KR101893991B1 - Process for forming granular foam glass and method for manufacturing a photocatalyst for removing odor - Google Patents

Abstract

The present invention relates to a method of manufacturing a waste glass, comprising the steps of preparing waste glass in the form of powder, mixing the waste glass in the form of powder with a binder to form a granular shaped body, and firing and foaming the granular shaped body Preparing a granular foamed glass; And coating the granular foamed glass with titanium dioxide. The present invention also provides a method of manufacturing a photocatalyst.

Description

TECHNICAL FIELD The present invention relates to a process for forming a granular foam glass and a photocatalyst for removing odor using the same,

The present invention relates to a photocatalyst for removing odors, and more particularly, to a method for forming granular foam glass using waste glass as a raw material and a photocatalyst for removing odors using the same.

However, in the case of an air purifier, which is a deodorizing device applied to household or small-sized appliances, the object of the present invention is that the object of the present invention is that the odor- The purpose of this study is to maintain the basic indoor air quality rather than direct removal of odor, which is mainly used by adsorbing adsorbents such as activated carbon.

In the case of household deodorizing filters, air purifiers are being developed using HEPA filters as dust and fine dusts are becoming more common. In addition, a complex air purifying filter has been developed. However, in the case of a filter targeting household food waste, The most suitable device for treating high concentration of odor has not yet been proven.

In order to solve the above-mentioned problems, the present invention has been made to solve the problems of the prior arts, and it is an object of the present invention to provide a method for manufacturing a glass composition, which does not require melting, hydrolysis, The present invention also provides a method for producing a granular foamed glass having an effective function having a pore distribution and a photocatalyst for removing odors using the same. However, these problems are exemplary and do not limit the scope of the present invention.

There is provided a method for forming a granular foamed glass according to an aspect of the present invention and a method for producing a photocatalyst by coating nano-sized titanium dioxide.

The method for forming the granular foamed glass comprises the steps of: preparing waste glass in powder form; Mixing the powdery waste glass with a binder and a solvent to obtain a kneaded product for an extrusion molded product; Extruding the kneaded material into a desired shape to obtain a formed body; And firing the granular shaped extrudate to foam. Further, the method for producing the photocatalyst may include coating nano-sized titanium dioxide (TiO ₂ ) on the prepared granular foam glass; Heat treating the coated foamed glass.

In the method for forming a granular foamed glass, preparing the waste glass in powder form comprises: pulverizing the waste glass; And milling the waste glass.

In the method of forming the granular foamed glass, the binder may include methylcellulose or polyvinyl alcohol. In this case, the waste glass in powder form may be mixed with a binder and a solvent, The step of obtaining the kneaded material for a molded body may be characterized in that the content of the binder in the kneaded material is 1 to 5 wt%. On the other hand, the amount of the solvent to be added is preferably 10 wt% to 60 wt%, more preferably 25 wt% to 45 wt%.

In the method of forming the foamed glass, the step of firing and blowing the granular waste glass may include firing the granular waste glass at 800 to 1100 ° C for 1 to 4 hours.

In the step of coating the nano-sized titanium dioxide, obtaining a dispersion of the titanium dioxide in a well-dispersed liquid form using a solvent and a dispersant to form a uniform coating may be included.

In the step of coating the titanium dioxide, a step of immersing the foamed glass in the form of granules in a prepared titanium dioxide dispersion may be coated. After the foamed glass is immersed in the dispersion, the surface and pores of the granular foamed glass are ultrasonicated so as to smoothly discharge the air of the surface and the pores so that the dispersion can sufficiently penetrate into the surface and pores.

Removing the wire mesh to obtain a granular foam glass coated with the dispersion, and drying the foamed glass coated with the dispersion at 50 to 80 DEG C for 1 to 4 hours.

And firing the titanium dioxide at 400 to 700 ° C for 1 to 4 hours to fix the titanium dioxide coated on the granular foam glass to the surface of the foamed glass in the step of coating the titanium dioxide.

According to one embodiment of the present invention, since the foamed glass is manufactured through the process control without adding the foaming agent by using waste glass to be disposed of, the process is simplified and the process control is easy, and the aesthetic characteristic with uniform pore structure Excellent foamed glass can be produced, and thus photocatalysts of various shapes and sizes can be manufactured. Of course, the scope of the present invention is not limited by these effects.

1 is a flowchart showing a method of forming granular foam glass and a method of manufacturing a photocatalyst according to an embodiment of the present invention.
2 is an extrusion molding machine for molding a kneaded material for an extrusion molded article according to an embodiment of the present invention.
3 is a photograph (left) and a partial enlarged photograph (right) of the extruded product obtained by molding and drying the kneaded product using the extrusion molding machine.
Fig. 4 is a photograph of a sample (a) obtained by cutting the extrudate into granules and a sample (b) obtained by firing the same.
FIG. 5 is a graph showing pore characteristics of a granulated foamed glass according to an embodiment of the present invention in which granulated form extrudate is fired and foamed.
FIG. 6 is a SEM photograph of a granulated foamed glass obtained by firing and extruding a granular shaped extrudate according to an embodiment of the present invention.
7 is a photograph of a granulated sample (a), a coated granular foamed glass sample (b), and a titanium dioxide coated photocatalyst (c) according to an embodiment of the present invention.
8 is a schematic view of a module for evaluating the malodor removal efficiency.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, Is provided to fully inform the user. Also, for convenience of explanation, the components may be exaggerated or reduced in size.

Foamed glass is lightweight and exhibits excellent performance in flame blocking, heat insulation, heat resistance and sound absorption, and is used when industrial equipment waterproofing, heat resistance and durability are required. Especially, it is used as excellent thermal insulation material and sound absorbing material in structures and buildings.

As an example of the manufacturing principle of the foamed glass, a glass of a special composition is mixed together with a reducing agent such as carbon and a bubble forming agent containing an oxide, sulfate or other types of oxidizing components, followed by pulverizing the blended mixture Can be put into a certain container or frame and fired until softening or melting.

During this heat treatment process, a redox reaction takes place between the carbon and the sulfur oxides (or oxidants or oxides of the glass), so that the molten glass contains SO ₂ , CO ₂ , N ₂ , H ₂ S or other gases, It creates a material that is low density and forms a structure that is resistant to thermal conduction and radiation and forms pores in the glass. As a result, if the best results are obtained, the structure of the glass will have airtight pores that are immiscible with water or water vapor, or other liquids and gases.

Various methods are available for the manufacturing process of the foamed glass block manufactured according to such a manufacturing principle.

As a comparative example of the present invention, raw glass for producing foamed glass having a special composition can be produced primarily for producing foamed glass. To this end, various components such as Na ₂ SO ₄ , CaCO ₃ , MgCO ₃ , Na ₂ O, and As ₂ O ₃ are added to the raw material components for producing glass in order to be foamed glass, It is possible to make raw glass for manufacturing foamed glass which can make glass. Then, the thus-produced glass is pulverized and reacted with the other components to add a carbon component, which is a foaming agent for producing a gas acting as a direct blowing agent, and the mixture is mixed well. Then, the raw glass powder for manufacturing the mixed foamed glass is placed in a certain container The preform is heated at a temperature of 400 to 650 ° C and subjected to a foaming process at a temperature of 800 to 900 ° C, followed by a heat treatment such as cooling or slow cooling for stabilization. However, since this process requires a large amount of energy at a temperature of 1300 to 1600 캜 during melting as described above in the course of producing raw glass for manufacturing foamed glass, and thus, facility investment and management costs are required, The production cost of raw glass accounts for more than half of the production cost of foamed glass. On the other hand, in the production of foamed glass, it is very important to predict the foaming section of the glass as accurately as possible and to manufacture it at a low temperature. However, the principle of the generation of foamed glass is not known. Experiments for accurate prediction of foamed glass sections can be performed at a macroscopic level through real-time images using a high-temperature microscope, but it is impossible to predict the precise foaming interval of the glass, and only the unit is measured in millimeters (mm) There is a limit that can not be done.

The present invention is characterized in that foamed glass is produced by directly foaming waste glass without using any special pretreatment process for the production of foamed glass using waste glass produced in life or industry in general.

FIG. 1 is a flowchart showing steps of forming a granular foamed glass according to an embodiment of the present invention. Fig. 2 is an extrusion molding machine for molding a kneaded material for an extrusion molded product according to an embodiment of the present invention. Fig. 3 is a photograph (left) and a partial enlarged view of the extruded material ), And FIG. 4 is a photograph of a sample (a) obtained by cutting the extrudate into granules and a sample (b) obtained by firing the same.

1 and 4, a method of forming a granulated glass according to an embodiment of the present invention and a method of manufacturing a photocatalyst using the same will be described below.

First, waste glass is prepared as a foamed glass raw material (S10). The waste glass does not necessarily need to be in pulverized form. For example, the waste glass referred to in step S10 may be waste glass before being crushed. The waste glass includes, for example, waste glass of sodium-silicate or boroalumino-silicate composition. When such sodium-silicate or boroaluminosilicate composition waste glass is used as a raw material for the foamed glass, it is possible to manufacture the foamed glass without addition of an additional foaming agent.

Next, the prepared waste glass is pulverized and milled to produce a raw material powder for foaming (S20, S30). The prepared waste glass is pulverized by a wet pulverizing process using a pulverizing apparatus such as a disk mill or a ball mill. At this time, at least one solvent selected from the group consisting of water, ethyl alcohol, methyl alcohol and acetone can be used as the solvent.

The pulverization of the waste glass for efficient pulverization can be carried out through a plurality of steps. For example, the waste glass can be first pulverized by a dry method such as a jaw crusher or a disk mill, and then finely pulverized into a finer powder by a wet pulverizing process using a grinder such as a ball mill or a bead mill.

The finer particle size of the pulverized powder is preferably as small as possible, but the size of the powder may be adjusted to be 1 to 10 탆 in consideration of the economical cost of the powder.

Thereafter, a fine waste glass powder is obtained by using a drying device such as an oven (S40), and the binder and the solvent are mixed with each other to obtain a kneaded product for the extrusion molded product (S50). The binder may include methyl cellulose or polyvinyl alcohol, and preferably the content of the binder is 1 to 5 wt%. On the other hand, the amount of the solvent to be added is preferably 10 wt% to 60 wt%, more preferably 25 wt% to 45 wt%.

The kneaded material for extruded body is subjected to extrusion molding using an extrusion molding machine (see Fig. 2) to obtain an extrudate having a desired shape and size (see Fig. 3), and the extrudate is dried (S60). In one embodiment of the present invention, an extrusion molding mold capable of producing an elongated cylindrical shape was selected and an extrusion process was performed. Drying of the extrudate can be carried out by heating and drying using an electric oven or the like and natural drying by allowing to stand in the air. In the present embodiment, natural drying is carried out. Although there is an advantage of shortening the production time when heating and drying are carried out, there is a possibility that the surface is cracked due to rapid evaporation of the solvent due to heating and drying. However, when the kneaded material for extrusion molding is further prepared, Can be overcome by adjusting it closely. The dried extrudate was cut to a suitable length to obtain a granulated shaped body to obtain a dried molded body (see Fig. 4 (a)). For the automated process, extruded granules can be obtained by a continuous process by rotating and cutting the extruder with a cutter attached to the extruded portion of the extruder. By adjusting the diameter of the mold and the speed of the rotary cutter during extrusion molding, the diameter and length of the granules can be obtained in a desired form.

Subsequently, the granular shaped extrudate can be calcined at 800 to 1100 占 폚 for 1 to 4 hours (S70, see Fig. 4 (b)).

5 is a graph showing the characteristics of the granular foam glass in which the granular extrudate is fired and foamed (S70) in the method of forming granular foam glass according to an embodiment of the present invention.

Referring to FIG. 5, the average density of the granular foamed glass subjected to the step S70 in the embodiment of the present invention is 0.7122 g / cm 3, and the porosity thereof is 71.4%.

6 (a) and 6 (b) are electron micrographs taken at low magnification and high magnification, respectively, of the granular foamed glass subjected to the step of firing and expanding the granular extrudate according to an embodiment of the present invention. Referring to FIG. 6, it can be confirmed that pores exist in the granulated foamed glass in which the granulated extrudate is fired and foamed (S70).

In the present invention, the generation mechanism of the foamed glass will be described with reference to the following chemical formula 1.

As shown in Chemical Formula (1), when M in the formula (1) is Na as in the case of raw glass having a specific composition, for example, sodium silicate, when water is added, H + ions in the water and Na + And an NaOH alkali solution is formed (1 step). Next, the OH - ions of the NaOH alkali solution penetrate into the glass and destroy the SiO2 mesh structure (2Step). The glassy moisture or OH-component contained in the glass is decomposed as a result of hydrolysis to form bubbles in the softened or melted glass particles, and thus, Bubbles are formed in the resultant glass to form a foamed glass.

The foamed glass produced by the manufacturing process according to the embodiment of the present invention has a uniform micropore structure and can have excellent aesthetics as well as excellent mechanical properties. As an example, the physical properties of the foamed glass produced by the above process can exhibit a density value of 287 kg / m 3, a porosity of 88%, a compressive strength of 1.4 MPa and a thermal conductivity of 0.070 kcal / mh ° C at 25 ° C .

On the other hand, for the uniform coating of nano-sized titanium dioxide, a liquid dispersion in which titanium dioxide is well dispersed is prepared by using a solvent and a dispersant. The solvent may be at least one selected from the group consisting of water, ethyl alcohol, methyl alcohol and acetone. On the other hand, the addition amount of titanium dioxide in the titanium dioxide dispersion is preferably 1 wt% to 10 wt%, particularly 3 wt% to 5 wt%. The titanium dioxide, the solvent and the dispersant are mixed and stirred to obtain a titanium dioxide dispersion.

When the granular foamed glass is immersed in the dispersion, it is difficult to uniformly float on the dispersion due to the low density of the foamed glass. Therefore, it is wrapped in a certain volume using a wire mesh or the like and then immersed in the dispersion sufficiently. After the foamed glass is immersed in the dispersion, the surface of the granular foamed glass and the air of the pores are ultrasonically treated so that the dispersion can sufficiently penetrate the surface and pores of the foamed glass (S80).

A large amount of the dispersion liquid on the surface of the granular foam glass wrapped in a wire net is sufficiently removed to remove the wire mesh to obtain a granular foam glass coated with the dispersion liquid and the foam glass coated with the dispersion liquid is dried at 50 to 80 ° C for 1 to 4 hours (S90 in Fig. 1 and Fig. 7 (b)).

To fix the titanium dioxide coated on the granular foamed glass to the surface of the foamed glass, it is fired at 400 to 700 ° C for 1 to 4 hours to obtain a photocatalyst coated with titanium dioxide on the granular foamed glass (S100 in Fig. 1, Fig. 7 (C)).

A photocatalyst coated with titanium dioxide on granular foamed glass in this way can be used to remove odors.

For example, in order to measure the odor removal efficiency of the photocatalyst produced by the above production method, the photocatalytic malodor processing module shown in FIG. 8 was manufactured. At this time, the efficiency was measured at an average flow rate of 5.6 CFM, an exhaust gas temperature of 24.5 ° C. 1 ° C., and an exhaust gas relative humidity of 80% to 87%.

Item Ammonia (NH3) Trimethylamine (TMA) Acetic acid (AA) Before treatment (low concentration) 0.3 ppm 0.2 ppm 3.5 ppm After processing 0.1 ppm (67%) 0 ppm (100%) 2.25 ppm (36%) Before treatment (high concentration) 70 ppm 50 ppm 8.5 ppm After processing 29.4 ppm (58%) 25 ppm (50%) 3 ppm (65%)

As shown in Table 1, the removal efficiencies of ammonia 67%, trimethylamine 100% and acetic acid 36% were exhibited under the low concentration condition. In the high concentration condition, removal efficiency of ammonia 58%, trimethylamine 50% and acetic acid 65% was shown. This results in lowering the concentration of the initial odorant substance, thereby improving the lifetime and the adsorption efficiency of the adsorption filter.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

Claims (9)

delete Comprising the steps of preparing waste glass in the form of powder, mixing the waste glass in the form of powder with a binder to form a granular shaped molded body, and firing and foaming the granular shaped molded body, Preparing a foamed glass; And
Coating the granular foamed glass with titanium dioxide;
And,
The step of coating titanium dioxide on the granular foamed glass includes a step of firing at 400 to 700 ° C for 1 to 4 hours to fix the titanium dioxide coated on the granular foamed glass to the surface of the foamed glass, Characterized in that said granular foam glass coated with titanium is a photocatalyst for removing odors which can remove a part of ammonia, trimethylamine and acetic acid.
Photocatalyst manufacturing method 3. The method of claim 2,
Coating the granular foamed glass with titanium dioxide, and coating the granular foamed glass with a titanium dioxide dispersion. delete 3. The method of claim 2,
Preparing waste glass in the form of powder; grinding the waste glass; And milling the waste glass. 3. The method of claim 2,
Wherein the binder comprises methyl cellulose or polyvinyl alcohol. ≪ Desc / Clms Page number 20 > The method according to claim 6,
Mixing the powdery waste glass with a binder to form a granular waste glass molded article, wherein the content of the binder in the formed granular shaped article is 1 to 5 wt%. 3. The method of claim 2,
Calcining the granulated shaped body to foam, and calcining the granulated shaped body at 800 to 1100 ° C for 1 to 4 hours. 3. The method of claim 2,
Wherein the waste glass comprises a waste glass of sodium-silicate or boroalumino-silicate composition.

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