CN1302133C - High-vacuum in-situ refining apparatus for extracting high-purity material - Google Patents

Abstract

The invention discloses a high-vacuum in-situ refining device for refining high-purity and ultra-high-purity materials. The high-vacuum refining device consists of a refining chamber, a vacuum system, a diffusion furnace, a crucible, a feeding and retrieving system, and a protective gas The device and the industrial intelligent temperature controller connect various parts through vacuum pipe fittings, gas circuits and wires to form the whole refining device. The device has the outstanding advantages of effectively removing impurities with high saturated vapor pressure and impurities with low saturated vapor pressure in stages. At the same time, the refining process always maintains a high vacuum state, and the entire production process is isolated from the atmosphere, which greatly reduces the pollution of the atmosphere to raw materials. The device has high product quality, large production capacity, stable and reliable performance, and is suitable for the production of high-purity and ultra-high-purity materials, especially the preparation of high-activity high-purity materials.

Description

A high vacuum in-situ refining device for refining high-purity materials

technical field

The invention relates to a high-vacuum in-situ refining device for producing high-purity and ultra-high-purity materials, which belongs to the field of high-purity and ultra-high-purity material smelting in metallurgy and chemical industry.

Background technique

High-purity materials such as high-purity metals, high-purity non-metals, and high-purity inorganic compound materials are widely used in the preparation of compound semiconductor materials and devices, as well as in aviation, aerospace and other fields, such as zinc used in II-VI and III-V compound semiconductors. , magnesium, calcium, aluminum, arsenic, phosphorus and other metal and non-metallic materials, the purity of which should be above 99.999% (5N), otherwise too many impurities will seriously affect the crystallinity and photoelectric properties of semiconductor materials, thereby greatly reducing the performance of the device . At present, the production of high-purity metals mostly adopts vacuum distillation method or regional smelting method, etc., such as Chinese patents 98113973.6, 200320115091.0, 200320115092.5 and foreign patents KR2004022842-A, RU2236476-C1, JP10121163-A and other reported refining equipment and methods. At high temperature, the vacuum degree is generally between 10 Pa and 0.01 Pa, and there is still a lot of residual gas in the vacuum chamber, which is quite harmful to the extraction of active metals; in addition, in the process of refining high-purity metals, the The separation and removal effects are very different, and there is a lack of methods to efficiently remove impurities with high saturated vapor pressure and low saturated vapor pressure at the same time, thus affecting the overall purification effect. At present, the production of high-purity metals generally adopts wet production process, which is harmful to the environment and the product quality is unstable. In addition, some inorganic compound materials are mostly prepared by reaction methods, and there is still a lack of efficient purification methods.

Contents of the invention

The purpose of the present invention is to provide a brand-new high-vacuum in-situ refining device for refining high-purity materials in view of the deficiencies of the prior art, which can greatly improve the purification effect, not only stable and reliable in quality, but also environmentally friendly for the extraction of high-purity materials The technology and equipment have important industrial application value.

In order to achieve the above object, a high vacuum in-situ refining device for refining high-purity materials of the present invention includes: a vacuum system, a refining chamber, a diffusion furnace, a crucible, a feeding and retrieving system, a protective gas device and an industrial intelligent temperature control (referred to as temperature controller); the feeding and reclaiming system is connected to the refining chamber, the diffusion furnace is installed at the bottom of the refining chamber, the crucible is set in the diffusion furnace, the temperature controller is connected to the diffusion furnace through thermocouple compensation lines and wires, and the vacuum The system is respectively connected with the refining chamber and the protective gas device. There are two independent heating wires in the diffusion furnace, that is, the upper heating wire and the lower heating wire, which can heat the upper and lower parts of the crucible respectively to form an upper high and lower lower or upper Low and high temperature distribution; a crucible cover is also installed on the mouth of the crucible, and small holes are evenly distributed on the crucible cover; a condensation baffle for collecting high saturated vapor pressure impurities is also installed on the upper part of the refining chamber.

Further, the vacuum system includes a backing pump, a molecular pump, an ion pump and a vacuum degree measuring instrument, the molecular pump is connected to the backing pump, and the backing pump includes vacuum pumps such as mechanical pumps or dry pumps, and the backing pump Install resistance gauge and ion gauge or composite gauge between the molecular pump.

Further, the refining chamber is divided into upper and lower parts, connected by a gate valve, the upper part of the refining chamber is connected with the molecular pump through another gate valve, the lower part of the refining chamber is connected with the ion pump, and the upper part of the refining chamber is also Install ion gauge or compound gauge.

Further, the feeding and retrieving system is composed of a shift fork installed on the upper part of the refining chamber, a magnetic hand, a fast feeding valve, an observation window, a hook on the inner wall of the chamber, and a transparent sealed box, and the transparent sealed box is connected to the upper part of the refining chamber .

Further, the protective gas device includes a high-pressure gas cylinder, a pressure reducing valve, a gas circuit and a leakage valve, and the protective gas device is respectively connected to the air inlet of the molecular pump and the air inlet of the transparent sealed box.

Furthermore, the upper part of the crucible is equipped with a handle, which can cooperate with the shift fork to take out the crucible from the diffusion furnace, move it to the upper part of the refining chamber, and then take it out through the feeding valve.

In the present invention, the temperature of the upper part and the lower part of the crucible is independently controlled by a double heating wire diffusion furnace, and the temperature distribution of the upper part and the lower part and the upper part and the lower part are formed at different stages. Saturated vapor pressure impurities, the first step: the crucible is heated up in sections according to the temperature distribution of the upper part and the lower part to remove the high saturated vapor pressure impurities. The second step: the crucible forms a temperature distribution of the upper part and the lower part, and the temperature of the lower part is raised to the highest point Keep it for a certain period of time, let the raw material in the lower part evaporate, and crystallize or condense at a place with a lower temperature near the mouth of the crucible, and separate the purified material from impurities with low saturated vapor pressure, thereby obtaining a high-purity material. In addition, the present invention also has the following advantages:

1. The high-vacuum in-situ refining device of the present invention is completely isolated from the atmosphere through the tight connection between the sealed box and the refining chamber, and the entire production process is carried out under the protective gas. At the same time, according to the characteristics of the material, the protective gas can be flexibly selected, thereby greatly reducing Pollution of high-purity materials by various components in the air;

2. When refining materials, the entire refining chamber maintains a high vacuum state, and the low pressure is below 1×10 ^-4 Pa; when feeding materials, the upper part of the refining chamber is filled with protective gas, but the lower part of the refining chamber is separated from the upper part by a gate valve , and use the ion pump to pump air, and still maintain a high vacuum state, thereby effectively reducing the reaction and recombination of high-purity materials at high temperatures during refining and residual gases, greatly reducing the impact of gases on materials, especially suitable for active materials. Purify;

3. During production, the workers are completely isolated from the refining materials, and the working conditions are good; the toxic steam generated during refining can be discharged through the vacuum system or collected in the condensation baffle, with little pollution;

4. The device of the present invention has simple structure, firmness and durability, simple and convenient operation, and stable product quality;

5. The present invention is very suitable for combining multiple sets of transparent sealed boxes in series to form an assembly line, with high production efficiency and large output.

Description of drawings

Fig. 1 is a block diagram of a high vacuum in-situ refining device for refining high-purity materials according to the present invention.

1. Refining chamber, 2. Vacuum system, 3. Diffusion furnace, 4. Crucible, 5. Feeding and reclaiming system, 6. Protective gas device, 7. Temperature controller.

Fig. 2 is a schematic diagram of the main structure of the high vacuum in-situ refining device of the present invention.

8 Upper part of refining chamber, 9 Lower part of refining chamber, 10, 41 Gate valve, 11 Transparent sealed chamber, 3 Diffusion furnace, 4 Crucible, 7 Temperature controller, 12 Molecular pump, 13 Backing pump, 14 Ion pump, 15 Ion Gauge or composite gauge, 16 resistance gauges, 17 protective gas cylinders, 18 condensation baffles.

Figure 3 is a schematic structural diagram of the feeding and reclaiming system.

11 Transparent sealed box, 19 Quick feed valve, 20 Shift fork, 21 Magnetic hand, 22 Observation window, 23 Cavity inner wall hook, 4 Crucible, 24 Glove port.

Fig. 4 is a schematic structural diagram of a special diffusion furnace used for refining high-purity materials in the present invention.

25 furnace shell, 26 radiation-proof metal cylinder, 27PBN insulating bracket, 28 upper heating wire, 29 lower heating wire, 30 upper thermocouple, 31 lower thermocouple, 32 multi-layer radiation-proof metal sheet, 33 vacuum flange, 34 Thermocouple connector, 35 power connector.

Fig. 5 is a schematic structural diagram of a crucible for refining high-purity materials in the present invention.

36 crucible main bodies, 37 crucible lids, 38 crucible hooks.

Fig. 6 is a physical photo before and after applying the device of the present invention to extract high-purity magnesium.

39 Magnesium particles with a purity of 99.95% before refining, and 40 recrystallized magnesium particle clusters obtained after refining.

Detailed ways

The present invention will be described in detail below in conjunction with the embodiments and drawings, but it should not be construed as limiting the protection scope of the present invention.

The block diagram of the high vacuum in-situ refining device of the present invention as shown in Fig. 1, this device comprises: refining chamber 1, vacuum system 2, diffusion furnace 3, crucible 4, feeding and reclaiming system 5, protective gas device 6 and industrial Intelligent temperature controller (thermostat for short) 7. The vacuum system 2 is connected to the refining chamber 1 along the horizontal direction, and the protective gas device 6 is connected to the vacuum system 2 through a valve; while the diffusion furnace 3 and the feeding and retrieving system 5 are respectively connected to the lower and upper parts of the refining chamber 1 along the longitudinal direction. The controller 7 is connected to the diffusion furnace 3 through thermocouple compensation wires and power wires.

The schematic diagram of the main structure of the high vacuum in-situ refining device of the present invention as shown in Figure 2, wherein the refining chamber 1 is composed of the upper part 8 of the refining chamber and the lower part 9 of the refining chamber, which are connected by a gate valve 10; the upper part of the refining chamber 8 and the diffusion furnace 3 Connection, the lower part of the refining chamber 9 is connected to the transparent sealed box 11, and the diffusion furnace 3 is connected to the temperature controller 7 through a thermocouple compensation line and a power lead. The vacuum system 2 is composed of a molecular pump 12 , a backing pump 13 , an ion pump 14 , an ion gauge 15 and a resistance gauge 16 . The molecular pump 12 is connected to the upper part 8 of the refining chamber through a gate valve 41 , and the molecular pump 12 is connected to the protective gas cylinder 17 through a leakage valve and a pressure regulating valve. The ion pump 14 is connected with the lower part 9 of the refining chamber through a gate valve 10 . A condensing baffle 18 is also installed on the top of the gate valve 10 for condensing various steams diffused from the mouth of the crucible, which is replaceable and practical and convenient.

The structure diagram of the feeding and retrieving system shown in Figure 3 is composed of a transparent sealed box 11, a fast feeding valve 19, a shift fork 20, a magnetic hand 21, an observation window 22, a hook 23 on the inner wall of the cavity, and a crucible 4. When feeding, first put an appropriate amount of raw materials into the crucible in a transparent sealed box, then hang the crucible 4 on the hook 23 on the inner wall of the cavity, and cover the feed valve 19 tightly. High vacuum is drawn, and then the gate valve 10 of the refining chamber 1 is opened, and the crucible 4 is put into the diffusion furnace 3 by using the shift fork 20 . And when taking material, utilize shift fork 20 to take out crucible from diffusion furnace 3, and hang on the hook 23; , take out the crucible 4 and put it into the transparent sealed box 11; then take out the material from the crucible 4, select the recrystallized part in the middle for sampling and testing, and package the qualified products. There are glove openings 24 on both sides of the transparent airtight box 11, and related operations are carried out through gloves 24. During the entire production process, high-purity materials are separated from the atmosphere to ensure stable and reliable product quality; at the same time, workers are completely isolated from refined materials, and the production conditions are good. .

As shown in Figure 4, it is a schematic diagram of the diffusion furnace for refining high-purity materials, which is characterized in that an upper and a lower layer of independent heating wires are wound on the PBN insulating support 27, that is, an upper heating wire 28 and a lower heating wire 29, which can realize The independent control of the temperature of the upper and lower parts of the crucible 4 forms temperature distributions with high top and low bottom and high low bottom and high temperature distribution at different stages. The material is refined in two steps under high vacuum conditions, so as to remove impurities with high saturated vapor pressure and low saturated vapor pressure respectively. The first step: the crucible 4 is heated up in stages according to the temperature distribution of the upper part and the lower part to remove the impurities with high saturated vapor pressure; Impurities with high saturated vapor pressure are evaporated from the raw material and then discharged from the small holes of the crucible cover, condensed on the condensation baffle or sucked away by the vacuum system; the purpose of the high temperature in the upper part of the crucible 4 is to prevent the impurity vapor from condensing on the upper part. Step 2: The crucible 4 forms a temperature distribution with the upper part lower than the lower part, raise the temperature of the lower part to the highest point and keep it for a certain period of time, let the raw materials in the lower part evaporate, and recrystallize at a place with a lower temperature near the mouth of the crucible 4, and purify Materials are separated from impurities with low saturated vapor pressure to achieve the purpose of refining high-purity materials. As shown in Figure 4, the other parts of the furnace are the furnace shell 25, the multi-layer radiation-proof metal cylinder 26, the upper thermocouple 30, the lower thermocouple 31, the multi-layer radiation-proof metal sheet 32, the vacuum flange 33, the thermocouple Connector 34, power connector 35; Among them, the furnace shell 25, the radiation-proof metal cylinder 26, and the heating wire are all high-purity refractory materials such as high-purity tantalum, niobium, molybdenum, etc., which are not less than 99.99%, to ensure that the refined raw materials are in the No pollution at high temperature.

As shown in Figure 5, it is a schematic structural diagram of the crucible, which is characterized in that there is a crucible cover 37 on the mouth of the crucible main body 36, which can be closely connected with the crucible, and there are evenly distributed small holes with a diameter of about 1mm on the crucible cover for Discharge high saturated vapor pressure impurities. Fill the crucible with an appropriate amount of raw material so that the whole raw material is located in the area controlled by the heating wire in the lower part of the furnace during refining, that is, the upper surface of the raw material is not higher than the upper end of the lower heating wire. After loading the material, cover the crucible cover 37; the upper part of the crucible main body has a hook 38, which can cooperate with the shift fork to move the crucible, and carry out the operation of feeding and taking materials. The main body of the crucible is made of high-purity PBN, high-purity quartz or high-purity ceramics, and the crucible cover and hook are made of high-purity refractory materials such as high-purity tantalum, niobium, molybdenum, PBN, quartz, high-purity corundum ceramics, etc. In order to ensure that the refined raw materials are pollution-free at high temperatures.

As shown in Fig. 6, it is the physical photo before and after applying the device of the present invention to extract high-purity magnesium. The magnesium particles 38 before extraction are commercially available 99.95% metallic magnesium, and after refining with the device of the present invention, recrystallized magnesium particle clusters 40 are obtained near the mouth of the crucible. We used an inductively coupled plasma optical emission spectrometer to test the purity of magnesium metal before refining, primary refining and secondary refining, and the main impurities contained in it, such as high saturated vapor pressure impurity zinc, low saturated vapor pressure impurity silicon and iron, The results are shown in Table 1; the results show that the purity of magnesium metal after primary refining by the high vacuum in-situ refining device of the present invention reaches more than 99.995%, and the purity after secondary refining reaches more than 99.9992%, which fully meets the requirements of semiconductor materials and devices, aviation And aerospace and other cutting-edge industries, with great economic and social benefits.

Table 1 The purity of the high-purity magnesium obtained from primary refining and secondary refining of the present invention and the analysis comparison of contained main impurities and refining before Refining times Content of main impurities in magnesium metal (ppm) Magnesium purity (%) Zinc (Zn) Silicon (Si) Iron (Fe) Magnesium (Mg) Unrefined Primary Refined Secondary Refined 530.90.2 478.21.9 351.40.2 99.95%≥99.995%≥99.9992%

Claims (6)

1. A high-vacuum in-situ refining device for refining high-purity materials, characterized in that the device includes: a vacuum system, a refining chamber, a diffusion furnace, a crucible, a feeding and retrieving system, a protective gas device and an industrial intelligence Temperature controller; the feeding and reclaiming system is connected to the refining chamber, the diffusion furnace is installed at the bottom of the refining chamber, the crucible is set in the diffusion furnace, the temperature controller is connected to the diffusion furnace through thermocouple compensation lines and wires, and the vacuum system is connected to the refining chamber respectively. The chamber is connected with the protective gas device, and there are two independent heating wires in the diffusion furnace, that is, the upper heating wire and the lower heating wire, which can heat the upper and lower parts of the crucible respectively, so as to form a temperature of upper high and lower lower or upper lower and lower high. distribution; a crucible cover is also installed on the mouth of the crucible, and small holes are evenly distributed on the crucible cover; a condensation baffle for collecting high saturated vapor pressure impurities is also installed on the upper part of the refining chamber. 2. A high-vacuum in-situ refining device for refining high-purity materials according to claim 1, wherein the vacuum system includes a backing pump, a molecular pump, an ion pump and a vacuum degree measuring instrument, and the molecular The pump is connected to the backing pump, and the backing pump includes a mechanical pump or a dry pump, and a resistance gauge, an ion gauge or a composite gauge is installed between the backing pump and the molecular pump. 3. A high-vacuum in-situ refining device for refining high-purity materials according to claim 2, characterized in that the refining chamber is composed of upper and lower parts, connected by a gate valve, and the upper part of the refining chamber is connected to the upper part of the refining chamber. The molecular pump is connected through another gate valve, the lower part of the refining chamber is connected with the ion pump, and the upper part of the refining chamber is also equipped with an ion gauge or a composite gauge. 4. A high-vacuum in-situ refining device for refining high-purity materials according to claim 3, characterized in that the feeding and retrieving system consists of a shift fork installed on the upper part of the refining chamber, a magnetic hand, a fast It is composed of a feed valve, an observation window, a hook on the inner wall of the cavity and a transparent sealing box, and the transparent sealing box is connected with the upper part of the refining cavity. 5. A high-vacuum in-situ refining device for refining high-purity materials according to claim 4, characterized in that the protective gas device includes a high-pressure gas cylinder, a pressure reducing valve, a gas circuit and a leak valve, and the protection gas The gas device is respectively connected to the air inlet of the molecular pump and the air inlet of the transparent sealed box. 6. A high-vacuum in-situ refining device for refining high-purity materials according to claim 5, characterized in that the upper part of the crucible is equipped with a handle, which can cooperate with the shift fork to lift the crucible Take it out from the diffusion furnace, move it to the upper part of the refining chamber, and take it out through the feed valve.

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