 powder to absolute ethanol is 45 - 55g / L, and the ratio of the silane coupling agent KH560 to the nano - ZrO2 powder is 0.15 - 0.18g / mL.

[0014] Preferably, in step P2, the ratio of the carbon fiber to absolute ethanol is 2 - 2.5g / L, and the ratio of the carbon fiber to the silane coupling agent KH560 is 6.7 - 8.3g / L.

[0015] Further, the preparation of the geopolymer comprises the following steps:

[0016] Q1, Take NaOH and KOH and dissolve them in distilled water, stir and mix until dissolved, the stirring speed is 200 rpm, and the stirring time is 10 min to obtain an alkaline aqueous solution;

[0017] Q2, After standing the alkaline aqueous solution prepared in step Q1 for 1 day, slowly add it to the silica gel suspension, and mechanically stir until evenly mixed, the stirring speed is 400 rpm, and the stirring time is 30 - 60 min, seal it with plastic wrap to obtain a transparent solution, which is the alkali activator;

[0018] Q3, Crush the coal gangue with a crusher, grind it in a planetary ball mill for 30 - 60 min, and sieve it through a 120 - mesh sieve to obtain the coal gangue powder for standby. The slag and fly ash are sieved through a 100 - mesh sieve to remove impurities and obtain the sieved slag and sieved fly ash for standby;

[0019] Q4, Take the coal gangue powder, sieved slag and sieved fly ash according to the formula ratio, treat them in an oven at 60 - 70 °C for 60 - 150 min to remove moisture, take them out and mechanically stir and mix, the mechanical stirring speed is 400 - 600 rpm, and the stirring time is 30 - 90 min until evenly mixed to obtain a mixed powder;

[0020] Q5, Slowly add the alkali activator prepared in step Q2 to the mixed powder prepared in step Q4 while mechanically stirring, continue to stir for 20 - 40 min, the stirring speed is 150 rpm, then add the ZrO2 / carbon fiber nanomaterial, and stir at 300 rpm for 30 min to obtain the geopolymer.

[0021] Preferably, the molar ratio of NaOH and KOH in step Q1 is 1:1, and the ratio of NaOH and KOH to distilled water is both 0.5 mol / L.

[0022] Preferably, the mass ratio of NaOH and KOH to the silica gel suspension in step Q2 is 0.7 - 0.8:1.

[0023] Further, the preparation of the solid binder for the environmentally friendly refractory material comprises the following steps:

[0024] S1, Take the geopolymer, pseudoboehmite, metakaolin and water - reducing agent according to the formula ratio, add the pseudoboehmite and metakaolin to the geopolymer, and mix them with a planetary mixer. First, mix at a low speed, stir at 300 - 500 rpm for 1 - 5 min, add the water - reducing agent, and then mix at a high speed, stir at 1000 - 1300 rpm for 5 - 10 min to obtain a mixed slurry;

[0025] S2, transferring the mixed slurry prepared in step S1 to a mold, sealing and curing at 70-100° C. for 20-24 hours to obtain a cured geopolymer, taking it out of the mold and drying it at 80° C. for 10-12 hours, crushing it, and then finely grinding it with a grinder, and passing it through a 120-mesh sieve to obtain an environmentally friendly solid binder for refractory materials.

[0026] Furthermore, the water reducing agent in step S1 is a naphthalene-based water reducing agent.

[0027] The beneficial effects achieved by the present invention are as follows:

[0028] The invention provides an environmentally friendly solid binder for refractory materials and a preparation method thereof. The solid binder is a solid binder composed of coal gangue-slag-fly ash geopolymer as a main component, pseudo-boehmite, metakaolin, ZrO2 / carbon fiber nanomaterial and a water reducer, and is used for the preparation of refractory materials.

[0029] Firstly, coal gangue, slag and fly ash are used as raw materials to prepare geopolymer under the action of alkali activator. The main components of coal gangue are quartz, kaolin and mica. In general, the silicon content is higher than the aluminum content. Adding slag and fly ash is beneficial to balance the raw material composition and improve the activity. In addition, crushing and grinding the coal gangue can produce lattice defects and deformation in the coal gangue while reducing the size of the coal gangue, which is helpful to increase the surface area and activity. The use of alkali activator breaks the Ca-O, Si-O and Al-O bonds in the slag. The alkaline environment provided by the alkali activator and the silicate ions produced by hydrolysis increase the content of active silicon in the mixed slurry, and react with the ions in the system to promote the formation of gel products such as CSH and CASH, forming a dense network structure during the reaction process; secondly, in the preparation of geopolymer, ZrO2 / carbon fiber nanomaterials are added. Carbon fiber has high strength, high modulus and high The characteristics of temperature stability, while ZrO2 has low thermal conductivity and high temperature resistance. ZrO2 / carbon fiber nanomaterials are used in geopolymer-based solid binders. ZrO2 can fill the pores of geopolymers and increase density. When the binder bonds refractory aggregates, ZrO2 / carbon fiber nanomaterials are dispersed in the system with the binder. Under heating or stress conditions, carbon fibers absorb and disperse external stresses through a toughening mechanism to prevent the formation and expansion of cracks, while ZrO2 absorbs energy, prevents crack expansion, and reduces heat conduction, with good heat resistance; finally, pseudo-boehmite is a highly active aluminum oxide substance that can fully react with other materials. Due to its high surface activity, pseudo-boehmite can be used as a good binder, which has a reinforcing effect on the bonding performance of the binder to refractory materials. Pseudo-boehmite can also fill the pores between refractory materials and binders to improve the density and mechanical properties of the materials.

[0030] In summary, the solid binder for refractory materials proposed by the present invention is based on geopolymers with good adhesiveness and plasticity, and is prepared by compounding boehmite, metakaolin, and ZrO2 / carbon fiber nanomaterials. A solid binder for refractory materials with environmental protection, non-toxicity, good fire resistance, and strong bonding performance is obtained, and the reuse of solid wastes such as coal gangue, fly ash, and slag is realized, which has the characteristics of low-carbon environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments or of the present invention, the following will briefly introduce the drawings required for description in the embodiments and comparative examples. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0032] Figure 1 It is a double-line graph of the flexural strength of refractory material specimens prepared by sintering different solid binders at 800 °C and the high-temperature flexural strength of refractory material specimens prepared by sintering at 1050 °C;

[0033] Figure 2 It is a bar graph of the normal-temperature compressive strength of refractory material specimens prepared with different binders at different sintering temperatures. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. The described embodiments are some, but not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0035] Example 1: A solid binder for environmentally friendly refractory materials is composed of the following components in parts by weight: 90 parts of geopolymer, 8 parts of boehmite, 4.5 parts of metakaolin, and 1 part of water reducer;

[0036] Among them, the geopolymer is composed of the following components in parts by weight: 40 parts of coal gangue, 35 parts of slag, 15 parts of fly ash, 3 parts of alkali activator, and 2.5 parts of ZrO2 / carbon fiber nanomaterial;

[0037] The alkali activator is composed of the following raw materials in parts by weight: 4 parts of NaOH, 5.6 parts of KOH, and 12.8 parts of silica gel suspension;

[0038] The ZrO2 / carbon fiber nanomaterial is prepared from the following raw materials by weight: 5 parts of nano-ZrO2 powder, 0.225 parts of carbon fiber. The particle size of the nano-ZrO2 powder is 100 nm, the diameter of the carbon fiber is 150 nm, and the length is 3 μm.

[0039] The preparation of the ZrO2 / carbon fiber nanomaterial includes the following steps:

[0040] P1, Take the nano-ZrO2 powder in anhydrous ethanol, ultrasonically disperse for 20 min, transfer it to a water bath, add the silane coupling agent KH560, heat the water bath to 50 °C, carry out a constant-temperature reaction for 6 h, maintain mechanical stirring during the reaction, the stirring speed is 400 rpm, after the reaction, centrifuge and wash to remove the excess KH560, and dry in a vacuum drying oven at 70 °C for 40 min to obtain modified ZrO2. The ratio of the nano-ZrO2 powder to anhydrous ethanol is 50 g / L, and the ratio of the silane coupling agent KH560 to the nano-ZrO2 powder is 0.167 g / mL;

[0041] P2, Take the carbon fiber and ultrasonically disperse it in anhydrous ethanol, ultrasonically disperse for 40 min, transfer it to a water bath, add the silane coupling agent KH560, heat the water bath to 50 °C, carry out a constant-temperature reaction for 6 h, maintain mechanical stirring during the reaction, the stirring speed is 500 rpm, to obtain a mixture containing modified carbon fiber. The ratio of the carbon fiber to anhydrous ethanol is 2.25 g / L, and the ratio of the carbon fiber to the silane coupling agent KH560 is 7.5 g / L;

[0042] P3, Take the modified ZrO2 prepared in step P1 and add it to the mixture containing modified carbon fiber prepared in step P2, and react for 6 h under a 50 °C constant-temperature water bath and mechanical stirring at 300 rpm to obtain the ZrO2 / carbon fiber nanomaterial.

[0043] The preparation of the geopolymer includes the following steps:

[0044] Q1, Take NaOH and KOH and dissolve them in distilled water, stir and mix until dissolved. The molar ratio of NaOH to KOH is 1:1, and the ratio of both NaOH and KOH to distilled water is 0.5 mol / L. The stirring speed is 200 rpm, and the stirring time is 10 min to obtain an alkaline aqueous solution;

[0045] Q2, After standing the alkaline aqueous solution prepared in step Q1 for 1 day, slowly add it to the silica gel suspension, mechanically stir until evenly mixed, the stirring speed is 400 rpm, the stirring time is 30 min, and seal it with plastic wrap to obtain a transparent solution, which is the alkali activator. The mass ratio of NaOH and KOH to the silica gel suspension is 0.75:1;

[0046] Q3. After crushing the coal gangue with a crusher, grind it in a planetary ball mill for 30 minutes, sieve it through a 120-mesh sieve to obtain the coal gangue powder for standby. Screen the slag and fly ash through a 100-mesh sieve to remove impurities and obtain the sieved slag and sieved fly ash for standby.

[0047] Q4. Take the coal gangue powder, sieved slag and sieved fly ash according to the formula ratio, treat them in an oven at 60 °C for 150 minutes to remove moisture, take them out and mix them by mechanical stirring at a stirring speed of 400 rpm for 90 minutes until evenly mixed to obtain the mixed powder.

[0048] Q5. Slowly add the alkali activator prepared in step Q2 to the mixed powder prepared in step Q4 while mechanically stirring, continue stirring for 20 minutes at a stirring speed of 150 rpm, then add the ZrO2 / carbon fiber nanomaterial and stir at 300 rpm for 30 minutes to obtain the geopolymer.

[0049] The preparation of the solid binder for the environmentally friendly refractory material includes the following steps:

[0050] S1. Take the geopolymer, pseudo-boehmite, metakaolin and water reducer according to the formula ratio. Add the pseudo-boehmite and metakaolin to the geopolymer and mix them with a planetary mixer. First, mix at a low speed, stir at 300 rpm for 5 minutes, add the naphthalene-based water reducer, and then mix at a high speed, stir at 1000 rpm for 10 minutes to obtain the mixed slurry.

[0051] S2. Transfer the mixed slurry prepared in step S1 to a mold, seal it and cure it at 70 °C for 24 hours to obtain the cured geopolymer. After taking it out of the mold, dry it at 80 °C for 10 hours, crush it, and then finely grind it with a grinding machine. After sieving through a 120-mesh sieve, obtain the solid binder for the environmentally friendly refractory material.

[0052] Example 2: A solid binder for an environmentally friendly refractory material is composed of the following components in parts by weight: 90 parts of geopolymer, 8 parts of pseudo-boehmite, 4.5 parts of metakaolin, and 1 part of water reducer;

[0053] Among them, the geopolymer is composed of the following components in parts by weight: 60 parts of coal gangue, 20 parts of slag, 10 parts of fly ash, 8 parts of alkali activator, and 2.5 parts of ZrO2 / carbon fiber nanomaterial;

[0054] The alkali activator is composed of the following raw materials in parts by weight: 4 parts of NaOH, 5.6 parts of KOH, and 12.8 parts of silica gel suspension;

[0055] The ZrO2 / carbon fiber nanomaterial is prepared from the following raw materials in parts by weight: 5 parts of nano-ZrO2 powder, 0.225 parts of carbon fiber. The particle size of the nano-ZrO2 powder is 100 nm, the diameter of the carbon fiber is 150 nm, and the length is 3 μm.

[0056] The preparation of ZrO2 / carbon fiber nanomaterials includes the following steps:

[0057] P1, Take nano-ZrO2 powder in absolute ethanol, ultrasonically disperse for 30 min, transfer to a water bath, add silane coupling agent KH560, heat the water bath to 60 °C, react at a constant temperature for 5 h, maintain mechanical stirring during the reaction, the stirring speed is 500 rpm, after the reaction, centrifuge and wash to remove the excess KH560, dry in a vacuum drying oven at 70 °C for 65 min to obtain modified ZrO2. The ratio of nano-ZrO2 powder to absolute ethanol is 50 g / L, and the ratio of silane coupling agent KH560 to nano-ZrO2 powder is 0.167 g / mL;

[0058] P2, Take carbon fiber and ultrasonically disperse it in absolute ethanol for 50 min, transfer to a water bath, add silane coupling agent KH560, heat the water bath to 60 °C, react at a constant temperature for 5 h, maintain mechanical stirring during the reaction, the stirring speed is 600 rpm to obtain a mixture containing modified carbon fiber. The ratio of carbon fiber to absolute ethanol is 2.25 g / L, and the ratio of carbon fiber to silane coupling agent KH560 is 7.5 g / L;

[0059] P3, Take the modified ZrO2 prepared in step P1 and add it to the mixture containing modified carbon fiber prepared in step P2, react at 60 °C in a constant temperature water bath and under mechanical stirring at 350 rpm for 6 h to obtain ZrO2 / carbon fiber nanomaterials.

[0060] The preparation of geopolymers includes the following steps:

[0061] Q1, Take NaOH and KOH and dissolve them in distilled water, stir and mix until dissolved. The molar ratio of NaOH to KOH is 1:1, and the ratio of both NaOH and KOH to distilled water is 0.5 mol / L. The stirring speed is 200 rpm and the stirring time is 10 min to obtain an alkaline aqueous solution;

[0062] Q2, Let the alkaline aqueous solution prepared in step Q1 stand for 1 day, then slowly add it to the silica gel suspension, stir mechanically until evenly mixed, the stirring speed is 400 rpm, the stirring time is 45 min, and seal it with plastic wrap to obtain a transparent solution, which is the alkali activator. The mass ratio of NaOH and KOH to the silica gel suspension is 0.75:1;

[0063] Q3, After crushing the coal gangue with a crusher, grind it in a planetary ball mill for 45 min, sieve it through a 120-mesh sieve to obtain coal gangue powder for standby. The slag and fly ash are sieved through a 100-mesh sieve to remove impurities and obtain sieved slag and sieved fly ash for standby;

[0064] Q4. Take coal gangue powder, sieved slag, and sieved fly ash according to the formulation ratio, treat them in an oven at 65 °C for 105 min to remove moisture, take them out and mix them by mechanical stirring at a stirring speed of 500 rpm for 60 min until evenly mixed to obtain a mixed powder.

[0065] Q5. Slowly add the alkali activator prepared in step Q2 to the mixed powder prepared in step Q4 while mechanically stirring, continue stirring for 30 min at a stirring speed of 150 rpm, then add ZrO2 / carbon fiber nanomaterial, and stir at 300 rpm for 30 min to obtain geopolymers.

[0066] The preparation of the solid binder for environmentally friendly refractory materials includes the following steps:

[0067] S1. Take geopolymers, pseudo-boehmite, metakaolin, and water reducer according to the formulation ratio, add pseudo-boehmite and metakaolin to the geopolymers, and mix them with a planetary mixer. First, mix at a low speed, stir at 400 rpm for 3 min, add a naphthalene-based water reducer, and then mix at a high speed, stir at 1150 rpm for 7 min to obtain a mixed slurry.

[0068] S2. Transfer the mixed slurry prepared in step S1 to a mold, seal it, cure at 85 °C for 22 h to obtain a cured geopolymer, take it out of the mold and then dry it at 80 °C for 11 h, crush it, and then finely grind it with a pulverizer. After passing through a 120-mesh sieve, obtain the solid binder for environmentally friendly refractory materials.

[0069] Example 3: A solid binder for environmentally friendly refractory materials is composed of the following components in parts by weight: 90 parts of geopolymers, 8 parts of pseudo-boehmite, 4.5 parts of metakaolin, and 1 part of water reducer;

[0070] Among them, the geopolymer is composed of the following components in parts by weight: 50 parts of coal gangue, 27.5 parts of slag, 12.5 parts of fly ash, 5.5 parts of alkali activator, and 1 part of ZrO2 / carbon fiber nanomaterial;

[0071] The alkali activator is composed of the following raw materials in parts by weight: 4 parts of NaOH, 5.6 parts of KOH, and 12.8 parts of silica gel suspension;

[0072] The ZrO2 / carbon fiber nanomaterial is prepared from the following raw materials in parts by weight: 5 parts of nano-ZrO2 powder, 0.225 parts of carbon fiber. The particle size of the nano-ZrO2 powder is 100 nm, the diameter of the carbon fiber is 150 nm, and the length is 3 μm.

[0073] The preparation of the ZrO2 / carbon fiber nanomaterial includes the following steps:

[0074] P1. Take nano-ZrO₂ powder and disperse it in absolute ethanol by ultrasonic for 40 min. Transfer it to a water bath, add silane coupling agent KH560, heat the water bath to 70 °C, and react at a constant temperature for 4 h. During the reaction, keep mechanical stirring at a speed of 600 rpm. After the reaction, centrifuge and wash to remove the excess KH560, and dry it in a vacuum drying oven at 70 °C for 90 min to obtain modified ZrO₂. The ratio of nano-ZrO₂ powder to absolute ethanol is 50 g / L, and the ratio of silane coupling agent KH560 to nano-ZrO₂ powder is 0.167 g / mL.

[0075] P2. Take carbon fiber and disperse it in absolute ethanol by ultrasonic for 60 min. Transfer it to a water bath, add silane coupling agent KH560, heat the water bath to 70 °C, and react at a constant temperature for 4 h. During the reaction, keep mechanical stirring at a speed of 700 rpm to obtain a mixture containing modified carbon fiber. The ratio of carbon fiber to absolute ethanol is 2.25 g / L, and the ratio of carbon fiber to silane coupling agent KH560 is 7.5 g / L.

[0076] P3. Add the modified ZrO₂ prepared in step P1 to the mixture containing modified carbon fiber prepared in step P2, and react at 70 °C in a constant temperature water bath with mechanical stirring at 400 rpm for 6 h to obtain ZrO₂ / carbon fiber nanomaterial.

[0077] The preparation of geopolymers includes the following steps:

[0078] Q1. Take NaOH and KOH and dissolve them in distilled water, stir and mix until dissolved. The molar ratio of NaOH to KOH is 1:1, and the ratio of NaOH and KOH to distilled water is both 0.5 mol / L. Stir at a speed of 200 rpm for 10 min to obtain an alkaline aqueous solution.

[0079] Q2. After standing the alkaline aqueous solution prepared in step Q1 for 1 day, slowly add it to the silica gel suspension, and mechanically stir until evenly mixed at a speed of 400 rpm for 60 min, then seal it with plastic wrap to obtain a transparent solution, which is the alkali activator. The mass ratio of NaOH and KOH to the silica gel suspension is 0.8:1.

[0080] Q3. Crush the coal gangue with a crusher, grind it in a planetary ball mill for 60 min, and sieve it through a 120-mesh sieve to obtain the coal gangue powder for standby. Screen the slag and fly ash through a 100-mesh sieve to remove impurities and obtain the sieved slag and sieved fly ash for standby.

[0081] Q4. Take coal gangue powder, sieved slag and sieved fly ash according to the formula ratio, treat them in an oven at 70 °C for 60 min to remove moisture, take them out and mix them by mechanical stirring at a stirring speed of 600 rpm for 30 min until evenly mixed to obtain a mixed powder.

[0082] Q5. Slowly add the alkali activator prepared in step Q2 to the mixed powder prepared in step Q4 while mechanically stirring, continue to stir for 40 min at a stirring speed of 150 rpm, then add ZrO2 / carbon fiber nanomaterial and stir at 300 rpm for 30 min to obtain geopolymers.

[0083] The preparation of the solid binder for environmentally friendly refractory materials includes the following steps:

[0084] S1. Take geopolymers, pseudoboehmite, metakaolin and water reducer according to the formula ratio, add pseudoboehmite and metakaolin to the geopolymers, and mix them with a planetary mixer. First, mix at a low speed, stir at 500 rpm for 1 min, add naphthalene-based water reducer, and then mix at a high speed, stir at 1300 rpm for 5 min to obtain a mixed slurry.

[0085] S2. Transfer the mixed slurry prepared in step S1 to a mold, seal it and cure it at 100 °C for 20 h to obtain a cured geopolymer. After taking it out of the mold, dry it at 80 °C for 12 h, crush it, and then finely grind it with a grinding machine. After passing through a 120-mesh sieve, the solid binder for environmentally friendly refractory materials is obtained.

[0086] Example 4: A solid binder for environmentally friendly refractory materials consists of the following components in parts by weight: 90 parts of geopolymers, 8 parts of pseudoboehmite, 4.5 parts of metakaolin, and 1 part of water reducer;

[0087] Among them, the geopolymer consists of the following components in parts by weight: 50 parts of coal gangue, 27.5 parts of slag, 12.5 parts of fly ash, 5.5 parts of alkali activator, and 2.5 parts of ZrO2 / carbon fiber nanomaterial;

[0088] The alkali activator consists of the following raw materials in parts by weight: 4 parts of NaOH, 5.6 parts of KOH, and 12.8 parts of silica gel suspension;

[0089] The ZrO2 / carbon fiber nanomaterial is prepared from the following raw materials in parts by weight: 5 parts of nano-ZrO2 powder, 0.225 parts of carbon fiber. The particle size of the nano-ZrO2 powder is 100 nm, the diameter of the carbon fiber is 150 nm, and the length is 3 μm.

[0090] The preparation steps and parameters of the ZrO2 / carbon fiber nanomaterial, the preparation steps and parameters of the geopolymer, and the preparation steps and parameters of the solid binder for environmentally friendly refractory materials are all the same as those in Example 3.

[0091] Example 5: A solid binder for an environmentally friendly refractory material is composed of the following components in parts by weight: 90 parts of geopolymers, 8 parts of pseudo-boehmite, 4.5 parts of metakaolin, and 1 part of water reducing agent;

[0092] Among them, the geopolymers are composed of the following components in parts by weight: 50 parts of coal gangue, 27.5 parts of slag, 12.5 parts of fly ash, 5.5 parts of alkali activator, and 4 parts of ZrO2 / carbon fiber nanomaterial;

[0093] The alkali activator is composed of the following raw materials in parts by weight: 4 parts of NaOH, 5.6 parts of KOH, and 12.8 parts of silica gel suspension;

[0094] The ZrO2 / carbon fiber nanomaterial is prepared from the following raw materials in parts by weight: 5 parts of nano-ZrO2 powder, 0.225 parts of carbon fiber, the particle size of the nano-ZrO2 powder is 100 nm, the diameter of the carbon fiber is 150 nm, and the length is 3 μm.

[0095] The preparation steps and parameters of the ZrO2 / carbon fiber nanomaterial, the preparation steps and parameters of the geopolymers, and the preparation steps and parameters of the solid binder for the environmentally friendly refractory material are all the same as those in Example 3.

[0096] Example 6: A solid binder for an environmentally friendly refractory material is composed of the following components in parts by weight: 80 parts of geopolymers, 12 parts of pseudo-boehmite, 4.5 parts of metakaolin, and 0.5 part of water reducing agent;

[0097] Among them, the geopolymers are composed of the following components in parts by weight: 50 parts of coal gangue, 27.5 parts of slag, 12.5 parts of fly ash, 5.5 parts of alkali activator, and 4 parts of ZrO2 / carbon fiber nanomaterial;

[0098] The alkali activator is composed of the following raw materials in parts by weight: 4 parts of NaOH, 5.6 parts of KOH, and 12.8 parts of silica gel suspension;

[0099] The ZrO2 / carbon fiber nanomaterial is prepared from the following raw materials in parts by weight: 5 parts of nano-ZrO2 powder, 0.225 parts of carbon fiber, the particle size of the nano-ZrO2 powder is 100 nm, the diameter of the carbon fiber is 150 nm, and the length is 3 μm.

[0100] The preparation steps and parameters of the ZrO2 / carbon fiber nanomaterial, the preparation steps and parameters of the geopolymers, and the preparation steps and parameters of the solid binder for the environmentally friendly refractory material are all the same as those in Example 5.

[0101] Example 7: A solid binder for an environmentally friendly refractory material is composed of the following components in parts by weight: 100 parts of geopolymers, 4 parts of pseudo-boehmite, 4.5 parts of metakaolin, and 1.5 parts of water reducing agent;

[0102] Among them, the geopolymer is composed of the following components in parts by weight: 50 parts of coal gangue, 27.5 parts of slag, 12.5 parts of fly ash, 5.5 parts of alkali activator, and 4 parts of ZrO2 / carbon fiber nanomaterial;

[0103] The alkali activator is composed of the following raw materials in parts by weight: 4 parts of NaOH, 5.6 parts of KOH, and 12.8 parts of silica gel suspension;

[0104] The ZrO2 / carbon fiber nanomaterial is prepared from the following raw materials in parts by weight: 5 parts of nano-ZrO2 powder, 0.225 parts of carbon fiber, the particle size of the nano-ZrO2 powder is 100 nm, the diameter of the carbon fiber is 150 nm, and the length is 3 μm.

[0105] The preparation steps and parameters of the ZrO2 / carbon fiber nanomaterial, the preparation steps and parameters of the geopolymer, and the preparation steps and parameters of the solid binder for environmentally friendly refractory materials are all the same as those in Example 5.

[0106] Example 8: A solid binder for environmentally friendly refractory materials is composed of the following components in parts by weight: 90 parts of geopolymer, 8 parts of pseudoboehmite, 4.5 parts of metakaolin, and 1 part of water reducing agent;

[0107] Among them, the geopolymer is composed of the following components in parts by weight: 50 parts of coal gangue, 27.5 parts of slag, 12.5 parts of fly ash, 5.5 parts of alkali activator, and 4 parts of ZrO2 / carbon fiber nanomaterial;

[0108] The alkali activator is composed of the following raw materials in parts by weight: 4 parts of NaOH, 5.6 parts of KOH, and 12.8 parts of silica gel suspension;

[0109] The ZrO2 / carbon fiber nanomaterial is prepared from the following raw materials in parts by weight: 4.5 parts of nano-ZrO2 powder, 0.2 parts of carbon fiber, the particle size of the nano-ZrO2 powder is 100 nm, the diameter of the carbon fiber is 150 nm, and the length is 3 μm.

[0110] The preparation of the ZrO2 / carbon fiber nanomaterial includes the following steps:

[0111] P1, Take the nano-ZrO2 powder in absolute ethanol, ultrasonically disperse for 40 min, transfer it to a water bath, add silane coupling agent KH560, heat the water bath to 70 °C, react at a constant temperature for 4 h, keep mechanical stirring during the reaction, the stirring speed is 600 rpm, after the reaction, centrifuge and wash to remove the excess KH560, and dry in a vacuum drying oven at 70 °C for 90 min to obtain modified ZrO2. The ratio of nano-ZrO2 powder to absolute ethanol is 45 g / L, and the ratio of silane coupling agent KH560 to nano-ZrO2 powder is 0.15 g / mL;

[0112] P2. Take carbon fiber and ultrasonically disperse it in absolute ethanol for 60 min. Transfer it to a water bath, add silane coupling agent KH560, heat the water bath to 70 °C, and carry out a constant-temperature reaction for 4 h. During the reaction process, maintain mechanical stirring at a stirring speed of 700 rpm to obtain a mixture containing modified carbon fiber. The ratio of carbon fiber to absolute ethanol is 2 g / L, and the ratio of carbon fiber to silane coupling agent KH560 is 6.7 g / L;

[0113] P3. Take the modified ZrO2 prepared in step P1 and add it to the mixture containing modified carbon fiber prepared in step P2. React for 6 h under a constant-temperature water bath at 70 °C and mechanical stirring at 400 rpm to obtain ZrO2 / carbon fiber nanomaterial.

[0114] The preparation steps and parameters of geopolymers and the preparation steps and parameters of the solid binder for environmentally friendly refractory materials are the same as those in Example 5.

[0115] Example 9: A solid binder for environmentally friendly refractory materials is composed of the following components in parts by weight: 90 parts of geopolymers, 8 parts of pseudo-boehmite, 4.5 parts of metakaolin, and 1 part of water reducing agent;

[0116] Among them, the geopolymer is composed of the following components in parts by weight: 50 parts of coal gangue, 27.5 parts of slag, 12.5 parts of fly ash, 5.5 parts of alkali activator, and 4 parts of ZrO2 / carbon fiber nanomaterial;

[0117] The alkali activator is composed of the following raw materials in parts by weight: 4 parts of NaOH, 5.6 parts of KOH, and 12.8 parts of silica gel suspension;

[0118] The ZrO2 / carbon fiber nanomaterial is prepared from the following raw materials in parts by weight: 5.5 parts of nano-ZrO2 powder, 0.25 part of carbon fiber. The particle size of the nano-ZrO2 powder is 100 nm, the diameter of the carbon fiber is 150 nm, and the length is 3 μm.

[0119] The preparation of ZrO2 / carbon fiber nanomaterial includes the following steps:

[0120] P1. Take nano-ZrO2 powder in absolute ethanol, ultrasonically disperse it for 40 min, transfer it to a water bath, add silane coupling agent KH560, heat the water bath to 70 °C, and carry out a constant-temperature reaction for 4 h. During the reaction process, maintain mechanical stirring at a stirring speed of 600 rpm. After the reaction, centrifuge and wash to remove the excess KH560, and dry it in a vacuum drying oven at 70 °C for 90 min to obtain modified ZrO2. The ratio of nano-ZrO2 powder to absolute ethanol is 55 g / L, and the ratio of silane coupling agent KH560 to nano-ZrO2 powder is 0.18 g / mL;

[0121] P2. Take carbon fiber and disperse it ultrasonically in absolute ethanol for 60 min. Transfer it to a water bath, add silane coupling agent KH560, heat the water bath to 70 °C, and react at a constant temperature for 4 h. During the reaction, maintain mechanical stirring at a speed of 700 rpm to obtain a mixture containing modified carbon fiber. The ratio of carbon fiber to absolute ethanol is 2.5 g / L, and the ratio of carbon fiber to silane coupling agent KH560 is 8.3 g / L.

[0122] P3. Take the modified ZrO₂ prepared in step P1 and add it to the mixture containing modified carbon fiber prepared in step P2. React under a constant temperature water bath at 70 °C and mechanical stirring at 400 rpm for 6 h to obtain ZrO₂ / carbon fiber nanomaterial.

[0123] The preparation steps and parameters of geopolymers and the preparation steps and parameters of the solid binder for environmentally friendly refractory materials are the same as those in Example 5.

[0124] Comparative Example 1: Based on Example 5, the difference is that ZrO₂ / carbon fiber nanomaterial is not added in the preparation of geopolymers, and the remaining preparation methods and parameters are the same as those in Example 5.

[0125] Comparative Example 2: Based on Example 5, the difference is that slag and fly ash are not added in the preparation of geopolymers, and the remaining preparation methods and parameters are the same as those in Example 5.

[0126] Comparative Example 3: Based on Example 5, the difference is that pseudoboehmite is not added in the preparation of the solid binder for environmentally friendly refractory materials, and the remaining preparation methods and parameters are the same as those in Example 5.

[0127] Experimental Example:

[0128] Weigh according to the weight ratio of refractory aggregate to solid binder of 3:1. First, mix the refractory aggregate in a mixer for 5 min at a mixing speed of 120 rpm, then add the solid binder, water (9.5 wt%), and polyethylene glycol (0.5 wt%) and mix in the mixer. First, mix at a mixing speed of 200 rpm for 3 min, then mix at a mixing speed of 450 rpm for 10 min. Transfer the mixture to a mold, seal and cure at 40 °C for 24 h, dry at 100 °C for 24 h after demolding, and then fire at a sintering temperature of 600 °C to 1200 °C for 2 h. According to the above method, corresponding refractory material test samples are prepared using the solid binders prepared in different examples and comparative examples.

[0129] 1. Bond strength:

[0130] When testing the bonding strength, after transferring the mixture to the mold, the mixture is compacted under a pressure of 20 MPa and then sintered. The sintering temperature of the test specimens of the refractory material is fixed at 800 °C. The determination of the bonding strength is evaluated by testing the flexural strength. The determination of the flexural strength is carried out in accordance with the provisions of GB / T 6569-86. The test uses four-point bending. Five groups of measurements are taken for each specimen and the average value is taken. The calculation formula for determining the flexural strength is as follows:

[0131] σ f = 3Fa / bd 2 ;

[0132] In the formula, σ f —— flexural strength, MPa;

[0133] F —— maximum load, N;

[0134] a —— length of the bending force arm suffered by the specimen, mm;

[0135] b —— width of the specimen, mm;

[0136] d —— height of the specimen parallel to the loading direction, mm.

[0137] The flexural strengths of refractory specimens prepared by sintering with different solid binders at 800 °C are shown in Table 1 and Figure 1 as follows.

[0138] 2. Cold crushing strength:

[0139] The determination of the cold crushing strength is carried out in accordance with the provisions of GB / T 5072-2008. The specimen specification of the refractory material is a cylinder with a diameter and height of 50 mm. Measure two diameters on the two compression surfaces of the specimen that are perpendicular to each other, with an accuracy of 0.1 mm. Calculate the average initial cross-sectional area A0 according to the arithmetic mean of the four diameters. Install the specimen or the adapter with the specimen at the center position of the upper and lower two pressing plates of the testing machine. Do not use any cushioning materials between the specimen and the pressing plates. Select the load range and apply stress continuously and uniformly at a rate of 1 MPa / s until the specimen breaks. Record the maximum load. The cold crushing strength of the specimen is calculated according to the following formula:

[0140] σ = F max / A0;

[0141] In the formula, σ —— cold crushing strength, MPa;

[0142] F max —— recorded maximum load, N;

[0143] A0 —— initial cross-sectional area of the compression surface of the specimen, mm 2 .

[0144] The cold crushing strength of refractory specimens prepared with different binders at different sintering temperatures is shown in Table 2 and Figure 2 as follows.

[0145] 3. Hot modulus of rupture:

[0146] The hot modulus of rupture is measured in accordance with the provisions of GB / T 3002-2017. The specimen size of the refractory is 150 mm × 25 mm × 25 mm. Place the specimen in the experimental furnace. The test temperature is 1050 °C, the heating rate is 5 °C / min, and keep it for 30 min to obtain the refractory specimen. Place the specimen symmetrically under the knife edge, and apply a uniform load (0.15 MPa) vertically in the middle of the pressure surface of the specimen with the upper knife edge until it breaks, and record the maximum load F max at the moment of specimen fracture. Calculate the hot modulus of rupture of the refractory specimen according to the following formula:

[0147] R e = 3 / 2 × F max L s / bh 2 ;

[0148] In the formula, R e —— hot modulus of rupture, MPa;

[0149] F max —— maximum load at the moment of specimen fracture, N;

[0150] L s —— distance between the supporting knife edges, mm;

[0151] b —— width of the specimen, mm;

[0152] h —— height of the specimen, mm.

[0153] The hot modulus of rupture of refractory specimens prepared with different binders sintered at 1050 °C is shown in Table 3 and Figure 1 as follows.

[0154] Table 1 Flexural strength of refractory specimens prepared with different solid binders sintered at 800 °C

[0155]

[0156] Table 2 Cold crushing strength of refractory specimens prepared with different binders at different sintering temperatures

[0157]

[0158] Table 3 Hot modulus of rupture of refractory specimens prepared with different binders sintered at 1050 °C

[0159]

[0160] In the experimental examples, refractory material specimens were prepared by combining different solid binders prepared in each example with refractory aggregates, and their performance was tested. The test results are shown in Tables 1 to 3 and Figures 1 - 2 as shown.

[0161] Examples 1, 4, and 2 were compared and studied to investigate the effect of increasing the addition amount of coal gangue and decreasing the addition amounts of slag and fly ash on the performance of the specimens. Since slag and fly ash help balance the raw material composition in the system and improve the activity, geopolymers can generate gel materials with a dense network structure under the action of an alkali activator. The refractory material prepared with this as the binder has an increased flexural strength, indicating that the material is dense, uniform, has high overall strength, and has a large bonding strength between the binder and the refractory aggregates. When the weight ratio of coal gangue to slag and fly ash is 50:27.5:12.5, the prepared solid binder for refractory materials can achieve a high recycling rate of coal gangue while maintaining a high bonding strength. Therefore, this ratio was selected for subsequent examples; its cold crushing strength first increases and then decreases with the sintering temperature, which also results from the change in the reaction activity and structural compactness of geopolymers. Excessive sintering temperature will cause changes in the geopolymer structure and affect the synergistic effect between components, resulting in a decrease in the cold crushing strength; at a fixed sintering temperature, its high-temperature flexural strength also increases with the increase in fly ash and slag.

[0162] From the comparison of Examples 3, 4, and 5, it can be seen that as the dosage of ZrO2 / carbon fiber nanomaterials increases, the flexural strength and bond strength of the prepared refractory materials increase. This is because of the high modulus and high strength of carbon fibers and the good toughening effect of ZrO2. Dispersing ZrO2 / carbon fiber nanomaterials in geopolymers as refractory binders can transfer and disperse stress, prevent crack propagation, and improve interfacial bonding. As the sintering temperature increases, the cold compressive strength first increases and then decreases. This is because at lower sintering temperatures, ZrO2 / carbon fiber nanomaterials can effectively fill the voids in the geopolymer matrix, enhance the densification of the matrix and the overall structural strength. When the sintering temperature rises, the structure of the geopolymer becomes more compact, which is beneficial to the bonding with refractory aggregates. However, when the temperature is too high, the geopolymer undergoes a phase change, and the dispersion of ZrO2 / carbon fiber nanomaterials is affected, resulting in a decrease in cold compressive strength. At this time, the dosages of geopolymer and ZrO2 / carbon fiber nanomaterials in the solid binder need to be adjusted. ZrO2 / carbon fiber nanomaterials are beneficial to improving the high-temperature stability of the prepared solid binder. Therefore, when the solid binder is combined with refractory aggregates to prepare refractory materials, its high-temperature flexural strength will increase significantly. This is because ZrO2 / carbon fiber nanomaterials can maintain the structural integrity and strength of geopolymers under high-temperature conditions, making the bonding between the solid binder and refractory aggregates tighter and more stable.

[0163] Examples 6, 5, and 7 mainly reflect the influence of the raw material composition of the solid binder on the properties of the specimens. Geopolymers themselves have good bonding properties. When the dosage of geopolymers increases, the bonding properties of the solid binder increase, and its flexural strength also increases. The increase in pseudoboehmite can improve the reaction activity between the components of the solid binder, fill voids, and improve the densification and mechanical properties of the material. Therefore, there is a synergistic effect between geopolymers and pseudoboehmite. The addition of pseudoboehmite increases the cold compressive strength, but when added in excess, it will decrease due to the agglomeration of nanoparticles and other reasons. The influence of different sintering temperatures on the cold compressive strength also first increases and then decreases. Pseudoboehmite has good thermal stability and can maintain the structural integrity at high temperatures. It can act as a reinforcing phase at high temperatures to provide support and strengthening effects, and improve the high-temperature flexural strength.

[0164] Examples 8, 5, and 9 mainly reflect the influence of ZrO2 / carbon fiber nanomaterials prepared with different raw material ratios on the properties. When the dosages of ZrO2 and carbon fibers increase, the ZrO2 / carbon fiber nanomaterials contain more ZrO2 and carbon fibers, which is beneficial to performance improvement. However, even if the dispersion is improved through modification to better avoid agglomeration, if the addition amount is too large, it will cause partial agglomeration or uneven distribution, resulting in a decrease in performance.

[0165] Comparative Examples 1, 2, and 3 respectively reflect the influence of ZrO2 / carbon fiber nanomaterials in geopolymers, fly ash and slag in geopolymers on the performance of the prepared solid binder, and the strengthening effect of pseudoboehmite on the performance. Combining with each example, it can be seen that the influence of these factors on various performances is significant, indicating their important role in this solid binder system and having good bonding strength, mechanical properties and high temperature resistance when preparing refractory materials.

[0166] The above describes the present invention and its embodiments, such description is not restrictive, and what is shown in the drawings is only one of the embodiments of the present invention, and the actual application is not limited thereto. Generally speaking, if those of ordinary skill in the art are inspired by it and without departing from the purpose of the present invention, and design similar ways and embodiments to this technical solution without creative efforts, they should all fall within the protection scope of the present invention.

Claims

1. An environmentally friendly solid binder for refractory materials, characterized in that, It consists of the following components in parts by weight: 80 - 100 parts of geopolymers, 4 - 12 parts of pseudo - boehmite, 2 - 7 parts of metakaolin, 0.5 - 1.5 parts of water - reducing agent; The said geopolymers consist of the following components in parts by weight: 40 - 60 parts of coal gangue, 20 - 35 parts of slag, 10 - 15 parts of fly ash, 3 - 8 parts of alkali activator, 1 - 4 parts of ZrO₂ / carbon fiber nanomaterial; The said alkali activator consists of the following raw materials in parts by weight: 4 parts of NaOH, 5.6 parts of KOH, 12 - 13.7 parts of silica gel suspension; The said ZrO₂ / carbon fiber nanomaterial is prepared from the following raw materials in parts by weight: 4.5 - 5.5 parts of nano - ZrO₂ powder, 0.2 - 0.25 parts of carbon fiber; The preparation of the said ZrO₂ / carbon fiber nanomaterial includes the following steps: P1, Take nano - ZrO₂ powder in absolute ethanol, keep it in a constant - temperature water bath, add silane coupling agent KH560, maintain mechanical stirring during the reaction, after the reaction, centrifuge, wash and dry to obtain modified ZrO₂; P2, Take carbon fiber, ultrasonically disperse it in absolute ethanol, transfer it to a constant - temperature water bath, add silane coupling agent KH560, and maintain mechanical stirring during the reaction to obtain a mixture containing modified carbon fiber; P3, Take the modified ZrO₂ prepared in step P1 and add it to the mixture containing modified carbon fiber prepared in step P2, keep it in a constant - temperature water bath and carry out mechanical stirring reaction to obtain ZrO₂ / carbon fiber nanomaterial; The preparation of the said geopolymers includes the following steps: Q1, Take NaOH and KOH and dissolve them in distilled water, stir and mix until dissolved to obtain an alkaline aqueous solution; Q2, Let the alkaline aqueous solution prepared in step Q1 stand still, slowly add it to the silica gel suspension, mechanically stir until evenly mixed, and seal it with plastic wrap to obtain a transparent solution, which is the alkali activator; Q3, Crush and grind the coal gangue, sieve it through a 120 - mesh sieve to obtain coal gangue powder for standby, sieve the slag and fly ash through a 100 - mesh sieve to remove impurities to obtain sieved slag and sieved fly ash; Q4, Take the coal gangue powder, sieved slag and sieved fly ash according to the formula ratio, treat them in an oven to remove moisture, take them out and mechanically stir and mix until evenly mixed to obtain a mixed powder; Q5, Slowly add the alkali activator prepared in step Q2 to the mixed powder prepared in step Q4 while mechanically stirring, continue to stir after the addition of the alkali activator, then add the nanomaterial, stir and mix until homogeneous to obtain geopolymers; The preparation method of the said solid binder for environmentally friendly refractory materials includes the following steps: S1, Take geopolymers, pseudo - boehmite, metakaolin and water - reducing agent according to the formula ratio, add pseudo - boehmite and metakaolin to the geopolymers, mechanically mix, first mix at low speed, add the water - reducing agent, and then mix at high speed to obtain a mixed slurry; S2, Transfer the mixed slurry prepared in step S1 to a mold, seal it and cure to obtain a cured geopolymer, take it out of the mold, then dry, crush and finely grind it, and sieve it through a 120 - mesh sieve to obtain the solid binder for environmentally friendly refractory materials.

2. The solid binder for an environmentally friendly refractory material according to claim 1, characterized in that, The ratio of the nano-ZrO₂ powder to absolute ethanol described in step P1 is 45 - 55 g / L, and the ratio of the silane coupling agent KH560 to the nano-ZrO₂ powder is 0.15 - 0.18 g / mL.

3. The solid binder for an environment-friendly refractory material according to claim 2, characterized in that, The ratio of the carbon fiber to absolute ethanol described in step P2 is 2 - 2.5 g / L, and the ratio of the carbon fiber to the silane coupling agent KH560 is 6.7 - 8.3 g / L.

4. An environmentally friendly solid binder for refractory materials according to claim 3, characterized in that The molar ratio of NaOH to KOH described in step Q1 is 1:1, and the ratio of both NaOH and KOH to distilled water is 0.5 mol / L.

5. An environmentally friendly solid binder for refractory materials according to claim 4, characterized in that, The mass ratio of NaOH and KOH to the silica gel suspension described in step Q2 is 0.7 - 0.8:

1.

6. The solid binder for an environment-friendly refractory material according to claim 5, characterized in that, The water reducing agent described in step S1 is a naphthalene-based water reducing agent.

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