KR100978289B1 - Preparation method for adiabatic mortar using low absorption lightweight aggregates made from bottom ash and waste glass - Google Patents

Abstract

PURPOSE: A manufacturing method of insulating mortar is provided to secure the low thermal conductivity, and to install a finishing material without additionally installing the mortar. CONSTITUTION: A manufacturing method of insulating mortar comprises the following steps: mixing bottom ash, waste glass, and a gas foaming agent; inserting a binder to the mixture and pelletizing to make a molded product; coating the surface of the molded product with waste glass powder; plasticizing the molded product inside a rotary kiln to make light weight aggregate; and mixing 5~80 parts of light weight aggregate by weight, and 20~95 parts of cement by weight.

Description

Preparation method for adiabatic mortar using low absorption lightweight aggregates made from bottom ash and waste glass}

The present invention relates to a method for producing insulated mortar, and more particularly, to a method for manufacturing dry insulated mortar mixed with light weight aggregate and cement having low specific gravity and low water absorption produced using bottom ash and waste glass.

General insulation mortars include a mixture of pearlite, vermiculite, foamed styrene and glass hollow bodies, binders such as cement, gypsum and resins, and admixtures such as dispersants, thickeners, heat inhibitors, fasteners, swelling agents, and fibers, depending on the application. It is manufactured in the form of an appropriate dry mix premixed and poured in the field by mixing with water.

The existing insulation mortar is relatively excellent in insulation performance as shown in Table 1 below, but the compressive strength is very low, it is not possible to attach the internal finishing material directly on top of the insulation mortar.

Compressive strength (MPa) Thermal Conductivity (W / mk) Specific gravity (kg / cm ² ) 0.5-15 0.04-0.20 0.3-1.5

Therefore, in order to pour the finishing material, it is necessary to add the material that can express durability and strength such as general mortar and gypsum board after insulated mortar. In order to make up for such drawbacks, it is necessary to develop an insulation mortar that exhibits the same strength as general mortar and has low thermal conductivity.

The present invention provides a method of producing a thermal insulation mortar that does not need to be poured in the durability and strength, such as general plastering mortar or gypsum board additionally after pouring the insulation mortar, while expressing the same strength as the general plaster mortar, but low thermal conductivity Has its purpose.

In the method of manufacturing the insulating mortar of the present invention, the bottom ash is mixed with waste glass and a blowing agent, and pelletized while adding a caking additive to the mixed raw material to prepare a molded body, and then the surface of the manufactured molded body is separated from the waste glass powder. Coated with, and the waste glass powder-coated molded body is baked in a rotary kiln to produce a lightweight aggregate, characterized in that for mixing 5 to 80 parts by weight of the prepared lightweight aggregate and 20 to 95 parts by weight of cement.

In the manufacturing method of the insulating mortar of the present invention, the light weight aggregate has a specific gravity of 0.6 to 1.2, and is characterized in that the water absorption is 6% or less.

In the production method of the insulating mortar of the present invention, the lightweight aggregate is characterized in that the particle size of 0.1 ~ 30 mm.

In the production method of the insulating mortar of the present invention is characterized in that it further comprises at least one admixture selected from thickeners and fibers in the mixture of the light aggregate and cement.

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The thermal insulation mortar prepared by the method of the present invention not only has excellent thermal insulation performance, but also compressive strength is similar to the strength level of general mortar for general plastering, so it is reduced to low strength, which is a disadvantage of conventional thermal mortar, without additional construction of general mortar (wall paper, Tiles, finishing panels for interior and exterior of buildings). In addition, environmentally friendly lightweight aggregates made of waste ash and bottom ash are environmentally friendly and do not generate any harmful substances such as dark lead or asbestos.

In the method of manufacturing the insulating mortar of the present invention, the bottom ash is mixed with waste glass and a blowing agent, and pelletized while adding a caking additive to the mixed raw material to prepare a molded body, and then the surface of the manufactured molded body is separated from the waste glass powder. Coated with, and the waste glass powder-coated molded body is baked in a rotary kiln to produce a lightweight aggregate, and comprises the process of mixing 5 to 80 parts by weight of the prepared lightweight aggregate and 20 to 95 parts by weight of cement.

The light weight aggregate of the present invention has a specific gravity of 0.6 to 1.2 or less than 6% of a water absorption rate, and preferably satisfies both the specific gravity and the water absorption rate conditions. In addition, the lightweight aggregate of the present invention has an average particle size of 0.1 to 30 mm, preferably 1 to 10 mm.

Light weight aggregate of the present invention can be produced through the following process.

First, the bottom ash and waste glass in the step of mixing the bottom ash and waste glass and blowing agent is 0.1: 99.9 to 30: 70 by weight, preferably 10: 90 to 25: 75 by weight. If the bottom ash is less than the lower limit, the moisture absorption of the light weight aggregate is too high, and if the upper limit is exceeded, the specific gravity may exceed 1.2. The foaming agent is 0.1 to 10 parts by weight, preferably 0.2 to 4 parts by weight, more preferably 0.25 to 2 parts by weight based on 100 parts by weight of the bottom ash and the waste glass. If the foaming agent content is less than the lower limit, the specific gravity is too high due to insufficient porosity inside the lightweight aggregate, and if the upper limit is exceeded, even if the lightweight aggregate is coated with waste glass, the fracture strength is lowered and the waste is easily opened due to the crushing. Is increased. The blowing agent of the present invention is preferably calcium carbonate, graphite and iron trioxide (Fe ₂ O ₃ or hematite).

Next, the bottom ash is mixed with the waste glass and the blowing agent, and then pelletized while adding a binder to the mixed raw material to prepare a molded body. The molded article manufacturing step is added 1 to 40 parts by weight of the binder, preferably 20 to 35 parts by weight to 100 parts by weight of the mixed raw materials of the mixing step. It is preferable to use water glass aqueous solution as a caking additive. Water glass aqueous solution is used that 20 to 90% by weight, preferably 40 to 80% by weight of water glass. In the manufacturing method of the molded body of the present invention, the interval between the stirring blades and the bottom surface of the pelletizer is adjusted according to the particle size of the predetermined molded body, and the stirring blade is 1 to 100 minutes at 50 to 1000 rpm, preferably 200 to 500 rpm, Preferably it can be produced by rotating for 5 to 20 minutes.

Next, after forming the molded body, the surface of the molded body is coated with a separate waste glass powder, and the molded body coated with the waste glass powder is fired in a rotary kiln to produce a lightweight aggregate. The coating step of the present invention includes 1 to 60 parts by weight of waste glass powder, preferably 10 to 50 parts by weight, more preferably 25 to 45 parts by weight, in 100 parts by weight of the molded body. If the waste glass powder for coating is less than the lower limit, the specific gravity is low, but the water absorption rate is high. If the waste glass powder for coating is above the upper limit value, the moisture absorption rate is low, but the specific gravity is high. The firing step of the present invention is baked in a rotary kiln at 0.1 to 60 minutes, preferably 1 to 30 minutes at 600 to 1200 ° C, preferably at 800 to 1000 ° C.

The dry specific gravity mortar is prepared by mixing 5 to 80 parts by weight and 20 to 95 parts by weight of the light weight aggregate having a specific gravity of 0.6 to 1.2 and a moisture absorption of 5% or less. Preferably, 10 to 50 parts by weight of light aggregate and 50 to 90 parts by weight of cement are mixed, and the mixing ratio of the light aggregate and cement may be changed according to desired thermal conductivity, specific gravity and compressive strength of the final product. If the content of the light weight aggregate is less than the lower limit, the thermal conductivity is more than 0.4 W / m · k or less, there is a problem that it is difficult to fully exhibit the function as a thermal insulation mortar and specific gravity exceeds 1.8. In addition, when the content of the light weight aggregate exceeds the upper limit, the compressive strength is less than 20 MPa of adiabatic mortar cured in a water bath at 20 ± 2 ℃ for 28 days, it can not exhibit sufficient strength and durability. As the cement used as the binder in the insulating mortar of the present invention, one kind of ordinary portland cement may be used, but a special cement may be used depending on the purpose.

Thickening agents for improving the adhesion properties of the insulating mortar of the present invention, or fibers and the like may be used as admixtures to improve the bending strength and prevent cracking. The amount of the admixture is 0.1 to 20 parts by weight, preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the total aggregate of light weight aggregate and cement.

In the manufactured dry insulation mortar, the mixing weight ratio of water can be adjusted according to the characteristics of the application site, for example, whether it is indoors or outdoors, whether it is a parking lot or a roof, and also, according to the type and content of the admixture, 100 parts by weight of the dry insulation mortar. 1 to 100 parts by weight, preferably 5 to 50 parts by weight of the mixture can be used. At this time, as the amount of water decreases, durability and strength increase, and workability shows a general tendency to decrease.

The thermal conductivity of the thermal insulation mortar of the present invention prepared by the above method was measured by KS L 9016 method of the specimen prepared by mixing the dry thermal insulation mortar with water in a 4: 1 weight ratio of 0.4 W / m · k or less, Preferably it is 0.03-0.3 W / m * k, and the compressive strength (day 28) measured by KSL ISO 679: 2006 method is 20 MPa or more, Preferably it is 20-80 MPa.

Hereinafter, the present invention will be described in detail by way of examples. However, the following examples are merely to illustrate the present invention, but the content of the present invention is not limited thereto.

Preparation Example: Production of Lightweight Aggregate

The bottom ash used in this experiment was generated from Dangjin Coal Fired Power Plant, and used waste glass generated from sheet glass processing.The chemical composition of bottom ash was SiO ₂ as shown in Table 2 below. 43.5 wt%, Al ₂ O ₃ 22.4 wt%, Fe ₂ O ₃ 5.15% by weight, the waste glass was confirmed to be composed of 71.1% by weight of SiO ₂ , 13.1% by weight of Na ₂ O, 8.79% by weight of CaO.

Add 100 parts by weight of calcium carbonate as a blowing agent to 100 parts by weight of bottom ash and main glass, which are the main raw materials, and rotate the stirring blade rotation speed at 300 rpm in a pelletizer with respect to 100 parts by weight of the mixed raw materials. A 5 mm spherical shaped body was prepared by adding 30 parts by weight of an aqueous glass solution of water (water glass: distilled water = 70:30, weight ratio) as a caking agent. The molded product was baked at 900 ° C. for 10 minutes in a rotary kiln to produce lightweight aggregate.

Preparation Examples 1 to 4 were used to replace the bottom ash and waste glass by each content to add calcium carbonate as a blowing agent, and 30 parts by weight of the bottom ash was added to 100 parts by weight of the bottom ash and the waste glass as in Preparation Example 3. It was confirmed that the light weight aggregate was less than 1, and the water absorption gradually decreased from 7.21%.

Table 4 mixes 20 parts by weight and 80 parts by weight of bottom ash and waste glass, respectively, and a water glass aqueous solution (water glass: distilled water = 70: 30, weight ratio) as a binder for stirring blade rotation speed at 300 rpm for 10 minutes in a pelletizer. Was prepared by adding 30 parts by weight of a 5 mm spherical molded body, and then coated by adding 1 to 50 parts by weight of waste glass powder with respect to 100 parts by weight of the molded body, respectively. It shows the physical properties of the aggregate.

When the waste glass powder was coated up to 40 parts by weight with respect to 100 parts by weight of the molded body, the specific gravity and water absorption were remarkably reduced, and at 50 parts by weight or more, the result was similar to 40 parts by weight.

Preparation Example: Preparation of Insulation Mortar

Insulating mortar was prepared using the lightweight aggregate of Preparation Example 7. Figure 1 is a photograph showing the appearance of the lightweight aggregate of Preparation Example 7, Figure 2 is an enlarged photograph showing the inner pores and outer coating layer of the lightweight aggregate.

The light weight aggregate of Preparation Example 7 and one type of ordinary portland cement were mixed in the mixing ratios of Table 5 to prepare the insulation mortars of Comparative Examples 1 and 1 to 4.

Comparative Example 1 is not using a lightweight aggregate, Comparative Example 2 is prepared by using a commercial lightweight aggregate having a specific gravity of 1.3 and a water absorption of 25%, Comparative Example 3 is a thermal insulation mortar currently on the market using a pearlite insulating material.

Experimental Example 1 Measurement of Compressive Strength

Compressive strength was mixed with dry mortar and water in the ratio of 4: 1 in a weight ratio of 4: 1, and then cured in water for 3 days, 7 days, 28 days in a 20 ± 2 ℃ water bath after molding by the KS L ISO 679: 2006 method. Sectional photographs of the thermal insulation mortar cured under water for 28 days of Examples 1 to 3 are shown in FIGS. 3 to 5, respectively. The thermal insulation mortar cured for the predetermined period was measured by the KS L ISO 679: 2006 method and the results are shown in Table 6 and FIG. 6.

Experimental Example 2: Measurement of Thermal Conductivity

In order to measure the thermal conductivity, a panel for measuring thermal conductivity was prepared by curing under water in a 20 ± 2 ° C. water bath at the same mixing ratio and mixing amount as in Experimental Example 1. 7 to 9 show photographs of the panels after the underwater curing of Examples 1 to 3, respectively.

The thermal conductivity of the prepared panel was measured by mounting on a thermal conductivity tester (HC-074, EKO, Japan) applying the plate heat flow meter method. There are various methods of measuring thermal conductivity, but the test was conducted according to the flat plate heat flow meter method specified in "Measuring Thermal Conductivity of KS L 9016-Insulating Material". In the plate heat flow meter method, the heat flow rate passing through the test body is measured by a heat flow meter, and the thermal conductivity is obtained by measuring the temperature difference at that time. The measurement principle is shown in FIG. 10, and in FIG. 11, the thermal conductivity tester used for the measurement is photographed. As shown.

Thermal conductivity values and specific gravity of the panel are shown in Table 7 FIG.

1 is a photograph showing the appearance of the lightweight aggregate of Preparation Example 7.

Figure 2 is an enlarged photograph showing the inner pores and the outer coating layer of the lightweight aggregate of Preparation Example 7.

Figure 3 is a cross-sectional photograph of the thermal insulation mortar cured in 28 days of Example 1.

Figure 4 is a cross-sectional photograph of the thermal insulation mortar cured in 28 days of Example 2.

5 is a cross-sectional photograph of the thermal insulation mortar cured in 28 days of Example 3.

6 is a graph showing the compressive strength of Comparative Examples and Examples.

7 is a photograph of the thermal insulation mortar panel cured in 28 days of Example 1.

FIG. 8 is a photograph of an insulation mortar panel cured under water for 28 days in Example 2. FIG.

FIG. 9 is a photograph of an insulation mortar panel cured in water for 28 days in Example 3. FIG.

10 is an explanatory diagram showing a principle of thermal conductivity measurement.

11 is a photograph showing a thermal conductivity measuring apparatus used in Experimental Example 2.

12 is a graph showing thermal conductivity of Comparative Examples and Examples.

Claims (5)

The bottom ash is mixed with the waste glass and the blowing agent, and pelletized while adding a binder to the mixed raw material to prepare a molded body, and then the surface of the manufactured molded body is coated with a separate waste glass powder, and the waste glass powder is The coated molded body is fired in a rotary kiln to produce a lightweight aggregate, and the method for producing an insulating mortar mixing 5 to 80 parts by weight of the prepared lightweight aggregate and 20 to 95 parts by weight of cement. The method of claim 1, wherein the light weight aggregate has a specific gravity of 0.6 to 1.2, the absorption method of 6% or less, characterized in that the manufacturing method of the mortar. The method of claim 1, wherein the lightweight aggregate is a method of producing a thermal insulation mortar, characterized in that the particle size of 0.1 ~ 30 mm. The method of claim 1, wherein the mixture of lightweight aggregate and cement further comprises at least one admixture selected from thickeners and fibers. delete

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