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

Abstract

The application 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: basalt 65-72 parts, dolomite 10-15 parts, iron ore 8-12 parts, bauxite 3-8 parts, limestone 2-5 parts, aerogel powder 10-15 parts, and binder 4-7 parts. The aerogel powder is prepared by the following process: mixing tetraethyl orthosilicate, ethanol and water, adjusting the pH to 2.5-4, stirring under heating conditions to obtain a silica sol; dispersing black phosphorene in water to obtain a black phosphorene dispersion liquid; mixing the black phosphorene dispersion liquid with the silica sol to form a mixed liquid, adjusting the pH of the mixed liquid to 8-10, and then standing, aging, freeze-drying and grinding to obtain the aerogel powder. The high-strength thermal insulation rock wool board has low thermal conductivity, low water absorption and excellent mechanical strength.

Description

Technical Field

[0001] This invention belongs to the technical field of rock wool insulation materials, specifically relating to a high-strength insulation rock wool board and its preparation method. Background Technology

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

[0003] Rock wool boards, as a representative product of inorganic thermal insulation materials, have advantages such as being non-combustible, non-toxic, and widely applicable, and have been used to some extent in the energy-saving renovation of buildings. However, the performance defects of rock wool boards are also quite obvious, and there are many problems that cannot be ignored in practical applications. First, as an insulation material, the thermal conductivity of rock wool needs to be further reduced to improve its insulation performance. Second, rock wool boards are mainly produced by pendulum pressing, and there are many cavities between the internal fibers, which are basically unable to resist water erosion. Once they get wet, their insulation performance and structural stability will decrease. In addition, rock wool also has problems such as poor dimensional stability and low tensile strength, making it susceptible to structural damage from various factors in practical applications. Summary of the Invention

[0004] The primary objective of this 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 objective of this invention is to provide a method for preparing the above-mentioned high-strength thermal insulation rock wool board.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A high-strength thermal insulation rock wool board, wherein the high-strength thermal insulation rock wool board is composed of the following raw materials in parts by weight: 65-72 parts basalt, 10-15 parts dolomite, 8-12 parts iron ore, 3-8 parts bauxite, 2-5 parts limestone, 10-15 parts aerogel powder, and 4-7 parts binder.

[0008] The aerogel powder is prepared by the following process:

[0009] (1) Mix tetraethyl orthosilicate, ethanol and water, adjust the pH to 2.5-4, and stir under heating conditions to obtain silica sol;

[0010] (2) Disperse black phosphorus in water to obtain black phosphorus dispersion; mix black phosphorus dispersion with silica sol to form a mixture; adjust the pH of the mixture to 8-10; allow it to stand for aging; freeze dry; grind to obtain aerogel powder.

[0011] Further, in step (1), the volume ratio of tetraethyl orthosilicate, ethanol and water is 1:(3-5):(1-2), the heating temperature is 50-70℃, and the stirring time is 1-3h.

[0012] Further, in step (2), the ratio of black phosphorus to water is 1 g: 80-120 mL; the volume ratio of the black phosphorus dispersion to the silica sol is 1: 3.5-6.

[0013] Furthermore, the adhesive is prepared by the following process:

[0014] Silicon dioxide, aluminum oxide, titanium dioxide, zinc oxide, and gadolinium oxide are mixed evenly, heated to melt, quenched, and pulverized to obtain glass powder; the glass powder is then nitrided to obtain nitrided glass powder; sodium silicate is added to water and stirred to dissolve, then the nitrided glass powder is added, and the mixture is ultrasonicated, allowed to stand, and defoamed to obtain the binder.

[0015] Further, 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); and the heating and melting temperature is 1100-1300℃.

[0016] Furthermore, the nitriding treatment is performed by introducing ammonia gas into the glass powder for nitriding; the ammonia gas flow rate is 100-150 mL / min; the nitriding treatment temperature is 700-1000℃, and the time is 3-6 h.

[0017] Furthermore, the stirring and dissolving temperature is 40-50℃; the mass ratio of sodium silicate to glass nitride powder is 1:0.05-0.1.

[0018] The preparation method of the above-mentioned high-strength thermal insulation rock wool board includes the following steps:

[0019] (a) Basalt, dolomite, iron ore, bauxite and limestone are mixed evenly according to the stated weight proportions, heated to melt, centrifuged and stretched to obtain rock wool fibers;

[0020] (b) The rock wool fibers are settled by negative pressure suction to form a primary cotton strip. Adhesive and aerogel powder are sprayed onto the primary cotton strip, and then it is sent into a pendulum machine for folding to obtain a primary rock wool layer. The primary rock wool layer is pre-pressed and heated to solidify to obtain the rock wool board.

[0021] Further, the heating and melting temperature in step (a) is 1450-1550℃; the pre-pressing pressure in step (b) is 0.2-0.3MPa; and the heating and curing temperature is 200-300℃, and the time is 20-25min.

[0022] The beneficial technical effects of this invention are as follows:

[0023] 1. This invention adds black phosphorus-silica composite aerogel to rock wool boards, which can simultaneously improve the mechanical and thermal insulation properties of the rock wool boards and enhance their hydrophobicity. Silica aerogel has a special nano-network structure with advantages such as low density, large specific surface area, stable chemical properties, low thermal conductivity, and strong hydrophobicity. Adding it to rock wool boards can improve their durability and thermal insulation. During the pendulum-type fiber placement process, this invention uniformly sprays aerogel powder onto the fiber surface. Under the action of a binder, the aerogel powder adheres tightly to the surface of the rock wool fibers and the pores formed by fiber intersections, forming a uniform composite. Black phosphorus in the aerogel powder, as a nano-reinforcing phase, can disperse stress, hinder crack propagation, improve the strength of the aerogel, and thus improve the mechanical properties of the rock wool board.

[0024] 2. This invention adds nitrided glass powder to sodium silicate as a binder. The glass powder possesses high-temperature stability, and its addition to the binder enhances the thermal stability of sodium silicate, thereby improving the fire resistance of the rock wool board. Simultaneously, it also increases the strength of the rock wool board and improves the structural stability of the material. Surface nitriding treatment of the glass powder forms more dense Si3N4, AlN, TiN, and other phases on its surface, increasing the surface contact angle between the glass powder and water, reducing surface defects, lowering its surface energy, shortening the water molecule penetration path, reducing water adsorption capacity, enhancing the hydrophobicity of the binder, and improving the durability of the rock wool board. Attached Figure Description

[0025] Figure 1 This is a scanning electron microscope image of the aerogel powder prepared in Example 1 of the present invention;

[0026] Figure 2 This is a scanning electron microscope image of the adhesive obtained in Example 1 of the present invention after curing. Detailed Implementation

[0027] The following is a further detailed description of the present invention in conjunction with specific preferred embodiments, and it should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention. Specific conditions not specified in the embodiments are performed according to conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, all reagents or instruments used are conventional products obtained through commercial channels.

[0028] (I) Implementation Examples

[0029] Example 1

[0030] 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 basalt, 12 parts dolomite, 10 parts iron ore, 5 parts bauxite, 3 parts limestone, 12 parts aerogel powder, and 5 parts binder.

[0031] The aerogel powder is prepared by the following process:

[0032] (1) Tetraethyl orthosilicate, ethanol and water were mixed evenly in a volume ratio of 1:4:2. The pH was adjusted to 3 using 0.2 mol / L nitric acid. The mixture was then stirred at 60°C for 2 h to obtain silica sol.

[0033] (2) Black phosphorus was added to deionized water at a ratio of 1 g: 100 mL and ultrasonically dispersed in an ice-water bath for 30 min to obtain a black phosphorus dispersion. The black phosphorus dispersion was mixed with the above silica sol at a volume ratio of 1:5, and then 25% ammonia was added to adjust the pH to 9. After standing for 30 h, the mixture was freeze-dried and ground to obtain aerogel powder. The scanning electron microscope image of the aerogel powder is shown below. Figure 1 As shown.

[0034] The above-mentioned adhesive is prepared by the following process:

[0035] Silica, aluminum oxide, titanium dioxide, zinc oxide, and gadolinium oxide were mixed evenly in a mass ratio of 1:0.6:0.3:0.2:0.2, heated to 1200℃ to melt, quenched, and then pulverized to obtain glass powder. The glass powder was placed in a nitriding furnace, and ammonia gas was introduced at a flow rate of 120 mL / min. The mixture was reacted at 800℃ for 5 hours to obtain nitrided glass powder. Sodium silicate, nitrided glass powder, and deionized water were mixed in a mass ratio of 1:0.08:1.7. Sodium silicate was first added to deionized water and heated and stirred at 40℃ until dissolved. Then, nitrided glass powder was added and ultrasonically dispersed. After standing to defoam, an adhesive was obtained. The scanning electron microscope image of the cured adhesive is shown below. Figure 2 As shown.

[0036] This embodiment also provides a method for preparing the above-mentioned high-strength thermal insulation rock wool board, the specific operation steps of which are as follows:

[0037] (a) Basalt, dolomite, iron ore, bauxite and limestone are mixed evenly according to the above weight proportions, melted at 1500℃, centrifuged and stretched at 5000rpm to obtain rock wool fibers with a diameter of 4-9μm.

[0038] (b) Rock wool fibers are deposited on a conveyor belt by negative pressure suction. Adhesive and aerogel powder are sprayed on the rock wool fibers. The primary rock wool layer is obtained by folding the primary rock wool layer layer by layer by folding it back and forth on the conveyor belt using a pendulum method with a pendulum frequency of 110 times / min. The primary rock wool layer is pre-compressed by applying a pressure of 0.2MPa and then cured at 250℃ for 20min to obtain a rock wool board.

[0039] Example 2

[0040] 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 basalt, 10 parts dolomite, 8 parts iron ore, 3 parts bauxite, 2 parts limestone, 10 parts aerogel powder, and 4 parts binder.

[0041] The aerogel powder is prepared by the following process:

[0042] (1) Tetraethyl orthosilicate, ethanol and water were mixed evenly in a volume ratio of 1:3:1. The pH was adjusted to 2.5 using 0.1 mol / L nitric acid. The mixture was then stirred at 50°C for 1 h to obtain silica sol.

[0043] (2) Black phosphorus was added to deionized water at a ratio of 1g:80mL and ultrasonically dispersed in an ice-water bath for 20min to obtain a black phosphorus dispersion. The black phosphorus dispersion and the above silica sol were stirred and mixed at a volume ratio of 1:3.5. Then, 25% ammonia was added to adjust the pH to 8. After standing for 20h, the mixture was freeze-dried and ground to obtain aerogel powder.

[0044] The above-mentioned adhesive is prepared by the following process:

[0045] Silica, aluminum oxide, titanium dioxide, zinc oxide, and gadolinium oxide were mixed evenly in a mass ratio of 1:0.5:0.2:0.2:0.1, heated and melted at 1100℃, quenched, and then pulverized to obtain glass powder. The glass powder was placed in a nitriding furnace, and ammonia gas was introduced at a flow rate of 100 mL / min. The mixture was reacted at 700℃ for 3 hours to obtain nitrided glass powder. Sodium silicate, nitrided glass powder, and deionized water were mixed in a mass ratio of 1:0.05:1.5. Sodium silicate was first added to deionized water and heated and stirred at 40℃ until dissolved. Then, nitrided glass powder was added and ultrasonically dispersed. After standing to defoam, an adhesive was obtained.

[0046] This embodiment also provides a method for preparing the above-mentioned high-strength thermal insulation rock wool board, the specific operation steps of which are as follows:

[0047] (a) Basalt, dolomite, iron ore, bauxite and limestone are mixed evenly according to the above weight proportions, melted at 1450°C, centrifuged and stretched at 4500 rpm to obtain rock wool fibers with a diameter of 4-9 μm.

[0048] (b) Rock wool fibers are deposited on a conveyor belt by negative pressure suction. Adhesive and aerogel powder are sprayed on the rock wool fibers. The primary rock wool layer is obtained by folding the primary rock wool layer layer by layer by folding it back and forth on the conveyor belt using a pendulum method with a pendulum frequency of 100 times / min. The primary rock wool layer is pre-compressed by applying a pressure of 0.2MPa and then cured at 200℃ for 20min to obtain a rock wool board.

[0049] Example 3

[0050] 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 basalt, 15 parts dolomite, 12 parts iron ore, 8 parts bauxite, 5 parts limestone, 15 parts aerogel powder, and 7 parts binder.

[0051] The aerogel powder is prepared by the following process:

[0052] (1) Tetraethyl orthosilicate, ethanol and water were mixed evenly in a volume ratio of 1:5:2. The pH was adjusted to 4 using 0.3 mol / L nitric acid. The mixture was then stirred at 70°C for 3 h to obtain silica sol.

[0053] (2) Black phosphorus was added to deionized water at a ratio of 1g:120mL and ultrasonically dispersed in an ice-water bath for 30min to obtain a black phosphorus dispersion. The black phosphorus dispersion was mixed with the above silica sol at a volume ratio of 1:6. Then, 28% ammonia was added to adjust the pH to 10. After standing for 40h, the mixture was freeze-dried and ground to obtain aerogel powder.

[0054] The above-mentioned adhesive is prepared by the following process:

[0055] Silica, aluminum oxide, titanium dioxide, zinc oxide, and gadolinium oxide were mixed evenly in a mass ratio of 1:0.8:0.4:0.3:0.2, heated and melted at 1300℃, quenched, and then pulverized to obtain glass powder. The glass powder was placed in a nitriding furnace, and ammonia gas was introduced at a flow rate of 150 mL / min. The mixture was reacted at 1000℃ for 6 hours to obtain nitrided glass powder. Sodium silicate, nitrided glass powder, and deionized water were mixed in a mass ratio of 1:0.1:1.8. Sodium silicate was first added to deionized water and heated and stirred at 50℃ until dissolved. Then, nitrided glass powder was added and ultrasonically dispersed. After standing to defoam, an adhesive was obtained.

[0056] This embodiment also provides a method for preparing the above-mentioned high-strength thermal insulation rock wool board, the specific operation steps of which are as follows:

[0057] (a) Basalt, dolomite, iron ore, bauxite and limestone are mixed evenly according to the above weight proportions, melted at 1550°C, centrifuged and stretched at 5500 rpm to obtain rock wool fibers with a diameter of 4-9 μm.

[0058] (b) Rock wool fibers are deposited on a conveyor belt by negative pressure suction. Adhesive and aerogel powder are sprayed on the rock wool fibers. The primary rock wool layer is obtained by folding the primary rock wool layer layer by layer by folding it back and forth on the conveyor belt using a pendulum method with a pendulum frequency of 120 times / min. The primary rock wool layer is pre-compressed by applying a pressure of 0.3MPa and then cured at 300℃ for 25min to obtain a rock wool board.

[0059] (ii) Comparative Example

[0060] Comparative Example 1

[0061] Comparative Example 1 is basically the same as Example 1, except that the black phosphorus dispersion in step (2) is omitted when preparing aerogel powder, while the other steps remain unchanged.

[0062] Comparative Example 2

[0063] Comparative Example 2 is basically the same as Example 1, except that: when preparing the binder, glass nitride powder is omitted, that is, sodium silicate is used as the binder.

[0064] Comparative Example 3

[0065] Comparative Example 3 is basically 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.

[0066] (III) Experimental Examples

[0067] 1. Mechanical strength test: The tensile strength and compressive strength of the rock wool boards in Examples 1-3 and Comparative Examples 1-3 were tested in accordance with the national standard GB / T 25975-2018 "Rock wool products for external thermal insulation of building exterior walls"; the test results are shown in Table 1.

[0068] 2. Water absorption test: According to GB / T 25975-2018 "Rock wool products for external thermal insulation of building exterior walls", the water absorption performance of the rock wool boards in Examples 1-3 and Comparative Examples 1-4 was tested; the test results are shown in Table 1.

[0069] 3. Thermal conductivity test: The thermal conductivity of the rock wool boards in Examples 1-3 and Comparative Examples 1-4 was tested according to the national standard GB / T 10294-2008 "Determination of steady-state thermal resistance and related properties of thermal insulation materials - protective hot plate method"; the test results are shown in Table 1.

[0070] Table 1 Test results of mechanical, water absorption, and thermal conductivity properties of rock wool boards

[0071]

[0072] As shown in 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 significantly reducing water absorption but also having a low thermal conductivity, which helps to improve the thermal insulation effect.

[0073] Compared to Example 1, Comparative Example 1 omits black phosphorus in step (2), Comparative Example 2 omits glass nitride powder, and Comparative Example 3 replaces glass nitride powder with glass powder. The mechanical properties, hydrophobicity, and thermal insulation of Comparative Examples 1-3 all decrease to a certain extent. The above results indicate that: (1) The addition of black phosphorus-silica composite aerogel to rock wool boards in this invention can simultaneously improve the mechanical properties and thermal insulation performance of rock wool boards, and enhance the hydrophobicity of rock wool boards. Silica aerogel has a special nano-network structure, and therefore has advantages such as low density, large specific surface area, stable chemical properties, low thermal conductivity, and strong hydrophobicity. Adding it to rock wool boards can improve the durability and thermal insulation of rock wool boards. In the pendulum-type cotton laying process, the aerogel powder is evenly sprayed on the fiber surface. Under the action of the binder, the aerogel powder adheres tightly to the surface of the rock wool fibers and the pores formed by the fiber intersections, forming a uniform composite. Black phosphorus in aerogel powder, as a nano-reinforcing phase, can disperse stress, hinder crack propagation, improve the strength of aerogel, and thus improve the mechanical properties of rock wool board. (2) In this invention, adding nitrided glass powder to sodium silicate as a binder can improve the strength and hydrophobicity of 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 rock wool board. At the same time, it can also improve the strength of rock wool board and improve the structural stability of the material. Surface nitriding of glass powder can form more compacted Si3N4, AlN, TiN and other phases on its surface, increase the surface contact angle between glass powder and water, reduce the surface defects of glass powder, 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 rock wool board.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. The basic principles and main features of the present invention have been described above with specific implementation schemes. Based on the present invention, some modifications or substitutions can be made, but these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate 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: basalt 65-72 parts, dolomite 10-15 parts, iron ore 8-12 parts, bauxite 3-8 parts, limestone 2-5 parts, aerogel powder 10-15 parts, and binder 4-7 parts; The aerogel powder is prepared by the following process: (1) mixing tetraethyl orthosilicate, ethanol and water, adjusting pH to 2.5-4, stirring under heating conditions to obtain a silica sol; (2) dispersing black phosphorene in water to obtain a black phosphorene dispersion liquid; mixing the black phosphorene dispersion liquid with the silica sol to form a mixed liquid, adjusting the pH of the mixed liquid to 8-10, standing for aging, freeze-drying, and grinding to obtain the aerogel powder; The binder is prepared by the following process: mixing silica, alumina, titanium dioxide, zinc oxide and gadolinium oxide uniformly, heating and melting, quenching, and crushing to obtain glass powder; nitrogenizing the glass powder to obtain nitrogenized glass powder; stirring and dissolving sodium silicate in water, then adding the nitrogenized glass powder, ultrasonic treatment, standing, and defoaming to obtain the binder; The mass ratio of the silica, alumina, 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 temperature of the heating and melting is 1100-1300℃; The nitrogenizing operation is: nitrogenizing the glass powder by introducing ammonia gas; the flow rate of the ammonia gas is 100-150 mL / min; the temperature of the nitrogenizing is 700-1000℃, and the time is 3-6h.

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

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

4. The high strength thermal insulating rock wool slab according to claim 1, characterized in that, The temperature of the stirring and dissolving is 40-50℃; the mass ratio of the sodium silicate and the nitrogenized glass powder is 1:0.05-0.

1.

5. The method of manufacturing high strength thermal insulation rock wool board according to any one of claims 1 to 4, characterized in that, The method comprises the following steps: (a) uniformly mixing basalt, dolomite, iron ore, bauxite and limestone according to the weight parts, heating and melting, centrifuging and drawing to obtain rock wool fibers; (b) forming a primary cotton belt by suctioning the rock wool fibers, spraying the binder and the aerogel powder on the primary cotton belt, and then feeding the primary cotton belt into a pendulum machine to fold to obtain a primary rock wool layer; and pre-pressing the primary rock wool layer, and heating and curing to obtain the rock wool board.

6. The method for preparing high-strength thermal insulation rock wool board according to claim 5, characterized in that, In step (a), the temperature of the heating and melting is 1450-1550℃; in step (b), the pressure of the pre-pressing is 0.2-0.3 MPa; and the temperature of the heating and curing is 200-300℃, and the time is 20-25 min.

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