阅读说明：本技术 一种间歇式连续提取皮江法炼镁中的结晶镁的方法及装置 (Method and device for intermittently and continuously extracting crystallized magnesium in Pidgeon magnesium smelting ) 是由 孙院军 柏小丹 孙军 丁向东 李金阳 于 2021-08-25 设计创作，主要内容包括：一种间歇式连续提取皮江法炼镁中的结晶镁的方法及装置,将扇形叶片插入冷凝管中,扇叶面正对结晶管的轴向,轴向相邻扇面之间既有上下交替还有左右交替,使镁蒸气呈现三维波浪式或“S”型路径行进,延长结晶路径,增加结晶面积这样显著增加了结晶镁的沉积面积,增加了沉积机会,提高了结晶效率。随着时间的持续,大量的结晶镁沉积在扇叶前后面上。通过金属杆的热传导和循环水量控制,交替将冷却扇叶温度保持在650℃(镁金属的熔点)以上。使扇叶上的液体镁或者结晶镁处于熔化状态,在重力和金属杆束的毛细管作用下,沿着扇叶上面预先设置的沟槽向下流动至镁精炼池。如此周而复始,完成这个冷却段内扇叶上结晶镁的连续化提出。(A method and a device for intermittently and continuously extracting crystalline magnesium in magnesium smelting by Pidgeon process are disclosed, wherein fan-shaped blades are inserted into a condensing tube, the surfaces of the fan blades are opposite to the axial direction of the crystallizing tube, and the adjacent fan surfaces in the axial direction are not only vertically alternated but also horizontally alternated, so that magnesium vapor is advanced in a three-dimensional wave type or S-shaped path, the crystallizing path is prolonged, the crystallizing area is increased, the depositing area of the crystalline magnesium is obviously increased, the depositing chance is increased, and the crystallizing efficiency is improved. Over time, a large amount of crystalline magnesium deposits on the front and back of the fan blade. The temperature of the cooling fan blades is alternately kept above 650 ℃ (the melting point of magnesium metal) by controlling the heat conduction and the circulating water quantity of the metal rod. Liquid magnesium or crystallized magnesium on the fan blades is in a molten state and flows downwards to a magnesium refining pool along the grooves preset on the fan blades under the action of gravity and capillary action of the metal rod bundles. And repeating the steps to complete the continuous extraction of the crystallized magnesium on the fan blades in the cooling section.)

1. The device for intermittently and continuously extracting the crystallized magnesium in the Pidgeon magnesium smelting is characterized in that: the magnesium smelting reduction furnace comprises a reduction tank (1) arranged in a reduction furnace (3) and a magnesium crystallizer (2) communicated with the reduction tank (1), wherein the magnesium crystallizer (2) comprises a condensation coating sleeve (25) and a magnesium smelting pool (23) which are arranged in a closed space from top to bottom, one end of the condensation coating sleeve (25) is provided with a magnesium steam inlet end (26) which is coaxially connected with the reduction tank (1), the other end of the condensation coating sleeve is provided with a tail gas outlet (27), a metal rod bundle (22) with fan blades (21) is arranged between the condensation coating sleeve (25) and the magnesium smelting pool (23), the lower end of the metal rod bundle (22) is inserted into the magnesium smelting pool (23), and the fan blades (21) at the upper end of the metal rod bundle (22) are positioned in the condensation coating sleeve (25).

2. The device for intermittently and continuously extracting the crystallized magnesium in the pidgeon magnesium smelting process according to claim 1, which is characterized in that: the metal rod bundle (22) is formed by inserting at least four fan blades (21) which are staggered up and down, left and right and metal rods at the lower parts of the fan blades into a metal pipe in a binding mode, penetrating through a metal pipe bundle penetrating area (2111) of a condensation coating sleeve (25) and inserting into a magnesium molten pool (23).

3. The device for intermittently and continuously extracting the crystallized magnesium in the pidgeon magnesium smelting process according to claim 1, which is characterized in that: the metal rod bundle (22) is formed by tightly winding metal wires made of the same material on the metal rods to form a metal rod bundle with fan blades (21), and the metal rod bundle penetrates through a metal tube bundle penetrating area (2111) of the condensation coating sleeve (25) to be inserted into a magnesium molten pool (23).

4. The device for intermittently and continuously extracting the crystallized magnesium in the pidgeon magnesium smelting process according to claim 1, which is characterized in that: the fan blade surfaces of the fan-shaped pieces (21) are opposite to the axial direction in the condensation casing pipe (25), the fan surfaces of the axially adjacent fan-shaped pieces (21) are alternated up and down, left and right, the alternating distance is 20mm, and the distance between the fan surfaces of the fan-shaped pieces (21) and the condensation casing pipe (25) is 20 mm.

5. The device for intermittently and continuously extracting the crystallized magnesium in the pidgeon magnesium smelting process according to claim 1, which is characterized in that: the groove (211) of the fan blade (21) is a wave-shaped groove along the direction of the metal rod bundle.

6. The device for intermittently and continuously extracting the crystallized magnesium in the pidgeon magnesium smelting process according to claim 1, which is characterized in that: the cooling jacket pipe (25) is divided into more than four cooling areas with inlet and outlet circulating cooling water along the axial direction.

7. A method for intermittently and continuously extracting crystalline magnesium in Pidgeon magnesium smelting according to any one of the claims 1 to 6, which is characterized in that:

1) adding a reducing material of magnesium into a reduction tank (1);

2) adding raw material magnesium into a magnesium molten pool (23) to ensure that the bottom of the magnesium molten pool is submerged in the metal rod bundle (22);

3) under the vacuum condition, before the equipment is started, synchronously vacuumizing the magnesium crystallizer (2) and the reduction tank (1) at the vacuum degree of 3-15 Pa;

or synchronously finishing the replacement of argon or helium by the magnesium crystallizer (2) and the reduction tank (1) in the state of argon or helium;

4) starting the reduction furnace (3), heating the reduction tank (1), starting circulating water of a condensation ladle sleeve (25), starting a magnesium molten pool (23), melting the raw material magnesium placed in the step 2), and keeping the magnesium molten pool (23) at a magnesium metal melting point of above 650 ℃;

5) when the temperature of the reduction tank (1) reaches 1200 +/-10 ℃, the reduction reaction starts, magnesium vapor continuously diffuses into the magnesium crystallizer (2), the magnesium vapor enters a plurality of low-temperature fan blades (21) and then presents a three-dimensional wave-shaped or S-shaped path to advance, and is liquefied or crystallized on the fan blades (21) when meeting cold, meanwhile, part of the magnesium vapor is deposited on the pipe wall of the condensation coating sleeve (25), and tail gas flows out through gaps between the fan blades and the fan blades;

6) when the magnesium crystallization layer on the wall of the fan blade (21) or the condensation casing pipe reaches 5-10mm, reducing or closing the circulating water quantity of a certain area in the cooling casing pipe (25), so that the fan blade in the area is heated by a lower metal guide rod and the circulating water quantity is controlled to raise the temperature to be above 650 ℃ of the melting point of magnesium metal, the crystallized magnesium is heated to start melting, the molten magnesium metal flows downwards along a preset groove (211) on the surface of the fan blade under the action of gravity, and when the molten magnesium metal flows to the metal guide rod at the root of the fan blade, the molten magnesium metal enters a porous pipe and a metal rod bundle (22) formed by the metal guide rod and accelerates to flow into a lower magnesium molten pool (23) under the promotion of capillary action;

7) keeping the temperature of a certain area in the cooling sheath pipe (25) at a temperature of more than 650 ℃ for 1-10 min, recovering the circulating water amount of the area after the crystallized magnesium deposited on the fan blades (21) and the pipe wall of the condensation sheath pipe (25) is melted and removed, and continuously depositing more crystallized magnesium;

8) and then the circulating water quantity of the next area in the cooling jacket pipe (25) is sequentially closed or reduced in the anticlockwise or clockwise direction, the temperature is kept above 650 ℃ for 1-10 min, and the circulation is carried out, so that the continuous extraction of the crystallized magnesium is realized.

Technical Field

The invention relates to a magnesium metallurgy process, in particular to a method and a device for intermittently and continuously extracting crystallized magnesium in magnesium smelting by a Pidgeon process.

Background

The magnesium metal produced by Pidgeon method is made up by using calcined dolomite as raw material, ferrosilicon as reducing agent and fluorite as catalyst through the processes of proportioning and metering. And pressing the mixture into balls after grinding, and the balls are called pellets. The pellets were charged into a reduction pot, heated to 1200 ℃ and internally evacuated to 13.3Pa or more, thereby generating magnesium vapor. The magnesium vapor forms crystalline magnesium, also known as crude magnesium, in a condenser at the front end of the reduction vessel. After the reduction is finished, the vacuum is released, the crystallized magnesium in the crystallization tube is taken out, and the reacted solid magnesium slag is cleaned. And refining the crystallized magnesium by a flux to produce a commercial magnesium ingot, namely a process of refined magnesium.

Although the method has the problems of high energy consumption, serious pollution, low single tube yield, low crystallization efficiency and the like, the method still is the mainstream process of the magnesium metallurgy at present due to low investment, convenient operation and low cost. Aiming at the crystallization and extraction of magnesium vapor, the following 3 problems mainly exist at present, one is that along with the increase of the amount of crystallized magnesium, a temperature gradient is formed between a crystallized magnesium deposition area and a cooling sleeve, and the crystallization rate is reduced; and secondly, the extraction of the crystallized magnesium is to open the vacuum reduction tank after the reaction in the reduction tank is finished, and take out the crystallized magnesium in the cooling area, so that the magnesium metallurgy cannot be continuously produced and has large labor capacity. Thirdly, the crystal magnesium is taken out and cooled to the room temperature, and the crystal magnesium needs to be heated and melted again during refining, thereby causing energy waste. Therefore, if the crystallized magnesium in the crystallization area can be continuously extracted, the crystallization efficiency of magnesium steam can be greatly improved, the waste heat of the crystallized magnesium can be utilized, the continuity of crude magnesium and refining can be realized, and the method has great significance for the improvement of magnesium metallurgy technology.

In recent years, although a crystallizer modification design technology appears, the method basically focuses on establishing a crystallizer model mechanism and optimizing the influence of model parameters on crystallization; the internal structure of the cooling jacket is modified so as to improve the heat-conducting property; considering the influence of temperature gradient and magnesium partial pressure on nucleation and condensation of magnesium vapor, etc., the related art is basically semi-empirical or is over-idealized or complicated, and thus has not been put into practical use. No report is found about the continuous extraction of crystalline magnesium in the Pidgeon magnesium smelting process.

In summary, the extraction of crystallized magnesium in the Pidgeon magnesium smelting process has the following problems:

1. the area of a crystallized magnesium crystallization area is limited, the crystallization efficiency and the total amount are influenced, and the single-tube capacity of a reduction tank is restricted;

2. to be safe, the crystalline magnesium needs to be extracted at room temperature. Refined magnesium needs to be heated and melted again, so that energy waste is serious;

3. the extraction process of the crystallized magnesium also needs manual operation, and has high labor intensity and poor working environment.

4. The continuous extraction of the crystallized magnesium can not be realized, and the continuous process of the magnesium metallurgy technology is restricted.

Disclosure of Invention

In order to solve the above defects in the prior art, the present invention aims to provide a method for improving crystallization efficiency and reducing energy consumption; the device has good production continuity and reduces the labor intensity and is a method and a device for intermittently and continuously extracting the crystallized magnesium in the Pidgeon magnesium smelting process.

In order to achieve the purpose, the device comprises a reduction tank arranged in a reduction furnace and a magnesium crystallizer communicated with the reduction tank, wherein the magnesium crystallizer comprises a condensation sheath pipe and a magnesium molten pool which are arranged in a closed space from top to bottom, one end of the condensation sheath pipe is provided with a magnesium steam inlet end coaxially connected with the reduction tank, the other end of the condensation sheath pipe is provided with a tail gas outlet, a metal rod bundle with fan blades is arranged between the condensation sheath pipe and the magnesium molten pool, the lower end of the metal rod bundle is inserted into the magnesium molten pool, and the fan blades at the upper end of the metal rod bundle are positioned in the condensation sheath pipe.

The metal rod bundle is formed by inserting at least four fan blades which are staggered up and down, left and right and metal rods at the lower parts of the fan blades into a metal pipe in a binding mode, and inserting the metal pipe bundle penetrating through a metal pipe bundle penetrating area of a condensation coating sleeve into a magnesium molten pool.

The metal rod bundle is formed by tightly winding metal wires made of the same material on a metal rod and is inserted into a magnesium molten pool through a metal tube bundle passing area of a condensation coating sleeve.

The fan blade surfaces of the fan-shaped pieces are opposite to the axial direction in the condensation sheath pipe, the fan surfaces of the axially adjacent fan-shaped pieces are alternated up and down and left and right, the alternating distance is 20mm, and the distance between the fan surfaces of the fan-shaped pieces and the condensation sheath pipe is 20 mm.

The grooves of the fan blades are wavy grooves along the direction of the metal rod bundle.

The cooling sheath pipe is divided into more than four cooling areas with inlet and outlet circulating cooling water along the axial direction.

The intermittent continuous extraction process of crystallized magnesium from Pidgeon magnesium includes the following steps:

1) adding a reducing material of magnesium into a reduction tank;

2) adding raw material magnesium into a magnesium molten pool to ensure that the bottom of the magnesium molten pool is submerged in the metal rod bundle;

3) under the vacuum condition, before starting the equipment, synchronously vacuumizing the magnesium crystallizer and the reduction tank, wherein the vacuum degree is 3-15 Pa;

or synchronously finishing the replacement of argon or helium by the magnesium crystallizer and the reduction tank in the argon or helium state;

4) starting the reduction furnace, heating the reduction tank, starting circulating water of a condensing ladle sleeve, starting a magnesium molten pool at the same time, melting the raw material magnesium placed in the step 2), and keeping the magnesium molten pool at a magnesium metal melting point of more than 650 ℃;

5) when the temperature of the reduction tank reaches 1200 +/-10 ℃, the reduction reaction starts, magnesium vapor continuously diffuses into the magnesium crystallizer, the magnesium vapor enters a plurality of low-temperature fan blades and then takes a three-dimensional wave-shaped or S-shaped path to advance, and is liquefied or crystallized on the fan blades when meeting cold, meanwhile, part of the magnesium vapor is deposited on the pipe wall of the condensation sheath pipe, and tail gas flows out through gaps between the fan blades and the fan blades;

6) when the magnesium crystal layer on the fan blade 21 or the wall of the condensing pipe reaches 5-10mm, reducing or closing the circulating water quantity of a certain area in the cooling jacket pipe, so that the fan blade in the area is heated by a lower metal guide rod and controlled by the circulating water quantity to raise the temperature to be above 650 ℃ of the melting point of magnesium metal, the crystallized magnesium is heated to melt, the molten magnesium metal flows downwards along a preset groove on the surface of the fan blade under the action of gravity, and when the molten magnesium metal flows to the metal guide rod at the root of the fan blade, the molten magnesium metal enters a porous pipe and a metal rod bundle consisting of the metal guide rods and accelerates to flow into a lower magnesium molten pool under the promotion of capillary action;

7) keeping the temperature of a certain area in the cooling sheath pipe at a temperature of more than 650 ℃ for 1-10 min, recovering the circulating water quantity of the area after the crystallized magnesium deposited on the fan blades and the pipe wall of the condensation sheath pipe is melted and removed, and continuously depositing more crystallized magnesium;

8) and sequentially closing or reducing the circulating water quantity of the next area in the cooling jacket pipe in the anticlockwise or clockwise direction, keeping the temperature above 650 ℃ for 1-10 min, and circulating in such a way to realize continuous extraction of the crystallized magnesium.

Due to the adoption of the technical scheme, the invention has the following beneficial effects:

1. because the fan blade surfaces are over against the axial direction of the crystallization tube, and the adjacent fan blades in the axial direction are alternated up and down and left and right, the magnesium vapor advances in a three-dimensional wave-shaped or S-shaped path, the crystallization path is prolonged, the crystallization area is increased, the crystallization efficiency is improved, and a solid foundation is laid for improving the single-pot productivity.

2. The invention keeps the temperature of the cooling fan blades above 650 ℃ (the melting point of magnesium metal) all the time due to the heat conduction of the metal rod bundle. The liquid magnesium or the crystallized magnesium on the fan blades is in a molten state and flows downwards to a magnesium molten pool along the preset grooves on the fan blades under the action of gravity and capillary action of the metal rod bundles. The crystallized magnesium does not need to be cooled to room temperature for extraction, and the energy waste is reduced.

Furthermore, the metal rods at the lower parts of the small fan blades in each layer of fan blade surface are bundled together and inserted into the metal pipe, or the metal rods are tightly wound into the metal rod bundle by using metal wires made of the same material. And the metal rod bundles are inserted into the magnesium smelting furnace below the surface of the magnesium melt through the cooling pipe. The continuous operation is realized, the automation degree is high, the environment is good, and the labor intensity is reduced.

The fan-shaped piece is inserted into the condensing pipe, so that the crystallized magnesium flows downwards to the magnesium refining pool along the groove preset on the fan blade under the action of gravity and capillary of the metal rod bundle for direct refining, and the integration of crystallization and extraction of magnesium and the integration of primary refining and refining are realized.

Drawings

FIG. 1 is a schematic structural view of a Pidgeon magnesium smelting device;

FIG. 2 is a schematic view of a magnesium crystallizer according to the present invention;

FIG. 3 is a block diagram of a fan blade according to the present invention;

FIG. 4 is a cross-sectional view A-A of the condensation sleeve of FIG. 2 according to the present invention.

The reference numbers in the figures denote: 1. a reduction tank; 2. a magnesium crystallizer; and a reduction furnace 3. 21. A fan blade; 22. a bundle of metal rods; 23. a magnesium bath; 24. a furnace mouth, 25, a condensation sleeve, 26, a magnesium vapor inlet end, 27 and a tail gas outlet. 211. And (4) a groove. 2111. The bundle of metal tubes passes through the zone.

Detailed Description

The present invention will now be described in detail with reference to the drawings and specific embodiments, wherein the exemplary embodiments and descriptions of the present invention are provided to explain the present invention without limiting the invention thereto.

As shown in fig. 1, the present invention includes a reduction tank 1 disposed in a reduction furnace 3 and a magnesium crystallizer 2 communicated with the reduction tank 1.

As shown in figure 2, the magnesium crystallizer 2 of the magnesium crystallizer 2 comprises a condensing ladle sleeve 25 and a magnesium molten pool 23 which are arranged in a closed space from top to bottom, so that the whole magnesium smelting process can be carried out under an argon or vacuum system. One end of the condensation cladding sleeve 25 is provided with a magnesium vapor inlet end 26 coaxially connected with the reduction pot 1, the other end is provided with a tail gas outlet 27, a metal rod bundle 22 with fan blades 21 is arranged between the condensation cladding sleeve 25 and the magnesium molten pool 23, the outer side of the metal rod bundle 22 is sleeved with a perforated pipe, the lower end of the metal rod bundle is inserted into the magnesium molten pool 23, and the fan blades 21 at the upper end of the metal rod bundle 22 are positioned in the condensation cladding sleeve 25. Wherein the metal rod bundle 22 is formed by inserting at least four fan blades 21 staggered up and down, left and right and metal rods at the lower part thereof into the metal tube in a bundling manner and inserting the metal tube bundle passing region 2111 passing through the condensation coating tube 25 into the magnesium molten pool 23. Or the metal rod bundle 22 is formed by tightly winding metal wires made of the same material on the metal rods to form a metal rod bundle with fan blades 21, and the metal rod bundle penetrating through the metal tube bundle penetrating area 2111 of the condensation sheath tube 25 is inserted into the magnesium molten pool 23. The fan blade surfaces of the fan-shaped sheets 21 are opposite to the axial direction of the metal rod bundle 22, the fan surfaces of the axially adjacent fan-shaped sheets 21 are alternated up and down, left and right, the alternating distance is 20mm, and the distance between the fan surfaces of the fan-shaped sheets 21 and the condensation sheath pipe 25 is 20 mm.

As shown in FIG. 3, for the fan-shaped fins 21 made of high thermal conductivity material, the fan-shaped faces are opposite to the axial direction of the crystallization tube, the adjacent fan-shaped faces in the axial direction are alternated from top to bottom or from left to right, the distance between the adjacent fan-shaped faces in the axial direction is about 20mm, and the distance between the top, the bottom or the left and right sides of the adjacent fan-shaped faces in the axial direction is about 20 mm. In addition, the grooves 211 of the fan blades 21 are wave-shaped grooves along the direction of the metal rod bundle, so that the magnesium melt can flow downwards along the grooves to the metal rod bundle under the action of gravity.

As shown in fig. 4, the cooling jacket 25 is divided into 4 areas with the number of the areas (i), ii, iii, and iv) equally along the axial direction, each area has the circulating cooling water flowing in and out, and the bottommost area is the metal tube bundle passing area 2111.

The device can be used for intermittently and continuously extracting the crystallized magnesium in the Pidgeon magnesium smelting process:

1) adding a reducing material of magnesium into a reduction tank (1);

2) adding raw material magnesium into a magnesium molten pool (23) to ensure that the bottom of the magnesium molten pool is submerged in the metal rod bundle (22);

3) under the vacuum condition, before the equipment is started, synchronously vacuumizing the magnesium crystallizer (2) and the reduction tank (1) at the vacuum degree of 3-15 Pa;

or synchronously finishing the replacement of argon or helium by the magnesium crystallizer (2) and the reduction tank (1) in the state of argon or helium;

while checking the operational stability of the device.

4. The reduction furnace 3 is started, the reduction tank 1 is heated, and the circulating water of fig. 4 is started so that the fan blades 21 are at a relatively low temperature to promote the crystallization of magnesium vapor. And starting the magnesium molten pool 23, melting the raw material magnesium placed in the step 2, and keeping the melting point (650 ℃) of magnesium metal above.

5. When the temperature of the reduction tank 1 reaches the reaction temperature of 1200 +/-10 ℃, the reduction reaction starts, and the reaction formula isMagnesium vapor continuously diffuses into the magnesium crystallizer 2, the magnesium vapor presents a three-dimensional wave-shaped or S-shaped path after encountering a plurality of layers of fan blades 21 made of high heat conduction materials at low temperature, is liquefied or crystallized on the fan blades 21 when encountering cold, and is partially deposited on the pipe wall of a condensation sheath pipe 25, and tail gas flows out through gaps between the fan blades.

6. When the magnesium crystal layer on the fan blade 21 or the wall of the condensing pipe reaches 5-10mm, the circulating water quantity (such as the region I) in one region is reduced or closed, so that the fan blade in the region is controlled by the lower metal guide rod (heating) and the circulating water (cooling) to increase the temperature to be above the melting point (650 ℃) of magnesium metal, and the crystallized magnesium is heated and starts to melt. The molten magnesium metal flows downward along the predetermined grooves 211 on the blade surface under the action of gravity. When the molten metal magnesium liquid flows to the metal guide rod at the root of the fan blade, the molten metal magnesium liquid enters an axial porous pipe and a metal rod bundle 22 which are formed by the guide rod, and the molten metal magnesium liquid is accelerated to flow into a lower magnesium molten pool 23 under the promotion of the capillary action;

7. keeping the temperature of a certain area in the cooling sheath tube 25 at 650 ℃ for 1-10 min, and recovering the circulating water volume of the area after the crystallized magnesium deposited on the fan blades 21 and the tube wall of the condensation sheath tube 25 is melted and removed, so as to continuously deposit more crystallized magnesium;

8. then, the circulating water quantity of the next area (II or IV) of the cooling jacket pipe 25 is sequentially reduced in a counterclockwise or clockwise sequence, the temperature is kept above 650 ℃ for a certain time (1-10 min), and the continuous extraction of the crystallized magnesium is realized through the circulation;

the fan-shaped pieces are inserted into the condensing tube, the fan blade surfaces are opposite to the axial direction of the crystallizing tube, and the adjacent fan blades in the axial direction are alternated up and down and left and right, so that magnesium vapor advances in a three-dimensional wavy or S-shaped path, the crystallizing path is prolonged, the crystallizing area is increased, the depositing area of crystallized magnesium is obviously increased, the depositing chance is increased, and the crystallizing efficiency is improved. Over time, a large amount of crystalline magnesium deposits on the front and back of the fan blade. When the time is too long, the excessively thick crystallized magnesium layer can block gaps among the fan blades, the pipe wall and the small fan blades, and the crystallization efficiency is seriously influenced. Therefore, the high heat conduction metal rods at the lower parts of the small fan blades in the fan blade surface of one layer are bound together and inserted into the metal pipe, or the metal rods are tightly wound into a metal rod bundle by using metal wires made of the same material. The metal rod bundles are inserted through a cooling pipe below the surface of the magnesium melt in the magnesium smelting furnace. The temperature of the cooling fan blade is always kept above 650 ℃ (the melting point of magnesium metal) by the heat conduction of the metal rod. In order to control the extraction temperature, a plurality of groups of cooling sections are arranged on the cooling pipe synchronously. According to the crystallization law of magnesium vapor, the amount of cooling water is adjusted to control the temperature of different sections of crystallization fan blade areas, so that liquid magnesium or crystallized magnesium on the fan blades is in a molten state and flows downwards to a magnesium molten pool along a groove preset on the fan blades under the action of gravity and capillary action of a metal rod bundle. And repeating the steps to finish the continuous extraction of the crystallized magnesium on the fan blades in the cooling section.