Preparation method of fire-resistant wall material capable of automatically decomposing formaldehyde

Abstract

The present invention relates to the technical field of fire-resistant wall materials and discloses a method for preparing a fire-resistant wall material that can automatically decompose formaldehyde, comprising the following steps: (1) mixing MgO and Al2O3, subjecting the mixture to ball milling, ultrasonic treatment, and heating reaction to obtain a porous precursor; (2) mixing the porous precursor with nano-LiF and calcining the mixture under nitrogen protection to obtain a calcined product; (3) loading the calcined product with titanium dioxide nanotubes through a coupling reaction to obtain a fire-resistant wall material. The present invention utilizes the excellent fire-resistant properties of spinel materials and, through the loading of titanium dioxide nanotubes, enables the wall material to catalytically decompose toxic and hazardous substances such as formaldehyde and benzene; by first synthesizing the porous precursor and then adding nano-LiF, the calcination time is greatly shortened and energy loss is reduced while meeting the material properties.

Description

Technical Field

[0001] The present invention belongs to the technical field of fire-resistant walls, and more particularly relates to a method for preparing a fire-resistant wall material capable of automatically decomposing formaldehyde. Background Art

[0002] Formaldehyde has always been a serious problem in home renovations. Even water-soluble paints contain a certain amount of formaldehyde, which evaporates into the air and can be inhaled by humans. Therefore, research is underway to reduce the harmful effects of formaldehyde on the environment and the human body by fixing the formaldehyde in wall paint and ultimately decomposing it.

[0003] The general chemical formula of spinel can be expressed as AO·R2O3, where A represents a divalent element ion, which can be Mg 2+ 、Fe 2+ etc.; R is a trivalent element, which can be Al 3+ 、Fe 3+ Cr 3+ Spinel is an important type of neutral or feather-breaking refractory material. According to the raw materials used and their composition, it can be divided into chrome bricks, chrome-magnesia bricks, magnesia-chrome bricks, and magnesia-alumina spinel refractory materials. Most of them exist in the form of isomorphous solid solution, so they can be used as good refractory wall materials.

[0004] TiO2 is a good photocatalyst, and its mechanism of catalytic formaldehyde decomposition is as follows:

[0005] The catalysis of TiO2 is mainly divided into two steps: the first step is that light greater than or equal to the band gap energy of TiO2 is irradiated on its surface, and then the electrons in the valence band will jump and move to the conduction band. The valence band will generate holes (h + ), on the contrary, the conduction band gets electrons (e - ), thereby generating electron-hole pairs, preparing for the subsequent redox reaction. In the second step, the holes (h + ) reacts with H2O in the air to generate ·OH with strong oxidizing activity, and at the same time, the electrons in the conduction band (e - ) reacts with O2 to produce O2 - , ·H2O2, HOO· and ·OH, etc. These active substances can further undergo redox reactions with pollutants, degrading large molecular pollutants into small molecular pollutants, and then converting them into CO2 and H2O.

[0006] Titanium dioxide degrades formaldehyde primarily through the intermediate product of formic acid (HCOOH). Studies have shown that the electron spin resonance (ESR) method and the spin-electron spin resonance (ST-ESR) method show that the photocatalytic reaction mechanism of methanol is as follows:

[0007] HCHO + OH → CHO + H2O

[0008] ·CHO+·OH→·CHOOH

[0009] CHO+O2 - →HCO3 -

[0010] HCO3 - +H + →HCOOOH

[0011] HCOOOH+HCHO→HCOOH

[0012] HCOOH-H + →HCOO -

[0013] HCOO - +h + →H + + CO2 -

[0014] CO2 - +(·OH,O,h + )→CO2

[0015] In summary, titanium dioxide's use of photocatalysis to remove formaldehyde utilizes the principle of photocatalysis. Under ultraviolet light, formaldehyde can be catalyzed by titanium dioxide to decompose into carbon dioxide and water. Of course, titanium dioxide can also promote the decomposition of nitrogen oxides, aromatic hydrocarbons, and other aldehydes, and has a certain destructive effect on bacterial cell walls. By loading titanium dioxide onto a refractory spinel material, a refractory wall material that can decompose formaldehyde can be obtained, which has certain significance for the environmental protection industry and the decoration industry. Summary of the Invention

[0016] In view of this, the purpose of the present invention is to provide a method for preparing a refractory wall material that can automatically decompose formaldehyde. MgO and Al2O3 are used with nano-level LiF to make a refractory wall material, and finally TiO2 is loaded onto the spinel refractory material, so that the wall has the effect of decomposing formaldehyde and at the same time has certain fire-resistant properties.

[0017] To achieve the above object, the present invention provides a method for preparing a fire-resistant wall material that can automatically decompose formaldehyde, comprising the following steps:

[0018] (1) MgO and Al2O3 are mixed, subjected to ball milling, ultrasonic treatment, and then heated to react to obtain a porous precursor;

[0019] (2) mixing the porous precursor and nano-LiF, and calcining them under nitrogen protection to obtain a calcined product;

[0020] (3) The calcined product is loaded with titanium dioxide nanotubes through a coupling reaction to obtain a refractory wall material.

[0021] During the spinel synthesis stage, the present invention reduces the particle size of the reactants through mechanical ball milling, first synthesizes a porous precursor, and then adds nanoscale LiF. This, while meeting the material properties, aims to reduce the time required for the solid-phase reaction, significantly shorten the calcination time, and reduce energy loss. Titanium dioxide is loaded onto the spinel walls, giving them the ability to catalyze the decomposition of toxic and hazardous substances such as formaldehyde and benzene. Furthermore, titanium dioxide has the ability to destroy bacterial cell walls, thus playing a certain protective role for the health of the residents of the house.

[0022] The present invention uses spinel wall materials to make walls with excellent fire resistance. When a fire occurs, the survival rate of escapees and firefighters can be increased. In addition, the entire process has lower costs, higher efficiency, and less energy consumption.

[0023] Further preferably, the molar ratio of MgO to Al2O3 is 1.5-2.5:1.

[0024] Since the ratio of divalent ions to trivalent ions in spinel refractory materials is 1:2, studies have found that excessive divalent ions are conducive to the formation of spinel.

[0025] More preferably, the particle size after ball milling is 200-700 mesh.

[0026] The smaller the particle size, the higher the reaction efficiency, but the time cost is greater.

[0027] More preferably, the ultrasonication time is 10-30 min.

[0028] The purpose of ultrasound is to disperse the reactants more evenly to facilitate the synthesis of subsequent experiments.

[0029] More preferably, the heating reaction temperature is 180-240° C. and the time is 20-26 h.

[0030] Further preferably, the added amount of the nano-LiF is 0.5-1.5% of the mass of the porous precursor.

[0031] The purpose of adding nano-LiF is to reduce the temperature and time required for the precursor reaction.

[0032] More preferably, the calcination temperature is 700-1100° C. and the calcination time is 1-5 h.

[0033] During the research process, the present invention team found that the calcination time and temperature have a more serious impact on the spinel refractory material. If the temperature is too low, it cannot be synthesized or it will take longer or affect the mechanical properties of the spinel refractory material. If the temperature is too high, the surface of the spinel refractory material is too dense, and the titanium dioxide nanotubes loaded with Pd cannot be loaded on the spinel refractory material again. This is because one end of the Pd nanoparticles loads the titanium dioxide nanotubes, and the other end needs to be loaded in the gap on the surface of the spinel refractory material. The gap is too small to load (Comparative Example 8).

[0034] Further preferably, the coupling reaction is as follows: 3-8 wt% Pd nanoparticles are loaded onto the surface of titanium dioxide nanotubes, and the reaction temperature is 700-900 ° C. under a nitrogen atmosphere for 1.5-3 hours; 3-8 wt% of the loaded titanium dioxide nanotubes are then loaded onto the calcined product, and the reaction temperature is 40-60 ° C. for 5-10 minutes. After the reaction is completed, the reaction is allowed to stand at room temperature for 2-5 hours.

[0035] Further preferably, in step (1), while the MgO and Al2O3 are mixed, CoO is also added and mixed together.

[0036] Further preferably, the added amount of CoO is 1-15% of the total mass of the mixture of MgO and Al2O3.

[0037] The color of the material changes with the reaction temperature and the amount of CoO used. When the CoO content is ≥1% and <3%, the material appears white regardless of temperature. When the CoO content is between 3-10%, the material transitions from light green to light blue, and then from light blue to dark blue by changing the calcination temperature: light green at 700-760°C, light blue at 760-940°C, and dark blue at 940-1100°C. When the CoO content is >10% and ≤15%, and the reaction temperature is higher, the material appears black.

[0038] Compared with the existing technology, the present invention has the following advantages: the walls made of spinel wall materials have excellent fire resistance, and titanium dioxide is loaded onto the spinel walls, so that the walls have the ability to catalytically decompose toxic and harmful substances such as formaldehyde and benzene; by first synthesizing a porous precursor and then adding nano-scale LiF, the calcination time is greatly shortened and energy loss is reduced while meeting the material properties; CoO is added during the synthesis of the spinel wall material, so that the wall itself has color, thereby reducing the amount of paint applied in the later stage and fundamentally reducing the mixing of harmful substances such as formaldehyde and benzene. DETAILED DESCRIPTION

[0039] The technical content and effects of the present invention are further described in detail below with reference to the embodiments, but the present invention is not limited thereto.

[0040] Example 1

[0041] (1) MgO and Al2O3 were mixed in a molar ratio of 2:1 and ground thoroughly in a ball mill until the particle size of the mixture was 600 mesh;

[0042] (2) ultrasonically treating the ground mixture for 20 minutes; placing the ultrasonicated material in a reactor and heating it at 200° C. for 24 hours to obtain a porous precursor;

[0043] (3) After the porous precursor is fully dried, 1 wt% of nano-LiF is added; all reactants are placed in an electric furnace, N2 protective gas is introduced, and the reaction is carried out at a high temperature of 700°C for 4 hours to obtain a calcined product;

[0044] (4) First, 5 wt% Pd nanoparticles and titanium dioxide nanotubes were mixed, and the reaction temperature was maintained at 800 ° C in a nitrogen atmosphere for 2 hours; then, 5 wt% loaded titanium dioxide nanotubes and the calcined product were mixed, and the reaction temperature was 50 ° C for 8 minutes. After the reaction was completed, the mixture was allowed to stand at room temperature for 2 hours to obtain a refractory wall material.

[0045] Example 2

[0046] (1) MgO and Al2O3 were mixed in a molar ratio of 1.5:1 and ground thoroughly in a ball mill until the mixture had a particle size of 500 mesh;

[0047] (2) ultrasonically treating the ground mixture for 25 minutes; placing the ultrasonicated material in a reactor and heating it at 240° C. for 20 hours to obtain a porous precursor;

[0048] (3) After the porous precursor is fully dried, 1.25 wt% of nano-LiF is added; all reactants are placed in an electric furnace, N2 protective gas is introduced, and the reaction is carried out at a high temperature of 800°C for 1.5 hours to obtain a calcined product;

[0049] (4) First, 8 wt% Pd nanoparticles and titanium dioxide nanotubes were mixed, and the reaction temperature was maintained at 700°C in a nitrogen atmosphere for 1.5 hours; then, 8 wt% loaded titanium dioxide nanotubes and the calcined product were mixed, and the reaction temperature was 40°C for 5 minutes. After the reaction was completed, the mixture was allowed to stand at room temperature for 3 hours to obtain a refractory wall material.

[0050] Example 3

[0051] (1) MgO and Al2O3 were mixed in a molar ratio of 2.5:1 and ground thoroughly in a ball mill until the mixture had a particle size of 400 mesh;

[0052] (2) ultrasonically treating the ground mixture for 30 minutes; placing the ultrasonicated material in a reactor and heating it at 180° C. for 26 hours to obtain a porous precursor;

[0053] (3) After the porous precursor is fully dried, 1.5 wt% of nano-LiF is added; all reactants are placed in an electric furnace, N2 protective gas is introduced, and the reaction is carried out at a high temperature of 1000°C for 4 hours to obtain a calcined product;

[0054] (4) First, 6 wt% Pd nanoparticles and titanium dioxide nanotubes were mixed, and the reaction temperature was maintained at 900 ° C for 3 hours in a nitrogen atmosphere; then, 6 wt% loaded titanium dioxide nanotubes and the calcined product were mixed, and the reaction temperature was 50 ° C for 7 minutes. After the reaction was completed, the mixture was allowed to stand at room temperature for 3 hours to obtain a refractory wall material.

[0055] Example 4

[0056] (1) MgO and Al2O3 were mixed in a molar ratio of 2:1, 1%wt CoO was added, and the mixture was fully ground in a ball mill. The particle size of the mixture after grinding was 600 mesh;

[0057] (2) ultrasonically treating the ground mixture for 20 minutes; placing the ultrasonicated material in a reactor and heating it at 200° C. for 24 hours to obtain a porous precursor;

[0058] (3) After the porous precursor is fully dried, 1 wt% of nano-LiF is added; all reactants are placed in an electric furnace, N2 protective gas is introduced, and the reaction is carried out at a high temperature of 800°C for 2 hours to obtain a calcined product;

[0059] (4) First, 3 wt% Pd nanoparticles and titanium dioxide nanotubes were mixed, and the reaction temperature was maintained at 900 ° C in a nitrogen atmosphere for 2.5 hours; then, 3 wt% loaded titanium dioxide nanotubes and the calcined product were mixed, and the reaction temperature was 60 ° C for 10 minutes. After the reaction was completed, the mixture was allowed to stand at room temperature for 2 hours to obtain a refractory wall material.

[0060] Example 5

[0061] (1) MgO and Al2O3 were mixed in a molar ratio of 2:1, 7% wt CoO was added, and the mixture was fully ground in a ball mill. The particle size of the mixture after grinding was 600 mesh;

[0062] (2) ultrasonically treating the ground mixture for 20 minutes; placing the ultrasonicated material in a reactor and heating it at 200° C. for 24 hours to obtain a porous precursor;

[0063] (3) After the porous precursor is fully dried, 1 wt% of nano-LiF is added; all reactants are placed in an electric furnace, N2 protective gas is introduced, and the reaction is carried out at a high temperature of 1100°C for 2 hours to obtain a calcined product;

[0064] (4) First, 8 wt% Pd nanoparticles and titanium dioxide nanotubes were mixed, and the reaction temperature was maintained at 850°C in a nitrogen atmosphere for 2 hours; then, 8 wt% loaded titanium dioxide nanotubes and the calcined product were mixed, and the reaction temperature was 40°C for 5 minutes. After the reaction was completed, the mixture was allowed to stand at room temperature for 4 hours to obtain a refractory wall material.

[0065] Example 6

[0066] (1) MgO and Al2O3 were mixed in a molar ratio of 2:1, 7% wt CoO was added, and the mixture was fully ground in a ball mill. The particle size of the mixture after grinding was 600 mesh;

[0067] (2) ultrasonically treating the ground mixture for 20 minutes; placing the ultrasonicated material in a reactor and heating it at 200° C. for 24 hours to obtain a porous precursor;

[0068] (3) After the porous precursor is fully dried, 1 wt% of nano-LiF is added; all reactants are placed in an electric furnace, N2 protective gas is introduced, and the reaction is carried out at a high temperature of 700°C for 3 hours to obtain a calcined product;

[0069] (4) First, 8 wt% Pd nanoparticles and titanium dioxide nanotubes were mixed, and the reaction temperature was maintained at 850 ° C in a nitrogen atmosphere for 2 hours; then, 8 wt% loaded titanium dioxide nanotubes and the calcined product were mixed, and the reaction temperature was 40 ° C for 8 minutes. After the reaction was completed, it was allowed to stand at room temperature for 4 hours to obtain a light green refractory wall material.

[0070] Example 7

[0071] (1) MgO and Al2O3 were mixed in a molar ratio of 2:1, 15% wt CoO was added, and the mixture was fully ground in a ball mill. The particle size of the mixture after grinding was 600 mesh;

[0072] (2) ultrasonically treating the ground mixture for 20 minutes; placing the ultrasonicated material in a reactor and heating it at 200° C. for 24 hours to obtain a porous precursor;

[0073] (3) After the porous precursor is fully dried, 1 wt% of nano-LiF is added; all reactants are placed in an electric furnace, N2 protective gas is introduced, and the reaction is carried out at a high temperature of 800°C for 2 hours to obtain a calcined product;

[0074] (4) First, 8 wt% Pd nanoparticles and titanium dioxide nanotubes were mixed, and the reaction temperature was maintained at 850°C in a nitrogen atmosphere for 2 hours; then, 8 wt% loaded titanium dioxide nanotubes and the calcined product were mixed, and the reaction temperature was 40°C for 8 minutes. After the reaction was completed, the mixture was allowed to stand at room temperature for 4 hours to obtain a nearly black refractory wall material.

[0075] Comparative Example 1 (the difference from Example 1 is that the molar ratio of MgO to Al2O3 is 1:1)

[0076] (1) MgO and Al2O3 were mixed in a molar ratio of 1:1 and ground thoroughly in a ball mill until the mixture had a particle size of 600 mesh;

[0077] (2) ultrasonically treating the ground mixture for 20 minutes; placing the ultrasonicated material in a reactor and heating it at 200° C. for 24 hours to obtain a porous precursor;

[0078] (3) After the porous precursor is fully dried, 1 wt% of nano-LiF is added; all reactants are placed in an electric furnace, N2 protective gas is introduced, and the reaction is carried out at a high temperature of 700°C for 4 hours to obtain a calcined product;

[0079] (4) First, 5 wt% Pd nanoparticles and titanium dioxide nanotubes were mixed, and the reaction temperature was maintained at 800 ° C in a nitrogen atmosphere for 2 hours; then, 5 wt% loaded titanium dioxide nanotubes and the calcined product were mixed, and the reaction temperature was 50 ° C for 8 minutes. After the reaction was completed, the mixture was allowed to stand at room temperature for 2 hours to obtain a refractory wall material.

[0080] Comparative Example 2 (the difference from Example 1 is that nano-LiF is not added)

[0081] (1) MgO and Al2O3 were mixed in a molar ratio of 2:1 and ground thoroughly in a ball mill until the particle size of the mixture was 600 mesh;

[0082] (2) ultrasonically treating the ground mixture for 20 minutes; placing the ultrasonicated material in a reactor and heating it at 200° C. for 24 hours to obtain a porous precursor;

[0083] (3) After the porous precursor is fully dried, it is placed in an electric furnace, N2 protective gas is introduced, and the reaction is carried out at a high temperature of 700°C for 4 hours to obtain a calcined product.

[0084] Comparative Example 3 (the difference from Example 1 is that the amount of loaded titanium dioxide is low)

[0085] (1) MgO and Al2O3 were mixed in a molar ratio of 2:1 and ground thoroughly in a ball mill until the particle size of the mixture was 600 mesh;

[0086] (2) ultrasonically treating the ground mixture for 20 minutes; placing the ultrasonicated material in a reactor and heating it at 200° C. for 24 hours to obtain a porous precursor;

[0087] (3) After the porous precursor is fully dried, 1 wt% of nano-LiF is added; all reactants are placed in an electric furnace, N2 protective gas is introduced, and the reaction is carried out at a high temperature of 700°C for 4 hours to obtain a calcined product;

[0088] (4) First, 1 wt% Pd nanoparticles and titanium dioxide nanotubes were mixed, and the reaction temperature was maintained at 800°C in a nitrogen atmosphere for 2 hours; then, 1 wt% loaded titanium dioxide nanotubes and the calcined product were mixed, and the reaction temperature was 50°C for 8 minutes. After the reaction was completed, the mixture was allowed to stand at room temperature for 2 hours to obtain a refractory wall material.

[0089] Comparative Example 4 (the difference from Example 1 is that titanium dioxide is not loaded)

[0090] (1) MgO and Al2O3 were mixed in a molar ratio of 2:1 and ground thoroughly in a ball mill until the particle size of the mixture was 600 mesh;

[0091] (2) ultrasonically treating the ground mixture for 20 minutes; placing the ultrasonicated material in a reactor and heating it at 200° C. for 24 hours to obtain a porous precursor;

[0092] (3) After the porous precursor is fully dried, 1 wt% of nano-LiF is added; all reactants are placed in an electric furnace, N2 protective gas is introduced, and the reaction is carried out at a high temperature of 700°C for 4 hours to obtain a calcined product;

[0093] (4) First, 5 wt% of Pd nanoparticles and titanium dioxide nanotubes were mixed, and the reaction temperature was maintained at 600°C in a nitrogen atmosphere for 1 hour; then, 5 wt% of loaded titanium dioxide nanotubes and the calcined product were mixed, and the reaction temperature was 30°C for 5 minutes. After the reaction was completed, the mixture was allowed to stand at room temperature for 2 hours to obtain a refractory wall material.

[0094] Comparative Example 5 (the difference from Example 1 is that no porous precursor is formed and nano-LiF is directly added for calcination)

[0095] (1) MgO and Al2O3 were mixed in a molar ratio of 2:1 and ground thoroughly in a ball mill until the particle size of the mixture was 600 mesh;

[0096] (2) ultrasonically treating the ground mixture for 20 min;

[0097] (3) After being fully dried, 1 wt% of nano-LiF was added; all the reactants were placed in an electric furnace, N2 protective gas was introduced, and the reaction was carried out at a high temperature of 700°C for 4 hours to obtain a calcined product;

[0098] (4) First, 5 wt% Pd nanoparticles and titanium dioxide nanotubes were mixed, and the reaction temperature was maintained at 800 ° C in a nitrogen atmosphere for 2 hours; then, 5 wt% loaded titanium dioxide nanotubes and the calcined product were mixed, and the reaction temperature was 50 ° C for 8 minutes. After the reaction was completed, the mixture was allowed to stand at room temperature for 2 hours to obtain a refractory wall material.

[0099] Comparative Example 6 (the difference from Example 1 is that the calcination temperature is too high)

[0100] (1) MgO and Al2O3 were mixed in a molar ratio of 2:1 and ground thoroughly in a ball mill until the particle size of the mixture was 600 mesh;

[0101] (2) ultrasonically treating the ground mixture for 20 minutes; placing the ultrasonicated material in a reactor and heating it at 200° C. for 24 hours to obtain a porous precursor;

[0102] (3) After the porous precursor is fully dried, 1 wt% of nano-LiF is added; all reactants are placed in an electric furnace, N2 protective gas is introduced, and the reaction is carried out at a high temperature of 1500°C for 4 hours to obtain a calcined product;

[0103] (4) First, 5 wt% Pd nanoparticles and titanium dioxide nanotubes were mixed, and the reaction temperature was maintained at 800 ° C in a nitrogen atmosphere for 2 hours; then, 5 wt% loaded titanium dioxide nanotubes and the calcined product were mixed, and the reaction temperature was 50 ° C for 8 minutes. After the reaction was completed, the mixture was allowed to stand at room temperature for 2 hours to obtain a refractory wall material.

[0104] Comparative Example 7 (the difference from Example 1 is that the calcination temperature is too low)

[0105] (1) MgO and Al2O3 were mixed in a molar ratio of 2:1 and ground thoroughly in a ball mill until the particle size of the mixture was 600 mesh;

[0106] (2) ultrasonically treating the ground mixture for 20 minutes; placing the ultrasonicated material in a reactor and heating it at 200° C. for 24 hours to obtain a porous precursor;

[0107] (3) After the porous precursor is fully dried, 1 wt% of nano-LiF is added; all reactants are placed in an electric furnace, N2 protective gas is introduced, and the reaction is carried out at a high temperature of 500°C for 4 hours to obtain a calcined product;

[0108] (4) First, 5 wt% Pd nanoparticles and titanium dioxide nanotubes were mixed, and the reaction temperature was maintained at 800 ° C in a nitrogen atmosphere for 2 hours; then, 5 wt% loaded titanium dioxide nanotubes and the calcined product were mixed, and the reaction temperature was 50 ° C for 8 minutes. After the reaction was completed, the mixture was allowed to stand at room temperature for 2 hours to obtain a refractory wall material.

[0109] Table 1

[0110]

[0111]

[0112] As shown in Table 1, the yield of the refractory wall material obtained in Comparative Example 1 is not high. Comparative Example 2 did not obtain a refractory wall material under the same synthesis conditions. Comparative Example 3 had a low titanium dioxide loading, and the formaldehyde decomposition effect on the wall was tested using formaldehyde detection paper. It was found that the spinel refractory material had a poor formaldehyde decomposition effect. Comparative Example 4 failed to load titanium dioxide, resulting in poor formaldehyde decomposition performance. Comparative Example 5 failed to form a porous precursor, the catalytic effect of nano-LiF was poor, and the generated spinel refractory wall material had large voids and poor mechanical properties. Due to the high temperature in Comparative Example 6, the porosity increased to 40% during cooling, which did not meet the porosity of normal refractory materials, and the mechanical properties were too low. The temperature in Comparative Example 7 was too low, and the generated spinel refractory wall material had large voids and poor mechanical properties.

[0113] The above embodiments of the present invention are merely examples for illustrating the present invention and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations and modifications can be made based on the above description. It is not possible to enumerate all embodiments here. Any obvious variations or modifications arising from the technical solution of the present invention remain within the scope of protection of the present invention.

Claims

1. A method for preparing a fire-resistant wall material that can automatically decompose formaldehyde, characterized in that: The steps include: (1) MgO and Al2O3 were mixed in a molar ratio of 1.5-2.5:1, subjected to ball milling and ultrasonication, and then heated for reaction at a temperature of 180-240°C for 20-26 hours to obtain a porous precursor; (2) Mixing the porous precursor and nano-LiF, wherein the amount of nano-LiF added is 0.5-1.5% of the mass of the porous precursor, and calcining at 700-1100°C for 1-5 hours under nitrogen protection to obtain a calcined product; (3) 3-8 wt% Pd nanoparticles are loaded onto the surface of titanium dioxide nanotubes, and the reaction temperature is 700-900 ° C and maintained for 1.5-3 hours in a nitrogen atmosphere; then 3-8 wt% of the loaded titanium dioxide nanotubes are loaded onto the calcined product, and the reaction temperature is 40-60 ° C and the reaction time is 5-10 minutes. After the reaction is completed, the reaction is allowed to stand at room temperature for 2-5 hours to obtain a refractory wall material.

2. The method for preparing a fire-resistant wall material capable of automatically decomposing formaldehyde according to claim 1, wherein: The particle size after ball milling is 200-700 meshes.

3. The method for preparing a fire-resistant wall material capable of automatically decomposing formaldehyde according to claim 1, wherein: The ultrasonic time is 10-30 minutes.

4. The method for preparing a fire-resistant wall material capable of automatically decomposing formaldehyde according to claim 1, wherein: In step (1), while the MgO and Al2O3 are mixed, CoO is also added and mixed together.

5. The method for preparing a fire-resistant wall material capable of automatically decomposing formaldehyde according to claim 4, wherein: The amount of CoO added is 1-15% of the total mass of the mixture of MgO and Al2O3.

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