High-strength thermal insulation rock wool board and preparation method thereof

Abstract

The invention belongs to the technical field of rock wool thermal insulation materials, and particularly relates to a high-strength thermal insulation rock wool board and a preparation method thereof. The high-strength thermal insulation rock wool board is prepared from the following raw materials in parts by weight: 65 to 72 parts of basalt, 10 to 15 parts of dolomite, 8 to 12 parts of iron ore, 3 to 8 parts of bauxite, 2 to 5 parts of limestone, 10 to 15 parts of aerogel powder and 4 to 7 parts of binder. The aerogel powder is prepared by the following preparation processes: mixing tetraethoxysilane, ethanol and water, adjusting the pH value to 2.5-4, and stirring under a heating condition to obtain silicon dioxide sol; the preparation method comprises the following steps: dispersing black phosphorene in water to obtain black phosphorene dispersion liquid; and mixing a black phosphorene dispersion liquid with the silicon dioxide sol to form a mixed solution, adjusting the pH value of the mixed solution to 8-10, standing, aging, freeze-drying and grinding to obtain the aerogel powder. The high-strength heat-preservation rock wool board has the advantages of low heat conductivity, low water absorption and excellent mechanical strength.

Description

Technical Field

[0001] The present invention belongs to the technical field of rock wool thermal insulation materials, and in particular relates to a high-strength thermal insulation rock wool board and a preparation method thereof. Background Art

[0002] In the field of building materials, using wall insulation materials that offer sound insulation, heat insulation, and cold protection can improve wall insulation performance and reduce the amount of wall materials used, making it an excellent choice for achieving environmental protection and energy conservation. Wall insulation materials can be divided into inorganic and organic insulation materials. Organic materials have poor fire resistance and release toxic gases during combustion, posing a significant public safety risk. Inorganic insulation materials, primarily vitrified microspheres, rock wool, and glass wool, offer advantages such as corrosion resistance and non-combustibility, improving the overall fire resistance of a building.

[0003] As a representative inorganic insulation material, rock wool board boasts advantages such as being non-flammable, non-toxic, and widely applicable, and has been used to some extent in energy-saving building renovations. However, rock wool board's inherent performance flaws are also quite significant, and its practical application presents numerous challenges that cannot be ignored. First, as an insulation material, rock wool's thermal conductivity needs to be further reduced to improve its insulation performance. Second, rock wool board is primarily produced by pendulum pressing, resulting in numerous cavities between its internal fibers, making it virtually invulnerable to water erosion. Once contaminated with water, its insulation performance and structural stability deteriorate. Furthermore, rock wool suffers from poor dimensional stability and low tensile strength, making it susceptible to structural damage from a variety of factors in practical applications. Summary of the Invention

[0004] The first object of the present invention is to provide a high-strength thermal insulation rock wool board, which has low thermal conductivity, low water absorption and excellent mechanical strength.

[0005] The second object of the present invention is to provide a method for preparing the above-mentioned high-strength thermal insulation rock wool board.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is: A high-strength thermal insulation rock wool board, comprising the following raw materials in parts by weight: 65-72 parts of basalt, 10-15 parts of dolomite, 8-12 parts of iron ore, 3-8 parts of bauxite, 2-5 parts of limestone, 10-15 parts of aerogel powder, and 4-7 parts of a binder; The aerogel powder is prepared by the following preparation process: (1) Mixing ethyl orthosilicate, ethanol and water, adjusting the pH to 2.5-4, and stirring under heating to obtain silica sol; (2) dispersing black phosphorene in water to obtain a black phosphorene dispersion; mixing the black phosphorene dispersion with the silica sol to form a mixed solution, adjusting the pH of the mixed solution to 8-10, allowing the mixed solution to stand for aging, freeze-drying, and grinding to obtain the aerogel powder.

[0007] Furthermore, in step (1), the volume ratio of ethyl orthosilicate, ethanol and water is 1:(3-5):(1-2), the heating temperature is 50-70° C., and the stirring time is 1-3 h.

[0008] Furthermore, in step (2), the ratio of the amount of black phosphorene to water is 1 g: 80-120 mL; and the volume ratio of the black phosphorene dispersion to the silica sol is 1:3.5-6.

[0009] Furthermore, the binder is prepared by the following preparation process: Silicon dioxide, aluminum oxide, titanium dioxide, zinc oxide, and gadolinium oxide are uniformly mixed, heated to melt, quenched, and crushed to obtain glass powder; the glass powder is nitrided to obtain nitrided glass powder; sodium silicate is added to water and stirred to dissolve, and the nitrided glass powder is then added, and the adhesive is obtained after ultrasonic treatment, standing, and defoaming.

[0010] Furthermore, the mass ratio of the silicon dioxide, aluminum oxide, titanium dioxide, zinc oxide, and gadolinium oxide is 1: (0.5-0.8): (0.2-0.4): (0.2-0.3): (0.1-0.2); and the heating and melting temperature is 1100-1300°C.

[0011] Furthermore, the operation of the nitriding treatment is: introducing ammonia gas into the glass powder for nitriding; the flow rate of the ammonia gas is 100-150 mL / min; the temperature of the nitriding treatment is 700-1000° C., and the time is 3-6 hours.

[0012] Furthermore, the temperature of the stirring and dissolving is 40-50° C.; and the mass ratio of the sodium silicate to the nitride glass powder is 1:0.05-0.1.

[0013] The method for preparing the high-strength thermal insulation rock wool board comprises the following steps: (a) uniformly mixing basalt, dolomite, iron ore, bauxite and limestone in the aforementioned proportions by weight, heating and melting the mixture, centrifuging the mixture and stretching and guiding the mixture to obtain rock wool fibers; (b) The rock wool fibers are settled by negative pressure suction to form a primary rock wool tape, a binder and aerogel powder are sprayed on the primary rock wool tape, and then the primary rock wool tape is fed into a pendulum machine for folding to obtain a primary rock wool layer; the primary rock wool layer is pre-pressed and heated and cured to obtain the rock wool board.

[0014] Furthermore, the temperature of the heating and melting in step (a) is 1450-1550° C.; the pressure of the pre-pressing in step (b) is 0.2-0.3 MPa; the temperature of the heating and curing is 200-300° C., and the time is 20-25 minutes.

[0015] The beneficial technical effects of the present invention are: 1. The present invention adds black phosphorene-silica composite aerogel to the rock wool board, which can simultaneously improve the mechanical properties and thermal insulation properties of the rock wool board and enhance the hydrophobicity of the rock wool board. Silica aerogel has a special nano-network structure, and has the advantages of low density, large specific surface area, stable chemical properties, low thermal conductivity, and strong hydrophobicity. Adding it to the rock wool board can improve the durability and thermal insulation of the rock wool board. During the pendulum-type cotton spreading process, the present invention evenly sprays the aerogel powder on the fiber surface. Under the action of the binder, the aerogel powder clings to the surface of the rock wool fiber and the pores formed by the intersection of the fibers to form a uniform complex. The black phosphorene in the aerogel powder acts as a nano-reinforcement phase, which can disperse stress, hinder crack propagation, improve the strength of the aerogel, and thus improve the mechanical properties of the rock wool board.

[0016] 2. This invention adds nitrided glass powder to sodium silicate as a binder. Glass powder exhibits high-temperature stability, and its addition to the binder enhances the thermal stability of the sodium silicate, thereby strengthening the rock wool board's fire resistance. It also increases the board's strength and enhances its structural stability. Surface nitriding of the glass powder forms more dense Si3N4, AlN, TiN, and other phases on its surface, increasing the contact angle between the glass powder and water, reducing surface defects, and lowering its surface energy. This shortens the water molecule permeation path, reduces water adsorption, enhances the binder's hydrophobicity, and improves the durability of the rock wool board. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a scanning electron microscope image of the aerogel powder prepared in Example 1 of the present invention; Figure 2 This is a scanning electron microscope image of the adhesive prepared in Example 1 of the present invention after curing. DETAILED DESCRIPTION

[0018] The following is a further detailed description of the present invention in conjunction with specific preferred embodiments, and it is not intended that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art of the present invention, without departing from the inventive concept, several simple deductions or replacements can also be made, all of which should be considered to belong to the scope of protection of the present invention. The specific conditions not indicated in the examples are carried out according to conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used, unless otherwise specified, are conventional products obtained through commercial channels.

[0019] (1) Implementation Example 1 Example 1 provides a high-strength thermal insulation rock wool board, which is composed of the following raw materials in parts by weight: 70 parts of basalt, 12 parts of dolomite, 10 parts of iron ore, 5 parts of bauxite, 3 parts of limestone, 12 parts of aerogel powder, and 5 parts of binder; The aerogel powder is prepared by the following preparation process: (1) Ethyl orthosilicate, ethanol, and water were mixed uniformly in a volume ratio of 1:4:2, the pH was adjusted to 3 using 0.2 mol / L nitric acid, and then stirred at 60°C for 2 h to obtain a silica sol; (2) Add black phosphorene to deionized water at a dosage ratio of 1 g:100 mL, and ultrasonically disperse in an ice-water bath for 30 min to obtain a black phosphorene dispersion; stir and mix the black phosphorene dispersion with the above-mentioned silica sol at a volume ratio of 1:5, then add 25% ammonia water to adjust the pH to 9, let it stand for 30 h, freeze-dry, and grind to obtain aerogel powder; the scanning electron microscope image of the aerogel powder is shown in FIG. Figure 1 shown.

[0020] The above-mentioned adhesive is prepared by the following preparation process: Silicon dioxide, aluminum oxide, titanium dioxide, zinc oxide, and gadolinium oxide were uniformly mixed in a mass ratio of 1:0.6:0.3:0.2:0.2, heated and melted at 1200°C, and crushed after quenching to obtain glass powder; the glass powder was placed in a nitriding furnace, and ammonia gas was introduced at a gas flow rate of 120 mL / min, and reacted at 800°C for 5 hours to obtain nitrided glass powder; sodium silicate was first added to deionized water in a mass ratio of sodium silicate, nitrided glass powder, and deionized water of 1:0.08:1.7, heated and stirred at 40°C until dissolved, and then nitrided glass powder was added and ultrasonically dispersed, and the binder was obtained after standing and defoaming; the scanning electron microscope image of the binder after curing is as shown below Figure 2 shown.

[0021] This embodiment also provides a method for preparing the above-mentioned high-strength thermal insulation rock wool board, and the specific steps are as follows: (a) basalt, dolomite, iron ore, bauxite and limestone are mixed uniformly according to the above-mentioned parts by weight, melted at 1500° C., centrifuged at 5000 rpm and stretched to obtain rock wool fibers with a diameter of 4-9 μm; (b) The rock wool fibers were deposited on a conveyor belt by negative pressure suction, and a binder and aerogel powder were sprayed on the rock wool fibers. The rock wool fibers were folded layer by layer by a pendulum method on a conveyor belt with a frequency of 110 times / min to obtain a primary rock wool layer. The primary rock wool layer was pre-pressed with a pressure of 0.2 MPa and then cured at 250°C for 20 min to obtain a rock wool board.

[0022] Example 2 Example 2 provides a high-strength thermal insulation rock wool board, which is composed of the following raw materials in parts by weight: 65 parts of basalt, 10 parts of dolomite, 8 parts of iron ore, 3 parts of bauxite, 2 parts of limestone, 10 parts of aerogel powder, and 4 parts of binder; The aerogel powder is prepared by the following preparation process: (1) Ethyl orthosilicate, ethanol, and water were mixed uniformly in a volume ratio of 1:3:1, the pH was adjusted to 2.5 using 0.1 mol / L nitric acid, and then stirred at 50°C for 1 h to obtain a silica sol; (2) Add black phosphorene to deionized water at a ratio of 1 g:80 mL, and ultrasonically disperse in an ice-water bath for 20 min to obtain a black phosphorene dispersion; stir and mix the black phosphorene dispersion with the above-mentioned silica sol at a volume ratio of 1:3.5, then add 25% ammonia water to adjust the pH to 8, let it stand for 20 h, freeze-dry, and grind to obtain aerogel powder; The above-mentioned adhesive is prepared by the following preparation process: Silicon dioxide, aluminum oxide, titanium dioxide, zinc oxide, and gadolinium oxide are uniformly mixed in a mass ratio of 1:0.5:0.2:0.2:0.1, heated and melted at 1100°C, quenched, and crushed to obtain glass powder; the glass powder is placed in a nitriding furnace, ammonia is introduced at a gas flow rate of 100 mL / min, and reacted at 700°C for 3 hours to obtain nitrided glass powder; sodium silicate is first added to deionized water in a mass ratio of sodium silicate, nitrided glass powder, and deionized water of 1:0.05:1.5, heated and stirred at 40°C until dissolved, and then the nitrided glass powder is added and ultrasonically dispersed, and the binder is obtained after standing and defoaming.

[0023] This embodiment also provides a method for preparing the above-mentioned high-strength thermal insulation rock wool board, and the specific steps are as follows: (a) basalt, dolomite, iron ore, bauxite and limestone are mixed uniformly according to the above-mentioned parts by weight, melted at 1450° C., centrifuged at 4500 rpm and stretched to obtain rock wool fibers with a diameter of 4-9 μm; (b) The rock wool fibers were deposited on a conveyor belt by negative pressure suction, and a binder and aerogel powder were sprayed on the rock wool fibers. The rock wool fibers were folded layer by layer by a pendulum method on a conveyor belt at a frequency of 100 times / min to obtain a primary rock wool layer. The primary rock wool layer was pre-pressed with a pressure of 0.2 MPa and then cured at 200°C for 20 min to obtain a rock wool board.

[0024] Example 3 Example 3 provides a high-strength thermal insulation rock wool board, which is composed of the following raw materials in parts by weight: 72 parts of basalt, 15 parts of dolomite, 12 parts of iron ore, 8 parts of bauxite, 5 parts of limestone, 15 parts of aerogel powder, and 7 parts of binder; The aerogel powder is prepared by the following preparation process: (1) Ethyl orthosilicate, ethanol, and water were mixed uniformly in a volume ratio of 1:5:2, the pH was adjusted to 4 using 0.3 mol / L nitric acid, and then stirred at 70°C for 3 h to obtain a silica sol; (2) Black phosphorene was added to deionized water at a dosage ratio of 1 g:120 mL, and ultrasonically dispersed in an ice-water bath for 30 min to obtain a black phosphorene dispersion; the black phosphorene dispersion was stirred and mixed with the above-mentioned silica sol at a volume ratio of 1:6, and then 28% ammonia water was added to adjust the pH to 10. The mixture was allowed to stand for 40 h and then freeze-dried. The aerogel powder was obtained after grinding.

[0025] The above-mentioned adhesive is prepared by the following preparation process: Silicon dioxide, aluminum oxide, titanium dioxide, zinc oxide, and gadolinium oxide are uniformly mixed in a mass ratio of 1:0.8:0.4:0.3:0.2, heated to melt at 1300°C, quenched, and crushed to obtain glass powder; the glass powder is placed in a nitriding furnace, ammonia is introduced at a gas flow rate of 150 mL / min, and the mixture is reacted at 1000°C for 6 hours to obtain nitrided glass powder; sodium silicate is first added to deionized water in a mass ratio of sodium silicate, nitrided glass powder, and deionized water of 1:0.1:1.8, heated and stirred at 50°C until dissolved, and then the nitrided glass powder is added and ultrasonically dispersed, and the binder is obtained after standing for defoaming.

[0026] This embodiment also provides a method for preparing the above-mentioned high-strength thermal insulation rock wool board, and the specific steps are as follows: (a) basalt, dolomite, iron ore, bauxite and limestone are mixed uniformly according to the above-mentioned parts by weight, melted at 1550° C., centrifuged at 5500 rpm and stretched to obtain rock wool fibers with a diameter of 4-9 μm; (b) The rock wool fibers were deposited on a conveyor belt by negative pressure suction, and a binder and aerogel powder were sprayed on the rock wool fibers. The rock wool fibers were then folded layer by layer by a pendulum method on a conveyor belt with a frequency of 120 times / min to obtain a primary rock wool layer. The primary rock wool layer was pre-pressed with a pressure of 0.3 MPa and then cured at 300°C for 25 min to obtain a rock wool board.

[0027] (2) Comparative Example Comparative Example 1 Comparative Example 1 is substantially the same as Example 1, except that when preparing the aerogel powder, the black phosphorene dispersion in step (2) is omitted, and the remaining steps remain unchanged.

[0028] Comparative Example 2 Comparative Example 2 is substantially the same as Example 1, except that when preparing the binder, the nitride glass powder is omitted, and sodium silicate is used as the binder.

[0029] Comparative Example 3 Comparative Example 3 is substantially the same as Example 1, except that the glass powder is not nitrided when preparing the binder, that is, sodium silicate, glass powder and deionized water are mixed.

[0030] (3) Test examples 1. Mechanical Strength Test: According to the national standard GB / T 25975-2018 "Rock Wool Products for External Thermal Insulation of Building Exterior Walls", the tensile strength and compressive strength of the rock wool boards of Examples 1-3 and Comparative Examples 1-3 were tested; the test results are shown in Table 1.

[0031] 2. Water absorption test: GB / T 25975-2018 "Rockwool products for external thermal insulation of building exterior walls" was tested for water absorption properties of the rockwool boards of Examples 1-3 and Comparative Examples 1-4. The test results are shown in Table 1.

[0032] 3. Thermal Conductivity Test: According to the national standard GB / T 10294-2008 "Insulation materials - Determination of steady-state thermal resistance and related properties - Guarded hot plate method", the thermal conductivity of the rock wool boards of Examples 1-3 and Comparative Examples 1-4 was tested; the test results are shown in Table 1.

[0033] Table 1 Test results of mechanical, water absorption and thermal conductivity properties of rock wool board As can be seen from Table 1, the high-strength thermal insulation rock wool boards prepared in Examples 1-3 of the present invention have excellent structural stability, not only greatly reduced water absorption, but also low thermal conductivity, which helps to improve the thermal insulation effect.

[0034] Compared with Example 1, Comparative Example 1 omits the black phosphorene in step (2), Comparative Example 2 omits the nitride glass powder, and Comparative Example 3 replaces the nitride glass powder with glass powder. The mechanical properties, hydrophobicity and thermal insulation properties of Comparative Examples 1-3 all decrease to a certain extent. The above results show that: (1) The present invention adds black phosphorene-silica composite aerogel to the rock wool board, which can simultaneously improve the mechanical properties and thermal insulation properties of the rock wool board and enhance the hydrophobicity of the rock wool board. Silica aerogel has a special nano-network structure, so it has the advantages of low density, large specific surface area, stable chemical properties, low thermal conductivity, strong hydrophobicity, etc. Adding it to the rock wool board can improve the durability and thermal insulation of the rock wool board. In the pendulum-type cotton spreading process, the present invention evenly sprays the aerogel powder on the fiber surface. Under the action of the binder, the aerogel powder adheres to the surface of the rock wool fiber and the pores formed by the intersection of the fibers to form a uniform composite body. Black phosphorene in the aerogel powder acts as a nano-reinforcement phase, which can disperse stress, hinder crack propagation, improve the strength of the aerogel, and thus improve the mechanical properties of the rock wool board. (2) The present invention adds nitrided glass powder as a binder to sodium silicate, which can improve the strength and hydrophobicity of the rock wool board. Glass powder has high-temperature stability. Adding it to the binder can improve the thermal stability of sodium silicate, thereby enhancing the fire resistance of the rock wool board. At the same time, it can also improve the strength of the rock wool board and enhance the structural stability of the material. Surface nitriding treatment of the glass powder can form more dense Si3N4, AlN, TiN and other phases on its surface, increase the surface contact angle between the glass powder and water, reduce the surface defects of the glass powder, and reduce its surface energy, shorten the water molecule penetration path, reduce the adsorption capacity of water, enhance the hydrophobicity of the binder, and improve the durability of the rock wool board.

[0035] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the same. The basic principles and main features of the present invention have been described above using specific implementation schemes. Modifications or substitutions may be made based on the present invention, but such modifications or substitutions do not detract from the essence of the corresponding technical solutions from the scope of protection claimed by the present invention.

Claims

1. A high-strength thermal insulation rock wool board, characterized in that: The high-strength thermal insulation rock wool board is composed of the following raw materials in parts by weight: 65-72 parts of basalt, 10-15 parts of dolomite, 8-12 parts of iron ore, 3-8 parts of bauxite, 2-5 parts of limestone, 10-15 parts of aerogel powder, and 4-7 parts of binder; The aerogel powder is prepared by the following preparation process: (1) Mixing ethyl orthosilicate, ethanol and water, adjusting the pH to 2.5-4, and stirring under heating to obtain silica sol; (2) dispersing black phosphorene in water to obtain a black phosphorene dispersion; mixing the black phosphorene dispersion with the silica sol to form a mixed solution, adjusting the pH of the mixed solution to 8-10, allowing the mixed solution to stand for aging, freeze-drying, and grinding to obtain the aerogel powder.

2. The high-strength thermal insulation rock wool board according to claim 1, characterized in that: In step (1), the volume ratio of ethyl orthosilicate, ethanol and water is 1:(3-5):(1-2), the heating temperature is 50-70° C., and the stirring time is 1-3 h.

3. The high-strength thermal insulation rock wool board according to claim 1, characterized in that: In step (2), the ratio of black phosphorene to water is 1 g: 80-120 mL; and the volume ratio of the black phosphorene dispersion to the silica sol is 1:3.5-6.

4. The high-strength thermal insulation rock wool board according to claim 1, characterized in that: The binder is prepared by the following preparation process: Silicon dioxide, aluminum oxide, titanium dioxide, zinc oxide, and gadolinium oxide are uniformly mixed, heated to melt, quenched, and crushed to obtain glass powder; the glass powder is nitrided to obtain nitrided glass powder; sodium silicate is added to water and stirred to dissolve, and the nitrided glass powder is then added, and the adhesive is obtained after ultrasonic treatment, standing, and defoaming.

5. The high-strength thermal insulation rock wool board according to claim 4, characterized in that: The mass ratio of silicon dioxide, aluminum oxide, titanium dioxide, zinc oxide and gadolinium oxide is 1: (0.5-0.8): (0.2-0.4): (0.2-0.3): (0.1-0.2); the heating and melting temperature is 1100-1300°C.

6. The high-strength thermal insulation rock wool board according to claim 4, characterized in that: The operation of the nitriding treatment is as follows: introducing ammonia gas into the glass powder for nitriding; the flow rate of the ammonia gas is 100-150 mL / min; the temperature of the nitriding treatment is 700-1000° C., and the time is 3-6 hours.

7. The high-strength thermal insulation rock wool board according to claim 4, characterized in that: The stirring and dissolving temperature is 40-50° C.; the mass ratio of the sodium silicate to the nitride glass powder is 1:0.05-0.

1.

8. The method for preparing the high-strength thermal insulation rock wool board according to any one of claims 1 to 7, characterized in that: The following steps are involved: (a) uniformly mixing basalt, dolomite, iron ore, bauxite and limestone in the aforementioned proportions by weight, heating and melting the mixture, centrifuging the mixture and stretching and guiding the mixture to obtain rock wool fibers; (b) The rock wool fibers are settled by negative pressure suction to form a primary rock wool tape, a binder and aerogel powder are sprayed on the primary rock wool tape, and then the primary rock wool tape is fed into a pendulum machine for folding to obtain a primary rock wool layer; the primary rock wool layer is pre-pressed and heated and cured to obtain the rock wool board.

9. The method for preparing the high-strength thermal insulation rock wool board according to claim 8, characterized in that: The temperature of the heating and melting in step (a) is 1450-1550° C.; the pressure of the pre-pressing in step (b) is 0.2-0.3 MPa; the temperature of the heating and curing is 200-300° C., and the time is 20-25 minutes.

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