Crystallization purification device, crystallization purification method and application thereof

Abstract

The invention relates to the technical field of crystallization, and provides a crystallization purification device, a crystallization purification method and application thereof, and the crystallization purification device comprises a crystallization furnace and a flow blocking mechanism. The crystallization furnace comprises a furnace body, a furnace cover and a crystallization shaft. The flow blocking mechanism comprises a rotating seat, a first driver and a plurality of flow blocking plates, the rotating seat is arranged in the furnace body, the flow blocking plates are arranged on the rotating seat, the rotating seat is used for driving the flow blocking plates to rotate around the crystallization shaft, the first driver is connected with the flow blocking plates, and the first driver is used for driving the flow blocking plates to move in the direction away from the crystallization shaft. The flow blocking mechanism is arranged in the crystallization furnace, the relative linear speed between metal melts near the crystallization ingot is increased through relative rotation between the flow blocking plate and the crystallization ingot, diffusion of impurity elements is promoted, melt liquid level disturbance is reduced, and the purity of the crystallization ingot is effectively improved.

Description

Technical Field

[0001] The present application relates to the field of crystallization technology, and in particular to a crystallization purification device, a crystallization purification method and uses thereof. Background Art

[0002] Crystallization purification of high-purity aluminum is a process for preparing high-purity aluminum by utilizing the segregation characteristics of impurity elements during the transformation of aluminum liquid from liquid to solid. The so-called segregation refers to the phenomenon that the solid alloy or metal composition is different from the original liquid composition during the solidification process of the alloy or pure metal. Generally speaking, the content of trace impurity elements in the solidified crystal is much lower than that of the original aluminum liquid. However, during the crystallization process, the rotation of the crystallization axis causes the synchronous rotation of the molten metal in the furnace, which makes the relative linear velocity between the crystallization axis and the molten metal low, weakening the driving force for the diffusion of impurity elements from the front of the solid-liquid interface to the liquid phase, increasing the thickness of the impurity element enrichment layer, and resulting in a decrease in the removal rate of impurity elements. Summary of the invention

[0003] Based on this, an embodiment of the present application provides a crystallization purification device, a crystallization purification method and its use with good crystallization purification effect.

[0004] In a first aspect, the present application provides a crystallization purification device, the crystallization purification device comprising:

[0005] A crystallization furnace comprises a furnace body, a furnace cover and a crystallization shaft, wherein the furnace body is used to melt metal and accommodate the molten metal, the furnace cover is used to cover the furnace body, the crystallization shaft passes through the furnace cover and is arranged in the furnace body, and the crystallization shaft is used for crystallization and purification to form a crystallization ingot;

[0006] The baffle mechanism includes a rotating seat, a first driver and a plurality of baffle plates, wherein the rotating seat is arranged in the furnace body, and the plurality of baffle plates are respectively arranged on the rotating seat, the rotating seat is used to drive the baffle plates to rotate around the crystallization axis, the first driver is connected to the baffle plates, and the first driver is used to drive the baffle plates to move in a direction away from the crystallization axis.

[0007] In some embodiments, the baffles are arranged at equal intervals along the circumference of the crystallization axis.

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

[0009] In some embodiments, the width of the baffle 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 seat, the plurality of slide rails are arranged at intervals along the circumference of the crystallization axis, and the slide rails all extend in a direction away from the crystallization axis; the baffles are respectively slidably disposed on the slide rails.

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

[0012] In some embodiments, the baffle mechanism further includes a second driver, which is disposed on the baffle plate and is used to drive the baffle plate to rotate around its length direction.

[0013] In some embodiments, the baffle is slidably disposed on the slide rail via the second driver, and the first driver is used to drive the second driver to slide on the slide rail to drive the baffle to move in a direction away from the crystallization axis.

[0014] In a second aspect, the present application provides a crystallization purification method, wherein the crystallization purification method adopts the crystallization purification device as described in the first aspect, comprising:

[0015] Adding metal into the furnace body, heating and melting to form a molten metal, and keeping the molten metal warm;

[0016] Inserting the crystallization axis into the metal melt, the crystallization axis rotates and a cooling medium is introduced to perform crystallization purification, and a crystallization ingot is formed on the surface of the crystallization axis;

[0017] The baffle mechanism is inserted into the metal melt, and the rotating seat drives the baffle plate to rotate around the crystallization axis. As the crystallization ingot gradually becomes larger, the first driver adjusts the distance between the baffle plate and the crystallization ingot to maintain the distance between the baffle plate and the crystallization ingot at 20 mm to 100 mm;

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

[0019] In some embodiments, the rotation direction of the baffle driven by the rotating seat around the crystallization axis is opposite to the rotation direction of the crystallization axis.

[0020] Optionally, the rotation speed of the baffle around the crystallization axis is 0.5 to 2 times the rotation 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 speed at which the first driver drives the baffle plate away from the crystallization ingot is the same as the crystallization speed of the crystallization ingot.

[0023] Optionally, the crystallization speed is 50 mm / h~200 mm / h.

[0024] In some embodiments, the first driver includes a plurality of slide rails disposed on the rotating seat, the spoiler moves along the slide rails, and the baffle mechanism further includes a second driver, and the second driver is used to drive the spoiler to rotate around the axial direction of the spoiler.

[0025] Optionally, when the baffle is inserted into the molten metal and moves along the slide rail, an angle between the baffle 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 to rotate, the rotation direction of the baffle is the same as the rotation direction of the crystallization axis, and the angle between the baffle 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 baffle is the same as the rotation direction of the crystallization axis.

[0029] In a third aspect, the present application provides a use of the crystallization purification device as described in the first aspect, wherein the crystallization purification device is used for crystallization purification of aluminum.

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

[0031] The present application sets a flow blocking mechanism in the crystallization furnace, and increases the relative linear velocity of the metal melt near the crystallization ingot by relative rotation between the flow blocking plate and the crystallization ingot. As the crystallization ingot grows, the flow blocking plate is driven by the first driver to move in a direction away from the crystallization ingot, thereby realizing local flow blocking, that is, only acting on the liquid phase region in front of the solid-liquid interface, which can better maintain the liquid level stable and avoid oxidation of the metal melt and the crystallization ingot. The position of the flow blocking plate in the flow blocking mechanism of the present application is adjustable, which can maximize the diffusion of impurity elements during the crystallization purification process, reduce the disturbance of the melt liquid level, and effectively improve the purity of the crystallization ingot. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A diagram showing the initial state of a crystallization device in crystallization purification provided in one embodiment of the present application;

[0033] Figure 2 A state diagram of a crystallization device provided in one embodiment of the present application when crystallization purification is completed;

[0034] Figure 3 This is an arrangement diagram of the slide rails on the rotating seat provided in one embodiment of the present application;

[0035] Figure 4 This is a diagram of the rotation state of the spoiler provided in one embodiment of the present application under the driving action of the second driver.

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

[0037] Below in conjunction with the embodiments and examples, the present application is further described in detail. These embodiments and examples are only used to illustrate the present application and are not used to limit the scope of the present application. The purpose of providing these embodiments and examples is to make the understanding of 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 changes or modifications without violating the connotation of the present application, and the equivalent form obtained also falls within the protection scope of the present application. In addition, in the description below, a large number of specific details are given in order to provide a more comprehensive 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 those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0039] In this application, "optionally", "optional", and "optional" mean optional or dispensable, that is, any one of the two parallel schemes of "yes" or "no". If multiple "options" appear in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "optional" is independent.

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

[0041] In the present application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0042] In the present application, when it comes to a numerical interval (i.e., a numerical range), unless otherwise specified, the distribution of the optional numerical values ​​in the numerical interval is considered to be continuous, and includes the two numerical endpoints (i.e., the minimum and maximum values) of the numerical interval, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to an integer in the numerical interval, it includes the two endpoint integers of the numerical range, and each integer between the two endpoints, which is equivalent to directly listing each integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be combined. In other words, unless otherwise specified, the numerical range disclosed in the present application should be understood to include any and all sub-ranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. "Numerical interval" allows for a broad range of quantitative intervals such as percentage intervals, ratio intervals, and ratio intervals.

[0043] All documents mentioned in this application are cited as references in this application, just as each document is cited as reference separately. Unless they conflict with the application purpose and / or technical solution of this application, the cited documents involved in this application are cited with all contents and all purposes. When the cited documents are involved in this application, the definitions of relevant technical features, terms, nouns, phrases, etc. in the cited documents are also cited. When the cited documents are involved in this application, the examples and preferred methods of the cited relevant technical features can also be incorporated into this application as references, but are limited to the implementation of this application. It should be understood that when the cited content conflicts with the description in this application, the present application shall prevail or be modified adaptively according to the description of this application.

[0044] In the traditional technology, during the crystallization and purification process of the crystallization furnace, the molten metal rotates synchronously with the rotation of the crystallization axis, which reduces the relative linear velocity between the surface of the crystallization ingot and the molten metal, weakens the driving force for the diffusion of impurity elements from the front of the solid-liquid interface to the liquid phase, increases the thickness of the impurity element enrichment layer, and leads to a decrease in the removal rate of impurity elements. In addition, electromagnetic stirring is used in the traditional technology to increase the relative linear velocity between the molten metal and the crystallization ingot. However, during the electromagnetic stirring process, stirring is applied to the entire molten metal, which easily causes the liquid level of the molten metal to fluctuate, and then causes the molten metal to oxidize, affecting the purification yield. In addition, the electromagnetic stirring method is difficult to further increase the relative linear velocity between the molten metal and the crystallization ingot, and the crystallization purification effect is poor.

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

[0046] Among them, the crystallization furnace 100 includes a furnace body 110, a furnace cover 120 and a crystallization axis 130. The furnace body 110 is used to melt metal and accommodate the molten metal, the furnace cover 120 is used to cover the furnace body 110, and the crystallization axis 130 passes through the furnace cover 120 and is arranged in the furnace body 110. The crystallization axis 130 is used for crystallization and purification to form a crystallization ingot.

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

[0048] like Figure 1 As shown, the baffle plate 230 is kept away from the crystallization axis 130 in the initial stage of crystallization purification. Figure 2 As shown, when the crystallization purification is completed, the baffle 230 is kept away from the crystallization ingot.

[0049] The present application sets a flow blocking mechanism 200 in the crystallization furnace 100, and increases the relative linear velocity of the metal melt near the crystallization ingot by relative rotation between the flow blocking plate 230 and the crystallization ingot, and as the crystallization ingot grows, the flow blocking plate 230 is driven by the first driver 220 to move in a direction away from the crystallization ingot, thereby realizing local flow blocking, that is, only acting on the liquid phase region in front of the solid-liquid interface, which can better maintain the liquid level stable and avoid the problem of oxidation of the metal melt and the crystallization ingot. The position of the flow blocking plate 230 in the flow blocking mechanism 200 of the present application is adjustable, which can maximize the diffusion of impurity elements during the crystallization purification process, reduce the disturbance of the melt liquid surface, and effectively improve the purity of the crystallization ingot.

[0050] It can be understood that the crystallization furnace 100 in the present application also includes a driver for driving the crystallization shaft 130 to rotate. A rotating motor can be connected to the crystallization shaft 130 through gears to synchronously drive the crystallization shaft 130 to rotate, and the adjustable speed supports continuously variable speed operation.

[0051] It is understood that the crystallization shaft 130 has a cooling channel, and a cooling medium can be introduced into the cooling channel to ensure that a crystallization ingot is formed on the crystallization shaft 130. Optionally, the cooling channel can be a heat dissipation copper tube with high thermal conductivity and fins. Among them, the cooling medium can be introduced into the cooling channel through a cooling pump, and the cooling pump can output cooling fluid media with different flow rates and pressures.

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

[0053] In some embodiments, the number of the baffles 230 is 4 to 16, for example, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 or 16. The present application selects the number and arrangement of the baffles 230 as above, which can effectively hinder the flow of aluminum liquid while reducing the disturbance of the melt surface, thereby avoiding the enrichment of impurity elements near the solid-liquid interface and the occurrence of oxide slag.

[0054] In some embodiments, the width of the baffle 230 is 0.1 to 0.2 times the inner diameter of the furnace body 110, for example, 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 230 selected in the present application increases the relative linear velocity of the solid-liquid phase movement while achieving the maximum baffle stroke, which can take into account both the purification effect and the actual yield.

[0055] In some embodiments, Figure 3As shown, the first driver 220 includes a plurality of slide rails disposed on the rotating seat 210, the plurality of slide rails are arranged at intervals along the circumference of the crystallization axis 130, and the slide rails all extend in a direction away from the crystallization axis 130; the spoiler plates 230 are respectively slidably disposed on the slide rails. Optionally, a slider is disposed on each of the slide rails, and the spoiler plates 230 are disposed on the slider, and the slider drives the spoiler plates 230 to slide on the slide rails.

[0056] In the present application, the baffle plate 230 is set on a slide rail for sliding, which can ensure the movement stability of the baffle plate 230 during the rotation process, so that the movement direction of the baffle plate 230 is away from the crystallization ingot, so that during the growth of the crystallization ingot, the metal melt near the crystallization ingot is always blocked, ensuring that the crystallization and purification are carried out stably.

[0057] Alternatively, Figure 3 As shown, the slide rail includes a first slide rail 221 and a second slide rail 222, and 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. In the present application, by setting two slide rails, when the diameter of the crystallization ingot is small, there is no need to set more baffles 230 in the circumference of the crystallization ingot for flow obstruction, and too many baffles 230 may cause the volume of the metal solution around the crystallization ingot to be small, affecting the initial crystallization effect. When the crystallization ingot grows to a certain extent, for example, it grows to the second slide rail 222, due to the large volume of the crystallization ingot, if only the baffle 230 on the first slide rail 221 is used for flow obstruction, it may cause the relative linear velocity at the solid-liquid interface to be small. Therefore, the baffle 230 on the second slide rail 222 is introduced to block the flow to improve the flow blocking effect.

[0058] It is understandable that the first driver 220 has the driving capability to drive the spoiler 230 to slide on the slide rail, and for example, may also include a telescopic cylinder or a stepping motor to adjust the movement speed of the spoiler 230 on the slide rail. Furthermore, in order to ensure that the movement speeds of the spoilers 230 are consistent, a controller may be provided to ensure that the movement speeds of the telescopic cylinders are the same.

[0059] In some embodiments, Figure 4 As shown, the blocking mechanism 200 further includes a second driver 240, which is disposed on the blocking plate 230 and is used to drive the blocking plate 230 to rotate about the length direction. Optionally, when the blocking plate 230 slides on the slide rail through the slider, the second driver 240 can be disposed on the blocking plate 230 and connected to the slider, so that the blocking plate 230 is driven to rotate through the second driver 240.

[0060] It can be understood that the length direction of the spoiler 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, the length direction of the spoiler 230 is the vertical direction perpendicular to the horizontal plane.

[0061] The present application sets a second driver 240 to drive the baffle plate 230 to rotate, so that the angle of the baffle plate 230 can be adjusted according to different crystallization and purification stages, thereby achieving different blocking states of the baffle plate 230 for the crystallization ingot and ensuring the optimal effect of crystallization and purification in each stage.

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

[0063] In some embodiments, the rotation axis of the spoiler 230 under the action of the second driver 240 can be any direction along the length of the spoiler 230. For example, the spoiler 230 can be rotated around the axis in the length direction, or around one long side of the spoiler 230 as the axis.

[0064] In some embodiments, the spoiler 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 to drive the spoiler 230 to move in a direction away from the crystallization axis 130 .

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

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

[0067] In some embodiments, the spoiler 230 may be a rectangular sheet structure. Optionally, the spoiler 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 230 may be the same as the length of the crystallization axis 130 immersed in the metal melt.

[0069] In some embodiments, the rotating seat 210 is disposed on the furnace cover 120 , and the baffle 230 can be inserted into the metal melt when the furnace cover 120 is installed.

[0070] The second aspect of the present application provides a crystallization purification method, which uses the crystallization purification device as described in the first aspect, including:

[0071] Adding metal into the furnace body 110 to heat and melt to form a molten metal, and keeping the molten metal warm;

[0072] The crystallization shaft 130 is inserted into the metal melt, the crystallization shaft 130 rotates and a cooling medium is introduced to perform crystallization and purification, and a crystallization ingot is formed on the surface of the crystallization shaft 130;

[0073] The baffle mechanism 200 is inserted into the metal melt, and the rotating seat 210 drives the baffle plate 230 to rotate around the crystallization axis 130. As the crystallization ingot gradually increases, the first driver 220 adjusts the distance between the baffle plate 230 and the crystallization ingot to maintain the distance between the baffle plate 230 and the crystallization ingot at 20 mm to 100 mm.

[0074] After the crystallization and purification are completed, the crystallization shaft 130 is taken out to obtain a crystallization ingot.

[0075] During the crystallization and purification process of the present application, the baffle plate 230 rotates relative to the crystallization shaft 130, and the relative distance between the baffle plate 230 and the crystallization ingot is controlled, thereby achieving local 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 liquid level of the molten metal, reducing the risk of oxidation.

[0076] The present application controls the distance between the baffle 230 and the crystallization ingot as above, which can significantly improve the crystallization purification effect. If the distance is relatively close, the crystallization ingot may contact the baffle 230, causing damage to the crystallization ingot, and there may also be a problem of the baffle and the crystallization ingot being stuck, causing the purification to be interrupted. If the distance is relatively far, it may cause the relative linear velocity at the solid-liquid contact interface to be small, the crystallization purification effect is poor, and it may also affect the yield of the crystallization ingot.

[0077] It should be noted that in the present application, the crystallization ingot and the metal melt have a relative speed at the contact surface, which may be that the rotation speed of the baffle 230 around the crystallization axis 130 is different from the rotation speed of the crystallization axis 130, thereby causing a speed difference between the metal melt and the crystallization axis 130, and realizing the relative rotation of the crystallization ingot and the metal melt. It can also be that the rotation direction of the baffle 230 around the crystallization axis 130 is different from the rotation direction of the crystallization axis 130. In some embodiments, the rotating seat 210 drives the baffle 230 to rotate around the crystallization axis 130 in the opposite direction to the rotation direction of the crystallization axis 130. The present application utilizes the rotation direction of the crystallization axis 130 to be opposite to the revolution direction of the baffle 230, thereby effectively increasing the relative linear velocity at the solid-liquid interface between the metal melt and the crystallization 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 crystallization ingot.

[0078] Optionally, the rotation speed of the baffle 230 around the crystallization axis 130 is 0.5 to 2 times the rotation speed of the crystallization axis 130, for example, it can be 0.5 times, 0.6 times, 0.7 times, 0.8 times, 0.9 times, 1.0 times, 1.1 times, 1.2 times, 1.3 times, 1.4 times, 1.5 times, 1.6 times, 1.7 times, 1.8 times, 1.9 times or 2.0 times. The present application selects the rotation speed of the crystallization axis 130 and the rotation speed of the baffle 230 around the crystallization axis 130 as above, which can promote the diffusion driving force and speed of the impurity elements from the solid phase to the liquid phase. If the rotation speed of the baffle 230 is relatively fast, it may cause peripheral disturbance of the melt liquid surface, aggravating the oxidation slag formation of the aluminum liquid surface.

[0079] Optionally, the rotation speed of the crystallization shaft 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 speed at which the first driver 220 drives the baffle plate 230 away from the crystallization ingot is the same as the crystallization speed of the crystallization ingot. The present application controls the speed at which the baffle plate 230 moves away from the crystallization ingot according to 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 baffle plate 230 and the crystallization ingot from being too far or too close to affect the purification effect.

[0081] Optionally, the crystallization speed is 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 speed can be reasonably selected according to the material of the metal melt 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 , and the spoiler 230 moves along the slide rails. The spoiler mechanism 200 also includes a second driver 240 , and the second driver 240 is used to drive the spoiler 230 to rotate around the axial direction of the spoiler 230 .

[0083] Optionally, when the spoiler 230 is inserted into the metal melt and moves along the slide rail, the angle between the spoiler 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 0°. It is understood that the angle between the spoiler 230 and the slide rail in the present application refers to the angle between the width direction of the spoiler 230 and the extension direction of the slide rail.

[0084] As described above, the present application selects the angle of the baffle plate 230 during the movement process, and the width direction of the baffle plate 230 is basically perpendicular to the tangent direction of the crystallization axis 130, which can maximally hinder the flow rate of the molten metal, ensure the baffle effect of the baffle plate 230, effectively increase the relative linear velocity of the solid-liquid interface, and promote the effective diffusion of impurity elements.

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

[0086] When the crystallization purification is completed, the angle between the baffle 230 and the slide rail is adjusted as above, so that the surface slag in the molten metal during the crystallization process (referring to the oxidation of the molten aluminum to form alumina floating on the surface of the melt due to the disturbance of the molten aluminum, commonly known as slag) can be guided to the wall of the furnace body 110 to avoid contact with the crystallization ingot, thereby ensuring the purity of the crystallization ingot.

[0087] In some embodiments, after the 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, and the second driver 240 drives the baffle plate 230 to rotate so that the baffle plate 230 is 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] The present application adjusts the baffle plate 230 as described above after the crystallization is completed to prevent the oxide between the crucible wall and the baffle plate from adhering to the surface of the crystallization ingot when the crystallization ingot is taken out of the metal melt.

[0089] like Figure 4 As shown, it shows the state of the baffle plate 230 when the crystallization purification is completed and after the completion. Among them, during the crystallization purification, Figure 4 The angle between the middle baffle plate 230 and the slide rail is 0°. When the crystallization purification is completed, the baffle plate 230 rotates 45° to guide the oxides in the metal melt to the wall surface of the furnace body 110. After the crystallization purification is completed, the baffle plate 230 rotates another 45° to make the angle between the baffle plate 230 and the slide rail 90°, and the crystallized ingot is taken out.

[0090] In some embodiments, when the baffle 230 is inserted into the molten metal, the baffle 230 may be placed above the surface of the molten metal for standing. Optionally, the distance between the baffle 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 230 is less than or equal to 10 mm / s. The present application preheats the baffle 230 by placing the baffle 230 above the surface of the molten metal for a period of time, thereby avoiding directly inserting the baffle 230 into the aluminum liquid, which affects the service life of the baffle 230.

[0091] In some embodiments, the difference between the holding temperature and the liquidus temperature of the molten metal is 30° C. to 60° C., for example, 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 the material begins to change from liquid to solid.

[0092] Exemplarily, a method for crystallizing and purifying aluminum using the above-mentioned crystallization purification device is provided, comprising the following steps:

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

[0094] S2. Suspend the baffle plate 230 above the metal melt, keep the lower end of the baffle plate 230 above the metal melt liquid surface by 50 mm, let it stand for 1 min to 5 min, and then slowly insert the baffle plate 230 into the metal melt at a speed not exceeding 10 mm / s.

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

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

[0097] S5. Start the baffle mechanism 200, and the baffle plate 230 moves along the slide rail, always maintaining a distance between the baffle plate 230 and the surface of the crystallization ingot of 20 mm to 100 mm, and the rotation speed of the baffle plate 230 around the crystallization axis 130 is 0.5 to 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 baffle plate 230 moves along the slide rail in a direction away from the crystallization ingot, maintaining a distance between the baffle plate 230 and the surface of the crystallization ingot.

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

[0099] S7: After the crystallization and purification is finished, the rotation of the crystallization shaft 130 and the revolution of the baffle plate 230 are stopped, and the second driver 240 drives the baffle plate 230 to rotate again, and the rotation direction is consistent with the rotation direction of the crystallization shaft 130, so that the baffle plate 230 and the slide rail are perpendicular, and then the crystallization ingot is slowly lifted out of the metal melt, and the cooling system is closed to complete the crystallization and purification.

[0100] Repeat steps S1-S7 to continuously repeat the purification.

[0101] The third aspect of the present application provides a use of the crystallization purification device as described in the first aspect, and the crystallization purification device is used for crystallization purification of aluminum.

[0102] The embodiments of the present application will be described in detail below in conjunction with examples. It should be understood that these examples are only used to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods for which specific conditions are not specified in the following examples are preferably referred to the guidance provided in the present application, and can also be based on the experimental manual or normal conditions in this area, can also be based on 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 device, 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, and the inner diameter of the furnace body 110 is 720 mm. The baffle mechanism 200 includes a rotating seat 210, a first driver 220, a second driver 240 and four baffles 230, the width of the baffle 230 is 108 mm, the rotating seat 210 is arranged 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 baffles 230 are correspondingly arranged on the slide rails, and the baffles 230 are slidably arranged on the slide rails through the second driver 240, the first driver 220 is used to drive the second driver 240 to slide along the slide rails, and drive the baffles 230 to move along the slide rails, and the second driver 240 is used to drive the baffles 230 to rotate.

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

[0107] S1. Add an aluminum ingot with a mass purity of 5N (99.999%) into the furnace body 110, heat and melt it, and keep it at 710° C. for 30 minutes.

[0108] S2. Suspend the baffle plate 230 above the metal melt, keep the lower end of the baffle plate 230 at 50 mm above the metal melt surface, and after standing for 3 minutes, slowly insert the baffle plate 230 into the metal melt at a speed of 5 mm / s, with the angle between the baffle plate 230 and the slide rail being 0°.

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

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

[0111] S5. Start the baffle mechanism 200, and the baffle plate 230 moves along the slide rail, always maintaining a distance of 60 mm between the baffle plate 230 and the surface of the crystallization ingot, and the rotation speed of the baffle plate 230 around the crystallization axis 130 is 120 rpm, 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 baffle plate 230 moves along the slide rail in a direction away from the crystallization ingot at the crystallization speed, maintaining the distance between the baffle plate 230 and the surface of the crystallization ingot.

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

[0113] S7: After 90 minutes of crystallization purification, the rotation of the crystallization shaft 130 and the revolution of the baffle plate 230 are stopped, and the second driver 240 drives the baffle plate 230 to rotate again, and the rotation direction is consistent with the rotation direction of the crystallization shaft 130, so that the baffle plate 230 is perpendicular to the slide rail, and then the crystallization ingot is slowly lifted out of the metal melt, and the cooling system is closed to complete the crystallization purification.

[0114] Example 2

[0115] The crystallization purification device of Example 1 is used to crystallize and purify aluminum, except that the distance between the baffle 230 and the crystallization ingot is 30 mm.

[0116] Example 3

[0117] The crystallization purification device of Example 1 is used to crystallize and purify aluminum, except that the distance between the baffle 230 and the crystallization ingot is 100 mm.

[0118] Example 4

[0119] The crystallization purification device of Example 1 is used to crystallize and purify aluminum, except that the revolution speed of the baffle 230 is 60 rpm.

[0120] Example 5

[0121] The crystallization purification device of Example 1 is used to crystallize and purify aluminum, except that the revolution speed of the baffle 230 is 240 rpm.

[0122] Example 6

[0123] The crystallization and purification device of Example 1 is used to crystallize and purify aluminum, with the difference that during the crystallization and purification process, the angle between the baffle plate 230 and the slide rail is 15° when the metal melt is inserted, and the angle between the baffle plate 230 and the slide rail is 75° when the crystallization is completed.

[0124] Example 7

[0125] The crystallization purification device of Example 1 is used to crystallize and purify aluminum, except that the number of slide rails is 8, the number of spoilers 230 is 8, and the orbital speed of the spoiler 230 is 60 rpm.

[0126] Example 8

[0127] The crystallization purification device of Example 1 is used to crystallize and purify aluminum, except that the number of slide rails is 8, the number of baffles 230 is 8, the revolution speed of the baffle 230 is 60 rpm, and the distance between the baffle 230 and the crystallization ingot is maintained at 30 mm.

[0128] Example 9

[0129] The crystallization purification device of Example 1 is used to crystallize and purify aluminum, except that the number of slide rails is 8, the number of baffles 230 is 8, the revolution speed of the baffle 230 is 0 rpm, and the distance between the baffle 230 and the crystallization ingot is maintained at 30 mm.

[0130] Example 10

[0131] The crystallization purification device of Example 1 is used to crystallize and purify aluminum, the difference being that the slide rails include 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 90 mm, and the distance between the second slide rail 222 and the crystallization axis 130 is 60 mm.

[0132] Comparative Example 1

[0133] The crystallization purification device of Example 1 is used to crystallize and purify aluminum, except that the baffle 230 is not provided.

[0134] Comparative Example 2

[0135] The crystallization purification device of Example 1 is used to crystallize and purify aluminum, except that the flow blocking mechanism 200 is replaced by an electromagnetic stirrer, and the working parameters of the electromagnetic stirrer are an electromagnetic frequency of 45 Hz and a current intensity of 950A.

[0136] Comparative Example 3

[0137] The crystallization purification device of Example 1 was used to crystallize and purify aluminum, except that the distance between the baffle 230 and the crystallization ingot was maintained at 250 mm.

[0138] Comparative Example 4

[0139] The crystallization purification device of Example 1 was used to crystallize and purify aluminum, except that the distance between the baffle 230 and the crystallization ingot was maintained at 10 mm.

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

[0141] Table 1

[0142]

[0143] Note:

[0144] The yield, i.e. the actual yield of crystallization ingots = weight of crystallization ingot / weight of melt in the crucible.

[0145] The 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 the purity of the crystallization ingot. In this embodiment, it refers to the purity difference at the corresponding outer surface position within the circular ring of the cross-section of the crystallization ingot at a distance of 50 mm from the end face of the crystallization ingot. The smaller the deviation, the better the purity uniformity.

[0147] From the above table we can see that:

[0148] (1) Compared with Example 10, it can be seen that the present application sets a first slide rail 221 and a second slide rail 222. In the early stage of crystallization, the baffle plate on the second slide rail is used to block the flow. When the crystallization ingot grows to the first slide rail area, the first slide rail and the second slide rail are used to block the flow at the same time, thereby effectively improving the purification rate and improving the purity uniformity of the crystallization ingot.

[0149] (2) Compared with comparative examples 1-2, it can be seen that compared with electromagnetic stirring, the present application uses a baffle 230 for flow blocking, which is more effective in promoting the diffusion of impurity elements near the solid-liquid interface, while avoiding cross contamination caused by the overall rotation driven by electromagnetic stirring. The present application can improve the purification rate.

[0150] (3) By comparing Example 1 with Comparative Examples 3-4, it can be seen that the present application controls the distance between the crystallization ingot and the baffle 230, which can control the purification rate, purity deviation and yield rate, and avoid problems such as poor purity uniformity of the crystallization ingot and unstable yield rate.

[0151] In summary, the present application sets a flow blocking mechanism 200 in the crystallization furnace 100, and increases the relative linear velocity between the metal melt near the crystallization ingot by the relative rotation between the flow blocking plate 230 and the crystallization ingot, and as the crystallization ingot grows, the flow blocking plate 230 is driven by the first driver 220 to move in a direction away from the crystallization ingot, thereby realizing local flow blocking, that is, only acting on the liquid phase region in front of the solid-liquid interface, which can better maintain the liquid level stable and avoid the problem of oxidation of the metal melt and the crystallization ingot. The position of the flow blocking plate 230 in the flow blocking mechanism 200 of the present application is adjustable, which can maximize the diffusion of impurity elements during the crystallization purification process, reduce the disturbance of the melt liquid level, and effectively improve the purity of the crystallization ingot.

[0152] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described 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 above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the application. It should be noted that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A crystallization purification device, characterized in that: The crystallization purification device comprises: A crystallization furnace comprises a furnace body, a furnace cover and a crystallization shaft, wherein the furnace body is used to melt metal and accommodate the molten metal, the furnace cover is used to cover the furnace body, the crystallization shaft passes through the furnace cover and is arranged in the furnace body, and the crystallization shaft is used for crystallization and purification to form a crystallization ingot; The baffle mechanism includes a rotating seat, a first driver and a plurality of baffle plates, wherein the rotating seat is arranged in the furnace body, and the plurality of baffle plates are respectively arranged on the rotating seat, the rotating seat is used to drive the baffle plates to rotate around the crystallization axis, the first driver is connected to the baffle plates, and the first driver is used to drive the baffle plates to move in a direction away from the crystallization axis.

2. The crystallization purification device according to claim 1, characterized in that The spoiler meets at least one of the following conditions: (1) The baffles are arranged at equal intervals along the circumference of the crystallization axis; (2) The number of the spoilers is 4 to 16; (3) The width of the baffle is 0.1 to 0.2 times the inner diameter of the furnace body.

3. The crystallization purification device according to claim 1 or 2, characterized in that: The first driver comprises a plurality of slide rails disposed on the rotating seat, the plurality of slide rails are arranged at intervals along the circumference of the crystallization axis, and the slide rails all extend in a direction away from the crystallization axis; the baffles are respectively slidably disposed on the slide rails; Optionally, the slide rail includes a first slide rail and a second slide rail, and the distance between the first slide rail and the crystallization axis is smaller than the distance between the second slide rail and the crystallization axis.

4. The crystallization purification device according to claim 3, characterized in that The baffle mechanism further includes a second driver, which is disposed on the baffle plate and is used to drive the baffle plate to rotate around its length direction; Optionally, the baffle is slidably disposed on the slide rail via the second driver, and the first driver is used to drive the second driver to slide on the slide rail, so as to drive the baffle to move in a direction away from the crystallization axis.

5. A crystallization purification method, characterized in that: The crystallization purification method adopts the crystallization purification device according to any one of claims 1 to 4, comprising: Adding metal into the furnace body, heating and melting to form a molten metal, and keeping the molten metal warm; Inserting the crystallization axis into the metal melt, the crystallization axis rotates and a cooling medium is introduced to perform crystallization purification, and a crystallization ingot is formed on the surface of the crystallization axis; The baffle mechanism is inserted into the metal melt, and the rotating seat drives the baffle plate to rotate around the crystallization axis. As the crystallization ingot gradually becomes larger, the first driver adjusts the distance between the baffle plate and the crystallization ingot to maintain the distance between the baffle plate and the crystallization ingot at 20 mm to 100 mm; After the crystallization purification is completed, the crystallization shaft is taken out to obtain a crystallization ingot.

6. The crystallization purification method according to claim 5, characterized in that The rotating seat drives the baffle plate to rotate around the crystallization axis in a direction opposite to the rotation direction of the crystallization axis; Optionally, the rotation speed of the baffle around the crystallization axis is 0.5 to 2 times the rotation speed of the crystallization axis; Optionally, the rotation speed of the crystallization axis is 90 rpm to 270 rpm.

7. The crystallization purification method according to claim 5, characterized in that The speed at which the first driver drives the baffle plate away from the crystallization ingot is the same as the crystallization speed of the crystallization ingot; Optionally, the crystallization speed is 50 mm / h~200 mm / h.

8. The crystallization purification method according to any one of claims 5 to 7, characterized in that: The first driver comprises a plurality of slide rails arranged on the rotating seat, the baffle plate moves along the slide rails, and the baffle mechanism further comprises a second driver, the second driver is used to drive the baffle plate to rotate around the axial direction of the baffle plate; Optionally, when the baffle is inserted into the molten metal and moves along the slide rail, an angle between the baffle and the slide rail is less than or equal to 15°; Optionally, when the crystallization purification is completed, the second driver drives the baffle to rotate, the rotation direction of the baffle is the same as the rotation direction of the crystallization axis, and the angle between the baffle and the slide rail is 75°~90°.

9. The crystallization purification method according to claim 8, 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, and the second driver drives the baffle plate to rotate so that the baffle plate is perpendicular to the slide rail; Optionally, the rotation direction of the baffle is the same as the rotation direction of the crystallization axis.

10. Use of the crystallization purification device according to any one of claims 1 to 4, characterized in that: The crystallization purification device is used for crystallization purification of aluminum.

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