High-strength heat-resistant foam glass based on high-borosilicate

Abstract

This invention relates to the field of foam glass technology and discloses a high-strength, heat-resistant foam glass based on high borosilicate. This foam glass uses high borosilicate waste glass as the base material and zirconium dioxide modifier, titanium dioxide, composite foaming agent, and composite additives as auxiliary materials. It is formed through grinding and mixing, and a three-stage foaming and firing process. Through the synergistic design of the composite nucleating agent and the novel foaming system, the foaming temperature is significantly reduced while ensuring high performance. The introduction of a composite additive system maintains stable product performance while achieving a uniformly distributed color appearance. The three-stage temperature control process enables controllable growth and stabilization of the foam structure, overcoming the bottlenecks of uneven structure and high-temperature volatilization in traditional foam glass preparation. Finally, the overall optimization of the composition and process gives the product a longer service life and better mechanical strength under high-temperature conditions.

Description

Technical Field

[0001] This invention relates to the field of foam glass technology, and more specifically to a high-strength heat-resistant foam glass based on high borosilicate. Background Technology

[0002] With the increasing demands from the state for the resource utilization of industrial solid waste and the self-sufficiency of high-temperature insulation materials, the development of high-performance foam glass has become an important direction in the materials field. However, traditional foam glass often uses ordinary waste glass or borosilicate as raw materials, which has problems such as high foaming temperature, insufficient thermal stability, and limited mechanical properties.

[0003] Referring to existing patents, invention patent CN102101754B discloses a method for preparing boron-containing foam glass. Although it uses boron-containing waste glass and a nitrate foaming system, its foaming temperature is still maintained at 800–850℃, and it relies on the addition of multiple nitrates, resulting in high costs. Invention patent CN103553344B discloses a method for preparing borosilicate foam glass artificial floating island material, mainly focusing on artificial floating island applications. Its composition system and foaming agent selection are not suitable for high-temperature insulation scenarios. At the same time, as the application fields of foam glass expand to appearance-sensitive scenarios such as architectural decoration and solar energy utilization, existing coloring technologies have obvious defects. They often use excessive carbonaceous foaming agents, resulting in uneven color, easy graying, and problems such as decreased mechanical properties and high-temperature oxidation discoloration due to high residual carbon content. On the other hand, using transition metal oxides for coloring has limitations such as high cost and insufficient blackness.

[0004] Therefore, this invention proposes a method for preparing high-strength, high-heat-resistant foam glass with pure color, stable performance, and feasible process by using high borosilicate waste glass as the main body, introducing a composite nucleating agent, a composite additive system, and a low-temperature synergistic foaming system, combined with a segmented temperature-controlled foaming process. Summary of the Invention

[0005] In order to solve the problems mentioned in the background art, the object of the present invention is to provide a high-strength heat-resistant foam glass based on high borosilicate.

[0006] The objective of this invention can be achieved through the following technical solutions: A high-strength heat-resistant foam glass based on high borosilicate, comprising the following raw materials measured in parts by weight: 88-98 parts of high borosilicate waste glass, 0.5-1.5 parts of zirconium dioxide modifier, 0.5-1.5 parts of titanium dioxide, 0.4-7.8 parts of composite foaming agent, and 1.4-3.5 parts of composite additive.

[0007] As a further aspect of the present invention, the B2O3 content of the high borosilicate waste glass is not less than 15%.

[0008] As a further aspect of the present invention, the zirconium dioxide modified body is prepared by the following method: Step A: Disperse basalt fibers in an ethanol aqueous solution with a volume fraction of 50-60% to form a basalt fiber dispersion; add nano-zirconia to an ethanol aqueous solution with a volume fraction of 50-60% and sonicate until a uniform nano-zirconia dispersion is formed. Step B: Add N-(hydroxyethyl)-N,N-bis(trimethoxysilylpropyl)amine to the basalt fiber dispersion, stir and mix evenly, adjust the pH to 3-4, then raise the temperature to 60-70℃, keep it warm and stir for 4-6 hours, then add the nano-zirconia dispersion, continue stirring for 6-9 hours, stop heating, cool down and discharge the material, collect the solid material, wash and vacuum dry it to obtain the zirconia modified body.

[0009] It should be noted that in the above technical solution, N-(hydroxyethyl)-N,N-bis(trimethoxysilylpropyl)amine is used as a binder, and nano-zirconia is loaded onto the surface of basalt fiber through a condensation reaction to obtain basalt fiber loaded with nano-zirconia, i.e., zirconia modified body.

[0010] As a further embodiment of the present invention, the composite foaming agent is composed of 0.3-0.8 parts by weight of calcium carbide and 0.1-7 parts by weight of sodium fluorosilicate.

[0011] As a further embodiment of the present invention, the composite additive is composed of 1-2 parts by weight of Fe2O3, 0.1-0.5 parts by weight of CoO and 0.3-1 parts by weight of carbon black.

[0012] As a further aspect of the present invention, the method for preparing the foamed glass includes the following steps: Step 1: Weigh each ingredient according to the specified weight proportions and set aside. Step 2: First, wash and dry the high borosilicate waste glass, then place it in a ball mill jar for ball milling and sieve it. Next, mix it with zirconium dioxide modifier, titanium dioxide, composite foaming agent and composite additive, stir evenly, and continue to grind and sieve to obtain the synthetic material. Step 3: Place the synthetic material into the mold, then transfer the mold to the foaming furnace. After three-stage foaming and firing, stop heating and allow the material to cool to room temperature in the furnace before discharging.

[0013] As a further aspect of the present invention, in step two, the mesh size of the sieve is 80-100 mesh.

[0014] As a further aspect of the present invention, in step three, the specific method of the three-stage foaming firing is as follows: first, the temperature is raised to 450-500℃ at a heating rate of 8-15℃ / min and held for 20-40min; then, the temperature is raised to 750-780℃ at a heating rate of 5-8℃ / min and held for 15-35min; finally, the temperature is raised to 785-800℃ at a heating rate of 1-3℃ / min and held for 10-20min.

[0015] In the above technical solution, high borosilicate waste glass with a B2O3 content of not less than 15% is selected as the matrix material. Increasing the boron content helps to further reduce the coefficient of thermal expansion and enhance the stability of the network structure. Simultaneously, the zirconia-modified body has a supported structure; nano-zirconia can act as a nucleating agent, promoting the precipitation of microcrystalline phases from the glass phase during heat treatment, achieving efficient bonding between the glass and basalt fibers. The basalt fibers act as a skeleton, producing excellent support effects, thereby enhancing the mechanical strength of the foam glass. Furthermore, by introducing a composite additive system, the core performance of the material is ensured while achieving a pure color and appearance for the product.

[0016] Furthermore, this solution abandons the traditional single foaming agent of nitrates or carbon, and adopts a composite system of CaC2 and Na2SiF6. CaC2 decomposes during heating to release C2H2 gas, resulting in high foaming efficiency, while Na2SiF6, as a flux and foam stabilizer, effectively reduces the viscosity of the glass melt and slows gas escape. The synergistic effect of the two enables uniform closed-cell foaming at lower temperatures. This effectively overcomes the problems of high foaming temperature and uneven bubble structure associated with traditional foaming agents.

[0017] In addition, this solution proposes a gradient foaming process, namely a three-stage foaming and firing process of "low-temperature nucleation – medium-temperature foaming – high-temperature foam stabilization". The low-temperature foaming stage enables the composite nucleating agent to form uniformly distributed nuclei; the subsequent medium-temperature foaming reduces boron volatilization and energy consumption; and the final high-temperature stage stabilizes the bubble structure. This process achieves precise control of the foam structure by controlling the timing of nucleation and gas release, unlike the simple three-stage process of "preheating – foaming – annealing" in existing technologies.

[0018] The beneficial effects of this invention are: This invention enables foam glass with a density of 0.16–0.22 g / cm³. 3 The material exhibits a thermal conductivity ≤0.085 W / (m·K), a compressive strength ≥1.5MPa, and can be used for extended periods at 450℃ without structural degradation. These indicators are superior to existing patents, particularly showing significant improvements in strength and operating temperature. Furthermore, by using high-borosilicate waste glass and some fly ash as raw materials, this solution also offers advantages in solid waste resource utilization and low cost, aligning with the direction of green manufacturing.

[0019] Through the synergistic design of composite nucleating agents and novel foaming systems, the foaming temperature is significantly reduced while ensuring high performance. The product strength is enhanced by introducing zirconium dioxide modifiers. A three-stage temperature control process is adopted to achieve controllable growth and stabilization of the foam structure, breaking through the bottlenecks of structural inhomogeneity and high-temperature volatilization in traditional foam glass preparation. Finally, the overall optimization of composition and process enables the product to have a longer service life and better mechanical strength in high-temperature environments, expanding its application potential in special fields such as aerospace and high-temperature industrial furnace linings.

[0020] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Detailed Implementation

[0021] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1

[0022] A high-strength heat-resistant foam glass based on high borosilicate, comprising the following raw materials measured in parts by weight: 96.2 parts of high borosilicate waste glass, 1 part of zirconium dioxide modifier, 1 part of titanium dioxide, 0.3 parts of calcium carbide, 0.2 parts of sodium fluorosilicate, 1 part of Fe2O3, 0.3 parts of CoO, and 0.5 parts of carbon black.

[0023] The method for preparing the foamed glass includes the following steps: Step 1: Weigh each ingredient according to the specified weight proportions and set aside. Step 2: First, wash and dry the high borosilicate waste glass, then place it in a ball mill jar for ball milling and pass it through a 100-mesh sieve. Next, mix it with zirconium dioxide modifier, titanium dioxide, calcium carbide, sodium fluorosilicate, Fe2O3, CoO and carbon black. After stirring evenly, continue to grind and pass it through a 100-mesh sieve to obtain the synthetic material. Step 3: Place the synthetic material into the mold, then transfer the mold to the foaming furnace. First, raise the temperature to 480℃ at a heating rate of 10℃ / min and hold for 30 minutes. Then, raise the temperature to 760℃ at a heating rate of 5℃ / min and hold for 30 minutes. Finally, raise the temperature to 790℃ at a heating rate of 2℃ / min and hold for 15 minutes. After firing, stop heating and allow the material to cool to room temperature in the furnace before discharging.

[0024] The B2O3 content of high borosilicate waste glass shall not be less than 15%, and the same applies to the following.

[0025] The zirconium dioxide modified body was prepared using the following method: Step A: Disperse basalt fibers in a 50% (v / v) ethanol aqueous solution to form a 20% (w / w) basalt fiber dispersion; add nano-zirconia to a 50% (v / v) ethanol aqueous solution and sonicate until a uniform nano-zirconia dispersion is formed, with the mass fraction controlled at 10%. Step B: Add 0.6g of N-(hydroxyethyl)-N,N-bis(trimethoxysilylpropyl)amine to 10mL of basalt fiber dispersion, stir and mix evenly, adjust the pH to 3, then raise the temperature to 65℃, keep it warm and stir for 6h, then add 10mL of nano-zirconia dispersion, continue stirring for 8h, stop heating, cool down and discharge the material, collect the solid material, wash and vacuum dry it to obtain the zirconia modified body. Example 2

[0026] A high-strength heat-resistant foam glass based on high borosilicate, comprising the following raw materials measured in parts by weight: 95.7 parts of high borosilicate waste glass, 1.5 parts of zirconium dioxide modifier, 1 part of titanium dioxide, 0.4 parts of calcium carbide, 0.2 parts of sodium fluorosilicate, 1.5 parts of Fe2O3, 0.2 parts of CoO, and 0.5 parts of carbon black.

[0027] The method for preparing the foamed glass includes the following steps: Step 1: Weigh each ingredient according to the specified weight proportions and set aside. Step 2: First, wash and dry the high borosilicate waste glass, then place it in a ball mill jar for ball milling and pass it through a 100-mesh sieve. Next, mix it with zirconium dioxide modifier, titanium dioxide, calcium carbide, sodium fluorosilicate, Fe2O3, CoO and carbon black. After stirring evenly, continue to grind and pass it through a 100-mesh sieve to obtain the synthetic material. Step 3: Place the synthetic material into the mold, then transfer the mold to the foaming furnace. First, raise the temperature to 480℃ at a heating rate of 10℃ / min and hold for 30 minutes. Then, raise the temperature to 760℃ at a heating rate of 5℃ / min and hold for 30 minutes. Finally, raise the temperature to 790℃ at a heating rate of 2℃ / min and hold for 15 minutes. After firing, stop heating and allow the material to cool to room temperature in the furnace before discharging.

[0028] Comparative Example 1 A high-strength heat-resistant foam glass based on high borosilicate is different from Example 2 in that calcium carbide and sodium fluorosilicate are replaced with 0.6 parts by weight of calcium nitrate, while the rest are the same.

[0029] Comparative Example 2 A high-strength heat-resistant foam glass based on high borosilicate is different from Example 2 in that the foaming and firing process is adjusted to: the temperature is raised to 790°C at a heating rate of 10°C / min and held for 1 hour, while the rest are the same.

[0030] Comparative Example 3 A high-strength heat-resistant foam glass based on high borosilicate is different from Example 2 in that the zirconium dioxide modifier is replaced with nano-zirconium dioxide, while the rest are the same.

[0031] Test case According to standard JC / T 647-2014, the various properties of the foam glass in the examples and comparative examples were tested; This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of these embodiments are merely to aid in understanding the method and core ideas of the present invention, including the best mode, and to enable any person skilled in the art to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims. The scope of protection of this patent is defined by the claims and may include other embodiments that can be conceived by those skilled in the art. If these other embodiments have structural elements similar to those expressed in the claims, or if they include equivalent structural elements that are not substantially different from those expressed in the claims, then these other embodiments should also be included within the scope of the claims.

[0032] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-strength heat-resistant foam glass based on high borosilicate, characterized in that, Including the following raw materials measured in parts by weight: 88-98 parts of high borosilicate waste glass, 0.5-1.5 parts of zirconium dioxide modifier, 0.5-1.5 parts of titanium dioxide, 0.4-7.8 parts of composite foaming agent, and 1.4-3.5 parts of composite additive.

2. The high-strength heat-resistant foam glass based on high borosilicate according to claim 1, characterized in that, The B2O3 content of the high borosilicate waste glass is not less than 15%.

3. The high-strength heat-resistant foam glass based on high borosilicate according to claim 1, characterized in that, The zirconium dioxide modified body was prepared by the following method: Step A: Disperse basalt fibers in an ethanol aqueous solution with a volume fraction of 50-60% to form a basalt fiber dispersion; add nano-zirconia to an ethanol aqueous solution with a volume fraction of 50-60% and sonicate until a uniform nano-zirconia dispersion is formed. Step B: Add N-(hydroxyethyl)-N,N-bis(trimethoxysilylpropyl)amine to the basalt fiber dispersion, stir and mix evenly, adjust the pH to 3-4, then raise the temperature to 60-70℃, keep it warm and stir for 4-6 hours, then add the nano-zirconia dispersion, continue stirring for 6-9 hours, stop heating, cool down and discharge the material, collect the solid material, wash and vacuum dry it to obtain the zirconia modified body.

4. The high-strength heat-resistant foam glass based on high borosilicate according to claim 1, characterized in that, The composite foaming agent is composed of 0.3-0.8 parts by weight of calcium carbide and 0.1-7 parts by weight of sodium fluorosilicate.

5. The high-strength heat-resistant foam glass based on high borosilicate according to claim 1, characterized in that, The composite additive is composed of 1-2 parts by weight of Fe2O3, 0.1-0.5 parts by weight of CoO and 0.3-1 parts by weight of carbon black.

6. The high-strength heat-resistant foam glass based on high borosilicate according to claim 1, characterized in that, The method for preparing the foamed glass includes the following steps: Step 1: Weigh each ingredient according to the specified weight proportions and set aside. Step 2: First, wash and dry the high borosilicate waste glass, then place it in a ball mill jar for ball milling and sieve it. Next, mix it with zirconium dioxide modifier, titanium dioxide, composite foaming agent and composite additive, stir evenly, and continue to grind and sieve to obtain the synthetic material. Step 3: Place the synthetic material into the mold, then transfer the mold to the foaming furnace. After three-stage foaming and firing, stop heating and allow the material to cool to room temperature in the furnace before discharging.

7. A high-strength heat-resistant foam glass based on high borosilicate according to claim 6, characterized in that, In step two, the mesh size of the sieve is 80-100 mesh.

8. A high-strength heat-resistant foam glass based on high borosilicate according to claim 6, characterized in that, In step three, the specific method for the three-stage foaming firing is as follows: First, raise the temperature to 450-500℃ at a heating rate of 8-15℃ / min and hold for 20-40 minutes; then, raise the temperature to 750-780℃ at a heating rate of 5-8℃ / min and hold for 15-35 minutes; finally, raise the temperature to 785-800℃ at a heating rate of 1-3℃ / min and hold for 10-20 minutes.

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