KR102024689B1 - Manufacturing method of buildingmaterials using silica gel - Google Patents

Abstract

The present invention provides a method for manufacturing building subsidiary materials using silica gel which can collect hygroscopic materials, which are then discarded after use, and be washed, dried, pulverized, calcined, and the like. The present invention (a) collecting the silica gel, then washing and drying; (b) grinding the dried silica gel to a uniform size; And (c) it provides a method for producing a building material using a silica gel comprising the step of manufacturing the building material by mixing the prepared silica gel.

Description

Manufacturing method of building materials using silica gel

The present invention relates to a method for manufacturing a building subsidiary material using silica gel, and then, the silica gel, which is disposed of after use, is collected, and then washed, dried, pulverized, calcined, and the like, to produce a hygroscopic material for construction or a non-hygroscopic material. It relates to a manufacturing method of the building subsidiary materials used.

Honeycomb structures in which moisture absorbents such as silica gel and zeolite are supported are widely used as dehumidifying elements. In comparison with silica gel and zeolite, in general, when the relative humidity is low, the zeolite side has a high moisture absorption amount, and when the relative humidity is high, the silica gel side has a high moisture absorption amount. Among the silica gels, the moisture absorption amount of the A-type silica gel is relatively high when the relative humidity is low. However, as the relative humidity increases, the moisture absorption amount reaches a limit, while the B-type silica gel generally has a moisture absorption amount of 90% or less. In the case of low and high relative humidity exceeding 90% relative humidity, a very high moisture absorption is shown.

Such silica gel is encapsulated in a porous package and used as a dehumidifying agent in various fields.

As an example, Korean Utility Model No. 463262 discloses a shoe silica gel dehumidifying agent having excellent dehumidification and deodorization efficiency by constructing an outer shell surrounding silica gel in two layers and confirming the hygroscopic state of the silica gel through a viewing window.

In the Republic of Korea Utility Model No. 388574, a piece of wrapping paper is folded in half to bond the edges, to form an accommodating space for accommodating silica gel therein, and to bond the surface film having a plurality of air holes formed on the outer surface of the wrapping paper. Disclosed is a silica gel dehumidifying wrapper coated with acrylic resin on its surface.

Korean Patent Laid-Open Publication No. 2006-0091612 discloses a shoe dehumidifying agent made of a mixture of charcoal and silica gel.

However, most of the silica gel used is disposed of as general waste, which is a concern for environmental pollution by silica gel. In particular, silica gel does not decompose naturally, and has a porosity, so that it can adsorb contaminants and toxic substances and then release them slowly. Thus, silica gel can act as a carrier for transporting contaminants or toxic substances, causing the spread of contamination. Therefore, although a technique for regenerating and recycling used silica gel has been developed, its use is very limited.

SUMMARY OF THE INVENTION An object of the present invention is to collect a silica gel which is discarded after use, and then, through washing, drying, grinding, and firing steps, to provide a method for manufacturing a building subsidiary material using silica gel capable of producing a building hygroscopic material or a nonhygroscopic material. It is.

In order to solve the above problems, the present invention comprises the steps of (a) collecting the silica gel, then washing and drying; (b) grinding the dried silica gel to a uniform size; And (c) it provides a method for producing a building material using a silica gel comprising the step of manufacturing the building material by mixing the prepared silica gel.

After step (b); (b`) calcining the pulverized silica gel; And (b``) cooling the calcined silica gel.

The drying of step (a) may be carried out at a temperature of 20 ~ 200 ℃.

The grinding of step (b) may be performed using a rolling mill, a roller mill, or a grinder so that the particle size of the silica gel is 5 to 600 mesh.

The firing may be calcined for 30 minutes to 168 hours at a temperature of 200 ~ 1,800 ℃ pulverized particles.

The building material may be a hygroscopic wallpaper, a hygroscopic brick or a hygroscopic block.

The building material may be a refractory brick or refractory cement.

The firebrick or refractory cement manufacturing method; (i) mixing hydrates with water to form at least two compounds selected from the group consisting of mild magnesia, magnesium hydroxide, silica, aluminum hydroxide and calcium hydroxide; (ii) adding and mixing 10 to 30 parts by weight of the hydrate, 80 to 120 parts by weight of olivine and 0.1 to 1 part by weight of hydrofluoric acid based on 100 parts by weight of dead burned magnesia (DBM); And (iii) calcining the mixture at 500 to 1800 ° C. to produce a magnesia-silica gel clinker.

The manufacturing method comprises the steps of grinding the magnesia-silica gel clinker; 25-40% by weight of expanded vermiculite, 5-10% by weight of unexpanded vermiculite, 3-10% by weight of magnesia-silica gel clinker powder, 5-10% by weight of IR opaque agent, 20-50% by weight of sodium silicate And a mixing step of mixing 10 to 12% by weight of fast cement. A molding step of thermally pressing the mixture obtained in the mixing step for 1 to 3 minutes at a temperature of 100 to 350 ° C. and a pressure of 250 to 350 kgf / m 2; And it may further comprise a drying step of naturally drying the molding obtained in the molding step for 24 to 48 hours.

The method for manufacturing building materials using silica gel according to the present invention can produce a building material having flame retardancy or hygroscopicity at a low price as well as spreading pollutants by collecting silica gel to be discarded and using it for building subsidiary materials through a simple process. Since the porous silica gel can be recycled and used, it is possible to minimize the diffusion of contaminants.

1 briefly illustrates a building material production process according to an embodiment of the present invention.

Hereinafter, a preferred embodiment of the present invention will be described in detail. In the following description of the present invention, if it is determined that the detailed description of the related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted. Throughout the specification, when a part is said to "include" a certain component, it means that it may further include other components, not to exclude other components, unless otherwise stated.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all transformations, equivalents, and substitutes included in the spirit and scope of the present invention.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present invention, the terms including or having are intended to indicate that there is a feature, number, step, operation, component, part, or a combination thereof described in the specification, but one or more other features or numbers, step It is to be understood that the present invention does not exclude in advance the possibility of the presence or the addition of an operation, a component, a part, or a combination thereof.

The present invention comprises the steps of (a) collecting the silica gel, followed by washing and drying; (b) grinding the dried silica gel to a uniform size; And (c) relates to a method of manufacturing a building material using a silica gel comprising the step of manufacturing the building material by mixing the prepared silica gel.

The step (a) is to remove the contaminants adsorbed on or inside the surface of the collected silica gel, the silica gel may be used in a semiconductor factory, hospital, etc., or may be used as a desiccant for food, medicine, silicon and the like. In addition, the silica gel may be used in various types (A, B, C), but can be used regardless of the type.

In addition, the drying of step (a) may be carried out at a temperature of 20 ~ 200 ℃. If it is dried below 20 ℃, the adsorbed foreign matters are not removed, so when used as building materials, the release of contaminants may be a problem.If it is dried above 200 ℃, the effect of removing foreign substances is the same, but the amount of heat used is high. Additional costs may be required for manufacturing.

The step (b) is to pulverize the dried silica gel to have a uniform size, and may be performed using a rolling mill, a roller mill, or a grinder so that the particle size of the silica gel becomes 5 to 600 mesh. have. If the particle size of the silica gel is less than 5 mash, the silica gel particles may be broken after the building material is manufactured, and the physical properties of the building material may be degraded. If the size of the silica gel is larger than 600 mash, cohesion may occur when mixed with other materials.

After step (b); (b`) calcining the pulverized silica gel; And (b``) cooling the calcined silica gel. Silica gel has a porosity and can adsorb various materials. However, in the case of fireproof building materials, since the fire resistance may be reduced when manufactured using a porous material, it is preferable to reduce the size of the pores through the firing step of (b`) and (b``). At this time, the firing is preferably baked for 30 minutes to 168 hours at a temperature of 200 ~ 1,800 ℃ pulverized particles. When firing for less than 200 ℃ or less than 30 minutes, large pores remain, which may lower fire resistance. If firing over 1,800 ℃ or more than 168 hours, the effect of firing is the same but additional cost is required. Can be.

The building material may be a hygroscopic wallpaper, a hygroscopic brick or a hygroscopic block, and may be a firebrick or a fireproof cement. When used in building materials without firing the silica gel as described above it is possible to manufacture the hygroscopic material by the porosity of the silica gel, it is possible to produce a refractory material when manufactured through the firing process. At this time, the hygroscopic material may be a hygroscopic brick or a hygroscopic block, and the fire resistant material may be a fire brick or a fire cement.

The firebrick or refractory cement manufacturing method; (i) mixing hydrates with water to form at least two compounds selected from the group consisting of mild magnesia, magnesium hydroxide, silica, aluminum hydroxide and calcium hydroxide; (ii) adding and mixing 10 to 30 parts by weight of the hydrate, 80 to 120 parts by weight of olivine and 0.1 to 1 part by weight of hydrofluoric acid based on 100 parts by weight of dead burned magnesia (DBM); And (iii) calcining the mixture at 1500 to 1800 ° C. to produce a magnesia-silica gel clinker.

In the present invention, in general, clinker (clinker), in particular, magnesia clinker is a mass produced by baking magnesite, magnesium hydroxide and the like at a high temperature of 1500 ℃ or more are widely used as interior materials of refractory bricks, cement kilns, basic steelmaking furnaces.

In general, magnesia clinker is mainly used as a lining material for steelmaking, but the chemical composition of the conventional magnesia clinker is 75% MgO, which is suitable for high base composition, but the magnesia-silica system containing a large amount of silica component The chemical composition of the clinker is preferably suitable for the composition of the low base, with the MgO content of 50 to 75% of the total weight of the clinker, and is used for not only brick manufacturing but also electric spraying and tundish coating materials. Can be.

Magnesia-silica-based (MgO Rich-SiO ₂ ) clinker comprising 20 to 50 parts by weight of silica (SiO ₂ ) and 5 to 9 parts by weight of iron oxide (Fe ₂ O ₃ ), based on 100 parts by weight of magnesia (MgO). It is about.

In the clinker composition, when the silica is 50 parts by weight or more, the compound in the matrix may cause excessive corrosion, resulting in deterioration of corrosion resistance due to lowering the degree of fire resistance, and when the silica is 20 parts by weight or less, MgO / SiO ₂ in the clinker is Mg ( Due to a slaking phenomenon caused by a hydration reaction converted to OH) ₂ , there are problems that it is difficult to store for a long time and deterioration in corrosion resistance. Preferably, the MgO / SiO ₂ ratio may be 9-6: 1-4.

In the clinker composition, when iron oxide (Fe ₂ O ₃ ) is out of the range of 5 to 9 parts by weight, there is a problem that the corrosion resistance is lowered.

In the present invention, the clinker may further contain 2 to 6 parts by weight of aluminum oxide (Al ₂ O ₃ ), 2 to 6 parts by weight of calcium oxide (CaO ₂ ) and 0.02 to 2 parts by weight of potassium oxide.

In the present invention, olivine (olivine) is a coarse mineral belonging to a tetragonal system and forms columnar crystals, but crystals are not clear. Olive or yellowish brown to grayish red, transparent or translucent, streak color white, firmness 6.5 ~ 7, specific gravity 3.2 ~ 3.4. Most of these olivines have been used as a source of magnesia (MgO) in steelmaking processes, or as soluble phosphate fertilizers as industrial raw materials.

In addition, the hydrate may be characterized in that a mixture of two or more selected from the group consisting of light magnesium, magnesium hydroxide, ultra-fine silica, aluminum hydroxide and calcium hydroxide, which, when forming the MgO Rich-SiO ₂ system clinker , 10-30 parts by weight of light magnesia, magnesium hydroxide, ultrafine silica, aluminum hydroxide and calcium hydroxide, with respect to the overall composition of the clinker, to form a known stable compound and to form coarse crystal magnesia in the clinker and to improve the infiltration resistance. 2 or more types are mixed with water, and uniform mixing is performed using a ball mill or an attention mill.

In the present invention, the olivine is contained in an amount of 80 to 120 parts by weight in the total content of the clinker, at this time, if contained less than 80 parts by weight, there is a problem of lowering the corrosion resistance, if contained in more than 120 parts by weight is economical There is no problem.

In the present invention, the hydrate is contained in 10 to 30 parts by weight of the total content of the clinker, at this time, if contained less than 10 parts by weight, there is a problem that the corrosion resistance is lowered, if contained in more than 30 parts by weight is not economical in terms of cost there is a problem.

In the present invention, in order to form a homogeneous mixing and stable compound, hydrofluoric acid is added as a reaction aid of silica, and the amount of hydrofluoric acid is preferably contained in an amount of 0.1 to 1.0 parts by weight based on the total amount of clinker. At this time, if the hydrofluoric acid is contained in less than 0.1 parts by weight, there is a problem that the uniform mixing is not made, if it exceeds 1 part by weight there is no gain due to the excess content.

The firing of the step (iii) in the present invention may be performed by maintaining about 72hrs at a temperature of about 1,500 ~ 1,800 ℃ using Shaft Kiln.

In the present invention, during the production of the refractory brick, it may contain additional other components in the magnesia-silica-based clinker, for example, by refractory by adding 10 to 30 parts by weight of carbonaceous material to 100 parts by weight of the magnesia-silica-based clinker Bricks may be prepared, in which carbon water is contained in an amount of less than 10 parts by weight, resulting in problems of corrosion resistance and spalling properties due to a decrease in wetting resistance, and a problem of high temperature strength due to oxidation of a product in excess of 30 parts by weight.

In the present invention, when manufacturing the refractory brick, magnesia-silica-based clinker is selected from the group consisting of molten magnesia natural fusedmagnesia (FMM), small and small magnesia DBM (Dead Burned Magnesia) and sintered magnesia SM (Sintered Magnesia) The firebrick can be manufactured by adding 10 to 100 parts by weight of any one. In this case, when NFM, DBM, and SM deviate from the weight range, there is a problem in that it is not economical in terms of cost and corrosion resistance is lowered.

The NFM (Natural Fused Magnesia) is the melting and coagulation of magnesite is developed as a complete magnesia (Periclase, MgO) crystals, it is most common to calculate the magnesium carbonate as a main component magnesite in natural state, but natural magnesite is high temperature The treatment is converted to magnesia, and the NFM generally has a composition of 96.5% MgO, 1.25% CaO, 1.2% SiO, 0.1% Al ₂ O ₃ , and 0.95% Fe ₂ O ₃ .

In the present invention, DBM is to remove magnesium carbonate by heating magnesium carbonate to a high temperature of 1500 ~ 1600 ℃, MgO content is 90 ~ 97%, SM is molded by pressing the magnesium carbonate into a suitable shape and heated to a high temperature of 1700 ℃ or more To make a curable material, MgO content is 93 ~ 98%. In addition, it may further contain components known to be included in the conventional DBM, SM. In the prior art, the DBM, SM, and NFM can be easily obtained, and examples thereof include commercially available products from Samwha Corporation.

In addition, the building material manufacturing method comprises the steps of grinding the magnesia-silica gel clinker; 25-40% by weight of expanded vermiculite, 5-10% by weight of unexpanded vermiculite, 3-10% by weight of magnesia-silica gel clinker powder, 5-10% by weight of IR opaque agent, 20-50% by weight of sodium silicate And a mixing step of mixing 10 to 12% by weight of fast cement. A molding step of thermally pressing the mixture obtained in the mixing step for 1 to 3 minutes at a temperature of 100 to 350 ° C. and a pressure of 250 to 350 kg _f / m 2; And it may further comprise a drying step of naturally drying the molding obtained in the molding step for 24 to 48 hours.

The raw materials used in the above mixing step may be mixed in random order, but for complete mixing, first, the expanded vermiculite and the unexpanded vermiculite are mixed to obtain a vermiculite mixture, and magnesia-silica gel clinker powder and IR opaque agent To obtain a magnesia-silica gel clinker powder and an IR opacifier mixture, and to mix a sodium silicate and a fast cement to obtain a sodium silicate and a fast cement mixture, followed by a vermiculite mixture and a magnesia-silica gel clinker powder and an IR opaque mixture. It is desirable to mix the mixture and the sodium silicate and the fast cement mixture.

That is, the mixing of the expanded vermiculite and the unexpanded vermiculite is to distribute the unexpanded vermiculite particles evenly among the expanded vermiculite particles so that the expansion of the unexpanded vermiculite by the fire is made evenly.

In general, vermiculite discolors to silver or ocher color when heated in the range of 200 ~ 800 ℃ in the reducing blast furnace, and the volume expands to more than 12 times the original particle.

Therefore, the expanded particles have a myriad of pores are formed to have a high air permeability and low thermal conductivity, it is possible to exhibit excellent functions in thermal insulation, non-combustibility and fire resistance.

In addition, the unexpanded vermiculite is located between the expanded particles by utilizing the property of expansion above 200 ℃ to expand due to high heat in the case of fire acts to seal the voids between the expanded particles, so the airtightness as a non-combustible fireproof insulation It also increases the heat shielding and flame retardant effect.

In addition, the mixing of the magnesia-silica gel clinker powder and the IR opaque agent is to distribute evenly between the expanded vermiculite while the magnesia-silica gel clinker powder and the IR opaque agent are sufficiently mixed, wherein the magnesia-silica gel clinker powder is a high purity silicon compound. As the basic particles are small, spherical and have a large surface area, the average diameter of the spherical basic particles has a size of 5 ~ 50㎜, the specific surface area is in the form of a powder in the range of 40 ~ 400㎡ / g. However, by firing the existing porous silica gel to reduce the size of the pores, the specific surface area is smaller than the general silica gel (500 ~ 700㎡ / g).

The magnesia-silica gel clinker powder is evenly distributed between the expanded vermiculite particles. In general, insulators containing internal air form heat conduction by particles and heat transfer due to convection of air between the particles.

Therefore, the magnesia-silica gel clinker powder is located between the expanded vermiculite particles, which weakens the convection of air and deforms the heat transfer path, thereby reducing the apparent thermal conductivity.

In addition, the IR opaque agent is composed of carbon black, titanium dioxide, nitrous oxide and zirconium dioxide, which serves to reduce the radiant heat by scattering the radiant heat between the expanded vermiculite particles.

Therefore, the magnesia-silica gel clinker powder and the IR opaque agent reduce heat transfer (convection, radiation) generated in the pores between the expanded vermiculite particles, thereby improving the thermal insulation effect as a nonflammable refractory insulating material.

In addition, the mixture of sodium silicate and fast cement is to obtain an inorganic binder, which is cured by the following reaction.

_{Na 2 O · SiO 2 · nH} 2 O + 2CaO · SiO 2 → 8CaO · SiO 2 · nH 2 O + SiO + NaOH

Therefore, sodium silicate and dicalcium silicate react by chemical reaction of its own components even without heat from the outside, thereby curing at room temperature.

In the present invention, as a fast cement, a fast cement containing mainly limestone silicate is used, but a fast cement containing tricalcium silicate may be used.

Meanwhile, the molding step of thermopressing the mixture obtained through the mixing step with a heated molding machine is thermally pressurized for 1 to 3 minutes at a pressure of 250 to 350 kg _f / m 2 through a molding machine to which heat of 100 to 350 ° C. is applied.

And the drying step of drying the press-molded molding through the forming step is to naturally dry for 24 to 48 hours to obtain a finished refractory brick, during this natural drying, due to the fast-drying cement contained in the mixture It can be done.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. In addition, in describing the present invention, when it is determined that a detailed description of a related known function or known configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. And certain features shown in the drawings are enlarged or reduced or simplified for ease of description, the drawings and their components are not necessarily drawn to scale. However, those skilled in the art will readily understand these details.

Example

10 kg of silica gel collected at a hospital near Seoul was washed with water, and then dried at a temperature of 150 ° C. for 12 hours. Thereafter, the particles were ground to an average size of 200 mesh using a rolling mill, and then calcined and cooled in a baking furnace at 250 ° C. for 1 hour to obtain silica gel powder.

In order to prepare the magnesia-silica gel clinker according to the present invention, 100 parts by weight of DBM (dead burned magnesia), 5 parts by weight of mild magnesium 5 parts by weight of magnesium hydroxide 5 parts by weight of the silica gel powder and 20 parts by weight of a hydrate composed of residue water, natural minerals 100 parts by weight of olivine and 0.5 part by weight of hydrofluoric acid were added and mixed, and the mixture was filtered, dried at room temperature for 72 hours, pelletized, and calcined at 1500 ° C. using Shaft Kiln for 72 hours. Silica-based clinker was prepared.

Thereafter, the prepared magnesia-silica gel clinker was pulverized to prepare a firebrick, and then 30% by weight of expanded vermiculite, 7% by weight of unexpanded vermiculite, 7% by weight of magnesia-silica gel clinker powder, and an IR opaque agent. 7% by weight of carbon black, 35% by weight of sodium silicate, and 11% by weight of fast cement containing dicalcium silicate were mixed, and the mixture was thermally press-molded at a temperature of 250 ° C. and a pressure of 300 kgf / m 2 for 2 minutes. . The molded product obtained in the molding step was naturally dried for 30 hours to prepare a firebrick. As Comparative Example 1, the same experiment was performed using a conventional refractory brick, NFM brick. As Comparative Example 2, an NFM brick including 7% by weight of the magnesia-silica gel clinker was prepared and tested.

division Comparative Example 1 Comparative Example 2 Example Physical properties Room temperature importance 2.90 2.81 1.51 Volume specific gravity 3.02 2.91 1.48 Porosity (%) 4.12 4.20 8.15 Compressive strength (MPa) 43 52 41 Bending strength (MPa) 20.5 21.0 19.8 High temperature Volume specific gravity 2.92 2.84 1.31 Porosity (%) 14.11 13.10 18.4 Compressive strength (MPa) 26 41 48 Bending strength (MPa) 0.2 9.8 7.8 Residual Line Change (%) +0.31 +0.58 +1.51

As shown in Table 1, the strength was about 5% lower than that of the conventional firebrick, but the weight was lower due to the lower specific gravity. In addition, as shown in the high temperature experiment, the vermiculite is partially expanded at high temperature, and the porosity is increased, which indicates that the thermal barrier performance is further increased when exposed to high temperature.

As described above in detail specific parts of the present invention, it will be apparent to those skilled in the art that these specific descriptions are merely preferred embodiments, and thus the scope of the present invention is not limited thereto. will be. Thus, the substantial scope of the present invention will be defined by the appended claims and their equivalents.

Claims (9)

(a) collecting silica gel, followed by washing and drying;
(b) grinding the dried silica gel to a uniform size; And
(c) preparing a building material by mixing the prepared silica gel;
In the manufacturing method of building materials using a silica gel comprising a,
After step (b);
(b`) calcining the pulverized silica gel; And
(b``) cooling the calcined silica gel;
Additionally contains
The building material is a refractory brick or refractory cement,
The firebrick or refractory cement manufacturing method;
(i) mixing hydrates with water to form at least two compounds selected from the group consisting of light magnesium, magnesium hydroxide, silica, aluminum hydroxide and calcium hydroxide;
(ii) adding and mixing 10 to 30 parts by weight of the hydrate, 80 to 120 parts by weight of olivine and 0.1 to 1 part by weight of hydrofluoric acid based on 100 parts by weight of dead burned magnesia (DBM); And
(iii) calcining the mixture at 1500-1800 ° C. to produce a magnesia-silica gel clinker,
Grinding the magnesia-silica gel clinker;
25-40% by weight of expanded vermiculite, 5-10% by weight of unexpanded vermiculite, 3-10% by weight of magnesia-silica gel clinker powder, 5-10% by weight of IR opacifier, and 20-50% by weight of silicate And a mixing step of mixing 10 to 12% by weight of fast cement.
A molding step of thermally pressing the mixture obtained in the mixing step for 1 to 3 minutes at a temperature of 100 to 350 ° C. and a pressure of 250 to 350 kgf / m 2; And
Method of manufacturing building materials using silica gel further comprising a; drying step of naturally drying the molding obtained in the molding step for 24 to 48 hours.
delete The method of claim 1,
The drying of step (a) is a manufacturing method of building materials using silica gel, characterized in that carried out at a temperature of 20 ~ 200 ℃.
The method of claim 1,
The grinding of step (b) is a method of manufacturing building materials using silica gel, characterized in that performed using a rolling mill, a roller mill, or a pulverizer so that the particle size of the silica gel is 5 to 600 mesh.
The method of claim 1,
The firing is a method of manufacturing a building material using a silica gel, characterized in that the pulverized particles are baked for 30 minutes to 168 hours at a temperature of 200 ~ 1,800 ℃.
The method of claim 1,
The building material is a hygroscopic wallpaper, a hygroscopic brick or a hygroscopic block, characterized in that the manufacturing method of building materials using silica gel.
delete delete delete

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