Anode action execution method in rare earth electrolytic cell and anode automatic control electrolytic cell

Abstract

A method for executing anode actions in a rare earth electrolytic cell and an anode automatic control electrolytic cell belong to the field of rare earth electrolysis. The method for executing anode actions in a rare earth electrolytic cell, in the rare earth electrolysis process, according to the anode consumption, adjusts the movement direction of the anode through full freedom, forms a gradient pole distance with large pole distance on the molten salt surface and small pole distance inside the molten salt for electrolysis; wherein, the anode action includes moving the anode closer to the cathode along the X-axis, moving the anode along the Z-axis toward the inside of the molten salt, reciprocating the anode along the Y-axis on both sides, rotating with the center point of the top surface of the anode as a fixed point and the Z-axis as the axis, swinging in the YZ plane with the center point of the top surface of the anode as a fixed point, and swinging in the plane formed by the XZ with the center point of the top surface of the anode as a fixed point, or a combination of several action modes. This method can improve the life of the anode, reduce the residual pole rate, improve the current efficiency, and reduce energy consumption.

Description

Technical Field

[0001] The invention belongs to the field of rare earth electrolysis, and in particular relates to an anode action execution method in a rare earth electrolytic cell and an anode automatic control electrolytic cell. Background Art

[0002] Rare earth metals are extremely precious among natural resources. They are non-renewable resources with scarce reserves and high processing difficulty. They can be used in many fields and are also called "universal earth". Molten salt electrolysis is an important method for producing rare earth metals. At present, rare earth molten salt electrolysis mainly adopts an upper plug-in electrolysis structure, using a cylindrical cathode and a rectangular anode or an arc-shaped anode. The cathode is inserted into the center of the electrolytic cell and the anode is inserted around. The positions of the cathode and anode are fixed and cannot be adjusted automatically. As the electrolysis process proceeds, the anode is continuously consumed, but the anode consumption is uneven, with large consumption in the center and slow consumption on both sides. In addition, the current electrolysis process is equipolar electrolysis, with low current efficiency, generally between 60% and 75%, and a high residual pole rate. This is because the anode part at the three-phase interface is subjected to the combined effects of air oxidation, electrochemical reaction, and mechanical scouring, which will be consumed first or even broken, resulting in the anode being unable to continue to be used.

[0003] Patents CN203923410U and CN105088284B invented a method of changing the pole distance by adjusting the movement of the anode, but they can only make the anode move towards or away from the cathode, and the pole distance remains uniform and equal. Although the problem of increased pole distance due to anode consumption can be avoided, the problem of uneven anode consumption cannot be solved, and the current efficiency and anode utilization cannot be improved. Patents CN105543899A and CN209039603U invented an automatic lifting system for adjusting the cathode insertion depth, but they cannot affect the consumption of the anode. Summary of the invention

[0004] In view of the above-mentioned deficiencies, the present invention provides an anode action execution method in a rare earth electrolytic cell and an anode automatic control electrolytic cell, by controlling the movement of the anode in the rare earth electrolytic cell, adjusting the movement direction of the anode with full freedom, changing the pole distance between the anode and the cathode, so that the anode in a specific area (the area with slower consumption) is close to the cathode, accelerating its consumption and achieving the purpose of uniform consumption.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A method for executing anode action in a rare earth electrolytic cell, in the rare earth electrolysis process, according to the anode consumption, the movement direction of the anode is adjusted by full freedom, so as to form a gradient distance with a large distance on the molten salt surface and a small distance inside the molten salt for electrolysis; wherein the movement direction of the anode is adjusted by full freedom, with the symmetry axis vertical to the top surface of the anode as the Z axis, the line connecting the anode and the cathode on the horizontal plane as the X axis, and the direction perpendicular to the X axis on the horizontal plane as the Y axis;

[0007] The movement of the anode includes one of the following: bringing the anode closer to the cathode along the X-axis, moving the anode along the Z-axis toward the inside of the molten salt, moving the anode back and forth along the Y-axis, rotating with the Z-axis as the axis with the center point of the top surface of the anode as the fixed point, swinging in the YZ plane with the center point of the top surface of the anode as the fixed point, and swinging in the plane formed by the XZ plane with the center point of the top surface of the anode as the fixed point, or a combination of several movement modes.

[0008] The anode moves closer to the cathode along the X-axis, so that the anode as a whole moves closer to the center of the electrolytic cell. The moving speed is the same as the anode consumption speed during the electrolysis process, ensuring that the pole distance remains unchanged and does not change with the consumption of the anode.

[0009] The anode moves along the Z-axis toward the inside of the molten salt. In order to move the anode toward the inside of the molten salt, the moving speed matches the anode consumption speed.

[0010] The anode moves back and forth along the Y axis in a direction perpendicular to the line connecting the anode and the cathode, and the movement amplitude is less than 30% of the length of the top surface of the anode in the Y axis direction.

[0011] The rotation with the center point of the top surface of the anode as the fixed point and the Z axis as the axis refers to periodic uniform rotation with a rotation angle of -30° to 30°; wherein 0° is when the anode coincides with the initial unrotated position.

[0012] The swinging in the YZ plane with the center point of the anode top surface as a fixed point refers to periodic and uniform swinging on the plane formed by YZ, with the axis of the swing being the X axis and the swing angle being -30° to 30°; wherein 0° coincides with the initial non-swung position of the anode.

[0013] The swinging in the plane formed by XZ with the center point of the top surface of the anode as the fixed point means that it can rotate from the Z axis to the X axis, with the axis of rotation being the Y axis. After rotating to a certain angle, it no longer moves in this direction during the electrolysis process, wherein the rotation angle is between 0 and 45°, and finally a large polar distance is formed on the surface of the molten salt and a small polar distance is formed inside the molten salt; wherein 0° coincides with the initial non-swinging position of the anode, that is, it is equal polar distance electrolysis at this time.

[0014] The present invention discloses an anode automatic control rare earth electrolytic cell, comprising an electrolytic cell body, a cathode and an anode, and also comprising a conductive anode clamp for clamping the anode and an actuator for controlling the movement of the anode;

[0015] The actuator can realize the anode action mode, including moving the anode closer to the cathode along the X-axis, moving the anode along the Z-axis toward the inside of the molten salt, moving the anode back and forth along the Y-axis, rotating with the Z-axis as the axis with the center point of the top surface of the anode as the fixed point, swinging in the YZ plane with the center point of the top surface of the anode as the fixed point, and swinging in the plane formed by the XZ plane with the center point of the top surface of the anode as the fixed point, or a combination of several action modes.

[0016] The conductive anode fixture is connected to the anode and fixes the anode, and the conductive anode fixture is connected to the actuator;

[0017] When the actuator is an actuator for realizing full-degree-of-freedom adjustment of the anode, the actuator includes an omnidirectional movable base, a Z-direction lifting rod is connected above the omnidirectional movable base, a first motor is fixedly connected above the Z-direction lifting rod, a motor shaft of the first motor is parallel to the X-axis or the Y-axis, an output end of the motor shaft of the first motor is fixedly connected to the second motor, a motor shaft of the second motor is parallel to the Y-axis or the X-axis, and the motor shaft of the first motor is perpendicular to the motor shaft of the second motor; in the actuator, the omnidirectional movable base is used to realize that the actuator drives the conductive anode fixture to move in the X-axis and Y-axis, and rotate around the Z-axis; the Z-direction lifting rod is used to realize that the actuator drives the conductive anode fixture to move in the Z-axis, and the motor shaft of the first motor and the motor shaft of the second motor are respectively used to realize that the actuator drives the conductive anode fixture to rotate around the X-axis and around the Y-axis.

[0018] More specifically, the motor shaft of the second motor is connected to the conductive anode fixture, and the anode action is performed through independent or combined execution of the actuator.

[0019] When the actuator is used to realize a certain action mode of the anode, the structural components that realize other action modes can be selectively removed.

[0020] By adopting the above-mentioned anode action execution method in the rare earth electrolytic cell, the current efficiency of the rare earth electrolytic cell automatically controlled by the anode is greater than 80%, and the utilization rate of the anode is increased by 15%.

[0021] Compared with the prior art, the present invention has the following characteristics and beneficial effects:

[0022] (1) Through the multi-degree-of-freedom adjustment of the anode, a gradient electrode distance electrolysis with a large electrode distance at the top and a small electrode distance inside the molten salt can be formed, which greatly improves the current efficiency. The current efficiency is between 80% and 95%, and the average current efficiency is greater than 80%, thereby reducing the energy consumption per unit mass of product;

[0023] (2) By adjusting the movement direction of the anode with full freedom, the distance between the anode and the cathode is changed, forming a gradient distance electrolysis with a large distance at the top and a small distance inside the molten salt, and a molten salt electrolysis method in which the anode in a specific area participates in the electrochemical reaction, so that the anode in a specific area (the area with slower consumption) is close to the cathode, accelerating its consumption and improving the utilization rate of the anode, which can increase the life of the anode, reduce the residual electrode rate, improve the current efficiency, and reduce energy consumption.

[0024] (3) Through the automatic adjustment of the anode, a gradient electrode distance electrolysis is formed, which reduces the degree of reaction at the three-phase interface and reduces the consumption at the interface. At the same time, by moving the anode and adjusting the position of the three-phase interface, it is possible to avoid the problem that the current static anode three-phase interface position is consumed quickly, resulting in the need to replace the anode in advance.

[0025] (4) Through automatic adjustment of the anode, as the anode is consumed, the anode distance is changed in time to reduce the cell voltage and save energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the structure of the anode automatic control rare earth electrolytic cell of the present invention.

[0027] Figure 2 It is a schematic diagram of the structure of the actuator of the present invention.

[0028] In the figure, 1 is the anode, 2 is the cathode, 3 is the conductive anode fixture, 4 is the molten salt, 5 is the omnidirectional movable base, 6 is the Z-axis lifting rod, 7 is the first motor, 8 is the motor shaft of the first motor, 9 is the second motor, and 10 is the motor shaft of the second motor. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with embodiments.

[0030] Example 1

[0031] An anode automatic control electrolytic cell, the structural schematic diagram of which is shown in Figure 1 The anode automatic control electrolytic cell is provided with an electrolytic cell body, in which a molten salt 4 is contained, a cylindrical cathode 2 is provided at the center of the electrolytic cell body, a rectangular anode 1 is provided around the electrolytic cell body, the rectangular anode 1 is connected to a conductive anode fixture 3, one end of the conductive anode fixture 3 is used to fix the rectangular anode, and the other end of the conductive anode fixture 3 is connected to an actuator;

[0032] The actuator described above has a structural diagram as shown in Figure 2, including an omnidirectional movable base 5, a Z-direction lifting rod 6 is connected above the omnidirectional movable base 5, a first motor 7 is fixedly connected above the Z-direction lifting rod 6, a motor shaft 8 of the first motor is parallel to the X-axis, an output end of the motor shaft 8 of the first motor is fixedly connected to the second motor 9, a motor shaft 10 of the second motor is parallel to the Y-axis, wherein the motor shaft 10 of the second motor is connected to the conductive anode fixture 3; in the actuator, the omnidirectional movable base is used to realize the actuator driving the conductive anode fixture to move in the X-axis and Y-axis, and to rotate around the Z-axis; the Z-direction lifting rod is used to realize the actuator driving the conductive anode fixture to move in the Z-axis, the motor shaft of the first motor is used to realize the actuator driving the conductive anode fixture to rotate around the X-axis, and the motor shafts of the second motor are respectively used to realize the actuator driving the conductive anode fixture to rotate around the Y-axis.

[0033] At the beginning of electrolysis, the central axis line of the rectangular anode coincides with the Z axis. As the electrolysis proceeds, the anode fixture automatic control system is used to adjust the rotation of the motor, and the anode moves toward the cathode along the X axis at a speed equal to the anode consumption speed in the X axis direction, moves toward the inside of the molten salt along the Z axis at a speed equal to the anode consumption speed in the Z axis direction, and moves back and forth on both sides along the Y axis direction, with the maximum moving distance being 30% of the length of the anode in the Y direction, and the moving speed being 1 hour as a cycle; the anode top surface is fixed as a fixed point and the Z axis is used as the axis to reciprocate at 10° / h within -30° to 30°, the anode top surface is fixed as a fixed point and the anode is periodically swung at a uniform speed of 15° / h within -30° to 30° in the YZ plane, and the anode bottom end is rotated 5° toward the cathode in the XZ plane with the center point of the anode top surface as a fixed point, and the rotation axis is the Y axis, so that the molten salt surface pole distance is large and the molten salt internal pole distance is small; the current efficiency obtained is 90%, and the anode utilization rate is increased by 30% compared with the electrolysis of equal pole distance with the anode fixed.

[0034] Example 2

[0035] Same as Example 1

[0036] The difference is that the motor shaft 10 of the second motor of the actuator rotates, and the lower end of the anode is rotated 15° toward the cathode in the XZ plane with the center point of the top surface of the anode as a fixed point to carry out electrolysis. The current efficiency obtained is 88%. Compared with the equipolar distance electrolysis with the anode fixed, the anode utilization rate is increased by 27%.

[0037] Example 3

[0038] Same as Example 1

[0039] The difference is that the motor shaft 10 of the second motor of the actuator rotates, and the lower end of the anode is rotated 28° toward the cathode in the XZ plane with the center point of the top surface of the anode as a fixed point to carry out electrolysis. The current efficiency obtained is 84%. Compared with the equipolar distance electrolysis with the anode fixed, the anode utilization rate is increased by 29%.

[0040] Example 4

[0041] Same as Example 1

[0042] The difference is that the actuator does not include the first motor 7 and the motor shaft 8 of the first motor, but the second motor 9 is fixedly connected above the Z-axis lifting rod 6; in addition, the motor shaft 10 of the second motor of the actuator rotates so that the anode is fixed at the center point of the top surface of the anode in the XZ plane so that the lower end of the anode is rotated 45° toward the cathode to carry out electrolysis, and the current efficiency obtained is 82%. Compared with the equipolar electrolysis with fixed anodes, the anode utilization rate is increased by 20%.

[0043] Example 5

[0044] Same as Example 1

[0045] The difference is that the actuator does not include the Z-axis lifting rod 6, the first motor 7 and the motor shaft 8 of the first motor, but the second motor 9 is fixedly connected above the omnidirectional movable base 5; in addition, the motor shaft 10 of the second motor of the actuator rotates so that the anode is fixed at the center point of the top surface of the anode in the XZ plane so that the lower end of the anode is rotated 10° toward the cathode to carry out electrolysis, and the current efficiency obtained is 92%. Compared with the equipolar electrolysis with fixed anodes, the anode utilization rate is increased by 15%.

[0046] Example 6

[0047] Same as Example 1

[0048] The difference is that the omnidirectional movable base 5 rotates around the Z axis, so that the anode reciprocates at 30° / h within -30° to 30° with the center point of the top surface of the anode as a fixed point and the Z axis as the axis; in addition, the motor shaft 10 of the second motor of the actuator rotates, so that the anode is fixed with the center point of the top surface of the anode as a fixed point in the XZ plane so that the lower end of the anode is rotated 10° toward the cathode to carry out electrolysis, and the current efficiency obtained is 86%. Compared with the equipolar electrolysis with a fixed anode, the anode utilization rate is increased by 29%.

[0049] Example 7

[0050] Same as Example 1

[0051] The difference is that the omnidirectional movable base 5 reciprocates along the Y-axis, so that the anode reciprocates on both sides of the Y-axis, the maximum moving distance is 30% of the length of the anode in the Y direction, and the moving speed is 5 hours as a cycle; in addition, the motor shaft 10 of the second motor of the actuator rotates, so that the anode is fixed with the center point of the top surface of the anode as the fixed point in the XZ plane so that the lower end of the anode is rotated 13° toward the cathode to carry out electrolysis, and the current efficiency obtained is 82%. Compared with the equipolar electrolysis with a fixed anode, the anode utilization rate is increased by 29%.

[0052] Example 8

[0053] Same as Example 1

[0054] The difference is that the omnidirectional movable base 5 reciprocates along the Y-axis and rotates around the Z-axis, so that the anode reciprocates on both sides of the Y-axis, the maximum moving distance is 30% of the length of the anode in the Y-direction, and the moving speed is 2 hours as a cycle, with the center point of the top surface of the anode as the fixed point and the Z-axis as the axis, reciprocating at 20° / h within -30° to 30°; in addition, the motor shaft 10 of the second motor of the actuator rotates, so that the anode is fixed at the center point of the top surface of the anode in the XZ plane so that the lower end of the anode rotates 7° toward the cathode for electrolysis, and the current efficiency obtained is 95%. Compared with the equipolar electrolysis with the anode fixed, the anode utilization rate is increased by 25%.

[0055] Comparative Example 1

[0056] The same as Example 1, except that: during the anodic electrolysis process, the anode is fixed and maintained at the same distance from the cathode, so the current efficiency is 60-75%.

Claims

1. A method for executing anode action in a rare earth electrolytic cell, characterized in that: In the rare earth electrolysis process, according to the anode consumption, the movement direction of the anode is adjusted with full freedom to form a gradient distance with large distance on the molten salt surface and small distance inside the molten salt for electrolysis; wherein the movement direction of the anode is adjusted with full freedom, with the symmetry axis vertical to the top surface of the anode as the Z axis, the line connecting the anode and the cathode on the horizontal plane as the X axis, and the direction perpendicular to the X axis on the horizontal plane as the Y axis; The anode movement is one of the following: moving the anode closer to the cathode along the X-axis, moving the anode along the Z-axis toward the inside of the molten salt, reciprocating the anode along the Y-axis, rotating with the Z-axis as the axis with the center point of the top surface of the anode as the fixed point, swinging in the YZ plane with the center point of the top surface of the anode as the fixed point, or a combination of several movement modes, and then swinging in the plane formed by the XZ plane with the center point of the top surface of the anode as the fixed point; The anode is moved closer to the cathode along the X-axis, so that the anode as a whole moves closer to the center of the electrolytic cell. The moving speed is the same as the anode consumption speed during the electrolysis process, ensuring that the pole distance remains unchanged and does not change with the consumption of the anode. The anode moves along the Z axis toward the inside of the molten salt, and the moving speed matches the anode consumption speed in order to move the anode toward the inside of the molten salt; The anode moves back and forth along the Y axis in a direction perpendicular to the line connecting the anode and the cathode, and the movement amplitude is less than 30% of the length of the top surface of the anode in the Y axis direction; The rotation with the center point of the top surface of the anode as the fixed point and the Z axis as the axis refers to periodic uniform rotation, and the rotation angle is -30° to 30°; wherein 0° is when the anode coincides with the initial unrotated position; The swinging in the YZ plane with the center point of the anode top surface as a fixed point refers to periodic and uniform swinging on the plane formed by YZ, with the axis of the swing being the X axis and the swing angle being -30° to 30°; wherein 0° coincides with the initial non-swinging position of the anode; The swinging in the plane formed by XZ with the center point of the top surface of the anode as the fixed point means that the Z axis can be rotated in the X axis direction, the axis of rotation is the Y axis, and after rotating to a certain angle, it will not move in this direction during the electrolysis process, wherein the rotation angle is between 5° and 45°, and finally the molten salt surface pole distance is large and the molten salt internal pole distance is small; By adopting the anode action execution method in the rare earth electrolytic cell, the current efficiency of the rare earth electrolytic cell automatically controlled by the anode is greater than 80%, and the utilization rate of the anode is increased by 15%.

2. An anode automatic control rare earth electrolytic cell, comprising an electrolytic cell body, a cathode and an anode, characterized in that: Also included are a conductive anode clamp for clamping the anode and an actuator for controlling the movement of the anode; The actuator can realize the anode action mode, including one of the following actions: moving the anode closer to the cathode along the X-axis, moving the anode along the Z-axis toward the inside of the molten salt, reciprocating the anode along the Y-axis, rotating with the Z-axis as the axis with the center point of the top surface of the anode as the fixed point, swinging in the YZ plane with the center point of the top surface of the anode as the fixed point, and swinging in the plane formed by the XZ plane with the center point of the top surface of the anode as the fixed point, or a combination of several action modes; The conductive anode fixture is connected to the anode and fixes the anode, and the conductive anode fixture is connected to the actuator; When the actuator is an actuator for realizing full-degree-of-freedom adjustment of the anode, the actuator includes an omnidirectional movable base, a Z-direction lifting rod is connected above the omnidirectional movable base, a first motor is fixedly connected above the Z-direction lifting rod, a motor shaft of the first motor is parallel to the X-axis or the Y-axis, an output end of the motor shaft of the first motor is fixedly connected to the second motor, a motor shaft of the second motor is parallel to the Y-axis or the X-axis, and the motor shaft of the first motor is perpendicular to the motor shaft of the second motor; in the actuator, the omnidirectional movable base is used to realize that the actuator drives the conductive anode fixture to move in the X-axis and Y-axis, and rotate around the Z-axis; the Z-direction lifting rod is used to realize that the actuator drives the conductive anode fixture to move in the Z-axis, and the motor shaft of the first motor and the motor shaft of the second motor are respectively used to realize that the actuator drives the conductive anode fixture to rotate around the X-axis and around the Y-axis.

3. The anode automatic control rare earth electrolytic cell according to claim 2, characterized in that: The motor shaft of the second motor is connected to the conductive anode fixture, and the anode action is executed through independent or combined execution of the actuator.

4. The anode automatic control rare earth electrolytic cell according to claim 2, characterized in that: When the actuator is used to realize a certain action mode of the anode, the structural components that realize other action modes are removed.

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