KR100221402B1 - Method for preparing activation of clay - Google Patents

Abstract

The loess activation method of the present invention heats up the loess to 400 ° C. in the shortest time possible. The loess heated to 400 ° C. is heated at high temperature to 1000 ° C. for at least 1 minute. By quenching, and crushing the quenched ocher to have a particle size of an appropriate size depending on the intended use. Since the loess activated by the activation method of the present invention reacts with calcium hydroxide to cause a curing reaction, aplite, a stabilized pozzolanic product, is produced when used in combination with lime. Lime mixed with activated loess causes hydration with water and expands its volume to prevent cracking of the loess. The loess activated by the activation method of the present invention can exhibit the original physical properties and effects of the loess because it can form a mortar composition using only lime without using cement.

Description

[Name of invention]

How to activate ocher

Detailed description of the invention

[Field of Invention]

The present invention relates to loess that can be used as a building material. More specifically, the present invention relates to a method for activating loess that can be used in all building materials using loess, including loess mortar compositions prepared using loess.

[Background of invention]

In our traditional building culture, ocher has been used as one of the important building materials. In particular, the loess of Korea is known to generate far infrared rays with a wavelength of 6 to 15㎛, and also has insect repellent properties against pests and insects, exhibits chemical effects such as deodorization, and shows excellent effects in regulating heat storage and humidity. It has been found to have various positive effects on human health.

However, ocher has the drawback that its binding strength is weak. Therefore, in the related art, finely cut rice straw and the like have been mixed with loess to enhance the bonding force of the building material using loess. Recently developed technologies include the production of building materials by mixing inorganic binders such as cement or other organic binders with loess. In addition, a large amount of expansion agent is sometimes used to prevent cracking during drying. These building materials made of loess contain materials such as inorganic binders, organic binders and other expandables, so it is difficult to expect the inherent superior properties or effects of the soil.

The present inventors have already developed a method of activating kaolin which can replace a part of cement in the case of manufacturing a conventional mortar or concrete, and the method of activating kaolin is Korean Patent Application No. 96-38841 (1996) Filed September 9).

The present inventors have developed a method for activating loess, which can be used in combination with lime without using cement or an expanding agent, and further enable the building material according to the present invention to exhibit excellent physical properties or effects of loess.

[Purpose of invention]

It is an object of the present invention to provide a method for activating loess that can be used as a building material.

Another object of the present invention is to provide an activated loess which can produce ocher building materials that can exhibit the properties or effects of loess without the use of cement or an expanding agent.

It is yet another object of the present invention to provide activated loess which can produce ocher building materials that can improve cracking and prevent cracking.

The above and other objects can be achieved by the present invention described below.

[Summary of invention]

The loess activation method of the present invention heats up the loess to 400 ° C. in as short a time as possible, and fires the loess heated to 400 ° C. at a high temperature while raising the temperature to at least 1 minute to 1,000 ° C. By quenching, and crushing the quenched ocher to have a particle size of an appropriate size depending on the intended use.

Since the loess activated by the activation method of the present invention reacts with calcium hydroxide to cause a curing reaction, aplite, a stabilized pozzolanic product, is produced when used in combination with lime. Lime mixed with activated ocher causes hydroxyl reaction with water to expand its volume, which can prevent cracking of the ocher. The loess activated by the activation method of the present invention can exhibit the original physical properties and effects of the loess because it can form a mortar composition using only lime without using cement.

Hereinafter, the details of the present invention will be described below.

Detailed Description of the Invention

The activated ocher of the present invention uses loess which is abundantly buried in Korea. Until now, loess has been used as a building material by mixing with cement, swelling agent, rice straw, etc., but the present invention is to provide loess activated for use in mixing with lime without mixing with these materials and its activation method. .

Activation of minerals means that when a material is energized and then cooled, the material does not have time to crystallize, so that it retains high crystallization energy inside and becomes a glass state with the possibility of chemical bonding due to external stimulation at any time. Say. When ocher is made into active ocher by this treatment, it becomes high energy state and its reactivity is increased, but even if the powder is contacted with water as it is, the hydration reaction is hardly progressed. It was found to have. In the present invention, the loess is activated to have latent hydraulic properties.

In other words, when the loess is made into activated loess through the process of temperature rising, high temperature firing, quenching, etc., the loess becomes high energy state, but the reactivity increases. It is very noticeable when the hydraulic potential is called. In the present invention, the loess is activated to have latent hydrophobicity, which is placed under a specific condition of morter, thereby showing a mechanism for causing a hydration reaction and a pozzolanic reaction.

The loess activation method of the present invention heats up the loess to 400 ° C. in as short a time as possible, and fires the loess heated to 400 ° C. at a high temperature while raising the temperature to at least 1 minute to 1,000 ° C. By quenching, and crushing the quenched ocher to have a particle size of an appropriate size depending on the intended use.

The naturally dried raw loess at room temperature is heated to 400 ° C. over 1 hour. In consideration of thermal efficiency and energy, it is economically advantageous to raise the temperature in the shortest time possible.

The ocher heated to 400 ° C. is calcined while gradually heating up to 100 ° C. In this high temperature baking process at 1,000 ° C, it is preferable to bake at a uniform temperature to the inside of the loess by firing for at least 1 minute as much as possible. However, high temperature firing should be carried out in consideration of thermal efficiency and the amount of energy used, and at least one minute should be carried out in consideration of physical properties. In addition, in the high temperature firing process, it should not be more than 1,000 ℃, because when it is more than 1,000 ℃ deteriorates the physical properties of the activated loess.

Loess which has been fired at high temperature is quenched using air or water. Since the quenching method using water is cheaper than the method using air, the quenching method using water may be preferably used. By quenching hot-baked loess, active loess can be produced in which energy is conserved therein.

The quenched ocher is crushed to a particle size of about 250 mesh, and can be crushed to an appropriate size depending on the intended use. Activated ocher ground to about 250 mesh has a specific surface area of about 2000 cm 2 / g.

Since the loess activated by the activation method of the present invention reacts with calcium hydroxide to cause a curing reaction, aplite, a stabilized pozzolanic product, is produced when used in combination with lime.

As a result of stirring the activated loess according to the present invention by stirring each of the solidified mass in water and a sample kneaded with a calcium hydroxide solution, the test piece kneaded in water was kneaded again in water and kneaded in a calcium hydroxide solution. One loess remained in an insoluble mass. As a result, the activated ocher of the present invention can be seen that the curing reaction occurs by the pozzolanic reaction with calcium hydroxide. This is because the silica component in loess is combined with calcium hydroxide produced during lime hydration to produce a stabilized pozzolanic product, aporite, and the chemical reaction formula is as follows.

3Ca (OH) ₂ + 2SiO ₂ → 3CaO · 2SiO ₂ · 3H ₂ O: stable

Lime mixed with activated loess causes hydration with water and expands its volume to prevent cracking of the loess.

When the ocher reacts with water, the volume decreases due to the aggregation phenomenon between the particles, which is the main reason for cracking when using the conventional ocher dough. When lime is added to it, quicklime causes hydration, causing volume expansion, and by controlling the contracted expansion between them, cracks can be controlled. This is done using chemical prestress, and the chemical equation for this is as follows.

CaO + H ₂ O → Ca (OH) ₂ volume expansion

The activated ocher of the present invention is mixed with lime in a ratio of about 2: 1 or so that the content of activated ocher is in a smaller ratio, and the mixture is mixed with aggregate again to prepare a mortar composition. The ratio of the mixture and aggregate is preferably about 6: 4, and the ratio may be appropriately adjusted depending on the use base.

The present invention can provide an activated loess that can be used to produce loess building materials that can exhibit the properties or effects of loess without the use of cement or swelling agents.

The mortar using the activated ocher of the present invention has good far-infrared emissivity, better variation in length than conventional cement mortar, good compressive strength and solidification time, and no crack after drying shrinkage. have.

The present invention will be further illustrated by the following examples, which are only described for the purpose of illustrating the present invention and are not intended to limit the protection scope of the present invention.

EXAMPLE

Example 1

(1) production of activated ocher

The natural loess was sufficiently dried and then heated to 400 ° C. for 1 hour, and heated to 1,000 ° C. for 1 minute at a temperature of 1,000 ° C. for 1 minute. The hot-fired ocher was quenched with water and then pulverized into 250 mesh to obtain activated ocher having a specific surface area of about 2000 cm 2 / g.

(2) Preparation of activated ocher mortar

The activated ocher mortar is mixed with lime having a CaO content of 95% or more and a specific surface area of about 5000 cm 2 / g so that the activated ocher is 1: 2, and the sand having a particle size of 2.5 mm or less is mixed with 6: 4 in the mixture. Was prepared. Each sample was weighed and premixed, and then water was added thereto, followed by 1 minute at low speed and 2 minutes at high speed. The curing room maintained a normal standard temperature of 20 ± 2 ° C. and a humidity of 65 ± 5%. Table 1 shows the physical properties of the activated ocher mortar.

Comparative Example 1

Mortar was prepared in the same manner as in Example 1 except for using unactivated natural loess instead of activated loess. Table 1 shows the physical properties of the unactivated ocher mortar of Comparative Example 1.

Comparative Example 2

Cement mortar was prepared by mixing sand having a particle size of 2.5 mm or less in cement at 1: 3. Physical properties of the cement mortar were measured and shown in Table 1.

Physical property measurement:

The measurement method of the physical properties measured in Examples and Comparative Examples is as follows.

1. Far-infrared emissivity measurement

Far infrared rays emitted were measured using a specimen of 30 × 30 × 5 mm.

2. Infrared thermography

Infrared infrared images were measured using a 30 × 30 × 5 mm specimen.

3. Length change test

It tested by JIS-A-1129. The sample was poured into a mold of 3 × 3 × 30 cm, but was molded by attaching a length-change measuring plate to both ends of the sample. After 1 day, the mold was demoulded, and the length change was measured up to 28 days.

4. Compressive strength test

It was tested according to 9.4, 9.5 and 9.6 of JIS-R-5201. The mortar was injected into the mold (40 × 40 × 160 mm), but about 5 mm higher than the mold. After staying in the wet curing room for 2 hours or more, the sample was scraped off in accordance with the upper surface of the mold. After curing for 48 hours in the wet curing room and demolded. After demolding, the solution was cured for 28 days in the curing room.

5. Condensation time

The condensation time was measured early and the termination time was visually measured.

6. Shrink Crack Test

The test was carried out in three molds having a width x height x length of 2.5 cm x 1 cm x 180 cm, and the number of cracks generated after 7 days of curing was examined.

All simple modifications or changes of the present invention can be easily carried out by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.

Claims (6)

Heating the naturally dried raw material loess to 400 ° C. as short as possible; Ocher heated to 400 ° C. at high temperature while raising the temperature to 400 ° C. for at least 1 minute; Quenching hot-baked ocher to room temperature; And pulverizing the loess quenched to room temperature. 2. The method of claim 1, wherein the raw loess is heated to 400 ° C within 1 hour. 2. The method of claim 1, wherein the hot-fired loess is quenched using water or air. The method of claim 1, wherein the finely ground loess is an average particle diameter of about 250 mesh. The naturally dried raw material ocher is heated to 400 ° C. in the shortest time possible, and the heated ocher heated to 400 ° C. is heated at a temperature of at least 1 minute and raised to 1,000 ° C. at a high temperature, quenched to room temperature, and pulverized. Activated ocher powder. Activated ocher prepared by heating the naturally dried raw material loess to 400 ° C. in the shortest time possible, heating the loess heated to 400 ° C. at a temperature of at least 1 minute and raising it to 1,000 ° C., quenching to room temperature, and pulverizing. Mortar composition consisting of lime, and aggregate.