Method for producing aluminum raw materials, method for producing aluminum material, and compression apparatus

Abstract

To provide a method for producing an aluminum raw material that allows impurities to be easily and adequately removed from an aluminum massive body.SOLUTION: A method for producing an aluminum raw material according to one aspect of the present disclosure comprises: a step of raising a temperature of a massive body of aluminum containing impurities so as to be brought into a semi-molten state; a step of pressing the temperature-raised massive body with a pressing member; and a step of recovering, as an aluminum raw material, a solid phase from which a liquid phase containing at least a part of the impurities is separated by pressing the massive body, wherein, in the pressing step, a heat insulating member is disposed between the pressing member and the massive body.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a method for producing an aluminum raw material, a method for producing an aluminum material, and a pressing device.

Background Art

[0002] Currently, from the perspective of resource depletion, recycling of various materials has been progressing, and recycling of metals that are consumed in large quantities has also been carried out for a long time. A method is known for removing unnecessary elements from recycled aluminum and making a material containing desired elements (Japanese Patent Laid-Open No. 5-098363).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1, a mass of aluminum containing elements (impurities) such as Cu whose removal is desired is heated to the solid-liquid coexistence temperature range and deformed, so that the central part is a solid-phase main region (solid phase), and the peripheral part is a liquid-phase main region (liquid phase) containing a part of the above impurities. The solid phase with reduced impurities is obtained by cutting and separating the solidified liquid phase. In this method, it is said that the impurity concentration in the solid phase can be reduced by flowing the impurities into the liquid phase, but it is desired to remove the impurities more easily and sufficiently.

[0005] In view of such circumstances, an object of the present disclosure is to provide a method for producing an aluminum raw material capable of easily and sufficiently removing impurities from a mass of aluminum.

Means for Solving the Problems

[0006] The inventors have discovered that when a semi-molten aluminum mass is compressed in air after being heated, unlike when aluminum precipitates are compressed in molten metal, the temperature of the mass drops rapidly due to heat dissipation from the pressing member that presses the mass, and this temperature drop reduces the effectiveness of impurity removal from the mass. The inventors have diligently studied means to suppress the above heat dissipation and have completed the invention disclosed herein.

[0007] A method for producing aluminum raw material according to one aspect of the present disclosure that solves the above problems comprises the steps of: raising the temperature of an aluminum lump containing impurities to a semi-molten state; pressing the heated lump with a pressing member; and recovering the solid phase, from which the liquid phase containing at least a portion of the impurities has been separated by pressing the lump, as aluminum raw material, wherein a heat insulating member is placed between the pressing member and the lump in the pressing step. [Effects of the Invention]

[0008] The method for producing aluminum raw materials described herein allows for easy and sufficient removal of impurities from aluminum in bulk form. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic front cross-sectional view showing a compression device that is one embodiment of the present disclosure. [Figure 2] Figure 2 is a graph showing the temperature change of the aggregate in the embodiment of this disclosure. [Figure 3] Figure 3 is a graph showing the temperature change of other aggregates in the embodiments of this disclosure. [Modes for carrying out the invention]

[0010] [Description of Embodiments in this Disclosure] First, the embodiments of this disclosure will be listed and described.

[0011] (1) A method for producing an aluminum raw material according to one aspect of the present disclosure comprises the steps of: raising the temperature of an aluminum lump containing impurities to a semi-molten state; pressing the heated lump with a pressing member; and recovering the solid phase, from which the liquid phase containing at least a portion of the impurities has been separated by pressing the lump, as an aluminum raw material, wherein in the pressing step, a heat insulating member is placed between the pressing member and the lump.

[0012] The method for producing the aluminum raw material involves heating an aluminum lump containing impurities to a semi-molten state and then pressing the heated lump. This allows for easy separation of the lump into a liquid phase containing at least some of the impurities and a solid phase with reduced impurities. The pressing member used to press the lump has an insulating member placed between it and the lump, allowing for pressing the lump while suppressing the temperature drop of the lump due to contact with the pressing member. This suppresses a reduction in the effect of impurity discharge from the lump (the effect of impurities flowing from the lump into the liquid phase in the molten state), and allows for easy separation of the liquid phase containing sufficient impurities from the lump. Therefore, the method for producing the aluminum raw material allows for easy and sufficient removal of impurities from the lump, and a solid phase with reduced impurity concentration (the lump from which the impurities have been removed) can be easily obtained as a high-purity aluminum raw material.

[0013] (2) In (1) above, the heat insulating member may be placed over the entire area in which the mass of the pressing member contacts the pressing member in a plan view. By placing the heat insulating member over the entire area in which the pressing member contacts the mass of the pressing member in a plan view, the temperature drop of the mass can be effectively suppressed.

[0014] (3) In the above (1) or (2), the heat insulating member may be a porous body or a cotton-like state having a plurality of voids. The recovered aluminum raw material may have a part of the heat insulating member attached thereto. When melting this aluminum raw material, since the heat insulating member is a porous body or a cotton-like body, a part of the heat insulating member is likely to float on the molten metal, so that a part of the heat insulating member in the molten metal can be easily removed.

[0015] (4) In any one of the above (1) to (3), in the pressing step, it may be pressed with the heated pressing member. By pressing with the heated pressing member, the temperature drop of the lump can be further suppressed.

[0016] (5) The method for producing an aluminum raw material according to another aspect of the present disclosure includes a step of heating a lump of aluminum containing impurities to a semi-molten state, a step of pressing the heated lump with a pressing member, and a step of recovering, as an aluminum raw material, a solid phase in which a liquid phase containing at least a part of the impurities is separated by pressing the lump. In the heating step, the pressing member is heated.

[0017] The pressing device that presses the lump in the manufacturing method of the aluminum raw material can suppress the temperature change of the pressed lump because it heats the pressing member that presses the lump, and can suppress the reduction of the discharge effect of the impurities in the lump. Therefore, the method for producing the aluminum raw material can easily and sufficiently remove the impurities from the lump, and can easily obtain a solid phase with a reduced impurity concentration as a highly pure aluminum raw material.

[0018] [[ID=1,6]](6) In any one of the above (1) to (5), a step of placing the lump on a filtering member may be further provided. By placing and pressing the lump on the filtering member, the liquid phase can be easily separated from the remaining part (solid phase) of the lump.

[0019] (7) In the above (6), a release agent may be applied to the filtering member. By applying a release agent to the filtering member, the ease of recovering the solid phase can be improved.

[0020] (8) In any one of the above (1) to the above (7), in the step of raising the temperature, the temperature of the massive body formed of an A×××××× alloy may be raised to a temperature of 600 °C or higher and 620 °C or lower. By raising the temperature of the massive body formed of an A×××××× alloy to a temperature of 600 °C or higher and 620 °C or lower, the ease of causing the impurities to flow out into the liquid phase can be improved.

[0021] (9) In any one of the above (1) to the above (8), the massive body may be formed of pure aluminum or scraps of an aluminum alloy. That is, the method for producing the aluminum raw material is suitable for effectively removing impurities contained in scraps of pure aluminum or an aluminum alloy to obtain an aluminum raw material.

[0022] (1) A method for producing an aluminum material according to an aspect of the present disclosure includes a step of melting an aluminum raw material produced by any one of the above (1) to the above (9) and a step of casting the melted aluminum raw material.

[0023] Since the method for producing the aluminum material melts and casts the aluminum raw material produced by any one of the above (1) to the above (9), an aluminum material with high purity can be obtained.

[0024] [[ID=1⑨]] (11) In the above (10), the method may further include a step of plastically processing the cast aluminum raw material. By plastically processing the cast aluminum raw material, an extruded material made of aluminum with a low concentration of unnecessary components in a desired shape can be obtained.

[0025] Note: In the translation of (4), the specific alloy number "A7075" in the original text is not clear in your description, so I used "A××××××" as a placeholder for translation. You can replace it with the correct alloy number according to the actual situation.(12) A compression apparatus according to one aspect of the present disclosure is an apparatus for compressing a block of aluminum, comprising a heating member for heating the block disposed inside, a pressing member for pressing the heated block, and a heat insulating member disposed between the block and the pressing member.

[0026] In this compression device, an insulating member is placed between the pressing member that presses the heated mass and the mass itself. This suppresses the temperature drop of the mass due to contact with the pressing member, thereby preventing a reduction in the effectiveness of removing impurities from the mass. As a result, this compression device can easily and sufficiently remove impurities from the mass, and a solid phase with reduced impurity concentration can be easily obtained as a high-purity aluminum raw material.

[0027] (12) A pressing apparatus according to one aspect of the present disclosure is a pressing apparatus for pressing a lump of aluminum containing impurities, comprising a heating member for heating the lump and a pressing member for pressing the heated lump, wherein the heating member is configured to heat the pressing member together with the lump.

[0028] In this pressing device, the pressing member that presses the heated mass is heated together with the mass, so the temperature change of the mass being pressed can be suppressed, and the reduction in the effectiveness of removing the impurities from the mass can be suppressed. For this reason, this pressing device can easily and sufficiently remove the impurities from the mass, and a solid phase with a reduced concentration of impurities can be easily obtained as a high-purity aluminum raw material.

[0029] (13) In the above (11) or (12), the compression device may further include a heating unit for heating the pressing member. By including a heating unit for heating the pressing member, the temperature difference between the pressing member and the mass can be easily reduced, and the temperature drop of the mass can be further suppressed.

[0030] (14) The compression device may further include a filtration member on which the lump is placed. By placing the lump on the filtration member and pressing it, the liquid phase can be easily separated from the remainder (solid phase) of the lump.

[0031] [Details of the form for implementing this disclosure] An example of an embodiment of this disclosure will be described in detail below.

[0032] [First Embodiment] One embodiment of the present disclosure is a method for producing aluminum raw material, comprising the steps of: raising the temperature of an aluminum lump containing impurities to a semi-molten state; pressing the heated lump with a pressing member; and recovering the solid phase, from which at least a portion of the liquid phase containing the impurities has been separated by pressing the lump, as aluminum raw material, wherein a heat insulating member is placed between the pressing member and the lump in the pressing step. The method for producing aluminum raw material may be carried out using a compression device 1 as shown in Figure 1.

[0033] <Compression device> The compression device 1 comprises a heating member 12 for heating a mass B placed inside, a pressing member 21 for pressing the heated mass B, and a heat insulating member 30 placed between the mass B and the pressing member 21. Specifically, the compression device 1 comprises a heating unit 10 and a pressing unit 20, with the heating member 12 located in the heating unit 10 and the pressing member 21 located in the pressing unit 20.

[0034] The compression device 1 further comprises a base 50 including a filtration member 40 on which the lump B is placed. The lump B is located inside the pressing unit 20. In this embodiment, the pressing unit 20 and the base 50 are located inside the heating unit 10.

[0035] [Bulky body] The material used for the solid B is not particularly limited as long as it is made from a material containing elements (impurities) that are unwanted during recycling, but it is preferably made from an aluminum-based material. The aluminum-based material may be pure aluminum, or JIS-specified 1000 series alloys, 2000 series alloys, 3000 series alloys, 4000 series alloys, 5000 series alloys, 6000 series alloys, 7000 series alloys, or 8000 series alloys, and may have a component composition suitable for casting or die-casting. The solid B may also be made from scrap of pure aluminum or aluminum alloy. In other words, it may be made from recovered waste materials of pure aluminum or aluminum alloy (such as materials that were discarded unused because they did not meet the product requirements, or materials that were used as products and then discarded). The impurities are not particularly limited as long as they are elements that are not desirable to contain in the desired pure aluminum or aluminum alloy, and examples include eutectic elements such as Cu, Fe, Si, Mn, Co, Ni, Zn, and Mg.

[0036] The shape of the lump B is not particularly limited and may have a regular surface shape such as a sphere or a rectangular parallelepiped, or it may have an irregular surface shape. Furthermore, the lump B may be formed to have an internal space (void) such as a box or a cylindrical body. The lump B is preferably formed in a columnar shape such as a cylindrical shape, a rectangular prism shape, or a polygonal prism shape. When the lump B is formed in a columnar shape and the pressing unit 20 presses on the lump B in the axial direction, a uniform pressing force can be applied to the lump B, improving the ease of efficiently separating the liquid phase.

[0037] [Heating Unit] The heating unit 10 raises the temperature of the mass B, pressing unit 20, filtration member 40, and base 50 housed inside. The heating unit 10 includes a fire-resistant member 11 placed on the floor or ground, a cylindrical heating member 12 placed on the fire-resistant member 11, and a heat-resistant board 13 placed on the heating member 12. The fire-resistant member 11 is not particularly limited and may be, for example, a known firebrick. The heating member 12 is not particularly limited and may be, for example, a known heater. The heat-resistant board 13 is not particularly limited and may be a known heat-resistant board such as one made by mixing a binder with fibrous refractory components mainly composed of Al2O3, SiO2, etc. The heating unit 10 has an internal space composed of the fire-resistant member 11, the heating member 12, and the heat-resistant board 13. A base 50 on which the filtration member 40 is placed is positioned in this internal space, and the aggregate B and the pressing unit 20 are placed on the filtration member 40.

[0038] [Pressing unit] The pressing unit 20 includes a pressing member 21 having a pressing surface 21a for pressing the mass B, a rod 22 connected to the pressing member 21, and a cylindrical sleeve 23 that surrounds the pressing member 21 and the mass B in a plan view. The rod 22 is connected to the opposite side (upper surface) of the pressing surface 21a of the pressing member 21. The rod 22 may be formed integrally with the pressing member 21, or it may be formed separately and fixed to the pressing member 21. A portion of the rod 22 passes through a through hole formed in the heat-resistant board 13 and extends outside the heating unit 10. The rod 22 moves up and down by the operation of a drive device (not shown) to which the above portion is connected. The lowering of the rod 22 causes the pressing member 21 to press the mass B.

[0039] The sleeve 23 is preferably configured to be separable in a direction perpendicular to the axial direction. Specifically, the sleeve 23 may be a half-split shape, for example, configured to be substantially cylindrical by combining a pair of substantially semicircular members. The separable configuration of the sleeve 23 allows for easy removal of the remaining portion (solid phase) of the mass B from which the liquid phase has been separated. The pressing member 21 is positioned to be vertically movable within the sleeve 23.

[0040] It is preferable that a release agent be applied to the inner surface of the sleeve 23. By applying a release agent to the inner surface of the sleeve 23, the pressing member 21 can be easily raised and lowered, and when the solid phase separated from the liquid phase is recovered, it is possible to suppress the adhesion of a part (component) of the sleeve 23 to the solid phase due to contact between the solid phase and the inner surface of the sleeve 23, thereby suppressing a reduction in the purity of the solid phase. The release agent is not particularly limited, and examples include boron nitride and alumina.

[0041] [Insulation materials] The heat insulating member 30 is placed between the mass B and the pressing surface 21a within the sleeve 23, and suppresses the transfer of heat from the heated mass B to the pressing member 21. In other words, the heat insulating member 30 suppresses the pressing member 21 from dissipating heat from the heated mass B. By placing the heat insulating member 30 between the mass B and the pressing member 21, it is possible to suppress the decrease in the temperature of the mass B due to contact with the pressing surface 21a, and thus suppress the reduction in the effect of removing the impurities in the mass B.

[0042] The heat insulating member 30 may be placed on the upper surface of the mass B (the surface that contacts the pressing member 21), but it is preferable to place it on the pressing surface 21a of the pressing member 21. That is, it is preferable that the heat insulating member 30 be fixed to the pressing surface 21a by known means such as adhesive. By fixing the heat insulating member 30 to the pressing surface 21a, the solid phase separated from the liquid phase can be easily recovered.

[0043] The material of the heat insulating member 30 is not particularly limited as long as it can withstand temperatures of 650°C or higher or 700°C or higher. Examples include oxides such as alumina, silica, lime, magnesia, zirconia, chromia, and hematite, and ceramic fibers. The heat insulating member 30 may be formed in the form of a sheet or a plate. The heat insulating member 30 may also be made by layering multiple sheets or plates. Furthermore, the heat insulating member 30 may be a heat-resistant brick, or a combination of materials and shapes. The release agent is not particularly limited and may be the same as the release agent applied to the inner surface of the sleeve 23. The heat insulating member 30 may be coated with a known heat insulating paint.

[0044] The thermal conductivity of the insulating material 30 is preferably 0.10 [W / m·K] or more and 1.0 [W / m·K] or less at 600°C. By setting the thermal conductivity within the above range, it is possible to effectively suppress the decrease in the temperature of the mass B while suppressing an increase in the cost of the insulating material 30.

[0045] The heat insulating material 30 is preferably a porous or cotton-like material having multiple voids. When pressing the mass B, a portion of the heat insulating material 30 may adhere to the solid phase from which the liquid phase has separated. When the solid phase recovered as an aluminum raw material is dissolved, the heat insulating material 30, having multiple voids, tends to float to the surface of the molten metal and can be easily removed from it. The heat insulating material 30 should have a low bulk density to improve the certainty of floating to the molten metal.

[0046] The heat insulating member 30 is preferably arranged in the entire area of ​​the pressing surface 21a that contacts the mass B in a plan view. That is, when viewed in the pressing direction, the heat insulating member 21 is preferably arranged to cover the entire mass B so that the mass B and the pressing surface 21a do not come into contact. By arranging the heat insulating member 21 so that the mass B and the pressing surface 21a do not come into contact, the decrease in the temperature of the mass B can be effectively suppressed. The heat insulating member 21 may also be arranged across the entire surface of the pressing surface 21a. That is, the heat insulating member 30 may be arranged so that the entire pressing surface 21a is covered.

[0047] The lower limit of the ratio of the area on which the heat insulating member 30 is placed to the total area of ​​the pressing surface 21a is preferably 50%, more preferably 60%, and even more preferably 80%. The upper limit of the above ratio is not particularly limited and may be 120% or 100%. By setting the above ratio within the above range, the ease of suppressing heat dissipation from the mass B can be improved.

[0048] A first metal plate may be placed between the pressing member 21 and the heat insulating member 30. Alternatively, a second plate made of pure aluminum coated with a release agent may be placed between the heat insulating member 30 and the mass B, or both the first and second plates may be placed. By placing the first plate, the second plate, or both the first and second plates, the ease of evenly pressing the mass B can be improved.

[0049] [Base] The base 50 is formed as a bottomed cylindrical tank (container), and the filtration member 40 is placed at its opening. By placing the filtration member 40 at the opening of the bottomed cylindrical base 50, the liquid phase dripping from the filtration member 40 can be easily stored inside the base 50.

[0050] The filtration member 40 is placed on the aggregate B and the sleeve 23 of the pressing unit 20. The filtration member 40 drops the liquid phase separated from the solid phase of the aggregate B. Specifically, the filtration member 40 has one or more through holes 41 that penetrate from the surface on which the aggregate B is placed (top surface) to the opposite surface (bottom surface). Alternatively, the filtration member 40 may be formed in a grid shape, a slatted shape, etc. The shape of the through holes 41 is not particularly limited and may be round, rectangular, polygonal, or elongated. The filtration member 40 having through holes 41, or being formed in a grid shape, etc., allows the liquid phase separated from the solid phase of the aggregate B to be easily dropped and separated.

[0051] The material of the filtration member 40 is not particularly limited as long as it can withstand the heat and pressure when the mass B is compressed, and may be, for example, iron or stainless steel.

[0052] It is preferable that a release agent is applied to the filtration member 40. By applying a release agent to the filtration member 40, it is possible to suppress the pressed mass B from adhering to the filtration member 40, and the solid phase separated from the liquid phase can be easily recovered. In addition, it is possible to suppress the adhesion of some (components) of the filtration member 40 to the recovered solid phase, thereby suppressing a reduction in the purity of the solid phase. The release agent is not particularly limited and may be the same as the release agent applied to the inner surface of the sleeve 23.

[0053] A suspension device 60 is preferably placed on the bottom surface of the bottomed cylindrical base 50. The suspension device 60 may have, for example, an engaged portion 61 to which an engaging member (not shown), such as a hook, can engage, a leg portion 62 that supports the engaged portion 61, and a rod-shaped connecting portion 63 that connects the engaged portion 61 and the leg portion 62. The connecting portion 63 may extend upward from the leg portion 62 (in the direction away from the bottom surface) so that the engaged portion 61 is positioned on the surface of the stored liquid phase. The shape of the engaged portion 61 is not particularly limited as long as it is a shape to which an engaging member, such as a hook, can engage, and may be formed in the shape of an annular, inverted U-shape, inverted V-shape, T-shape, etc. By placing the suspension device 60 on the bottom surface of the bottomed cylindrical base 50, the solidified liquid phase can be easily recovered. Specifically, after the liquid phase has solidified, the engaging member is inserted into the base 50 and engaged with the engaged portion 61, and by pulling up the engaging member, the solidified liquid phase together with the suspended device 60 can be easily removed from the base 50. The material of the suspended device 60 is not particularly limited as long as it is heat resistant, and may be, for example, aluminum, stainless steel, or iron. The suspended device does not need to have legs 62 and connecting portion 63 as long as the engaged portion can stand on its own at the bottom surface. The arrangement of a suspended device that cannot stand on its own is not particularly limited as long as it engages with the engaging member and a part of it is below the liquid surface of the liquid phase, and may lean against the side of the base 50, or be suspended from a filtration member 40 or the like.

[0054] <The process of raising the temperature> In the heating step, the aluminum mass B containing impurities is heated to a semi-molten state. The temperature at which the mass B is heated to a semi-molten state may be, for example, a temperature at which the solid phase fraction (weight ratio of solid phase to mass B) of the mass B is 20% or more and 70% or less. The lower limit of the solid phase fraction may be 25% or 30%. The upper limit of the solid phase fraction may be 65% or 60%. By setting the solid phase fraction above the lower limit, a decrease in the recovery rate of the solid phase can be suppressed, and by setting the solid phase fraction below the upper limit, a sufficient liquid phase can be produced, and the impurities can be sufficiently discharged to the liquid phase, effectively reducing the concentration of impurities in the solid phase.

[0055] In the above heating process, if the solid mass is made of A7075 series aluminum alloy, the temperature may be raised to 600°C or higher and 620°C or lower. For solid masses of A7075 series aluminum alloy containing impurities such as Cu and Si, raising the temperature to the above range improves the certainty of achieving a solid fraction of 30% or higher and 70% or lower.

[0056] The lower and upper limits of the solid phase ratio mentioned above may be set as appropriate depending on the purpose. For example, if the concentration of the impurities in the solid phase (aluminum raw material) is to be reduced, the solid phase ratio may be set to 40% or less, or to 35% or less, or to 32% or less. By setting the solid phase ratio within the above range, the concentration of the impurities in the solid phase can be sufficiently reduced. Also, if the recovery rate of the solid phase is to be increased, the solid phase ratio may be set to 50% or more, or to 55% or more, or to 58% or more. By setting the solid phase ratio within the above range, the recovery rate of the solid phase can be sufficiently improved. In this way, the solid phase ratio (temperature at which the temperature is raised) may be adjusted according to the concentration and type of impurities in the aggregate B, the acceptable level of impurity concentration for the intended use of the recovered solid phase, etc.

[0057] The relationship between the temperature at which the material is heated and the solid fraction may be determined, for example, by referring to an equilibrium phase diagram, or by using commercially available thermodynamic calculation software (for example, FactSage from Thermfact Ltd. / CRCT>T-Technologies).

[0058] In the above heating process, it is preferable to also heat the pressing member 21. Heating the pressing member 21 effectively suppresses temperature changes in the compressed mass B. Due to differences in materials, the heating rate of the pressing member 21 may be lower than that of the mass B. In order to bring the temperature of the pressing member 21 closer to that of the mass B, the compression device 1 may be equipped with a heater (not shown) that directly heats the pressing member 21.

[0059] The lump B may be placed on the filter member 40 at room temperature and heated by the heating unit 10 until it reaches a semi-molten state, or it may be heated from room temperature to a predetermined temperature in a heating device (not shown) prepared separately from the compression device 1, and then placed on the filter member 40 and heated by the heating unit 10. That is, the heating step may be performed after the step of placing the lump B on the filter member 40, or the placing step may be performed after the step of heating the lump B to a predetermined temperature, followed by the heating step. The predetermined temperature may be the temperature at which the lump B reaches a semi-molten state. In the placing step described above, another member (intermediate member) may be placed between the filter member 40 and the lump B. By placing an intermediate member between the filter member 40 and the lump B, it is possible to suppress the adhesion of a part (component) of the filter member 40 to the lump B. The intermediate member may be made of the same material as the heat insulating member 30.

[0060] <Pressing process> In the pressing step, the heated mass B is pressed with the pressing member 21. Specifically, the heated mass B is pressed with the pressing member 21 of the pressing unit 20 in the compression device 1, separating the mass B into a liquid phase containing at least some of the impurities and a solid phase with a reduced concentration of the impurities. In this pressing step, a heat insulating member 30 (first heat insulating member) is placed between the pressing member 21 that presses the mass B in the compression device 1 and the mass B. The heat insulating member 30 only needs to be placed when the mass B is pressed, and may be placed immediately before the pressing member 21 and the mass B come into contact, but it is preferable that it be placed before the pressing step. The heat insulating member 30 may be heated before or after it is placed. By preheating the heat insulating member 30 before pressing, the temperature drop of the mass B during pressing can be further suppressed.

[0061] In the method for manufacturing the aluminum raw material, a heat insulating member 30 is placed between the pressing member 21 that presses the lump B and the lump B. This suppresses the temperature drop caused by contact between the lump B and the pressing member 21, and prevents a reduction in the effect of removing the impurities from the pressed lump B.

[0062] The temperature change of the mass B due to contact with the heat insulating member 30 is preferably less than ±20°C, more preferably less than ±15°C, and even more preferably less than ±10°C. By keeping the temperature change within the above range, the certainty of suppressing the reduction of the impurity emission effect can be improved. The temperature of the mass B may be measured by placing a known thermometer such as a thermocouple inside the mass B.

[0063] The upper limit of the pressing force applied to the mass B in the pressing process described above is preferably 2.0 MPa. The lower limit of the pressing force is not particularly limited and may be, for example, 0.1 MPa or 0.3 MPa. By setting the pressing force within the above range, it is possible to improve the reliability of separating the liquid phase from the mass B while suppressing damage to the compression device 1.

[0064] In this method for producing the aluminum raw material, a lump B is placed on the filter member 40 and pressed to separate the liquid phase, so that the separated liquid phase passes through the filter member 40 and is stored in the base 50. Therefore, unlike the conventional technique, there is no need to solidify the liquid phase and cut the solidified portion, and the liquid phase can be easily separated. Furthermore, since the lump B is placed inside the sleeve 23 and pressed, the separated liquid phase is guided in a direction that passes through the filter member 40, improving the certainty of the separation of the liquid phase from the solid phase and easily improving the purity of the solid phase.

[0065] <Recovery process> In the recovery process, the solid phase, which separates the liquid phase containing at least some of the impurities by pressing the lump B, is recovered as aluminum raw material. The solid phase can be recovered by dividing the split-shaped sleeve 23.

[0066] In the recovery process described above, the liquid phase may also be recovered. The recovery of the liquid phase is preferably done by solidifying the liquid phase and then engaging the engaging member with the suspension device 60 located on the bottom surface of the bottomed cylindrical base 50 to pick it up. The recovery of the liquid phase may be performed after the heating process and the pressing process described above have been performed on multiple lumps.

[0067] The lower limit of the removal rate of the impurities in the solid phase is preferably 40%, and more preferably 45%. The upper limit of the removal rate is not particularly limited and may be, for example, 90%, 75%, or 60%. By setting the removal rate within the above range, the production efficiency of high-purity aluminum raw materials can be improved. The removal rate is a value calculated from the following formula 1. Note that "the removal rate of the impurities in the solid phase" means the ratio of the impurities contained in the solid phase to the impurities contained in the aggregate B. (B E -S E ) / B E ...(1) Here, B E This refers to the content [mass%] of impurity elements in the initial mass before the impurity removal treatment described above, and S EThis refers to the content [mass%] of impurity elements in the recovered solid phase.

[0068] The solidified liquid phase may be treated as a mass of aluminum containing impurities, and the aluminum raw material may be manufactured using this method. That is, the solidified liquid phase may be subjected to the heating step, the pressing step, and the recovery step, and a solid phase with the impurities reduced from the liquid phase may be recovered as the aluminum raw material. Before the heating step, it is advisable to take a sample from the liquid phase and analyze its components. By analyzing the components of the liquid phase, the heating temperature in the heating step and the pressing force in the pressing step can be easily determined.

[0069] [Method for manufacturing aluminum material] The method for manufacturing the aluminum material comprises the steps of melting the aluminum raw material (solid phase) produced by the method for manufacturing the aluminum raw material, and casting the melted aluminum raw material. Since the impurity concentration of the aluminum raw material is reduced, a high-purity aluminum material can be obtained by melting and casting it. In the melting step, pure aluminum ingots and one or more alloying elements may be melted together with the aluminum raw material.

[0070] The method for manufacturing the aluminum material may further include a step of plastically deforming the cast aluminum raw material. By plastically deforming the cast aluminum raw material, a wrought material made of aluminum with a low concentration of unwanted components and a desired shape can be obtained.

[0071] [Second Embodiment] The following describes another embodiment of the method for manufacturing the aluminum raw material. The same process as described above for manufacturing the aluminum raw material, and the same components (parts) as described above for the pressing apparatus, will not be explained.

[0072] The method for producing the aluminum raw material comprises the steps of: raising the temperature of an aluminum lump containing impurities to a semi-molten state; pressing the heated lump with a compression device; and recovering the solid phase, from which at least some of the impurities have been separated by pressing the lump, as the aluminum raw material, wherein in the heating step, the pressing member that presses the lump in the compression device is heated.

[0073] <Compression device> The pressing device used in the method for manufacturing the aluminum raw material comprises a heating unit for heating a lump and a pressing unit for pressing the heated lump, wherein the pressing unit includes a pressing member for pressing the lump, and the heating unit heats the pressing member together with the lump. The pressing device further comprises a filtration member on which the lump is placed and a base on which the filtration member is placed. The pressing unit, the filtration member and the base are arranged within the heating unit, and the lump is placed within the pressing unit. The heating unit, the filtration member and the base may be the heating unit 10, the filtration member 40 and the base 50 described above. The pressing device does not include an insulating member 30.

[0074] The pressing unit includes a pressing member having a pressing surface for pressing the lump, a rod connected to the pressing member, and a cylindrical sleeve that surrounds the pressing member and the lump in a plan view. The rod is connected to the opposite side (upper surface) of the pressing surface on the pressing member. A portion of the rod passes through a through hole formed in the heat-resistant board of the heating unit and extends outside the heating unit. The rod moves up and down by the operation of the drive device to which the portion is connected. The lowering of the rod causes the pressing member to press the lump.

[0075] <The process of raising the temperature> In the heating process, the mass is heated to a semi-molten state, and the pressing member is also heated. The pressing member is preferably heated so that its pressing surface is at approximately the same temperature as the mass. By heating the pressing surface to approximately the same temperature as the mass, the temperature drop of the mass due to contact with the pressing member can be suppressed. The pressing member is preferably heated by a heating element of a heating unit. The pressing member may also be heated by a heating device prepared separately from the compression device.

[0076] The temperature difference between the heated mass and the pressing member is preferably within 100°C, more preferably within 50°C, and even more preferably within 30°C. By keeping the temperature difference within this range, the liquid phase can be efficiently seeped out of the mass and separated.

[0077] The above-mentioned compression device may be equipped with a first heater for heating the pressing member. By providing the above-mentioned compression device with the first heater, the ease of bringing the pressing member to the above-mentioned temperature range can be improved. The above-mentioned first heater may be placed, for example, on the opposite side of the pressing surface of the pressing member. The above-mentioned compression device may further be equipped with a second heater for heating the rod. By providing the above-mentioned compression device with a second heater for heating the rod, the temperature drop of the pressing member can be suppressed, and the temperature drop of the mass can be further suppressed.

[0078] The temperature change of the mass due to contact with the pressing member is preferably less than ±20°C, more preferably less than ±15°C, and even more preferably less than ±10°C. By keeping the temperature change within this range, the certainty of suppressing the reduction in the impurity removal effect can be improved.

[0079] [Other embodiments] The above embodiments do not limit the configuration of the present invention. Accordingly, the above embodiments allow for the omission, substitution, or addition of components of each part of the above embodiments based on the description herein and common technical knowledge, and all such omissions, substitutions, or additions should be interpreted as falling within the scope of the present invention.

[0080] The heating unit is not limited to the above configuration as long as it can heat up a solid mass. For example, a heating device such as a heater may be placed on the outer surface of the sleeve of the pressing unit to heat the inside of the sleeve.

[0081] To improve the heat dissipation suppression effect of the mass, an insulating paint may be applied to the pressing surface of the pressing member. [Examples]

[0082] The present disclosure will be further illustrated below with reference to examples, but the present disclosure is not limited to these examples.

[0083] As a test example, a lump of A7075 aluminum alloy containing impurities such as Cu and Si was prepared and compressed using the compression device 1 shown in Figure 1. The lump was placed on a filtration member 40, which had a release agent (boron nitride) applied to it and had slit-shaped through holes formed therein. The filtration member 40 was placed on a bottomed cylindrical base 50. As an insulating member 30, two layers of sheet-like insulating material BSSR 1200 blanket 130 (manufactured by Isolite Industries Co., Ltd.: thermal conductivity of 0.18 [W / m·K] at 600℃) were placed over the entire surface of the pressing surface 21a. In addition, to ensure uniform compression of the lump, a pure aluminum plate with a release agent applied to its upper surface was placed between the lump and the insulating member 30. The lump was heated to 620℃ (solid fraction of 30% according to thermodynamic calculations) and compressed. After the compression was completed, the heating unit was stopped to allow the liquid phase stored in the base 50 to solidify. The remaining solid phase of the mass after the liquid phase was separated and the solidified liquid phase were recovered. Figure 2 shows the results of the temperature change of the mass measured by placing a thermocouple inside the mass.

[0084] As a comparative example, compression was performed under the same conditions as the test example, except that the heat insulating material 30 was not used. Figure 3 shows the temperature change of the aggregate in this comparative example. The Cu and Si concentrations of the aggregates from the test example and comparative example, as well as the solid and liquid phases recovered, were analyzed by ICP emission spectrometry. The results are shown in Table 1.

[0085] [Table 1]

[0086] As shown in Figure 2, in the test example where the heat insulating member 30 was placed, no temperature drop was observed in the mass B at the start of compression, and compression was achieved at the desired temperature (approximately 620°C). As shown in Figure 3, in the comparative example where the heat insulating member was not placed, the temperature of the mass dropped to below 600°C at the moment the pressing surface of the pressing member came into contact with the mass, and compression at the desired temperature was not possible.

[0087] Table 1 compares the concentrations of impurity elements (Cu and Si) in the solid phase of the test example where the temperature of the mass did not decrease during compression, and in the solid phase of the comparative example where the temperature of the mass decreased during compression. It can be seen that the solid phase of the test example had lower concentrations than the solid phase of the comparative example, indicating that it was a higher-purity aluminum raw material. From this, it can be seen that even without using an insulating material, if the pressing member is preheated to prevent a decrease in the temperature of the mass during compression, a high-purity aluminum raw material can be obtained, similar to the case where the insulating material 30 is used. [Industrial applicability]

[0088] The method for producing aluminum raw materials described herein is particularly suitable for recycling aluminum and aluminum alloys because it can obtain aluminum raw materials with reduced impurities from aluminum ingots containing impurities. [Explanation of Symbols]

[0089] 1. Compression device 10. Heating Unit 11 Fire-resistant materials 12 Heating element 13 Heat-resistant board 20 Pressing Units 21 Pressing member 21a Pressing surface 22 rods 23 sleeves 30 Insulation material 40 Filter components 41 Through hole 50 abutments 60 Lifting Gear 61. The unit of connection 62. Feet 63 Jiebu B. Block

Claims

1. A process of raising the temperature of an aluminum block containing impurities until it reaches a semi-molten state, A step of pressing the heated mass with a pressing member, A step of recovering the solid phase, from which the liquid phase containing at least some of the impurities has been separated by pressing the above-mentioned mass, as an aluminum raw material. Equipped with, A method for manufacturing aluminum raw material, wherein a heat insulating member is placed between the pressing member and the mass in the pressing step described above.

2. The method for manufacturing aluminum raw material according to claim 1, wherein, in a plan view, the heat insulating member is arranged over the entire area in which the mass-like body of the pressing member makes contact.

3. The method for producing an aluminum raw material according to claim 1, wherein the above-mentioned heat insulating material is a porous body or cotton-like body having a plurality of voids.

4. The method for producing aluminum raw material according to claim 1, wherein in the pressing step described above, the mass is pressed with the heated pressing member.

5. A process of raising the temperature of an aluminum block containing impurities until it reaches a semi-molten state, A step of pressing the heated mass with a pressing member, A step of recovering the solid phase, from which the liquid phase containing at least some of the impurities has been separated by pressing the above-mentioned mass, as an aluminum raw material. Equipped with, A method for manufacturing aluminum raw material, comprising heating the pressing member in the above heating step.

6. A method for producing an aluminum raw material according to claim 1 or claim 5, further comprising the step of placing the above-mentioned lump-shaped body on a filter member.

7. The method for producing an aluminum raw material according to claim 6, wherein a release agent is applied to the above-mentioned filter member.

8. A method for producing an aluminum raw material according to claim 1 or claim 5, wherein in the above heating step, the mass, which is made of A7075 series aluminum alloy, is heated to a temperature of 600°C or more and 620°C or less.

9. A method for producing an aluminum raw material according to claim 1 or claim 5, wherein the above-mentioned mass is formed from pure aluminum or aluminum alloy scrap.

10. A step of dissolving the aluminum raw material produced by the manufacturing method described in claim 1 or claim 5, The process of casting the molten aluminum raw material and A method for manufacturing aluminum material, comprising the features described above.

11. The method for producing an aluminum material according to claim 10, further comprising a step of plastically processing the cast aluminum raw material.

12. An apparatus for compressing a block of aluminum containing impurities, A heating member that raises the temperature of the above-mentioned mass placed inside so that it becomes semi-molten, A pressing member for pressing the heated mass, A heat insulating member is placed between the above-mentioned mass and the above-mentioned pressing member. A compression device equipped with the following features.

13. A device for compressing a block of aluminum containing impurities, A heating member that raises the temperature of the above-mentioned mass placed inside so that it becomes semi-molten, A pressing member that presses the heated mass and Equipped with, A compression device in which the above-mentioned heating member is configured to heat the above-mentioned pressing member together with the above-mentioned mass.

14. The compression device according to claim 12 or claim 13, further comprising a heating unit for heating the pressing member.

15. The compression device according to claim 12 or claim 13, further comprising a filtration member on which a lump-shaped body is placed.

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