Magnesium gel fireproof plate and preparation method thereof

Abstract

The invention relates to the technical field of fireproof materials, and provides a magnesium gel fireproof plate and a preparation method thereof. The method comprises the following steps: mixing first raw materials containing magnesium chloride, a first filler and sodium hydroxide to obtain a first mixture; the filler comprises wood flour; adding water into the first mixture in batches, stirring and mixing to obtain a second mixture; adding a second raw material containing light calcined magnesia into the second mixture, and mixing for less than 30 minutes to obtain a third mixture; adding a third raw material containing a second filler into the third mixture, and mixing to obtain a fourth mixture; and putting the fourth mixture into a mold, and curing to obtain the magnesium gel fireproof plate. According to the invention, the wood flour is added into the magnesium cementing material, so that cyclic utilization of resources is realized, sodium hydroxide is introduced while the wood flour is added, a step-by-step feeding method is optimized, the maintenance time is greatly shortened while stable improvement of mechanical properties is realized, and the magnesium cementing material also has fireproof, waterproof and excellent environment-friendly properties and has huge application potential.

Description

Technical Field

[0001] The invention relates to the technical field of fireproof materials, and in particular to a magnesium gelled fireproof board and a preparation method thereof. Background Art

[0002] As people's requirements for living environment safety and quality of life continue to increase, and the performance requirements of materials in the construction, furniture and other industries are becoming increasingly stringent, the quality and safety of artificial boards, as the main materials for interior decoration and furniture manufacturing, have received widespread attention. Traditional artificial boards, such as plywood and particleboard, often require a large amount of adhesives in the production process. These adhesives often contain harmful substances such as formaldehyde, and long-term release will pose a potential threat to human health. At the same time, most artificial boards are based on wood materials, which are prone to deformation, expansion, and even cracking in humid environments, and the edge banding strips fall off, which seriously affects their use effect. In addition, boards used in public places such as hospitals, schools, and libraries also have new requirements for fire resistance.

[0003] To sum up, developing an artificial board that has excellent fire and water resistance and is formaldehyde-free and environmentally friendly not only meets the current market demand for high-performance, environmentally friendly materials, but is also an important direction for promoting the transformation and upgrading of the artificial board industry and achieving sustainable development.

[0004] In this context, low-cost artificial board products that solve fire prevention, water resistance and environmental protection problems at the same time have become a research hotspot. In order to improve the fire resistance and water resistance of the board at the same time, a composite flame retardant and waterproof agent can be added to the board, which usually contains inorganic flame retardant components and waterproof components. These components can release inert gas at high temperature to block combustion, and form a waterproof layer on the surface or inside of the board to prevent water penetration, but this is easy to increase the production cost of the board. In order to further reduce formaldehyde or even achieve formaldehyde-free, the main research direction is to use natural plant adhesives (such as soybean protein glue, starch glue, etc.) to replace traditional formaldehyde adhesives. Although natural adhesives are excellent in environmental protection, their bonding strength and water resistance are insufficient, which makes the board easy to crack, deform or absorb water and swell during use. Magnesium cementitious materials, as an inorganic adhesive, can also achieve waterproof, fire resistant and formaldehyde-free effects, but it takes a long time to reach the initial setting strength and final strength, and it is easy to agglomerate after being doped with wood fibers, resulting in unstable mechanical properties, which limits the application of magnesium cementitious materials in fireproof boards. Summary of the invention

[0005] The present invention provides a magnesium gelled fireproof board and a preparation method thereof. Through the self-developed board formula and process, the average static bending strength of the board reaches above 5.3MPa, and the average elastic modulus reaches above 5000MPa, meeting the performance requirements of building and decorative materials, and having fireproof, water-resistant and environmentally friendly properties. In addition, the formula also utilizes industrial waste such as fly ash, greatly shortens the processing time, reduces costs and realizes the recycling of resources.

[0006] In a first aspect, the present invention provides a method for preparing a magnesium gelled fireproof board, comprising: Mixing a first raw material including magnesium chloride, a first filler and sodium hydroxide to obtain a first mixture; wherein the first filler includes wood powder; adding water in batches to the first mixture and stirring to obtain a second mixture; adding a second raw material containing light-burned magnesium oxide to the second mixture and mixing for less than 30 minutes to obtain a third mixture; adding a third raw material containing a second filler into the third mixture and mixing to obtain a fourth mixture; The fourth mixture is placed in a mold and cured to obtain the magnesium gelled fireproof board.

[0007] As mentioned above, magnesium cementitious materials have certain advantages in terms of fire prevention, water resistance and environmental protection. However, when used in the preparation of fireproof boards, the use of wood powder will cause the problem of unstable mechanical properties of the fireproof boards. In order to promote the dispersion of wood powder in the system and avoid unstable mechanical properties caused by agglomeration, the present invention first optimizes the ratio of magnesium chloride and magnesium oxide. It is found that although optimizing the ratio of the two is beneficial to improving mechanical properties, such as average static bending strength and average elastic modulus, the initial setting time is relatively long, and the time required to reach the initial setting strength and final strength is relatively long.

[0008] Based on this, the present invention introduces sodium hydroxide at the same time when adding wood powder through in-depth research. On the one hand, the extract and lignin in the wood powder are partially dissolved by the action of sodium hydroxide, and the porosity inside the wood is improved, so that the subsequent wood powder and magnesium cementitious material form a better interpenetrating network structure, and the mechanical properties of the board are improved. On the other hand, the first raw material containing magnesium chloride, the first filler containing wood powder and sodium hydroxide are premixed and then water is added. While the premixing is more uniform, the exothermic reaction of magnesium chloride and sodium hydroxide with water is used during the water addition process to further accelerate and strengthen the sodium hydroxide dissolving the extract and lignin in the wood powder, and the mechanical properties are stably improved, and the processing time is avoided to be too long, and the wood does not need to be processed separately, so that the cost is saved. Further, the present invention also adds light-burned magnesium oxide and the third raw material containing the second filler separately, and controls the mixing time of light-burned magnesium oxide to be within 30min, because: the initial setting time after the mixing of magnesium chloride, magnesium oxide and water is generally within 120min, and the mixing is completed within 30min to keep the mixture in a thick emulsion or cream, so that the third raw material can be mixed uniformly later. If it is not completed within 30 minutes, the mechanical properties of the resulting fireproof board will decrease and become unstable.

[0009] In addition, the wood powder in the present invention is also used to increase the strength-to-weight ratio of the magnesium gelled fireproof board, but the wood powder cannot be added too much, otherwise it will affect the mechanical properties and flame retardant properties. The mass ratio of the magnesium chloride to the wood powder is 10:20-40, preferably 10:30; the mass ratio of the wood powder to the sodium hydroxide is 30:3-7, preferably 30:5.

[0010] According to the preparation method of the magnesium gelled fireproof board as described above provided by the present invention, the curing includes vibrating in a mold, taking out the preliminary blank after curing for 1 to 2 days, and continuing to cure the preliminary blank for more than 7 days. During the continued curing period, the surface of the preliminary blank is sprayed with water to keep the surface moist.

[0011] The reason why the present invention keeps the surface moist is that the hydration process is a continuous process accompanied by slow heat release. When the water evaporates, the whiskers of the 518 crystals formed will be destroyed, and this structure of the 518 phase whiskers is the key to forming an interpenetrating network structure. Therefore, keeping the surface moist will slow down the evaporation rate of water and make the material fully moist, which is beneficial to the progress of the hydration reaction, thereby improving the mechanical properties of the magnesium gelled fireproof board.

[0012] The above-mentioned compaction is to reduce internal bubbles.

[0013] The role of fly ash in the present invention is mainly to increase the number of micropores in the material, reduce the thickness of the hydration layer, and form a denser interpenetrating network structure, thereby increasing the elasticity of the magnesium gelled fireproof board. However, the amount of fly ash added should not be too large, otherwise it will hinder the hydration reaction process and have a negative impact on the comprehensive performance of the magnesium gelled fireproof board. According to the preparation method of the magnesium gelled fireproof board as described above provided by the present invention, the first filler also includes fly ash; the mass ratio of the magnesium chloride to the fly ash is 10:5~15; preferably 10:10.

[0014] The hydration reaction mechanism of the fireproof board of the present invention mainly involves the chemical reaction between magnesium oxide and water and components such as magnesium chloride. It mainly includes that magnesium oxide will undergo a hydration reaction in the presence of water to generate magnesium hydroxide, and the hydrogen ions generated by the hydrolysis of magnesium chloride can neutralize the alkalinity of magnesium hydroxide, thereby promoting further hydration of magnesium oxide, and generating a complex salt with cementing properties. In order to make the mechanical properties and fireproof properties of the fireproof board better, the present invention regulates the mass ratio of the magnesium chloride and the light-burned magnesium oxide. According to the preparation method of the magnesium cemented fireproof board as described above provided by the present invention, the mass ratio of the magnesium chloride and the light-burned magnesium oxide is 10:10~25, preferably 10:20.

[0015] Silane coupling agent is a special organosilicon compound that can act as a "molecular bridge" to improve the interface between the second filler (such as kaolin, iron oxide, etc.) and the organic matter. The present invention regulates the mass ratio of the magnesium chloride and the silane coupling agent, which can significantly improve the mechanical properties of the fireproof board, increase the static bending strength and elastic modulus. According to the preparation method of the magnesium gelled fireproof board as described above provided by the present invention, the third raw material also includes a silane coupling agent; the mass ratio of the magnesium chloride and the silane coupling agent is 10:1~2, preferably 10:1.

[0016] In order to reasonably control the initial setting time, the silane coupling agent is preferably KH560.

[0017] Accordingly, after adding the silane coupling agent, the initial setting time of the magnesium gelling material will be shortened to about 15 minutes, so it must be quickly mixed before reaching the initial setting. That is, the third raw material is added to the third mixture in batches and mixed for less than 15 minutes to obtain the fourth mixture; if the third raw material is not completed within 15 minutes, the mechanical properties of the obtained fireproof board will be reduced and unstable.

[0018] Generally, kaolin is a natural clay mineral with a high melting point and can form a stable ceramic phase at high temperatures. In fireproof boards, kaolin can form a hard ceramic layer at high temperatures, which plays a role in heat insulation and flame retardancy. Studies have found that in the invention, kaolin further increases the interfacial bonding effect between the various materials. According to the preparation method of the magnesium gelled fireproof board as described above provided by the present invention, the second filler includes kaolin; the mass ratio of the magnesium chloride to the kaolin is 10:10~20, preferably 10:10.

[0019] Generally, iron oxide has high thermal stability and can improve the heat resistance of the material in the fireproof board. It can form a stable oxide layer at high temperature to prevent further oxidation and decomposition of the material. Studies have found that in the invention, iron oxide can also promote hydration reactions and reduce the curing time to reach the final strength. According to the preparation method of the magnesium gelled fireproof board as described above provided by the present invention, the second filler also includes iron oxide; the mass ratio of the magnesium chloride to the iron oxide is greater than or equal to 10:3.

[0020] Since the third raw material also includes materials such as kaolin and iron oxide, the initial setting time will be further shortened. Therefore, the third raw material is added to the third mixture in batches and the mixing time is preferably controlled to be less than 10 minutes to obtain a fourth mixture.

[0021] According to the method for preparing the magnesium gelled fireproof board as described above provided by the present invention, the first raw materials are mixed in a horizontal mixer with a beating bar to obtain a first mixture.

[0022] According to the preparation method of the magnesium gelled fireproof board as described above provided by the present invention, water is added to the first mixture in batches and stirred and mixed in a planetary mixer, the stirring speed is less than or equal to 20r / min, the stirring and mixing time is more than 30min, and the water addition speed is controlled so that the system temperature is 85~95°C to obtain a second mixture.

[0023] The horizontal mixer with a breaking rod of the present invention mixes the first raw material, which can effectively prevent the wood powder and fly ash from agglomerating.

[0024] According to the preparation method of the magnesium gelled fireproof board as described above provided by the present invention, the raw materials include, by weight: 10 parts of magnesium chloride, 20-40 parts of wood powder, 5-15 parts of fly ash, 5-7 parts of sodium hydroxide, 35-45 parts of water, 15-25 parts of light-burned magnesium oxide, 1-1.5 parts of silane coupling agent, 10-11 parts of kaolin and 3-4 parts of iron oxide.

[0025] In a second aspect, the present invention further provides a magnesium gelled fireproof board, which is prepared by the preparation method of the magnesium gelled fireproof board as described above.

[0026] The present invention provides a magnesium cementitious fireproof board and a preparation method thereof, wherein wood powder is added to the magnesium cementitious material to realize the recycling of resources, and sodium hydroxide is introduced simultaneously when the wood powder is added, and the step-by-step feeding method is optimized, thereby realizing stable improvement of mechanical properties while greatly shortening the curing time, and having fireproof, water-resistant and excellent environmental protection properties, and having great application potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the present invention or 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 some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 It is a structural schematic diagram of the mixer provided by the present invention.

[0029] Description of the drawings: 1: mixture, 2: mixing chamber, 3: beating rod. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] Combine the following Figure 1 The invention describes a magnesium gelled fireproof board and a preparation method thereof.

[0032] If no specific techniques or conditions are specified in the examples, the techniques or conditions described in the literature in the field or the product instructions are used. If no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be purchased through regular channels.

[0033] Example 1 A method for preparing a magnesium gelled fireproof board, the steps of which are as follows by weight: (1) 10 parts of magnesium chloride, 30 parts of wood flour, 5 parts of sodium hydroxide and 10 parts of fly ash are mixed uniformly in a horizontal mixer with a beating bar to obtain a first mixture.

[0034] Among them, Figure 1As shown, the horizontal mixer with a beating rod includes a mixing chamber 2 and a beating rod 3 located in the mixing chamber 2. In the present invention, the mixture 1 is added into the mixing chamber 2, and the mixing chamber 2 is rotated so that the mixture 1 therein is evenly stirred under the action of the beating rod 3.

[0035] (2) 40 parts of water are added in batches to the first mixture prepared in step (1), and stirred evenly in a planetary mixer to obtain a second mixture; wherein the stirring speed is controlled to be 20 r / min, the temperature of the system is controlled to be around 90° C. during the process of adding water in batches, and the mixing time is 35 min.

[0036] (3) Gradually add 20 parts of light-burned magnesium oxide to the second mixture in step (2), mix evenly, and mix for 30 minutes to obtain a third mixture.

[0037] (4) 1 part of KH560 silane coupling agent, 10 parts of kaolin and 3 parts of ferric oxide were mixed evenly and then added to the third mixture of step (3) in batches. This process was completed within 10 minutes to obtain a fourth mixture in the form of a thick cream.

[0038] (5) The fourth mixture of step (4) is placed on a mold, compacted, and cured for 1 day.

[0039] (6) The blank is removed from the mold and cured for another 7 days. During the curing period, the surface needs to be sprayed with water to keep it moist.

[0040] (7) Sanding and trimming to obtain magnesium cementitious fireproof board.

[0041] Example 2 A method for preparing a magnesium gelled fireproof board is basically the same as that of Example 1, except that step (6) is as follows: (6) The preform is removed from the mold and is cured in air at room temperature for 7 days, i.e., no moisture is provided during the curing period.

[0042] Comparative Example 1 A method for preparing a magnesium gelled fireproof board is basically the same as that of Example 1, except that the preparation process of the second mixture is as follows: 10 parts of magnesium chloride, 30 parts of wood powder, 5 parts of sodium hydroxide, 10 parts of fly ash and 40 parts of water are mixed evenly in a planetary mixer to obtain a second mixture; wherein the stirring speed is controlled to be 20 r / min, the temperature of the system is controlled to be 90° C., and the mixing time is 35 min.

[0043] The magnesium gelled fireproof boards obtained in Comparative Example 1 and Examples 1-2 were tested, and the results are shown in Tables 1-2. The test methods for static bending strength and elastic modulus refer to GB / T 17657-2022.

[0044] Table 1

[0045] Table 2

[0046] From the results shown in Tables 1 and 2, it can be seen that the mechanical properties of the materials mixed together are poor and the variance is large, indicating that the mixing is uneven. After water spraying and moisturizing, the mechanical properties are improved, among which the static bending strength is significantly improved.

[0047] Example 3 A method for preparing a magnesium gelled fireproof board is basically the same as that of Example 2, except that step (6) is as follows: (6) The preform is removed from the mold and cured in air at room temperature for 14 days, i.e., no moisture is provided during the curing period.

[0048] Example 4 A method for preparing a magnesium gelled fireproof board is basically the same as that of Example 2, except that step (6) is as follows: (6) The preform is removed from the mold and is cured in air at room temperature for 30 days, i.e., no moisture is provided during the curing period.

[0049] Example 5 A method for preparing a magnesium gelled fireproof board is basically the same as that of Example 2, except that ferric oxide is not added.

[0050] Example 6 A method for preparing a magnesium gelled fireproof board is basically the same as that of Example 3, except that ferric oxide is not added.

[0051] Example 7 A method for preparing a magnesium gelled fireproof board is substantially the same as that of Example 4, except that ferric oxide is not added.

[0052] The magnesium gelled fireproof boards obtained in Examples 2 to 7 were tested, and the results are shown in Table 3 below.

[0053] Table 3

[0054] From the results shown in Table 3, it can be seen that after adding 3% iron oxide, the average static bending strength and elastic modulus at 7 days of curing are close to the indicators of the formula without iron oxide at 14 days of curing. From the comparison of the above different curing days, it can also be seen that the effect of iron oxide on improving the mechanical properties at 7 days of curing is more significant. Therefore, after adding iron oxide, curing for 7 days can be carried out for the next step.

[0055] Example 8 A method for preparing a magnesium gelled fireproof board is basically the same as that of Example 7, except that the amount of kaolin is adjusted to 20 parts.

[0056] Example 9 A method for preparing a magnesium gelled fireproof board is basically the same as that of Example 7, except that kaolin is not added.

[0057] The magnesium gelled fireproof boards obtained in Examples 7 to 9 were tested, and the results are shown in Table 4 below.

[0058] Table 4

[0059] From the results shown in Table 4, it can be seen that kaolin further regulates the mechanical properties of the material.

[0060] Example 10 A method for preparing a magnesium gelled fireproof board is basically the same as that of Example 9, except that the amount of KH560 silane coupling agent is adjusted to 2 parts.

[0061] Embodiment 11 A method for preparing a magnesium gelled fireproof board is substantially the same as that of Example 9, except that no KH560 silane coupling agent is added.

[0062] The magnesium gelled fireproof boards obtained in Examples 9 to 11 were tested, and the results are shown in Table 5 below.

[0063] Table 5

[0064] From the results shown in Table 5, it can be seen that although adding KH560 will increase the static bending strength and elastic modulus, considering the high cost of KH560, the mass ratio of the magnesium chloride to the silane coupling agent is preferably 10:1.

[0065] Example 12 A method for preparing a magnesium gelled fireproof board is basically the same as that of Example 11, except that 3 parts of sodium hydroxide are added in step (1).

[0066] Embodiment 13 A method for preparing a magnesium gelled fireproof board is basically the same as that of Example 11, except that 7 parts of sodium hydroxide are added in step (1).

[0067] Comparative Example 2 A method for preparing a magnesium gelled fireproof board is basically the same as Example 11, except that no sodium hydroxide is added.

[0068] The magnesium gelled fireproof boards obtained in Examples 11 to 13 and Comparative Example 2 were tested, and the results are shown in Table 6 below.

[0069] Table 6

[0070] From the results shown in Table 6, it can be seen that although increasing sodium hydroxide increases the static bending strength and elastic modulus, considering that the performance improvement from 5 parts to 7 parts is not as good as that from 3 parts to 5 parts, and the cost of sodium hydroxide is relatively high, 5 parts is preferred.

[0071] Comparative Examples 3~10 A method for preparing a magnesium gelled fireproof board is basically the same as that of Comparative Example 2, except that the amounts of fly ash and wood powder are as shown in Table 7 below.

[0072] Table 7

[0073] The magnesium gelled fireproof boards obtained in Comparative Examples 3 to 10 were tested, and the results are shown in Table 8 below.

[0074] Table 8

[0075] From the results shown in Tables 7 and 8, it can be seen that wood powder cannot be added too much, otherwise it will affect the mechanical properties. The amount of fly ash added should not be too large, otherwise it will hinder the hydration reaction process and have a negative impact on the mechanical properties of the magnesium cementitious fireproof board.

[0076] Comparative Example 11 A method for preparing a magnesium gelled fireproof board, the steps of which are as follows by weight: (1) 10 parts of magnesium chloride and 10 parts of light-burned magnesium oxide are mixed to obtain a mixture.

[0077] (2) Add 30 parts of water in batches to the mixture in step (1), control the system temperature at 90°C, and mix for 85 minutes to obtain a thick creamy material.

[0078] (3) Place the thick creamy material from step (2) on a mold, compact it, and cure it for 1 day.

[0079] (4) The preform is removed from the mold and is cured in air at room temperature for 30 days, i.e., no moisture is provided during the curing period.

[0080] (5) Sanding and trimming to obtain magnesium cementitious fireproof board.

[0081] Comparative Example 12 A method for preparing a magnesium gelled fireproof board is basically the same as that of comparative example 11, except that the amount of light-burned magnesium oxide is adjusted to 15 parts.

[0082] Comparative Example 13 A method for preparing a magnesium gelled fireproof board is basically the same as that of comparative example 11, except that the amount of light-burned magnesium oxide is adjusted to 20 parts.

[0083] Comparative Example 14 A method for preparing a magnesium gelled fireproof board is basically the same as that of comparative example 11, except that the amount of light-burned magnesium oxide is adjusted to 25 parts.

[0084] The magnesium gelled fireproof boards obtained in Comparative Examples 11 to 14 were tested, and the results are shown in Table 9 below.

[0085] Table 9

[0086] From the results shown in Table 9, it can be seen that optimizing the ratio of magnesium chloride and magnesium oxide is beneficial to improving the mechanical properties, such as the average static bending strength and the average elastic modulus, but the initial setting time is longer.

[0087] The water resistance and flame retardancy of the magnesium gelled fireproof board obtained in Example 1 were tested, and the results are shown in Table 10 below.

[0088] Table 10

[0089] As can be seen from Table 10 above, it has excellent waterproof performance and can reach A2 fireproof grade. The reason why formaldehyde release is that wood naturally contains some formaldehyde, which is a natural substance component.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a magnesium gelled fireproof board, characterized in that: include: A first raw material including magnesium chloride, a first filler and sodium hydroxide is mixed to obtain a first mixture; the first filler includes wood powder; the mass ratio of the magnesium chloride to the wood powder is 10:20-40; the mass ratio of the wood powder to the sodium hydroxide is 30:3-7; adding water in batches to the first mixture and stirring to obtain a second mixture; adding a second raw material containing light-burned magnesium oxide to the second mixture and mixing for less than 30 minutes to obtain a third mixture; adding a third raw material containing a second filler into the third mixture and mixing to obtain a fourth mixture; The fourth mixture is placed in a mold and cured to obtain the magnesium gelled fireproof board.

2. The method for preparing the magnesium gelled fireproof board according to claim 1, characterized in that: The curing includes compacting the preform in a mold, taking out the preform after curing for 1 to 2 days, and continuing to cure the preform for more than 7 days. During the continued curing, water is sprayed on the surface of the preform to keep the surface moist.

3. The method for preparing the magnesium gelled fireproof board according to claim 2, characterized in that: The first filler also includes fly ash; the mass ratio of the magnesium chloride to the fly ash is 10:5-15.

4. The method for preparing the magnesium gelled fireproof board according to claim 3, characterized in that: The mass ratio of the magnesium chloride to the light-burned magnesium oxide is 10:10-25.

5. The method for preparing the magnesium gelled fireproof board according to claim 4, characterized in that: The third raw material also includes a silane coupling agent; the mass ratio of the magnesium chloride to the silane coupling agent is 10:1-2.

6. The method for preparing the magnesium gelled fireproof board according to claim 5, characterized in that: The second filler includes kaolin; the mass ratio of the magnesium chloride to the kaolin is 10:10-20.

7. The method for preparing the magnesium gelled fireproof board according to claim 6, characterized in that: The second filler also includes iron oxide; the mass ratio of the magnesium chloride to the iron oxide is greater than or equal to 10:

3.

8. The method for preparing the magnesium gelled fireproof board according to claim 7, characterized in that: The first raw materials are mixed in a horizontal mixer with a beating bar to obtain a first mixture.

9. The method for preparing the magnesium gelled fireproof board according to claim 8, characterized in that: The water is added to the first mixture in batches and stirred and mixed in a planetary mixer at a stirring speed of less than or equal to 20 r / min for a stirring and mixing time of more than 30 min. The water addition speed is controlled so that the system temperature is 85-95° C. to obtain a second mixture.

10. A magnesium gelled fireproof board, characterized in that: The magnesium gelled fireproof board is prepared by the preparation method of any one of claims 1 to 9.

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