Microwave heating carbon thermal method magnesium metal vacuum reduction furnace

Abstract

The utility model provides a microwave heating carbon thermal method magnesium metal vacuum reduction furnace. The microwave heating carbon thermal method magnesium metal vacuum reduction furnace comprises a furnace shell, a silicon nitride furnace tube is fixedly installed on the furnace shell, a crystallizer barrel is fixedly installed on one side of the furnace shell, and a crystallizer baffle located in the crystallizer barrel is fixedly installed at the end, away from the furnace shell, of the crystallizer barrel. A cooling water jacket fixedly connected with the furnace shell is arranged on the outer side of the crystallizer barrel in a sleeving manner, a reduction tank cover is fixedly mounted at one end, far away from the furnace shell, of the cooling water jacket, a thermocouple is arranged at one end, far away from the crystallizer barrel, of the furnace shell, and one end of the thermocouple extends into the silicon nitride furnace tube. The microwave heating carbon thermal method magnesium metal vacuum reduction furnace provided by the utility model has the advantages that the high temperature resistance is good, and the problem that crystals are difficult to form due to excessive powder generated after magnesium steam is condensed in carbon thermal method reduction can be solved.

Description

Technical Field

[0001] The utility model relates to the technical field of metal smelting, in particular to a microwave heating carbothermal method magnesium metal vacuum reduction furnace. Background Art

[0002] The existing microwave vacuum reduction technology for magnesium metal basically remains at the stage of laboratory miniaturization experiments. The experimental device generally places the raw materials required for reduction in a microwave resonant cavity made of stainless steel that can be evacuated for heating and reduction. A water-cooled crystallization device is connected outside the resonant cavity to condense magnesium vapor, and the magnesium vapor is directly condensed on the inner wall of the water-cooled jacket.

[0003] Since the existing microwave vacuum reduction technology of magnesium metal adopts the method of vacuuming the resonant cavity and connecting an external water-cooling crystallization device, this technology has the following characteristics:

[0004] 1. The resonant cavity of metal materials is very likely to produce plasma under high vacuum conditions, causing the "sparking" phenomenon, which leads to microwave power dissipation, thereby reducing heating efficiency. In addition, the local high temperature caused by the "sparking" phenomenon is very likely to cause equipment burns;

[0005] 2. The reduction system and the condensation system are indirectly connected, and the magnesium vapor condenses directly on the inner wall of the water-cooling jacket. Such equipment connection and condensation methods result in the magnesium vapor having a large temperature gradient during the condensation process, and the liquid phase exists for too short a time, which is not conducive to the formation of crystals and is more likely to form powdered magnesium powder.

[0006] Therefore, it is necessary to provide a new microwave-heated carbothermal magnesium vacuum reduction furnace to solve the above technical problems. Utility Model Content

[0007] The technical problem solved by the utility model is to provide a microwave heating carbothermal magnesium vacuum reduction furnace which has good high temperature resistance and can solve the problem that too much powder is generated after condensation of magnesium vapor in carbothermal reduction and is difficult to form crystals.

[0008] In order to solve the above technical problems, the utility model provides a microwave heated carbon thermal method magnesium vacuum reduction furnace comprising: a furnace shell, on which a silicon nitride furnace tube is fixedly installed, a crystallizer tube is fixedly installed on one side of the furnace shell, a crystallizer baffle located in the crystallizer tube is fixedly installed at one end of the crystallizer tube away from the furnace shell, a cooling water jacket fixedly connected to the furnace shell is sleeved on the outer side of the crystallizer tube, a reduction tank cover is fixedly installed at one end of the cooling water jacket away from the furnace shell, a thermocouple is provided at one end of the furnace shell away from the crystallizer tube, one end of the thermocouple extends into the silicon nitride furnace tube, a heat shield is fixedly installed at one end of the silicon nitride furnace tube close to the reduction tank cover, and high-purity alumina fiber is filled between the silicon nitride furnace tube and the furnace shell.

[0009] Preferably, a first vacuum flange is fixedly mounted on one end of the cooling water jacket away from the furnace shell, the reduction tank cover is connected to the cooling water jacket via the first vacuum flange, and a rubber sealing ring is provided between the cooling water jacket and the first vacuum flange.

[0010] Preferably, a second vacuum flange is fixedly mounted on the cooling water jacket, and the second vacuum flange is connected to the interior of the cooling water jacket through a pipeline.

[0011] Preferably, a first water-cooled casting flange is fixedly mounted on one end of the cooling water jacket close to the furnace shell, the first water-cooled casting flange is fixedly connected to the furnace shell, and a carbon packing ring is provided between the water-cooled casting flange and the silicon nitride furnace tube.

[0012] Preferably, the outer fixed sleeve of the silicon nitride furnace tube is provided with a second water-cooled casting flange, and the second water-cooled casting flange is fixedly connected to the first water-cooled casting flange.

[0013] Preferably, a thermocouple flange is fixedly mounted on a side of the furnace shell away from the crystallizer tube, the thermocouple is mounted in the thermocouple flange, and the thermocouple penetrates the high-purity alumina fiber and extends into the silicon nitride furnace tube.

[0014] Preferably, a fluororubber sealing ring is provided between the thermocouple flange and the furnace shell.

[0015] Preferably, a plurality of microwave magnetrons are fixedly mounted on the outer side of the furnace shell.

[0016] Compared with the related art, the microwave heating carbothermal magnesium vacuum reduction furnace provided by the utility model has the following beneficial effects:

[0017] 1. The reaction chamber is made of silicon nitride ceramics, and the diameter of the single component can reach 500mm, which can be industrialized. The excellent high temperature resistance, wave transmission performance, thermal shock resistance and other characteristics of silicon nitride ceramics can ensure a longer service life of the furnace tube;

[0018] 2. A reaction cavity made of silicon nitride ceramic tube, in which the silicon nitride furnace tube is placed in a microwave resonant cavity. During microwave heating, only the interior of the silicon nitride furnace tube is in a high vacuum state. This method limits the generation of plasma to the interior of the silicon nitride furnace tube, thus avoiding damage to metal parts such as the resonant cavity and magnetron;

[0019] 3. The crystallization surface of the water-cooled crystallizer adopted in the utility model is indirectly water-cooled and seamlessly connected with the silicon nitride furnace tube. The indirect slow cooling method allows the magnesium vapor to stay in the liquid phase longer during the condensation process, making it easier to form crystals. This successfully solves the problem of excessive powder generated after the condensation of magnesium vapor in carbothermal reduction, which is difficult to form crystals. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic structural diagram of a preferred embodiment of a microwave-heated carbothermal magnesium vacuum reduction furnace provided by the utility model;

[0021] Figure 2 for Figure 1 The side cross-sectional structural schematic diagram shown;

[0022] Figure 3 for Figure 1 An enlarged schematic diagram of part A is shown.

[0023] Numbers in the figure: 1. reduction tank cover, 2. rubber sealing ring, 3. first vacuum flange, 4. second vacuum flange, 5. cooling water jacket, 6. crystallizer baffle, 7. crystallizer cylinder, 8. first water-cooled casting flange, 9. carbon packing ring, 10. second water-cooled casting flange ring, 11. heat shield, 12. silicon nitride furnace tube, 13. high-purity alumina fiber, 14. furnace shell, 15. thermocouple flange, 16. thermocouple, 17. microwave magnetron, 18. fluororubber sealing ring. DETAILED DESCRIPTION

[0024] The utility model is further described below in conjunction with the accompanying drawings and implementation modes.

[0025] Please refer to Figure 1 , Figure 2 and Figure 3 ,in, Figure 1 A schematic structural diagram of a preferred embodiment of a microwave-heated carbothermal magnesium vacuum reduction furnace provided by the utility model;

[0026] Figure 2 for Figure 1 The side cross-sectional structural schematic diagram shown; Figure 3 for Figure 1The enlarged schematic diagram of part A is shown. The microwave-heated carbon thermal magnesium vacuum reduction furnace comprises: a furnace shell 14, on which a silicon nitride furnace tube 12 is fixedly installed, a crystallizer tube 7 is fixedly installed on one side of the furnace shell 14, and a crystallizer baffle 6 located in the crystallizer tube 7 is fixedly installed at one end of the crystallizer tube 7 away from the furnace shell 14, and a cooling water jacket 5 fixedly connected to the furnace shell 14 is sleeved on the outer side of the crystallizer tube 7, and a reduction tank cover 1 is fixedly installed at one end of the cooling water jacket 5 away from the furnace shell 14, and a thermocouple 16 is provided at one end of the furnace shell 14 away from the crystallizer tube 7, and one end of the thermocouple 16 extends into the silicon nitride furnace tube 12, and a heat shield 11 is fixedly installed at one end of the silicon nitride furnace tube 12 close to the reduction tank cover 1, and high-purity alumina fiber 13 is filled between the silicon nitride furnace tube 12 and the furnace shell 14.

[0027] A first vacuum flange 3 is fixedly mounted on one end of the cooling water jacket 5 away from the furnace shell 14 , and the reduction tank cover 1 is connected to the cooling water jacket 5 via the first vacuum flange 3 . A rubber sealing ring 2 is provided between the cooling water jacket 5 and the first vacuum flange 3 .

[0028] A second vacuum flange 4 is fixedly mounted on the cooling water jacket 5 , and the second vacuum flange 4 is connected to the interior of the cooling water jacket 5 through a pipeline.

[0029] A first water-cooled casting flange 8 is fixedly mounted on one end of the cooling water jacket 5 close to the furnace shell 14 . The first water-cooled casting flange 8 is fixedly connected to the furnace shell 14 . A carbon packing ring 9 is provided between the water-cooled casting flange and the silicon nitride furnace tube 12 .

[0030] The outer fixed sleeve of the silicon nitride furnace tube 12 is provided with a second water-cooled casting flange 10 , and the second water-cooled casting flange 10 is fixedly connected to the first water-cooled casting flange 8 .

[0031] A thermocouple flange 15 is fixedly mounted on one side of the furnace shell 14 away from the crystallizer tube 7 . The thermocouple 16 is mounted in the thermocouple flange 15 . The thermocouple 16 penetrates the high-purity alumina fiber 13 and extends into the silicon nitride furnace tube 12 .

[0032] A fluororubber sealing ring 18 is provided between the thermocouple flange 15 and the furnace shell 14 .

[0033] A plurality of microwave magnetrons 17 are fixedly mounted on the outer side of the furnace shell 12 .

[0034] The microwave heating carbon thermal method magnesium metal vacuum reduction furnace provided by the utility model adopts a cylindrical furnace shell 14 made of stainless steel plate as a microwave resonant cavity, a silicon nitride furnace tube 12 as a reduction tank is horizontally arranged in the center of the resonant cavity, and is also equipped with a heat shield 11, a crystallizer baffle 6, a crystallizer tube 7 and a cooling water jacket 5 and other components. The silicon nitride furnace tube 12 is connected with the cooling water jacket 5 and the rear reduction tank cover 1 by a casting water-cooling flange, and the sealing adopts a high-temperature resistant carbon packing ring 9. The entire high-temperature area adopts high-purity alumina fiber 13 as a heat-insulating material. A cooling water jacket 5 is arranged on the periphery of the crystallizer tube 7 to facilitate cooling the crystallizer tube 7 and the rubber sealing ring 2. At the same time, the circulating water cooling jacket 5 and the outer wall of the crystallizer tube 7 maintain a certain distance to reduce the temperature gradient. A second vacuum flange is arranged above the water cooling jacket 5, and an external vacuum pump controls the vacuum state inside the silicon nitride furnace tube 12. When the furnace is working, the mixed pellets pressed with forging white, coke powder and fluorite as raw materials are loaded into the silicon nitride furnace tube 12 with a filling rate of 75%. The inside of the silicon nitride furnace tube 12 is in a vacuum state of 10-20pa. The pellets absorb electromagnetic waves to reach a high temperature of 1300-1350°C to reduce the metal magnesium. The CO gas and magnesium vapor generated by the reaction are extracted from the reaction zone through the vacuum system. The magnesium vapor condenses and crystallizes on the crystallizer, and the CO gas is collected and stored through the pipeline. A heat shield 11 is set at the end of the reduction zone and at the connection with the crystallization zone to prevent heat from radiating from the high temperature zone to the low temperature zone. The crystallization zone is partially indirectly water-cooled to ensure the temperature gradient requirements for the condensation of magnesium vapor into a crystalline state and the condensation of impurities. After the reaction is completed, the crystallized magnesium is collected at the crystallization plate, and the reaction residue is discharged from the reduction tank cover 1.

[0035] Compared with the related art, the microwave heating carbothermal magnesium vacuum reduction furnace provided by the utility model has the following beneficial effects:

[0036] 1. The reaction chamber is made of silicon nitride ceramics, and the diameter of the single component can reach 500mm, which can be industrialized. The excellent high temperature resistance, wave transmission performance, thermal shock resistance and other characteristics of silicon nitride ceramics can ensure a longer service life of the furnace tube;

[0037] 2. A reaction cavity made of silicon nitride ceramic tube, in which the silicon nitride furnace tube is placed in a microwave resonant cavity. During microwave heating, only the interior of the silicon nitride furnace tube is in a high vacuum state. This method limits the generation of plasma to the interior of the silicon nitride furnace tube, thus avoiding damage to metal parts such as the resonant cavity and magnetron;

[0038] 3. The crystallization surface of the water-cooled crystallizer adopted in the utility model is indirectly water-cooled and seamlessly connected with the silicon nitride furnace tube. The indirect slow cooling method allows the magnesium vapor to stay in the liquid phase longer during the condensation process, making it easier to form crystals. This successfully solves the problem of excessive powder generated after the condensation of magnesium vapor in carbothermal reduction, which is difficult to form crystals.

[0039] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A microwave heated carbothermal magnesium vacuum reduction furnace, characterized in that: include: A furnace shell, wherein a silicon nitride furnace tube is fixedly mounted on the furnace shell, a crystallizer tube is fixedly mounted on one side of the furnace shell, a crystallizer baffle located in the crystallizer tube is fixedly mounted on one end of the crystallizer tube away from the furnace shell, a cooling water jacket fixedly connected to the furnace shell is sleeved on the outer side of the crystallizer tube, a reduction tank cover is fixedly mounted on the end of the cooling water jacket away from the furnace shell, a thermocouple is provided on the end of the furnace shell away from the crystallizer tube, one end of the thermocouple extends into the silicon nitride furnace tube, a heat shield is fixedly mounted on one end of the silicon nitride furnace tube close to the reduction tank cover, and high-purity alumina fiber is filled between the silicon nitride furnace tube and the furnace shell.

2. The microwave-heated carbothermal magnesium vacuum reduction furnace according to claim 1, characterized in that: A first vacuum flange is fixedly mounted on one end of the cooling water jacket away from the furnace shell, the reduction tank cover is connected to the cooling water jacket via the first vacuum flange, and a rubber sealing ring is provided between the cooling water jacket and the first vacuum flange.

3. The microwave-heated carbothermal magnesium vacuum reduction furnace according to claim 1, characterized in that: A second vacuum flange is fixedly mounted on the cooling water jacket, and the second vacuum flange is connected to the interior of the cooling water jacket through a pipeline.

4. The microwave-heated carbothermal magnesium vacuum reduction furnace according to claim 1, characterized in that: A first water-cooled casting flange is fixedly mounted on one end of the cooling water jacket close to the furnace shell. The first water-cooled casting flange is fixedly connected to the furnace shell. A carbon packing ring is provided between the water-cooled casting flange and the silicon nitride furnace tube.

5. The microwave-heated carbothermal magnesium vacuum reduction furnace according to claim 4, characterized in that: The outer fixed sleeve of the silicon nitride furnace tube is provided with a second water-cooled casting flange, and the second water-cooled casting flange is fixedly connected to the first water-cooled casting flange.

6. The microwave-heated carbothermal magnesium vacuum reduction furnace according to claim 1, characterized in that: A thermocouple flange is fixedly mounted on one side of the furnace shell away from the crystallizer tube. The thermocouple is mounted in the thermocouple flange, and the thermocouple penetrates the high-purity alumina fiber and extends into the silicon nitride furnace tube.

7. The microwave-heated carbothermal magnesium vacuum reduction furnace according to claim 6, characterized in that: A fluororubber sealing ring is provided between the thermocouple flange and the furnace shell.

8. The microwave-heated carbothermal magnesium vacuum reduction furnace according to claim 1, characterized in that: A plurality of microwave magnetrons are fixedly mounted on the outer side of the furnace shell.

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