KR101159958B1 - Manufacturing method for asphalt pavement aggregate using electricfurnace oxidized slag - Google Patents

Abstract

The present invention relates to a method for producing asphalt pavement aggregate and asphalt concrete aggregate using an electric furnace oxidized slag, the first iron component separation step of separating the iron-containing components in the molten oxide slag discharged from the electric furnace, and the first A slag solidification step of cooling and solidifying the molten oxidized slag that has undergone the iron component separation step, a crushing step of crushing the solid oxidized slag solidified after the slag solidification step, and an iron-containing component contained in the slag particles crushed by the crushing step It is to prepare aggregate for asphalt pavement, including the step of separating the ferric constituents to be separated, and the reforming stabilization step to remove the expansion factors by modifying the slag particles undergoing the ferric ions separation step.
The present invention is to be able to reuse the oxidized slag which is a by-product generated during the operation of the electric furnace as asphalt aggregate, according to the present invention by replacing a part of the aggregate constituting the concrete composition with the oxidized slag with electricity, It has a useful effect of reducing costs and improving environmental problems.

Description

Manufacturing Method of Asphalt Pavement Aggregate Using Electrically Oxidized Slag {MANUFACTURING METHOD FOR ASPHALT PAVEMENT AGGREGATE USING ELECTRICFURNACE OXIDIZED SLAG}

The present invention relates to a method for producing asphalt pavement aggregates using oxidized slag with electricity, and more particularly, to invent asphalt pavement aggregates in which iron components in the oxidized slag are more efficiently removed.

In general, asphalt pavement is a type of road pavement that covers the surface of the road with an asphalt mixture.

The general structure of the asphalt pavement is composed of an asphalt surface layer and a base layer, and an upper layer subgrade and a lower layer subgrade.

The asphalt surface layer and base layer are heated and mixed with aggregate, filler material, asphalt and asphalt binder, and are evenly ground and packed into rollers on the upper layer subgrade.

In addition, since general aggregates such as natural sand or stone powder used in the asphalt pavement are collected in nature, the collection is limited because it causes destruction and environmental problems of the natural ecosystem during the collection.

On the other hand, slag (slag) generally refers to a solvent, a non-metallic substance, a metal oxide, etc., which floats or remains on waste water when melting iron ore or scrap in a furnace, an electric furnace, a cupola, or the like.

The slag floats on the surface of the molten steel during melting of the raw material, thereby preventing the molten steel surface from being oxidized by air and preserving the surface thereof.

The present invention is to provide a method for producing an aggregate for asphalt pavement using an electric oxidized slag to reduce the cost of the pavement by replacing the natural aggregate used in the pavement of the oxidized slag.

The object of the present invention is the first iron component separation step of separating the iron-containing components in the molten oxide slag discharged from the electric furnace;

A slag solidification step of cooling and solidifying the molten oxidized slag passed through the first iron component separation step;

A crushing step of crushing the solidified solid oxide slag after the slag solidification step;

A second iron component separation step of separating the iron-containing component contained in the slag particles crushed by the crushing step;

It is solved by providing a method for producing an aggregate for asphalt pavement aggregate using an electrically oxidized slag including a reforming stabilization step of reforming the slag particles subjected to the separation of the second iron component to remove expansion factors.

The first iron component separation step is characterized in that the iron-containing components contained in the molten oxidized slag stored in the slag port is removed by centrifugation.

The centrifugal separation process, the rotary rod member having a rotary blade disposed at the end into the slag port;

A rotary motor member for rotating the rotary rod member;

The rotary vane rotates in the molten oxidized slag stored into the slag port by using a centrifugal separator including a rod support member on which the rotary rod member is mounted to generate a vortex in the molten oxidized slag, and the centrifugal force by the rotary vortex As a result, the iron-containing component having a high specific gravity is lowered and removed along the inner wall of the slag port.

The second iron component separation step, and the belt member for transporting the slag particles placed on the upper portion in the circular orbital movement;

A first pulley member to which one end side of the belt member on which the slag particles are placed is wound;

A second pulley member having a magnet part on an outer circumferential surface of the other end side of the belt member in which the slag particles fall and fall;

A magnetic force generating unit arranged to be spaced apart from the upper portion of the belt member and separating the metal component of the slag particles transferred to the upper portion of the belt member by magnetic force;

A motor connected to either side of the first pulley member and the second pulley member;

A first support storage member disposed below the other end side of the belt member and receiving slag particles falling from the other end side of the belt member;

By using a magnetic separator including a second support storage member disposed on the lower side of the belt member spaced apart from the first support storage member and attached by the magnetic force of the magnet portion of the second pulley member to receive slag particles that fall down.

A first magnetic screening process of first removing a metal component to the magnetic force generating unit while transporting slag particles on the belt member;

After the first magnetic force screening process, the metal component remaining in the slag particles is attached to the belt member by the magnetic force of the magnet part of the second pulley member, and then the metal component is dropped to the second support storage member at the point where the magnetic force is weakened. It is characterized in that it comprises a second magnetic screening process to remove.

In the reforming stabilization step, free lime (CaOH ₂ ) and limestone (CaCO ₃ ) are reacted with water (H ₂ O) and carbon dioxide at high temperature to react with free lime (CaO 3), which is included in the oxidized slag, causing expansion. It is characterized by stabilizing.

In the reforming stabilization step, the slag particles are stored in the reaction tank, and then calcined exhaust gas and steam are introduced into the reaction tank through the exhaust gas supply pipe and the steam supply pipe to stabilize the reaction.

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The present invention is to be able to reuse the oxidized slag which is a by-product generated during the operation of the electric furnace as asphalt aggregate, according to the present invention by replacing a part of the aggregate constituting the concrete composition with the oxidized slag with electricity, It has a useful effect of reducing costs and improving environmental problems.

1 is a block diagram showing a method for producing an aggregate for asphalt pavement using the present inventors oxidized slag
Figure 2 is a schematic diagram showing the centrifuge used in the first iron component separation step of the present invention
Figure 3 is a schematic diagram showing a magnetic separator used in the separation step of the second iron component of the present invention
4 is a schematic diagram illustrating a reactor used in the reforming stabilization step of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Hereinafter, as shown in FIG. 1, the method for preparing aggregate for asphalt pavement using the present inventors' electric furnace oxidized slag is a first iron component separation step 100, a slag solidification step 110, a crushing step 120, and a second iron. Component separation step 130, the reforming stabilization step 140 is made sequentially to manufacture the asphalt pavement aggregate.

The first iron component separation step 100 is to separate the iron-containing components in the molten oxide slag discharged from the electric furnace to remove the iron-containing components contained in the molten oxide slag stored in the slag port 10a by centrifugation. .

The centrifugal separation process includes a rotary rod member 11 having a rotary blade portion 11a disposed at the end of the slag port 10a as shown in FIG. 2;

A rotary motor member 12 for rotating the rotary rod member 11;

The centrifugal separator 10 including the rod support member 13 on which the rotary rod member 11 is mounted is used.

In the centrifugal separation process, the rotary motor member 12 is operated to rotate the rotary rod member 11, thereby rotating the rotary blade part 11a to rotate the molten oxidized slag in the slag port 10a.

At this time, the molten slag generates centrifugal force due to the rotational vortex, and the iron-containing component having a high specific gravity moves toward the inner wall of the slag port 10a, and then descends along the wall to be collected at the lower portion of the slag port 10a, and compared with the iron-containing component. Other inclusion components having a small specific gravity move to the center and top of the slag port 10a.

 The centrifugation process is preferably carried out while the temperature of the molten oxidized slag maintains a temperature of 1000 ℃ or more.

This is because when the temperature of the molten oxidized slag falls below 1000 ° C., the molten slag gradually solidifies and the fluidity decreases, thereby making it difficult to rotate the rotary blade 11a.

After the first iron component separation step 100, the molten oxidized slag is subjected to a slag solidification step 110 for slow cooling and solidification through a sprinkling treatment in air.

The oxidized slag solidified in the slag solidification step 110 is crushed into slag particles having a particle size of 0.08 mm or more and 5.0 mm or less.

A particle size of 0.08 mm is the minimum particle size to be used as asphalt aggregate.

When the particle size exceeds 5.0 mm, the compoundability decreases and the probability of cracking greatly increases due to expansion caused by the hydration reaction of the glass lime.

Therefore, it is preferable to maintain the particle size of the slag particles crushed in the crushing step 120 to 0.08mm or more to 5.0mm or less.

After the crushing step 120, a second iron component separation step 130 for removing a metal component including iron in the crushed slag particles is performed.

The second iron component separation step 130 is to remove metal components including iron-containing components of the slag particles by magnetic force through the magnetic separator.

The magnetic separator 20 is a belt member (21) for transporting the slag particles (1) mounted on the upper side in the circular orbital movement as shown in Figure 3;

A first pulley member 22 to which one end side of the belt member 21 on which the slag particles 1 are placed is wound;

A second pulley member 23 having a magnet portion 23a on an outer circumferential surface of the belt member 21 on which the slag particle 1 falls and is wound;

A magnetic force generating part 24 disposed to be spaced apart from the upper portion of the belt member 21 to separate the metal component of the slag particles 1 transferred to the upper portion of the belt member 21 by magnetic force;

It includes a motor (not shown) connected to any one of the first pulley member 22 and the second pulley member 23.

In addition, the magnetic separator 20 may further include a scraper disposed in contact with the belt member 21 at the lower side of the belt member 21.

In addition, the magnetic separator 20 is disposed below the other end side of the belt member 21, the first support storage member 25 receives the slag particles (1) falling from the belt member 21 and the first 1 slag particles (1) which are disposed on the lower side of the belt member 21 to be spaced apart from the backing storage member 25 is attached by the magnetic force of the magnet portion 23a of the second pulley member 23 and then dropped It further comprises a second receiving storage member 26 receiving.

That is, the second iron component separation step 130 is primarily a metal to the magnetic force generating portion 24 while transporting the slag particles (1) crushed in the crushing step 120 on the belt member 21 and transported A first magnetic screening process for removing the components;

After the first magnetic force screening process, the metal component remaining in the slag particles is attached to the belt member 21 by the magnetic force of the magnet portion 23a of the second pulley member 23 and then the metal is weakened at the point where the magnetic force is weakened. And a second magnetic screening process for dropping and removing the component onto the second backing storage member 26.

In the separating of the second iron component 130, the metal component exposed to the upper portion of the slag particles 1 placed on the belt member 21 is attached to the magnetic force generator 24 to remove the first iron component. The slag particles (2) may be secondly removed through the magnet part 23a of the second pulley member 23 by laying down below the slag particles 1 and not being removed by the magnetic force generating part 24. It is to efficiently remove the metal component contained in 1).

In addition, the other slag particles 1 are dropped on the end side of the belt member 21 wound on the second pulley member 23 and stored in the first support storage member 25 to be finally sorted. It is moved to the reforming stabilization stage.

After the second iron component separation step 130, a reforming stabilization step 140 is performed to modify the selected slag particles 1 to remove expansion factors.

The reforming stabilization step 140 includes free lime (CaOH ₂ ) and limestone (CaCO ₃ ) by reacting glass lime (free-CaO), which is included in the oxide slag, with water (H ₂ O) and carbon dioxide at a high temperature to cause expansion. Change to stabilize.

In the reforming stabilization step 140, as shown in FIG. 4, the slag particles 1 are stored in the reaction tank 30 and then the calcined exhaust gas and steam are discharged through the exhaust gas supply pipe 31 and the steam supply pipe 32. 30) to stabilize the reaction by the addition, it can be represented by the following reaction formula 1.

A blower 31a is mounted in the exhaust gas supply pipe 31 to introduce the exhaust gas into the reactor 30.

[Reaction Scheme 1]

H ₂ O + CO ₂ → H ₂ CO ₃ → H ⁺ + HCO ^3- → 2H ⁺ + CO ₃ ^2-

CaO + H ₂ O → Ca (OH) ₂ + CO ₃ ^2-

_{Ca (OH) 2 + CO 3} 2- → CaCO 3 + 2OH -

In the reforming stabilization step 140, the slag particles 1 are injected into the closed reaction tank 30 in a reverse direction to the calcined exhaust gas containing carbon dioxide (CO ₂₎ and water vapor.

In addition, the concentration of carbon dioxide (CO ₂₎ in the calcined exhaust gas in the reactor 30 is preferably 17 to 20% by volume based on the total gas components in the reactor 30, and the temperature in the reactor 30 is preferably 60 to 80 ° C. Do.

The calcined flue gas may include a general gas component known in the art in addition to CO ₂ .

In addition, the residence time of the slag particles 1 in the reaction tank 30 is preferably about 65 to 80 minutes.

After the reforming stabilization step 140, the slag particles 1 in the reactor 30 are discharged through the discharge pipe 33.

On the other hand, the asphalt paving aggregate manufactured by the above method using the oxidized slag is 5 to 10% less iron-containing components compared to the general oxidized slag has a specific gravity is small, it is effective to reduce the amount of asphalt used in the asphalt paving.

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That is, the asphalt pavement aggregate and the asphalt aggregate are mixed in a weight ratio, but the specific gravity of the asphalt aggregate is small, so that the mixing amount of the asphalt aggregate can be relatively reduced.

In addition, the asphalt pavement aggregate of the present invention contains less iron components, there is no risk of corrosion during use and can maintain a stable state for a long time, there is also the effect of resource recycling to separate and recycle the iron components.

The low-force test (KS F 2337) for the plastic flow of the asphalt mixture by mixing the weight ratio of the asphalt material to 100 wt% of the asphalt concrete aggregate using the oxide slag of the present invention is as shown in Table 1 below, and the test method is known. Note that further details are omitted.

Asphalt material mixing ratio (wt%) Test Items Density (t / m3) Clearance rate (%) Saturation (%) Porosity (%) Stability (N) Flow value (0.01 cm) 5.50 3.062 23.24 70.2 6.92 9566 22 6.00 3.106 23.36 77.3 5.3 10585 23 6.50 3.11 22.4 87.5 2.81 9216 25 KS F 2337 (standard) - - 70-85 3 to 6 More than 5000 20 to 40

As a comparative example, the results of the low force test (KS F 2337) on the plastic flow of the asphalt mixture by mixing the weight ratio of the asphalt material to 100 wt% of the general natural asphalt pavement aggregate differently are as shown in Table 2 below. Is omitted.

Asphalt material mixing ratio (wt%) Test Items Density (t / m3) Clearance rate (%) Saturation (%) Porosity (%) Stability (N) Flow value (0.01 cm) 5.30 2.264 19.34 60.1 7.72 11721 35 5.80 2.319 18.1 72 5.07 11501 35 6.20 2.316 18.74 74.2 4.83 10973 42 KS F 2337 (standard) - - 70-85 3 to 6 More than 5000 20 to 40

Asphalt pavement aggregate using the oxidized slag of the present invention, as shown in Table 1 and Table 2, the stability is similar to that of the general natural asphalt aggregate, the flow value is significantly lower, it is confirmed that the overall physical properties of the asphalt pavement better.

 Asphalt pavement aggregate using the oxide slag of the present invention is to improve the durability of the asphalt pavement by increasing the overall physical properties, that is, the strength, as well as the economics of the asphalt cost.

The present invention is not limited to the above-described embodiments, and various changes can be made without departing from the gist of the present invention, which is understood to be included in the configuration of the present invention.

10 centrifugal separator 11 rotating rod member
12: rotary motor member 13: rod support member
20: magnetic separator 21: belt member
22: first pulley member 23: second pulley member
24: magnetic force generating unit 25: the first support storage member
26: second support storage member 30: reaction vessel
100: ferrous iron component separation step 110: slag solidification step
120: crushing step 130: separation of the second iron component
140: reforming stabilization step

Claims (7)

delete A first iron component separation step of separating the iron-containing component in the molten oxide slag discharged from the electric furnace;
A slag solidification step of cooling and solidifying the molten oxidized slag passed through the first iron component separation step;
A crushing step of crushing the solidified solid oxide slag after the slag solidification step;
A second iron component separation step of separating the iron-containing component contained in the slag particles crushed by the crushing step;
A reforming stabilization step of removing expansion factors by reforming the slag particles that have undergone the separation of the second iron component,
The first iron component separation step, the method for producing the aggregate for asphalt pavement using the electric furnace oxidized slag, characterized in that the iron-containing component contained in the molten oxidized slag stored in the slag port by centrifugation process. The method according to claim 2,
The centrifugal separation process, the rotary rod member having a rotary blade disposed at the end into the slag port;
A rotary motor member for rotating the rotary rod member;
The rotary vane rotates in the molten oxidized slag stored into the slag port by using a centrifugal separator including a rod support member on which the rotary rod member is mounted to generate a vortex in the molten oxidized slag, and the centrifugal force by the rotary vortex Method for producing an aggregate for asphalt pavement using an electric furnace oxidized slag characterized in that by removing the iron-containing components having a high specific gravity by lowering along the inner wall of the slag port. A first iron component separation step of separating the iron-containing component in the molten oxide slag discharged from the electric furnace;
A slag solidification step of cooling and solidifying the molten oxidized slag passed through the first iron component separation step;
A crushing step of crushing the solidified solid oxide slag after the slag solidification step;
A second iron component separation step of separating the iron-containing component contained in the slag particles crushed by the crushing step;
A reforming stabilization step of removing expansion factors by reforming the slag particles that have undergone the separation of the second iron component,
The second iron component separation step, and the belt member for transporting the slag particles placed on the upper portion in the circular orbital movement;
A first pulley member to which one end side of the belt member on which the slag particles are placed is wound;
A second pulley member having a magnet part on an outer circumferential surface of the other end side of the belt member in which the slag particles fall and fall;
A magnetic force generating unit arranged to be spaced apart from the upper portion of the belt member and separating the metal component of the slag particles transferred to the upper portion of the belt member by magnetic force;
A motor connected to either side of the first pulley member and the second pulley member;
A first support storage member disposed below the other end side of the belt member and receiving slag particles falling from the other end side of the belt member;
By using a magnetic separator including a second support storage member disposed on the lower side of the belt member spaced apart from the first support storage member and attached by the magnetic force of the magnet portion of the second pulley member to receive slag particles that fall down.
A first magnetic screening process of first removing a metal component to the magnetic force generating unit while raising and transporting slag particles on the belt member;
After the first magnetic force screening process, the metal component remaining in the slag particles is attached to the belt member by the magnetic force of the magnet part of the second pulley member, and then the metal component is dropped to the second support storage member at the point where the magnetic force is weakened. Method for producing an aggregate for asphalt pavement using an electric furnace oxidized slag, characterized in that it comprises a second magnetic screening process to remove by. The method according to claim 2 or 4,
In the reforming stabilization step, free lime (CaOH ₂ ) and limestone (CaCO ₃ ) are reacted with water (H ₂ O) and carbon dioxide at high temperature to react with free lime (CaO 3), which is included in the oxidized slag, causing expansion. Method for producing aggregate for asphalt pavement using the electric furnace oxidized slag, characterized in that stabilization. The method according to claim 2 or 4,
The reforming stabilization step, after storing the slag particles in the reaction tank and the production method of the asphalt pavement aggregate using the electric furnace oxidized slag characterized in that the stabilization reaction by adding the calcined exhaust gas and steam into the reaction tank through the exhaust gas supply pipe and steam supply pipe. delete

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