Preparation device of rare earth aluminum intermediate alloy

Abstract

The utility model relates to the technical field of metal manufacturing equipment, and provides a rare earth aluminum intermediate alloy preparation device which comprises a tundish and a horizontally-arranged cooling roller, and the tundish is arranged over the cooling roller; the tundish comprises a containing cavity with the open top face, a filtering element and a sprue gate. The filtering element is arranged in the accommodating cavity; the sprue gate is embedded in a bottom opening of the accommodating cavity, and the width of the sprue gate is 3-8 mm; and the distance between the sprue gate and the surface of the cooling roller is 10-30 mm. The aluminum-scandium intermediate alloy prepared by the device is uniform in scandium distribution, and the segregation rate can be controlled within + / -0.1%; moreover, the device not only can avoid the risk that the cooled metal sheet is clamped between the cooling roller and the sprue gate, but also can prevent the alloy liquid flowing out of the sprue gate from being oxidized due to contact with air, and can prevent the alloy liquid from splashing caused by dropping onto the cooling roller.

Description

Technical Field

[0001] The utility model relates to the technical field of metal manufacturing equipment, and particularly relates to a device for preparing rare earth aluminum master alloy. Background Art

[0002] The existing preparation processes of aluminum scandium master alloy include the doping method, the electrolysis method, and the aluminothermic reduction method. The cooling methods of aluminum scandium master alloy are commonly prepared by equipment such as air cooling and water-cooled mold casting. The prepared aluminum scandium alloy has the problem of uneven distribution of scandium content, that is, serious segregation. Summary of the Utility Model

[0003] In order to overcome the defects of uneven distribution of rare earth elements and high segregation rate in the rare earth aluminum master alloy prepared by known devices or equipment in the prior art, a device for preparing aluminum scandium master alloy is provided; the scandium distribution of the aluminum scandium master alloy prepared by this device is uniform, and the segregation rate can be controlled within ±0.1%; moreover, this device can avoid the risk of "cooled metal sheets getting stuck between the cooling roller and the pouring port", prevent the alloy liquid flowing out of the pouring port from contacting the air and being oxidized, and prevent the splashing caused by the alloy liquid dripping onto the cooling roller. The present application provides a device for preparing rare earth aluminum master alloy.

[0004] A device for preparing rare earth aluminum master alloy provided by the present application adopts the following technical scheme:

[0005] A device for preparing rare earth aluminum master alloy includes a tundish and a horizontally arranged cooling roller, and the tundish is arranged directly above the cooling roller;

[0006] Wherein, the tundish includes a receiving cavity with an open top surface, a filtering element, and a pouring port; the filtering element is arranged inside the receiving cavity; the pouring port is embedded at the bottom opening of the receiving cavity, and the width of the pouring port is 3 - 8 mm; the distance between the pouring port and the surface of the cooling roller is 10 - 30 mm.

[0007] In the present utility model, during the pouring process of using the device for preparing rare earth aluminum master alloy, the impact of the rare earth aluminum alloy liquid on the cooling roller is slowed down, so as to form a stable alloy liquid stream and uniformly flow onto the cooling roller; and it can avoid the segregation of the alloy liquid due to excessive temperature drop before contacting the cooling roller; in addition, the residual salt slag in the alloy liquid can be removed to prevent the salt slag from blocking the pouring port.

[0008] In the present utility model, the width of the pouring gate refers to the dimension of the pouring gate along the radial direction of the cooling roll. Within the width range of the above-mentioned pouring gate, the alloy liquid can stably flow from the pouring gate to the cooling roll for cooling; when the width of the pouring gate is too small, it is prone to blockage, while when the width of the pouring gate is too large, the pouring speed will be too fast, causing the alloy liquid to not be quickly cooled on the cooling roll and directly flow into the receiving unit of the alloy sheet, thereby causing segregation.

[0009] In some embodiments, the interior of the cooling roll is hollow for the circulation of the cooling medium.

[0010] In some embodiments, the material of the cooling roll is copper.

[0011] In the present utility model, the size of the cooling roll can be determined according to the actual furnace loading amount in practical applications and the pouring speed during the process.

[0012] In some embodiments, the diameter of the cooling roll is 200 - 400 mm.

[0013] In some embodiments, the length of the cooling roll is 150 - 300 mm.

[0014] In a certain embodiment, the diameter and length of the cooling roll are 300 mm and 200 mm respectively.

[0015] In the present utility model, during the preparation of rare earth aluminum master alloy using the preparation device, the cooling water temperature in the hollow part of the cooling roll is < 30 °C, and the rotation speed of the cooling roll is 100 - 200 r / min.

[0016] In a certain embodiment, the size of the tundish is 200 mm * 200 mm * 150 mm.

[0017] In some embodiments, the tundish further includes a shell, the shell is disposed on the outer wall surface of the accommodating cavity, and an opening is provided at the bottom of the shell to enable the pouring gate to pass through the shell; the shell is used to support the accommodating cavity.

[0018] In a specific embodiment, the shell is a cuboid; the wall thickness of the shell is 2 - 5 mm; within the wall thickness range of the shell, the shell is both lightweight and has sufficient mechanical strength.

[0019] In a specific embodiment, the material of the shell is steel.

[0020] In some embodiments, the accommodating cavity is a cuboid.

[0021] In some embodiments, the receiving cavity is divided into an upper chamber and a lower chamber by the filter element; the longitudinal section of the upper chamber is rectangular; the longitudinal section of the lower chamber is rectangular or trapezoidal with a wider upper part and a narrower lower part.

[0022] In some embodiments, the receiving cavity is made of mullite.

[0023] In some embodiments, the filter element is made of zirconia foam ceramics or alumina foam ceramics.

[0024] In some embodiments, the filter element is in a sheet shape.

[0025] In some embodiments, the thickness of the filter element is 10 - 20 mm.

[0026] In a specific embodiment, the length and width of the filter element are both 160 mm.

[0027] In some embodiments, the porosity of the filter element is 80% - 90%.

[0028] In some embodiments, the pore density of the filter element is 8 - 60 ppi, where ppi refers to the number of holes per unit inch.

[0029] In some embodiments, a limiting portion is provided in a ring shape on the inner wall surface of the receiving cavity for supporting the filter element.

[0030] In some embodiments, the material of the pouring gate is graphite or silicon carbide.

[0031] In some embodiments, the length of the pouring gate is 40 - 100 mm.

[0032] In a certain embodiment, the length, width, and height of the pouring gate are 50 mm, 3 mm, and 20 mm respectively.

[0033] In some embodiments, the preparation device further includes a receiving hopper; the opening side of the receiving hopper faces the cooling roller.

[0034] In some embodiments, the preparation device further includes a motor and a belt; the motor is connected to a pulley provided at one end of the cooling roller through the belt for driving the cooling roller to rotate; the motor is a variable-frequency motor; the belt drives the cooling roller to rotate through the motor.

[0035] In some embodiments, the preparation device for the rare earth aluminum master alloy is used to prepare aluminum scandium master alloy.

[0036] In some embodiments, the preparation device for the rare earth aluminum master alloy is the preparation device for aluminum scandium master alloy.

[0037] In the present utility model, using the preparation device as described above, the steps for preparing the aluminum scandium master alloy include: pouring the heat-insulated aluminum scandium alloy liquid from the crucible into the tundish for casting; guiding the aluminum scandium alloy liquid through the tundish to the cooling roll for cooling, and collecting the alloy sheets that are cooled and solidified into strips; then pressing the alloy sheets into blocks by a hydraulic press to obtain block-shaped alloy ingots.

[0038] Among them, the casting temperature is 850 - 950 °C, and the casting speed is 0.2 - 0.3 L / s.

[0039] In summary, the present application includes the following beneficial technical effects:

[0040] 1. Before the present utility model, existing devices generally cooled through air cooling or water cooling molds to prepare rare earth aluminum master alloys. The prepared rare earth aluminum master alloys (especially aluminum scandium master alloys) have a relatively high segregation rate; while the scandium in the aluminum scandium master alloy prepared by using the preparation device of the present application is evenly distributed, and the segregation rate can be controlled within ±0.1%.

[0041] 2. Through the structural design of the preparation device for rare earth aluminum master alloys of the present application, it is possible to avoid the risk of "the cooled metal sheet getting stuck between the cooling roll and the casting port", prevent the alloy liquid flowing out of the casting port from contacting the air and being oxidized, and prevent the splashing caused by the alloy liquid dripping onto the cooling roll. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other embodiments can be obtained based on these drawings.

[0043] In the figures:

[0044] Figure 1 is a schematic structural diagram of the preparation device for rare earth aluminum master alloy in Embodiment 1;

[0045] Figure 2 is an exploded schematic structural diagram of the tundish in Embodiment 1;

[0046] Figure 3 is a left view of the tundish in Embodiment 1;

[0047] Figure 4 is a front view of the tundish in Embodiment 1.

[0048] Reference numerals: 1 tundish; 2 cooling roll; 3 motor; 4 receiving hopper; 5 filter element; 6 receiving cavity; 7 pouring port; 8 housing. Detailed implementation mode

[0049] The following further elaborates on this application in conjunction with the attached Figures 1-4 drawings.

[0050] Embodiment 1:

[0051] This embodiment discloses a preparation device for rare earth aluminum master alloy. Figure 1 is a schematic structural diagram of the preparation device for rare earth aluminum master alloy in this embodiment.

[0052] The preparation device for rare earth aluminum master alloy includes a tundish 1 and a horizontally arranged cooling roll 2, and the tundish 1 is arranged directly above the cooling roll 2;

[0053] Figure 2 is a schematic exploded view of the structure of the tundish in this embodiment. The tundish 1 includes a receiving cavity 6 with an open top surface, a filter element 5, and a pouring port 7; the filter element 5 is arranged inside the receiving cavity 6; the pouring port 7 is embedded at the bottom opening of the receiving cavity 6, and the length, width, and height of the pouring port 7 are 50 mm, 3 mm, and 20 mm respectively; the distance between the pouring port 7 and the surface of the cooling roll 2 is 15 mm.

[0054] Among them, the inside of the cooling roll 2 is hollow for the circulation of the cooling medium, its material is copper, and the diameter and length of the cooling roll 2 are 300 mm and 200 mm respectively.

[0055] Figure 3 is a left view of the tundish in this embodiment; Figure 4 is a front view of the tundish in this embodiment.

[0056] Among them, the size of the tundish 1 is 200 mm * 200 mm * 150 mm; the tundish 1 further includes a housing 8, the housing 8 is arranged on the outer wall surface of the receiving cavity 6, and the bottom of the housing 8 is provided with an opening to enable the pouring port 7 to pass through the housing 8; the housing 8 is used to support the receiving cavity 6; the housing 8 is a cuboid, its wall thickness is 2 mm, and the material is steel.

[0057] Among them, the receiving cavity 6 is a cuboid; the receiving cavity 6 is divided into an upper chamber and a lower chamber by the filter element 5; the upper chamber is a cuboid structure; the lower chamber is a frustum structure; the material of the receiving cavity 6 is mullite.

[0058] Among them, the filtering element 5 is made of zirconia foam ceramics; the filtering element 5 is in sheet form; the size of the filtering element 5 is 160 mm * 160 mm * 10 mm; the porosity of the filtering element 5 is 80% - 90%; the pore density of the filtering element 5 is 8 - 60 ppi, where ppi refers to the number of holes per unit inch; the inner wall surface of the accommodating cavity 6 is provided with a limiting portion for supporting the filtering element 5.

[0059] Among them, the pouring gate 7 is made of graphite or silicon carbide; the length, width, and height of the pouring gate 7 are 50 mm, 3 mm, and 20 mm respectively.

[0060] Among them, the preparation device further includes a receiving hopper 4; the opening side of the receiving hopper 4 faces the cooling roller 2.

[0061] Among them, the preparation device further includes a motor 3 and a belt; the motor 3 is connected to a pulley provided at one end of the cooling roller 2 through the belt for driving the cooling roller 2 to rotate; the motor 3 is a variable-frequency motor 3; the belt drives the cooling roller 2 to rotate through the motor 3.

[0062] This embodiment also discloses a method for preparing aluminum scandium master alloy, including the following steps:

[0063] (1) Weigh 15 kg of aluminum ingots, 0.75 kg of scandium fluoride, 0.15 kg of scandium oxide, 0.6 kg of sodium fluoride and other materials, and their mass ratio is 1:0.05:0.01:0.04;

[0064] (2) Add the aluminum ingots into the graphite crucible of the intermediate frequency induction furnace;

[0065] (3) Heat to 980 °C, add scandium fluoride, scandium oxide, and sodium fluoride, and the salt slag melts. Keep it at 980 °C for 40 minutes, and stir the materials evenly with a graphite rod every 10 minutes during this period;

[0066] (4) After the heat preservation ends, stop heating. Wait until the temperature drops to 900 °C, remove the salt slag on the surface of the crucible with tools, and use the above-mentioned preparation device for the remaining alloy liquid to prepare aluminum scandium master alloy;

[0067] (5) Pour the alloy liquid obtained in step (4) into the tundish 1. The pouring temperature is 850 - 950 °C, and the pouring speed is 0.2 L / s. It flows from the pouring gate 7 of the tundish 1 onto the rotating water-cooled copper roller with a rotation speed of 150 r / min, and a strip-shaped aluminum scandium master alloy sheet is obtained after cooling;

[0068] Among them, the temperature of the cooling water in the hollow part of the cooling roller 2 is < 30 °C, and the rotation speed of the cooling roller 2 is 100 - 200 r / min;

[0069] (6) Extrude the strip-shaped aluminum scandium master alloy sheet into blocks by a briquetting machine to obtain block-shaped aluminum scandium master alloy.

[0070] Comparative Example 1:

[0071] This comparative example also discloses a preparation device and a preparation method for aluminum scandium master alloy.

[0072] The preparation device is a water-cooled mold, which includes a water-cooled plate. There is circulating cooling water inside the water-cooled plate, and a cavity for holding the molten alloy is provided on the water-cooled plate.

[0073] The preparation method includes the following steps:

[0074] (1) Weigh 15 kg of aluminum ingots, 0.75 kg of scandium fluoride, 0.15 kg of scandium oxide, 0.6 kg of sodium fluoride and other materials, and their mass ratio is 1:0.05:0.01:0.04;

[0075] (2) Add the aluminum ingots into the graphite crucible of the intermediate frequency induction furnace;

[0076] (3) Heat to 980 °C, add scandium fluoride, scandium oxide, and sodium fluoride. The salt slag melts and is kept at 980 °C for 40 minutes. During this period, stir the materials evenly with a graphite rod every 10 minutes;

[0077] (4) After the heat preservation ends, stop heating. When the temperature drops to 900 °C, scoop out the salt slag on the surface of the molten pool with tools;

[0078] (5) Pour the molten alloy into the cavity on the water-cooled plate, and after cooling, obtain an aluminum scandium master alloy ingot;

[0079] (6) Extrude the flaky aluminum scandium master alloy into blocks with a briquetting machine to obtain a blocky aluminum scandium master alloy.

[0080] Comparative Example 2:

[0081] This comparative example also discloses a preparation device and a preparation method for aluminum scandium master alloy.

[0082] The preparation device belongs to a cast iron mold, which includes a cooling plate. There are several cavities for holding the molten alloy on the cooling plate.

[0083] The preparation method includes the following steps:

[0084] (1) Weigh 15 kg of aluminum ingots, 0.75 kg of scandium fluoride, 0.15 kg of scandium oxide, 0.6 kg of sodium fluoride and other materials, and their mass ratio is 1:0.05:0.01:0.04;

[0085] (2) Add the aluminum ingots into the graphite crucible of the intermediate frequency induction furnace;

[0086] (3) Heat to 980 °C, add scandium fluoride, scandium oxide, and sodium fluoride. The salt slag melts and is kept at 980 °C for 40 min. During this period, stir the materials evenly with a graphite rod every 10 min;

[0087] (4) After the heat preservation ends, stop heating. Wait until the temperature drops to 900 °C, and then use tools to fish out the salt slag on the surface of the molten pool;

[0088] (5) Pour the alloy liquid into the cavity of the cooling plate, and cool the alloy liquid through air to obtain an aluminum-scandium master alloy ingot.

[0089] Effect Example 1:

[0090] This effect example analyzes the segregation degree of the aluminum-scandium master alloy ingots prepared in Example 1 and Comparative Examples 1-2.

[0091] Samples are taken at six different positions of the aluminum-scandium master alloy in the examples and comparative examples, and the scandium content is measured using the EDTA titration method. Table 1 shows the detection results of the scandium content in the samples of Example 1 and Comparative Examples 1 and 2. Among them, the range is the difference between the highest and lowest values of the sampling points, and ±(range value / 2) represents the segregation degree:

[0092] Table 1:

[0093]

[0094] Compared with Example 1, the deviation of the sampling point results in Comparative Examples 1 and 2 is ±0.27% and ±1.35% respectively, and the segregation is relatively serious. However, using the preparation device of the present application can effectively reduce the segregation of the scandium content, and the segregation degree can be controlled within ±0.1%.

[0095] The above are the exemplary embodiments disclosed by the present utility model. However, it should be noted that various changes and modifications can be made without departing from the scope of the embodiments disclosed by the present utility model as defined by the claims. The functions, steps, and / or actions of the method claims according to the disclosed embodiments herein do not need to be executed in any specific order. In addition, although the elements disclosed in the embodiments of the present utility model can be described or claimed in an individual form, they can also be understood as plural unless explicitly limited to the singular.

[0096] It should be understood that, as used herein, unless the context clearly supports an exception, the singular form "a" is also intended to include the plural form. It should also be understood that the "and / or" used herein means any and all possible combinations including one or more of the associated listed items. The serial numbers of the disclosed embodiments of the present utility model above are only for description and do not represent the advantages or disadvantages of the embodiments.

[0097] Those of ordinary skill in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope (including the claims) disclosed by the embodiments of the present invention is limited to these examples; under the concept of the embodiments of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and there are many other variations in different aspects of the embodiments of the present invention as described above, which are not provided in detail for the sake of brevity. Therefore, any omission, modification, equivalent replacement, improvement, etc. made within the spirit and principle of the embodiments of the present invention shall be included in the protection scope of the embodiments of the present invention.

Claims

1. A preparation device for rare earth aluminum master alloy, characterized in that: It comprises a tundish and a horizontally arranged cooling roller, wherein the tundish is arranged directly above the cooling roller; The tundish comprises a accommodating cavity with an open top surface, a filter element and a pouring gate; the filter element is arranged inside the accommodating cavity; the pouring gate is embedded in the bottom opening of the accommodating cavity, and the width of the pouring gate is 3-8 mm; the distance between the pouring gate and the surface of the cooling roller is 10-30 mm.

2. The device for preparing a rare earth aluminum master alloy according to claim 1, characterized in that: The cooling roller meets one or more of the following conditions: ① The interior of the cooling roller is hollow for the circulation of cooling medium; ② The cooling roller is made of copper; ③The diameter of the cooling roller is 200-400mm; ④The length of the cooling roller is 150-300mm.

3. The device for preparing a rare earth aluminum master alloy according to claim 1, characterized in that: The tundish further comprises a shell, which is arranged on the outer wall of the accommodating cavity, and an opening is arranged at the bottom of the shell so that the pouring port passes through the shell; The shell is a cuboid; The wall thickness of the shell is 2-5 mm; The shell is made of steel.

4. The device for preparing a rare earth aluminum master alloy according to claim 1, characterized in that: The accommodating cavity meets one or more of the following conditions: ① The accommodating cavity is a rectangular parallelepiped; ② The accommodating chamber is divided into an upper chamber and a lower chamber by the filter element; the longitudinal section of the upper chamber is a rectangle; the longitudinal section of the lower chamber is a rectangle or a trapezoid that is wide at the top and narrow at the bottom; ③The material of the accommodating cavity is mullite.

5. The device for preparing a rare earth aluminum master alloy according to claim 1, characterized in that: The filter element meets one or more of the following conditions: ① The material of the filter element is zirconium oxide foam ceramic or aluminum oxide foam ceramic; ② The filter element is in sheet form; ③The porosity of the filter element is 80%-90%; ④ The pore density of the filter element is 8-60ppi, where ppi refers to the number of holes per unit inch.

6. The device for preparing a rare earth aluminum master alloy according to claim 1, characterized in that: The inner wall surface of the accommodating cavity is provided with a limiting portion for supporting the filter element.

7. The device for preparing a rare earth aluminum master alloy according to claim 1, characterized in that: The pouring nozzle meets one or both of the following conditions: ① The material of the pouring port is graphite or silicon carbide; ②The length of the pouring port is 40-100mm.

8. The device for preparing a rare earth aluminum master alloy according to claim 1, characterized in that: The preparation device also includes a receiving hopper; the opening side of the receiving hopper is arranged toward the cooling roller.

9. The device for preparing a rare earth aluminum master alloy according to claim 1, characterized in that: The preparation device also includes a motor and a belt; the motor is connected to a pulley arranged at one end of the cooling roller through the belt to drive the cooling roller to rotate; the motor is a variable frequency motor.

10. A device for preparing a rare earth aluminum master alloy according to any one of claims 1 to 9, characterized in that: The device for preparing the rare earth aluminum master alloy is a device for preparing the aluminum-scandium master alloy.

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