KR100281793B1 - Method of light block with waste glass of soda-lime glass silicate - Google Patents

Abstract

(Purpose) Provides a method for producing foamed glass based on waste glass, which has open pores, which causes poor insulation and soundproofing, moisture absorption, freezing, foaming on the inner side, non-uniform foaming, and good productivity. The purpose.

(Composition) A uniform mixture of carbon and fine glass powder was put in a mold coated with an alumina slurry with a mold release agent on a metal mold, and the temperature was increased to 5 to 8 ° C / min in an electric muffle furnace and 730 ° to 780 ° C. After maintaining for 30 minutes at a second temperature increase rate of 1 ° ~ 5 ° C and maintained for 30 minutes at 920 ° ~ 980 ° C to produce a lightweight aggregate made of waste glass.

Description

Manufacturing Method of Light Weight Aggregate Made from Waste Glass of Soda-lime Silicate {METHOD OF LIGHT BLOCK WITH WASTE GLASS OF SODA-LIME GLASS SILICATE}

The present invention relates to a method for producing expanded glass for use as lightweight aggregates based on waste glass of soda lime silicate. Foamed glass refers to glass containing a lot of pores, and because of its pore structure, the glass has good thermal insulation, light weight, and processability, and has properties such as weather resistance and chemical resistance, which are inherent physical properties of glass.

Foamed glass is made by mixing carbon powder and carbon with proper particle size and putting it in the mold of the desired form. The principle of foamed glass is as follows. When the mixture of glass powder and carbon is heated above a certain temperature, the glass softens and surrounds carbon. When the mixture is heated to a higher temperature, SO ₃ and carbon, which exist in the gas state inside the glass powder, react as shown in the following formula. This gas causes the softened glass to swell, producing foamed glass.

SO ₃ + 2C → S ^2- + CO (gas) + CO ₂ (gas)

Therefore, in order to manufacture homogeneous free-standing porous glass, the heating temperature is

It must be higher than the softening temperature of the glass used as a raw material, and carbon should not react with oxygen in the atmosphere until this time as possible, and then, when heated to higher temperature, SO ₃ and carbon inside the glass react well to generate gas. . In short, the softening temperature, gas content, and powder particle size of the glass powder used are very important. For this reason, foamed glass for thermal insulation is generally manufactured by melting a glass of a specially designed composition and pulverizing it to prepare a glass powder and then using it as a raw material.

In the heat treatment, the initial primary temperature increase rate is poorly controlled, which increases the possibility of open pores, thus absorbing moisture, deteriorating heat insulation and sound insulation, and being absorbed, resulting in freezing and controlling temperature retention time even after the temperature is elevated. If not, the outer part is foamed, but the inner part is un foamed,

In addition, even at the second temperature increase rate, the productivity is worse when low, and when it is high, foaming becomes incurable,

Even after the second temperature rise, if the holding time of the high temperature is not well controlled, there is a problem that the foamability is poor and the non-uniform foaming.

In order to solve the above problems, it is an object of the present invention to provide a method for producing lightweight aggregates based on waste glass with good productivity without opening pores, thus not absorbing moisture or freezing and uneven foaming of the inner part. .

1 is a heat treatment schedule when manufacturing the foam glass of the present invention

Figure 2 is a photograph of the fracture surface structure of the foam glass of Example 1

Figure 3 is a fracture surface texture photograph of the foam glass of Example 2

In order to solve the above problems, a mixture of carbon and fine glass powder uniformly was put in a mold coated with an alumina slurry with a mold release agent on a metal mold, and the temperature was raised to 5 to 8 ° C / min in an electric muffle furnace. A lightweight aggregate made from waste glass of soda-lime silicate, which is maintained at 30 ° C. for 30 minutes at a temperature of 1 ° -5 ° C. and then maintained at 920 ° C.-980 ° C. for 30 minutes, is produced.

(Detailed embodiment of the invention)

When the temperature rises from 5 ° to 8 ° C., the pores are formed, the heat insulation and sound insulation are poor, and the freezing becomes less than 30 minutes at 730 ° to 780 ° C. Even at an elevated temperature, the productivity is poor at less than 1 ° C, and the foaming becomes uneven when it exceeds 5 ° C, and when the temperature is lower than 920 ° C, the foamability is bad.

The present invention relates to a method for producing a foam for insulation of homogeneous independent pore structure by strictly controlling the particle size and heat treatment process using the raw glass pulverized product of the general soda lime silicate composition, not the glass for the specifically designed composition.

In this example, an important point is whether the carbon used as the blowing agent is crystalline. Carbon is largely divided into crystalline carbon and amorphous amorphous carbon. When heated in the atmosphere, amorphous carbon such as carbon black starts to oxidize at about 300 ° C. or lower, and at 70 ° C., about 70% is oxidized and lost, while crystalline carbon is lost. Depending on the degree of crystallization, in the case of the graphite powder used in the present embodiment, since oxidation starts at about 720 ° C., oxidation starts at a temperature higher than the softening temperature of the plate glass. The second important thing is the particle size of the glass. The glass is softened even if the glass is of the same composition, depending on the particle size, the glass not only has a different temperature surrounding the carbon, but also because the temperature that reacts with the carbon to release the sulfide inside. Sulfide inside glass naturally melts into the glass with non-stoichiometric combustion of sulfur components when burning fossil fuel in a tank furnace. It is common. The heat treatment schedule is as shown in FIG. 1 for the following reason. Up to 750 ° C, the first holding temperature, at a rate of 8 ° C per minute, is to surround the carbon with glass before carbon is oxidized as much as possible, and holding it at this temperature for 30 minutes gives time to transfer the temperature to the interior. . Later, the temperature was raised to 3 ° C / min until the second holding temperature, 950 ° C, to give enough time for the SO ₃ and carbon inside the glass to react to produce a gas, which inflates the softened glass. The 30 minute hold time was intended to give the temperature a uniform temperature inside, as in the first.

Example of the present invention is part of the optimum blowing agent and heat treatment schedule found through many experiments and observations in order to produce a homogeneous independent pore tissue foam glass using waste glass of the plate glass of soda lime silicate composition.

For example, it will be described in detail as follows.

Example 1

Waste glass of soda lime silicate composition plate glass was collected and pulverized using Jaw Crusher and Ball Mill. At this time, the particle size was 200mesh or less. 0.5 parts by weight of carbon was uniformly mixed with 100 parts by weight of this glass powder using a V-mixer. In this case, carbon having a central particle diameter of 5 µm that is hardly oxidized at about 715 ° C., which is a softening temperature of the raw material glass, was used. The above mixture was put into a metal mold coated with an alumina (Al ₂ O ₃ ) slurry as a release agent having a size of 20 cm × 20 cm × 30 cm, and heat-fired by heat treatment as shown in FIG. The properties of the foamed glass thus prepared were measured by the American Material Test Standard (ASTM C552-91) to obtain the following values. Density of 330 kg / m ³ , compressive strength of 720 kPa, absorption of 0.5% or less, thermal conductivity of 0.058 W / m · K (38 ° C.), 0.053 W / m · K (24 ° C.), and 0.049 W / m · K (10 ° C.). Fig. 2 shows an enlarged structure in which the fracture surface of the foamed glass of Example 1 was observed under a microscope. It can be seen that it became a homogeneous free-standing foam glass.

Example 2

Plate glass was pulverized as in Example 1 to make a glass powder of 150mesh or less. 0.7 parts by weight of carbon was uniformly mixed with 100 parts by weight of the glass powder using a V-mixer. In this case, carbon having a central particle diameter of 5 µm that is hardly oxidized at about 715 ° C., which is a softening temperature of the raw material glass, was used. The above mixture was placed in a metal mold coated with an alumina (Al ₂ O ₃ ) slurry as a release agent having a size of 20 cm × 20 cm × 30 cm, and heated and baked in an electric muffle to prepare a foamed glass. The heat treatment schedule was two stage heating as shown in FIG. 1, but the temperature was different from that of Example 1 at the primary holding temperature of 760 ° C and the secondary holding temperature of 930 ° C. So manufactured

The properties of the foamed glass were measured by American Material Test Standard (ASTM C552-91) to obtain the following values. Density 350 kg / m ³ , compressive strength 730 kPa, absorption rate 0.5% or less, thermal conductivity 0.059 W / m · K (38 ° C.), 0.055 W / m · K (24 ° C.), 0.051 W / m · K (10 ° C.).

3 shows an enlarged structure in which the fracture surface of the foamed glass prepared in FIG. 3 was observed under a microscope. It can be seen that it became a homogeneous free-standing foam glass.

Open pores are not formed in the foamed glass, and therefore, the heat insulating and soundproofing properties are good, and there is no freezing, the productivity is good, and the foaming is uniform.

Claims (2)

The mixture of carbon and fine glass powder uniformly was put in a metal mold coated with a releasing agent, and the temperature was increased to 5 to 8 ° C./min in an electric muffle furnace and maintained at 730 ° to 780 ° C. for 30 minutes. A method for producing a lightweight aggregate based on waste glass of soda lime silicate, characterized in that the temperature rise rate is 1 ° to 5 ° C. and maintained at 920 ° to 980 ° C. for 30 minutes. The method for producing a lightweight aggregate based on waste glass of soda lime silicate according to claim 1, wherein the glass powder is 150 to 200mesh.