Gas-phase magnesium purification method and device based on pure iron filter material
阅读说明：本技术 一种基于纯铁滤材的气相镁纯化的方法与装置 (Gas-phase magnesium purification method and device based on pure iron filter material ) 是由 单智伟 杨博 刘博宇 毛路遥 王安 于 2019-11-27 设计创作，主要内容包括：本发明提供一种基于纯铁滤材的气相镁纯化的方法,所述方法采用纯铁滤材对镁蒸气进行过滤。纯铁一方面不会与镁蒸气进行反应,不会给体系带来新的杂质；另一方面,镁蒸气中的杂质Al、Mn与铁具有特殊的亲和性,能够与铁形成稳定的固溶体；同时纯铁能够作为镁蒸气中某些杂质形核的位点,降低形核能垒,使某些杂质提前沉积,脱除杂质。本发明提供的方法能够应用于工业化大规模的气相镁纯化中,通过提高温度来成数量级的提高镁纯化的生产效率,使镁原料中杂质Mn含量下降至10ppm以下、Al含量下降至10ppm以下、Ca含量下降至20ppm以下,同时可去除F、Cl、S等非金属杂质元素,得到纯度在99.99％以上的镁。(The invention provides a gas-phase magnesium purification method based on a pure iron filter material. On one hand, pure iron does not react with magnesium vapor, and does not bring new impurities to the system; on the other hand, impurities Al and Mn in the magnesium vapor have special affinity with iron and can form a stable solid solution with the iron; meanwhile, pure iron can be used as the nucleation site of some impurities in magnesium vapor, so that the nucleation energy barrier is reduced, some impurities are deposited in advance, and the impurities are removed. The method provided by the invention can be applied to large-scale industrialized gas-phase magnesium purification, improves the production efficiency of magnesium purification by increasing the temperature in a magnitude order, reduces the content of impurities Mn in the magnesium raw material to below 10ppm, the content of Al in the magnesium raw material to below 10ppm and the content of Ca in the magnesium raw material to below 20ppm, and can remove non-metallic impurity elements such as F, Cl, S and the like to obtain magnesium with the purity of above 99.99 percent.)
1. A method for purifying gas-phase magnesium based on a pure iron filter material is characterized by comprising the following steps:
(1) placing a magnesium raw material in a reaction zone in a sealed crucible, and vacuumizing the interior of the crucible;
(2) heating the magnesium raw material by a heating mechanism until magnesium steam is generated, and condensing the magnesium steam on a crystallizer of which the crucible is far away from the reaction zone through a pure iron filter material to obtain high-purity magnesium.
2. The method for purifying magnesium in a gas phase based on a pure iron filter material as claimed in claim 1, wherein in the step (1), the vacuum degree in the crucible is below 20 Pa.
3. The method for purifying magnesium in gas phase based on pure iron filter material as claimed in claim 1, wherein the heating temperature in step (2) is 700-1300 ℃.
4. The method for purifying gas-phase magnesium based on the pure iron filter material as claimed in claim 3, wherein the heating in the step (2) is performed in three stages, wherein the first stage heats the reaction zone of the crucible provided with the magnesium raw material at the temperature of 700-1300 ℃; the second section and the third section sequentially heat an impurity condensation zone provided with a pure iron filter material in the crucible, the setting temperature of the second section is 700-plus-1300 ℃, and the setting temperature of the third section is 700-plus-800 ℃.
5. The method for purifying magnesium in gas phase based on pure iron filter material as claimed in claim 4, wherein in the step (2), the pure iron filter material is arranged in an impurity condensation zone in the crucible, and the working temperature of the pure iron filter material is 700-.
6. A gas-phase magnesium purification device containing a pure iron filter material is characterized by comprising an electric furnace body, a crucible, a heating mechanism, a thermocouple and a vacuum mechanism;
the crucible comprises a reaction zone, an impurity condensation zone and a crystallization zone which are arranged in sequence,
the reaction zone is provided with a hopper,
the impurity condensing zone is provided with a filtering component,
the filter component is provided with a filter material which is made of pure iron,
the crystallization zone is provided with a crystallizer;
the vacuum mechanism is arranged in the electric furnace body, and the crucible is arranged in the vacuum mechanism;
the thermocouple is arranged on the outer wall of the crucible;
the heating mechanism is arranged in the electric furnace body to heat the crucible.
7. The apparatus for purifying magnesium in a gaseous phase comprising a pure iron filter according to claim 6, wherein the filter is one of metal foam iron, iron fiber or iron microsphere, and the purity of the filter is 99.2% or more.
8. The apparatus for purifying magnesium in gas phase comprising a pure iron filter material as claimed in claim 7, wherein when the filter material is a metal foam iron, the pore size of the metal foam iron is below 30ppi, when the filter material is an iron fiber, the pore size of the iron fiber is 100-400 mesh, and when the filter material is an iron microsphere, the particle size of the iron microsphere is 45-5000 μm.
9. The apparatus for purifying magnesium in a gaseous phase comprising a pure iron filter according to claim 6, wherein said heating means comprises a first heating element, a second heating element and a third heating element; the first heating assembly heats a reaction zone of the crucible; the second heating assembly and the third heating assembly heat an impurity condensing region of the crucible.
10. The apparatus for purifying magnesium in a gas phase comprising a pure iron filter material according to claim 6, wherein the vacuum mechanism comprises a vacuum chamber, a water-cooled flange, an end cap and an evacuation assembly; the vacuum cabin body is arranged inside the electric furnace body; the water-cooling flanges are arranged at two ends of the vacuum cabin body; the end cover is arranged at the end part of the water-cooling flange far away from the vacuum cabin body; the vacuumizing assembly can vacuumize the interior of the vacuum cabin; the crucible is arranged inside the vacuum cabin.
Technical Field
The invention belongs to the technical field of magnesium metal purification, and particularly relates to a method and a device for purifying gas-phase magnesium based on a pure iron filter material.
Background
Magnesium and magnesium alloys are the lightest metallic structural materials, with densities of approximately two thirds for aluminum alloys and one fifth for steel. Therefore, one of the important applications of magnesium alloys is energy saving and weight reduction in the fields of automobile industry, rail transit, and the like. In addition, the magnesium alloy also has the advantages of good electromagnetic shielding performance, excellent biocompatibility and the like, and has bright application prospect in more functional fields. Currently, the magnesium purification field has aeipathia diseases such as low overall purity (only 99.90%), many types of impurity elements (mainly containing Mn, Al, Ca, Si, Fe, Ni and the like), large content fluctuation and the like. These maladies severely degrade the performance of the magnesium alloy, which in turn makes its practical application far less than desired.
There are two common methods for purifying magnesium metal: flux refining and vacuum distillation. The former has the advantage of realizing the large-scale purification of the crude magnesium and is the main method for purifying the industrial crude magnesium at present. The main flux used in flux refining method is only partial halide of alkali metal and alkaline earth metal, and the flux used most commonly in factory is MgCl2、KCl、CaF2And the like. The impurity removal mechanism of the refining agent comprises two aspects: firstly, the refining agent is used for carrying out oxide inclusion (MgO and SiO)2Etc.) to separate oxide inclusions from the magnesium melt by standing precipitation; secondly, by reacting the active metal impurities, e.g. K, Na, with MgCl in the melt2To remove metal impurities more active than magnesium. As the refining agent does not react with the impurity elements such as Mn, Al, Fe, Ni, Ca and the like of the reduced magnesium ingot in principle, the magnesium with the purity of more than 99.95 percent, in particular the standard of the national standard Mg9995A and above is difficult to produce. In addition, non-metallic impurity elements such as F, Cl, and S are often introduced into the refining flux, and the performance of the raw magnesium is also affected when the content of these impurity elements exceeds a certain threshold.
The vacuum distillation method has a long history, and the principle is that Mg is evaporated under proper temperature and pressure by utilizing the characteristic that the saturated vapor pressure difference between Mg and most impurity elements is large, and main impurities are remained in a melt, so that the separation of magnesium and the impurities is realized. The vacuum distillation method has the advantage that the ultrahigh-purity magnesium with the purity of 99.9999 percent (not counting the Zn content) can be prepared. However, in order to obtain higher purity, the distillation method is generally carried out under vacuum condition at an evaporation temperature close to the melting point of Mg (650- & gt 700 ℃), so that the preparation efficiency is low; the magnesium crystals in different temperature zones have different purities, and generally only the magnesium crystals at proper temperature are high-purity magnesium, so that the yield of the high-purity magnesium is low; to obtain ultra-high purity magnesium (99.999% -99.9999%), multiple distillations are required, and therefore the cost is high. For the above reasons, the vacuum distillation method cannot satisfy the demand for industrial mass production.
In addition, the method for purifying magnesium in the prior art also adopts a vapor deposition method of removing impurities with the aid of a filter material, but the common filter material adopts stainless steel fibers or a method of combining the stainless steel fibers and copper fibers, and the stainless steel is not suitable for the working condition of overhigh vapor pressure of magnesium and is suitable for the working condition of low-temperature sublimation with lower heating temperature, so that the magnesium purification efficiency is low, and the yield of high-purity magnesium is extremely low.
Disclosure of Invention
In order to solve the technical problems, the invention provides a gas-phase magnesium purification method and a gas-phase magnesium purification device based on a pure iron filter material.
The invention aims to provide a method for purifying gas-phase magnesium based on a pure iron filter material.
Another object of the present invention is to provide an apparatus for carrying out the above magnesium purification method.
The invention provides a gas-phase magnesium purification method based on a pure iron filter material, which comprises the following steps:
(1) placing a magnesium raw material in a reaction zone in a sealed crucible, and vacuumizing the interior of the crucible;
(2) heating the magnesium raw material by a heating mechanism until magnesium steam is generated, and condensing the magnesium steam on a crystallizer of which the crucible is far away from the reaction zone through a pure iron filter material to obtain high-purity magnesium.
The trace elements have great influence on the corrosion resistance of magnesium and magnesium alloy, iron (Fe) is a poisoning agent for workers to deteriorate the corrosion resistance of the magnesium alloy, the corrosion tolerance limit of iron in magnesium is 170ppm, namely the corrosion rate of pure magnesium with the content of iron exceeding 170ppm is increased by orders of magnitude; and after full heat treatment, the corrosion tolerance limit of iron in the pure magnesium is only 5 ppm. In the conventional concept, the magnesium purification process avoids the contact with the iron container and the iron element as much as possible. The invention breaks through the traditional thinking, and thermodynamic calculation shows that the vapor pressure of the pure iron is extremely low, so that the pure iron can not react with magnesium vapor when the magnesium is kept as magnesium vapor and passes through the pure iron filter material under the vacuum condition, and new impurities can not be brought to the system. From the magnesium-iron phase diagram, no intermediate metal is formed between magnesium and iron, and the solid solubility is extremely low, so that pure magnesium and pure iron are completely incompatible, magnesium vapor cannot be condensed due to the action of iron when passing through the pure iron filter material at high temperature, and metal magnesium cannot be lost. In addition, the pure iron has special affinity with Al and Mn in the magnesium vapor and can form stable solid solution to remove the solid solution, and the pure iron can be used as a nucleation site of certain impurities in the magnesium vapor to reduce the nucleation energy barrier and enable the certain impurities to be deposited in advance, so that part of the impurities in the magnesium vapor are removed.
Preferably, in the step (1), the degree of vacuum inside the crucible is 20Pa or less. The vacuum degree in the crucible provided by the invention is below 20Pa, and the efficiency of purifying magnesium can be ensured to be improved.
Preferably, in the step (2), the heating temperature is 700-.
The melting range of the magnesium raw material containing trace impurities is 650-700 ℃, the temperature in the crucible is set to be 700-1300 ℃ under the vacuum degree below 20Pa, the magnesium raw material containing impurities can be changed into magnesium vapor, iron as a filter material cannot enter a magnesium vapor system, after magnesium passes through a pure iron filter material, the impurities in the magnesium vapor can be well combined with the pure iron filter material, the impurities can obtain corresponding attachment points on the pure iron filter material, the impurities are remained in the pure iron filter material, the magnesium vapor further rises to a crystallization area, and the magnesium vapor is condensed on a crystallizer to obtain high-purity magnesium.
Further preferably, the heating temperature is 800-. When the temperature in the system is increased within a certain range, the evaporation rate of magnesium is exponentially increased, so that the production efficiency can be improved.
Preferably, in the step (2), the heating is performed in three sections, wherein the first section heats the reaction zone of the crucible provided with the magnesium raw material, and the temperature is 700-1300 ℃; the second section and the third section sequentially heat an impurity condensation zone provided with a pure iron filter material in the crucible, the setting temperature of the second section is 700-plus-1300 ℃, and the setting temperature of the third section is 700-plus-800 ℃. In the method provided by the invention, the heating is carried out in three sections, wherein the first section is mainly used for heating a magnesium raw material to generate magnesium vapor, and the second section and the third section are used for keeping the magnesium vapor state and heating a pure iron filter material, so that the pure iron filter material can ensure the optimal working temperature and is beneficial to removing impurities in the magnesium vapor.
Preferably, in the step (2), the heating is performed in three sections, wherein the first section heats the reaction zone of the crucible provided with the magnesium raw material, and the temperature is 1200-1300 ℃; the second section and the third section sequentially heat an impurity condensation zone provided with a pure iron filter material in the crucible, wherein the temperature of the second section is 1200-1300 ℃, and the temperature of the third section is 586-800 ℃. According to the method adopted by the invention, on one hand, the raw material balls can be used as the magnesium source material, and on the other hand, the metal magnesium with the purity of less than 99.99 percent can be used as the magnesium source material. When the raw material ball is used as the magnesium source material, the magnesium source material needs to be subjected to chemical reaction, so that the temperature for heating the magnesium source material needs to be over 1200 ℃, the vacuum degree is below 20Pa, and the reduced material ball can react at the temperature and the vacuum degree and obtain magnesium vapor.
Preferably, in the step (2), the heating temperature is 700-. Further preferably, the first section heats the reaction area of the crucible provided with the magnesium raw material, and the temperature is 700-; the second section and the third section sequentially heat an impurity condensation zone provided with a pure iron filter material in the crucible, the temperature of the second section is 700-1050 ℃, and the temperature of the third section is 700-800 ℃.
The magnesium source material provided by the invention can be metal magnesium containing impurities besides the reducing material balls, when the metal magnesium is used as the magnesium source material, because the melting point of the magnesium is 649.85 ℃ and the boiling point is 1094.54 ℃, the evaporation is generally carried out by adopting a conventional vacuum distillation method under the vacuum degree of 10Pa and below 750 ℃, and the magnesium source material can be heated to more than 750 ℃ and below 1094.54 ℃, so that the evaporation rate of the magnesium is greatly improved, and the purification efficiency of the gas-phase magnesium is greatly improved.
Preferably, in the step (2), the purity of the pure iron filter material is 99.2% or more. The higher the purity of the filter material is, the more beneficial to magnesium purification is, and the high-purity iron material can not bring new impurities to the system in the magnesium purification process, thereby being beneficial to obtaining high-purity magnesium. The purity of the pure iron filter material provided by the invention is more than 99.2%, wherein the pure iron filter material does not contain substances which react with magnesium and also does not contain substances which are unstable under working conditions.
Preferably, in the step (2), the pure iron filter material is arranged in an impurity condensation zone in the crucible, and the working temperature of the pure iron filter material is 700-.
Due to the high impurity content in the magnesium raw material, Ca, F and Al impurities are distributed over the respective temperatures of the condensation zone and are usually accompanied, and Mn condensate occurs at 765-832 ℃ and lower. At 700 ℃ and 917 ℃, most impurities in magnesium can be effectively removed on the pure iron filter material. The principle of removing pure iron by its specific affinity for certain impurity elements can be illustrated by simplified thermodynamic calculations. By assuming an initial mixed vapor entry parameter: 98.6mol of Mg, 0.1mol of Al, 0.1mol of Mn0.1mol of Ca and 0.1mol of Zn. Sufficient solid pure iron (1mol) is arranged in the system as a filter material, and the equilibrium state composition of the filter material is determined by utilizing the Gibbs free energy minimum principle at the temperature of 1000 ℃, 900 ℃, 800 ℃, 700 ℃ and the like. As shown in FIG. 1, at 1000 deg.C, 900 deg.C, 800 deg.C, iron can form more stable solid solution with Mn, Al, which are impurities contained in magnesium vapor, and the condensed material is calculated as solid solution with BCC-
The invention provides a gas-phase magnesium purification device containing a pure iron filter material, which comprises an electric furnace body, a crucible, a heating mechanism, a thermocouple and a vacuum mechanism, wherein the crucible is arranged in the electric furnace body;
the crucible comprises a reaction zone, an impurity condensation zone and a crystallization zone which are arranged in sequence,
the reaction zone is provided with a hopper,
the impurity condensing zone is provided with a filtering component,
the filter component is provided with a filter material which is made of pure iron,
the crystallization zone is provided with a crystallizer;
the vacuum mechanism is arranged in the electric furnace body, and the crucible is arranged in the vacuum mechanism;
the thermocouple is arranged on the outer wall of the crucible;
the heating mechanism is arranged in the electric furnace body to heat the crucible.
In order to realize the purpose of purifying magnesium by utilizing the method for purifying the gas-phase magnesium of the pure iron filter material, the invention provides a device matched with the method for use, a filtering component is arranged in a crucible impurity condensation zone in the device, the pure iron filter material is arranged in the filtering component, in addition, a heating mechanism for realizing magnesium gas phase, a thermocouple and a vacuum mechanism for keeping the vacuum degree of a system are also arranged, and the device can ensure reasonable temperature and vacuum degree in the magnesium purifying process and can ensure that the filter material can remove gas-phase impurities in the magnesium purifying process.
The device provided by the invention has a simple structure, is suitable for large-scale industrial production, improves the efficiency of purifying magnesium, and has great economic benefit.
The filter assembly in the device provided by the invention can be detached, impurities attached to the filter material can be removed in acid washing and other modes, the purpose of repeatedly using the filter material for multiple times is achieved, and the production cost is reduced.
According to the device for purifying magnesium in gas phase, which comprises the pure iron filter material, the filter material is preferably one of foam metal iron, iron fiber or iron microspheres, and the purity of the filter material is more than 99.2%.
According to the device for purifying gas-phase magnesium containing the pure iron filter material provided by the invention, preferably, when the filter material is foamed metal iron, the aperture of the foamed metal iron is below 30ppi, when the filter material is iron fiber, the aperture of the iron fiber is 100-400 meshes, and when the filter material is iron microsphere, the particle size of the iron microsphere is 45-5000 μm.
The pure iron filter material in the device provided by the invention has special affinity with impurities in magnesium vapor, is used as a nucleation site of the impurities in the magnesium vapor to reduce a nucleation energy barrier and enable the impurities to be deposited in advance, and has a physical interception function of the filter material. No matter the filter material is used as a nucleation site of impurities or physical interception, the iron material can be realized only by needing a larger contact area with magnesium vapor, and the iron material adopts a form of foam metal iron, iron fiber or iron microspheres, so that the contact area of the filter material and the magnesium vapor can be effectively increased, and the filtering efficiency is improved.
The gas-phase magnesium purification device containing the pure iron filter material provided by the invention preferably has the advantage that the crystallization zone is provided with a plurality of crystallizers arranged in a step-by-step manner.
The device provided by the invention is provided with the plurality of crystallizers, the plurality of crystallizers are arranged step by step, most impurities in magnesium are retained in the pure iron filter material in the impurity condensation zone in the magnesium purification process, but zinc cannot be removed through the pure iron filter material, and the zinc can be removed through the multistage crystallizers.
The device for purifying magnesium in gas phase containing the pure iron filter material provided by the invention preferably comprises a heating mechanism, a heating mechanism and a control mechanism, wherein the heating mechanism comprises a first heating component, a second heating component and a third heating component; the first heating assembly heats a reaction zone of the crucible; the second heating assembly and the third heating assembly heat an impurity condensing region of the crucible. The purpose of multistage temperature control is to accurately control the temperature and prolong the length of the proper filter material working temperature. Therefore, the multi-stage temperature control is more accurate in temperature gradient, the physical space for properly removing impurities is longer, and the high-purity magnesium can be obtained more favorably.
The device for purifying the gas-phase magnesium containing the pure iron filter material, provided by the invention, preferably comprises a vacuum cabin, a water-cooling flange, an end cover and a vacuumizing assembly, wherein the vacuum cabin is provided with a vacuum cavity; the vacuum cabin body is arranged inside the electric furnace body; the water-cooling flanges are arranged at two ends of the vacuum cabin body; the end cover is arranged at the end part of the water-cooling flange far away from the vacuum cabin body; the vacuumizing assembly can vacuumize the interior of the vacuum cabin; the crucible is arranged inside the vacuum cabin.
According to the invention, different sections of the crucible are heated through the first heating assembly, the second heating assembly and the third heating assembly, the temperature in the crucible is monitored through the thermocouple arranged on the outer wall of the crucible, and the temperature of the crucible is used as feedback to adjust. The water-cooled flanges at the two ends mainly reduce the temperature of the flange interface, protect the flange rubber ring from being burnt by overheating, and keep vacuum. In addition, the temperature of the crystallizer can also be indirectly adjusted by adjusting the flow rate of the cooling water.
According to the device for purifying the gas-phase magnesium containing the pure iron filter material, provided by the invention, preferably, the crucible is formed by assembling a plurality of sections of high-purity graphite pipe fittings, and the two sections of pipe fittings are connected in an insertion manner. The thermocouples in the invention are arranged on different sections of the high-purity graphite pipe fitting and are used for monitoring the temperature of each section of the crucible.
The high-purity graphite pipe fitting is prepared by taking high-purity graphite as a raw material, wherein the high-purity graphite means that the carbon content of the graphite is higher than 99.99%.
The invention has the beneficial effects that:
1. the gas-phase magnesium purification method based on the pure iron filter material provided by the invention adopts the pure iron filter material to filter magnesium vapor under specific temperature and vacuum degree. The application of the pure iron filter material in the gas-phase magnesium purification process breaks through the technical prejudice that the iron contact is avoided as much as possible in the traditional magnesium purification process. The invention provides a method for purifying magnesium by gas phase by using pure iron as a filter material, wherein the pure iron does not react with magnesium vapor on one hand, does not form a more stable substance with magnesium thermodynamically, and does not bring new impurities to a system; on the other hand, Mn and Al in the magnesium vapor have special affinity with iron, and can form a stable solid solution with the iron at a higher temperature, so that some impurities are removed; meanwhile, pure iron can be used as a nucleation site of impurities in the magnesium vapor, so that the nucleation energy barrier is reduced, and certain impurities are deposited in advance, thereby removing the impurities in the magnesium vapor.
2. The method provided by the invention can be applied to industrial large-scale gas-phase magnesium purification, the evaporation rate is exponentially improved by improving the temperature of the system, so that the production efficiency of magnesium purification can be improved in a magnitude order, and on the premise of industrial large-scale crude production, the method provided by the invention can reduce the content of Mn impurities, Al impurities and Ca impurities in the magnesium raw material to be below 20ppm, 10ppm and 20ppm, simultaneously remove non-metallic impurity elements such as F, Cl and S, improve the product purity, and ensure that the purity of the obtained magnesium is more than 99.99 percent
3. The method provided by the invention simplifies the production process flow, impurities such as Mn, Al, Ca, F, Cl and the like are mainly enriched on the filter material, a multi-stage tower tray is not required to be arranged, the yield of high-purity magnesium is obviously improved, and thus the production cost of the high-purity magnesium is obviously reduced.
4. The device provided by the invention has a simple structure, is suitable for large-scale industrial production, improves the efficiency of purifying magnesium, and has great economic benefit. The filter assembly in the device provided by the invention can be detached, impurities attached to the filter material can be removed in acid washing and other modes, the purpose of repeatedly using the filter material for multiple times is achieved, and the production cost is reduced.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a diagram showing the thermodynamic calculation results of the composition and content of condensed substances at different temperatures;
FIG. 2 is a schematic structural view of the apparatus provided in example 1;
FIG. 3a is a Scanning Electron Microscope (SEM) representation of the iron foam of the filter media (200 μm on scale) prior to the experiment of example 6;
FIG. 3b is a Scanning Electron Microscope (SEM) representation of the iron foam of the filter media (10 μm on scale) prior to the experiment of example 6;
FIG. 4 is a schematic representation of the energy dispersive X-ray spectroscopy (EDS) of metallic iron foam filter media prior to the experiment of example 6;
FIG. 5a is a Scanning Electron Microscope (SEM) representation of the iron foam filter material after the experiment of example 6 (scale 200 μm);
FIG. 5b is a Scanning Electron Microscope (SEM) representation of the iron foam filter material after the experiment of example 6 (10 μm scale);
FIG. 6 is a schematic representation of the energy dispersive X-ray spectroscopy (EDS) of the metallic iron filter foam after the experiment of example 6;
FIG. 7 is a schematic view of a Scanning Electron Microscope (SEM) of the inner wall of graphite tubes Nos. 1 to 4 after the experiment of example 6;
FIG. 8 is a schematic representation of energy dispersive X-ray spectroscopy (EDS) of the inner wall of graphite tubes Nos. 1-4 after the experiment of example 6;
FIG. 9 is a schematic view of a Scanning Electron Microscope (SEM) of the inner wall of graphite tubes No. 6-8 after the experiment of example 6;
FIG. 10 is a schematic representation of energy dispersive X-ray spectroscopy (EDS) of the inner wall of graphite tubing Nos. 6-8 after the experiment of example 6;
FIG. 11 is a topographical map of the high purity magnesium obtained in example 6.
In the figure 1, an electric furnace body; 2. a crucible; 3. a heating mechanism; 4. a thermocouple; 5. a vacuum mechanism; 21. a reaction zone; 22. an impurity condensation zone; 23. a crystallization zone; 211. a hopper; 221. a filter assembly; 231. a crystallizer; 31. a first heating assembly; 32. a second heating assembly; 33. a third heating assembly; 51. a vacuum chamber; 52. water-cooling the flange; 53. an end cap; 54. and a vacuum pumping assembly.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the examples given herein without any inventive step, are within the scope of the present invention.
- 上一篇：一种医用注射器针头装配设备
- 下一篇：一种镍基高温合金的电渣重熔工艺