Calcium silicate board with purifying, humidifying and antibacterial properties and preparation method thereof

Abstract

The invention belongs to the technical field of silicate boards, and particularly discloses a calcium silicate board with purifying, humidifying and antibacterial properties and a preparation method of the calcium silicate board. The preparation method comprises the following steps: firstly, mixing slaked lime powder, building gypsum, quartz powder, diatomite, bleached softwood log fibers, basalt fibers, expanded perlite and titanium-containing composite slurry with water, and carrying out slurry flowing to form a thin material layer; then atomizing and spraying the zinc-containing composite slurry on the surface of the thin material layer to obtain a modified thin material layer; the modified thin material layers and the thin material layers are stacked and then sequentially subjected to pre-curing, autoclaved curing treatment and polishing treatment, and the calcium silicate board with the purifying, humidifying and antibacterial properties is obtained. Compared with a traditional plate, the prepared calcium silicate plate has better breaking strength and excellent purifying, humidifying and antibacterial performance, and the plate is A1-level non-combustible, environment-friendly and healthy. And the surface pattern effect is extremely decorative, so that the LED lamp can be directly mounted and used, and additional surface treatment is not needed.

Description

Technical Field

[0001] The present invention relates to the technical field of silicate boards, and in particular to a calcium silicate board with purification, humidity-regulating and antibacterial properties and a preparation method thereof. Background Art

[0002] Calcium silicate board is made from siliceous and calcium-based materials as the primary binder, reinforced with inorganic mineral fibers or cellulose fibers, and then formed, pressed (or not), and autoclaved for curing. Calcium silicate board is typically used for indoor partitions and ceilings, and typically requires surface treatment such as coating to enhance decorative or other functional effects. However, with the growing demand for green buildings and healthy living environments, the limited functionality of traditional calcium silicate board is increasingly becoming a constraint on its further development.

[0003] Since people spend most of their time indoors, the decorative materials used in indoor spaces are particularly important to the human body. Various functional boards are available on the market, but their functionality is relatively limited, requiring multiple combinations or combinations to achieve multiple health benefits. In particular, there are few reports on the functional properties of calcium silicate boards. Conventional calcium silicate boards are unable to effectively absorb or catalytically decompose harmful gases such as formaldehyde and benzene released by interior decoration materials, making them unable to meet the stringent indoor air quality requirements of modern buildings. Furthermore, traditional boards have limited humidity control properties. They cannot effectively absorb moisture in high-humidity environments to prevent condensation and mold, nor can they release moisture to maintain a comfortable humidity level in dry environments, limiting their applicability in regions with variable climates. Furthermore, conventional calcium silicate boards are susceptible to mold and bacteria growth in long-term humid environments, which not only affects their aesthetics but can also cause respiratory diseases and allergic reactions. Existing modification methods, such as adding antimicrobial agents such as silver ions, often suffer from high costs and poor durability. Although studies in recent years have attempted to give calcium silicate boards purification and humidity control functions by loading photocatalysts or composite porous materials, these methods generally have defects such as complex preparation process, uneven dispersion of functional components, and insufficient long-term stability. In addition, most modification schemes will significantly reduce the mechanical properties of the material or greatly increase production costs, which restricts their industrial application.

[0004] Therefore, how to provide a calcium silicate board with purification, humidity control and antibacterial properties and a preparation method thereof, improve the functionality of the calcium silicate board, and enable it to have purification, humidity control and antibacterial properties is a difficult problem that needs to be solved urgently in this field. Summary of the Invention

[0005] In view of this, the present invention provides a calcium silicate board with purification, humidity control and antibacterial properties and a preparation method thereof to solve the problem of single function of existing calcium silicate boards. In addition, the present invention also improves the appearance effect of the calcium silicate board, which can be directly installed and used without further surface treatment such as coating.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for preparing a calcium silicate board with purification, humidity control and antibacterial properties comprises the following steps:

[0008] 1) mixing slaked lime powder, building gypsum, quartz powder, diatomaceous earth, bleached coniferous wood fiber, basalt fiber, expanded perlite and titanium-containing composite slurry with water to obtain a mixed slurry, and flowing the mixed slurry to form a thin material layer;

[0009] 2) spraying the zinc-containing composite slurry onto the surface of the thin material layer to obtain a modified thin material layer;

[0010] 3) After stacking the modified thin material layer and the thin material layer, pre-curing, autoclaving curing and polishing are sequentially performed to obtain a calcium silicate board with purification, humidity control and antibacterial properties.

[0011] Preferably, the mass ratio of the slaked lime powder, building gypsum, quartz powder, diatomaceous earth, bleached coniferous wood fiber, basalt fiber, expanded perlite, titanium-containing composite pulp and zinc-containing composite pulp is 24-30:5-8:30-40:12-20:3-8:2-5:1-2:4-6:2-4 on a dry weight basis.

[0012] Preferably, the solid content of the mixed slurry in step 1) is 13-16%;

[0013] The thickness of the thin material layer is 0.8-1 mm.

[0014] Preferably, the bleached coniferous wood fiber in step 1) is obtained by beating bleached coniferous wood pulp;

[0015] The beating degree of the pulping is 25-30°SR.

[0016] Preferably, the preparation method of the titanium-containing composite slurry in step 1) is:

[0017] Mixing titanium dioxide, aluminum hydroxide, bentonite and water to obtain titanium-containing composite slurry;

[0018] The solid content of the titanium-containing composite slurry is 10-20%;

[0019] The mass ratio of titanium dioxide, aluminum hydroxide and bentonite is 30-50:30-50:10-30;

[0020] The particle size of the titanium dioxide is 100 to 500 nm; the particle sizes of the aluminum hydroxide and bentonite are independently 500 to 1000 nm.

[0021] Preferably, the preparation method of the zinc-containing composite slurry in step 2) is:

[0022] Mixing zinc oxide, silica fume and water to obtain zinc-containing composite slurry;

[0023] The solid content of the zinc-containing composite slurry is 3 to 8%;

[0024] The mass ratio of zinc oxide to silica fume is 20-40:60-80;

[0025] The particle size of the zinc oxide is 10-100 nm, and the particle size of the silica fume is 100-500 nm.

[0026] Preferably, the stacking in step 3) comprises stacking multiple modified thin material layers with multiple thin material layers;

[0027] The thickness of the stacked slabs is 5 to 15 mm.

[0028] Preferably, the stacked slab contains three modified thin material layers.

[0029] Preferably, the pre-curing temperature in step 3) is 60-90° C., the humidity is ≥95%, and the time is 6-10 hours;

[0030] In step 3), the pressure of autoclaving is 0.8-1.2 MPa, the time is 5-10 hours, and the temperature is 160-200°C.

[0031] Another object of the present invention is to provide a calcium silicate board having purification, humidity-regulating and antibacterial properties prepared by the above preparation method.

[0032] It can be seen from the above technical solutions that compared with the prior art, the present invention has the following beneficial effects:

[0033] 1) The calcium silicate board with purification, humidity control and antibacterial properties prepared by the present invention has better flexural strength than traditional fiber-reinforced calcium silicate boards at the same density, and is a lightweight and high-strength board.

[0034] 2) The calcium silicate board with purification, humidity-regulating and antibacterial properties prepared by the present invention has excellent purification, humidity-regulating and antibacterial properties.

[0035] 3) The calcium silicate board with purification, humidity control and antibacterial properties prepared by the present invention is a completely inorganic board. The board is A1 grade non-combustible and has excellent indicators such as formaldehyde emission, heavy metal content, and total volatile organic compounds (TVOC). It is an environmentally friendly and healthy board.

[0036] 4) The product prepared by the present invention has a uniform color throughout and a polished surface. The overall color and surface pattern effects are highly decorative and can be directly installed and used without the need for surface treatment such as coating like ordinary calcium silicate boards.

[0037] 5) The product prepared by the present invention can be used in places with clear requirements for antibacterial properties, such as hospitals, schools, and shopping malls, and can also be used in home decoration and renovation places with higher requirements for environmental health. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0039] Figure 1 This is a comparison diagram of the calcium silicate board prepared in Example 1 of the present invention and the existing calcium silicate board, wherein: Figure 1 a in corresponds to Example 1, Figure 1 The b in the figure corresponds to the existing calcium silicate board. DETAILED DESCRIPTION

[0040] The present invention provides a method for preparing a calcium silicate board with purification, humidity control and antibacterial properties, comprising the following steps:

[0041] 1) mixing slaked lime powder, building gypsum, quartz powder, diatomaceous earth, bleached coniferous wood fiber, basalt fiber, expanded perlite and titanium-containing composite slurry with water to obtain a mixed slurry, and flowing the mixed slurry to form a thin material layer;

[0042] 2) spraying the zinc-containing composite slurry onto the surface of the thin material layer to obtain a modified thin material layer;

[0043] 3) After stacking the modified thin material layer and the thin material layer, pre-curing, autoclaving curing and polishing are sequentially performed to obtain a calcium silicate board with purification, humidity control and antibacterial properties.

[0044] In the present invention, the mass ratio of the slaked lime powder, building gypsum, quartz powder, diatomaceous earth, bleached coniferous wood fiber, basalt fiber, expanded perlite, titanium-containing composite slurry and zinc-containing composite slurry is 24-30:5-8:30-40:12-20:3-8:2-5:1-2:4-6:2-4 on a dry weight basis; under the above mass ratio, the mass ratio of the slaked lime powder can be specifically 25, 26, 27, 28, 29; the mass ratio of the building gypsum can be specifically 5.5, 6, 6.5, 7, 7.5; the mass ratio of the quartz powder can be specifically 32, 34, 35, 36, 38 ; The specific mass ratio values ​​of diatomaceous earth can be 14, 15, 16, and 18; the specific mass ratio values ​​of bleached coniferous log fiber can be 4, 5, 6, and 7; the specific mass ratio values ​​of basalt fiber can be 2.5, 3, 3.5, 4, and 4.5; the specific mass ratio values ​​of expanded perlite can be 1.2, 1.4, 1.5, 1.6, and 1.8; the specific mass ratio values ​​of titanium-containing composite pulp can be 4.2, 4.5, 4.8, 5, 5.2, 5.5, and 5.8; the specific mass ratio values ​​of zinc-containing composite pulp can be 2.2, 2.5, 2.8, 3, 3.2, 3.5, and 3.8.

[0045] In the present invention, the prepared product has a fine porous structure, which is provided by the synthetic reaction product, diatomaceous earth, and expanded perlite, and can maintain good moisture absorption and respiratory functions. The present invention uses a specific ratio of slaked lime powder and building gypsum as the main silicon-calcium material, which can be coordinated by the rapid hydration of gypsum and the slow carbonization of slaked lime to accelerate the early strength formation and improve the later durability. Diatomaceous earth and quartz powder are also used as the main silicon-calcium materials. The microporous structure of diatomaceous earth can improve the adsorption performance of the board (such as humidity control and air purification), while quartz powder increases the activity of the siliceous component, promotes the formation of tobermorite crystals during autoclaving, and enhances mechanical properties. The present invention also uses bleached coniferous wood fiber and basalt fiber as reinforcing materials. The bleached coniferous wood fiber has the characteristics of environmental protection, is human-friendly when used in building materials, and has low cost. Its flexibility can reduce the brittleness of the board; the fiber treated by the present invention can reduce the sensitivity of lignin to alkaline environment and improve durability. Basalt fiber has the characteristics of high temperature resistance and corrosion resistance, and can form a balance with bleached coniferous wood fiber.

[0046] In the present invention, the solid content of the mixed slurry in step 1) is 13-16%, specifically 13.5%, 14%, 14.5%, 15%, or 15.5%.

[0047] In the present invention, the thickness of the thin material layer is 0.8-1 mm, specifically 0.85 mm, 0.9 mm, or 0.95 mm.

[0048] In the present invention, the bleached coniferous wood fibers in step 1) are obtained by beating bleached coniferous wood pulp.

[0049] In the present invention, the mass concentration of the bleached coniferous wood fiber in the mixed liquor for beating is preferably 3%.

[0050] In the present invention, the beating degree of the pulp is 25-30°SR, specifically 26°SR, 27°SR, 28°SR, or 29°SR, and the wet weight is 9-12g, specifically 9.5g, 10g, 10.5g, 11g, or 11.5g (tested by a Schober beating degree meter).

[0051] In the present invention, the preparation method of the titanium-containing composite slurry in step 1) is:

[0052] Titanium dioxide, aluminum hydroxide, and bentonite are mixed with water to form a titanium-containing composite slurry. This method utilizes continuous stirring to fully utilize the micro-flocculation effect of titanium dioxide and aluminum hydroxide and the colloid-forming suspension effect of bentonite. The three materials form a simple composite that can be fully retained during the felt slurry dehydration and forming cylinder dehydration processes without being carried away by water, thus fully ensuring their effective content in the final product.

[0053] In the present invention, the solid content of the titanium-containing composite slurry is 10-20%, specifically 12%, 14%, 15%, 16%, or 18%.

[0054] In the present invention, the mass ratio of titanium dioxide, aluminum hydroxide and bentonite is 30-50:30-50:10-30, preferably 35-45:35-45:15-25, more preferably 38-42:38-42:18-22, and further preferably 40:40:20.

[0055] In the present invention, the particle size of the titanium dioxide is 100-500 nm, specifically 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, and 450 nm; the particle sizes of the aluminum hydroxide and bentonite are independently 500-1000 nm, specifically 600 nm, 700 nm, 800 nm, and 900 nm.

[0056] In the present invention, the preparation method of the zinc-containing composite slurry in step 2) is:

[0057] Zinc oxide, silica fume, and water are mixed to form a zinc-containing composite slurry. The zinc oxide and silica fume are fully emulsified and composited, making the silica fume a carrier for the zinc oxide. The slurry exhibits good composite uniformity and fluidity, making it easy to implement atomized spray addition. Furthermore, the relevant components can be fully retained during the forming and dehydration process of the forming cylinder and will not be carried away by water, fully ensuring their effective content in the final product.

[0058] In the present invention, during the thin layer stacking process, the first few layers (preferably the first three layers) are continuously and evenly sprayed with zinc-containing composite slurry (forming the modified thin layer) through an atomizing spray device, which can ensure the effective zinc component content on the product surface. At the same time, the silica fume in the composite slurry forms more solid crystals after hydration reaction, ensuring that the product surface is easy to process and polish.

[0059] In the present invention, the solid content of the zinc-containing composite slurry is 3-8%, more preferably 4%, 5%, 6%, or 7%.

[0060] In the present invention, the mass ratio of zinc oxide to silica fume is 20-40:60-80, preferably 25-35:65-75, more preferably 28-32:68-72, and further preferably 30:70.

[0061] In the present invention, the particle size of the zinc oxide is 10 to 100 nm, specifically 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, and 90 nm; the particle size of the silica ash is 100 to 500 nm, specifically 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, and 450 nm.

[0062] In the present invention, the stacking in step 3) includes stacking multiple modified thin material layers with multiple thin material layers; the stacking method is preferably multiple modified thin material layers / multiple thin material layers.

[0063] In the present invention, the thickness of the stacked slabs is 5 to 15 mm, specifically 6 mm, 8 mm, 10 mm, 12 mm, or 14 mm.

[0064] In the present invention, the stacked slab contains three modified thin material layers.

[0065] In the present invention, the pre-curing temperature in step 3) is 60-90°C, specifically 65°C, 70°C, 75°C, 80°C, 85°C; the humidity is ≥95%, specifically 95%, 96%, 97%, 98%, 99%; and the time is 6-10h, specifically 6h, 7h, 8h, 9h, 10h.

[0066] In the present invention, the pressure of autoclave curing in step 3) is 0.8-1.2 MPa, specifically 0.9 MPa, 1 MPa, or 1.1 MPa; the time is 5-10 h, specifically 6 h, 7 h, 8 h, 9 h, or 10 h; and the temperature is 160-200° C., specifically 165° C., 170° C., 175° C., 180° C., 185° C., 190° C., or 195° C.

[0067] The present invention uses an autoclave curing process. After sufficient hydration reaction, the product forms microporous calcium silicate crystals. The microporous effects of diatomaceous earth and perlite are combined to give the product a moisture absorption function. At the same time, titanium oxide powder and zinc oxide powder are complexed in the reaction product, and the product also has purification and antibacterial properties.

[0068] After the product is autoclaved and synthesized, it undergoes surface polishing treatment. Since the surface layer is sprayed with zinc-containing composite slurry when it is formed, the reaction product is uniform and dense. The polishing process can easily present the overall color and pattern effects while removing the surface reaction water marks, which has a very aesthetic effect. The polishing process only removes the surface reaction water marks and will not affect the actual components of the surface layer. The zinc-containing effective components of the surface layer can be completely retained and will not affect its performance.

[0069] The present invention also provides a calcium silicate board with purification, humidity-regulating and antibacterial properties prepared by the above preparation method.

[0070] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0071] The raw materials used in the embodiments of the present invention are all common commercially available materials. The specific requirements are as follows, which are not considered to limit the present invention:

[0072] Slaked lime powder: Ca(OH)2 content is more than 90%, 250 mesh sieve residue is less than 5%, whiteness is more than 85%.

[0073] Building gypsum: effective cementitious material content is more than 60%.

[0074] Quartz powder: SiO2 content above 95%, 250 mesh sieve residue below 5%, whiteness above 85%.

[0075] Diatomaceous earth: calcined diatomaceous earth, SiO2 content above 95%, 200 mesh sieve residue below 5%, whiteness above 85%.

[0076] Basalt fiber: fiber diameter 7-20 μm, density 2.6-2.8 g / cm3 .

[0077] Expanded perlite: closed-pore perlite, particle size 0.5mm~1mm.

[0078] Examples 1 to 4

[0079] Mix general bleached coniferous pulp with water to obtain a mixed pulp with a mass concentration of 3%, and beat it to prepare a pulp with a beating degree of 30°SR and a wet weight of 10g for later use; prepare composite powder according to the ratio of 40% of 200-300nm titanium dioxide, 40% of 600-800nm ​​aluminum hydroxide, and 20% of 600-800nm ​​bentonite, add water and hydraulically stir for 4 hours to prepare a titanium-containing composite pulp with a solid content of 15% for later use; prepare composite powder according to the ratio of 30% of 10-50nm zinc oxide and 70% of 100-200nm silica fume, add water and emulsify and stir for 0.5h to prepare a zinc-containing composite pulp with a solid content of 5% for later use; soak the expanded perlite with an appropriate amount of water for 4 hours and set aside.

[0080] After mixing all materials except the zinc-containing composite slurry in appropriate proportions, water is added and stirred until the solids content reaches 15%. The slurry is then flowed to form a 1.0mm thick thin layer. The layers are then stacked using a forming drum to form a 10mm thick slab. During the first three layers of the stacking process, the zinc-containing composite slurry is continuously and evenly sprayed in the formulated proportions using an atomizing spray device.

[0081] After the slabs are formed, they are stacked in a mold and placed in a pre-curing room for 8 hours at a temperature of 80°C and a humidity of 95%. After pre-curing, they are demolded and placed in an autoclave for curing. The autoclave curing schedule is as follows: 4 hours of increasing the pressure to 1.0 MPa, 8 hours of maintaining the pressure at 180°C, and 4 hours of reducing the pressure before exiting the autoclave. After exiting the autoclave, they are dried at 120°C to a moisture content of 8% by weight. The surface is then polished in a polishing machine to produce calcium silicate board with purifying, humidity-regulating, and antibacterial properties.

[0082] Table 1 Percentage of raw materials in Examples 1 to 4 (based on dry material mass)

[0083] Material Example 1 Example 2 Example 3 Example 4 Slaked lime powder 26 24 30 26 Building plaster 7 6 7 5 Quartz powder 35 40 33 32 diatomite 16 17 12 20 Bleached coniferous wood pulp 4.5 4 5 3 Basalt fiber 2 2 2 3 Expanded perlite 1.5 1 2 1 Titanium-containing composite slurry 5 4 6 6 Zinc-containing composite slurry 3 2 3 4

[0084] Comparative Example 1

[0085] The only difference between this comparative example and Example 1 is that quartz powder of equal mass is used instead of diatomaceous earth.

[0086] Comparative Example 2

[0087] The only difference between this comparative example and Example 1 is that quartz powder of equal mass is used instead of expanded perlite.

[0088] Comparative Example 3

[0089] The only difference between this comparative example and Example 1 is that slaked lime powder of equal mass is used to replace building gypsum.

[0090] Comparative Example 4

[0091] The only difference between this comparative example and Example 1 is that the proportion of building gypsum is adjusted to 20%, and the proportion of slaked lime powder is reduced by the same amount accordingly.

[0092] Comparative Example 5

[0093] The only difference between this comparative example and Example 1 is that the titanium-containing composite slurry is not prepared, and the corresponding raw materials of the titanium-containing composite slurry are directly mixed with other raw materials.

[0094] Comparative Example 6

[0095] The only difference between this comparative example and Example 1 is that the zinc-containing composite slurry is not prepared, and the corresponding raw materials of the zinc-containing composite slurry are directly mixed with other raw materials.

[0096] The relevant performance test results of Examples 1 to 4 are shown in Table 2, and the relevant performance test results of Comparative Examples 1 to 6 are shown in Table 3.

[0097] The test method is as follows:

[0098] Flexural strength, moisture expansion rate: GB / T7019-2014

[0099] Formaldehyde emission, heavy metal content: GB18584-2001

[0100] Total Volatile Organic Compounds: HJ571-2010

[0101] Formaldehyde purification performance, formaldehyde purification effect durability, humidity control performance: JC / T2177-2013

[0102] Antibacterial performance, antibacterial durability: JC / T897-2014

[0103] Table 2 Related performance test results of Examples 1 to 4

[0104]

[0105]

[0106] Table 3 Comparative Examples 1 to 6 Related Performance Test Results

[0107]

[0108]

[0109] It can be seen from Tables 2 and 3 that the comprehensive effect achieved by Example 1 of the present invention is outstanding. In Comparative Example 1, diatomaceous earth is not used. The density of the product increases significantly, but the strength does not increase significantly, and the humidity control performance of the product decreases significantly. The reason is that diatomaceous earth has a porous structure and activity, and the crystal strength and moisture absorption and adsorption performance after its hydration reaction are better. In Comparative Example 2, expanded perlite is not used. Although there is no significant difference in the physical and mechanical properties of the product, the humidity control performance of the finished product decreases. The reason is that expanded perlite also has porous humidity control performance. In Comparative Example 3, building gypsum is not used. Its density increases, its strength decreases, and the humidity control performance of the finished product decreases. The reason is that the presence of a small amount of gypsum promotes the hydration reaction process and produces more crystals with more reasonable pore structures. In Comparative Example 4, the amount of building gypsum used is large, and the mechanical properties of the product decrease significantly. The reason is that the presence of excessive gypsum causes more bad crystals in the hydrated product, affecting the product strength. In Comparative Example 5, the titanium-containing composite slurry was not prepared, resulting in decreased mechanical properties, a significant reduction in the titanium oxide content, and reduced purification performance. This was due to the simple addition of ultrafine titanium oxide powder, which was not fully retained on the slab during the slurry flow process. In Comparative Example 6, the zinc-containing composite slurry was not prepared, making it impossible to achieve uniform atomization and spraying, resulting in a poor product appearance and reduced antibacterial properties.

[0110] The present invention uses slaked lime powder, building gypsum, diatomaceous earth, and quartz powder as the main silicon-calcium materials, and can produce well-crystallized calcium silicate crystals through hydration reaction. Then, through the use of bleached coniferous wood fiber, the light weight and high strength performance of the product can be ensured. Titanium-containing composite slurry, zinc-containing composite slurry and expanded perlite are added during the manufacturing process. In addition to the characteristics of light weight and high strength, the final product also has purification, humidity control and antibacterial properties. The process of making titanium-containing composite slurry in the present invention is necessary. Through continuous stirring, the micro-flocculation effect of titanium dioxide ultrafine powder and aluminum hydroxide ultrafine powder and the gel-forming suspension effect of bentonite ultrafine powder are fully exerted. The three materials become a simple complex, which can fully reside in the process of felt cloth slurry dehydration and forming cylinder forming dehydration, and will not be carried away by water, thereby fully ensuring its effective content in the final product. The present invention requires a process for preparing a zinc-containing composite slurry. The zinc oxide ultrafine powder and the silica fume ultrafine powder are fully emulsified and compounded, so that the silica fume becomes a good carrier of the zinc oxide ultrafine powder. The slurry has good composite uniformity and fluidity, and can be conveniently added by atomization and spraying. Moreover, the relevant components can be fully retained during the molding and dehydration process of the molding cylinder and will not be carried away by water, thereby fully ensuring their effective content in the final product.

[0111] The actual comparison diagram of the calcium silicate board prepared in Example 1 of the present invention and the existing calcium silicate board is as follows: Figure 1 As shown, Figure 1 a in corresponds to Example 1, Figure 1b in the figure corresponds to the existing calcium silicate board. Figure 1 The calcium silicate board produced by the present invention is aesthetically pleasing and requires no surface coating. Existing calcium silicate boards are commonly used and generally require surface coating before use. The polished surface of the present invention is bright and hard, thanks to the presence of silica fume in the zinc-containing composite slurry sprayed onto the surface. This has an extremely small particle size, high reactivity, and a denser reactant. The closed-pore perlite also creates a decorative effect with gray specks.

[0112] Example 5

[0113] Mix general bleached coniferous pulp with water to obtain a mixed pulp with a mass concentration of 3%, and beat it to prepare a pulp with a beating degree of 28°SR and a wet weight of 11g for later use; prepare composite powder in a ratio of 50% titanium dioxide of 200-400nm, 30% aluminum hydroxide of 600-700nm, and 20% bentonite of 800-1000nm, add water and hydraulically stir for 4 hours to prepare a titanium-containing composite pulp with a solid content of 15% for later use; prepare composite powder in a ratio of 35% zinc oxide of 60-80nm and 65% silica fume of 200-400nm, add water and emulsify and stir for 0.5h to prepare a zinc-containing composite pulp with a solid content of 4% for later use; soak the expanded perlite in an appropriate amount of water for 4 hours and set aside.

[0114] After mixing all materials except the zinc-containing composite slurry in proportion, water is added and stirred until the solids content reaches 13%. The slurry is then flowed to form a thin layer with a thickness of 0.8 mm. The thin layers are then stacked using a forming cylinder to form an 8 mm thick slab. During the first three layers of the stacking process, the zinc-containing composite slurry (slaked lime powder, building gypsum, quartz powder, diatomaceous earth, bleached coniferous wood fiber, basalt fiber, expanded perlite, titanium-containing composite slurry, and zinc-containing composite slurry, in a dry weight ratio of 30:8:30:15:4:3:1:5:2) is continuously and evenly sprayed in using an atomizing spray device according to the formula ratio.

[0115] After the slabs are formed, they are stacked in a mold and placed in a pre-curing room for 10 hours at a temperature of 60°C and a humidity of 98%. After pre-curing, they are demolded and placed in an autoclave for curing. The autoclave curing schedule is as follows: 4 hours of increasing the pressure to 1.2 MPa, 5 hours of maintaining the pressure at 200°C, and 4 hours of reducing the pressure before exiting the autoclave. After exiting the autoclave, they are dried at 120°C to a moisture content of 8% by weight. The surface is then polished in a polishing machine to produce calcium silicate boards with purifying, humidity-regulating, and antibacterial properties.

[0116] Example 6

[0117] Mix general bleached coniferous pulp with water to obtain a mixed pulp with a mass concentration of 3%, and beat it to prepare a pulp with a beating degree of 25°SR and a wet weight of 12g for later use; prepare composite powder according to the ratio of 45% of 100-250nm titanium dioxide, 40% of 600-800nm ​​aluminum hydroxide, and 15% of 500-800nm ​​bentonite, add water and hydraulically stir for 4 hours to prepare a titanium-containing composite pulp with a solid content of 12% for later use; prepare composite powder according to the ratio of 20% of 10-40nm zinc oxide and 80% of 350-400nm silica fume, add water and emulsify and stir for 0.5h to prepare a zinc-containing composite pulp with a solid content of 6% for later use; soak the expanded perlite with an appropriate amount of water for 4 hours and set aside.

[0118] After mixing all materials except the zinc-containing composite slurry in proportion, water is added and stirred until the solids content reaches 16%. The slurry is then flowed to form a thin layer with a thickness of 1.0 mm. The thin layers are then stacked using a forming cylinder to form a slab with a thickness of 10 mm. During the first three layers of the stacking process, the zinc-containing composite slurry (slaked lime powder, building gypsum, quartz powder, diatomaceous earth, bleached coniferous wood fiber, basalt fiber, expanded perlite, titanium-containing composite slurry, and zinc-containing composite slurry, in a dry weight ratio of 26:8:30:15:4:2:1:5:3) is continuously and evenly sprayed in using an atomizing spray device according to the formula ratio.

[0119] After the slabs are formed, they are stacked in a mold and placed in a pre-curing room for 6 hours at a temperature of 90°C and a humidity of 96%. After pre-curing, they are demolded and placed in an autoclave for curing. The autoclave curing schedule is as follows: 4 hours of increasing the pressure to 0.8 MPa, 10 hours of maintaining the pressure at 160°C, and 4 hours of reducing the pressure before exiting the autoclave. After exiting the autoclave, they are dried at 120°C to a moisture content of 8% by weight. The surface is then polished in a polishing machine to produce calcium silicate board with purifying, humidity-regulating, and antibacterial properties.

[0120] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0121] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a calcium silicate board with purification, humidity control and antibacterial properties, characterized in that: The steps include: 1) mixing slaked lime powder, building gypsum, quartz powder, diatomaceous earth, bleached coniferous wood fiber, basalt fiber, expanded perlite and titanium-containing composite slurry with water to obtain a mixed slurry, and flowing the mixed slurry to form a thin material layer; 2) spraying the zinc-containing composite slurry onto the surface of the thin material layer to obtain a modified thin material layer; 3) After stacking the modified thin material layer and the thin material layer, pre-curing, autoclaving curing and polishing are sequentially performed to obtain a calcium silicate board with purification, humidity control and antibacterial properties.

2. The method for preparing a calcium silicate board with purification, humidity control and antibacterial properties according to claim 1, characterized in that: The mass ratio of the slaked lime powder, building gypsum, quartz powder, diatomaceous earth, bleached coniferous wood fiber, basalt fiber, expanded perlite, titanium-containing composite pulp and zinc-containing composite pulp is 24-30:5-8:30-40:12-20:3-8:2-5:1-2:4-6:2-4 on a dry weight basis.

3. The method for preparing a calcium silicate board with purification, humidity control and antibacterial properties according to claim 2, characterized in that: The solid content of the mixed slurry in step 1) is 13-16%; The thickness of the thin material layer is 0.8-1 mm.

4. The method for preparing a calcium silicate board having purification, humidity control and antibacterial properties according to any one of claims 1 to 3, characterized in that: The bleached coniferous wood fiber in step 1) is obtained by beating bleached coniferous wood pulp; The beating degree of the pulping is 25-30°SR.

5. The method for preparing a calcium silicate board with purification, humidity control and antibacterial properties according to claim 4, characterized in that: The preparation method of the titanium-containing composite slurry in step 1) is: Mixing titanium dioxide, aluminum hydroxide, bentonite and water to obtain titanium-containing composite slurry; The solid content of the titanium-containing composite slurry is 10-20%; The mass ratio of titanium dioxide, aluminum hydroxide and bentonite is 30-50:30-50:10-30; The particle size of the titanium dioxide is 100 to 500 nm; the particle sizes of the aluminum hydroxide and bentonite are independently 500 to 1000 nm.

6. The method for preparing a calcium silicate board with purification, humidity control and antibacterial properties according to claim 5, characterized in that: The preparation method of the zinc-containing composite slurry in step 2) is: Mixing zinc oxide, silica fume and water to obtain zinc-containing composite slurry; The solid content of the zinc-containing composite slurry is 3 to 8%; The mass ratio of zinc oxide to silica fume is 20-40:60-80; The particle size of the zinc oxide is 10-100 nm, and the particle size of the silica fume is 100-500 nm.

7. The method for preparing a calcium silicate board with purification, humidity control and antibacterial properties according to claim 6, characterized in that: The stacking in step 3) includes stacking multiple modified thin material layers with multiple thin material layers; The thickness of the stacked slabs is 5 to 15 mm.

8. The method for preparing a calcium silicate board with purification, humidity control and antibacterial properties according to claim 7, characterized in that: The stacked slab contains three modified thin material layers.

9. The method for preparing a calcium silicate board with purification, humidity control and antibacterial properties according to claim 7 or 8, characterized in that: The pre-curing temperature in step 3) is 60-90°C, the humidity is ≥95%, and the time is 6-10 hours; In step 3), the pressure of autoclaving is 0.8-1.2 MPa, the time is 5-10 hours, and the temperature is 160-200°C.

10. The calcium silicate board having purification, humidity control and antibacterial properties prepared by the preparation method according to any one of claims 1 to 9.

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