Device and method for purifying metal through cooperation of external field strengthening and horizontal vacuum distillation

Abstract

The invention relates to the technical field of metal purification, in particular to a device and method for purifying metal through cooperation of external field strengthening and horizontal vacuum distillation. Comprising a horizontal vacuum distillation system which comprises a quartz tube, and a raw material graphite boat, a distillation heater, a condensation collection boat and a steam transition tube which are arranged in the quartz tube; the external field strengthening system comprises at least one of an electromagnetic field generator, an ultrasonic field generator and a microwave field generator which are arranged on the outer wall of the quartz tube; the fractional condensation collection system comprises a plurality of condensation heaters arranged in the quartz tube; the vacuum system comprises a mechanical pump and a diffusion pump which are communicated through a vacuum pipeline, and the diffusion pump is communicated with the quartz tube and used for controlling the vacuum degree in the quartz tube. According to the device and method for purifying the metal through cooperation of external field strengthening and horizontal vacuum distillation, the impurity separation efficiency is high.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal purification, in particular to a device and method for external field strengthening and horizontal vacuum distillation for purifying metal. BACKGROUND

[0002] In the process of metal purification, vacuum distillation is a common physical method of purification process, but it has limitations. The principle of vacuum distillation for purifying metal is that various metal elements have different saturated vapor pressures at a certain temperature. By utilizing the difference in evaporation and condensation speed, impurity elements can be separated from the main metal, so as to achieve the purpose of purifying the main metal. This method has strong adaptability to raw materials, but it is difficult to separate impurities with similar saturated vapor pressure to the main metal, resulting in that part of the impurities cannot meet the requirements of high-purity metal products.

[0003] Chinese patent CN129774555A discloses a method for removing impurity selenium in crude tellurium. An adsorption layer of Al2O3 and carbon reducing agent is placed on the crude tellurium distillation container to separate impurities by adsorbing selenium in tellurium vapor, but the adsorption layer introduced in this method becomes a new source of impurities and is only effective for a single impurity, and cannot achieve deep separation of multiple impurities in a short process. The traditional vertical distillation makes the impurities in the bottom of the melt float up under the action of gravity, forming a gas-liquid mixed interface pollution zone, and the vertical migration of vapor is greatly affected by the gravity field, resulting in impurity condensation backflow. Chinese patent CN127466257A discloses a production device and method for preparing 6N high-purity tellurium by horizontal vacuum distillation. The purity of tellurium can be increased from 5N to 6N by this invention, but the separation effect of the main metal and high-saturated-vapor-pressure impurity metal is limited by relying only on the temperature control of the distillation temperature and the condensation temperature and the secondary condensation pipe, and the removal rate of oxygen and sulfur impurities wrapped in the crystal lattice is low, and the diffusion and migration of impurities in the distillation melt are limited. SUMMARY

[0004] The technical problem to be solved by the present application is to overcome the deficiencies and defects mentioned in the above background, and to provide a device and method for external field strengthening and horizontal vacuum distillation for purifying metal with high impurity separation efficiency.

[0005] To solve the above technical problems, the technical solution of the present application is as follows: a device for external field strengthening and horizontal vacuum distillation for purifying metal, comprising: a horizontal vacuum distillation system, comprising a quartz tube, a raw material graphite boat, a distillation heater, a condensation collection boat and a vapor transition pipe arranged in the quartz tube; an external field strengthening system, comprising at least one of an electromagnetic field generator, an ultrasonic field generator and a microwave field generator arranged on the outer wall of the quartz tube; a staged condensation collection system, comprising a plurality of condensation heaters arranged in the quartz tube; A vacuum system comprising a mechanical pump and a diffusion pump connected by a vacuum pipeline, the diffusion pump being connected to a quartz tube for controlling the vacuum degree in the quartz tube.

[0006] In an embodiment, a phase controller is further included for adjusting the phase difference between the electromagnetic field and the ultrasonic field in real time.

[0007] In an embodiment, the electromagnetic generator comprises a solenoid coil coaxially arranged around the quartz tube, the magnetic field strength being 0.1-5 T and the electromagnetic frequency being 1-100 kHz.

[0008] In an embodiment, the ultrasonic field generator is a piezoelectric ceramic transducer array embedded in the bottom of the quartz tube, the ultrasonic frequency being 20-40 kHz and the sound intensity being ≥10 W / cm².

[0009] In an embodiment, the microwave field generator is arranged at the waveguide port at the top of the quartz tube for vertically radiating the metal raw material contained in the raw material graphite boat, the microwave frequency being 2.45 GHz±50 MHz and the power being 1-10 kW.

[0010] In an embodiment, the condensation collection boat is provided with a multi-stage baffle group.

[0011] In an embodiment, the angle of the single baffle of the baffle group is adjusted in the range of 30-90°.

[0012] In an embodiment, the spacing between the plates of the multi-stage baffle group decreases by 10%-50% along the steam flow direction.

[0013] In an embodiment, the distillation heater comprises alternatingly arranged resistance wires and electromagnetic induction coils, resistance heating being used when the working temperature is lower than 1000℃ and electromagnetic heating being used when the working temperature is higher than 1000℃.

[0014] Based on the same inventive concept, a method for external field reinforced metal purification is also provided, which uses the device for external field reinforced and synergistic horizontal vacuum distillation purification of metal as described above, comprising the steps of: Placing the metal raw material in the raw material graphite boat and closing the quartz tube; Starting the vacuum system to reduce the pressure in the quartz tube to ≤5×10⁻ 4 Pa, and then starting the distillation heater for heating; Applying at least one external field through at least one of the electromagnetic field generator, the ultrasonic field generator and the microwave field generator; Raising the temperature of the heating zone to the target temperature at a rate of 5-20℃ / min, maintaining the temperature of the condensation zone to be lower than that of the evaporation zone by 200-800℃, trapping the high-vapor-pressure impurities after evaporation, and collecting the target metal vapor in the condensation zone.

[0015] Compared with the prior art, the device for synergistically purifying metal by horizontal vacuum distillation under external field reinforcement has the advantages that: through the multi-field synergistic reinforcement effect, the device breaks through the limitation of single temperature control, the mechanical vibration and macroscopic liquid flow of the melt caused by the ultrasonic field in the metal melt make the impurity distribution in the distillation system more uniform, which helps the impurities to be more uniformly distributed in the melt system and avoids the situation that the local concentration is too high or too low. In addition, the ultrasonic cavitation produces micro-bubbles and releases energy to promote the migration and evaporation of impurity atoms, thereby improving the distillation efficiency and purity. The electromagnetic field drives the directional migration of target impurities, accelerates the mass transfer of impurities in the metal melt, the microwave field selectively heats impurities to achieve targeted dissociation of impurities; reduces the viscosity of the melt; accelerates the migration of impurities to the gas / liquid interface; the microwave electric field improves the mobility of impurity ions, synergizes with the magnetic field to strengthen the directional migration effect, shortens the purification period, and improves the product purity. In addition, the horizontal vacuum distillation has a larger and more uniform gas-liquid contact interface, the metal melt forms a thin and uniform liquid film in the horizontal container, the gas and liquid are in full contact, and the uniform distribution of the gas and liquid significantly improves the gas-liquid mass transfer and separation effect; the horizontal distillation structure can effectively reduce the gas-liquid backmixing, the gas and liquid flow in a stable horizontal direction, and the impurities are difficult to return to the liquid phase after entering the gas phase, which is beneficial to the complete removal of impurities; the heating source can be uniformly distributed in the distillation container, so that the temperature field distribution of the metal melt and the steam in the horizontal direction is uniform, ensuring that the distillation is carried out at a stable temperature, and avoiding the incomplete removal of impurities caused by local overheating or overcooling. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 The device structure diagram of the device for synergistically purifying metal by horizontal vacuum distillation under external field reinforcement is shown in the figure. Figure 2 The structure diagram of the equidistant inclined baffle plate group of an embodiment is shown in the figure. Figure 3 The structure diagram of the non-equidistant vertical baffle plate group of an embodiment is shown in the figure. Figure 4 The structure diagram of the equidistant vertical baffle plate group of an embodiment is shown in the figure. Figure 5 The ultrasonic cavitation effect diagram of an embodiment is shown in the figure. Figure 6 The micro-morphology diagram of distilled indium of an embodiment is shown in the figure. Figure 7 The micro-morphology diagram of distilled selenium of an embodiment is shown in the figure. Figure 8 The micro-morphology diagram of distilled tellurium of an embodiment is shown in the figure. LEGEND: 1, horizontal vacuum distillation system; 2, vacuum system; 3, fractional condensation collection system; 4, external field enhanced distillation system; 11, quartz tube; 12, raw material graphite boat; 13, condensation collection boat; 14, steam transition tube; 15, distillation heater; 21, mechanical pump; 22, diffusion pump; 23, main vacuum pipeline; 24, auxiliary vacuum pipeline; 25, electronic vacuum gauge; 31, condensation heater I; 32, condensation heater II; 33, condensation heater III; 34, baffle group; 41, electromagnetic field generator; 42, ultrasonic field generator; 43, microwave field generator; 44, phase controller. DETAILED DESCRIPTION

[0017] In order to facilitate the understanding of the present application, the following will be a more comprehensive and detailed description of the present application in conjunction with the preferred embodiments and the accompanying drawings, but the protection scope of the present application is not limited to the following specific embodiments.

[0018] Unless otherwise defined, all the professional terms used in the following have the same meaning as generally understood by those skilled in the art. The professional terms used in this paper are only for the purpose of describing the specific embodiments and are not intended to limit the protection scope of the present application.

[0019] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present application can be purchased from the market or can be prepared by existing methods.

[0020] Please refer to Figures 1-8 The device for external field enhanced and horizontal vacuum distillation purification of metal in an embodiment mainly comprises: horizontal vacuum distillation system 1, vacuum system 2, fractional condensation collection system 3 and external field enhanced system 4. Specifically, the horizontal vacuum distillation system 1 comprises quartz tube 11, raw material graphite boat 12, condensation collection boat 13, distillation heater, steam transition tube 14 and distillation heater 15 arranged in the quartz tube 11.

[0021] Preferably, in an embodiment, the quartz tube 11 is a quartz tube, the quartz tube 11 is a cylindrical main body with a diameter Φ = 800 ~ 1200 mm, a length-diameter ratio of 10:1 ~ 20:1, a quartz tube 11 wall thickness δ = 8 ~ 15 mm, and a flange seal at both ends. The angle between the axis of the quartz tube 11 and the horizontal is ≤5°, preferably 0.5° ~ 2°. The raw material graphite boat 12, the condensation collection boat 13, the distillation heater 15 and the steam transition tube 14 are preferably made of high-purity graphite with ash content <5ppm; the distillation heater 15 uses resistance wire heating or electromagnetic heating, and the resistance wire and the electromagnetic induction coil are arranged alternately, and the resistance heating is preferred at a working temperature of 1000℃, and the electromagnetic heating is preferred at a working temperature above 1000℃.

[0022] The external field strengthening system 4 includes at least one of an electromagnetic field generator 41, an ultrasonic field generator 42 and a microwave field generator 43 arranged on the outer wall of the quartz tube 11. The ultrasonic field induces mechanical vibration and macroscopic liquid flow in the metal melt, which makes the impurities in the distillation system more evenly distributed, and helps to make the impurities more evenly distributed in the melt system, avoiding the occurrence of local concentration too high or too low. In addition, ultrasonic cavitation produces microbubbles and releases energy to promote impurity atom migration and evaporation, thereby improving distillation efficiency and purity. The electromagnetic field drives the directional migration of target impurities, accelerating the mass transfer of impurities in the metal melt. The microwave field selectively heats impurities such as sulfides (S / Se), arsenides (As) and other impurities, breaks their chemical bonds (such as S-Se bonds) at a temperature lower than the melting point of selenium, and realizes targeted dissociation of impurities; reduces the melt viscosity; the microwave reduces the viscosity of the selenium melt, accelerating the migration of impurities to the gas / liquid interface.

[0023] Specifically, in an embodiment, the electromagnetic generator 41 includes a solenoid coil arranged coaxially around the quartz tube, with a magnetic field strength of 0.1-5 T and an electromagnetic frequency of 1-100 kHz. The ultrasonic field generator 42 is a piezoelectric ceramic transducer array embedded in the bottom of the quartz tube, with an ultrasonic frequency of 20-40 kHz and an acoustic intensity of ≥10 W / cm². The microwave field generator 43 is arranged at the waveguide port at the top of the furnace for vertical radiation of the metal raw material in the graphite boat, with a microwave frequency of 2.45 GHz±50 MHz and a power of 1-10 kW. The fractional condensation collection system 3 includes multiple condensation heaters arranged in the quartz tube.

[0024] Specifically, in an embodiment, the fractional condensation collection system 3 includes condensation heater I 31, condensation heater II 32, condensation heater III 33 and condensation collection boat 13. The above-mentioned heaters are all resistance heaters, including resistance wires arranged coaxially around the quartz tube 11, and each heater is independently controlled. The condensation collection boat 13 is provided with 5-8 baffle groups 34, and the material of the baffle group is preferably high-purity graphite with ash content <5 ppm. The adjacent baffle groups 34 can be arranged at equal intervals or non-equal intervals according to actual needs, and are preferably arranged at exponentially decaying intervals. For metal raw materials with high impurity content, non-equal intervals are adopted, and the intervals are exponentially decaying, which is conducive to impurity separation. For example, the interval between the multiple baffle groups decreases by 10%-50% along the steam flow direction. The baffle angle adjustment range is 30-90°, and the residence time of steam in the distillation and condensation area is controlled by adjusting the interval and inclination angle of the baffle according to the nature and content of the impurities, thereby improving the efficiency of impurity separation.

[0025] Specifically, the pitch and the inclination angle of the baffle are selected according to the condensation characteristics of the main metal and the types of impurities. Non-equidistant baffles are generally used for the purification of 2N crude metal, the initial pitch of the vapor flow into the distillation section is increased to lengthen the length of the impurity condensate, and the impurity metal is effectively separated, usually requiring 3-4 baffles. For the deep purification of 4N and above metal, equidistant baffles can be used, and high-melting-point metal impurities are condensed and enriched to the first 2 baffles, the middle baffles are mainly used for the enrichment of the main metal, and the tail baffles are used for the enrichment of low-melting-point metals. For example, in an embodiment, high-melting-point impurities such as Cu, Fe, and Ni are condensed and enriched at the inlet of the condensation zone, and impurities such as Se, Te, Mg, and Zn are condensed and enriched at the outlet of the condensation zone.

[0026] The inclination angle of the baffle is 30°-90°, which is used in cooperation with the condensation heater I 31, the condensation heater II 32, and the condensation heater III 33. The angle of the baffle is determined according to the characteristics of the main metal and the impurity metal. For main metals that are easy to condense (such as Se and Te), the inclination angle is 30°-60°, and this process can be coordinated with the three-stage condensation heater to control the temperature and adjust the condensation zone of the main metal. In addition, baffles with different angles can adjust the flow rate of the vapor flow through the condensation zone, avoiding the situation where the vapor flow cannot be condensed due to too fast a flow rate or the main metal is condensed in large quantities at the front end, blocking the vapor passage at the condensation site. Controlling the vapor flow rate to reduce the backmixing of vapor rich in impurities and pure metal vapor is more conducive to the separation of impurities.

[0027] The vacuum system 2 includes a mechanical pump 21 and a diffusion pump 22 connected by a vacuum pipeline. The diffusion pump 22 is connected to the quartz tube 11 and is used to control the vacuum degree in the quartz tube 11. Specifically, in an embodiment, the diffusion pump 22 is connected to the quartz tube 11 through a main vacuum pipeline 23, and an electronic vacuum gauge 25 is arranged on the main vacuum pipeline 23. The mechanical pump 21 and the diffusion pump 22 are connected by a secondary vacuum pipeline 24. The mechanical pump has a limit vacuum of 10 -2 Pa, and the diffusion pump has a limit vacuum of ≤5×10 ⁻4 Pa.

[0028] Preferably, in an embodiment, a phase controller 44 is further included for real-time adjustment of the phase difference between the electromagnetic field and the ultrasonic field. The phase controller 44 adjusts the phase difference between the electromagnetic field and the ultrasonic field in real time to be π / 2-π, and the phase difference adjustment accuracy is ±0.1 rad, which plays a role in suppressing field interference.

[0029] The external field enhanced metal purification method of an embodiment adopts the above-mentioned device for external field enhanced and horizontal vacuum distillation purification of metal, and includes the following steps: S10, placing the metal raw material in the raw material graphite boat 12 and closing the quartz tube 11; Specifically, the raw material graphite boat 12, steam transition pipe 14 and condensation collection boat 13 are ultrasonically cleaned, then scrubbed with high-purity alcohol multiple times and vacuum dried. Then the raw material of the powder or block crude metal is loaded into the raw material graphite boat 12, the loading amount is 70-80% of the graphite boat, sequentially placed from one end of the quartz tube 11 and connected, the flange is closed and sealed.

[0030] S20, the vacuum system 2 is started to reduce the pressure in the quartz tube 11 to ≤5×10⁻ 4 Pa, and the distillation heater 15 is started to heat; Specifically, the mechanical pump 21 is started to reduce the vacuum degree in the quartz tube 11 to 10 -1 Pa, the diffusion pump 22 is started, and the vacuum degree is reduced to 10 -3 Pa, and the leakage rate is maintained to be <1×10⁻ 9 Pa·m³ / s. Then the temperature control program of the distillation heater 15 is started, and the temperature is raised to the melting point at 10 ℃ / min, and in this process, the main metal is gradually melted.

[0031] S30, at least one external field is applied by at least one of the electromagnetic field generator 41, the ultrasonic field generator 42 and the microwave field generator 43; Specifically, the microwave field pulse width modulation duty cycle is 70%, at this time, the internal melt is rapidly heated, the thermal boundary layer is broken, and the microwave heating causes the internal melt to instantaneously generate a micro-zone melting point, decomposes the impurity compounds into elemental form. After reaching the target distillation temperature, the electromagnetic field and the ultrasonic field are applied synchronously, and the phase difference is set to π / 4, π / 2 or 2π / 3. The cavitation collapse and fragmentation of the impurity inclusions generated by the ultrasonic field, and the Lorentz force generated by the electromagnetic field drives the directional migration of the impurities from the internal melt, and enhances the dynamics of its evaporation. In other embodiments, only one or three external fields can be applied.

[0032] S40, the heating zone is maintained to be raised to the target temperature at 5-20 ℃ / min, and the condensation zone temperature is lower than the evaporation zone by 200-800 ℃; after the high-vapor-pressure impurities are evaporated, they are intercepted, and the target metal vapor is collected in the condensation zone.

[0033] Specifically, the main metal vapor directionally migrates to the condensation zone under the action of the gas flow, and is dynamically gradient condensed by the baffle group 34. Due to the difference in physical and chemical properties between the impurities and the main metal, there is a difference in the relative saturated vapor pressure of the impurities and the main metal. Generally, the low-saturated-vapor-pressure impurities are intercepted by the first to second-stage baffle groups, and the high-saturated-vapor-pressure impurities are enriched in the tail baffle. The main metal is condensed and deposited on the middle baffle in large quantities, with a purity of >99.999%, and finally the high-purity metal after distillation and purification is scraped off by using a titanium alloy tool.

[0034] Specifically, the baffle group 34 adopts equidistant design or non-equidistant design to meet d n+1 / dn = 0.85 ± 0.03.

[0035] Impurity interception efficiency model:

[0036] wherein, N = baffle stage 3-8, r p R = radius of baffle, p p ρ = density of impurity, v t V = impurity settling velocity, β = empirical parameter for different impurities.

[0037] Multi-field coupling impurity removal formulaic expression:

[0038] wherein, = dimensionless synergistic effect coefficient, the larger the value, the higher the impurity removal rate; (m -1 ·s) = material-specific constant: related to melt viscosity, impurity size; F L (N·C -1 ) = Lorentz force strength: F L = q(v x B), driving impurity ion migration; v d (m / s) impurity ion migration velocity: directly related to migration distance; (t) effective magnetic field action time: related to pulse width / frequency; K cav Dimensionless cavitation effect coefficient: characterizes ultrasonic energy conversion rate; P A (Pa) sound pressure amplitude; ρc (kg·m -2 ·s -1 ) acoustic impedance: melt density x sound speed; (rad / s) ultrasonic angular frequency; (F / m) microwave dielectric loss factor; Dimensionless, loss tangent; (s -1 ) microwave power loading frequency; (rad) field phase difference; Dimensionless, phase synergistic factor.

[0039] Example 1: The device and method of the present application are used for purifying fine indium.

[0040] Put 450 g of fine indium particles with a purity of 99.99% in the raw material graphite boat 12, and sequentially load the condensation collection boat 13, the vapor transition tube 14 and the raw material graphite boat 12 into the quartz tube 11. After sealing the flange, start the mechanical pump 21 to reduce the vacuum degree in the furnace cavity of the quartz tube 11 to below 10 Pa, and start the diffusion pump 22 to reduce the vacuum degree in the furnace cavity to below 10 Pa. -3 Start the distillation heater 15, and use electromagnetic heating to increase the temperature to 900°C at a rate of 15°C / min. Start the microwave field at 10.0 kW and 3.05 GHz, and the internal micro-zone temperature of the melt instantaneously increases, decomposing impurity compounds such as indium compounds (As2In, Cu2In, PbIn3, Cu2S, PbS, As2S3), and the melt evaporates to form indium vapor. After the temperature reaches the predetermined distillation temperature of 1100°C, simultaneously start the alternating electromagnetic field at 1.0 T and 50 kHz and the ultrasonic field at 40 kHz and 25 W / cm 2 , and the Lorentz force generated by the electromagnetic field drives the Tl + to move in the opposite direction of the condensation zone, and the ultrasonic field inhibits the formation of compounds between the indium melt surface and impurity ions, and the phase difference is controlled to π / 4 to inhibit interference between the fields. A 6-stage baffle group is selected, and an equidistant design d0=100 mm is used, and the baffle angle is adjusted to 45 degrees. The holding time is 180 min, and after the distillation is completed, the heating program and the external field program are turned off, the quartz tube 11 furnace cavity is naturally cooled to room temperature, 5N high-purity argon is introduced to restore the normal pressure, the flange is opened, and the raw material graphite boat 12, the vapor transition tube 14 and the condensation collection boat 13 are sequentially taken out, the condensation products at the baffle positions are scraped off using titanium alloy tools, and samples are taken for analysis and detection using ICP-MS. The high-boiling-point impurities such as Sn and Fe are condensed and trapped in the first-stage baffles 1-2, the medium-boiling-point impurities such as Cd, Pb, Tl and Zn are condensed and trapped in the middle-stage baffles 3-4, and the high-purity indium vapor is condensed at the end-stage condensation baffles 5-6 with a temperature of 200±5°C. The product purity and the impurity content meet the 5N high-purity indium industry standard YS / T 264-2012. The removal rate of the impurity Sn reaches 99.3%, and the oxygen impurity content is <5 ppm, which is an increase of 20.8% compared to the removal rate of 78.5% of the traditional horizontal distillation in Comparative Example 1, and a decrease of 94% compared to the O content of 85 ppm of the product of the traditional horizontal distillation. The ultrasonic field cavitation effect breaks the impurity inclusions, and the equidistant baffle group increases the Pb vapor trapping rate from 82% to 91.54%. The removal rates of the impurities Cd, Pb, Tl, Zn and Sn are 90.8%, 91.54%, 87.25%, 98.23% and 99.3%, respectively. The application of electromagnetic heating + microwave field and electromagnetic field external field compared to single resistance heating reduces the time required for heating to complete melting of the raw material from 55 min to 22 min. Figure 6 The electron microscope micro-morphology of the high-purity indium is shown in FIG. 1, and regular crystal growth is obvious. Table 1 shows the impurity detection results of the high-purity indium using ICP-MS.

[0041] Table 1: Impurity content analysis results of distillation indium product

[0042] Example 2: The device and method of the present application are used for purifying crude selenium.

[0043] 500g of crude selenium powder with a purity of 99.5% was placed in the raw material graphite boat 12, and the condensation collection boat 13, the vapor transition tube 14 and the raw material graphite boat 12 were sequentially loaded into the quartz tube 11. After sealing the flange, the mechanical pump 21 was started to reduce the vacuum degree in the furnace cavity of the quartz tube 11 to below 10 Pa, and the diffusion pump 22 was started to reduce the vacuum degree in the furnace cavity of the quartz tube 11 to below 10 Pa. -3 The distillation heater 15 was started, and resistance heating was used to raise the temperature to 150°C at a rate of 8°C / min. The microwave field was started at 4.0kW, 2.45GHz, the internal micro-zone temperature of the melt was instantaneously raised, impurity compounds such as Fe2Se, Cu2Se, As2Se3, etc. were decomposed, and the melt evaporated to form selenium vapor. After the temperature reached the predetermined distillation temperature of 280°C, the electromagnetic field 1.0T, 50kHZ and the ultrasonic field 28kHZ, 15W / cm 2 were simultaneously started. The Lorentz force generated by the electromagnetic field pushed the S 2- ions to the surface layer of the melt, the cavitation effect generated by the ultrasonic field broke the impurity inclusions, and the phase difference control was π / 2 to precisely suppress the interference between the fields. The 7-stage baffle group was designed with a non-equidistant design d n+1 / d n =0.85, and an angle of 90 degrees. The holding time was 120 min, after the distillation was completed, the heating program and the external field program were turned off, the furnace cavity was naturally cooled to room temperature, 5N high-purity argon was introduced to restore the normal pressure, the flange was opened, and the raw material graphite boat 12, the vapor transition tube 14 and the condensation collection boat 13 were sequentially taken out. Titanium alloy tools were used to scrape the condensation products at the baffle positions, and samples were taken for analysis and detection by ICP-MS. S, As, Hg, Te, etc. were intercepted at the 6th-7th stage baffles, Cu, Fe, Ni, etc. were intercepted at the 1st stage baffle, and selenium vapor was condensed in large quantities to the 2nd-5th stage baffles. The product purity and impurity content met the 5N high-purity selenium industry standard YS / T 816-2012. The removal rate of impurity Te reached 90.8%, which was 15.6% higher than the 75.2% without external field strengthening distillation. The removal rates of high-boiling-point impurities Cu, Fe, Ni, etc. were >99.9%, which was 5.2% higher than the 94.7% without external field strengthening. The removal rate of impurity Hg reached 99.3%, which was 33.9% higher than the 65.4% without external field strengthening distillation. Figure 7 The electron microscope micro-morphology of high-purity selenium is shown in Figure 2, which presents obvious cluster growth. Table 2 shows the impurity detection results of high-purity selenium by ICP-MS.

[0044] Table 2: Results of impurity content analysis of distilled selenium products

[0045] Example 3: The apparatus and method of this application are used to purify crude tellurium.

[0046] 400g of lumpy crude tellurium with a purity of 99.81% was placed in the raw material graphite boat 12. The condensation collection boat 13, the steam transfer pipe 14, and the raw material graphite boat 12 were then sequentially loaded into the quartz tube 11. After sealing the flange, the mechanical pump 21 was started to reduce the vacuum level inside the furnace chamber of the quartz tube 11 to below 10 Pa, and the diffusion pump 22 was started to reduce the vacuum level inside the furnace chamber to 10 Pa. -3 Pa. The distillation heater 15 is started, using resistance heating to raise the temperature to 400℃ at a rate of 8℃ / min. A microwave field of 8.0kW, 2.5GHz is activated, creating a micro-region of high temperature within the melt, decomposing impurity compounds such as silver telluride (e.g., Ag₂Te, As₂Te₃, PbTe, Bi₂Te₃, Cu₂Te, etc.), and the melt evaporates to form tellurium vapor. After the temperature reaches the predetermined distillation temperature of 500℃, an electromagnetic field of 2.4T, 80kHz and an ultrasonic field of 35kHz, 22W / cm² are simultaneously activated. 2 The Lorentz force generated by the electromagnetic field pushes Cu 2+ Ions migrate along the vapor flow, and the cavitation effect generated by the ultrasonic field breaks up CuTe inclusions. The phase difference is controlled to π / 2 to suppress inter-field interference. The 7-stage baffle assembly adopts a non-equidistant design. n+1 / d n =0.85, angle 60 degrees. Holding time 180 min. After distillation, the heating and external programs are turned off, and the furnace cavity is allowed to cool naturally to room temperature. 5N high-purity argon gas is introduced to restore atmospheric pressure. The flange is opened, and the raw material graphite boat 12, steam transition pipe 14, and condensation collection boat 13 are removed sequentially. The condensed products at each baffle plate location are scraped using titanium alloy tools, and samples are taken for ICP-MS analysis. The removal rates of impurities Se, Fe, Cu, Ni, S, and Na are 87.12%, 95.23%, 98.65%, 99.81%, 84.95%, and 87.54%, respectively. S, As, and Se are retained in the 6th and 7th stage baffle plates, while Cu, Fe, and Ni are retained in the 1st stage baffle plate. A large amount of tellurium vapor is condensed to the 2nd to 5th stage baffle plates. The product purity and impurity content meet the 5N high-purity tellurium industry standard YS / T 817-2012. The removal rate of impurity Se was increased by 24.97% compared to 62.15% without external field enhancement distillation, the removal rate of impurity Cu was increased by 11.5% compared to 87.15% without external field enhancement distillation, and the removal rate of impurity Na was increased by 8.55% compared to 76.4% without external field enhancement distillation. Figure 8The electron microscope micro-morphology of the high-purity tellurium shows obvious columnar crystal growth. Table 3 shows the impurity detection results of the high-purity tellurium by ICP-MS.

[0047] Table 3: Analysis results of impurity content of distillation tellurium product

[0048] Comparative Example 1 Take the same indium particles 450g as in Example 1. First, the material is loaded into a traditional vertical quartz distillation furnace with a single-end condenser collector, the mechanical pump and diffusion pump are started to vacuumize the distillation furnace, the heating program is started to raise the melting furnace from room temperature 25℃ to 1100℃ at a temperature rise rate of 10℃, and vacuum distillation is carried out at a distillation temperature of 1100℃, a vacuum degree of 10 -3 Pa, and a holding time of 180 min. After completion, the graphite crucible is taken out, and the distillation product is taken out in a dust-free environment. Table 4 shows the impurity content analysis results of the distillation indium product, the product purity is 99.998%, and the impurity contents of Cd, Sn, Zn, Fe are 0.65 ppm, 0.55 ppm, 1.2 ppm, 1.8 ppm and 0.9 ppm respectively, which does not meet the 5N high-purity indium standard. The resistance wire is heated to 1100℃ for 120 min, and the purification cycle is 28 h for repeated distillation for 3 times, and the indium recovery rate is 82.5%.

[0049] Table 4: Analysis results of impurity content of distillation indium product

[0050] Comparative Example 2 Take the same selenium powder 500g as in Example 2. The material is loaded into a traditional vertical quartz distillation furnace, the vacuum pump and diffusion pump are started to vacuumize the vacuum distillation furnace, the heating program is started to raise the melting furnace from room temperature 25℃ to 280℃ at a temperature rise rate of 8℃, and vacuum distillation is carried out at a distillation temperature of 280℃, a vacuum degree of 10 -3 Pa, and a holding time of 120 min. After completion, the graphite crucible is taken out, and the distillation product is taken out in a dust-free environment. Table 5 shows the impurity content analysis results of the distillation selenium product, the product purity is 99.9991%, and the impurity contents of Mg, Ag, Fe, Ni, Cu, Te, Ti, Pb are 0.57 ppm, 0.35 ppm, 1.39 ppm, 0.8 ppm, 0.61 ppm, 1.33 ppm, 0.83 ppm, 0.62 ppm respectively, which does not meet the 5N high-purity selenium standard.

[0051] Table 5: Analysis results of impurity content of distillation selenium product

[0052] Comparative Example 3: The same tellurium ingot 400 g as in Example 3 was taken. The tellurium ingot raw material was first crushed into chunks, and then the material was loaded into the horizontal vacuum distillation furnace of the present application, the vacuum pump and the diffusion pump were started to perform vacuumizing treatment on the horizontal vacuum distillation furnace, the heating program was started to raise the temperature of the melting furnace from room temperature 25 °C to 500 °C at a temperature raising rate of 5 °C, the distillation temperature was set to 500 °C, the vacuum degree was set to 10 -3 The vacuum distillation was performed under the conditions of a pressure of 10 Pa and a holding time of 180 min, no external field was applied during the distillation process, the distillation was repeated for 3 times, after the distillation was completed, the graphite crucible was taken out, and the distillation product was taken out in a dust-free environment. Table 6 is the analysis result of the impurity content of the distillation tellurium product, the product purity is 99.998%, and the impurity contents of Mg, Al, Ag, Ni, Na, Ca, Mn, Zn and Se are 1.18 ppm, 0.68 ppm, 0.5 ppm, 1.05 ppm, 0.85 ppm, 0.62 ppm, 0.61 ppm, 0.63 ppm and 6.23 ppm respectively, which does not meet the 5N high purity tellurium standard.

[0053] Table 6: Analysis result of impurity content of distillation tellurium product

[0054] The above is only a preferred embodiment of the present application, it should be noted that the present application is not limited to the above-mentioned embodiment, for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should also be considered as the protection scope of the present application.

Claims

1. A device for field-enhanced synergistic horizontal vacuum distillation purification of metals, characterized in that, It comprises: A horizontal vacuum distillation system, including a quartz tube, a raw material graphite boat, a distillation heater, a condensation collection boat and a vapor transition tube arranged in the quartz tube; An external field strengthening system, including at least one of an electromagnetic field generator, an ultrasonic field generator and a microwave field generator arranged on the outer wall of the quartz tube; A staged condensation collection system, including a plurality of condensation heaters arranged in the quartz tube; A vacuum system, including a mechanical pump and a diffusion pump connected by a vacuum pipeline, wherein the diffusion pump is connected with the quartz tube for controlling the vacuum degree in the quartz tube.

2. The device for external field enhanced synergic horizontal vacuum distillation purification of metals according to claim 1, characterized in that, It also includes a phase controller for adjusting the phase difference between the electromagnetic field and the ultrasonic field in real time.

3. The device for external field enhanced synergic horizontal vacuum distillation purification of metals according to claim 1, characterized in that, The electromagnetic generator includes a solenoid coil arranged coaxially around the quartz tube, with a magnetic field strength of 0.1-5 T and an electromagnetic frequency of 1-100 kHz.

4. The device for external field enhanced synergic horizontal vacuum distillation purification of metals according to claim 1, characterized in that, The ultrasonic field generator is a piezoelectric ceramic transducer array embedded in the bottom of the quartz tube, with an ultrasonic frequency of 20-40 kHz and a sound intensity of ≥10 W / cm².

5. The device for external field enhanced synergic horizontal vacuum distillation purification of metals according to claim 1, characterized in that, The microwave field generator is arranged at the waveguide port at the top of the quartz tube for vertical radiation of the metal raw material in the raw material graphite boat, with a microwave frequency of 2.45 GHz±50 MHz and a power of 1-10 kW.

6. The device for external field strengthened synergistic horizontal vacuum distillation purification of metals according to claim 1, characterized in that, A plurality of baffle plates are arranged in the condensation collection boat.

7. The device for field-enhanced synergistic horizontal vacuum distillation purification of metals according to claim 6, characterized in that, The angle adjustment range of a single baffle plate of the baffle plate group is 30-90°.

8. The device for field-enhanced synergistic horizontal vacuum distillation purification of metals according to claim 6, characterized in that, The inter-plate spacing of the multi-stage baffle plate group decreases by 10%-50% along the vapor flow direction.

9. The device for external field strengthened synergistic horizontal vacuum distillation purification of metals according to claim 1, characterized in that, The distillation heater includes alternatingly arranged resistance wires and electromagnetic induction coils, using resistance heating when the working temperature is lower than 1000℃ and using electromagnetic heating when the working temperature is higher than 1000℃.

10. A method for external field strengthened metal purification, using the device for external field strengthened and cooperated horizontal vacuum distillation purification of metal according to any one of claims 1-9, comprising the steps of: Placing the metal raw material in the raw material graphite boat and closing the quartz tube; The vacuum system is started to reduce the pressure in the quartz tube to < 5 x 10⁻ 4 Pa after which the distillation heater is started to heat up; Applying at least one external field through at least one of the electromagnetic field generator, the ultrasonic field generator and the microwave field generator; Maintaining the heating zone to rise to the target temperature at a rate of 5-20℃ / min, maintaining the condensation zone temperature to be lower than the evaporation zone by 200-800℃, and trapping the high vapor pressure impurities after evaporation, and collecting the target metal vapor in the condensation zone.

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