JP3438040B2 - Melting method of processing waste, weight for melting and compressed lump for melting of processing waste - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for melting machining scraps generated when aluminum or an alloy containing aluminum as a main component is subjected to machining such as cutting or grinding, and a method for melting the same. It relates to a melting weight and a compressed melt mass applied.

[0002]

2. Description of the Related Art Conventionally, when machining a metal material such as cutting or grinding, in order to improve the reduction rate of the metal material, metal machining waste generated during the machining is collected. I am trying to reuse it. That is, the collected metal working scraps are put into a molten metal to melt it, and then solidified so that it can be reused as a metal material.

[0003]

By the way, in the case where the above-mentioned metal material is aluminum or an alloy containing aluminum as a main component, most of the aluminum is liable to be oxidized when it is added to the molten metal. It becomes aluminum oxide (ash), and the amount reduced to aluminum is significantly reduced.

Further, in the recent machining, since water-soluble cutting and grinding oils are often used, dehydration prior to melting of aluminum machining wastes,
Each step of drying and deoiling must be performed, a large-scale facility equipped with each of these steps is required, and the reduction processing time of the processing waste increases significantly.

In view of the above-mentioned circumstances, an object of the present invention is to improve the reduction rate of aluminum, to simplify the process and to shorten the reduction treatment time, and a method for melting processing waste, and a method for melting the same. The object is to provide a melting weight and a compressed mass for melting applied at the time.

[0006]

According to the present invention, a compressed mass containing water and oil is charged into a crucible having a molten aluminum base water stored therein to preheat the compressed mass, and the preheating compresses the compressed mass. A preheating step including a drying step of evaporating the moisture of the lump to dehydrate and dry, and following this preheating step,
A heating step including a deoiling step of oxidizing and burning the oil components of cutting oil and grinding oil adhering to the compressed mass inside the crucible, and a lid-shaped weight on the compressed mass during melting after the deoiling step. And placing the compressed mass in the molten metal.

Further, in the present invention, a melting weight for burying a compressed mass formed by compressing aluminum processing waste in the molten metal during melting is generated in the upper layer portion when the aluminum is melted. The oxide formed is separated from aluminum and the oxide is solidified to form.

Further, according to the present invention, a compressed mass of aluminum processing waste used for melting, which has an apparent specific gravity of 1.
It is 60 to 1.68 and the water content is 7 to 9% by weight.

[0009]

[0010]

[0011]

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings showing an embodiment. FIG. 4 schematically shows factory equipment to which the method for melting machining waste according to the present invention is applied. Die casting of a crankcase or a cylinder head of an engine is performed by using aluminum or an alloy containing aluminum as a main component. This is an example of factory equipment for processing products.

In this factory equipment, the molten metal produced in the melt tower 1 is automatically supplied to the die casting process 2 in sequence to produce the above-mentioned various die casting products. The die cast products manufactured in the die casting process 2 are
After passing through the deburring step 3 and the inspection step 4, it is conveyed to each machining step 5, where necessary machining such as cutting and grinding is performed.

The aluminum processing waste a generated in each machining step 5 by machining such as cutting and grinding is crushed finely by a recovery line 6 composed of a screw conveyor, successively conveyed downstream, and accumulated in one place. . In the case where the above-mentioned machining step 5 includes a material for cutting or grinding metal materials other than aluminum and an alloy containing aluminum as a main component, a separate recovery line for these processing scraps is provided. Therefore, it is necessary to prevent the processing scraps of different materials from being mixed into the processing scraps a of aluminum.

The aluminum processing wastes a accumulated in one place are accommodated in a cylindrical cylinder C arranged on a flat plate and open at both ends, and then compressed by an appropriate compression device P, as shown in FIG. Then, as shown in FIG. 2 (c), it is held in a state of being molded into a cylindrical compressed mass A. Here, the dimensions of the compressed mass A are set so that the apparent specific gravity is 1.60 to 1.68 and the water content is 7 to 9% by weight, as is clear from the experimental results of FIG. Preferably
Under the compression conditions described above, the outer diameter is about 85 mm and the height is 4 mm.
It becomes 0 to 50 mm. The apparent specific gravity of compressed mass A is 1.60
The reason why it is set to ˜1.68 is that if the apparent specific gravity is higher than this, it takes a long time to oxidize (degrease) the cutting oil or the grinding oil adhering to the aluminum machining waste a, while the apparent specific gravity is lower than this. This is because when the specific gravity is large, the air content rate is increased, so that the processing waste a is easily oxidized and the generation rate of aluminum oxide is increased. The reason for setting the water content of the compressed mass A to 7 to 9% by weight is that if it is more than this, it takes a long time to remove water (dehydration / drying), but it is below this. This makes it difficult for the compressed mass A to maintain its shape, and the handling becomes complicated.

Aluminum machining waste a held in a cylindrical shape
The compressed mass A of the crucible 10 is then conveyed to the crucible 10 and
It will be heated and melted inside.

Hereinafter, referring to FIG. 1, this compressed mass A
The dissolution method of is described in detail.

First, the crucible 10 applied in the embodiment is called a graphite crucible made of graphite and has a thickness of about 1000.
It has an inner diameter of mm and its melting amount is 600 for aluminum.
It is set to kgf. This crucible 10 is shown in FIG.
As shown in (a), aluminum that has been melted in advance as the hot water 11 is 10 to 20 of the compressed mass A to be charged.
In the embodiment, 50 to 100 kgf is stored by an amount corresponding to%, and the burner 12 heats and holds the aluminum at a minimum melting temperature, specifically, 660 to 700 ° C. The original molten metal 11 is generated by melting an aluminum ingot, scrap, or the like only at the first melting, and the molten metal left in the final step described below will be used from the next time onward.

When the hot water 11 is prepared in the crucible 10, as shown in FIG. 1 (b), a large amount of the compressed mass A (up to 50 at most) is maintained while maintaining the above-mentioned heating state.
(Up to 0 kgf) at once. At this time, crucible 10
The inside of the compressed mass A is about 500 ° C., but this temperature is lower than the combustion temperature of aluminum, and the compressed mass A arranged at the bottom of the crucible 10 is
Being buried in 1 and being shielded from fresh air, each compressed mass A
Due to the evaporation of the water adhering to the inside, the air inside and around the compressed mass A is expelled to the outside, and the heating flame of the burner 12 blocks the upper part of the crucible 10 from fresh air, and so on. Because of oxygen deficiency,
Water is removed from the compressed mass A while the generation of aluminum oxide is suppressed. During this period, white smoke of water vapor is generated for about 30 minutes, and it can be judged that the drying of the compressed mass A is completed when the white smoke disappears.

When the above-mentioned heating state is continued even after the completion of the drying of the compressed mass A, the oil components such as the cutting oil and the grinding oil adhering to each compressed mass A oxidize with a flame of 50 to 100 cm. Approximately 1 hour after the oil is oxidized,
Since the combustion flame height of the oil content is reduced to 10 to 20 cm, the fuel supply to the burner 12 is cut off at this point,
Only air is supplied to completely oxidize the oil. During this time, each compressed mass A is melted from the time when the inside of the crucible 10 reaches the melting point of aluminum, and the molten metal 1 is melted inside the crucible 10.
3 will be sequentially generated. In addition, the above-described oxidation of the oil component is effective in keeping the temperature inside the crucible 10 and contributes to the fuel saving of the burner 12.

At the time when the oxidation of the oil component is completed, FIG.
After extinguishing the burner 12 as shown in FIG. 4, the lid-like weight 14 is placed on the undissolved compressed mass A ′ and left as it is for about 20 minutes. Here, compressed lump A '
The lid-like weight 14 placed on the upper part of the
The outer diameter corresponds to 0 to 70%, that is, it can be easily accommodated in the crucible 10 and fresh air from the outside is prevented as much as possible, and the compressed mass A ′ is buried inside the molten metal 13. It has a cylindrical shape with sufficient weight to
As will be described later, it is configured by using aluminum oxide removed from the molten metal 13.

As described above, the lid-shaped weight 1 is provided on the compressed mass A.
In the state where 4 is placed, the undissolved compressed mass A ′ is buried in the molten metal 13 to be shielded from the fresh air, and the fresh weight into the crucible 10 is caused by the lid-shaped weight 14. As a result, the generation of aluminum oxide and the oxidation of the molten metal 13 are prevented as much as possible. In addition, the lid-shaped weight 14 itself is also sequentially melted and included in the molten metal 13 in the crucible 10.

About 20 minutes after extinguishing the burner 12, the compressed mass A and the lid-shaped weight 14 are almost completely melted, but aluminum oxide is mixed in the molten metal 13. Therefore, the work of separating the aluminum oxide is performed next. That is, as shown in FIG. 1 (d), after the flux is put into the crucible 10, the molten metal 13 is stirred by the stirring rod 15 for about 10 minutes. As a result, the aluminum oxide 16 having a small apparent specific gravity is eventually separated and floated on the upper layer portion in the molten metal 13.

After the burner 12 is re-ignited and the molten metal is maintained for a predetermined time, a small amount of sodium nitrate is added to scoop out the aluminum oxide 16 floating in the upper layer to the outside. Only the high aluminum melt 13 remains, and as shown in FIG. 1 (f), the molten aluminum 13 is poured into an ingot mold 17 to be solidified or directly transferred to the melt tower 1 described above, so that the aluminum It can be used as a metal material. However, as described above, a part of the molten metal 13 is left inside the crucible 10 so as to be used as the original molten metal 11 in the next melting.

On the other hand, since the aluminum oxide 16 scooped out from the crucible 10 contains a large amount of aluminum, it is poured into a filter 18 called an ash squeeze funnel as shown in FIG. 1 (e). Then, after the aluminum oxide is further removed by stirring with a flat plate-shaped stirrer 18a as shown in FIG. 3, it is solidified into a cylindrical shape inside the container 19. The solidified substance in the container 19 contains about 70% of aluminum, and is effectively used as the above-mentioned lid-like weight 14 in the next melting.

According to the results of experiments conducted by the inventors, the reduction rate of aluminum by the above method is 90%.
It was very high at ˜91%, and the total reduction treatment time was about 2 hours.

As described above, according to the above-described method for melting the processing mass, the compressed mass A of the processing waste a is preheated by charging the compressed mass A into the original hot water 11, and the preheating causes the compressed mass A to be compressed. Since dehydration, drying, and deoiling are performed, it is not necessary to separately provide these facilities, and the process can be simplified. Further, during melting, the lid-like weight 14 is placed on the undissolved compressed mass A'and the compressed mass A'is melted.
Since it is soaked in 3, the generation of aluminum oxide is suppressed by preventing contact with the outside air, and the reduction rate of aluminum can be improved.

Moreover, since the lid-shaped weight 14 is obtained by separating and solidifying aluminum oxide, the aluminum contained in the weight 14 is also reduced as a metal material, and the reduction rate of aluminum is further improved. improves.

Further, the apparent specific gravity of the compressed mass A is 1.60.
˜1.68, and the water content is set to 7 to 9% by weight, the air content is suppressed as much as possible without increasing the deoiling time and the dissolution time, and the generation of aluminum oxide is generated. It is possible to improve the reduction rate of aluminum by suppressing the above, and it is possible to prevent an increase in the drying time without causing the collapse of the compressed mass A and to shorten the reduction treatment time. Become.

In the above embodiment, since the processing waste is formed into a cylindrical compressed mass, it can be easily formed with a relatively simple device, but in the present invention, it is not necessarily formed into a cylindrical shape. do not have to. However, it is ideal that the compressed mass has a surface area as small as possible with respect to the volume, and it is desirable that the compressed mass is formed into the columnar shape or the spherical shape shown in the above-mentioned embodiment.

[0031]

As described above, according to the method for melting working scraps of the present invention, the compressed mass of the working scraps is preheated by feeding the compressed mass of the working scraps into the hot water. Since dehydration, drying and oil removal are performed, the process can be simplified. In addition, since the compressed mass is buried in the molten metal during melting and the contact between the compressed mass and the outside air is prevented, the generation of aluminum oxide is suppressed, so that the reduction rate of aluminum can be improved.

Further, according to the melting weight of the present invention, since the oxide of aluminum is separated and solidified, the aluminum contained in this weight can be reduced to the metal material, and the reduction of aluminum can be achieved. The rate can be improved.

Further, according to the compressed mass for dissolving processed scraps of the present invention, when the apparent specific gravity is 1.60 to 1.68, the deoiling time and the dissolution time of the compressed mass are not increased. Since the content rate of air can be suppressed as much as possible, generation of aluminum oxide is suppressed, and the reduction rate of aluminum can be improved. When the water content is 7 to 9% by weight, the drying time can be prevented from increasing without causing the collapse of the compressed mass, and the reduction treatment time can be shortened.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing, in order, a method for melting processing scraps according to the present invention.

FIG. 2 is a conceptual diagram sequentially showing a method for forming a compressed lump for dissolution.

FIG. 3 is a sectional view conceptually showing an ash pressing funnel used in the present invention.

FIG. 4 is a plan view schematically showing factory equipment to which the method for melting machining waste according to the present invention is applied.

FIG. 5 is a chart showing the relationship between the outer diameter of the compressed mass for dissolution, the dissolution treatment time, and the reduction rate to aluminum.

[Explanation of symbols]

10 ... crucible 11 ... Motoyu 13 ... Molten metal 14 ... Weight 16 ... Aluminum oxide a ... Aluminum processing waste A, A '... Compressed mass

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsuji Nakamura 3200 Mizushima, Oyabe City, Toyama Prefecture Suzuki Parts Toyamauchi (72) Inventor Shinichi Maeda 3200 Mizushima, Oyabe City, Toyama Prefecture Suzuki Parts Toyamauchi (56) ) References: Actual Open Sho 60-2293 (JP, U) Actual Open Flat 1-129250 (JP, U) Actual Open Sho 49-7103 (JP, U) Actual Open Sho 60-176900 (JP, U) Japanese Patent Publication 5-67687 (JP, B2) (58) Fields surveyed (Int.Cl. ⁷ , DB name) C22B 1/00-61/00

Claims (3)

(57) [Claims] Claims: 1. A compressed mass containing water and oil is charged into a crucible having a molten aluminum source water stored therein to preheat the compressed mass, and the preheating evaporates the water content of the compressed mass for dehydration. A preheating step including a drying step of drying, and a heating step including a deoiling step of oxidizing and burning the oil components of the cutting oil and the grinding oil adhering to the compressed mass inside the crucible after the preheating step, and the deoiling step A method for melting processing chips, which comprises the step of placing a lid-shaped weight on the compressed mass and immersing the compressed mass in the molten metal during the melting after the completion. 2. A melting weight for burying a compressed mass formed by compressing aluminum processing waste in a molten metal during melting, which is generated in an upper layer portion when aluminum is melted. A weight for melting, characterized by being formed by separating an oxide from aluminum and solidifying the oxide. 3. A compressed mass of aluminum working chips used for melting, characterized by having an apparent specific gravity of 1.60 to 1.68 and a water content of 7 to 9% by weight. Compressed mass for melting.