Electrolytic crude magnesium refining device and process

Abstract

The application provides an electrolytic crude magnesium refining device and process. The device comprises an outer cylinder and an inner cylinder. The inner cylinder is arranged in the inner part of the outer cylinder. The inner part of the outer cylinder and the inner part of the inner cylinder are isolated. The inner part of the outer cylinder forms a crude magnesium refining area, and the inner part of the inner cylinder forms a refined magnesium storage area. A communication pipe is arranged on the inner cylinder. The two ends of the communication pipe communicate with the inner cylinder and the outer cylinder. Pressure adjusting devices are connected to the outer cylinder and the inner cylinder. The refined magnesium is transferred from the crude magnesium refining area to the refined magnesium storage area through the communication pipe by controlling the pressure difference between the inner part of the outer cylinder and the inner part of the inner cylinder. The refining crucible is divided into two cavities by the arrangement of the outer cylinder and the inner cylinder. The upper layer after refining in the inner part of the outer cylinder enters the refined magnesium storage area through the communication pipe. Meanwhile, the electrolytic slag at the bottom of the outer cylinder cannot enter the inner part of the inner cylinder. The crude magnesium and the refined magnesium are completely separated. The electrolyte impurities in the electrolytic refined magnesium are effectively separated and removed. The impurities in the magnesium cannot enter the downstream titanium sponge production process to pollute the titanium sponge. The crude magnesium and the refined magnesium are effectively prevented from mixing to pollute the refined magnesium.

Description

Technical Field

[0001] This invention relates to the field of sponge titanium production, and more specifically, to an electrolytic crude magnesium refining apparatus and process. Background Technology

[0002] In the whole process of sponge titanium production, the electrolysis section provides raw material liquid magnesium for sponge titanium production. Usually, the liquid magnesium obtained from the electrolysis cell needs to go through a refining process to obtain refined magnesium, which is then sent to the reduction distillation section for the production of sponge titanium. Therefore, the refining process has an important impact on the quality of sponge titanium production.

[0003] Traditional Pidgeon process for refining crude magnesium typically uses flux No. 2 as a refining agent. The flux No. 2 is added to the crude magnesium to create slag and remove impurities from the liquid magnesium. This method effectively removes non-metallic oxides from the crude magnesium. Due to differences in production processes, the crude magnesium produced by electrolysis is relatively pure. The internal impurities are mainly electrolytes brought in from the electrolytic cell during the crude magnesium transport process. The electrolytes and magnesium have a large wetting angle and different densities, which can generally be separated by settling. Therefore, the traditional practice is to let the electrolytically refined crude magnesium settle for a period of time to allow the electrolytes to settle and separate, thus obtaining refined magnesium. Existing technology, patent publication number CN201241185Y, discloses an extraction device for electrolytically refined magnesium, including a magnesium extraction frame, a magnesium extraction tube, and springs. The magnesium extraction tube passes through a hole in the magnesium extraction frame and is mounted on the frame, with a spring located on its upper part. The device consists of two sets, one long and one short. The end of the magnesium extraction tube in one set should be able to insert 20-35 cm above the bottom of the crucible, while the other set should be 40-50 cm shorter. The magnesium extraction frame is placed on the large cover, and the magnesium extraction tube is inserted through a hole in the cover into the refined magnesium crucible. Magnesium is extracted using the depth difference created by the different lengths of the long and short extraction tubes within the crucible. However, in actual operation, when extracting magnesium from the refining furnace using the above method or by siphoning, some electrolyte will inevitably be carried away. If this electrolyte is introduced into the distillation process, it will contaminate the sponge titanium. Summary of the Invention

[0004] In view of this, the present invention aims to provide an electrolytic crude magnesium refining apparatus and process to solve the problem that electrolyte impurities cannot be effectively removed during magnesium refining in the prior art.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0006] An electrolytic crude magnesium refining apparatus includes an outer cylinder and an inner cylinder. The inner cylinder is disposed inside the outer cylinder, and the interior of the outer cylinder and the interior of the inner cylinder are isolated. The interior of the outer cylinder forms a crude magnesium refining zone, and the interior of the inner cylinder forms a refined magnesium storage zone. A connecting pipe is provided on the inner cylinder, and the two ends of the connecting pipe connect the inner cylinder and the outer cylinder. Both the outer cylinder and the inner cylinder are connected to pressure regulating devices. By controlling the pressure difference between the interior of the outer cylinder and the inner cylinder, refined magnesium is transferred from the crude magnesium refining zone to the refined magnesium storage zone through the connecting pipe.

[0007] Furthermore, the length of the connecting pipe is set according to the diameter of the outer cylinder, the diameter of the inner cylinder, and the height of the inner cylinder, and the lower end of the connecting pipe is higher than the plane where the bottom of the inner cylinder is located.

[0008] Furthermore, an outer cylinder cover is provided at the top of the outer cylinder, and the outer cylinder cover is connected to the outer cylinder through a flange to form a sealed cavity. The inner cylinder is fixedly connected to the outer cylinder cover near the top.

[0009] Furthermore, a slag discharge pipe is also provided inside the outer cylinder. One end of the slag discharge pipe extends into the outer cylinder near the bottom, and the top end of the slag discharge pipe extends outward through the outer cylinder cover. The slag discharge pipe is used to discharge the electrolyte refining slag inside the outer cylinder to the outside of the outer cylinder.

[0010] Furthermore, a magnesium inlet is provided on the outer cylinder, which is connected to an external feeding device.

[0011] Furthermore, the magnesium inlet is located at or near the top of the outer cylinder, or the magnesium inlet is located on the outer cylinder cover.

[0012] Furthermore, an inner cylinder cover is provided at the top of the inner cylinder, and the inner cylinder cover and the inner cylinder are connected by a flange to form a sealed cavity, in which a fine magnesium storage area is formed.

[0013] Furthermore, a magnesium outlet pipe is provided inside the inner cylinder, with one end of the magnesium outlet pipe extending into the inner cylinder near the bottom, and the top end of the magnesium outlet pipe extending outward through the inner cylinder cover.

[0014] Furthermore, a pressure gauge, an argon purging port, a pressure relief port, and a level gauge are also connected to the outer cylinder cover. The pressure gauge is used to detect the internal pressure of the cavity, the argon purging port and the pressure relief port are used to regulate the pressure and control the material flow, and the level gauge is used to detect the internal liquid level.

[0015] Compared with existing technologies, the electrolytic crude magnesium refining apparatus of the present invention has the following advantages:

[0016] The outer and inner cylinders divide the refining crucible into two chambers, allowing the upper layer of refined magnesium to enter the magnesium storage area through a connecting pipe inside the outer cylinder. At the same time, it prevents the electrolytic slag at the bottom of the outer cylinder from entering the inner cylinder, thus completely separating crude magnesium from refined magnesium. This effectively separates and removes electrolyte impurities from the electrolytic refined magnesium, preventing impurities in magnesium from entering the downstream distillation process and contaminating the sponge titanium. It also effectively avoids the mixing of crude magnesium and refined magnesium, which can contaminate the refined magnesium.

[0017] The present invention also provides an electrolytic crude magnesium refining process, using the electrolytic crude magnesium refining apparatus described above, the electrolytic crude magnesium refining process comprising the following steps:

[0018] Add crude magnesium to the crude magnesium refining zone. The amount of crude magnesium added should not exceed the lower edge of the upper end of the connecting pipe. After adding the crude magnesium, refine it. After the crude magnesium in the outer cylinder is converted into refined magnesium, let it stand.

[0019] The pressure inside the outer cylinder is controlled to be greater than the pressure inside the inner cylinder, so that the produced refined magnesium is transferred into the inner cylinder through the connecting pipe. When the liquid magnesium level in the outer cylinder drops below the level at the lower end of the connecting pipe, the transfer automatically ends.

[0020] By controlling the pressure inside both the outer and inner cylinders to be higher than atmospheric pressure, the refined magnesium inside the inner cylinder is discharged into the material lifting bag.

[0021] The electrolytic crude magnesium refining process and the electrolytic crude magnesium refining device described above have the same advantages over the prior art, and will not be repeated here. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the electrolytic crude magnesium refining apparatus according to an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the electrolytic crude magnesium refining process described in an embodiment of the present invention.

[0024] Explanation of reference numerals in the attached figures:

[0025] 1-Outer cylinder, 2-Inner cylinder, 3-Outer cylinder cover, 4-Inner cylinder cover, 5-Slag discharge pipe, 6-Magnesium outlet pipe, 7-Magnesium inlet, 8-Connecting pipe, 10-Crude magnesium refining area, 11-Electrolytic slag area, 20-Refined magnesium storage area Detailed Implementation

[0026] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The term "connection" can refer to a direct connection or an indirect connection, and the term "on" means directly supported by an element, or indirectly supported by an element through another element integrated into or supported by that element.

[0027] like Figure 1As shown, this embodiment provides an electrolytic crude magnesium refining apparatus, including an outer cylinder 1 and an inner cylinder 2. The inner cylinder 2 is disposed inside the outer cylinder 1, and the interior of the outer cylinder 1 and the interior of the inner cylinder 2 are isolated. A crude magnesium refining zone 10 is formed inside the outer cylinder 1, and a refined magnesium storage zone 20 is formed inside the inner cylinder 2. A connecting pipe 8 is provided on the inner cylinder 2, and the two ends of the connecting pipe 8 are connected to the inner cylinder 2 and the outer cylinder 1. Pressure regulating devices are connected to both the outer cylinder 1 and the inner cylinder 2. By controlling the pressure difference inside the outer cylinder 1 and the inner cylinder 2, refined magnesium is transferred from the crude magnesium refining zone to the refined magnesium storage zone through the connecting pipe 8. The outer cylinder 1 and inner cylinder 2 divide the refining crucible into two cavities, allowing the upper layer of magnesium liquid after refining inside the outer cylinder 1 to enter the refined magnesium storage area through the connecting pipe. At the same time, it can prevent the electrolytic slag in the electrolytic slag area 11 at the bottom of the outer cylinder 1 from entering the inner cylinder 2, thus completely separating the crude magnesium from the refined magnesium. This effectively separates and removes electrolyte impurities from the electrolytic refined magnesium, preventing impurities in the magnesium from entering the downstream distillation process and contaminating the sponge titanium. It also effectively prevents the crude magnesium from mixing with the refined magnesium and contaminating the refined magnesium.

[0028] Specifically, a liquid magnesium inlet is located near the upper part of the side wall of the inner cylinder 2. A connecting pipe 8 is connected to the liquid magnesium inlet, and the liquid magnesium generated in the outer cylinder 1 flows into the inner cylinder 2 through the connecting pipe 8 and the liquid magnesium inlet. The length of the connecting pipe 8 is set according to the diameter of the outer and inner cylinders and the height of the inner cylinder 2. The lower end of the connecting pipe 8 is higher than the plane of the bottom of the inner cylinder 2 to prevent electrolytic slag inside the outer cylinder 1 from entering the inner cylinder 2. Preferably, viewed from the bottom of the inner cylinder 2 upwards, the lower end of the connecting pipe 8 is set between one-third and one-half of the height of the inner cylinder 2. The upper end of the connecting pipe 8, i.e., the liquid magnesium inlet on the inner cylinder 2, is set between 60% and 90% of the height of the inner cylinder 2.

[0029] Specifically, assuming the diameter of outer cylinder 1 is D, the diameter of inner cylinder 2 is d, the height of inner cylinder 2 is h, and the length of the connecting pipe is L, the specific relationships are as follows:

[0030]

[0031] This invention avoids the electrolytic slag inside the outer cylinder 1 from entering the inner cylinder 2 if the lower end of the connecting pipe 8 is too low, while also preventing the upper layer of refined magnesium liquid from not easily entering the inner cylinder 2 if the connecting pipe 8 is too high. Furthermore, by setting the diameters of the outer cylinder 1 and the inner cylinder 2, as well as the height of the inner cylinder, and combining this with the pressure regulating device on the inner and outer cylinders, a natural pressure difference is created between the inner and outer cylinders. This allows the upper layer of magnesium liquid in the outer cylinder 1 to naturally enter the inner cylinder 2, eliminating the need for additional suction devices or valves on the connecting pipe to achieve the opening and closing of the connecting pipe.

[0032] The inner cylinder 2 is located near the upper part of the outer cylinder 1. A large space is provided between the lower part of the inner cylinder 2 and the bottom of the outer cylinder 1 to fully accommodate the electrolytic slag and prevent the electrolytic slag from entering the interior of the inner cylinder 2.

[0033] An outer cylinder cover 3 is installed at the top of the outer cylinder 1. The outer cylinder cover 3 is connected to the outer cylinder 1 through a flange to form a sealed cavity. The inner cylinder 2 is fixedly connected to the outer cylinder cover 3 near the top to provide support and fixation for the inner cylinder. A slag discharge pipe 5 is also installed inside the outer cylinder 1. One end of the slag discharge pipe 5 extends into the outer cylinder 1 near the bottom, and the top end of the slag discharge pipe 5 extends outward through the outer cylinder cover 3. The slag discharge pipe 5 is used to discharge the electrolyte refining slag in the electrolytic slag zone 11 inside the outer cylinder 1 to the outside of the outer cylinder 1.

[0034] Furthermore, a magnesium inlet 7 is provided on the outer cylinder 1. The magnesium inlet 7 is connected to an external feeding device, and crude magnesium can be added to the interior of the outer cylinder 1 through the magnesium inlet 7. Preferably, the magnesium inlet 7 is located at or near the top of the outer cylinder 1. For example, the magnesium inlet 7 can be located on the outer cylinder cover 3 and on the side away from the slag discharge pipe 5.

[0035] An inner cylinder cover 4 is installed at the top of the inner cylinder 2. The inner cylinder cover 4 and the inner cylinder 2 are connected by a flange to form a sealed cavity, which forms a refined magnesium storage area. A magnesium outlet pipe 6 is installed inside the inner cylinder 2. One end of the magnesium outlet pipe 6 extends into the inner cylinder 2 near the bottom, and the top end of the magnesium outlet pipe 6 extends outward through the inner cylinder cover 4. When the refined magnesium liquid level in the refined magnesium storage area reaches a certain height, the magnesium outlet pipe 6 is used to discharge and collect the refined magnesium liquid.

[0036] Furthermore, in this embodiment, a pressure gauge, an argon purging port, a pressure relief port, and a level gauge are also provided on the outer cylinder cover 3 and the inner cylinder cover 4. The pressure gauge is used to detect the internal pressure of the cavity, the argon purging port and the pressure relief port are used to adjust the pressure and control the material flow, and the level gauge is used to detect the internal liquid level.

[0037] Furthermore, in this embodiment, the top of the inner cylinder cover 4 is higher than the top of the outer cylinder cover 3, so that the top of the magnesium outlet pipe 6 is higher than the top of the slag discharge pipe 5, thus avoiding interference between the magnesium outlet pipe 6 and the slag discharge pipe 5.

[0038] As part of the embodiments of the present invention, an electrolytic crude magnesium refining process is also provided, such as... Figure 2 As shown, using the electrolytic crude magnesium refining apparatus described above, the electrolytic crude magnesium refining process includes the following steps:

[0039] In the first stage, a certain amount of crude magnesium is added to the crude magnesium refining zone. The amount of crude magnesium added should be detected by a level gauge and should not exceed the lower edge of the upper port of the connecting pipe 8. Figure 2 As shown in the schematic diagram on the left. After adding crude magnesium, refining is carried out. After the crude magnesium in the refining zone is transformed into refined magnesium, it is left to stand. The outer cylinder 1 is layered, and the lower layer forms the electrolytic slag zone.

[0040] In the second stage, by controlling the pressure in the crude magnesium refining zone to be higher than the pressure in the refined magnesium storage zone, that is, by controlling the pressure inside the outer cylinder 1 to be higher than the pressure inside the inner cylinder 2, the already produced refined magnesium is transferred to the refined magnesium storage zone through the connecting pipe. Figure 2 As shown in the central diagram. When the liquid magnesium level in the crude magnesium refining zone drops to the lower end of the connecting pipe, the transfer automatically ends, effectively preventing further material from being transferred in. For example... Figure 2 As shown in the diagram on the right.

[0041] In the third stage, by controlling the pressure of the two chambers to be higher than atmospheric pressure, the refined magnesium in the magnesium storage area is discharged into the material lifting bag. At this point, the entire refining process ends, and the cycle begins again from the first stage.

[0042] The electrolytic crude magnesium refining process provided in this embodiment can effectively prevent electrolyte impurities in the electrolytic crude magnesium from being introduced into the refined magnesium, and can completely and effectively separate crude magnesium from refined magnesium during the refining process, thereby preventing impurities in refined magnesium from being introduced into the sponge titanium.

[0043] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. An apparatus for refining crude magnesium by electrolysis, characterized by comprising: The device comprises an outer cylinder (1) and an inner cylinder (2), the inner cylinder (2) is arranged inside the outer cylinder (1), the inner part of the outer cylinder (1) and the inner part of the inner cylinder (2) are isolated, the inner part of the outer cylinder (1) forms a crude magnesium refining area, the inner part of the inner cylinder (2) forms a refined magnesium storage area, a communication pipe (8) is arranged on the inner cylinder (2), the two ends of the communication pipe (8) communicate with the inner cylinder (2) and the outer cylinder (1), the outer cylinder (1) and the inner cylinder (2) are both connected with pressure adjusting devices, refined magnesium is transferred from the crude magnesium refining area to the refined magnesium storage area through the communication pipe (8) by controlling the pressure difference between the inner part of the outer cylinder (1) and the inner part of the inner cylinder (2), the length of the communication pipe (8) is set according to the diameter of the outer cylinder (1), the diameter of the inner cylinder (2) and the height of the inner cylinder (2), the lower end of the communication pipe (8) is higher than the plane where the bottom of the inner cylinder (2) is located, the diameter of the outer cylinder (1) is D, the diameter of the inner cylinder (2) is d, the height of the inner cylinder (2) is h, and the length of the communication pipe (8) is L, and the specific relationship is as follows: 。 2. The electrolytic crude magnesium refining apparatus according to claim 1, characterized by An outer cylinder cover (3) is arranged at the top of the outer cylinder (1), the outer cylinder cover (3) is connected with the outer cylinder (1) through a flange to form a sealed cavity, and the inner cylinder (2) is fixedly connected with the outer cylinder cover (3) at a position close to the top.

3. The electrolytic crude magnesium refining apparatus according to claim 2, characterized by A slag discharge pipe (5) is further arranged in the inner part of the outer cylinder (1), one end of the slag discharge pipe (5) extends into the inner part of the outer cylinder (1) close to the bottom, and the top end of the slag discharge pipe (5) extends outwards through the outer cylinder cover (3), and the slag discharge pipe (5) is used for discharging electrolyte refining slag in the inner part of the outer cylinder (1) to the outside of the outer cylinder (1).

4. The electrolytic crude magnesium refining apparatus according to claim 2 or 3, characterized by A magnesium adding port (7) is further arranged on the outer cylinder (1), and the magnesium adding port (7) communicates with an external feeding device.

5. The electrolytic crude magnesium refining apparatus according to claim 4, characterized by The magnesium adding port (7) is arranged at the top or a position close to the top of the outer cylinder (1), or the magnesium adding port (7) is arranged on the outer cylinder cover (3).

6. The electrolytic crude magnesium refining apparatus according to claim 1, characterized by An inner cylinder cover (4) is arranged at the top of the inner cylinder (2), the inner cylinder cover (4) is connected with the inner cylinder (2) through a flange to form a sealed cavity, and the cavity forms a refined magnesium storage area.

7. The electrolytic crude magnesium refining apparatus according to claim 6, characterized by An magnesium outlet pipe (6) is arranged in the inner part of the inner cylinder (2), one end of the magnesium outlet pipe (6) extends into the inner part of the inner cylinder (2) close to the bottom, and the top end of the magnesium outlet pipe (6) extends outwards through the inner cylinder cover (4).

8. The electrolytic crude magnesium refining apparatus according to claim 2, characterized by A pressure gauge, an argon flushing port, a pressure relief port and a liquid level gauge are further connected with the outer cylinder cover (3), the pressure gauge is used for detecting the pressure in the cavity, the argon flushing port and the pressure relief port are used for adjusting the pressure to control the flow of materials, and the liquid level gauge is used for detecting the internal liquid level.

9. An electrolytic crude magnesium refining process characterized by, The electrolytic crude magnesium refining device is used for the electrolytic crude magnesium refining process, and the process comprises the following steps: Crude magnesium is added to the crude magnesium refining area, the added amount of the crude magnesium does not exceed the lower edge of the upper port of the communication pipe, after the addition of the crude magnesium, refining is performed, and after the crude magnesium in the outer cylinder becomes refined magnesium, the device is kept still, The pressure inside the outer cylinder is greater than the pressure inside the inner cylinder, so that the produced refined magnesium is transferred into the inner cylinder through the communication pipe, and the transferring is automatically ended when the liquid magnesium level in the outer cylinder is lowered to a level below the lower end of the communication pipe; The refined magnesium in the inner cylinder is discharged into the material ladle by controlling the pressure in the whole outer cylinder and the inner cylinder to be higher than the atmospheric pressure.

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