A device and method for preparing ultra-high purity low melting point metal with high yield

Abstract

This invention discloses a high-yield apparatus for preparing ultra-high purity low-melting-point metals, comprising a metal oxide ceramic reactor. A movable constant-temperature heating jacket and a constant-temperature cooling jacket are sequentially arranged on the metal oxide ceramic reactor. The reactor is connected to a tilting device, with an opening connected to a condenser collector and a vacuum generator. The invention also discloses a preparation method: 1. The low-melting-point metal to be purified is placed in the metal oxide ceramic reactor, then a vacuum is drawn and the reactor is heated to melt. 2. The tilt angle of the metal oxide ceramic reactor is adjusted, a vacuum is drawn, and hydrogen gas is introduced for cooling. 3. The operation is repeated. 4. Cooling is performed after the gas supply is stopped. This invention, by circling the metal oxide ceramic reactor with a movable constant-temperature heating jacket and a constant-temperature cooling jacket and connecting them to a tilting device, avoids the backflow of impurities in the liquid low-melting-point metal to be purified, increases the liquid / gas interface area, and improves the metal purification effect.

Description

Technical Field

[0001] This invention belongs to the field of ultra-high purity material preparation technology, specifically relating to an apparatus and method for preparing ultra-high purity low melting point metals with high yield. Background Technology

[0002] Improving the purity of metallic materials such as indium, tin, gallium, and germanium is beneficial for further enhancing their physicochemical properties. Therefore, with the vigorous development of high-tech fields such as new energy, optoelectronics, aerospace, and national defense, the demand for high-purity metallic materials will continue to increase. With the rapid development of the semiconductor industry in recent years, mastering stable preparation processes for high-quality ultra-high-purity metals and achieving industrial-scale production capacity for ultra-high-purity metals is of great significance for promoting the development of related fields.

[0003] Zone melting is a traditional method for purifying metallic materials. Its essence lies in locally heating a narrow ingot to form one or more narrow molten zones, rather than melting the entire ingot. The heater is then moved so that these narrow molten zones slowly move along the ingot in a specific direction. Utilizing the difference in concentration between the solid and liquid phases of impurities, the impurities segregate into the solid or liquid phase and are removed during repeated melting and solidification. Impurity elements are driven from one end of the ingot to the other, thus achieving metal purification. Taking indium as an example, zone melting can remove impurities that do not react with indium, such as boron (B), eugenol (Au), argon (Ag), and nickel (Ni). However, impurities such as sulfur (S), selenium (Se), and terephthalium (Te) have a higher affinity for indium and are difficult to separate using zone melting. Therefore, to obtain ultra-high purity indium, it is necessary to combine it with other purification processes to remove impurity elements that zone melting cannot remove. However, because the combined processes must be carried out in different equipment, cross-contamination of samples can occur, significantly reducing the yield and increasing the operational difficulty and preparation cycle of ultra-high purity materials.

[0004] Furthermore, in traditional zone melting operations, because the ingots are placed horizontally, during the movement of the heater, the liquid ingots, after melting into a liquid state, become fluid. Liquid with a higher impurity content will simultaneously flow in the opposite direction of the heater's movement, resulting in impurity element backflow. This makes it difficult to deeply remove impurities from the product, failing to achieve the desired impurity removal effect. The crucibles in traditional zone melting are made of quartz, which has good wettability with the molten liquid metal, causing significant adhesion of the metal within the crucible. On the one hand, this adhered metal cannot separate from the quartz, greatly reducing the yield; on the other hand, adhesion reduces the fluidity of the metal, preventing some impurities from being effectively separated at the liquid / solid interface, thus hindering further improvement in the purity of the metal material. Since some metallic impurities can only be removed through zone melting, these shortcomings have led to a technical bottleneck in the purification of ultra-high purity materials.

[0005] Therefore, there is an urgent need to obtain a high-yield, high-efficiency apparatus and method for preparing ultra-high purity metals suitable for industrial production. Summary of the Invention

[0006] The technical problem to be solved by this invention is to provide a high-yield apparatus for preparing ultra-high purity low-melting-point metals, addressing the shortcomings of the prior art. This apparatus consists of a movable constant-temperature heating jacket and a constant-temperature cooling jacket sequentially arranged around a metal oxide ceramic reactor, which is then connected to a tilting device. Through the design of the temperature and gravity fields of the apparatus, the backflow of impurities in the liquid low-melting-point metal to be purified is effectively avoided. Furthermore, the angle between the solid / liquid and liquid / gas interfaces and the metal oxide ceramic reactor during the melting and solidification process of the low-melting-point metal is controlled, increasing the liquid / gas interface area, improving the metal purification effect, and enhancing the purity of the metal product, thus solving the problem of difficulty in improving the purity of metal materials.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: a preparation device for ultra-high purity low melting point metal with high yield, characterized in that it includes a metal oxide ceramic reactor, on which a movable constant temperature heating jacket and a constant temperature cooling jacket are sequentially arranged, and the constant temperature heating jacket is arranged above the constant temperature cooling jacket. The metal oxide ceramic reactor is connected to a tilter, and the opening of the metal oxide ceramic reactor is connected to a condenser collector. The metal oxide ceramic reactor is also connected to a vacuum generator.

[0008] The above-mentioned apparatus for preparing ultra-high purity low melting point metal with high yield is characterized in that the metal oxide ceramic reactor is made of alumina or zirconium oxide.

[0009] The above-mentioned apparatus for preparing ultra-high purity low melting point metal with high yield is characterized in that the inner diameter d of the metal oxide ceramic reactor and the length a of the constant temperature heating jacket, and the inclination angle α between the metal oxide ceramic reactor and the horizontal plane satisfy the following condition: a>d / tanα.

[0010] In addition, the present invention also discloses a method for preparing ultra-high purity low-melting-point metals using the apparatus described above, characterized in that the method includes the following steps: Step 1: Place the low-melting-point metal to be purified into the metal oxide ceramic reactor, then turn on the vacuum generator and the constant temperature heating mantle to evacuate the metal oxide ceramic reactor, and adjust the heating zone of the constant temperature heating mantle to temperature T1 to heat and melt the low-melting-point metal to be purified. Step 2: Adjust the tilt angle of the metal oxide ceramic reactor to the horizontal plane to α using the tilter, open the constant temperature cooling jacket, continue to evacuate the metal oxide ceramic reactor, then introduce hydrogen gas, adjust the heating zone of the constant temperature heating jacket to temperature T2, and the cooling zone of the constant temperature cooling jacket to temperature T3, to cool the molten low melting point metal to be purified. Step 3: Moving the constant temperature heating jacket and constant temperature cooling jacket synchronously and uniformly from the bottom to the head of the metal oxide ceramic reactor, and repeating the operation more than 10 times to obtain a metal block; Step 4: Close the constant temperature heating jacket, stop the flow of hydrogen into the metal oxide ceramic reactor, and maintain the vacuum temperature. Then close the constant temperature cooling jacket, allow it to cool naturally, and then close the vacuum generator. Remove the metal block and cut off the surface metal at the liquid / gas interface to obtain ultra-high purity low melting point metal.

[0011] The method described above is characterized in that the low-melting-point metal to be purified in step one is gallium, germanium, indium, tin, antimony, tellurium, thallium, lead, or bismuth.

[0012] The above method is characterized in that, in step one, the vacuum degree inside the metal oxide ceramic reactor after vacuuming is 1 Pa to 50 Pa, and the temperature T1 is above 100°C of the melting point of the low-melting-point metal to be purified and below 100°C of its boiling point. By controlling the temperature T1, this invention maximizes the difference between the volatile impurity elements in the low-melting-point metal to be purified and the saturated vapor pressure of the metal itself, while preventing the metal from reaching its boiling point and volatilizing. This improves the separation coefficient between the metal and impurities, enabling effective separation, and reduces the loss of the metal, thus increasing the yield. Furthermore, by controlling the vacuum degree to be below atmospheric pressure without requiring a high vacuum, this invention ensures efficient separation of the metal and impurities, eliminates the need for high-vacuum equipment such as molecular pumps, reduces costs, and prevents impurities from volatilizing into precision equipment like molecular pumps and causing malfunctions.

[0013] The above method is characterized in that, in step two, the vacuum level inside the metal oxide ceramic reactor after continued vacuuming is 10. -3Below Pa, the hydrogen gas has a purity of 99.9999% or higher. Temperature T2 is within 100°C above the melting point of the low-melting-point metal to be purified, and temperature T3 is below 100°C above the melting point of the low-melting-point metal to be purified. This invention controls temperature T2 to be within 100°C above the melting point of the low-melting-point metal to be purified, rather than higher, to control the interface between the liquid and solid phases and the melting width during the melting-solidification process of the low-melting-point metal to be purified. This avoids excessively high temperatures that would cause nearby metals with good thermal conductivity to reach their melting point, making it difficult to achieve regional melting. This invention controls temperature T3 to be below 100°C above the melting point of the low-melting-point metal to be purified, ensuring a temperature difference of at least 100°C between the heating melting zone and the cooling solidification zone, thereby ensuring regional melting and preventing the metal in the surrounding area from melting due to thermal conductivity. Simultaneously, this invention controls the vacuum level of the process to be 10... -3 The pressure is kept below Pa to ensure that all air and residual gaseous impurities volatilized from the previous heating and melting process are completely removed from the ceramic reactor before hydrogen is introduced, including gaseous impurities such as O and N that have a contaminating effect on the low-melting-point metal to be purified, so as to ensure that the purity of the obtained ultra-high purity low-melting-point metal meets the 7N requirement.

[0014] The method described above is characterized in that the synchronous uniform movement speed in step three is 1 mm / h to 100 mm / h.

[0015] The method described above is characterized in that the heat preservation time in step four does not exceed 1 hour.

[0016] Compared with the prior art, the present invention has the following advantages: 1. The preparation apparatus of the present invention consists of a movable constant-temperature heating jacket and a constant-temperature cooling jacket arranged sequentially around a metal oxide ceramic reactor, and the metal oxide ceramic reactor is connected to a tilter. By designing the temperature field and gravity field of the apparatus, the backflow of impurities in the liquid low-melting-point metal to be purified is effectively avoided, and the angle between the solid / liquid and liquid / gas interfaces and the metal oxide ceramic reactor during the melting-solidification process of the low-melting-point metal to be purified is controlled, thereby increasing the liquid / gas interface area, improving the metal purification effect, and increasing the purity and yield of the metal product.

[0017] 2. The preparation apparatus of the present invention connects a metal oxide ceramic reactor with a vacuum generator and a condenser to ensure that the melting-solidification process of the low-melting-point metal to be purified is carried out under vacuum conditions. This promotes the volatilization and escape of elements with higher affinity to the low-melting-point metal to be purified into the condenser for separation, thus avoiding secondary pollution caused by them entering the liquid low-melting-point metal to be purified. This achieves the removal of impurities from difficult-to-separate substances.

[0018] 3. By limiting the reactor to a metal oxide ceramic material, this invention avoids adhesion between the reactor inner wall and the molten liquid low-melting-point metal to be purified, promotes metal flow and mass transfer at the interface between the low-melting-point metal to be purified and the reactor in the liquid state, facilitates the separation of impurity elements at the liquid / solid interface, thereby improving the purity and yield of the purified metal.

[0019] 4. The preparation method of the present invention is fast, simple and easy to implement. The finished ultra-high purity metal ingot can be directly produced on the same equipment without further cleaning, remelting and other operations. The process is short, efficient and has a high yield.

[0020] 5. In the preparation process of this invention, hydrogen is used to remove gaseous impurity elements such as oxygen (O), which further reduces the impurity content in ultra-high purity low melting point metal materials, resulting in extremely high product purity, reaching 7N (99.99999%) or higher.

[0021] 6. The preparation method of the present invention has wide applicability and has excellent impurity removal effect on low melting point metal materials such as gallium, germanium, indium, tin, antimony, tellurium, thallium, lead, and bismuth, and has wide applicability.

[0022] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the apparatus for preparing ultra-high purity low melting point metal with high yield according to the present invention.

[0024] Explanation of reference numerals in the attached figures Detailed Implementation

[0025] The apparatus for preparing ultra-high purity low melting point metal with high yield of the present invention is described in detail through Example 1.

[0026] Example 1 like Figure 1 As shown, the apparatus for preparing ultra-high purity low melting point metal with high yield in this embodiment includes a metal oxide ceramic reactor 1. A movable constant temperature heating jacket 2 and a constant temperature cooling jacket 3 are sequentially arranged on the metal oxide ceramic reactor 1, and the constant temperature heating jacket 2 is arranged above the constant temperature cooling jacket 3. The metal oxide ceramic reactor 1 is connected to a tilter 4. A condenser collector 6 is connected to the opening of the metal oxide ceramic reactor 1, and the metal oxide ceramic reactor 1 is connected to a vacuum generator 5.

[0027] In this embodiment, the apparatus for preparing ultra-high purity low-melting-point metals with high yield is equipped with a metal oxide ceramic reactor 1 as the container for the low-melting-point metal to be purified and the place for melting and purifying the low-melting-point metal. By using a reactor made of metal oxide ceramic material, on the one hand, the high temperature resistance of metal oxide ceramic material is utilized to ensure the smooth progress of melting and purification. On the other hand, the wetting angle between the metal oxide ceramic material and the molten liquid low-melting-point metal to be purified is large, making it less prone to adhesion and facilitating contact between the low-melting-point metal to be purified and the reactor in the liquid state. The metal flow and mass transfer at the interface facilitate the separation of impurity elements at the liquid / solid interface, thereby improving the purity and yield of the purified metal. In this embodiment, the preparation apparatus consists of a movable constant-temperature heating jacket 2 and a constant-temperature cooling jacket 3 arranged sequentially around a metal oxide ceramic reactor 1, with the heating jacket 2 positioned above the cooling jacket 3. The heating effect of the heating jacket 2 locally heats the low-melting-point metal to be purified inside the metal oxide ceramic reactor 1, causing the metal within its heating zone to melt into the liquid phase, forming a molten zone. The cooling effect of the constant-temperature cooling jacket 3 causes the liquid low-melting-point metal to be purified, which has been melted by the constant-temperature heating jacket 2 and is located in its cooling zone, to rapidly solidify into a solid phase, forming a solidification zone. Based on the difference in the equilibrium concentration of impurities in the low-melting-point metal to be purified between the solid and liquid phases, impurities segregate into the liquid phase during the melting-solidification process. Combined with the movable nature of the constant-temperature heating jacket 2 and the constant-temperature cooling jacket 3, they move in a certain direction along the interior of the metal oxide ceramic reactor 1 containing the low-melting-point metal to be purified. Typically, they move along the interior of the metal oxide ceramic reactor... The bottom of the device 1 moves towards the head, causing the low-melting-point metal to be purified to melt sequentially along the moving direction, forming several molten and solidified zones. The melting-solidification process is repeated continuously, so that impurities in the low-melting-point metal to be purified in each molten zone are segregated into the liquid phase, making them easier to remove later. This achieves the purification of the metal and obtains high-purity metal. Furthermore, the movable constant-temperature heating jacket 2 and constant-temperature cooling jacket 3 are controlled to repeat the above moving process multiple times, achieving repeated purification of the low-melting-point metal to be purified, fully removing impurities in the low-melting-point metal to be purified, and obtaining ultra-high-purity metal.

[0028] In this embodiment, the preparation apparatus connects the metal oxide ceramic reactor 1 to the tilter 4. On one hand, the tilter 4 ensures that the liquid surface of the low-melting-point metal to be purified remains flush with the horizontal plane during the melting process, flowing continuously from the bottom to the top of the reactor 1. This effectively prevents impurities in the liquid low-melting-point metal from flowing back into the cooled solid metal, thereby further improving the purity of the metal product. On the other hand, the tilter 4 adjusts and controls the tilt angle of the metal oxide ceramic reactor 1 relative to the horizontal plane, thereby controlling the angle between the solid / liquid and liquid / gas interfaces and the reactor during the melting-solidification process of the low-melting-point metal. This increases the liquid / gas interface area, improves the purification effect, and thus increases the yield of ultra-high purity low-melting-point metal. Furthermore, the optimal tilt angle can be obtained by calculating the temperature distribution at the interface formed by the tilt, achieving the best purification effect.

[0029] In the preparation apparatus of this embodiment, a condenser 6 is connected to the opening of the metal oxide ceramic reactor 1 to collect volatile impurity elements during the melting process. At the same time, the metal oxide ceramic reactor 1 is connected to a vacuum generator 5 to maintain the vacuum level of the metal oxide ceramic reactor 1 and avoid introducing air impurities. More importantly, the melting-solidification conditions of the vacuum are controlled to promote the volatilization and separation of elements with higher affinity to the low melting point metal to be purified, which then enter the condenser 6, preventing them from entering the liquid low melting point metal to be purified and causing secondary pollution.

[0030] Furthermore, the movable constant-temperature heating jacket 2 and constant-temperature cooling jacket 3 are fitted onto the metal oxide ceramic reactor 1 to facilitate movement, ensure the continuous melting-solidification process, and improve preparation efficiency.

[0031] Furthermore, the metal oxide ceramic reactor 1 is made of alumina or zirconium oxide.

[0032] Furthermore, the inner diameter d of the metal oxide ceramic reactor 1, the length a of the constant temperature heating jacket 2, and the inclination angle α between the metal oxide ceramic reactor 1 and the horizontal plane satisfy the condition: a > d / tanα. Through these constraints, on the one hand, it is ensured that the liquid / solid interface is perpendicular to the moving direction of the constant temperature heating jacket 2 during the melting-solidification process of the low-melting-point metal to be purified. This makes the heat and mass transfer processes at the interface more controllable, which is beneficial for improving the yield and ensuring the impurity removal effect. On the other hand, the liquid phase region can be used to isolate the solid and gas phases, which is beneficial for ensuring the stability of the system in the liquid / solid phase region and avoiding mass migration during the purification process, thus preventing contamination of the purified metal.

[0033] The preparation method of the ultra-high purity low melting point metal of the present invention is described in detail through Examples 2 to 4.

[0034] Example 2 This embodiment includes the following steps: Step 1: Place the indium to be purified (99.99% purity) into a metal oxide ceramic reactor 1 made of zirconium oxide (99.99% purity). Position the constant-temperature heating jacket 2 at the bottom of the metal oxide ceramic reactor 1. Then, turn on the vacuum generator 5 and the constant-temperature heating jacket 2 to evacuate the metal oxide ceramic reactor 1 to a vacuum level below 50 Pa. Adjust the heating zone of the constant-temperature heating jacket 2 to temperature T1 to heat and melt the indium to be purified. The temperature T1 is above 100°C of the melting point and below 100°C of the boiling point of the indium to be purified. The inner diameter of the metal oxide ceramic reactor 1 is d = 30 mm, and the length of the constant-temperature heating jacket 2 is a = 40 mm. Step 2: Adjust the tilt angle α of the metal oxide ceramic reactor 1 to 45° using the tilter 4, open the constant temperature cooling jacket 3, and continue to evacuate the metal oxide ceramic reactor 1 until the vacuum degree reaches 10. -3 Below Pa, hydrogen gas with a purity of 99.9999% or higher is introduced, and the heating zone of the constant temperature heating jacket 2 is adjusted to temperature T2, and the cooling zone of the constant temperature cooling jacket 3 is adjusted to temperature T3. Temperature T2 is within 100°C above the melting point of the indium to be purified, and temperature T3 is below 100°C above the melting point of the indium to be purified, so as to cool the molten indium to be purified. Step 3: Moving the constant temperature heating jacket 2 and the constant temperature cooling jacket 3 synchronously and uniformly at a speed of 1 mm / h along the bottom to the head of the metal oxide ceramic reactor 1, and repeating the operation 10 times to obtain the indium block; Step 4: Close the constant temperature heating jacket 2, stop the flow of hydrogen into the metal oxide ceramic reactor 1, and maintain the vacuum temperature for 1 hour. Then close the constant temperature cooling jacket 3, and after natural cooling, close the vacuum generator 5. Remove the indium block and cut off the surface metal at the liquid / gas interface to obtain ultra-high purity low melting point indium product.

[0035] Testing revealed that the purity of the ultra-high purity low melting point indium product prepared in this embodiment was 7N, and the direct yield was 75%.

[0036] In this embodiment, the low-melting-point metal to be purified can also be replaced with gallium, germanium, tin, antimony, tellurium, thallium, lead, or bismuth.

[0037] Example 3 This embodiment includes the following steps: Step 1: Place the tin to be purified (99.99% purity) into a metal oxide ceramic reactor 1 made of aluminum carbide (99.99% purity). The constant-temperature heating jacket 2 is positioned at the bottom of the metal oxide ceramic reactor 1. Then, turn on the vacuum generator 5 and the constant-temperature heating jacket 2 to evacuate the metal oxide ceramic reactor 1 to a vacuum level below 30 Pa. Adjust the heating zone of the constant-temperature heating jacket 2 to temperature T1 to heat and melt the tin to be purified. The temperature T1 is above the melting point of the tin and below its boiling point. The inner diameter of the metal oxide ceramic reactor 1 is d = 30 mm, and the length of the constant-temperature heating jacket 2 is a = 20 mm. Step 2: Adjust the tilt angle α of the metal oxide ceramic reactor 1 to 60° using the tilter 4, open the constant temperature cooling jacket 3, and continue to evacuate the metal oxide ceramic reactor 1 until the vacuum degree reaches 2×10⁻⁶. -3 Below Pa, hydrogen gas with a purity of 99.9999% or higher is introduced, and the heating zone of the constant temperature heating jacket 2 is adjusted to temperature T2, and the cooling zone of the constant temperature cooling jacket 3 is adjusted to temperature T3. Temperature T2 is within 800°C above the melting point of the tin to be purified, and temperature T3 is below 100°C above the melting point of the tin to be purified, so as to cool the molten tin to be purified. Step 3: Moving the constant temperature heating jacket 2 and the constant temperature cooling jacket 3 synchronously and uniformly at a speed of 100 mm / h along the bottom to the head of the metal oxide ceramic reactor 1, and repeating the operation 15 times to obtain the indium block; Step 4: Close the constant temperature heating jacket 2, stop the introduction of hydrogen into the metal oxide ceramic reactor 1, and maintain the vacuum temperature for 4 hours. Then close the constant temperature cooling jacket 3, and after natural cooling, close the vacuum generator 5. Take out the tin block and remove the surface metal at the liquid / gas interface to obtain ultra-high purity low melting point tin product.

[0038] Testing revealed that the purity of the ultra-high purity low melting point tin product prepared in this embodiment was 7N, and the direct yield was 78%.

[0039] Example 4 This embodiment includes the following steps: Step 1: Place the gallium to be purified (99.99% purity) into a metal oxide ceramic reactor 1 made of titanium boride (99.99% purity), with the constant temperature heating jacket 2 located at the bottom of the metal oxide ceramic reactor 1. Then, turn on the vacuum generator 5 and the constant temperature heating jacket 2 to evacuate the metal oxide ceramic reactor 1 to a vacuum level below 20 Pa, and adjust the heating zone of the constant temperature heating jacket 2 to temperature T1 to heat and melt the gallium to be purified. The temperature T1 is above the melting point of the gallium to be purified and below the boiling point of 300°C. The inner diameter of the metal oxide ceramic reactor 1 is d = 40 mm, and the length of the constant temperature heating jacket 2 is a = 45 mm. Step 2: Adjust the tilt angle α of the metal oxide ceramic reactor 1 to 50° using the tilter 4, open the constant temperature cooling jacket 3, and continue to evacuate the metal oxide ceramic reactor 1 until the vacuum degree is 4×10⁻⁶. -3 Below Pa, hydrogen gas with a mass purity of 99.9999% or higher is introduced, and the heating zone of the constant temperature heating jacket 2 is adjusted to temperature T2, and the cooling zone of the constant temperature cooling jacket 3 is adjusted to temperature T3. Temperature T2 is within 400°C above the melting point of gallium to be purified, and temperature T3 is below 100°C above the melting point of gallium to be purified, so as to cool the molten gallium to be purified. Step 3: Moving the constant temperature heating jacket 2 and the constant temperature cooling jacket 3 synchronously and uniformly at a speed of 50 mm / h along the bottom to the head of the metal oxide ceramic reactor 1, and repeating the operation 12 times to obtain gallium blocks; Step 4: Close the constant temperature heating jacket 2, stop the introduction of hydrogen into the metal oxide ceramic reactor 1, and maintain the vacuum level for 2 hours. Then close the constant temperature cooling jacket 3, and after natural cooling, close the vacuum generator 5. Remove the gallium block and cut off the surface metal at the liquid / gas interface to obtain an ultra-high purity low melting point gallium product.

[0040] Testing revealed that the purity of the ultra-high purity low melting point gallium product prepared in this embodiment was 7N, and the direct recovery rate was 80%.

[0041] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Any simple modifications, alterations, and equivalent changes made to the above embodiments based on the inventive essence shall still fall within the protection scope of the present invention.

Claims

1. An apparatus for preparing ultra-high purity, low-melting-point metals with high yield, characterized in that, The reactor includes a metal oxide ceramic reactor (1), on which a movable constant temperature heating jacket (2) and a constant temperature cooling jacket (3) are sequentially arranged, and the constant temperature heating jacket (2) is arranged above the constant temperature cooling jacket (3). The metal oxide ceramic reactor (1) is connected to a tilter (4). A condenser collector (6) is connected to the opening of the metal oxide ceramic reactor (1). The metal oxide ceramic reactor (1) is connected to a vacuum generator (5). The inner diameter d of the metal oxide ceramic reactor (1) and the length a of the constant temperature heating jacket (2) and the tilt angle α between the metal oxide ceramic reactor (1) and the horizontal plane satisfy the following condition: a>d / tanα.

2. The apparatus for preparing ultra-high purity low-melting-point metal with high yield according to claim 1, characterized in that, The metal oxide ceramic reactor (1) is made of alumina or zirconium oxide.

3. A method for preparing ultra-high purity low-melting-point metals using the apparatus as described in claim 1 or 2, characterized in that, The method includes the following steps: Step 1: Place the low melting point metal to be purified into the metal oxide ceramic reactor (1), then turn on the vacuum generator (5) and the constant temperature heating jacket (2) to evacuate the metal oxide ceramic reactor (1), and adjust the heating zone of the constant temperature heating jacket (2) to temperature T1 to heat and melt the low melting point metal to be purified. Step 2: Adjust the tilt angle of the metal oxide ceramic reactor (1) to the horizontal plane to α using the tilter (4), open the constant temperature cooling jacket (3), continue to evacuate the metal oxide ceramic reactor (1), then introduce hydrogen gas, adjust the heating zone of the constant temperature heating jacket (2) to temperature T2, and the cooling zone of the constant temperature cooling jacket (3) to temperature T3, and cool the molten low melting point metal to be purified. Step 3: Move the constant temperature heating jacket (2) and constant temperature cooling jacket (3) synchronously and uniformly from the bottom to the head of the metal oxide ceramic reactor (1), and repeat the operation more than 10 times to obtain a metal block; Step 4: Close the constant temperature heating jacket (2), stop the hydrogen gas from being introduced into the metal oxide ceramic reactor (1), and keep it warm under the condition of maintaining the vacuum. Then close the constant temperature cooling jacket (3), and after natural cooling, close the vacuum generator (5). Take out the metal block and cut off the surface metal at the liquid / gas interface to obtain ultra-high purity low melting point metal.

4. The method according to claim 3, characterized in that, The low-melting-point metal to be purified in step one is gallium, germanium, indium, tin, antimony, tellurium, thallium, lead, or bismuth.

5. The method according to claim 3, characterized in that, The vacuum level in the metal oxide ceramic reactor (1) after vacuuming in step one is 1Pa~50Pa, and the temperature T1 satisfies: melting point of the low melting point metal to be purified +100℃ ≤ T1 ≤ boiling point of the low melting point metal to be purified -100℃.

6. The method according to claim 3, characterized in that, In step two, the vacuum inside the metal oxide ceramic reactor (1) continues to be evacuated until the vacuum level inside the metal oxide ceramic reactor (1) reaches 10. -3 Below Pa, the mass purity of the hydrogen gas is above 99.9999%, and the temperature T2 satisfies: the melting point of the low-melting-point metal to be purified ≤ T2 ≤ the melting point of the low-melting-point metal to be purified + 100℃, and the temperature T3 satisfies: T3 ≤ the melting point of the low-melting-point metal to be purified - 100℃.

7. The method according to claim 3, characterized in that, The synchronous uniform movement speed described in step three is 1 mm / h to 100 mm / h.

8. The method according to claim 3, characterized in that, The heat preservation time described in step four shall not exceed 1 hour.

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