Crystallization purification apparatus, crystallization purification method, and use thereof

Abstract

The application relates to the technical field of crystallization, and provides a crystallization purification device, a crystallization purification method and purposes thereof. The crystallization purification device comprises a crystallization furnace and a flow resistance mechanism. The crystallization furnace comprises a furnace body, a furnace cover and a crystallization shaft. The flow resistance mechanism comprises a rotating seat, a first driver and a plurality of flow resistance plates. The rotating seat is arranged in the furnace body, and the plurality of flow resistance plates are arranged on the rotating seat. The rotating seat is used for driving the flow resistance plates to rotate around the crystallization shaft. The first driver is connected with the flow resistance plates, and is used for driving the flow resistance plates to move in a direction away from the crystallization shaft. The application sets the flow resistance mechanism in the crystallization furnace. The relative rotation between the flow resistance plates and the crystallization ingot is used to improve the relative linear velocity between the metal melts near the crystallization ingot, promote the diffusion of impurity elements, reduce the disturbance of the melt liquid surface, and effectively improve the purity of the crystallization ingot.

Description

Technical Field

[0001] This application relates to the field of crystallization technology, and in particular to a crystallization purification apparatus, a crystallization purification method, and their applications. Background Technology

[0002] High-purity aluminum crystallization purification is a process that utilizes the segregation characteristics of impurity elements during the transformation of molten aluminum from a liquid to a solid state to produce high-purity aluminum. Segregation refers to the phenomenon where the composition of the solid alloy or pure metal differs from that of the original liquid state during solidification. Generally, the content of trace impurity elements in the solidified crystals is much lower than that in the original molten aluminum. However, during crystallization, the rotation of the crystallization axis causes the molten metal within the furnace to rotate synchronously, resulting in a lower relative linear velocity between the crystallization axis and the molten metal. This weakens the driving force for impurity elements to diffuse from the solid-liquid interface to the liquid phase, increases the thickness of the impurity element enrichment layer, and consequently reduces the impurity element removal rate. Summary of the Invention

[0003] Based on this, one embodiment of this application provides a crystallization purification device, a crystallization purification method, and their applications with good crystallization purification effect.

[0004] In a first aspect, this application provides a crystallization purification apparatus, the crystallization purification apparatus comprising:

[0005] A crystallization furnace includes a furnace body, a furnace cover, and a crystallization shaft. The furnace body is used to melt metal and contain the molten metal. The furnace cover is used to cover the furnace body. The crystallization shaft passes through the furnace cover and is disposed in the furnace body. The crystallization shaft is used for crystallization purification to form crystallized ingots.

[0006] The flow-blocking mechanism includes a rotating base, a first driver, and multiple flow-blocking plates. The rotating base is disposed inside the furnace body, and the multiple flow-blocking plates are respectively disposed on the rotating base. The rotating base is used to drive the flow-blocking plates to rotate around the crystallization axis. The first driver is connected to the flow-blocking plates and is used to drive the flow-blocking plates to move in a direction away from the crystallization axis.

[0007] In some embodiments, the flow-blocking plates are arranged at equal intervals along the circumference of the crystallization axis.

[0008] In some embodiments, the number of flow barriers is 4 to 16.

[0009] In some embodiments, the width of the baffle plate is 0.1 to 0.2 times the inner diameter of the furnace body.

[0010] In some embodiments, the first driver includes a plurality of slide rails disposed on the rotating base, the plurality of slide rails being arranged circumferentially at intervals along the crystallization axis, and the slide rails all extending in a direction away from the crystallization axis; the flow baffles are respectively slidably disposed on the slide rails.

[0011] Optionally, the slide rail includes a first slide rail and a second slide rail, wherein the distance between the first slide rail and the crystallization axis is less than the distance between the second slide rail and the crystallization axis.

[0012] In some embodiments, the flow-blocking mechanism further includes a second driver disposed on the flow-blocking plate, the second driver being used to drive the flow-blocking plate to rotate about its length.

[0013] In some embodiments, the flow baffle is slidably disposed on the slide rail by the second driver, and the first driver is used to drive the second driver to slide on the slide rail so as to move the flow baffle away from the crystallization axis.

[0014] Secondly, this application provides a crystallization purification method, wherein the crystallization purification method employs the crystallization purification apparatus as described in the first aspect, comprising:

[0015] Metal is added to the furnace and heated to melt it into a molten metal, which is then kept at a constant temperature.

[0016] The crystallization shaft is inserted into the molten metal, the crystallization shaft rotates and a cooling medium is introduced for crystallization purification, and a crystallization ingot is formed on the surface of the crystallization shaft;

[0017] The flow-blocking mechanism is inserted into the molten metal. The rotating seat drives the flow-blocking plate to rotate around the crystallization axis. As the crystallization ingot gradually increases in size, the first driver adjusts the distance between the flow-blocking plate and the crystallization ingot to maintain the distance between the flow-blocking plate and the crystallization ingot at 20mm~100mm.

[0018] After the crystallization purification is completed, the crystallization shaft is removed to obtain a crystallization ingot.

[0019] In some embodiments, the rotating seat causes the flow-blocking plate to rotate about the crystallization axis in a direction opposite to the rotation direction of the crystallization axis.

[0020] Optionally, the rotational speed of the baffle plate around the crystallization axis is 0.5 to 2 times the rotational speed of the crystallization axis.

[0021] Optionally, the rotation speed of the crystallization axis is 90 rpm to 270 rpm.

[0022] In some embodiments, the first driver drives the baffle plate away from the crystallization ingot at the same speed as the crystallization speed of the crystallization ingot.

[0023] Optionally, the crystallization rate is 50 mm / h to 200 mm / h.

[0024] In some embodiments, the first driver includes a plurality of slide rails disposed on the rotating base, the baffle plate moves along the slide rails, and the baffle mechanism further includes a second driver for driving the baffle plate to rotate about the axial direction of the baffle plate.

[0025] Optionally, when the baffle plate is inserted into the molten metal and moves along the slide rail, the angle between the baffle plate and the slide rail is less than or equal to 15°.

[0026] Optionally, when the crystallization purification is completed, the second driver drives the baffle plate to rotate. The rotation direction of the baffle plate is the same as the rotation direction of the crystallization shaft, and the angle between the baffle plate and the slide rail is 75°~90°.

[0027] In some embodiments, after the crystallization purification is completed, the rotation of the crystallization axis and the rotation of the baffle plate around the crystallization axis are stopped, and the second driver drives the baffle plate to rotate so that the baffle plate is perpendicular to the slide rail.

[0028] Optionally, the rotation direction of the flow-blocking plate is the same as the rotation direction of the crystallization axis.

[0029] Thirdly, this application provides a use of the crystallization purification apparatus as described in the first aspect, the crystallization purification apparatus being used for the crystallization purification of aluminum.

[0030] Compared with traditional technologies, this application has at least the following beneficial effects:

[0031] This application incorporates a flow-restricting mechanism within the crystallization furnace. The relative rotation between the flow-restricting plate and the crystallization ingot increases the relative linear velocity between the molten metal near the ingot. As the ingot grows, a first actuator moves the flow-restricting plate away from the ingot, achieving localized flow restriction—acting only on the liquid phase region at the solid-liquid interface. This better maintains a stable liquid surface and prevents oxidation of the molten metal and the ingot. The flow-restricting mechanism's position is adjustable, maximizing the diffusion of impurity elements and minimizing molten surface disturbance during crystallization purification, effectively improving the purity of the crystallization ingot. Attached Figure Description

[0032] Figure 1 This is a diagram showing the initial state of a crystallization apparatus provided in one embodiment of this application during crystallization purification.

[0033] Figure 2 This is a state diagram of a crystallization apparatus provided in one embodiment of this application when crystallization purification is completed;

[0034] Figure 3 This is a diagram showing the arrangement of slide rails on a rotary seat according to one embodiment of this application;

[0035] Figure 4 This is a diagram showing the rotational state of a baffle plate under the action of a second driver, according to one embodiment of this application.

[0036] Among them, 100-crystallization furnace; 110-furnace body; 120-furnace cover; 130-crystallization shaft; 200-flow-blocking mechanism; 210-rotating seat; 220-first driver; 221-first slide rail; 222-second slide rail; 230-flow-blocking plate; 240-second driver. Detailed Implementation

[0037] The present application will be further described in detail below with reference to the embodiments and examples. These embodiments and examples are only for illustrating the present application and are not intended to limit the scope of the present application. The purpose of providing these embodiments and examples is to make the disclosure of the present application more thorough and comprehensive. It should also be understood that the present application can be implemented in many different forms and is not limited to the embodiments and examples described herein. Those skilled in the art can make various modifications or alterations without departing from the spirit of the present application, and the equivalent forms obtained also fall within the protection scope of the present application. In addition, numerous specific details are set forth in the following description to provide a fuller understanding of the present application. It should be understood that the present application can be implemented without one or more of these details.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0039] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified, and there are no contradictions or mutual constraints, each "optional" entry shall be independent.

[0040] In this application, the terms "first aspect," "second aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first aspect," "second aspect," etc., serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on quantity.

[0041] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0042] In this application, when numerical intervals (i.e., numerical ranges) are mentioned, unless otherwise specified, the distribution of selectable numerical values ​​within the numerical interval is considered continuous, and includes the two endpoints of the numerical interval (i.e., the minimum and maximum values), as well as every numerical value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that numerical interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints, which is equivalent to directly listing every integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical ranges disclosed in this application should be understood to include any and all subranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, percentage, ratio, etc. The term "numerical interval" can be broadly included to include percentage intervals, ratio intervals, proportion intervals, etc.

[0043] All references to this application are incorporated herein by reference as if each document were individually incorporated herein by reference. Unless they conflict with the purpose and / or technical solution of this application, all cited references are incorporated herein by reference in their entirety and for all purposes. When references are cited in this application, the definitions of relevant technical features, terms, nouns, phrases, etc., are also incorporated herein by reference. Examples and preferred embodiments of the cited technical features may also be incorporated herein by reference, but only to the extent that they enable the implementation of this application. It should be understood that when the cited content conflicts with the description in this application, this application shall prevail or modifications shall be made adaptably to the description in this application.

[0044] In traditional crystallization techniques, during the crystallization purification process, the molten metal rotates synchronously with the crystallization axis, reducing the relative linear velocity between the crystallization ingot surface and the molten metal. This weakens the driving force for impurity elements to diffuse from the solid-liquid interface to the liquid phase, increasing the thickness of the impurity enrichment layer and thus reducing the impurity removal rate. Furthermore, while electromagnetic stirring is used in traditional techniques to increase the relative linear velocity between the molten metal and the crystallization ingot, the stirring of the entire molten metal during electromagnetic stirring easily causes surface fluctuations, leading to oxidation and affecting the purification yield. Moreover, electromagnetic stirring is insufficient to further increase the relative linear velocity between the molten metal and the crystallization ingot, resulting in poor crystallization purification.

[0045] The first aspect of this application provides a crystallization purification apparatus, such as... Figure 1 and Figure 2 As shown, the crystallization purification apparatus includes a crystallization furnace 100 and a flow-blocking mechanism 200.

[0046] The crystallization furnace 100 includes a furnace body 110, a furnace cover 120, and a crystallization shaft 130. The furnace body 110 is used to melt metal and contain molten metal. The furnace cover 120 is used to cover the furnace body 110. The crystallization shaft 130 passes through the furnace cover 120 and is located inside the furnace body 110. The crystallization shaft 130 is used for crystallization purification to form crystallization ingots.

[0047] The flow-blocking mechanism 200 includes a rotating seat 210, a first driver 220, and multiple flow-blocking plates 230. The rotating seat 210 is disposed inside the furnace body 110, and the multiple flow-blocking plates 230 are respectively disposed on the rotating seat 210. The rotating seat 210 is used to drive the flow-blocking plates 230 to rotate around the crystallization axis 130. The first driver 220 is connected to the flow-blocking plates 230 and is used to drive the flow-blocking plates 230 to move in a direction away from the crystallization axis 130.

[0048] like Figure 1 As shown, in the initial stage of crystallization purification, the flow-blocking plate 230 maintains a distance from the crystallization axis 130. For example... Figure 2 As shown, when crystallization purification is complete, the flow baffle 230 maintains a distance from the crystallization ingot.

[0049] This application incorporates a flow-restricting mechanism 200 within the crystallization furnace 100. The relative rotation between the flow-restricting plate 230 and the crystallization ingot increases the relative linear velocity between the molten metal near the ingot. As the crystallization ingot grows, the first driver 220 moves the flow-restricting plate 230 away from the ingot, achieving localized flow restriction—acting only on the liquid phase region at the solid-liquid interface. This better maintains a stable liquid surface and prevents oxidation of the molten metal and the crystallization ingot. The flow-restricting mechanism 200 features an adjustable position of the flow-restricting plate 230, maximizing the diffusion of impurity elements and reducing molten surface disturbance during crystallization purification, effectively improving the purity of the crystallization ingot.

[0050] It is understood that the crystallization furnace 100 in this application also includes a driver for driving the crystallization shaft 130 to rotate. The driver can be connected to the crystallization shaft 130 gear by a rotary motor to synchronously drive the crystallization shaft 130 to rotate. The speed is adjustable and supports continuous variable speed operation.

[0051] Understandably, the crystallization shaft 130 has cooling channels, into which cooling medium can be introduced to ensure the formation of crystallization ingots on the crystallization shaft 130. Optionally, the cooling channels can be finned copper tubes with high thermal conductivity. Cooling medium can be introduced into the cooling channels via a cooling pump, which can output cooling fluid media with different flow rates and pressures.

[0052] In some embodiments, the flow-blocking plates 230 are arranged at equal intervals along the circumference of the crystallization axis 130.

[0053] In some embodiments, the number of flow baffles 230 is 4 to 16, for example, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16. The selection of the number and arrangement of the flow baffles 230 as described above in this application can effectively impede the flow of molten aluminum while reducing disturbance to the molten surface, thereby avoiding problems such as the enrichment of impurity elements and oxide slagging near the solid-liquid interface.

[0054] In some embodiments, the width of the baffle plate 230 is 0.1 to 0.2 times the inner diameter of the furnace body 110, for example, it can be 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, or 0.20 times. The width of the baffle plate 230 selected above in this application achieves maximum flow obstruction while increasing the relative linear velocity of the solid and liquid phases, thus balancing purification effect and yield.

[0055] In some embodiments, such as Figure 3As shown, the first driver 220 includes multiple slide rails disposed on the rotating base 210. The slide rails are arranged at intervals along the circumference of the crystallization axis 130, and all slide rails extend in a direction away from the crystallization axis 130. Baffle plates 230 are slidably disposed on the slide rails. Optionally, each slide rail is provided with a slider, and the baffle plate 230 is disposed on the slider, so that the baffle plate 230 is driven to slide on the slide rail by the slider.

[0056] This application sets the flow baffle 230 on the slide rail for sliding, which can ensure the stability of the flow baffle 230 during rotation, and make the direction of movement of the flow baffle 230 away from the crystallization ingot, so that during the growth of the crystallization ingot, the flow of the molten metal near the crystallization ingot is always blocked, ensuring stable crystallization purification.

[0057] Alternatively, for example Figure 3 As shown, the slide rails include a first slide rail 221 and a second slide rail 222. The distance between the first slide rail 221 and the crystallization axis 130 is smaller than the distance between the second slide rail 222 and the crystallization axis 130. This application, by setting two types of slide rails, eliminates the need for numerous flow-blocking plates 230 around the crystallization ingot when the ingot diameter is small. Furthermore, excessive flow-blocking plates 230 may result in a smaller volume of the metal solution around the ingot, affecting the initial crystallization effect. When the crystallization ingot grows to a certain size, such as reaching the second slide rail 222, due to the larger volume of the ingot, using only the flow-blocking plates 230 on the first slide rail 221 for flow blocking may result in a relatively low linear velocity at the solid-liquid interface. Therefore, the flow-blocking plates 230 on the second slide rail 222 are introduced to improve the flow blocking effect.

[0058] Understandably, the first driver 220 has the driving capability to move the baffle 230 along the slide rail. For example, it may also include a telescopic cylinder or a stepper motor to adjust the movement speed of the baffle 230 on the slide rail. Furthermore, to ensure that the movement speed of each baffle 230 is consistent, a controller can be set to make the movement speed of each telescopic cylinder the same.

[0059] In some embodiments, such as Figure 4 As shown, the flow-blocking mechanism 200 also includes a second driver 240, which is disposed on the flow-blocking plate 230 and is used to drive the flow-blocking plate 230 to rotate about its length. Optionally, when the flow-blocking plate 230 slides on the slide rail via the slider, the second driver 240 can be disposed on the flow-blocking plate 230 and connected to the slider, thereby driving the flow-blocking plate 230 to rotate.

[0060] It is understandable that the length direction of the flow baffle 230 is parallel to the axial direction of the crystallization axis 130. For example, if the axial direction of the crystallization axis 130 is perpendicular to the horizontal plane, then the length direction of the flow baffle 230 is a vertical direction perpendicular to the horizontal plane.

[0061] This application sets up a second driver 240 to drive the flow baffle 230 to rotate, thereby adjusting the angle of the flow baffle 230 according to different crystallization purification stages, realizing different flow obstruction states of the flow baffle 230 on the crystallization ingot, and ensuring the optimal crystallization purification effect at each stage.

[0062] It should be noted that, in this application, the rotation of the baffle 230 refers to its rotation around any position of the baffle 230. Furthermore, revolution refers to the rotation of the baffle 230 around other objects.

[0063] In some embodiments, the axis of rotation of the baffle plate 230 under the action of the second driver 240 can be any direction along the length of the baffle plate 230. For example, it can rotate about the axis along the length of the baffle plate 230, or it can rotate about one of the long sides of the baffle plate 230 as the axis.

[0064] In some embodiments, the flow baffle 230 is slidably disposed on the slide rail by the second driver 240, and the first driver 220 is used to drive the second driver 240 to slide on the slide rail so as to drive the flow baffle 230 to move in a direction away from the crystallization axis 130.

[0065] In some embodiments, the rotating base 210 is connected to a driver via a transmission assembly, so that the driver drives the rotating base 210 to rotate. Optionally, the transmission assembly includes a transmission gear and a transmission bushing; the transmission gear is connected to the rotating base 210 via the transmission bushing, and the driver drives the rotating base 210 to rotate by driving the transmission gear.

[0066] In some embodiments, the material of the crystallization shaft 130 may be any one of high-purity graphite, silicon nitride, silicon carbide, and corundum.

[0067] In some embodiments, the baffle 230 may be a rectangular sheet structure. Optionally, the baffle 230 may be made of a high-temperature resistant material, such as silicon nitride or corundum.

[0068] In some embodiments, the length of the baffle plate 230 may be the same as the length of the crystallization shaft 130 immersed in the molten metal.

[0069] In some embodiments, the rotating seat 210 is disposed on the furnace cover 120, which enables the baffle plate 230 to be inserted into the molten metal when the furnace cover 120 is being installed.

[0070] A second aspect of this application provides a crystallization purification method, which employs the crystallization purification apparatus as described in the first aspect, comprising:

[0071] The metal is added into the furnace body 110 and heated to melt it into a molten metal, which is then kept at a constant temperature.

[0072] The crystallization shaft 130 is inserted into the molten metal. The crystallization shaft 130 rotates and a cooling medium is introduced for crystallization purification, forming a crystallization ingot on the surface of the crystallization shaft 130.

[0073] Insert the flow-blocking mechanism 200 into the molten metal. The rotating seat 210 drives the flow-blocking plate 230 to rotate around the crystallization axis 130. As the crystallization ingot gradually increases in size, the first driver 220 adjusts the distance between the flow-blocking plate 230 and the crystallization ingot to keep the distance between the flow-blocking plate 230 and the crystallization ingot at 20mm~100mm.

[0074] After the crystallization purification is completed, the crystallization shaft 130 is removed to obtain the crystallization ingot.

[0075] In the crystallization purification process, the flow baffle 230 rotates relative to the crystallization shaft 130, and the relative distance between the flow baffle 230 and the crystallization ingot is controlled, thereby achieving local flow obstruction of the molten metal near the crystallization ingot, effectively increasing the relative linear velocity at the solid-liquid contact point, improving the crystallization purification effect, and avoiding fluctuations in the molten metal surface, thus reducing the risk of oxidation.

[0076] This application controls the distance between the flow baffle 230 and the crystallization ingot as described above, which can significantly improve the crystallization purification effect. If the distance is relatively close, the crystallization ingot may come into contact with the flow baffle 230, causing damage to the crystallization ingot, and there is also the problem of the flow baffle and the crystallization ingot getting stuck, resulting in purification interruption. If the distance is relatively far, it may result in a low relative linear velocity at the solid-liquid interface, poor crystallization purification effect, and may also affect the yield of the crystallization ingot.

[0077] It should be noted that in this application, there is a relative velocity at the contact surface between the crystallized ingot and the molten metal. This can be achieved by the flow baffle 230 rotating around the crystallization axis 130 at a different speed than the crystallization axis 130 itself, creating a velocity difference between the molten metal and the crystallization axis 130, thus enabling relative rotation between the crystallized ingot and the molten metal. Alternatively, the rotation direction of the flow baffle 230 around the crystallization axis 130 can be different from the rotation direction of the crystallization axis 130. In some embodiments, the rotating seat 210 drives the flow baffle 230 to rotate around the crystallization axis 130 in a direction opposite to the rotation direction of the crystallization axis 130. This application utilizes the fact that the rotation direction of the crystallization axis 130 is opposite to the revolution direction of the flow baffle 230 to effectively increase the relative linear velocity at the solid-liquid interface between the molten metal and the crystallized ingot, effectively promoting the effective diffusion of impurity elements, reducing the thickness of the impurity element enrichment layer, and further improving the purity of the crystallized ingot.

[0078] Optionally, the rotational speed of the baffle plate 230 around the crystallization axis 130 is 0.5 to 2 times the rotational speed of the crystallization axis 130, for example, it can be 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2.0 times. The selection of the rotational speed of the crystallization axis 130 and the rotational speed of the baffle plate 230 around the crystallization axis 130 in this application can promote the diffusion driving force and speed of impurity elements from the solid phase to the liquid phase. If the rotational speed of the baffle plate 230 is relatively fast, it may cause disturbance around the molten surface, exacerbating oxidation and slagging on the aluminum melt surface.

[0079] Optionally, the rotation speed of the crystallization axis 130 is 90 rpm to 270 rpm, for example, it can be 90 rpm, 110 rpm, 130 rpm, 150 rpm, 170 rpm, 190 rpm, 210 rpm, 230 rpm, 250 rpm or 270 rpm.

[0080] In some embodiments, the first driver 220 drives the baffle plate 230 away from the crystallization ingot at the same speed as the crystallization speed of the crystallization ingot. This application controls the speed at which the baffle plate 230 moves away from the crystallization ingot based on the crystallization speed of the crystallization ingot, thereby effectively ensuring the relative distance between the baffle plate 230 and the crystallization ingot, and avoiding the distance between the baffle plate 230 and the crystallization ingot being too far or too close, which would affect the purification effect.

[0081] Optionally, the crystallization rate can be 50 mm / h to 200 mm / h, for example, 50 mm / h, 60 mm / h, 80 mm / h, 100 mm / h, 120 mm / h, 140 mm / h, 160 mm / h, 180 mm / h, or 200 mm / h. It is understood that the crystallization rate can be reasonably selected based on the material of the molten metal and the parameters of the cooling medium in the crystallization shaft 130.

[0082] In some embodiments, the first driver 220 includes a plurality of slide rails disposed on the rotating seat 210, the baffle plate 230 moves along the slide rails, and the baffle mechanism 200 further includes a second driver 240, which is used to drive the baffle plate 230 to rotate about the axial direction of the baffle plate 230.

[0083] Optionally, when the baffle plate 230 is inserted into the molten metal and moves along the slide rail, the angle between the baffle plate 230 and the slide rail is less than or equal to 15°, for example, it can be 0°, 2°, 4°, 6°, 8°, 10°, 12°, 14°, or 15°. It can be selected as 0°. It is understood that in this application, the angle between the baffle plate 230 and the slide rail refers to the angle between the width direction of the baffle plate 230 and the extension direction of the slide rail.

[0084] The angle of the flow baffle 230 during its movement is selected as described above. The width direction of the flow baffle 230 is basically perpendicular to the tangent direction of the crystallization axis 130, which can maximize the obstruction of the flow rate of the molten metal, ensure the flow baffle effect of the flow baffle 230, effectively improve the relative linear velocity of the solid-liquid interface, and promote the effective diffusion of impurity elements.

[0085] Optionally, when crystallization purification is complete, the second driver 240 drives the baffle plate 230 to rotate. The rotation direction of the baffle plate 230 is the same as the rotation direction of the crystallization shaft 130, and the angle between the baffle plate 230 and the slide rail is 75°~90°, for example, 75°, 77°, 79°, 81°, 83°, 85°, 87°, 89°, or 90°. It is understood that the angle between the baffle plate 230 and the slide rail in this application refers to the angle between the width direction of the baffle plate 230 and the extension direction of the slide rail. It is understood that when crystallization purification is complete, it means that the volume of the crystallized ingot reaches the crystallization requirement. Furthermore, when the baffle plate 230 moves to the end of the slide rail away from the crystallization shaft 130, it represents the maximum volume of crystallized ingot that the furnace body 110 can produce. Therefore, when the baffle plate 230 moves to the end of the slide rail away from the crystallization shaft 130, crystallization purification is complete.

[0086] When crystallization purification is completed, adjust the angle between the baffle plate 230 and the slide rail as above. This will guide the surface slag in the molten metal during the crystallization process (which refers to the oxidation of the molten aluminum due to disturbance, resulting in aluminum oxide floating on the surface of the molten metal, commonly known as slag formation) to the furnace wall 110, preventing it from contacting the crystallized ingot and ensuring the purity of the crystallized ingot.

[0087] In some embodiments, after crystallization purification is completed, the rotation of the crystallization shaft 130 and the rotation of the baffle plate 230 around the crystallization shaft 130 are stopped. The second driver 240 drives the baffle plate 230 to rotate, making the baffle plate 230 perpendicular to the slide rail. Optionally, the rotation direction of the baffle plate 230 is the same as the rotation direction of the crystallization shaft 130.

[0088] After crystallization, the baffle plate 230 is adjusted as above to prevent oxides located between the crucible wall and the baffle plate from adhering to the surface of the crystallized ingot when it is removed from the molten metal.

[0089] like Figure 4 As shown, it illustrates the state of the flow baffle 230 before and after crystallization purification. Specifically, during crystallization purification... Figure 4 The angle between the baffle plate 230 and the slide rail is 0°. Upon completion of crystallization purification, the baffle plate 230 rotates 45° to guide the oxides in the molten metal to the wall of the furnace body 110. After crystallization purification is complete, the baffle plate 230 rotates another 45°, making the angle between the baffle plate 230 and the slide rail 90°, and the crystal ingot is removed.

[0090] In some embodiments, when the baffle plate 230 is inserted into the molten metal, it can first be placed above the surface of the molten metal and allowed to stand. Optionally, the distance between the baffle plate 230 and the surface of the molten metal is greater than or equal to 50 mm, the standing time is 1 min to 5 min, and the insertion speed of the baffle plate 230 is less than or equal to 10 mm / s. This application preheats the baffle plate 230 by placing it above the surface of the molten metal for a period of time, thus avoiding direct insertion of the baffle plate 230 into the molten aluminum and affecting its service life.

[0091] In some embodiments, the temperature difference between the holding temperature and the liquidus temperature of the molten metal is 30°C to 60°C, for example, it can be 30°C, 33°C, 36°C, 39°C, 42°C, 45°C, 48°C, 51°C, 54°C, 57°C, or 60°C. It is understood that the liquidus temperature refers to the highest temperature at which a material begins to change from a liquid to a solid state.

[0092] Exemplarily, a method for purifying aluminum by crystallization using the above-described crystallization purification apparatus is provided, comprising the following steps:

[0093] S1. Add the metal ingot into the furnace body 110, heat and melt it, and keep it at the crystallization process temperature.

[0094] S2. Suspend the baffle plate 230 above the molten metal, keeping the lower end of the baffle plate 230 at least 50 mm above the surface of the molten metal. After standing for 1 to 5 minutes, slowly insert the baffle plate 230 into the molten metal at a speed not exceeding 10 mm / s.

[0095] S3. Insert the preheated crystallization shaft 130 into the molten metal, and pass the cooling medium into the cooling channel inside the crystallization shaft 130 for cooling, so as to form a crystallization ingot on the surface of the crystallization shaft 130. The crystallization speed is 50mm / h~200mm / h.

[0096] S4. Start the crystallization shaft 130 to rotate at a speed of 90 rpm to 270 rpm.

[0097] S5. Start the flow-blocking mechanism 200. The flow-blocking plate 230 moves along the slide rail, always maintaining a distance of 20mm~100mm between the flow-blocking plate 230 and the surface of the crystallization ingot. The rotation speed of the flow-blocking plate 230 around the crystallization axis 130 is 0.5 times~2 times the rotation speed of the crystallization axis 130, and the rotation direction is opposite to the rotation direction of the crystallization axis 130. At the same time, as the crystallization ingot grows, the flow-blocking plate 230 moves along the slide rail in a direction away from the crystallization ingot, maintaining a distance between the flow-blocking plate 230 and the surface of the crystallization ingot.

[0098] S6. When crystallization purification is completed, the second driver 240 drives the baffle plate 230 to rotate. The rotation direction is consistent with the rotation direction of the crystallization shaft 130, and the rotation angle is 75°~90°. Through the centrifugal force of the rotation of the crystallization shaft 130, the oxide on the surface of the molten metal is guided to the wall of the furnace body 110 through the baffle plate 230.

[0099] S7: Crystallization purification ends. Stop the rotation of crystallization shaft 130 and the revolution of baffle plate 230. The second driver 240 drives baffle plate 230 to rotate again. The rotation direction is consistent with the rotation direction of crystallization shaft 130, so that baffle plate 230 is perpendicular to slide rail. Then, slowly pull the crystallization ingot out of the molten metal, turn off the cooling system, and complete the crystallization purification.

[0100] Repeating steps S1-S7 allows for continuous purification.

[0101] The third aspect of this application provides the use of the crystallization purification apparatus as described in the first aspect, the crystallization purification apparatus being used for the crystallization purification of aluminum.

[0102] The embodiments of this application will be described in detail below with reference to examples. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of this application. For experimental methods in the following embodiments where specific conditions are not specified, please refer to the guidelines given in this application, or follow experimental manuals or conventional conditions in the art, or follow the conditions recommended by the manufacturer, or refer to experimental methods known in the art.

[0103] Example 1

[0104] This embodiment provides a crystallization purification apparatus, including a crystallization furnace 100 and a flow-blocking mechanism 200.

[0105] The crystallization furnace 100 includes a furnace body 110, a furnace cover 120, and a crystallization shaft 130. The inner diameter of the furnace body 110 is 720 mm. The flow-blocking mechanism 200 includes a rotating seat 210, a first driver 220, a second driver 240, and four flow-blocking plates 230. The width of each flow-blocking plate 230 is 108 mm. The rotating seat 210 is mounted on the furnace cover 120. The first driver 220 includes four slide rails arranged at equal intervals along the circumference of the crystallization shaft 130. The flow-blocking plates 230 are correspondingly mounted on the slide rails and are slidably mounted on the slide rails via the second driver 240. The first driver 220 drives the second driver 240 to slide along the slide rails and moves the flow-blocking plates 230 along the slide rails. The second driver 240 drives the flow-blocking plates 230 to rotate.

[0106] This embodiment also provides a crystallization purification method, including the following steps:

[0107] S1. Add aluminum ingots with a purity of 5N (99.999%) into furnace body 110, heat and melt them, and hold at 710℃ for 30 minutes.

[0108] S2. Suspend the baffle plate 230 above the molten metal, keeping the lower end of the baffle plate 230 50 mm above the molten metal surface. After standing for 3 minutes, slowly insert the baffle plate 230 into the molten metal at a speed of 5 mm / s. The angle between the baffle plate 230 and the slide rail is 0°.

[0109] S3. Insert the preheated crystallization shaft 130 into the molten aluminum and pass the cooling medium into the cooling channel inside the crystallization shaft 130 for cooling, so as to form a crystallization ingot on the surface of the crystallization shaft 130. The crystallization speed is 150 mm / h.

[0110] S4. Start the crystallization shaft to rotate 130° at a speed of 120 rpm.

[0111] S5. Start the flow-blocking mechanism 200. The flow-blocking plate 230 moves along the slide rail, always maintaining a distance of 60mm between the flow-blocking plate 230 and the surface of the crystallization ingot. The flow-blocking plate 230 rotates around the crystallization axis 130 at a speed of 120rpm, and the rotation direction is opposite to the rotation direction of the crystallization axis 130. At the same time, as the crystallization ingot grows, the flow-blocking plate 230 moves along the slide rail in a direction away from the crystallization ingot according to the crystallization speed, maintaining the distance between the flow-blocking plate 230 and the surface of the crystallization ingot.

[0112] S6. After crystallization purification for 60 minutes, the second driver 240 drives the baffle plate 230 to rotate. The rotation direction is the same as the rotation direction of the crystallization shaft 130, and the rotation angle is 45°. Through the centrifugal force of the rotation of the crystallization shaft 130, the oxide on the surface of the molten metal is guided to the wall of the furnace body 110 through the baffle plate 230.

[0113] S7: After 90 minutes of crystallization purification, stop the rotation of the crystallization shaft 130 and the revolution of the baffle plate 230. The second driver 240 drives the baffle plate 230 to rotate again, with the rotation direction consistent with the rotation direction of the crystallization shaft 130, so that the baffle plate 230 is perpendicular to the slide rail. Then, slowly pull the crystallization ingot out of the molten metal, turn off the cooling system, and complete the crystallization purification.

[0114] Example 2

[0115] Aluminum was purified by crystallization using the crystallization purification apparatus of Example 1, except that the distance between the flow baffle 230 and the crystallization ingot was 30 mm.

[0116] Example 3

[0117] Aluminum was purified by crystallization using the crystallization purification apparatus of Example 1, except that the distance between the flow baffle 230 and the crystallization ingot was 100 mm.

[0118] Example 4

[0119] Aluminum was purified by crystallization using the crystallization purification apparatus of Example 1, except that the revolution speed of the baffle plate 230 was 60 rpm.

[0120] Example 5

[0121] Aluminum was purified by crystallization using the crystallization purification apparatus of Example 1, except that the revolution speed of the baffle plate 230 was 240 rpm.

[0122] Example 6

[0123] The crystallization purification apparatus of Example 1 is used to purify aluminum by crystallization. The difference is that during the crystallization purification process, the angle between the flow baffle 230 and the slide rail is 15° when the molten metal is inserted, and the angle between the flow baffle 230 and the slide rail is 75° when the crystallization is completed.

[0124] Example 7

[0125] Aluminum was purified by crystallization using the crystallization purification apparatus of Example 1, except that the number of slide rails was 8, the number of flow baffles 230 was 8, and the revolution speed of the flow baffles 230 was 60 rpm.

[0126] Example 8

[0127] Aluminum is purified by crystallization using the crystallization purification device of Example 1. The difference is that there are 8 slide rails and 8 flow baffles 230, and the revolution speed of the flow baffles 230 is 60 rpm. The distance between the flow baffles 230 and the crystallization ingot is maintained at 30 mm.

[0128] Example 9

[0129] Aluminum is purified by crystallization using the crystallization purification device of Example 1. The difference is that there are 8 slide rails and 8 flow baffles 230, and the revolution speed of the flow baffles 230 is 0 rpm. The distance between the flow baffles 230 and the crystallization ingot is maintained at 30 mm.

[0130] Example 10

[0131] The crystallization purification apparatus of Example 1 is used to purify aluminum by crystallization. The difference is that the slide rail includes four first slide rails 221 and four second slide rails 222, wherein the distance between the first slide rail 221 and the crystallization axis 130 is 90mm, and the distance between the second slide rail 222 and the crystallization axis 130 is 60mm.

[0132] Comparative Example 1

[0133] Aluminum was purified by crystallization using the crystallization purification apparatus of Example 1, except that it did not have a flow baffle 230.

[0134] Comparative Example 2

[0135] Aluminum was purified by crystallization using the crystallization purification apparatus of Example 1, except that the flow obstruction mechanism 200 was replaced with an electromagnetic stirrer. The operating parameters of the electromagnetic stirrer were an electromagnetic frequency of 45Hz and a current intensity of 950A.

[0136] Comparative Example 3

[0137] Aluminum was purified by crystallization using the crystallization purification apparatus of Example 1, except that the distance between the flow baffle 230 and the crystallization ingot was kept at 250 mm.

[0138] Comparative Example 4

[0139] Aluminum was purified by crystallization using the crystallization purification apparatus of Example 1, except that the distance between the flow baffle 230 and the crystallization ingot was kept at 10 mm.

[0140] The purity and yield of the crystallized ingots prepared in the above examples and comparative examples were statistically analyzed. The composition was tested using a glow discharge mass spectrometer (GDMS). The statistical results are shown in Table 1.

[0141] Table 1

[0142]

[0143] Note:

[0144] Yield, i.e., actual yield of crystallized ingots = weight of crystallized ingots / weight of melt in crucible.

[0145] Purification rate reflects the crystallization purification ability. Purification rate = (melt impurity content - crystallization ingot impurity content) / melt impurity content. The higher the purification rate, the stronger the purification ability and the better the purification effect.

[0146] Purity deviation represents the uniformity and consistency of purity of the crystallized ingot. In this embodiment, it refers to the purity difference at the outer surface position corresponding to the inner ring of the crystallized ingot cross-section, 50mm away from the end face of the crystallized ingot. The smaller the deviation, the better the purity uniformity.

[0147] As can be seen from the table above:

[0148] (1) Compared with Example 10, it can be seen that by setting the first slide rail 221 and the second slide rail 222, the flow is blocked by the flow plate on the second slide rail in the early stage of crystallization. When the crystallized ingot grows to the area of ​​the first slide rail, the first slide rail and the second slide rail are used to block the flow at the same time, which effectively improves the purification rate and the purity uniformity of the crystallized ingot is better.

[0149] (2) Compared with Comparative Examples 1-2, Example 1 shows that compared with electromagnetic stirring, the present application uses a flow baffle 230 to block the flow, which is more effective in promoting the diffusion of impurity elements near the solid-liquid interface. At the same time, it avoids cross-contamination caused by electromagnetic stirring to drive the overall rotation. The present application can improve the purification rate.

[0150] (3) Compared with Comparative Examples 3-4, Example 1 shows that by controlling the distance between the crystallization ingot and the flow barrier 230, the present application can reduce the purification rate, purity deviation and yield, and avoid problems such as poor purity uniformity of crystallization ingot and unstable yield.

[0151] In summary, this application, by setting a flow-restricting mechanism 200 within the crystallization furnace 100, increases the relative linear velocity between the molten metal near the crystallization ingot through the relative rotation between the flow-restricting plate 230 and the crystallization ingot. Furthermore, as the crystallization ingot grows, the first driver 220 moves the flow-restricting plate 230 away from the crystallization ingot, achieving localized flow restriction—that is, acting only on the liquid phase region at the front of the solid-liquid interface. This better maintains a stable liquid surface and avoids oxidation of the molten metal and the crystallization ingot. The position of the flow-restricting plate 230 in the flow-restricting mechanism 200 is adjustable, maximizing the diffusion of impurity elements and reducing molten surface disturbance during crystallization purification, effectively improving the purity of the crystallization ingot.

[0152] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0153] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the appended claims.

Claims

1. A crystallization purification method, characterized in that, The crystallization purification method is performed using a crystallization purification device, which includes: A crystallization furnace includes a furnace body, a furnace cover, and a crystallization shaft. The furnace body is used to melt metal and contain the molten metal. The furnace cover is used to cover the furnace body. The crystallization shaft passes through the furnace cover and is disposed in the furnace body. The crystallization shaft is used for crystallization purification to form crystallized ingots. The flow-blocking mechanism includes a rotating base, a first driver, and multiple flow-blocking plates. The rotating base is disposed inside the furnace body, and the multiple flow-blocking plates are respectively disposed on the rotating base. The rotating base is used to drive the flow-blocking plates to rotate around the crystallization axis. The first driver is connected to the flow-blocking plates and is used to drive the flow-blocking plates to move in a direction away from the crystallization axis. The crystallization purification method includes: Metal is added to the furnace and heated to melt it into a molten metal, which is then kept at a constant temperature. The crystallization shaft is inserted into the molten metal, the crystallization shaft rotates and a cooling medium is introduced for crystallization purification, and a crystallization ingot is formed on the surface of the crystallization shaft; The flow-blocking mechanism is inserted into the molten metal. The rotating seat drives the flow-blocking plate to rotate around the crystallization axis. The rotation direction of the flow-blocking plate around the crystallization axis is opposite to the rotation direction of the crystallization axis. As the crystallization ingot gradually increases in size, the first driver adjusts the distance between the flow-blocking plate and the crystallization ingot to maintain the distance between the flow-blocking plate and the crystallization ingot at 20mm~100mm. After the crystallization purification is completed, the crystallization shaft is removed to obtain a crystallization ingot.

2. The crystallization purification method as described in claim 1, characterized in that, The flow-blocking plate satisfies at least one of the following conditions: (1) The flow-blocking plates are arranged at equal intervals along the circumference of the crystallization axis; (2) The number of the flow-blocking plates is 4 to 16; (3) The width of the baffle plate is 0.1 to 0.2 times the inner diameter of the furnace body.

3. The crystallization purification method according to claim 1 or 2, characterized in that, The first driver includes a plurality of slide rails disposed on the rotating base, the plurality of slide rails being arranged at circumferential intervals along the crystallization axis, and the slide rails all extending in a direction away from the crystallization axis; the flow baffles are respectively slidably disposed on the slide rails.

4. The crystallization purification method as described in claim 3, characterized in that, The slide rail includes a first slide rail and a second slide rail, wherein the distance between the first slide rail and the crystallization axis is less than the distance between the second slide rail and the crystallization axis.

5. The crystallization purification method as described in claim 3, characterized in that, The flow-blocking mechanism further includes a second driver, which is disposed on the flow-blocking plate and is used to drive the flow-blocking plate to rotate about its length.

6. The crystallization purification method as described in claim 5, characterized in that, The flow baffle is slidably mounted on the slide rail by the second driver. The first driver is used to drive the second driver to slide on the slide rail, so as to move the flow baffle away from the crystallization axis.

7. The crystallization purification method according to claim 1, characterized in that, The rotational speed of the baffle plate around the crystallization axis is 0.5 to 2 times the rotational speed of the crystallization axis.

8. The crystallization purification method according to claim 1, characterized in that, The rotation speed of the crystallization axis is 90 rpm to 270 rpm.

9. The crystallization purification method according to claim 1, characterized in that, The first driver drives the flow baffle away from the crystallization ingot at the same speed as the crystallization speed of the crystallization ingot.

10. The crystallization purification method according to claim 9, characterized in that, The crystallization rate is 50 mm / h to 200 mm / h.

11. The crystallization purification method according to any one of claims 1-2 or 7-10, characterized in that, The first driver includes a plurality of slide rails disposed on the rotating base, and the flow-blocking plate moves along the slide rails. The flow-blocking mechanism also includes a second driver, which is used to drive the flow-blocking plate to rotate about the axial direction of the flow-blocking plate.

12. The crystallization purification method according to claim 11, characterized in that, When the baffle plate is inserted into the molten metal and moves along the slide rail, the angle between the baffle plate and the slide rail is less than or equal to 15°.

13. The crystallization purification method as described in claim 11, characterized in that, When the crystallization purification is completed, the second driver drives the flow baffle to rotate. The direction of rotation of the flow baffle is the same as the direction of rotation of the crystallization shaft, and the angle between the flow baffle and the slide rail is 75°~90°.

14. The crystallization purification method according to claim 11, characterized in that, After the crystallization purification is completed, the rotation of the crystallization axis and the rotation of the baffle plate around the crystallization axis are stopped. The second driver drives the baffle plate to rotate so that the baffle plate is perpendicular to the slide rail.

15. The crystallization purification method according to claim 14, characterized in that, The rotation direction of the flow-blocking plate is the same as the rotation direction of the crystallization axis.

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