Calcium silicate heat preservation board for livestock shed back wall heat preservation structure and preparation method thereof

Abstract

The application provides a calcium silicate heat preservation plate of a livestock shed rear wall heat preservation structure and a preparation method thereof, and belongs to the technical field of building energy-saving heat preservation and livestock facility engineering material. The application uses fly ash desiliconization liquid as a silicon source, calcium hydroxide as a calcium source, and is supplemented with functional additives such as manganese, cobalt, nickel ions and cellulose, and a modified calcium silicate intermediate is synthesized through hydrothermal reaction in a reaction kettle. Then, the phosphoric acid is used for secondary structure adjustment, and the heat preservation plate with a standardized size is formed. In order to improve the durability, the prepared plate is soaked in a methyltrisbutyl ketoximyl silanol solution for waterproof treatment. The prepared heat preservation plate has the advantages of low thermal conductivity, high strength, strong waterproofness and convenient assembly, and is especially suitable for replacing the traditional cotton quilt type and cutting plate type heat preservation modes in the livestock industry, and has good industrialization and engineering application prospects.

Description

Technical Field

[0001] This invention relates to the field of building energy-saving insulation and livestock facility engineering materials, and in particular to a calcium silicate insulation board for the rear wall insulation structure of livestock sheds and its preparation method. Background Technology

[0002] Animal husbandry is a vital basic industry in my country, and in cold regions, it relies particularly heavily on stable and efficient insulation facilities for livestock sheds. Currently, the widely used cotton quilt-style insulation has several significant drawbacks: it requires manual rolling and unrolling in the morning and evening, resulting in high labor intensity; electric heating equipment is needed for nighttime heating, posing fire hazards; and cotton quilts absorb moisture severely, leading to significant deterioration after prolonged use. While foam board or cut-board insulation offers some thermal resistance, it suffers from prominent thermal bridging issues at the seams, is prone to cracking due to moisture absorption, and involves cumbersome maintenance and replacement processes. With the increasing intensification and automation of animal husbandry, developing a structurally complete, moisture-resistant, fire-resistant, safe, and integrally installable insulation material has become an urgent need for the construction of green livestock facilities. Summary of the Invention

[0003] The purpose of this invention is to provide a calcium silicate insulation board for the rear wall insulation structure of livestock sheds and its preparation method, so as to solve the technical problems of existing livestock shed insulation materials such as easy moisture absorption and cracking, and low safety.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0005] This invention provides a method for preparing calcium silicate insulation board for the rear wall insulation structure of livestock sheds, comprising the following steps:

[0006] 1) Using fly ash desilication liquid as the silicon source and calcium hydroxide as the calcium source, with the addition of additives, the mixture is subjected to a hydrothermal reaction to obtain calcium silicate intermediate;

[0007] 2) The calcium silicate intermediate was sequentially filtered, washed and dried, and then modified in phosphoric acid solution to obtain modified calcium silicate.

[0008] 3) The modified calcium silicate is pressed into boards and dried at 70~90℃. The dried boards are then soaked in a waterproof solution for treatment and dried at 50~70℃ to form a waterproof layer on the surface of the boards, thus obtaining the calcium silicate insulation board.

[0009] Furthermore, the Ca / Si molar ratio of the calcium source and silicon source is 1~1.2, and the SiO2 concentration in the fly ash desilication liquid is 60~70 g / L.

[0010] Furthermore, the additive comprises a metal ion additive and cellulose, wherein the metal ion additive comprises Mn 2+ Co 2+ and Ni 2+One or more of the above, wherein the amount of the metal ion additive is 3-6% of the total dry matter of the silicon source and calcium source, and the amount of cellulose added is 1-3% of the total dry matter of the silicon source and calcium source.

[0011] Furthermore, the hydrothermal reaction temperature is 200~250℃, and the hydrothermal reaction time is 10~14h.

[0012] Furthermore, the volume concentration of the phosphoric acid solution is 50-65%, the modification treatment is carried out at 40-60°C, and the solid-liquid ratio of the calcium silicate intermediate to the phosphoric acid solution is 1:4-6.

[0013] Furthermore, the waterproofing agent in the waterproofing solution comprises one or more of methyltributanone oxime silane, methyl silicone oil, isobutyltriethoxysilane, octyltriethoxysilane, and methyltrimethoxysilane;

[0014] The mass concentration of the waterproof solution is 1-3%, and the soaking time is 1-5 hours.

[0015] This invention provides a calcium silicate insulation board for the rear wall insulation structure of livestock sheds, wherein the thermal conductivity of the calcium silicate insulation board for the rear wall insulation structure of livestock sheds is less than 0.05 W·m. -1 ·K -1 It has a density of less than 0.7 g / cm³, a compressive strength of more than 8 MPa, a water absorption rate of less than 3%, and a freeze-thaw cycle resistance of not less than 30 times.

[0016] The beneficial effects of the present invention: The calcium silicate insulation board for the rear wall insulation structure of livestock sheds proposed in this invention uses fly ash, a bulk industrial solid waste, as raw material. The silicon source is widely available and waste utilization is realized. After the synthesized calcium silicate material is modified by metal ion additives and treated with phosphoric acid, its pore structure is rearranged and the pore structure is not easy to collapse, resulting in a lower thermal conductivity. At the same time, the surface soaking treatment eliminates the defect of easy water absorption. The prepared insulation board has the advantages of good heat insulation performance, low density, high strength, low water absorption rate, and good freeze-thaw resistance.

[0017] Testing revealed that the insulation board material produced by this invention has the following performance advantages: a thermal conductivity of 0.046 W·m. -1 ·K -1 It has a compressive strength of ≥8MPa, a water absorption rate of <3%, and can withstand ≥30 freeze-thaw cycles, fully meeting the performance requirements of the rear wall insulation structure of livestock sheds for thermal resistance, structural integrity, and environmental tolerance. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the "Z-shaped snap-fit ​​structure" of the calcium silicate insulation board of the present invention.

[0019] Figure 2 This is an enlarged view of the "Z-shaped snap-fit ​​structure";

[0020] Figure 3 This is a schematic diagram of the mosaic-style "convex and concave snap-fit ​​structure" of the calcium silicate insulation board of the present invention;

[0021] Figure 4 This is an enlarged view of the "convex and concave snap-fit ​​structure";

[0022] Figure 5 This is a schematic diagram of the puzzle-style "trapezoidal snap-fit ​​structure" of the calcium silicate insulation board of the present invention;

[0023] Figure 6 This is an enlarged view of the "trapezoidal snap-fit ​​structure";

[0024] Figure 7 The image shows the SEM image of the calcium silicate insulation board prepared in Example 1 of this invention.

[0025] Figure 8 This is a diagram showing the specific surface area and pore size analysis of the calcium silicate insulation board prepared in Example 1 of the present invention. Detailed Implementation

[0026] This invention provides a method for preparing calcium silicate insulation board for the rear wall insulation structure of livestock sheds, comprising the following steps:

[0027] 1) Using fly ash desilication liquid as the silicon source and calcium hydroxide as the calcium source, with the addition of additives, the mixture is subjected to a hydrothermal reaction to obtain calcium silicate intermediate;

[0028] 2) The calcium silicate intermediate was sequentially filtered, washed and dried, and then modified in phosphoric acid solution to obtain modified calcium silicate.

[0029] 3) The modified calcium silicate is pressed into boards and dried at 70~90℃. The dried boards are then soaked in a waterproof solution for treatment and dried at 50~70℃ to form a waterproof layer on the surface of the boards, thus obtaining the calcium silicate insulation board.

[0030] In this invention, the Ca / Si molar ratio of the calcium source and the silicon source is 1 to 1.2, preferably 1; the concentration of SiO2 in the fly ash desilication liquid is 60 to 70 g / L, preferably 60 to 68 g / L, and more preferably 62 to 65 g / L.

[0031] In this invention, the additive comprises a metal ion additive and cellulose, wherein the metal ion additive comprises Mn. 2+ Co 2+ and Ni 2+One or more of the above, wherein the amount of the metal ion additive is 3-6% of the total dry weight of the silicon source and calcium source, preferably 3.5-4.5%, and more preferably 4%; and the amount of cellulose added is 1-3% of the total dry weight of the silicon source and calcium source, preferably 1.5-2.5%, and more preferably 2%.

[0032] In this invention, the temperature of the hydrothermal reaction is 200~250℃, preferably 210~240℃, and more preferably 220~230℃; the time of the hydrothermal reaction is 10~14h, preferably 12h.

[0033] In this invention, the volume concentration of the phosphoric acid solution is 50-65%, preferably 60%; the modification treatment is carried out at 40-60°C, preferably 50°C; the solid-liquid ratio of the calcium silicate intermediate to the phosphoric acid solution is 1:4-6, preferably 1:5.

[0034] In this invention, the waterproofing agent in the waterproofing solution comprises one or more of methyltributanone oxime silane, methyl silicone oil, isobutyltriethoxysilane, octyltriethoxysilane and methyltrimethoxysilane, preferably methyltributanone oxime silane.

[0035] The mass concentration of the waterproof solution is 1-3%, preferably 1.5-2%; the soaking time is 1-5 hours, preferably 2-3 hours.

[0036] This invention provides a calcium silicate insulation board for the rear wall insulation structure of livestock sheds, wherein the thermal conductivity of the calcium silicate insulation board for the rear wall insulation structure of livestock sheds is less than 0.05 W·m. -1 ·K -1 It has a density of less than 0.7 g / cm³, a compressive strength of more than 8 MPa, a water absorption rate of less than 3%, and a freeze-thaw cycle resistance of not less than 30 times.

[0037] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0038] Example 1

[0039] 1) Fly ash desilication liquid (SiO2 concentration approximately 60 g / L) was selected as the silicon source, supplemented with calcium hydroxide, and the Ca / Si molar ratio was adjusted to 1. Mn was added simultaneously. 2+ (Manganese sulfate), Co 2+ (Cobalt sulfate), Ni 2+Nickel sulfate and other multi-metal ion regulators were added, with a total addition amount of 4.5% of the dry matter; 1.5% hydroxypropyl methylcellulose (HPMC) was added to enhance the dispersibility and toughness of the material. After thorough mixing, the mixture was poured into a 50 L reactor and hydrothermally reacted at 220℃ and a stirring rate of 200 r / min for 12 hours. After cooling, filtration, and drying, calcium silicate intermediate was obtained.

[0040] 2) Add the calcium silicate intermediate to a 60% dilute phosphoric acid aqueous solution (solid-liquid ratio 1:5) and react at 50 °C for 2 hours. The phosphoric acid introduces the structural hydroxyapatite component, improving the thermal resistance and density of the material. Wash and dry before use.

[0041] 3) Thoroughly mix the powder with deionized water at a liquid-to-solid ratio of 0.3:1, and press it into standard-sized boards of 1 m × 1.2 m × 2 cm. Design a "tenon-groove" structure on the edges of the boards, allowing adjacent boards to be securely connected via a snap-fit ​​mechanism, eliminating the need for additional adhesives on-site. After pressing, dry at 80 ℃ for 24 hours to solidify.

[0042] 4) The formed plate is soaked in a 1.5% methyl tributanone oxime silane ethanol solution for 2 hours and then dried at 60°C for 12 hours to form a dense hydrophobic coating.

[0043] Test results show that the thermal conductivity of the insulation board obtained in Example 1 is 0.046 W·m. -1 ·K -1 It has a water absorption rate of 2.1% and shows no cracks after 30 freeze-thaw cycles.

[0044] Example 2

[0045] The fly ash desilication liquid was adjusted to a Si concentration of 70 g / L, the Ca / Si ratio was adjusted to 1.2 with calcium hydroxide, and the metal ion ratio was increased to 6%, with the rest remaining the same as in Example 1. The thermal conductivity of the finished insulation board was 0.043 W·m. -1 ·K -1 It has a compressive strength of 9.3 MPa and a water absorption rate of 2.5%.

[0046] Example 3

[0047] The following were used: 8 L of industrial desilication solution, 0.6 kg of calcium hydroxide, and Mn as an additive. 2+ Ni 2+ Each component accounts for 2%, without cobalt salt, and HPMC is 1%. Other reaction conditions are the same as in Example 1. After waterproofing treatment, the board maintains good hydrophobicity in a high-humidity environment at 40 °C. After boiling in water, no peeling or structural delamination was observed on the surface, verifying its durability under extreme environments.

[0048] Example 4

[0049] Using fly ash desilication liquid (SiO2 concentration of 65 g / L) as the silicon source and calcium hydroxide as the calcium source, the Ca / Si molar ratio was controlled at 1.1, and Mn was used as the additive. 2+ Ni 2+ Co 2+ Each component accounts for 1%, with HPMC at 2%. The waterproofing solution used is a 2% alcohol solution of methyl silicone oil; other reaction conditions are the same as in Example 1. The thermal conductivity of the finished insulation board is 0.044 W·m. -1 ·K -1 It has a compressive strength of 8.5 MPa and a water absorption rate of 2.6%.

[0050] Example 5

[0051] Using fly ash desilication liquid (SiO2 concentration of 68 g / L) as the silicon source and calcium hydroxide as the calcium source, the Ca / Si molar ratio was controlled at 1.0, and 2% Mn was added as an additive. 2+ 1% Ni 2+ 1% Co 2+ The HPMC content was 1.5%. The waterproofing solution used was a 1.5% isobutyltriethoxysilane alcohol solution, and other reaction conditions were the same as in Example 1. The thermal conductivity of the finished insulation board was 0.046 W·m. -1 ·K -1 It has a compressive strength of 8.0 MPa and a water absorption rate of 2.3%.

[0052] Example 6

[0053] Using fly ash desilication liquid (SiO2 concentration of 62 g / L) as the silicon source and calcium hydroxide as the calcium source, the Ca / Si molar ratio was controlled at 1.2, and Ni was used as the additive. 2+ Co 2+ Each component accounts for 2%, with HPMC accounting for 2%. The waterproofing solution used is a 2.5% alcohol solution of octyltriethoxysilane, and other reaction conditions are the same as in Example 1. The thermal conductivity of the finished insulation board is 0.050 W·m. -1 ·K -1 It has a compressive strength of 9.0 MPa and a water absorption rate of 2.8%.

[0054] Example 7

[0055] Using fly ash desilication liquid (SiO2 concentration of 63 g / L) as the silicon source and calcium hydroxide as the calcium source, the Ca / Si molar ratio was controlled at 1.0, and Mn was used as the additive. 2+ Co 2+ Each component accounts for 2%, with HPMC accounting for 3%. The waterproofing solution used is a 3% alcohol solution of methyltrimethoxysilane, and other reaction conditions are the same as in Example 1. The thermal conductivity of the finished insulation board is 0.047 W·m. -1 ·K -1It has a compressive strength of 9.5 MPa and a water absorption rate of 2.6%.

[0056] Depend on Figure 7 It can be seen that the insulation board has a porous and fluffy fibrous structure, which can achieve low thermal conductivity.

[0057] Figure 8 As shown, the calcium silicate insulation board prepared in Example 1 has a large specific surface area, reaching 382.02 m². 2 The high specific surface area ( / g) leads to a decrease in thermal conductivity; and the presence of a mesoporous structure around 4nm is also a reason for the low thermal conductivity.

[0058] Comparative Example 1

[0059] Same as Example 1, except that 1.5% hydroxypropyl methylcellulose (HPMC) is not added.

[0060] Test results show that the thermal conductivity of the insulation board obtained in Comparative Example 1 is 0.058 W·m. -1 ·K -1 The water absorption rate is 8.5%, and surface cracks appear after 20 freeze-thaw cycles (the lack of cellulose leads to poor material dispersibility, loose structure, and decreased strength and water resistance).

[0061] Comparative Example 2

[0062] Same as Example 1, except that the fly ash desilication liquid was adjusted to a Si concentration of 70 g / L, and the Ca / Si ratio was adjusted to 1.5 with calcium hydroxide.

[0063] Test results show that the thermal conductivity of the insulation board obtained in Comparative Example 2 is 0.062 W·m. -1 ·K -1 The water absorption rate is 6.2%, and the edges peel off after 18 freeze-thaw cycles (the excessively high Ca / Si ratio destroys the calcium silicate crystal structure, reducing porosity but increasing brittleness).

[0064] Comparative Example 3

[0065] Same as Example 1, except that no metal ion regulator is added.

[0066] Test results show that the thermal conductivity of the insulation board obtained in Comparative Example 3 is 0.085 W·m. -1 ·K -1 The water absorption rate is 9.8%, and it severely powders after 15 freeze-thaw cycles (due to lack of metal ion cross-linking, pore collapse leading to increased thermal conductivity and deterioration of structural stability).

[0067] Comparative Example 4

[0068] Similar to Example 1, except that the calcium silicate intermediate is not phosphorylated, but directly dried and mixed with deionized water to form a board.

[0069] Test results show that the thermal conductivity of the insulation board obtained in Comparative Example 4 is 0.071 W·m. -1 ·K -1 The water absorption rate is 13.5%. After 12 freeze-thaw cycles, it delaminates and breaks (no calcium hydroxyphosphate reinforcing phase is formed, the material has poor density and strong hydrophilicity).

[0070] Comparative Example 5

[0071] Same as Example 1, except that the board is not waterproofed.

[0072] Test results show that the thermal conductivity of the insulation board obtained in Comparative Example 4 is 0.049 W·m. -1 ·K -1 It has a water absorption rate of 28.3% and completely disintegrates after 8 freeze-thaw cycles (there is no hydrophobic layer on the surface, and water quickly penetrates and destroys the microstructure).

[0073] As can be seen from the above embodiments, the present invention provides a calcium silicate insulation board for the rear wall insulation structure of livestock sheds and its preparation method. To enhance construction convenience and the sealing of the connections between the boards, the edges of the insulation board are designed with a "convex-concave interlocking groove structure" to achieve splicing... Figure 1 Such precise splicing and installation. The insulation boards produced have advantages such as low thermal conductivity, high strength, strong waterproofness, and convenient assembly. They are particularly suitable for replacing traditional cotton quilt-style and cut-board-style insulation methods in livestock buildings, and have good prospects for industrialization and engineering applications.

[0074] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a calcium silicate insulation board for the rear wall insulation structure of a livestock shed, characterized in that, Includes the following steps: 1) Using fly ash desilication liquid as the silicon source and calcium hydroxide as the calcium source, with the addition of additives, the mixture is subjected to a hydrothermal reaction to obtain calcium silicate intermediate; 2) The calcium silicate intermediate was sequentially filtered, washed and dried, and then modified in phosphoric acid solution to obtain modified calcium silicate. 3) The modified calcium silicate is pressed into boards and dried at 70~90℃. The dried boards are then soaked in a waterproof solution for treatment. After drying at 50~70℃, a waterproof layer is formed on the surface of the boards, thus obtaining the calcium silicate insulation board. The additive comprises a metal ion additive and cellulose, the metal ion additive comprising Mn 2+ Co 2+ and Ni 2+ One or more of the above, wherein the amount of the metal ion additive is 3-6% of the total dry weight of the silicon source and calcium source, and the amount of cellulose added is 1-3% of the total dry weight of the silicon source and calcium source; The waterproofing agent in the waterproofing solution contains one or more of methyltributanone oxime silane, methyl silicone oil, isobutyltriethoxysilane, octyltriethoxysilane, and methyltrimethoxysilane; The mass concentration of the waterproof solution is 1-3%, and the soaking time is 1-5 hours.

2. The method for preparing the calcium silicate insulation board for the rear wall insulation structure of livestock sheds according to claim 1, characterized in that, The Ca / Si molar ratio of the calcium source and silicon source is 1~1.2, and the SiO2 concentration in the fly ash desilication liquid is 60~70g / L.

3. The method for preparing the calcium silicate insulation board for the rear wall insulation structure of livestock sheds according to claim 2, characterized in that, The hydrothermal reaction temperature is 200~250℃, and the hydrothermal reaction time is 10~14h.

4. The method for preparing the calcium silicate insulation board for the rear wall insulation structure of livestock sheds according to claim 1, 2, or 3, characterized in that, The phosphoric acid solution has a volume concentration of 50-65%, the modification treatment is carried out at 40-60°C, and the solid-liquid ratio of the calcium silicate intermediate to the phosphoric acid solution is 1:4-6.

5. The calcium silicate insulation board for the rear wall insulation structure of livestock sheds prepared by the preparation method according to any one of claims 1 to 4, characterized in that, The thermal conductivity of the calcium silicate insulation board in the rear wall insulation structure of the livestock shed is less than 0.05 W·m. -1 ·K -1 It has a density of less than 0.7 g / cm³, a compressive strength of more than 8 MPa, a water absorption rate of less than 3%, and a freeze-thaw cycle resistance of not less than 30 times.

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