Rare earth metal casting mold

Abstract

The utility model discloses a rare earth metal casting mold which is of a containing groove structure with an upper opening. The containing groove structure comprises a bottom wall and a side wall, the bottom wall and the side wall define the containing groove structure, and a containing space of the containing groove structure is used for containing a rare earth metal melt and enabling the rare earth metal melt to form a rare earth metal block in a corresponding shape; a first cavity is formed in the bottom wall, and a second cavity is formed in the side wall; the first cavity is communicated with the second cavity; and the accommodating space is not communicated with the first cavity and the second cavity. The mold can slow down the cooling and solidification speed of the rare earth metal melt, so that electrolyte impurities in the rare earth metal melt fully float on the surface, the separation of slag formed by the electrolyte from the rare earth metal in the subsequent process is facilitated, the purity of the rare earth metal product is improved, the loss of the rare earth metal is reduced, and the heat treatment energy consumption of the mold is saved. The production cost of rare earth metal is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to a rare earth metal casting mould, especially to a casting mould for preparing rare earth metal and its alloy by molten salt electrolysis method. BACKGROUND

[0002] The molten salt electrolysis method is one of the main methods for preparing rare earth metal and its alloy in industry, which is a metallurgical process of melting the salt of rare earth metal and electrolyzing it as an electrolyte to extract and purify rare earth metal.

[0003] The casting mould is the equipment for producing rare earth metal and its alloy by electrolysis method. The casting mould is used for casting rare earth metal. The rare earth metal casting is a process of pouring rare earth metal melt into a mould, cooling and solidifying, and then obtaining a rare earth metal casting with predetermined shape, size and performance after cleaning treatment.

[0004] In the actual electrolysis process, the rare earth metal is reduced on the cathode and deposited together. The deposited rare earth metal melt needs to be taken out and cast in the mould, and the required rare earth metal product is obtained after cooling and solidification. However, in the process of taking out the rare earth metal melt and casting it in the mould, the electrolyte will be brought into the rare earth metal melt. But because the density of the electrolyte is different from that of the rare earth metal melt, the electrolyte will float on the upper layer of the rare earth metal melt and become slag. Then the slag can be separated from the rare earth metal by cutting. But during the solidification of the rare earth metal melt, which is also the process of the electrolyte floating up to become slag, the casting mould will absorb a large amount of heat from the rare earth metal melt, causing the rare earth metal melt to cool rapidly, while the electrolyte has not completed the full floating, resulting in some slag being mixed in the solidified rare earth metal.

[0005] A rare earth metal casting mould is disclosed in Chinese patent application No. 202022437553.7, which comprises a first surface part and a second surface part. The first surface part and the second surface part enclose a containing area capable of containing rare earth metal. The containing area has an opening above the first surface part and parallel to the first surface part, which is used to inject the rare earth metal into the containing area. The center of the first surface part is provided with a groove, which is located in the containing area. The depth of the groove is greater than or equal to one sixth of the thickness of the first surface part and less than or equal to half of the thickness of the first surface part. The cross-sectional area of the groove is greater than or equal to one tenth of the area of the first surface part and less than or equal to half of the area of the first surface part. The mould facilitates the demoulding of rare earth metal.

[0006] The Chinese patent application No. 201010553758.X discloses a mold for high-purity rare earth metal casting profile, which is provided with a profile casting mold combined in half between the mutually abutting outer titanium plate mold body and the middle titanium plate mold body, and the combined surface of the outer titanium plate mold body and the middle titanium plate mold body is the parting surface of the combined half; a mold upper sleeve is gapingly sleeved into the upper end of the titanium plate casting mold, the side frame of the mold upper sleeve and the mold lower sleeve is provided with a first bolt engaged with the side frame; and a graphite plate is arranged on the lower end surface of the titanium plate casting mold. The mold is convenient to disassemble and demold.

[0007] The Chinese patent application No. 202410908135.1 discloses a casting mold for rare earth metals, which comprises a top mechanism, a casting mold body mechanism and a bottom support mechanism; the casting mold body mechanism comprises a casting mold body, and the casting mold body is provided with a casting cavity; the top mechanism is arranged to be capable of adjusting the distance between the top mechanism and the casting mold body; the top mechanism comprises a top body, and the top body is provided with a liquid outlet connector; the liquid outlet connector is arranged to be matched with the casting cavity; the top body is provided with a first fluid port and a second fluid port; the distance between the bottom support mechanism and the casting mold body is adjustable; the bottom support mechanism comprises a casting cavity end seal; and the casting cavity end seal is arranged to be matched with the casting cavity. The mold is convenient to demold.

[0008] The above molds all focus on whether it is convenient to demold. In the atmospheric environment, the above molds still have a large heat absorption amount for the rare earth metal melt, which causes the rare earth metal melt to cool too quickly, the electrolyte impurities remaining in the rare earth metal melt have not fully floated up, and the rare earth metal melt in the mold has already cooled and solidified, which easily causes residues formed by the rare earth metal product wrapping electrolyte inside, affecting the purity of the rare earth metal product.

[0009] The Chinese patent application No. 202220199313.4 discloses a casting mold for rare earth metal production capable of rapid cooling, which comprises a mold main body and a limiting rod, the limiting rod is arranged outside the mold main body, a casting groove is formed in one side of the mold main body, a liquid cooling groove is formed in the mold main body and corresponds to the casting groove, the liquid cooling groove penetrates through the other side of the mold main body, support frames are fixedly connected to the four corners of the other side of the mold main body, mounting plates are fixedly connected to the upper ends of the support frames away from the mold main body, and circulating pipes are fixedly connected to the mounting plates. The mold utilizes the flowing of the cooling liquid in the liquid cooling groove to rapidly cool the mold main body, so that the rare earth metal melt is rapidly cooled, and the electrolyte is fully floated up.

[0010] In order to slowly cool the rare earth metal melt and make the electrolyte fully float up, in actual production, the casting mold is generally preheated in an oven before casting, which increases the operation steps and energy loss. Practical new type content

[0011] In view of this, the purpose of this utility model is to provide a rare earth metal casting mold that can slow down the cooling and solidification rate of rare earth metal melt, so that electrolyte impurities in rare earth metal melt can float to the surface, which is beneficial for subsequent processes to separate the slag impurities formed by the electrolyte from the rare earth metal.

[0012] The present invention achieves the above objectives by adopting the following technical solution.

[0013] This utility model provides a rare earth metal casting mold, which is a receiving groove structure with an upper opening; it includes a bottom wall and a side wall, the bottom wall and the side wall forming the receiving groove structure, the receiving space of the receiving groove structure is used to receive rare earth metal melt and make the rare earth metal melt form rare earth metal blocks of corresponding shapes.

[0014] The bottom wall has a first cavity inside, and the side wall has a second cavity inside; the first cavity and the second cavity are connected.

[0015] The accommodating space is not connected to either the first cavity or the second cavity.

[0016] According to the rare earth metal casting mold of this utility model, preferably:

[0017] The top of the sidewall is provided with an air hole, which is connected to the second cavity and is open to the outside atmosphere.

[0018] According to the rare earth metal casting mold of this utility model, preferably, it further includes a pore control device, which is disposed on the top of the side wall and is used to adjust the opening size of the pore.

[0019] According to the rare earth metal casting mold of this utility model, preferably, the pore control device is configured as a ball valve structure.

[0020] According to the rare earth metal casting mold of this utility model, preferably, both the first cavity and the second cavity are filled with gaseous refractory.

[0021] According to the rare earth metal casting mold of this utility model, preferably, both the first cavity and the second cavity are filled with solid refractory material.

[0022] According to the rare earth metal casting mold of this utility model, preferably, the air pressure in the first cavity and the second cavity is lower than the external atmospheric pressure.

[0023] According to the rare earth metal casting mold of this utility model, preferably, the second cavity is arranged circumferentially, and its central axis coincides with the central axis of the accommodating space.

[0024] According to the rare earth metal casting mold of this utility model, preferably, the cross-section of the accommodating space is an inverted trapezoid.

[0025] According to the rare earth metal casting mold of this utility model, preferably, the cross-section of the accommodating space is rectangular or square.

[0026] According to the rare earth metal casting mold of this utility model, preferably, the cross-section of the accommodating space is elliptical.

[0027] This invention provides a rare earth metal casting mold that reduces heat loss during the cooling process of molten rare earth metals, slows down the solidification rate, and allows electrolyte impurities in the molten rare earth metal to float to the surface. This facilitates the removal of slag impurities formed by the electrolyte in subsequent processes, promoting the separation of slag impurities from the rare earth metal, thereby reducing losses during rare earth metal separation and improving the purity of the rare earth metal product. Furthermore, it saves energy consumption during mold heat treatment, reducing the production cost of rare earth metals. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of a rare earth metal casting mold according to one embodiment of the present invention.

[0029] Figure 2 for Figure 1 A top-down view.

[0030] Figure 3 for Figure 1 A left-side view diagram.

[0031] Figure 4 This is a schematic diagram of the structure of a rare earth metal casting mold according to another embodiment of the present invention.

[0032] Figure 5 This is a schematic diagram of the structure of a rare earth metal casting mold according to another embodiment of the present invention.

[0033] The annotations in the attached figures are explained as follows:

[0034] 100 - Bottom wall, 110 - First cavity; 200 - Side wall, 210 - Second cavity, 220 - Vent;

[0035] 300-accommodation space;

[0036] 400-Porosity control equipment. Detailed Implementation

[0037] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0038] The rare earth metal casting mold of this utility model includes a bottom wall and side walls. A first cavity is formed inside the bottom wall, and a second cavity is formed inside the side walls. Preferably, vent holes are provided at the top of the side walls. Preferably, the mold also includes a vent control device. A detailed description follows.

[0039] <Bottom wall, side walls, first cavity, and second cavity>

[0040] The rare earth metal casting mold of this invention is a receiving tank structure with an opening at the top. The receiving tank structure is used to hold molten rare earth metal and allow the molten rare earth metal to form rare earth metal blocks of a corresponding shape.

[0041] The rare earth metal casting mold of this utility model includes a bottom wall and side walls, which together form the receiving groove structure. The shape of the receiving space is not particularly limited and can be set according to actual needs. According to one specific embodiment of this utility model, the cross-section of the receiving space is an inverted trapezoid. According to another specific embodiment of this utility model, the cross-section of the receiving space is rectangular. According to yet another specific embodiment of this utility model, the cross-section of the receiving space is square. According to still another specific embodiment of this utility model, the cross-section of the receiving space is elliptical.

[0042] In this invention, a first cavity is formed inside the bottom wall, and a second cavity is formed inside the side wall. The thickness of the first cavity and the thickness of the second cavity can be set according to the thickness of the bottom wall and the side wall. The cross-sectional area of ​​the first cavity and the cross-sectional area of ​​the second cavity can be set according to the cross-sectional area of ​​the bottom wall and the side wall.

[0043] In this invention, the accommodating space is not connected to either the first cavity or the second cavity.

[0044] In a preferred embodiment, the first cavity and the second cavity are connected. This cavity structure within the mold reduces heat absorption by the mold itself from the molten rare earth metal, thereby reducing heat loss during cooling, extending the cooling time of the molten rare earth metal, and allowing the electrolyte to fully float to the surface of the molten rare earth metal to form slag. This improves the purity of the rare earth metal product, reduces losses during subsequent separation of rare earth metal from impurities, saves energy during mold heat treatment, and lowers the production cost of rare earth metals. If the electrolyte cannot fully float, the slag or residue formed by the electrolyte will disperse inside the rare earth metal product, affecting its purity.

[0045] In this invention, the second cavity can be a large cavity or multiple small cavities. The multiple small second cavities are evenly distributed.

[0046] According to one embodiment of this utility model, the second cavity is arranged circumferentially, and its central axis coincides with the central axis of the accommodating space. In this case, the second cavity is a large cavity.

[0047] In this invention, the heat preservation effect can be improved and the cooling rate of the rare earth metal molten liquid can be slowed down by making the air pressure in the first cavity and the second cavity lower than the external atmospheric pressure. In this invention, the mold can be made under negative pressure to ensure that the air pressure in the first cavity and the second cavity is lower than the external atmospheric pressure.

[0048] According to a specific embodiment of the present invention, the first cavity and the second cavity are connected, and the air pressure inside the first cavity and the second cavity is lower than the external atmospheric pressure.

[0049] In this invention, the first and second cavities can also be filled with low thermal conductivity materials. For example, the low thermal conductivity material can be a gaseous refractories or solid refractories. Gaseous refractories refer to materials whose thermal conductivity is less than that of air and which are refractory. Gaseous refractories include, but are not limited to, carbon dioxide. Solid refractories are heat storage materials. Solid refractories include, but are not limited to, porous zirconia fibers and porous alumina fibers. This helps to further reduce the absorption of heat from the rare earth metal molten metal by the mold itself, further improve the heat preservation effect, further slow down the cooling rate of the rare earth metal molten metal, and allow the electrolyte to fully float to the surface, thereby improving the purity of the rare earth metal product.

[0050] In some embodiments, the first cavity and the second cavity are connected, and both the first cavity and the second cavity are filled with gaseous refractory material.

[0051] According to a specific embodiment of the present invention, the first cavity and the second cavity are connected, and both the first cavity and the second cavity are filled with carbon dioxide.

[0052] In other embodiments, the first cavity and the second cavity are connected, and both the first cavity and the second cavity are filled with solid refractory material.

[0053] According to one specific embodiment of the present invention, the first cavity and the second cavity are connected, and both the first cavity and the second cavity are filled with porous alumina fibers. According to another specific embodiment of the present invention, the first cavity and the second cavity are connected, and both the first cavity and the second cavity are filled with porous zirconium oxide fibers.

[0054] The rare earth metal casting mold of this invention can be made of cast steel or cast iron.

[0055] <Stomata>

[0056] The top of the sidewall of this invention is provided with vents, which are connected to the second cavity and open to the outside atmosphere. This invention discovers that by providing such vents, the cooling and solidification rate of the molten rare earth metal can be better slowed down, allowing the electrolyte in the molten rare earth metal to float fully to the surface. This structure also makes the rare earth metal casting mold relatively easier to manufacture.

[0057] When the molten rare earth metal obtained by molten salt electrolysis is poured into the mold, the temperature of the molten rare earth metal is conducted to the interior of the mold. The gas in the first and second cavities expands due to heat and is discharged to the outside atmosphere through the pores at the upper opening edge, reducing the density of the gas inside the first and second cavities. This further reduces the heat conduction rate and slows down the cooling and solidification rate of the molten rare earth metal, allowing the electrolyte in the molten rare earth metal to float fully to the surface, improving the purity of the rare earth metal product, while saving energy consumption for mold heat treatment and reducing the production cost of rare earth metal.

[0058] According to a specific embodiment of the present invention, the first cavity and the second cavity are connected; the top of the side wall is provided with an air hole, the number of which is one or more, the air hole is connected to the second cavity and is open to the outside atmosphere.

[0059] <Porosity Control Equipment>

[0060] The vent control device of this invention is located at the top of the sidewall and is used to adjust the opening size of the vent. This allows control over the gas content within the mold cavity, thereby regulating the cooling rate of the molten rare earth metal.

[0061] In this invention, the structure of the vent control device is not particularly limited. According to one specific embodiment of this invention, the vent control device is configured as a ball valve. By rotating the ball valve handle, the opening size of the vent can be adjusted, thereby adjusting the gas content in the first and second cavities, and further controlling the cooling rate of the rare earth metal molten metal in the casting mold.

[0062] Example 1

[0063] Figure 1 This is a schematic diagram of the structure of a rare earth metal casting mold according to one embodiment of the present invention. Figure 2 for Figure 1 A top-down view. Figure 3 for Figure 1 A left-side view diagram.

[0064] like Figure 1 , Figure 2 and Figure 3As shown, a rare earth metal casting mold in this embodiment is a receiving groove structure with an upper opening. The rare earth metal casting mold includes a bottom wall 100 and a side wall 200, which together form a receiving groove structure. The receiving space 300 of the receiving groove structure is used to receive molten rare earth metal and allow the molten rare earth metal to form rare earth metal blocks of a corresponding shape.

[0065] The bottom wall 100 has a first cavity 110 inside. The thickness of the first cavity 110 is less than the thickness of the bottom wall 100. The side wall 200 has a second cavity 210 inside. The thickness of the second cavity 210 is less than the thickness of the side wall 200. The first cavity 110 and the second cavity 210 are connected.

[0066] The accommodating space 300 is not connected to either the first cavity 110 or the second cavity 210. The first cavity 110 and the second cavity 210 are not connected to the outside atmosphere.

[0067] In this embodiment, the second cavity 210 is arranged circumferentially, and its central axis coincides with the central axis of the accommodating space 300.

[0068] In this embodiment, the cross-section of the accommodating space is an inverted trapezoid, that is, the top area of ​​the accommodating space is larger than the bottom area of ​​the accommodating space.

[0069] Such molds can reduce heat loss from the molten rare earth metals during the cooling process, slow down the solidification rate of the molten rare earth metals, and thus allow electrolyte impurities in the molten rare earth metals to float fully to the surface. This facilitates the removal of slag impurities formed by the electrolyte in subsequent processes, reduces losses during the separation of rare earth metals from slag impurities, and improves the purity of rare earth metal products. In addition, it can save energy consumption in mold heat treatment and reduce the production cost of rare earth metals.

[0070] Example 2

[0071] Figure 4 This is a schematic diagram of the structure of a rare earth metal casting mold according to another embodiment of the present invention.

[0072] like Figure 4 As shown, a rare earth metal casting mold in this embodiment is a receiving groove structure with an upper opening. The rare earth metal casting mold includes a bottom wall 100 and a side wall 200, which together form a receiving groove structure. The receiving space 300 of the receiving groove structure is used to receive molten rare earth metal and allow the molten rare earth metal to form rare earth metal blocks of a corresponding shape.

[0073] The bottom wall 100 has a first cavity 110 inside. The thickness of the first cavity 110 is less than the thickness of the bottom wall 100. The side wall 200 has a second cavity 210 inside. The thickness of the second cavity 210 is less than the thickness of the side wall 200. The first cavity 110 and the second cavity 210 are connected. The accommodating space 300 is not connected to either the first cavity 110 or the second cavity 210.

[0074] In this embodiment, the second cavity 210 is arranged circumferentially, and its central axis coincides with the central axis of the accommodating space 300.

[0075] In this embodiment, the top of the sidewall 200 is also provided with an air hole 220, which is connected to the second cavity 210 and communicates with the outside atmosphere. There can be one or more air holes 220, for example, just one. This allows the first cavity 110 and the second cavity 210 to communicate with the outside atmosphere.

[0076] The mold in this embodiment can further reduce the heat conduction rate and further slow down the cooling and solidification speed of the rare earth metal melt, allowing the electrolyte in the rare earth metal melt to float more fully, improving the purity of the rare earth metal product, while saving mold heat treatment energy consumption and reducing the production cost of rare earth metal.

[0077] Example 3

[0078] Figure 5 This is a schematic diagram of the structure of a rare earth metal casting mold according to another embodiment of the present invention. Figure 5 As shown, a rare earth metal casting mold in this embodiment is a receiving groove structure with an upper opening. The rare earth metal casting mold includes a bottom wall 100, side walls 200, and a pore control device 400. The bottom wall 100 and side walls 200 form a receiving groove structure, the receiving space 300 of which is used to receive molten rare earth metal and allow the molten rare earth metal to form rare earth metal blocks of a corresponding shape.

[0079] The bottom wall 100 has a first cavity 110 inside. The thickness of the first cavity 110 is less than the thickness of the bottom wall 100. The side wall 200 has a second cavity 210 inside. The thickness of the second cavity 210 is less than the thickness of the side wall 200. The first cavity 110 and the second cavity 210 are connected. The accommodating space 300 is not connected to either the first cavity 110 or the second cavity 210.

[0080] In this embodiment, the second cavity 210 is arranged circumferentially, and its central axis coincides with the central axis of the accommodating space 300.

[0081] In this embodiment, the top of the sidewall 200 is also provided with an air hole 220, which is connected to the second cavity 210 and is open to the outside atmosphere. There can be one or more air holes 220, for example, one.

[0082] A vent control device 400 is disposed on the top of the side wall 200 and is used to adjust the opening size of the vent 220. The vent control device 400 can be a ball valve structure. By rotating the handle of the ball valve structure, the opening size of the vent 220 can be adjusted, thereby adjusting the gas content in the first cavity 110 and the second cavity 210, and further controlling the cooling rate of the rare earth metal molten liquid in the casting mold.

[0083] When the hollow part of the ball valve structure is not connected to the vent 220, the vent 220 is completely closed, and the gas content in the first cavity 110 and the second cavity 210 remains constant. When the hollow part of the ball valve structure is connected to the vent 220, the vent 220 is completely open. During the casting of rare earth metal molten liquid, the gas in the cavity expands due to heat and diffuses from the vent 220 into the atmosphere, reducing the gas content in the first cavity 110 and the second cavity 210. This allows control of the cooling rate of the rare earth metal molten liquid by controlling the gas content in the first cavity 110 and the second cavity 210.

[0084] Example 4

[0085] The only difference from Example 1 is that the air pressure in the first cavity 110 and the second cavity 210 is lower than one standard atmosphere (i.e., lower than 0.1 MPa), for example, it can be 0.5 standard atmospheres. This is beneficial for reducing thermal conductivity.

[0086] Example 5

[0087] The only difference from Example 1 is that the first cavity 110 and the second cavity 210 are filled with gaseous refractory material, such as carbon dioxide gas, thereby reducing thermal conductivity and reducing the cooling rate of rare earth metal molten liquid.

[0088] Example 6

[0089] The difference from Example 1 lies only in that the first cavity 110 and the second cavity 210 are filled with a solid refractory material with low thermal conductivity, such as porous zirconia fiber refractory material or porous alumina fiber refractory material. This can further reduce the thermal conductivity and decrease the cooling rate of the rare earth metal molten liquid.

[0090] This utility model is not limited to the above-described embodiments. Any modifications, improvements, or substitutions that can be conceived by those skilled in the art without departing from the essential content of this utility model fall within the scope of this utility model.

Claims

1. A rare earth metal casting mold, characterized in that, It is a receiving tank structure with an upper opening; it includes a bottom wall and a side wall, the bottom wall and the side wall forming the receiving tank structure, the receiving space of the receiving tank structure is used to hold rare earth metal melt and allow the rare earth metal melt to form rare earth metal blocks of corresponding shapes; The bottom wall has a first cavity inside, and the side wall has a second cavity inside; the first cavity and the second cavity are connected. The accommodating space is not connected to either the first cavity or the second cavity.

2. The rare earth metal casting mold according to claim 1, characterized in that: The top of the sidewall is provided with an air hole, which is connected to the second cavity and is open to the outside atmosphere.

3. The rare earth metal casting mold according to claim 2, characterized in that, It also includes an air vent control device, which is disposed on the top of the sidewall, for adjusting the opening size of the air vent.

4. The rare earth metal casting mold according to claim 3, characterized in that, The vent control device is configured as a ball valve.

5. The rare earth metal casting mold according to claim 1, characterized in that, Both the first cavity and the second cavity are filled with gaseous refractory material.

6. The rare earth metal casting mold according to claim 1, characterized in that, Both the first cavity and the second cavity are filled with solid refractory material.

7. The rare earth metal casting mold according to any one of claims 1 to 6, characterized in that, The second cavity is arranged in a circumferential direction, and its central axis coincides with the central axis of the accommodating space.

8. The rare earth metal casting mold according to claim 7, characterized in that, The cross-section of the accommodating space is an inverted trapezoid.

9. The rare earth metal casting mold according to claim 7, characterized in that, The cross-section of the accommodating space is rectangular or square.

10. The rare earth metal casting mold according to claim 7, characterized in that, The cross-section of the accommodating space is elliptical.

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