KR20100107747A - A production method of an artificial aggregate and an artificial aggregate produced by the same - Google Patents

Abstract

PURPOSE: A manufacturing method of artificial aggregate, and the artificial aggregate manufactured therefrom are provided to reduce the environmental contamination by recycling electric furnace oxidizing slag powder and wastewater treatment sludge. CONSTITUTION: A manufacturing method of artificial aggregate comprises the following steps: mixing first electric furnace oxidizing slag powder with the particle diameter of 0~1 millimeters, second electric furnace oxidizing slag powder with the particle diameter of 1~5 millimeters, limestone sludge, wastewater treatment sludge, and water to form a mixture(A); adding cement to the mixture to form a particulate(B); adding the cement and the water to the particulate to coat the surface of the particulate(C); and drying the coated particulate(D).

Description

Production method of an artificial aggregate and an artificial aggregate produced by the same}

The present invention relates to a method for producing artificial aggregate and to an artificial aggregate prepared by the above method, and more particularly, to a method for producing artificial aggregate and recycling the fine powder generated when crushing and screening oxidized slag by electricity. It relates to artificial aggregate.

Although the steel process uses a large amount of raw materials and energy, there is an environmental problem that generates a large amount of waste by-products. On the other hand, slag is a by-product that accounts for about 80% of the by-products generated during the steel process. Among slag, electric furnace slag is a by-product that generates about 3.8 million tons per year, and is mostly used as a low aggregate for filling, or base and subbases. Such slag contains a large amount of CaO in nature. Free-CaO (free-CaO), which does not stabilize as a crystalline phase in CaO, is present as a glass phase in slag, changes to Ca (OH) ₂ when reacting with water in air, causing volume change, and expanding when used as aggregate. It can cause cracks and the like. Therefore, slag is sprinkled for a certain period of time depending on the particle size after crushing to stabilize the hydration expandability. Recycling instructions). During the crushing process of the slag, fine powder is generated, which is not the desired particle size. Such fine powder is not recycled at present, and there is insufficient recognition and research on recycling.

It is an object of the present invention to provide a method for producing artificial aggregate for recycling oxidized slag fine powder and wastewater treatment sludge and an artificial aggregate prepared by the above method.

It is an object of the present invention to provide a method for producing artificial aggregate which can reduce environmental pollution and an artificial aggregate prepared by the above method.

In order to solve the above problems, the present invention (A) the first furnace oxide slag having a particle size of more than 0 and less than 1mm, the second furnace oxide slag having a particle size of 1mm to 5mm, limestone sludge, wastewater treatment sludge and water residual amount Mixing to form a mixture; (B) adding cement to the mixture to form granules; (C) coating the granular surface by adding cement and water to the granular body; And (D) drying the surface-coated granules.

In addition, the present invention is composed of a first electric furnace oxide slag having a particle size greater than 0 and less than 1 mm, a second electric furnace oxide slag having a particle size of 1 mm to 5 mm, limestone sludge, wastewater treatment sludge and cement, the surface of which is coated with cement It provides an artificial aggregate characterized by.

The artificial aggregate of the present invention can recycle the oxidized slag fine powder and the wastewater treatment sludge with electricity to be treated waste, thereby reducing the environmental pollution.

Hereinafter, a method of manufacturing artificial aggregate according to the present invention will be described in more detail below.

1 is a flow chart illustrating a method of manufacturing artificial aggregate of the present invention.

Referring to Figure 1, the manufacturing method of the artificial aggregate of the present invention comprises the steps of (A) mixing the first electric furnace oxide slag, the second electric furnace oxide slag, limestone sludge, wastewater treatment sludge and water to form a mixture do.

Here, the first furnace oxide slag and the second slag are fine powders generated during the crushing of the furnace oxide slag, and are separated into particle sizes by particle size selection. The particle size of the first furnace oxide slag is greater than 0 and less than 1 mm, and the particle size of the second furnace oxide slag is 1 mm to 5 mm. The limestone sludge, which is generated during the limestone firing process, is preferably applied to the present invention after the dehydration and drying process. The wastewater treatment sludge is preferably applied to the present invention after the dewatering and drying process as organic sludge generated during the wastewater treatment process.

In the step (A), based on the total weight of the mixture, the first furnace oxide slag 10 to 20% by weight, the second furnace oxide slag 20 to 60% by weight, the limestone sludge is 10 to 40% by weight, the Wastewater treatment sludge is preferably mixed with 10 to 25% by weight and the balance of water. Including the above constituents in the above range has the advantage of improving the strength of the final product.

Method for producing artificial aggregate of the present invention (B) comprises the step of forming a granule by adding cement to the mixture. The step (B) is preferably made in a stirring state, preferably stirred at a speed of 40 to 50rpm with a drum type stirrer. The cement is preferably added in 2 to 6 parts by weight based on 100 parts by weight of the mixture. When the cement is added to the above-described range, the mixture grows in size while forming a small spherical shape in a dough mass, and thus becomes easily granular. It is preferable that the granular body has a particle size of 5 to 20 mm.

The method for producing artificial aggregate of the present invention includes (C) adding the cement and water to the granular body and coating the granular surface. The cement and water are preferably added in an amount of 1 to 3 parts by weight and 0.5 to 1.5 parts by weight, respectively, based on 100 parts by weight of the granular material. When the cement and water are added in the above-described range, respectively, the granules may be further granulated to form a stabilized spherical body.

Method for producing artificial aggregate of the present invention includes the step of (D) drying the granules coated with the surface. In the step (D), it is preferable to perform a carbon dioxide gas stabilization treatment process before drying the surface-coated granules. The carbon dioxide gas stabilization process is preferably carried out for 30 to 40 hours. The carbon dioxide gas stabilization process may be carried out in a drum-type reactor, wherein the temperature is 80 to 90 ℃, containing water vapor, it is preferable that the conditions are just passed through CO ₂ .

In addition, the step (D) may further comprise the step of separating the particle size of the dried granules, after the step of drying the surface-coated granules. Through particle size separation of the granular body, it is possible to provide an artificial aggregate in accordance with the intended use.

In addition, the present invention provides an artificial aggregate.

Artificial aggregate according to the present invention is composed of a first electric furnace oxide slag having a particle size greater than 0 and less than 1 mm, a second electric furnace oxide slag having a particle size of 1 mm to 5 mm, limestone sludge, wastewater treatment sludge and cement, the surface is coated with cement do.

In addition, the artificial aggregate is 10 to 20% by weight of the first furnace oxidized slag based on the total weight of the mixture; 20 to 60% by weight of the second electric furnace oxide slag; 10 to 40% by weight of the limestone sludge; 10 to 20% by weight of the wastewater treatment sludge; And mixing the remaining amount of water to form a mixture; (B) adding 2 to 6 parts by weight of cement based on 100 parts by weight of the mixture to form a granule; (C) coating the granular surface by adding 1 to 3 parts by weight of cement and 0.5 to 1.5 parts by weight of water based on 100 parts by weight of the granular material; And (D) drying the surface-coated granules. The detailed manufacturing method is omitted since it has already been described above.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the examples and the like described below are for illustrating the present invention, and the present invention is not limited thereto and may be variously modified and changed.

Example 1 Preparation of Artificial Aggregate

With respect to the total weight of the mixture, 15 wt% of the first furnace oxide slag, 40 wt% of the second furnace furnace oxide slag, 30 wt% of the limestone sludge, 15 wt% of the wastewater treatment sludge and the balance of the water were mixed to form a 100 kg mixture. . The mixture was added with 4 kg of cement while stirring at 45 rpm in a drum stirrer, followed by continuous stirring to form a granule having a particle size of 15 mm. The granular material was 100 kg by evaporation of water during the stirring process. 2 kg of cement and 1 kg of water were added to the granules to form a spherical body by coating the surface. The spherical body was subjected to carbon dioxide stabilization for 35 hours in a drum-type reactor, and dried to complete an artificial aggregate.

Comparative Example 1: Preparation of Crushed Aggregate

After the raw stone was crushed for aggregate use, impurities such as fine powder were removed to prepare crushed aggregate.

Test Example 1: Evaluation of Properties of Artificial Aggregates and Crushed Aggregates

Physical property evaluation of the artificial aggregate of Example 1 and the crushed aggregate of Comparative Example 1 was performed. The physical property measurement method is shown below.

<Test method>

Absolute dry density of coarse aggregate: KSF2504

Unit volume mass of aggregate: KSF2505

Absorption Rate of Coarse Aggregate: KSF2504

Wear test of coarse aggregate by Los Angeles testing machine: KSF2508

Performance ratio of aggregates: KSF2505

Test method for alkali latent reaction of aggregate: KSF2546

Absolute dry density Unit volume mass Absorption rate Wear rate Performance rate Alkali aggregate reaction Example 1 2.88 1.8 2.65 23.2 64.3 60 Comparative Example 1 2.68 1.613 1.6 22.5 60 58

Referring to Table 1, the artificial aggregate of Example 1 and the crushed aggregate of Comparative Example 1 showed almost similar physical properties. Therefore, in the case of artificial aggregate according to the present invention, it can be seen that it can be used as aggregate even though recycled materials are used.

1 is a flow chart showing a method of manufacturing artificial aggregate according to the present invention.

Claims (10)

(A) mixing a first electric furnace oxide slag having a particle size greater than 0 and less than 1 mm, a second electric furnace slag having a particle size of 1 mm to 5 mm, limestone sludge, wastewater treatment sludge and water to form a mixture; (B) adding cement to the mixture to form granules; (C) coating the granular surface by adding cement and water to the granular body; And (D) a method for producing an artificial aggregate, characterized in that it comprises the step of drying the surface-coated granules. The method according to claim 1, Step (A) is With respect to the total weight of the mixture, 10 to 20% by weight of the first electric furnace oxide slag; 20 to 60% by weight of the second electric furnace oxide slag; 10 to 40% by weight of the limestone sludge; 10 to 20% by weight of the wastewater treatment sludge; And Method for producing an artificial aggregate, characterized in that to form a mixture by mixing the remaining amount of water. The method according to claim 1, The step (B) is a method for producing artificial aggregate, characterized in that made in a stirred state. The method according to claim 1, Step (B) is a method for producing an artificial aggregate, characterized in that for adding 100 parts by weight of the mixture, 2 to 6 parts by weight of the cement. The method according to claim 1, The particle size of the granules in the step (B) is a method for producing artificial aggregate, characterized in that 5 to 20mm. The method according to claim 1, Step (C) is a method for producing artificial aggregate, characterized in that the cement is added to 1 to 3 parts by weight, the water is 0.5 to 1.5 parts by weight based on 100 parts by weight of the granular body. The method according to claim 1, Step (D) is a method for producing artificial aggregate, characterized in that to perform a carbon dioxide gas purification treatment step before drying the surface-coated granules. The method according to claim 1, The step (D) is a method for producing an artificial aggregate, characterized in that further comprising the step of separating the particle size of the dried granules, after drying the surface-coated granules. An artificial aggregate comprising a first electric furnace oxide slag having a particle size greater than 0 and less than 1 mm, a second electric furnace oxide particle having a particle size of 1 mm to 5 mm, limestone sludge, wastewater treatment sludge and cement, and the surface of which is coated with cement. . The method according to claim 9, 10-20% by weight of the first furnace oxide slag, based on the total weight of the mixture; 20 to 60% by weight of the second electric furnace oxide slag; 10 to 40% by weight of the limestone sludge; 10 to 20% by weight of the wastewater treatment sludge; And mixing the remaining amount of water to form a mixture; (B) adding 2 to 6 parts by weight of cement based on 100 parts by weight of the mixture to form a granule; (C) coating the granular surface by adding 1 to 3 parts by weight of cement and 0.5 to 1.5 parts by weight of water based on 100 parts by weight of the granular material; And (D) artificial aggregate, characterized in that the step of drying the surface-coated granules are manufactured.

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