JPH07216471A - Recovery treatment of aluminum dross and device therefor and aluminum dross - Google Patents

Abstract

PURPOSE:To provide a recovery treatment method and a device capable of adequately recovering the used aluminum from the hot aluminum dross generated in the process of melting or alloying and smelting or melting treatment, such as refining, of aluminum or aluminum alloy and effectively obtaining the aluminum dross preferable for utilization as a treating agent for iron making or steel making. CONSTITUTION:The dross 9 adjusted to the m.p. of aluminum or above is housed on a perforated plate 11 or on the bottom plate of a vessel formed with slits. Vibrations are acted together with pressing down force on the dross 9 to rupture the oxidized film of the molten aluminum in the dross 9 and to improve separability of air. As a result, flow components are expelled from aluminum liquid drops and air, and the density of the solid-content of the aluminum oxide, etc., in the dross is increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum dross recovery treatment method and apparatus, and an aluminum dross lump, for melting or alloying aluminum or an aluminum alloy (hereinafter simply referred to as "aluminum") or performing melting treatment such as refining. To appropriately recover molten aluminum from hot aluminum dross generated in the process and effectively obtain a preferable aluminum dross to be used as a deoxidizing, heat retaining or temperature increasing agent used in a steel manufacturing process such as ironmaking or steelmaking. It is intended to obtain a recovery treatment method and an apparatus therefor capable of further providing an aluminum dross lump as a low-cost treatment agent that can effectively carry out deoxidation treatment on iron or steel as described above. is there.

[0002]

2. Description of the Related Art It is inevitable that aluminum dross will be generated during the melting treatment of aluminum or aluminum alloys, and the recovery of metallic aluminum from such aluminum dross has been extensively studied. That is, in order to recover metallic aluminum from such an aluminum dross, a flux is generally added to the dross conventionally stored in a container to heat the aluminum by oxidation to weaken the oxidized film and enhance the fluidity of the molten metallic aluminum, By mechanically stirring such aluminum dross, the oxide film is broken, and the aluminum droplets that have grown by combining the metals are settled at the bottom of the container and separated.

On the other hand, in Japanese Unexamined Patent Publication No. 60-500542 (Japanese Patent Publication No. 62-10287), the pressing tool is pressed to the upper part, and the pressing tool is lowered at the maximum speed until the liquid aluminum flow appears in the lower part of the mold. After that, it is announced that the pressing tool is lowered at a speed which becomes slower as the concentration of liquid aluminum decreases.

On the other hand, JP-A-47-38719 (Japanese Patent Publication No.
(JP-A-37881), there is proposed a synthetic slag adjusting material which is formed in a lump form by using an appropriate binder for the aluminum dross, and in JP-A-51-97524 (Japanese Patent Publication No. 56-30368), this aluminum dross is proposed. With a mixture of lime and lime as the main component and a melting point of 1450-
A synthetic slag adjusting material for steelmaking at 1600 ° C. has been proposed.

Further, JP-A-62-205210 (Japanese Patent Publication No.
-9643), it was announced that a mixture of aluminum dross mixed with iron, steel dust, and the like was charged into a ladle to cause an oxidation reaction, which is disclosed in JP-A-3-12220.
9, JP-A-3-122210 also announced that the refining agent added to the dephosphorization furnace contains aluminum dross together with fluorite.

[0006]

According to the conventional general method for recovering metallic aluminum from aluminum dross as described above, it is impossible to recover 100% of the metal, and the metallic aluminum equivalent to the dross after the treatment is not available. Residue is unavoidable. In addition, since the added flux burns the metal in the aluminum dross to achieve high heat, there is a large metal loss, and there is a risk of explosion due to a rapid oxidation reaction, and further wear and wear of the device due to stirring. There are disadvantages such as being large.

It can be said that the squeezing using pressure according to Japanese Patent Laid-Open No. 60500542 described above eliminates the disadvantages of the conventional general method as described above, but the high temperature aluminum dross is entrained with molten metal aluminum. It consists of fluid such as air and powder such as aluminum oxide and aluminum nitride.When such aluminum dross is filled in a container and a load is applied, an arching phenomenon occurs due to internal friction of coarse dross powder. It will be generated and the transmission of force will be hindered and the discharge of fluid will be insufficient,
The amount of air remaining is still large, and the oxidation of aluminum contained in the dross progresses, resulting in a significant increase in the weight of the dross. It has to be significantly lower. The energy required for squeezing is also large.

The technique of utilizing aluminum dross for the steel refining or slag adjustment according to the above-mentioned JP-A-47-38719 and JP-A-62-205210 is in any case concerned with effective utilization of dross generated during aluminum refining. Although it is clear that this is a technology, the use of such aluminum dross essentially aims to oxidize aluminum to reduce oxygen in the steel and to utilize the heat generated by the oxidation to improve the properties of steel and the like. Therefore, it is important to have a high aluminum metal content in the dross, and the maximum aluminum metal content is 30.
When the dross is as low as about 10%, not only the above-mentioned action is poor, but also the amount of slag generated is increased to make the treatment difficult. Therefore, in the case where the aluminum metal content is low as described above, a special cost is required for the treatment as merely industrial waste, and it is inevitable to dispose of it.

[0009]

Means for Solving the Problems The present invention has been studied to solve the problems of the prior art as described above, the oxide film of molten metal aluminum in dross is destroyed by a specific vibration treatment, and the dross particles are By moving the powder under the condition that the arching is broken and a uniform force is transmitted, a reduction force is applied to collect the aluminum droplets and the dross particles move to the residual voids to fill the voids and flow components such as air. It was effectively eliminated to suppress the oxidation of aluminum and to densify the solid content, and succeeded in obtaining an industrially advantageous aluminum dross lump, which is as follows.

(1) A dross having a melting point of aluminum or more is housed on a container bottom plate having an opening, and vibration is applied to the dross from above and below while pressing down the dross. Aluminum which is characterized by breaking the oxide film of molten metal aluminum and improving the separability of air, eliminating fluid components consisting of aluminum droplets and air, and densifying solid content such as aluminum oxide in dross. Dross recovery processing method.

(2) The dross contained in the container and having a melting point of aluminum or higher is subjected to a downward force caused by an upward piston as well as a downward force caused by a piston accompanied by an upward vibration. The method for recovering and treating aluminum dross according to the item.

(3) A dross contained in a container and having a melting point equal to or higher than the melting point of aluminum is provided with a vibration having a frequency of 0.5 to 100 hz and an amplitude of 0.1 to 10 mm from above as well as from below. The method for recovering aluminum dross according to (1) or (2) above.

(4) A fluidized product having a machine base adapted to set a container having at least a large number of openings on the bottom surface, a pressing means provided on the upper part of the machine base, and squeezed out below the container. And a vibrating mechanism that acts on the above-mentioned container are vertically installed on the machine base so as to be opposed to each other.

(5) A means for receiving the squeezed fluid is provided at the bottom of the container having a collar so that it can be attached and detached, and a support seat for supporting the collar is formed on the machine base, and is moved up and down on the support seat. The apparatus for recovering aluminum dross according to the item (4), which is provided with an operating means.

(6) The above-mentioned (4) is characterized in that the container is provided with a pressing means from the bottom as well as a pressing means from the top, and each of these pressing means is provided with a vibrating mechanism. Alternatively, the aluminum dross recovery processing apparatus described in the above item (5).

(7) The apparatus for recovering and treating aluminum dross according to item (4) or (6), wherein the vibrating mechanism is a hydraulic mechanism.

(8) A lump formed by removing aluminum droplets from aluminum dross, which has an aluminum content of 3
An aluminum dross lump characterized by having a bulk specific gravity of not less than 5% and not less than 2.0 gr / cm ³ .

(9) An aluminum dross mass obtained by removing aluminum droplets from aluminum dross, having an aluminum content of 35% or more and a bulk specific gravity of 2.0 gr / cm.
^A treating agent for the production of steel, characterized by having ³ or more.

[0019]

The molten metal in the dross is accommodated on the bottom plate of the container in which the opening is formed by accommodating a dross having a melting point of aluminum or more and applying vibration to the dross from above and downward while pressing down the dross. Efficiently obtains the action of breaking the aluminum oxide film and improving the separability of air, and appropriately removes the fluid components consisting of aluminum droplets and air by the above-mentioned pressing force and increases the solid content such as aluminum oxide in dross. It is possible to increase the density.

With respect to the aluminum dross contained in the container as a whole, the dross contained in the container and having a melting point higher than the melting point of the aluminum is subjected to the downward pressure of the piston accompanied by the vibration from the upper side as well as the pressing force of the upward piston. A uniform pressing force is applied to eliminate fluid components in a uniform state.

For a dross contained in a container and having a melting point higher than that of aluminum, the frequency is 0.5 to 100 hz and the amplitude is 0.5.
1-10 mm, preferably 0.1-5 mm, more preferably 0.1.
By giving a vibration of 2 to 4 mm, the separation of the dross flow component, especially the air component is improved. If the frequency is less than 0.5 hz, it will take a long time to fill, and the fluidity of the metal will deteriorate and the oxidation will progress due to the decrease of the dross temperature. If it exceeds 100 hz, the durability of the vibrator deteriorates. If the amplitude is less than 0.5 mm, the filling effect is small and it takes time, and if it exceeds 7 mm, the noise becomes loud. More preferable frequency is 10-60hz
The preferable range of the amplitude is 0.1 to 5.0 mm, more preferably 0.2 to 4.0 mm.

At least a bottom is provided with a machine base for setting a container having an opening formed therein, and a pressing means is provided on an upper part of the machine base, and a means for receiving a fluid squeezed out below the container. By providing the above-mentioned vibrating mechanism that acts on the container on the machine base, pressurization and vibration can be effectively applied to the dross contained in the container.

A means for receiving the squeezed fluid is provided at the bottom of the container having a collar so as to be attachable / detachable, a support seat for supporting the collar is formed on the machine base, and a lifting operation means is provided on the support seat. By providing the container, the container can be moved to the vicinity of the aluminum refining furnace to receive the scraped aluminum dross, which can be immediately transferred to the processing device for recovery processing.

Since the pressure means from the top and the pressure means from the bottom are provided to the container and the vibration mechanism is provided to each of these pressure means, the container is located in the center of the container and is even and efficient. The vibration is applied by the pressurizing means for performing the pressurization, and the pressurization and the vibration are both achieved by the simple equipment.

Since the vibrating mechanism is a hydraulic mechanism such as hydraulic pressure, vibration is effectively imparted, and the dross compression due to the vibration is performed appropriately to separate liquid components such as liquid metal and air in the dross. Facilitate.

A lump formed by removing aluminum droplets from aluminum dross, and having an aluminum content of 35% or more, it efficiently achieves refining or manufacturing treatment purposes such as deoxidation on steel, steelmaking, heat retention or temperature rise. Of the above-mentioned treatment agents at low cost by further reducing the amount of slag generated during the treatment to perform an advantageous treatment operation and further aiming at the use of dross, which conventionally required a cost for waste treatment. In any case, an advantageous refining or manufacturing process is performed.

The bulk specific gravity of the aluminum dross mass is 2.0.
By setting the gr / cm ³ or more, the aluminum dross lumps can be made compact and powdered to be easily handled or stored, and the air content in the dross lumps can be reduced to reduce the oxidation loss of aluminum. In order to improve the efficiency of the processing purpose on the above-mentioned iron making and steel making.

The preferred aluminum content in the aluminum dross lump described above is 40% or more. By thus setting the aluminum content to 40% or more, the efficiency of the above-mentioned processing purpose in iron making and steelmaking can be improved. be able to.

[0029]

EXAMPLES To explain specific embodiments of the present invention as described above, the dross treatment method according to the present invention is a method in which a dross is scraped out of an aluminum melting furnace in a container having a bottom plate having a large number of holes. Destruction of the oxide film on the molten metal aluminum in the dross by press-fitting a pressing part body such as a piston under the condition of vibrating from the top by accommodating the dross which is kept above the melting point of aluminum and is preferably scraped out. At the same time, it is intended to separate and discharge the fluid component.

Generally, the size of the opening in the bottom plate of the container is preferably about 10 to 30 mm, and the width of about 10 to 20 mm is suitable in the case of a slit shape. The opening area is preferably 10% or more. If the size of the opening is less than 10 mm or the area of the opening is less than 10%, clogging is likely to occur and it becomes difficult to discharge liquid aluminum or air. On the other hand, if it exceeds 30 mm or the slit width exceeds 20 mm, not only the fluid component but also the aluminum dross may drop, which is not preferable.

For pushing by the piston, 2 to 10
It is preferable to have a capability of MPa, and it is appropriate that the pushing speed is generally about 5 to 60 cm / min. If the pushing speed is slow, such as less than 5 cm / min, it takes time to process. Therefore, the oxidation and nitridation of the metal in the dross proceed and the cooling of the dross lowers the fluidity of the metal, and in any case, the recovery cannot be efficiently performed. On the other hand, when the pushing speed is as high as 60 cm / min or more, the pushing pressure increases due to the internal resistance of the powder and the like, the energy efficiency is poor and the filling is not sufficiently performed. Occurs, and the commercial value of the dross after processing decreases.

The vibration applied to the dross from above and below is transmitted to the dross through the piston by the vibrator attached to the piston, or by the vibrator attached to the perforated plate such as a grating provided at the bottom of the container. May be transmitted to Dross via.

An example of the device according to the present invention is as shown in FIGS. 1 and 2, and a specific example is an inner diameter of 500 mm.
The iron cylindrical container 1 having a height of 500 mm is supported by the support seat 16 of the machine base 10 through the receiving means 2 and
60000-90000 cm ³ of dross material can be charged, and the receiving means 2 provided at the bottom of the container 1 has a conical projection 21 formed at the center thereof, and the receiving means 2 is provided on the circumferential side. The receiving portion 22 is arranged in a ring and is connected to the bottom of the container 1 by the connecting means 23 so as to be moved.

A perforated plate 11 such as a grating is attached to the bottom surface of the container 1 described above, and a flange portion 12 is projectingly provided on the top portion. The flange portion 12 is on the intermediate side of the machine base 10. The pedestal 13 is supported by a pedestal 13 opposite thereto, and the pedestal 13 is moved up and down by a push-up cylinder 14 mounted on the machine base 10 and a guide 7. That is, the container 1 and the receiver 2 are detached from the receiving base 13 and set to the side of the aluminum melting furnace 6 as shown in FIG. Stand 10
It is carried into the container and is subjected to the recovery processing according to the present invention.

A pressing plate 8 is placed on the dross 9 housed in the container 1 and is pressed by the piston head 41 of the pressing cylinder 4 provided on the machine base 10. A pipe 42 from a hydraulic unit is guided to the cylinder 4 to perform servo-actuator pressure excitation.

Further, a lower pressure oscillating cylinder 5 is provided at the bottom of the machine base 10, and its head 51 enters the lower surface of the conical projection 21 of the receiver 2 and acts on the bottom of the container. Therefore, the pipe 52 from the hydraulic unit is also connected to the cylinder 5.

The cake of dross, which has been compressed and positioned at the bottom of the container 1 after being subjected to the recovery processing by the cylinders 4 and 5 in the container 1, is transferred to a cake receiving pallet, and the cake extracting cylinder is used. It is well known that it is taken out of the container 1 and taken out on the cake receiving pallet by receiving the taking out by
The container 1 from which the cake has been taken out is transferred to the side of the aluminum melting furnace 6 to receive new aluminum dross, as shown in FIG.

Explaining examples and comparative examples according to the present invention which are carried out by using the above-mentioned apparatus, as described above, the diameter is 500 mm and the height is 500 mm, and the size of the opening is 15 mmφ and the opening area is 20 mm. As shown in FIG. 3, the scraping opening 62 of the aluminum melting furnace 6 for the cylindrical iron container 1 having the perforated plate 11 set to
The dross 9 at a temperature of about 750 ° C., which was scraped out by the scraping tool 3, was appropriately stored with 30 to 40 kg as a guide. That is, it is practically impossible for the scraped dross to accurately weigh a certain amount,
Since the aluminum content is oxidized and deteriorated in sequence during and after the scraping, as an example in accordance with the actual situation of work, the scraping dross is accepted as an approximate target of about 30 to 40 kg, and this is immediately input to the recovery processing device. I decided to send it and process it.

The detailed conditions in the comparative examples and the examples of the present invention are as shown in Table 1 which will be described later. However, as a conventional example, only pressing is performed only by a piston at the upper part of the container. As a comparative example, only the pressure vibration by the piston on the upper part of the container was applied. In contrast to the conventional example and the comparative example, in the example of the present invention, the upper piston is pushed and then the pushing pressure is continuously applied while the upper and lower pistons vibrate.

A summary of the results of these treatments is shown in Table 1 which will be described later. In the case where only conventional pressurization is used, the bulk specific gravity of the dross obtained after the treatment is proportional to the applied pressure. It is obvious that the bulk specific gravity becomes considerably low even if it is changed by the above, whereas the bulk specific gravity becomes considerably high due to the addition of the pressure applied to the upper portion and the bidirectional vibrations of the upper portion and the lower portion.

Further, as can be seen in the comparative example, the bulk specific gravity of the post-treatment dross becomes even higher by applying the vibrations in the upper and lower directions as compared with the vibration in the one direction. The high bulk specific gravity means that the oxidation of the aluminum metal component in the dross was suppressed during the treatment, which is also evidenced by the high content of metallic aluminum in the dross after the treatment.

[0042]

[Table 1]

The pressure required to push the piston is the same regardless of the presence or absence of vibration and the vibration from the vertical direction. The weight of the recovered aluminum, that is, the recovery rate of metallic aluminum contained in the raw material is 54 to 58%. Is the same as
The metal aluminum content contained in the dross after metal recovery is about 10% in the case of conventional indentation, whereas it is about 30% in the case of applying vibration, and even to 40% by adding vibration from the top and bottom. To be enhanced. From the high aluminum content and the high bulk specific gravity described above, it was confirmed that the vibration is suppressed and the solidification is effectively achieved by vibrating both in the vertical direction. .

It is estimated that the high bulk specific gravity and high metal aluminum content after the treatment were due to efficient discharge of air in the scraped dross and suppression of oxidation in the dross after the treatment. To be done. That is, when the oxidation of aluminum progresses during the treatment, the amount of metallic aluminum decreases and it changes to 1.9 times the weight of alumina (Al + O ₂ → Al
₂ O ₃ ) reduces the aluminum content in the dross and increases the dross weight after the treatment, increasing the treatment amount. That is, according to the present invention, the dross weight increase rate is 3
It is found that the conventional example has 21 to 22%, and the comparative example has 12%, and the method of the present invention has an effect of suppressing Al partial oxidation in dross.

Thus, the fact that the Al% of the present invention is increased in this way means that after this treatment, the dross is a deoxidizing and heat retaining agent as a treating agent containing an auxiliary agent in the manufacturing process of steel such as iron making, steel making, refining and casting. Alternatively, when used for any purpose such as temperature increase, each purpose can be effectively achieved by adding a relatively small amount, and the amount of slag generated is also small by the addition, which can be sufficiently and advantageously utilized. It also indicates that the amount of reuse and reprocessing is not unnecessarily increased.

[0045]

In the present invention as described above,
It is possible to recover metallic aluminum from the dross held above the aluminum melting point without using flux, and the metallic aluminum remaining in the dross after the treatment remains in the dross without causing oxidation or nitriding. Since dross with a high aluminum concentration can be obtained, the conventional one has a low aluminum concentration, so it contaminates the hot metal, molten steel, etc., making it difficult to clean it, making it difficult to use, and having to deal with it as waste. Instead, it is an invention that is industrially effective in that it can be used as a useful resource.

[Brief description of drawings]

FIG. 1 is a front view of an aluminum dross recovery processing apparatus according to the present invention.

FIG. 2 is a side view thereof.

FIG. 3 is a cross-sectional view showing a dross scraping operation state in an aluminum melting furnace.

[Explanation of symbols]

 1 Container 2 Receiving Means 3 Dross Scratching Tool 4 Pressing Cylinder 5 Pressurizing Excitation Cylinder 6 Melting Furnace 7 Guide 8 Pressing Plate 9 Dross 10 Machine Stand 11 Perforated Plate 12 Collar 13 Pusher Cylinder 16 Support Seat 21 Cone Shape Projection portion 22 Receiving portion 23 Connection means

Front page continuation (72) Inventor Hiroshi Watanabe 1-34-1, Kambara, Kambara-cho, Anbara-gun, Shizuoka Nipparu Giken Co., Ltd. Company Kambara Factory (72) Inventor Masatoshi Nanba 3-13-12 Mita, Minato-ku, Tokyo Inside Japan Light Metals Co., Ltd. (72) Inventor Kunio Hayashi, 351 Ejiri, Takaoka-shi, Toyama Prefecture Hokuko Co., Ltd.

Claims (9)

[Claims] 1. A dross having a melting point of aluminum or more is accommodated on a container bottom plate having an opening, and vibration is applied to the dross from above and below while pressing down the dross. Aluminum dross characterized by breaking the oxide film of molten metal aluminum and improving the separation of air, eliminating fluid components consisting of aluminum droplets and air, and densifying solid content such as aluminum oxide in dross Recovery treatment method. 2. A dross having a melting point equal to or higher than the aluminum melting point contained in a container is made to act not only by a downward force generated by a piston accompanied by vibration from above but also by a downward vibration caused by an upward piston. For recovering treated aluminum dross. 3. A dross contained in a container and having a melting point equal to or higher than that of aluminum has a frequency of 0.5 to 100 hz and an amplitude
The method for recovering aluminum dross according to claim 1 or 2, wherein vibration of 0.1 to 10 mm is applied from above as well as from below. 4. A fluid machine squeezed below the container, which has a machine base for setting a container having a large number of openings at least on the bottom surface, and which is provided with a pressing means at the upper part of the machine base. An apparatus for collecting and processing aluminum dross, characterized in that a receiving means is provided, and a vibration mechanism that acts on the above-mentioned container is vertically installed on the machine base. 5. A means for receiving and squeezing out the squeezed fluid is provided at the bottom of the container having a collar so as to be attachable / detachable, a support seat for supporting the collar is formed on the machine base, and a lifting operation is performed on the support seat. An aluminum dross recovery processing apparatus according to claim 4, further comprising means. 6. The container according to claim 4, further comprising a pressurizing means from the top and a pressurizing means from the bottom of the container, and each of the pressurizing means is provided with a vibrating mechanism. The aluminum dross recovery processing apparatus described in 5. 7. The apparatus for recovering and treating aluminum dross according to claim 4, wherein the vibrating mechanism is a hydraulic mechanism. 8. A lump obtained by removing aluminum droplets from aluminum dross, wherein the aluminum content is 35%.
The above is the aluminum dross lump having a bulk specific gravity of 2.0 gr / cm ³ or more. 9. An aluminum dross lump obtained by removing aluminum droplets from an aluminum dross, which has an aluminum content of 35% or more and a bulk specific gravity of 2.0 gr / cm ³ or more. Treatment agent.