JP2003200131A - Method for recycling end-of-life vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To recycle an end-of-life vehicle (ELV) as an iron resource without shredding it, or without producing shredder dust. <P>SOLUTION: When cubic waste car press scraps 15 obtained from the ELV without shredding are melted together with municipal scraps 16 with the use of a melting apparatus having a melting chamber 2 and a preliminary heating chamber 3 connected directly to the melting chamber, the car press scraps with the total length L of three sides of at least 1,300 mm are used. The mixing ratio R of the car scraps in relation to the removal rate X of combustible members from the car meets formula (1) of R≤0.6X+30, and the ratio R in relation to the total length L meets formula (2) of R≤-(1/30)L+120. The car scraps and the municipal scraps are melted while being supplied to the preliminary heating chamber so that the car scraps are kept unmelted in the melting chamber and the preliminary heating chamber and discharged when a prescribed amount of molten metal 17 is produced. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recycling used automobiles, and more particularly to a method for recycling used automobiles as an iron source without shredding.

[0002]

2. Description of the Related Art Conventionally, used automobiles are pressed after removing valuable parts such as batteries, engines and tires, shredded after pressing and reused as iron scraps. During this shredder treatment, shredder dust containing plastic, rubber, iron, aluminum, copper, etc. is generated. About 1 ton of used car 1
About 200 kg of shredder dust is generated by shredder processing, and about 800,000 tons of shredder dust is generated annually from used automobiles in Japan. This shredder dust is either landfilled or burned and melted in a waste incinerator.

The landfill disposal requires a large amount of disposal cost because the disposal site is limited, and in the combustion treatment by the incinerator, the ash content and the metal content in the shredder dust remain, and this disposal becomes a problem. Further, in the method of directly gasifying the shredder dust and directly melting the incombustible content, a molten metal containing iron and copper as main components is produced, and this is used as a counterweight after solidification, but the amount used is limited. Yes, the disposal of this bullion becomes a problem.

On the other hand, used automobiles (hereinafter also referred to as "waste cars") are not shredded, and used automobile scraps (hereinafter referred to as "waste car press scraps") are directly processed in a steelmaking melting furnace typified by a converter. The dissolution method is disclosed in JP-A-10-33.
It is proposed in Japanese Patent No. 0821. According to this method
No shredder dust is generated, and plastic, rubber, etc. also serve as a heat source during melting, and scrap car scraps can be efficiently melted. However, this method has a limit to the amount of scrap scraps that can be dissolved. That is, according to the same publication, the amount of scrap scraps of scrap cars that can be loaded into a 250 ton converter can be up to 15 tons (heat scrap: about 10 cars) per heat because of the steel composition. Due to problems such as the method of charging scrap into the furnace and smoke generation during charging, the limit is actually about four scrap cars per heat.

Although it is naturally conceivable to directly load scrap scraps into an arc melting facility (electric furnace), scrap scraps are large in size (about 0.7 m × 0.7 m × 1.0 m). In addition, since the bulk density is small, the furnace lid must be opened and closed every time a scrap car press is loaded in an ordinary arc melting facility. There is naturally a limit to the charging.

[0006]

DISCLOSURE OF THE INVENTION The number of scrapped vehicles generated in Japan is about 5 million a year, and as described above, such a large number of used vehicles can be shredded without being shredded with the conventional technology. , It is impossible to recycle in a converter or arc melting equipment which is a typical steelmaking melting furnace.

The present invention has been made in view of the above circumstances,
It is an object of the present invention to provide a method for recycling a large amount of used automobiles as an iron source without shredding, that is, without producing shredder dust.

[0008]

The inventors of the present invention have previously proposed means for solving the above-mentioned problems (Japanese Patent Application No. 2001-843).
57). The proposed recycling treatment method uses a melting facility that has a melting chamber having a heating source and a shaft-type preheating chamber that is directly connected to this melting chamber and preheats by the exhaust gas generated in the melting chamber. When melting scrap car press scraps obtained without treatment, continuously dispose of scrap car press scraps into the preheating chamber so that unmelted scrap car press scraps remain in the melting chamber and preheating chamber continuously. Alternatively, the scrap car press waste in the melting chamber is melted by the heating source while being intermittently supplied, and is discharged when a predetermined amount of molten metal is generated in the melting chamber.

However, it was found from the results of the subsequent examination that the proposed recycling method also has the following problems. That is, when the mixing ratio R of scrap car press scraps is increased, a hanging phenomenon occurs in the preheating chamber depending on the size of scrap car press scraps, and the scrap car press scraps may not be stably lowered downward. In order to solve this problem, if the compression force at the time of press molding is increased, the size of scrap car press scraps is reduced, and the blending ratio R is increased, the density of scrap car press scraps is increased, and scrap car press scraps are increased. It becomes difficult to melt itself, so that a phenomenon occurs that time is taken for melting.

If the compounding ratio R of scrap car press waste is high,
Combustible materials such as plastic and rubber in scraps of scrap car presses (1
A large amount of exhaust gas is generated from a unit (4000 kcal / kg x about 200 kg / 1 unit), and there is a problem in that not only the exhaust gas suction facility, but also the secondary combustion facility for the exhaust gas and the cooling facility are indispensable.

Further, when the size of scrap car press waste is large,
When charging into the preheating chamber at a constant mixing ratio R and charging interval,
Since the number of scrap car press scraps that can be put in at one time is limited, it is necessary to set the upper limit of the size of scrap car press scraps also from this point.

In order to solve these problems, various tests were carried out by changing the size of scrap car press waste, the compounding ratio R of scrap car press scrap, and the removal rate X of combustible members from scrap cars, and investigating the effects thereof. did. The size of the scraps of scraps of pressed cars is evaluated by the sum L (mm) of the lengths of the three sides of the scraps of scraps of pressed cars, which have a rectangular parallelepiped shape. In addition, the scraps of scrapped car press were melted together with general industrial scrap.

As a result, from the test in which the size of the scrap car press scrap was changed, in order to quickly dissolve the scrap car press scrap itself, the sum L (mm) of the three sides of the scrap car press scrap was 130.
The finding that 0 mm or more is necessary was obtained. If the sum L of the three sides is less than 1300 mm, it is necessary to increase the compressive force during press molding, so that the bulk density of scrap scrap of scrapped vehicles increases, and it can be confirmed that the melting rate extremely decreases. It was

Further, from the results of investigating the amount of exhaust gas generated by changing the removal rate X of the combustible member and changing the mixing ratio R of the scrap car press scrap, the mixing ratio R (mass%) of the scrap car press scrap is It was found that it is necessary to satisfy the following expression (1) for the removal rate X (mass%) of the combustible member. When the compounding ratio R (mass%) of scrap car press scrap does not satisfy the following formula (1), the amount of gas generated from scrap car press scrap is large, and the exhaust gas treatment system of an ordinary electric furnace cannot cope with it. It was confirmed that this would lead to a significant increase in costs. Here, the removal rate X (mass%) is a value in which the mass obtained by removing the combustible members such as plastic and rubber from the scrap car before pressing is expressed as a percentage with respect to the mass of the combustible members attached to the scrap car. .

[0015]

[Equation 1]

Further, from the test of investigating the descendability of the scrap car press scraps in the preheating chamber by changing the size of the scrap car press scraps and changing the mixing ratio R of the scrap car press scraps, the mixing ratio R ( It has been found that mass%) needs to satisfy the following expression (2) with respect to the sum L (mm) of the lengths of the three sides of scrap car press waste. It was confirmed that if the mixing ratio R (mass%) of scrap car press scrap does not satisfy the following expression (2), hanging in the preheating chamber occurs. In addition, from the formula (2), the upper limit of the size of scrap car press waste is
It can be seen that the sum L of the lengths of the three sides is 3600 mm or less.

[0017]

[Equation 2]

The present invention was made on the basis of the above findings. The method for recycling used automobiles according to the first invention is a melting chamber having a heating source and a melting chamber directly connected to the melting chamber and generated in the melting chamber. Using a melting facility that has a shaft-type preheating chamber that preheats with exhaust gas, a rectangular parallelepiped-shaped scrap car press scrap obtained from a used car without shredding is melted together with a city scrap. In the recycling method, the scrap car press scrap whose sum L of the three sides is 1300 mm or more is used, and the compounding ratio R (mass%) of the scrap car press scrap is defined as the removal rate X of the combustible member from the scrap car. (Mass%) within the range of the above formula (1) and within the range of the above formula (2) with respect to the above sum L (mm), and the state in which scrap car press scraps or commercial scraps are not melted so While supplying the scrap car press scraps and city scraps to the preheating chamber so as to maintain the state existing in the thaw chamber and the preheating chamber, the scrap car press scraps and city scraps in the melting chamber are melted by the heating source, and are then melted in the melting chamber. The method for recycling a used automobile according to the second invention is characterized in that the heating source is arc heating in the first invention, characterized in that the molten metal is discharged when a predetermined amount of molten metal is produced. Is.

According to the first aspect of the present invention, since the size of the scrap car press scrap is proper, and the compounding ratio R of the scrap car press scrap is set according to the size of the scrap car press scrap and the removal rate X of the combustible member, Dissolution delay of scrap car press scrap itself can be resolved, hanging on the shelf in the preheating chamber can be prevented, and the amount of exhaust gas generated is suppressed. It is also possible to deal with the usual electric furnace. Further, in the second invention, since arc heating is used as the heating source, the amount of heating and the heating rate can be easily controlled, and scraps of scrapped car press can be quickly and stably melted.

In the present invention, scrap car press waste is used after removal of valuable parts such as batteries, engines and tires, part of plastics such as bumpers, and parts of copper-containing members such as harnesses and motors. It is a pressed car.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic vertical cross-sectional view of an arc melting equipment used when carrying out a recycling process of a used automobile according to the present invention, and FIG. 2 is a schematic plan view of the arc melting equipment shown in FIG.

In FIGS. 1 and 2, a shaft type preheating chamber 3 and a water-cooled furnace wall 4 are provided at the upper part of the melting chamber 2 which is constructed of a refractory material and has a furnace bottom electrode 6 at the bottom. The upper opening of the furnace wall 4 which is arranged is covered with a furnace lid 5 having a water-cooling structure that can be opened and closed. An upper electrode 7 made of graphite is provided which penetrates through the furnace lid 5 and is vertically movable into the melting chamber 2. DC power supply (not shown) for the furnace bottom electrode 6 and the upper electrode 7
And an arc 19 serving as a heating source is generated between the furnace bottom electrode 6 and the upper electrode 7.

Above the preheating chamber 3, a bottom open type supply bucket 14 for supplying scrap car press waste 15 and commercial scrap 16 obtained without performing shredder treatment as a melting iron source is a traveling carriage. The opening / closing lid 20 and the opening / closing lid 20a provided on the upper portion of the preheating chamber 3 are opened and closed by the supply bucket 14 to melt the scraps 15 of scrapped cars and the scraps 16 in the city. It is loaded into the preheating chamber 3 as an iron source. When loading these melting iron sources, the opening / closing lid 20 and the opening / closing lid 20a are alternately opened / closed, that is, one of the opening / closing lids 20 and 2 is opened.
By closing 0a, leakage of exhaust gas generated in the melting chamber 2 can be prevented.

As the iron source for melting, as described above, the scrap car press scrap 15 obtained from the used automobile without shredding treatment and the general commercial scrap 16 are mixed and used at a certain ratio. To do. However, in addition to these, other cold iron sources such as cold pig iron and direct reduced iron may be used instead of the commercial scrap 16. Also, used scrap car press waste 15
Has a sum L of its three sides of 1300 mm to 3600 m.
m.

A large number of copper members are arranged as conductive materials in automobiles. Since these copper members are the main cause of increasing the copper concentration of the molten metal 17 after melting, the copper members are removed from the used automobile in advance. After that, it may be scrapped.
At that time, 80 mass% of the copper members that compose the automobile
By removing the above in advance, the copper concentration of the molten metal 17 to be produced can be suppressed to 0.35 mass% or less, and the iron content of steel products with a copper concentration standard of about 0.35 mass% or less without mixing with blast furnace hot metal. Can be used as a source. However,
If the compounding ratio R of the scrap car press waste 15 is low, it is diluted with the city scrap 16, and in that case, it is not necessary to remove it.

A duct 21 connected to a dust collector (not shown) is provided above the preheating chamber 3, and high-temperature exhaust gas generated in the melting chamber 2 is discharged through the preheating chamber 3 and the duct 21. It At that time, the exhaust gas passing through the preheating chamber 3 preheats the scrap car press waste 15 and the city scrap 16 loaded in the preheating chamber 3.

A pusher 11 is installed below the preheating chamber 3. The pusher 11 goes in and out of the preheating chamber 3,
A melting iron source consisting of scrap car press scrap 15 and city scrap 16 filled in the preheating chamber 3 is pushed into the melting chamber 2 and supplied. If the pusher 11 frequently moves in and out of the preheating chamber 3, a large amount of the melting iron source is supplied to the melting chamber 2, and if the pusher 11 is stopped, the melting iron source melts in the melting chamber 2. According to the amount of the iron source for melting to be melted, it falls freely into the melting chamber 2 and is charged into the melting chamber 2. However, in this case, the amount of the iron source for melting supplied to the melting chamber 2 is not stable, and in the preheating chamber 3, it may be suspended and the supply may be stagnant.

An oxygen blowing lance 8 and a carbonaceous material blowing lance 9 which can move up and down in the melting chamber 2 through the furnace lid 5 are provided, and oxygen is blown into the melting chamber 2 from the oxygen blowing lance 8. From the carbon material blowing lance 9, air, nitrogen, etc. are used as a carrier gas for coke, char,
Carbon materials such as coal, charcoal, graphite, etc. are blown into the melting chamber 2.

The protruding portion 2a provided on a portion of the melting chamber 2 different from the side to which the preheating chamber 3 is directly connected has a bottom portion, the outlet side of which is pressed by a door 22 so that sand or mud is filled inside. A tap hole 12 filled with the agent and a slag hole 13 whose side wall is filled with sand or mud agent and whose outlet side is pressed by a door 23 are provided. A burner 10 is attached to the furnace lid 5 at a portion corresponding to the vertically upper side of the tap hole 12. Burner 10
Burns fossil fuels such as heavy oil, kerosene, pulverized coal, propane gas, and natural gas in the melting chamber 2 with air or oxygen or oxygen-enriched air. The melting chamber 2 is tilted toward the tap hole 12 side by a tilting device (not shown). In this way, the DC arc melting equipment 1 is constructed.

DC arc melting equipment 1 having such a structure
Car scraps obtained from used cars in
When recycling is carried out using iron as an iron source, first, the blending ratio R of the scrap car press waste 15 is set based on the equations (1) and (2). Incidentally, in FIG. 3, the range of the compounding ratio R of the scrap car press waste 15 when the removal rate X of the combustible member from the scrap car is 12.5 mass% is shown by the diagonal lines, and the scrap car press scrap is made to fall within this range. The blending ratio R is determined according to the size of 15. For example, when the sum L of the lengths of three sides is 1500 mm, the upper limit of the compounding ratio R is (1)
When the sum L of the lengths of the three sides is 2700 mm as defined by the formula and the sum L of the three sides is 2700 mm, the upper limit of the compounding ratio R is 30 mass% as defined by the formula (2).

Then, the melting chamber 2 is set in a horizontal state, and the scrap car press scrap 15 and the city scrap 16 are fed from the supply bucket 14 into the preheating chamber 3 so that the mixing ratio R of the scrap car press scrap 15 is within the set range. Charge. These iron sources for melting are also charged into the melting chamber 2 via the preheating chamber 3 and eventually fill the inside of the preheating chamber 3. Incidentally, in order to uniformly load these melting iron sources into the melting chamber 2, the furnace lid 5 may be opened and the melting source 2 may be directly charged into the melting chamber 2 opposite to the preheating chamber 3. Further, as described above, another cold iron source such as cold pig iron or direct reduced iron may be simultaneously charged into the preheating chamber 3 or the melting chamber 2 as a melting iron source.

Then, the upper electrode 7 is moved up and down while supplying a direct current between the furnace bottom electrode 6 and the upper electrode 7, and the space between the furnace bottom electrode 6 and the upper electrode 7 or the scrap car press loaded. An arc 19 is generated between the scrap 15 and the city scrap 16 and the upper electrode 7. Then, the generated arc heat melts these melting iron sources to generate the molten metal 17.
Along with the formation of the molten metal 17, flux such as quick lime and fluorite is charged into the melting chamber 2 to form the molten slag 18 on the molten metal 17 to prevent the molten metal 17 from being oxidized and to keep the molten metal 17 warm. When the amount of the molten slag 18 is too large, the molten slag 18 can be discharged from the outlet 13 even during melting.

As the molten metal 17 is formed, the scraps 15 of scrapped cars and the scraps 16 in the market in the melting chamber 2 are reduced.
From the time when the molten metal 17 is generated in the melting chamber 2, the pusher 11
Start driving. The pusher 11 may be operated to reciprocate within the preheating chamber 3 in about 10 seconds at intervals of several minutes, for example, once every 3 minutes. The iron source for melting filled in the preheating chamber 3 is forcedly pushed by the pusher 11 and supplied to the molten metal 17 side.

The iron source for melting in the preheating chamber 3 is the molten metal 17
The amount of waste car press waste 15 and the city scrap 16 are charged from the supply bucket 14 to the preheating chamber 3 in order to compensate for this decrease. When the iron source for melting is charged into the preheating chamber 3, the iron source for melting is charged into the preheating chamber 3 and the melting chamber 2.
It is carried out continuously or intermittently so as to maintain the state of continuously existing in and. In this case, the compounding ratio R of the scrap car press waste 15
Blend so as not to exceed the upper limit set by.

From the time when the molten metal 17 is produced, it is preferable to blow oxygen from the oxygen blowing lance 8 and carbon material from the carbon material blowing lance 9 into the molten metal 17 or the molten slag 18 in the melting chamber 2. The carbonaceous material blown in and melted in the molten metal 17 or the carbonaceous material suspended in the molten slag 18 reacts with the blown oxygen to generate combustion heat and acts as an auxiliary heat source to save power consumption. At the same time, the CO gas of the reaction product forms the molten slag 18, and the arc 19 is surrounded by the molten slag 18, which is a so-called slag forming operation, so that the heat generation efficiency of the arc 19 increases.

Further, a large amount of high-temperature CO gas generated by blowing oxygen and carbonaceous material and CO ₂ gas produced by combustion of this CO gas are discharged through the preheating chamber 3 and the duct 21. To be done. The melting iron source in the preheating chamber 3 is efficiently preheated by this exhaust gas. The amount of carbon material blown in is determined according to the amount of oxygen blown in. That is, at least carbon material equivalent to the chemical equivalent of oxygen to be blown is blown. It is not preferable that the amount of carbon material blown in is chemically equivalent to the amount of blown oxygen, because the molten metal 17 is excessively oxidized.

Waste car press waste 15 and city scrap 16
Melt progresses, and a predetermined amount, for example, 1 heat of molten metal 17
When is accumulated in the melting chamber 2, the melting chamber 2 is tilted toward the tap hole 12 side, the door 22 that closes the tap hole 12 is opened, and the melt holding container 17 for one heat from the tap port 12 ( Hot water (not shown). When tapping hot water, melt 17
The molten metal 17 may be heated by the burner 10 in order to prevent the molten metal outlet 12 from being blocked due to the solidification of the molten metal. It should be noted that the predetermined amount of molten metal in the present invention means, for example, the amount of molten metal for one heat, or in the case of leaving the molten metal 17 in the melting chamber 2 after tapping, the amount of molten metal for one heat and the amount of molten metal in the melting chamber 2 It is an amount including the amount of residual molten metal, and is an amount of molten metal that is appropriately determined depending on the operating conditions.

When the molten metal 17 has a high copper concentration and needs to be mixed with the blast furnace hot metal and refined in a refining furnace such as a converter, the higher the carbon concentration of the molten metal 17 is, the converter refining in the next step is performed. Therefore, it is preferable that the carbon concentration of the molten metal 17 is increased and the molten metal 17 is discharged as hot metal. Molten metal 17
The carbon concentration of can be adjusted to an arbitrary value by controlling the amount of carbon material blown from the carbon material blowing lance 9. In this case, the carbon concentration may be adjusted as necessary before tapping. Then, after tapping, it is mixed with blast furnace hot metal, refined in a refining furnace such as a converter, melted into molten steel having predetermined components, and then cast by a continuous casting machine or the like. In this case, the blending amount of the molten metal 17 is adjusted so that the molten steel component after refining in the refining furnace conforms to the standard of copper concentration of steel products.

When refining in a refining furnace such as a converter, the molten metal 17 may be charged into the refining furnace as it is, or the molten metal 17 may be once solidified and then charged into the refining furnace. But good.
When the molten metal 17 is charged as it is, it may be mixed with the blast furnace hot metal and then charged into the refining furnace, or may be charged individually and mixed in the refining furnace.

On the other hand, when the copper member in the used automobile is removed or when a large amount of the city scrap 16 and the like are mixed, the copper concentration in the generated molten metal 17 becomes low,
No need to mix with blast furnace hot metal. When it is not necessary to mix the molten metal 17 with the blast furnace hot metal as described above, the chemical components such as the carbon concentration of the molten metal 17 are adjusted to the standard range of the intended steel product before the molten metal is discharged, or the ladle is discharged after the molten metal is discharged. If it can be refined in a smelting furnace, etc., it will be adjusted to a temperature close to the standard range and tapped, and then in a ladle smelting furnace, etc. adjusted to the standard range of steel products and cast by a continuous casting machine.

After the molten metal 17 is discharged, and the molten slag 18 is discharged as required, the melting chamber 2 is returned to the horizontal position, and the filling holes 12 and 13 are filled with filling sand or mud material. , Next, start melting the heat.

At the time of tapping, it is possible to maintain a state in which undissolved scrap car press scraps 15 or city scrap 16 are continuously present in the preheating chamber 3 and the melting chamber 2, and the preheating chamber 3 and the melting chamber are also kept. It is also possible to melt all the scrap car press scraps 15 and the city scrap 16 in 2 before tapping. When the scrap car press scrap 15 or the city scrap 16 is left in the preheating chamber 3 and the melting chamber 2, it is possible to preheat all the melting iron sources that melt after the second heat, and the power consumption is reduced. On the other hand, when the iron source for melting is completely melted for each tap, the temperature of the melt 17 during tapping can be adjusted arbitrarily, so that troubles when tapping due to the decrease in melt temperature can be solved. (Blockage of the tap hole 12, etc.) can be prevented.

When the state in which unmelted waste car press scraps 15 or city scraps 16 are continuously present in the preheating chamber 3 and the melting chamber 2 at the time of tapping, the molten metal 1
Since these iron sources for dissolution are buried in 7 and coexist,
The molten metal temperature is close to the solidification temperature, and it is difficult to obtain a sufficient degree of superheat. Therefore, when the molten metal temperature at the time of tapping is raised, when a predetermined amount, for example, one heat of the molten metal 17 is accumulated in the melting chamber 2, the operation of the pusher 11 is stopped and the melting iron source melting chamber 2 is operated. Arc heating or arc heating and the combined use of the burner 10 with a reduced supply of gas, or arc heating or arc heating with the melting chamber 2 tilted to the tap 12 side after the pusher 11 is stopped. It is preferable to heat by using together with the burner 10. By doing so, the melting iron source buried in the molten metal 17 is reduced, the contact area between the molten metal 17 and the melting iron source is reduced, and the amount of heating energy that contributes to the temperature rise of the molten metal 17 is increased. Therefore, the molten metal 17 having a large degree of superheat can be obtained.

By melting the scrap car press waste 15 as an iron source for melting in this way, the used automobile can be recycled without being shredded, that is, the used automobile can be produced without generating shredder dust. It can be recycled as an iron source. Further, the scrap car press scraps 15 are not directly charged into the molten metal 17, but are placed on the unmelted scrap car press scraps 15 and the city scrap 16 filling the preheating chamber 3 and are preheated in the preheating chamber 3. Since it is supplied to the molten metal 17 after being melted, volatilization and combustion of the combustible material contained in the scrap car press waste 15 gradually progresses during preheating, and it is necessary to prevent rapid combustion and smoke generation when immersed in the molten metal 17. You can

Furthermore, since the size of the scrap car press waste 15 and the mixing ratio R are set within appropriate ranges, there are problems of hanging in the preheating chamber 3 and problems of delay in melting the scrap car press scrap 15, The problems of increasing the capacity of the exhaust gas treatment facility and the problems of charging the preheating chamber 3 are all solved, and the scrap scrap 15 of the scrap car can be stably melted.

In the above description, the case of the DC type arc melting equipment is explained, but the present invention can be applied to the AC type arc melting equipment without any trouble. Further, the positional relationship between the preheating chamber 3 and the tap hole 12 in the melting chamber 2 is not limited to a position facing the center of the melting chamber 2 by 180 °, but may be a position of 90 °. Also, when tapping
The molten metal 17 of several tons to several tens of tons may be left in the melting chamber 2 and the melting of the next heat may be restarted. By doing so, the initial dissolution is promoted and the dissolution efficiency is improved. Further, although the case of arc heating as the heating source has been described, gas burner heating, electric induction heating, plasma gas heating or the like can be used as a heating source other than arc heating.

[0047]

EXAMPLES Example 1 In the DC arc melting equipment shown in FIG. 1, copper members such as motors and wirings were removed from a used automobile, and 30 mass% of combustible members such as tires and bumpers were removed. Scrap car press scraps that were pressed after being crushed (width: 500 mm, height: 600 mm, length:
An example using 700 mm) will be described below. The arc melting equipment used had a melting chamber with a furnace diameter of 7.2 m and a height of 4
m, the maximum width of the preheating chamber was 3 m, the length was 5 m, the height was 7 m, the furnace capacity was 180 tons, and about 80 mass% was removed from the copper members constituting the used automobile.

In this case, the sum L of the lengths of the three sides of the scraps of the scrapped car press is 1800 mm, and the removal rate X of the combustible member is 30 mass%.
Therefore, the upper limit value of the compounding ratio R of scrap car press waste is determined by the above-mentioned formula (1), and the upper limit value is 48 mass%. Therefore, in this embodiment, the compounding ratio R of scrap scrap of the scrap car is set to 20 mass%.

First, the compounding ratio R of scrap car press waste is 20 ma.
80 tons of scrap car press scraps and city scraps as a melting iron source were charged into the melting chamber and preheating chamber while adjusting the blending with the city scrap to be ss%, and a graphite upper electrode with a diameter of 30 inches was used. 750V, 130kA max.
The dissolution was started by the power capacity of. The pusher was moved in and out of the preheating chamber at intervals of 3 minutes as the molten metal was generated. or,
With the formation of the molten metal, quicklime and fluorite are added to form molten slag, and then oxygen is blown from the oxygen blowing lance at about 1500 Nm ³ / hr and coke from the carbonaceous blowing lance at about 20 kg / min. It was blown into the molten slag. The molten slag was formed by blowing oxygen and coke, and the tip of the upper electrode was embedded in the molten slag. The voltage at this time was set to 450V.

After that, as the scrap car press scraps and the city scraps in the melting chamber melt, when the scrap car press scraps and the city scraps in the preheating chamber descend, the scrap car press scraps (width: 500 mm, height) with the copper member removed : 600m
m, length: 700 mm) and commercial scrap are loaded into the preheating chamber with a supply bucket so that the scrap car press scrap mixing ratio R is 20 mass%, and scrap car press scrap and commercial scrap in the preheating chamber While the height of the filling material of and was kept constant, the dissolution was continued. And about 1 in the melting chamber
At the time when 60 tons of molten metal was generated, the operation of the pusher and the blowing of carbonaceous material were stopped, and only oxygen was blown into it to obtain molten steel with a predetermined carbon concentration. Remaining, about 120 tons of molten steel with a copper concentration of 0.28% and a carbon concentration of 0.2% is tapped in a ladle with scrap car press scraps and city scraps continuously present in the melting chamber and the preheating chamber. did. After tapping, it was cast into a billet slab of 150 mm square by a billet continuous casting machine.

As a result of repeating this operation, the hanging in the preheating chamber did not occur at all, and the scrap scraps of the scrap car could be stably melted, that is, it could be recycled as the iron source. Further, the amount of exhaust gas generated from scraps of scrap car press was small, and it was possible to deal with the problem with conventional exhaust gas treatment equipment.

Example 2 Using the same equipment as in Example 1, after removing copper members such as motors and wirings from a used automobile, and further removing 30 mass% of combustible members such as tires and bumpers. Pressed scraps of scrap cars (width: 500 mm, height: 600 mm, length: 700 m
32% of m) was blended and the same dissolution as in Example 1 was performed. In this case, the sum L of the three sides of scrap car press waste is 18
Since the removal rate X of the combustible member is 00 mm and the removal rate X is 30 mass%, the upper limit value of the compounding ratio R of scrap car press waste is the same as the above (1).
It is determined by the formula and the upper limit value is 48 mass%.

As a result of melting several heats, hanging in the preheating chamber did not occur at all, and scrap scraps of the scrap car could be stably melted, that is, recycled as an iron source. In addition, the amount of exhaust gas generated from scrap car press scrap is small,
It was possible to deal with it with the conventional exhaust gas treatment equipment.

[Embodiment 3] Using the same equipment as in Embodiment 1, after removing copper members such as motors and wirings from a used automobile and further removing 30 mass% of combustible members such as tires and bumpers. Pressed scraps of scrap cars (width: 700 mm, height: 750 mm, length: 1100
mm) was blended in an amount of 15% and the same dissolution as in Example 1 was performed. In this case, the sum L of the three sides of scrap car press waste is 2
At 550 mm, the removal rate X of the combustible member is 30 mass%. Therefore, the upper limit value of the compounding ratio R of scrap car press scraps is determined by the above-mentioned formula (2), and the upper limit value is 35 mass%.

As a result of melting several heats, hanging in the preheating chamber did not occur at all, and scrap scraps of the scrap car could be stably melted, that is, recycled as an iron source. In addition, the amount of exhaust gas generated from scrap car press scrap is small,
It was possible to deal with it with the conventional exhaust gas treatment equipment.

[Comparative Example 1] The size of scraps of scrap car presses is changed to the width:
900mm, height: 1000mm, length: 1250mm
Except for the above, the same equipment as in Example 1 was used under the same conditions as in Example 1, and the scraps of the scrapped car press were melted. In this case, hanging in the preheating chamber occurred during melting, and hanging for a maximum of 7 minutes did not occur.

Comparative Example 2 Using the same equipment as in Example 1, after removing copper members such as motors and wirings from a used automobile, and further removing 30 mass% of combustible members such as tires and bumpers. Pressed scrap of scrap car (width: 800 mm, height: 850 mm, length: 1200
mm) was blended in an amount of 30% and the same melting as in Example 1 was performed, but in this case, hanging in the preheating chamber occurred during melting, and hanging for 5 minutes at maximum did not disappear. .

[Comparative Example 3] The size of scraps of scrapped car presses varies according to width:
Using the same equipment as in Example 1 except that the height was 400 mm, the height was 400 mm, and the length was 450 mm, scraps of scrapped vehicle press were melted. In this case, it takes time to melt the scrap car press scrap itself, and it is confirmed that the scrap car press scrap floats on the molten metal surface in the melting chamber, which may hinder the supply of the melting iron source from the preheating chamber. there were.

[Comparative Example 4] Using the same equipment as in Example 1, after removing copper members such as motors and wirings from a used automobile and further removing 5 mass% of combustible members such as tires and bumpers. Pressed scraps of scrap cars (width: 500 mm, height: 600 mm, length: 700 m
Although 35% of m) was blended and the same dissolution as in Example 1 was carried out, in this case, the amount of exhaust gas generated from scraps of scrap cars was large, and it was not possible to cope with it with an exhaust gas treatment facility.

[0060]

According to the present invention, a large amount of used automobiles can be recycled as an iron source without being shredded, in other words, no shredder treatment cost and shredder dust treatment cost are required, and used automobiles can be recycled. Can be recycled as an iron source at low cost, resulting in a special effect in industry.

[Brief description of drawings]

FIG. 1 is a schematic vertical cross-sectional view of an arc melting facility used when carrying out the present invention.

FIG. 2 is a schematic plan view of the arc melting equipment shown in FIG.

FIG. 3 is a diagram showing a range of a compounding ratio R of scrap scrap of scrapped vehicle when a removal rate X of a combustible member is 12.5 mass%.

[Explanation of symbols]

1 DC arc melting equipment 2 Melting chamber 3 preheating room 6 Furnace bottom electrode 7 Upper electrode 8 oxygen blowing lance 9 Charcoal blowing lance 11 pushers 12 Outlet 13 Debris mouth 14 Supply bucket 15 scrap car press scrap 16 City scrap 17 Molten metal 18 Molten slag 19 arc

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F27D 13/00 B09B 3/00 303A ZAB F term (reference) 4D004 AA21 AA26 AC04 BA05 CA29 CB04 CB15 CB31 CB34 CC01 DA03 DA20 4K001 AA10 BA22 CA09 FA10 GA01 GA16 GB01 GB02 GB03 4K014 CB01 CB07 CB09 CC01 CC04 CD02 CD13 CD14 4K063 AA04 AA12 AA13 BA13 CA07 GA02 GA09

Claims (2)

[Claims] 1. A shredder process is performed from a used automobile by using a melting facility having a melting chamber having a heating source and a shaft type preheating chamber directly connected to the melting chamber and preheated by exhaust gas generated in the melting chamber. A method for recycling used automobiles, in which the rectangular parallelepiped-shaped scrap car press scraps obtained without being used are melted together with city scraps, and scrap car press scraps whose sum L of the three sides is 1300 mm or more Used together with the scrap car scrap compounding ratio R (mass%)
Is within the range of the following formula (1) for the removal rate X (mass%) of the combustible member from the scrap car and within the range of the following formula (2) for the sum L (mm). Press scraps and city scraps in the melting chamber while supplying scrap car press scraps and city scraps to the preheating chamber so that the press scraps or city scraps remain unmelted in the melting chamber and the preheating chamber Is melted by the heating source, and the molten metal is discharged when a predetermined amount of the molten metal is generated in the melting chamber. R ≦ 0.6X + 30 (1) R ≦ − (1/30) L + 120 (2) 2. The method for recycling used automobiles according to claim 1, wherein the heating source is arc heating.