A preparation process for a solid waste-based high-strength foamed ceramic building material

Abstract

This invention relates to the field of ceramic building materials, specifically disclosing a preparation process for a solid waste-based high-strength foamed ceramic building material, comprising the following steps: (1) treating short-cut rock wool fibers with an alkaline solution and then reacting them with a solution containing Ca. 2+ Source, Mg 2+ Source, Al 3+ The source solution is mixed, and then a composite alkaline solution formed by carbonate and alkali solution is added dropwise under stirring until precipitation is complete to obtain a mixed reaction system. (2) After the mixed reaction system is subjected to hydrothermal reaction, the fiber is separated and dried to obtain the strength enhancer. (3) Granite sawdust, graphite tailings powder, red mud powder, magnesium carbonate powder and the strength enhancer are used as raw materials, mixed and sintered, and then cooled to room temperature to obtain foamed ceramic; then the foamed ceramic is placed in potassium dihydrogen phosphate solution and left to stand, and the foamed ceramic building material is obtained. This invention effectively improves the mechanical strength and toughness of foamed ceramic by using modified rock wool fiber and post-treatment process.

Description

Technical Field

[0001] This invention relates to the field of ceramic building materials, specifically to a preparation process for a solid waste-based high-strength foamed ceramic building material. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Compared to organic insulation materials, inorganic insulation materials offer advantages such as aging resistance, low deformation coefficient, and high bonding strength with surface materials, as well as excellent fire resistance. Therefore, inorganic insulation materials have broad application prospects. Foamed ceramics, as a high-temperature calcined inorganic material, possess advantages such as high porosity, low thermal conductivity, high temperature resistance, corrosion resistance, weather resistance, aging resistance, and sound absorption and noise reduction. More importantly, it overcomes the disadvantages of organic insulation materials, such as flammability, short lifespan, and rapid degradation of insulation performance, while also overcoming the safety hazards caused by the thickening of ordinary inorganic insulation materials. It is a comprehensive insulation material with superior performance. Furthermore, the raw materials for foamed ceramics can utilize industrial solid waste, mining solid waste, and construction waste. Therefore, foamed ceramic materials can utilize large amounts of solid waste while achieving excellent thermal insulation performance, possessing broad application prospects and profound development potential. However, due to the large number of pores in foamed ceramics, their strength and toughness are insufficient, making it difficult to meet the needs of some applications requiring high strength, thus limiting the application of foamed ceramics. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a preparation process for high-strength foamed ceramic building materials based on solid waste. This process effectively improves the mechanical strength and toughness of the foamed ceramics by employing modified rock wool fibers and post-processing techniques, overcoming the shortcomings of traditional foamed ceramics in terms of mechanical properties. Specifically, the technical solution of this invention is as follows.

[0005] A preparation process for a solid waste-based high-strength foamed ceramic building material includes the following steps: (1) The chopped rock wool fibers were placed in an alkaline solution and stirred. After the reaction was completed, the pretreated fibers were mixed with Ca... 2+ Source, Mg 2+ Source, Al 3+ The source solution is mixed, and then a composite alkaline solution formed by carbonate and alkali solution is added dropwise under stirring until precipitation is complete, resulting in a mixed reaction system for later use.

[0006] (2) The mixed reaction system is subjected to hydrothermal reaction. After completion, the fiber is separated and dried to obtain the strength enhancer for later use.

[0007] (3) Using granite sawdust, graphite tailings powder, red mud powder, magnesium carbonate powder, and the strength enhancer as raw materials, they are mixed and sintered. After completion, the mixture is cooled to room temperature to obtain foamed ceramic. Then, the foamed ceramic is placed in a potassium dihydrogen phosphate solution and allowed to stand. After completion, the foamed ceramic building material is obtained.

[0008] Further, in step (1), the ratio of the chopped rock wool fiber to the alkaline solution is 1g:10~20mL. Optionally, the length of the chopped rock wool fiber is 3~8mm.

[0009] Further, in step (1), the concentration of the alkaline solution is 1.5~3 mol / L. Optionally, the alkaline solution includes at least one of sodium hydroxide, potassium hydroxide solution, etc.

[0010] Furthermore, in step (1), the stirring process takes 6 to 8 hours.

[0011] Further, in step (1), the pretreated fiber contains Ca 2+ Source, Mg 2+ Source, Al 3+ The solution ratio of the source is 1g: 30~50mL.

[0012] Further, in step (1), the Ca 2+ Source, Mg 2+ Source, Al 3+ The Ca provided by the source 2+ Mg 2+ Al 3+ The molar ratio is 1:2:0.75~1.5.

[0013] Further, in step (1), the Ca 2+ The source includes at least one of calcium chloride, calcium nitrate, etc. The Mg... 2+ The source includes at least one of magnesium chloride, magnesium nitrate, etc. The Al 3+ The source includes at least one of aluminum chloride, aluminum nitrate, etc.

[0014] Further, in step (1), the pH of the system is controlled between 9.5 and 11 by adding the composite alkaline solution. Optionally, the molar ratio of carbonate to alkali in the composite alkaline solution is 2 to 3:1.

[0015] Further, in step (1), the carbonate includes at least one of sodium carbonate, potassium carbonate, ammonium carbonate, etc.

[0016] Further, in step (1), the alkaline solution includes at least one of sodium hydroxide, potassium hydroxide solution, etc.

[0017] Furthermore, in step (2), the temperature of the hydrothermal reaction is 120~160℃ and the time is 8~10 hours.

[0018] Further, in step (3), the proportions of each component in the raw material are as follows: 55-68 parts by weight of granite sawdust, 10-20 parts by weight of graphite tailings powder, 3-4 parts by weight of red mud powder, 0.8-1.5 parts by weight of magnesium carbonate powder, and 2-3.5 parts by weight of strength enhancer.

[0019] Furthermore, in step (3), the sintering temperature is 1080~1150℃ and the time is 20~40min.

[0020] Further, in step (3), the mass fraction of the potassium dihydrogen phosphate solution is 20-30%. Optionally, the standing time is 12-18 hours.

[0021] Compared with the prior art, the technical solution of the present invention has at least the following beneficial effects: To address the common problem of insufficient strength in traditional foamed ceramic materials, this invention employs two methods. First, it uses rock wool fiber as a carrier and modifies it to form a strength-enhancing agent with better adhesion to the foamed ceramic matrix, effectively improving the mechanical strength of the foamed ceramic. Second, it further enhances the strength of the foamed ceramic by immersing it in a potassium dihydrogen phosphate solution for post-treatment. To this end, the rock wool fiber is first treated with an alkaline solution to depolymerize its inert silica and alumina tetrahedral structures, forming an active surface. Then, the fiber undergoes a hydrothermal reaction to form calcium magnesium aluminum hydrotalcite on the active surface, simultaneously roughening the fiber surface. When the strength-enhancing agent obtained through the above treatment is added to the raw materials and the foamed ceramic is fired, the calcium oxide and alumina formed by the decomposition of the calcium magnesium aluminum hydrotalcite react with the silica in the raw materials and the silica on the fiber surface to form a low-melting-point eutectic. After cooling and solidification, this eutectic allows for a more robust bond between the fiber and the foamed ceramic matrix. Furthermore, the roughened fiber surface enhances the mechanical interlocking with the matrix, effectively improving the fiber's contribution to the strength and toughness of the foamed ceramic material. Furthermore, the magnesium oxide formed by the decomposition of calcium magnesium aluminum hydrotalcite on the fiber surface, and the magnesium olivine crystals formed by the reaction of silica in the raw materials and silica on the fiber surface are interwoven and distributed in the pore walls of the foamed ceramic material, which can significantly improve the pore wall strength. Further, this invention involves immersing the foamed ceramic in a potassium dihydrogen phosphate solution for post-treatment, allowing the unreacted byproduct magnesium oxide formed during the foaming process of magnesium carbonate to combine with the potassium dihydrogen phosphate to form struvite, a high-strength, high-adhesion hydrated product. This struvite can repair and strengthen the pore walls, defects, and weak points of the foamed ceramic material, thereby further improving the strength of the foamed ceramic material of this invention. Attached Figure Description

[0022] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention and do not constitute an undue limitation of the invention.

[0023] Figure 1 The image shows a sample of the strength enhancer prepared in Example 1 below.

[0024] Figure 2 The image shows a sample of the foamed ceramic building material prepared in Example 1 below.

[0025] Figure 3 The image shows a sample of the strength enhancer prepared in Example 2 below.

[0026] Figure 4 The image shows a sample of the foamed ceramic building material prepared in Example 2 below.

[0027] Figure 5 The image shows a sample of the strength enhancer prepared in Example 3 below.

[0028] Figure 6 The image shows a sample of the foamed ceramic building material prepared in Example 3 below.

[0029] Figure 7 The image shows a sample of the foamed ceramic building material prepared in Example 4 below.

[0030] Figure 8 The image shows a sample of the foamed ceramic building material prepared in Example 5 below.

[0031] Figure 9 The image shows a sample of the strength enhancer prepared in Example 6 below.

[0032] Figure 10 The image shows a sample of the foamed ceramic building material prepared in Example 6 below.

[0033] Figure 11 The image shows a sample of the strength enhancer prepared in Example 7 below.

[0034] Figure 12 The image shows a sample of the foamed ceramic building material prepared in Example 7 below.

[0035] Figure 13 The image shows a sample of the foamed ceramic building material prepared in Example 8 below. Detailed Implementation

[0036] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the invention. Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as those skilled in the art. The preferred embodiments and materials described in this invention are for illustrative purposes only. The technical solutions of the present invention will now be further described with reference to specific embodiments.

[0037] In the following examples, the composition of the granite sawdust is as follows: SiO2 67.89 wt.%, Al2O3 14.57 wt.%, Na2O 4.72 wt.%, K2O 4.40 wt.%, Fe2O3 3.23 wt.%, CaO 2.78 wt.%, MgO 1.26 wt.%, TiO2 0.43 wt.%, P2O5 0.34 wt.%, with the balance being other impurities.

[0038] In the following embodiments, the composition of the graphite tailings powder is as follows: SiO2 0.31wt.%, Al2O3 0.28wt.%, K2O 0.04wt.%, Fe2O3 0.14wt.%, CaO 96.91wt.%, MgO 0.28wt.%, P2O5 0.02wt.%, with the balance being other impurities.

[0039] In the following examples, the composition of the red mud powder is as follows: SiO2 17.60 wt.%, Al2O3 21.72 wt.%, Na2O 14.98 wt.%, K2O 0.14 wt.%, Fe2O3 35.14 wt.%, CaO 3.94 wt.%, MgO 0.13 wt.%, TiO2 5.11 wt.%, with the balance being other impurities.

[0040] Example 1: A preparation process for a solid waste-based high-strength foamed ceramic building material, comprising the following steps: (1) Short-cut rock wool fibers with a length distribution between 3 and 8 mm were mixed with a 2 mol / L sodium hydroxide solution at a ratio of 1 g: 15 mL, and then continuously stirred for 7.5 hours. After completion, the fibers were filtered out and dried to obtain pretreated fibers. Then, the pretreated fibers were added to Ca... 2+ Source (calcium nitrate), Mg 2+ Source (magnesium nitrate), Al 3+ In the mixture formed from the source (aluminum nitrate), the ratio of the pretreated fiber to the mixture is 1g:40mL, and the Ca in the mixture... 2+ Mg 2+ Al 3+ The molar ratio of sodium carbonate solution and sodium hydroxide solution is 1:2:1. Then, under stirring conditions, a composite alkaline solution formed by sodium carbonate solution and sodium hydroxide solution in a molar ratio of 3:1 is added dropwise to the mixture, and the pH of the system is controlled at 10±0.5 during this process. After complete precipitation, a mixed reaction system is obtained.

[0041] (2) The mixed reaction system is transferred to a reaction vessel and then heated to 140°C for hydrothermal reaction for 8.5 hours. After completion, the fibers are filtered out and then dried in an oven at 80°C to remove moisture, thus obtaining the strength reinforcing agent (e.g. Figure 1 (As shown).

[0042] (3) Take the following raw materials in the following proportions: 60 parts by weight of granite sawdust, 14 parts by weight of graphite tailings powder, 3.5 parts by weight of Bayer red mud powder, 1.2 parts by weight of magnesium carbonate powder, and 3.5 parts by weight of the strength enhancer of this embodiment. Mix the above raw materials, add water and stir evenly to make a wet material, then pour it into a mold to form it, and then place the obtained green body on corundum heat-resistant bricks and transfer it to an electric resistance furnace for sintering treatment: the heating rate is 10℃ / min, the sintering temperature is 1130℃, and the time is 30min. After completion, cool to room temperature to obtain foamed ceramics.

[0043] (4) Place the foamed ceramic in a 25% potassium dihydrogen phosphate solution and let it stand for 15 hours. After that, remove the foamed ceramic and let it dry to obtain foamed ceramic building materials (such as...). Figure 2 (As shown).

[0044] Performance testing: The compressive strength and flexural strength of the foamed ceramic building material prepared in this embodiment were tested according to the "Test Methods for Inorganic Rigid Thermal Insulation Products" (GB / T 5486-2008). The results were: compressive strength = 12.74 MPa, flexural strength = 7.38 MPa.

[0045] Example 2: A preparation process for a solid waste-based high-strength foamed ceramic building material, comprising the following steps: (1) Short-cut rock wool fibers with a length distribution between 3 and 8 mm were mixed with a 1.5 mol / L sodium hydroxide solution at a ratio of 1 g: 20 mL, and then continuously stirred for 6 hours. After completion, the fibers were filtered out and dried to obtain pretreated fibers. Then, the pretreated fibers were added to Ca... 2+ Source (calcium nitrate), Mg 2+ Source (magnesium nitrate), Al 3+ In the mixture formed from the source (aluminum nitrate), the ratio of the pretreated fiber to the mixture is 1g:30mL, and the Ca in the mixture... 2+ Mg 2+ Al 3+ The molar ratio of sodium carbonate solution and sodium hydroxide solution is 1:2:0.75. Then, under stirring conditions, a composite alkaline solution formed by sodium carbonate solution and sodium hydroxide solution in a molar ratio of 2.5:1 is added dropwise to the mixture, and the pH of the system is controlled at 10.5±0.5 during this process. After precipitation is complete, a mixed reaction system is obtained.

[0046] (2) The mixed reaction system is transferred to a reaction vessel and then heated to 160°C for hydrothermal reaction for 8 hours. After completion, the fibers are filtered out and then dried in an oven at 80°C to remove moisture, thus obtaining the strength reinforcing agent (e.g. Figure 3 (As shown).

[0047] (3) Take the following raw materials in the following proportions: 55 parts by weight of granite sawdust, 10 parts by weight of graphite tailings powder, 3 parts by weight of Bayer red mud powder, 0.8 parts by weight of magnesium carbonate powder, and 2.5 parts by weight of the strength enhancer of this embodiment. Mix the above raw materials, add water and stir evenly to make a wet material, then pour it into a mold to form it, and then place the obtained green body on corundum heat-resistant bricks and transfer it to an electric resistance furnace for sintering treatment: the heating rate is 5℃ / min, the sintering temperature is 1080℃, and the time is 40min. After completion, cool to room temperature to obtain foamed ceramics.

[0048] (4) Place the foamed ceramic in a 30% potassium dihydrogen phosphate solution and let it stand for 12 hours. After that, remove the foamed ceramic and let it dry to obtain foamed ceramic building materials (such as...). Figure 4 (As shown).

[0049] Performance testing: The compressive strength and flexural strength of the foamed ceramic building material prepared in this embodiment were tested using the same method as in Example 1 above. The results were: compressive strength = 12.27 MPa, flexural strength = 7.06 MPa.

[0050] Example 3: A preparation process for a solid waste-based high-strength foamed ceramic building material, comprising the following steps: (1) Short-cut rock wool fibers with a length distribution between 3 and 8 mm were mixed with a 3 mol / L sodium hydroxide solution at a ratio of 1 g: 10 mL, and then continuously stirred for 8 hours. After completion, the fibers were filtered out and dried to obtain pretreated fibers. Then, the pretreated fibers were added to Ca... 2+ Source (calcium chloride), Mg 2+ Source (magnesium chloride), Al 3+ In the mixture formed by the source (aluminum chloride), the ratio of the pretreated fiber to the mixture is 1g:50mL, and the Ca in the mixture... 2+ Mg 2+ Al 3+ The molar ratio of potassium carbonate solution and sodium hydroxide solution is 1:2:1.5. Then, under stirring conditions, a composite alkaline solution formed by potassium carbonate solution and sodium hydroxide solution in a molar ratio of 2:1 is added dropwise to the mixture, and the pH of the system is controlled at 10±0.5 during this process. After complete precipitation, a mixed reaction system is obtained.

[0051] (2) The mixed reaction system is transferred to a reaction vessel and then heated to 120°C for hydrothermal reaction for 10 hours. After completion, the fibers are filtered out and then dried in an oven at 80°C to remove moisture, thus obtaining the strength reinforcing agent (e.g. Figure 5 (As shown).

[0052] (3) Take the following raw materials in the following proportions: 68 parts by weight of granite sawdust, 20 parts by weight of graphite tailings powder, 4 parts by weight of Bayer red mud powder, 1.5 parts by weight of magnesium carbonate powder, and 2 parts by weight of the strength enhancer of this embodiment. Mix the above raw materials, add water and stir evenly to make a wet material, then pour it into a mold to form it, and then place the obtained green body on corundum heat-resistant bricks and transfer it to an electric resistance furnace for sintering treatment: the heating rate is 10℃ / min, the sintering temperature is 1150℃, and the time is 20min. After completion, cool to room temperature to obtain foamed ceramics.

[0053] (4) Place the foamed ceramic in a 20% potassium dihydrogen phosphate solution and let it stand for 18 hours. After that, remove the foamed ceramic and let it dry to obtain foamed ceramic building materials (such as...). Figure 6 (As shown).

[0054] Performance testing: The compressive strength and flexural strength of the foamed ceramic building material prepared in this embodiment were tested using the same method as in Example 1 above. The results were: compressive strength = 11.98 MPa, flexural strength = 6.72 MPa.

[0055] Example 4: A preparation process for a solid waste-based high-strength foamed ceramic building material, comprising the following steps: (1) Take the following raw materials in the following proportions: 60 parts by weight of granite sawdust, 14 parts by weight of graphite tailings powder, 3.5 parts by weight of Bayer red mud powder, 1.2 parts by weight of magnesium carbonate powder, and 7.5 parts by weight of short-cut rock wool fibers with a length distribution between 3 and 8 mm. Mix the above raw materials, add water and stir evenly to make a wet material, then pour it into a mold to form it. Place the resulting green body on corundum heat-resistant bricks and transfer it to an electric resistance furnace for sintering: the heating rate is 10℃ / min, the sintering temperature is 1130℃, and the time is 30min. After completion, cool to room temperature to obtain foamed ceramics.

[0056] (4) Place the foamed ceramic in a 25% potassium dihydrogen phosphate solution and let it stand for 15 hours. After that, remove the foamed ceramic and let it dry to obtain foamed ceramic building materials (such as...). Figure 7 (As shown).

[0057] Performance testing: The compressive strength and flexural strength of the foamed ceramic building material prepared in this embodiment were tested using the same method as in Example 1 above. The results were: compressive strength = 10.23 MPa, flexural strength = 6.17 MPa.

[0058] Example 5: A preparation process for a solid waste-based high-strength foamed ceramic building material, comprising the following steps: The following raw materials were prepared in the following proportions: 60 parts by weight of granite sawdust, 14 parts by weight of graphite tailings powder, 3.5 parts by weight of Bayer process red mud powder, 1.2 parts by weight of magnesium carbonate powder, and 3.5 parts by weight of the strength enhancer prepared in Example 1 above. The above raw materials were mixed, water was added, and the mixture was stirred evenly to form a wet material. This wet material was then poured into a mold for shaping. The resulting green body was placed on corundum heat-resistant bricks and transferred to a resistance furnace for sintering: the heating rate was 10℃ / min, the sintering temperature was 1130℃, and the time was 30min. After sintering, the material was cooled to room temperature to obtain foamed ceramic building materials (such as...). Figure 8 (As shown).

[0059] Performance testing: The compressive strength and flexural strength of the foamed ceramic building material prepared in this embodiment were tested using the same method as in Example 1 above. The results were: compressive strength = 8.92 MPa, flexural strength = 5.49 MPa.

[0060] Example 6: A preparation process for a solid waste-based high-strength foamed ceramic building material, comprising the following steps: (1) Short-cut rock wool fibers with a length distribution between 3 and 8 mm were mixed with a 1.5 mol / L sodium hydroxide solution at a ratio of 1 g: 20 mL, and then stirred continuously for 6 hours. After completion, the fibers were filtered out and dried to obtain a strength enhancer (such as...). Figure 9 (As shown).

[0061] (2) Take the following raw materials in the following proportions: 55 parts by weight of granite sawdust, 10 parts by weight of graphite tailings powder, 3 parts by weight of Bayer red mud powder, 0.8 parts by weight of magnesium carbonate powder, and 2.5 parts by weight of the strength enhancer of this embodiment. Mix the above raw materials, add water and stir evenly to make a wet material, then pour it into a mold to form it, and then place the obtained green body on corundum heat-resistant bricks and transfer it to an electric resistance furnace for sintering treatment: the heating rate is 5℃ / min, the sintering temperature is 1080℃, and the time is 40min. After completion, cool to room temperature to obtain foamed ceramics.

[0062] (3) Place the foamed ceramic in a 30% potassium dihydrogen phosphate solution and let it stand for 12 hours. After that, remove the foamed ceramic and let it dry to obtain foamed ceramic building materials (such as...). Figure 10 (As shown).

[0063] Performance testing: The compressive strength and flexural strength of the foamed ceramic building material prepared in this embodiment were tested using the same method as in Example 1 above. The results were: compressive strength = 10.31 MPa, flexural strength = 6.42 MPa.

[0064] Example 7: A preparation process for a solid waste-based high-strength foamed ceramic building material, comprising the following steps: (1) Add short-cut rock wool fibers with a length distribution between 3 and 8 mm to Ca 2+ Source (calcium chloride), Mg 2+ Source (magnesium chloride), Al 3+ In the mixture formed by the source (aluminum chloride), the ratio of the pretreated fiber to the mixture is 1g:50mL, and the Ca in the mixture... 2+ Mg 2+ Al 3+ The molar ratio of potassium carbonate solution and sodium hydroxide solution is 1:2:1.5. Then, under stirring conditions, a composite alkaline solution formed by potassium carbonate solution and sodium hydroxide solution in a molar ratio of 2:1 is added dropwise to the mixture, and the pH of the system is controlled at 10±0.5 during this process. After complete precipitation, a mixed reaction system is obtained.

[0065] (2) The mixed reaction system is transferred to a reaction vessel and then heated to 120°C for hydrothermal reaction for 10 hours. After completion, the fibers are filtered out and then dried in an oven at 80°C to remove moisture, thus obtaining the strength reinforcing agent (e.g. Figure 11 (As shown).

[0066] (3) Take the following raw materials in the following proportions: 68 parts by weight of granite sawdust, 20 parts by weight of graphite tailings powder, 4 parts by weight of Bayer red mud powder, 1.5 parts by weight of magnesium carbonate powder, and 2 parts by weight of the strength enhancer of this embodiment. Mix the above raw materials, add water and stir evenly to make a wet material, then pour it into a mold to form it, and then place the obtained green body on corundum heat-resistant bricks and transfer it to an electric resistance furnace for sintering treatment: the heating rate is 10℃ / min, the sintering temperature is 1150℃, and the time is 20min. After completion, cool to room temperature to obtain foamed ceramics.

[0067] (4) Place the foamed ceramic in a 20% potassium dihydrogen phosphate solution and let it stand for 18 hours. After that, remove the foamed ceramic and let it dry to obtain foamed ceramic building materials (such as...). Figure 12 (As shown).

[0068] Performance testing: The compressive strength and flexural strength of the foamed ceramic building material prepared in this embodiment were tested using the same method as in Example 1 above. The results were: compressive strength = 10.14 MPa, flexural strength = 5.76 MPa.

[0069] Example 8: A preparation process for a solid waste-based high-strength foamed ceramic building material, comprising the following steps: (1) Take the following raw materials in the following proportions: 55 parts by weight of granite sawdust, 10 parts by weight of graphite tailings powder, 3 parts by weight of Bayer red mud powder, 0.25 parts by weight of silicon carbide powder, and 2.5 parts by weight of the strength enhancer prepared in Example 2 above. Mix the above raw materials, add water and stir evenly to make a wet material, then pour it into a mold to form it, and then place the obtained green body on corundum heat-resistant bricks and transfer it to an electric resistance furnace for sintering treatment: the heating rate is 5℃ / min, the sintering temperature is 1080℃, and the time is 40min. After completion, cool to room temperature to obtain foamed ceramics.

[0070] (2) Place the foamed ceramic in a 30% potassium dihydrogen phosphate solution and let it stand for 12 hours. After that, remove the foamed ceramic and let it dry to obtain foamed ceramic building materials (such as...). Figure 13 (As shown).

[0071] Performance testing: The compressive strength and flexural strength of the foamed ceramic building material prepared in this embodiment were tested using the same method as in Example 1 above. The results were: compressive strength = 10.06 MPa, flexural strength = 6.03 MPa.

[0072] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., should be included within the protection scope of the present invention.

Claims

1. A preparation process for a solid waste-based high-strength foamed ceramic building material, characterized in that, Includes the following steps: (1) The chopped rock wool fibers were placed in an alkaline solution and stirred. After the reaction was completed, the pretreated fibers were mixed with Ca... 2+ Source, Mg 2+ Source, Al 3+ The source solution is mixed, and then a composite alkaline solution formed by carbonate and alkaline solution is added dropwise under stirring until precipitation is complete, to obtain a mixed reaction system for later use; (2) The mixed reaction system is subjected to hydrothermal reaction. After the reaction is completed, the fibers are separated and dried to obtain the strength enhancer for later use. (3) Using 55-68 parts by weight of granite sawdust, 10-20 parts by weight of graphite tailings powder, 3-4 parts by weight of red mud powder, 0.8-1.5 parts by weight of magnesium carbonate powder, and 2-3.5 parts by weight of strength enhancer as raw materials, the mixture is sintered and then cooled to room temperature to obtain foamed ceramics; then the foamed ceramics are placed in potassium dihydrogen phosphate solution and left to stand, and the foamed ceramic building material is obtained after the process is completed. In step (1), the Ca 2+ Source, Mg 2+ Source, Al 3+ The Ca provided by the source 2+ Mg 2+ Al 3+ The molar ratio is 1:2:0.75~1.5; In step (1), the pH of the system is controlled between 9.5 and 11 by adding the composite alkaline solution dropwise; In step (2), the temperature of the hydrothermal reaction is 120~160℃ and the time is 8~10 hours; In step (3), the sintering temperature is 1080~1150℃ and the time is 20~40min.

2. The preparation process of the solid waste-based high-strength foamed ceramic building material according to claim 1, characterized in that, In step (1), the ratio of the chopped rock wool fiber to the alkaline solution is 1g: 10~20mL; Alternatively, in step (1), the length of the chopped rock wool fiber is 3~8mm; Alternatively, in step (1), the concentration of the alkaline solution is 1.5~3 mol / L.

3. The preparation process of the solid waste-based high-strength foamed ceramic building material according to claim 1, characterized in that, In step (1), the alkaline solution is selected from at least one of sodium hydroxide and potassium hydroxide solution; or, in step (1), the stirring time is 6 to 8 hours.

4. The preparation process of the solid waste-based high-strength foamed ceramic building material according to claim 1, characterized in that, In step (1), the pretreated fiber contains Ca 2+ Source, Mg 2+ Source, Al 3+ The solution ratio of the source is 1g: 30~50mL.

5. The preparation process of the solid waste-based high-strength foamed ceramic building material according to claim 1, characterized in that, In step (1), the Ca 2+ The source includes at least one of calcium chloride and calcium nitrate; Alternatively, in step (1), the Mg 2+ The sources include at least one of magnesium chloride and magnesium nitrate; Alternatively, in step (1), the Al 3+ The source includes at least one of aluminum chloride and aluminum nitrate; Alternatively, in step (1), the carbonate includes at least one of sodium carbonate, potassium carbonate, and ammonium carbonate; Alternatively, in step (1), the alkaline solution may include at least one of sodium hydroxide and potassium hydroxide solution.

6. The preparation process of the solid waste-based high-strength foamed ceramic building material according to claim 1, characterized in that, In step (1), the molar ratio of carbonate to alkali in the composite alkali solution is 2~3:

1.

7. The preparation process of the solid waste-based high-strength foamed ceramic building material according to any one of claims 1-6, characterized in that, In step (3), the mass fraction of the potassium dihydrogen phosphate solution is 20-30%; or, in step (3), the standing time is 12-18 hours.

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