Sub-vacuum fused magnesium oxide smelting and carbon dioxide capture and recovery system and process

Abstract

The present invention relates to a sub-vacuum fused magnesium oxide smelting and carbon dioxide capture and recovery system, including a smelting mobile trolley, a furnace body, a smelting furnace barrel, a charging device, an electrode lifting mechanism, a bag dust collector, a transformer and an automatic control system, characterized in that it also includes a carbon dioxide recovery system connected to the bag dust collector, the furnace body is a sub-vacuum furnace body, and the carbon dioxide recovery system includes a flue gas recovery pipe, a vacuum pump, an exhaust gas exhaust pipe and a carbon dioxide recovery pipe. The carbon dioxide capture and recovery method is that the magnesite concentrate powder is smelted under sub-vacuum conditions, and the carbon dioxide gas in the magnesium oxide liquid in the furnace will be forced to be sucked out, and no splashing will occur during smelting, so that production safety is guaranteed, and the cost is effectively reduced. 90% of the carbon dioxide gas is recovered. This smelting process has played a positive role in promoting carbon recovery, carbon neutralization and clean production.

Description

Technical Field

[0001] The invention belongs to the technical field of non-metallic electric melting smelting, and in particular relates to a sub-vacuum electric melting magnesium oxide smelting and carbon dioxide capture and recovery system and process. Background Art

[0002] In recent years, with the rapid development of international and domestic steel smelting industries, the demand for high-quality refractory materials has also increased, especially the use of fused-grade magnesium oxide, but the high-quality raw material magnesite resources in nature are constantly decreasing.

[0003] With the reduction of high-quality magnesite resources, a new magnesite beneficiation process has been developed in the industry. The raw material used for beneficiation is low-grade magnesite that was previously unavailable. High-quality magnesite concentrate is obtained through flotation process, in which the magnesium oxide content can reach more than 47.4%. However, in the traditional fused magnesium smelting process, this kind of magnesite concentrate powder must be pelletized before it can be used for smelting. The cost of pelletizing is generally 200 yuan / ton, and the amount of balls used per ton of fused magnesium oxide is 2.5:1.

[0004] The traditional fused magnesium oxide smelting process is to use special grade magnesite ore, which is crushed and screened by a crusher to obtain magnesite blocks with a particle size of 20mm-80mm, and then put into the furnace for power-on heating. Since the carbon dioxide generated in the smelting process must be discharged naturally, if the discharge is not smooth, it will cause splashing, posing a scalding risk to on-site workers. In addition, the bag dust collector adopts an open dust collection method, and the carbon dioxide gas discharged from the smelting is mixed with the air. The proportion of carbon dioxide gas is not large, which is not only not conducive to the recovery and utilization of carbon dioxide, but also causes environmental pollution. Summary of the invention

[0005] The object of the present invention is to provide a sub-vacuum fused magnesium oxide smelting and carbon dioxide capture and recovery system and process which can reduce costs, ensure production safety, and effectively recover carbon dioxide.

[0006] The sub-vacuum fused magnesium oxide smelting and carbon dioxide capture and recovery system of the present invention comprises a smelting mobile trolley, a furnace body, a smelting furnace barrel, a charging device, an electrode lifting mechanism, a bag dust collector, a transformer and an automatic control system, and is characterized in that it also comprises a carbon dioxide recovery system connected to the bag dust collector.

[0007] The furnace body is a tubular structure furnace body with an opening at the bottom, the bottom of the tubular structure furnace body is placed on a horizontal foundation ground, an operating platform is provided on the upper part of the tubular structure furnace body, partitions A, B and C are provided on the tubular structure furnace body, electrode mounting holes are concentrically opened from top to bottom on the operating platform, the top of the tubular structure furnace body, partition C, B and A, automatic feeding holes are also provided on both sides of the electrode mounting holes on the partition A, the partition A is arranged at the lower part of the tubular structure furnace body, so that the lower part of the tubular structure furnace body constitutes a smelting chamber, an access door is provided on the side wall of the smelting chamber, the smelting furnace barrel is placed on a smelting mobile trolley, and the smelting chamber is entered and exited through the access door, the partitions B and C are arranged at intervals in the middle of the tubular structure furnace body, the bag dust collector is placed on the upper part of the tubular structure furnace body, a smoke exhaust port is opened on the lower side wall of the tubular structure furnace body, and a smoke inlet is opened on the bag dust collector;

[0008] The electrode lifting mechanism comprises a graphite electrode, an electrode guide sleeve connected to the graphite electrode thread, and a hydraulic telescopic mechanism connected to the upper part of the electrode guide sleeve. The upper part of the hydraulic telescopic mechanism extends out of the cylindrical structure furnace body. The electrode guide sleeve and the graphite electrode are respectively inserted into the smelting furnace barrel from top to bottom through the operating platform, the upper part of the cylindrical structure furnace body, the partition C, the partition B and the partition A. A sealing device is provided between the electrode guide sleeve and the partition C and the partition B, so that a closed cylinder is formed below the middle of the cylindrical structure furnace body as a vacuum chamber. At the same time, the partition C and the partition B also serve as a limit bracket for the electrode guide sleeve. The hydraulic telescopic mechanism is connected to the transformer and the control system through a cable.

[0009] The feeding device is arranged at the lower part of the operating platform, and includes a feeding hopper, a feeding pipe and a star-shaped discharge valve arranged on the outer side of the upper part of the cylindrical structure furnace body. The star-shaped discharge valve is arranged at the lower part of the feeding hopper. One end of the feeding pipe is connected to the lower part of the feeding hopper through the star-shaped discharge valve, and the other end is connected to the smelting furnace through the automatic feeding hole on the partition A. An ash discharge port is arranged at the lower part of the dust collector, and the ash discharge port is connected to the feeding hopper of the feeding device through the ash discharge pipe and the ball valve.

[0010] The carbon dioxide recovery system includes a flue gas recovery pipe I, a flue gas recovery pipe II vacuum pump, a waste gas exhaust pipe and a carbon dioxide recovery pipe. One end of the flue gas recovery pipe I is connected to the smoke exhaust port opened on the lower side wall of the cylindrical structure furnace body, and the other end is connected to the smoke inlet 1 on the dust collector. The flue gas recovery pipe II is a Z-shaped flue gas recovery pipe. The air inlet end of the vacuum pump is connected to the air inlet of the Z-shaped flue gas recovery pipe, and the exhaust end of the vacuum pump is respectively connected to the waste gas exhaust pipe and the carbon dioxide recovery pipe through a three-way valve.

[0011] Preferably, there are three electrode mounting holes and four automatic feeding holes.

[0012] Preferably, the feeding device has two feeding hoppers, each of which is provided with two discharge ports, and there are four feeding pipes and star-shaped discharge valves. One end of the feeding pipe is connected to the star-shaped discharge valve, and the other end passes through the automatic feeding hole and is inserted into the smelting furnace barrel. There are also three electrode lifting mechanisms.

[0013] Preferably, the partition C, partition B and partition A are made of non-magnetic white steel plates, and the sealing device includes a bakelite insulating plate, a heat-resistant sealing rubber ring, a square sealing ring and a sealing filler. One end of the bakelite insulating plate is fixedly connected to the partition C and the partition B by bolts, and the other end is abutted against the outer side of the electrode guide sleeve. The heat-resistant sealing rubber ring and the square sealing ring are arranged at the lower part of the partition C, and the sealing filler is arranged between the partition C and the partition B, so that the cylindrical structure furnace body below the partition C and the partition B forms a sub-vacuum state.

[0014] Preferably, the vacuum pump is a Roots vacuum pump.

[0015] The sub-vacuum fused magnesium oxide smelting and carbon dioxide capture and recovery process of the present invention is characterized by comprising the following steps:

[0016] S1) Loading

[0017] Load the magnesite concentrate powder into two feeding hoppers, and then seal the feeding ports of the feeding hoppers;

[0018] S2) Prepare the furnace

[0019] Push the smelting furnace tube into the smelting chamber of the cylindrical structure furnace body, lay the padding layer and the broken electrodes for conduction, lower the graphite electrode to make the graphite electrode and the broken electrodes conduct, and then close the entrance and exit doors;

[0020] S3) Start-up of smelting and CO2 recovery

[0021] S3.1) Start the vacuum pump and connect the three-way valve to the exhaust pipe. At this time, the gas in the cylindrical furnace body forms a vacuum state under the action of negative pressure;

[0022] S3.2) When the vacuum degree in the cylindrical furnace reaches -0.05 MPa, the material is unloaded and the electricity is supplied. The temperature between the graphite electrode heads begins to rise. At this time, the three-way valve closes the exhaust gas pipe and opens the carbon dioxide recovery pipe;

[0023] S3.3) The smelting operation is carried out according to the fused magnesia production process. During the operation, when the temperature in the furnace reaches 2800°C, the magnesite concentrate powder begins to decompose and melt and emit carbon dioxide gas. At this time, the carbon dioxide gas is sucked into the bag filter under the action of negative pressure. The purified carbon dioxide gas is then sent to the carbon dioxide pressurized liquefaction workshop for recycling through a vacuum pump and a carbon dioxide recovery pipe.

[0024] The advantages of the present invention are:

[0025] Since the present invention is smelted under sub-vacuum conditions, during the smelting process, the carbon dioxide gas in the magnesium oxide liquid in the furnace will be forcibly sucked out, and no splashing will occur during smelting, so production safety is guaranteed. The negative pressure prevents bubbles from forming in the magnesium oxide crystals, and the product density is greatly improved. In addition, since the raw material used is magnesite concentrate, there is no need to press balls to save production costs. For every ton of fused magnesium oxide produced, 500 yuan / ton can be saved. The raw material contains more than 47.4% magnesium oxide and the harmful slag content is less than 1%. Therefore, the fused magnesium oxide crystals in the entire furnace contain more than 98% magnesium oxide.

[0026] In addition, since it is a fully sub-vacuum smelting process, 90% of the carbon dioxide gas is recovered. This smelting process has played a positive role in carbon recovery, carbon neutrality and clean production. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic structural diagram of the sub-vacuum fused magnesium oxide smelting and carbon dioxide capture and recovery system of the present invention.

[0028] Figure 2 for Figure 1 Side view of.

[0029] Figure 3 for Figure 1 DD cross-sectional view.

[0030] Figure 4 for Figure 1 Enlarged view of part I. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with the accompanying drawings.

[0032] like Figure 1-Figure 4 As shown, a sub-vacuum fused magnesium oxide smelting and carbon dioxide capture and recovery system of the present invention comprises a smelting mobile trolley 1, a furnace body, a smelting furnace barrel 2, a charging device, an electrode lifting mechanism, a bag dust collector 14, a transformer 11 and an automatic control system, characterized in that it also comprises a carbon dioxide recovery system connected to the bag dust collector 14,

[0033] The furnace body is a cylindrical structure furnace body 3 with an opening at the bottom. The bottom of the cylindrical structure furnace body 3 is placed on a horizontal foundation ground. An operating platform 4 is provided on the upper part of the cylindrical structure furnace body 3. The cylindrical structure furnace body is provided with a partition A, a partition B and a partition C. Electrode mounting holes are concentrically opened on the operating platform 4, the top of the cylindrical structure furnace body 3, the partition C, the partition B and the partition A from top to bottom. Automatic feeding holes are also provided on both sides of the electrode mounting hole on the partition A. The partition A is arranged at the lower part of the cylindrical structure furnace body 3, so that the cylindrical structure furnace body 3 The lower part constitutes a smelting chamber 7, and an access door 6 is provided on the side wall of the smelting chamber 7. The smelting furnace barrel 2 is placed on a smelting mobile trolley, and enters and exits the smelting chamber through the access door 6. The partition B and the partition C are arranged at intervals in the middle of the tubular structure furnace body 3. The bag filter 14 is placed on the upper part of the tubular structure furnace body 3. A smoke exhaust port 131 is opened on the lower side wall of the tubular structure furnace body 3, and a smoke inlet 132 is opened on the bag filter 14;

[0034] The electrode lifting mechanism includes a graphite electrode 8, an electrode guide sleeve 9 threadedly connected to the graphite electrode 8, and a hydraulic telescopic mechanism 12 connected to the upper part of the electrode guide sleeve 9. The upper part of the hydraulic telescopic mechanism 12 extends out of the tubular structure furnace body 3. The electrode guide sleeve 9 and the graphite electrode 8 are inserted into the smelting furnace barrel 2 from top to bottom through the operating platform 4, the upper part of the tubular structure furnace body 3, the partition C, the partition B and the partition A. A sealing device is provided between the electrode guide sleeve 9 and the partition C and the partition B, so that a closed cylinder is formed below the middle of the tubular structure furnace body 3 as a vacuum chamber. At the same time, the partition C and the partition B also serve as a limit bracket for the electrode guide sleeve 9. The hydraulic telescopic mechanism 12 is connected to the transformer 11 and the control system through a cable 10;

[0035] The feeding device is arranged at the lower part of the operating platform, and includes a feeding hopper 18, a feeding pipe 16 and a star-shaped discharge valve 17 arranged on the outer side of the upper part of the cylindrical structure furnace body 3. The star-shaped discharge valve 17 is arranged at the lower part of the feeding hopper 18. One end of the feeding pipe 16 is connected to the lower part of the feeding hopper 18 through the star-shaped discharge valve 17, and the other end is connected to the smelting furnace 2 through the automatic feeding hole on the partition A. An ash discharge port is arranged at the lower part of the bag filter, and the ash discharge port is connected to the feeding hopper 18 of the feeding device through the ash discharge pipe 19 and the ball valve 20.

[0036] The carbon dioxide recovery system includes a flue gas recovery pipe I13, a flue gas recovery pipe II21, a vacuum pump 22, a waste gas exhaust pipe 25 and a carbon dioxide recovery pipe 24. One end of the flue gas recovery pipe I13 is connected to a smoke exhaust port 131 opened on the lower side wall of the tubular structure furnace body 3, and the other end is connected to a smoke inlet 132 on the bag filter. The flue gas recovery pipe II21 is a Z-shaped flue gas recovery pipe. The air inlet end of the vacuum pump 22 is connected to the air inlet of the Z-shaped flue gas recovery pipe, and the exhaust end of the vacuum pump 22 is respectively connected to the waste gas exhaust pipe 25 and the carbon dioxide recovery pipe 24 through a three-way valve 23.

[0037] The present invention has three electrode mounting holes and four automatic feeding holes.

[0038] Preferably, the feeding device has two feeding hoppers 18, each of which has two discharge ports, the feeding pipes 16 and the star-shaped discharge valves 17 are four, one end of the feeding pipe 16 is connected to the star-shaped discharge valve 17, and the other end passes through the automatic feeding hole and is inserted into the smelting furnace 2, and the electrode lifting mechanism is also three, such as Figure 3 shown.

[0039] The partition C, partition B and partition A described in the present invention are made of non-magnetic white steel plates, and the sealing device includes a bakelite insulating plate 51, a heat-resistant sealing rubber ring 52, a square sealing ring 53 and a sealing filler 54. One end of the bakelite insulating plate 51 is fixedly connected to the partition C and the partition B by bolts, and the other end is in contact with the outer side of the electrode guide sleeve 9, so that the conductive copper tube in the electrode guide sleeve is insulated from the partition C and the partition B. The heat-resistant sealing rubber ring 52 and the square sealing ring 53 are arranged at the lower part of the partition C, and the sealing filler is arranged between the partition C and the partition B, so that the cylindrical structure furnace body 3 below the partition C and the partition B forms a sub-vacuum state, such as Figure 4 shown.

[0040] The sub-vacuum fused magnesium oxide smelting and carbon dioxide capture and recovery process of the present invention is characterized by comprising the following steps:

[0041] S1) Loading

[0042] The magnesite concentrate powder is loaded into two feeding hoppers 18, and then the feeding ports of the feeding hoppers are closed;

[0043] S2) Prepare the furnace

[0044] Push the smelting furnace tube 2 into the smelting chamber 7 of the cylindrical structure furnace body 3, lay the cushion layer 27 and the broken electrode 26 for conduction, lower the graphite electrode 8 to make the graphite electrode 8 and the broken electrode 26 conduct, and then close the access door 6;

[0045] S3) Start-up of smelting and CO2 recovery

[0046] S3.1) Start the vacuum pump 22, and at the same time connect the three-way valve to the exhaust pipe. At this time, the gas in the cylindrical furnace body forms a vacuum state under the action of negative pressure;

[0047] S3.2) When the vacuum degree in the cylindrical furnace reaches -0.05 MPa, the material is unloaded and the electricity is supplied. The temperature between the graphite electrode heads begins to rise. At this time, the three-way valve closes the exhaust gas pipe and opens the carbon dioxide recovery pipe;

[0048] S3.3) The smelting operation is carried out according to the fused magnesia production process. During the operation, when the temperature in the furnace reaches 2800°C, the magnesite concentrate powder begins to decompose and melt and discharge carbon dioxide gas. At this time, the carbon dioxide gas is sucked into the bag filter 14 under the action of negative pressure. The purified carbon dioxide gas is then sent to the carbon dioxide pressurized liquefaction workshop for recycling through the vacuum pump 22 and the carbon dioxide recovery pipe 24.

[0049] The dust discharge port of the bag filter of the present invention is connected to the two feeding hoppers 18 respectively by a ball valve. The vacuum pump is a Roots vacuum pump. The purified carbon dioxide gas is sent to the carbon dioxide pressurized liquefaction workshop by the Roots vacuum pump. The Roots vacuum pump is also a sub-vacuum main fan. The air volume is five times the hourly output of carbon dioxide gas, and the vacuum pressure is -0.05 MPa.

[0050] The smelting automatic control system of the present invention adopts the existing automatic control system, and its vacuum pump, ball valve, star-shaped ash discharge valve and transformer are all connected to the automatic control system. At the same time, the electrode lifting mechanism automatically lifts the graphite electrode as the refining liquid level in the furnace rises.

[0051] Since the entire production process of the present invention is carried out in a closed state, it is a sub-vacuum smelting. The gas in the magnesium oxide liquid in the furnace will be forced to be sucked out, and there will be no splashing during smelting, so the production safety is guaranteed. The negative pressure prevents bubbles from appearing in the magnesium oxide crystals, and the product density is greatly improved. Since the raw material used is magnesite concentrate, there is no need to press balls to save production costs. For every ton of fused magnesium oxide produced, 500 yuan / ton can be saved. The raw material contains more than 47.4% magnesium oxide and the content of harmful slag is less than 1%. Therefore, the fused magnesium oxide crystals in the whole furnace contain more than 98% magnesium oxide. In addition, since it is a full sub-vacuum smelting, 90% of carbon dioxide gas is recovered. This smelting process has played a positive role in promoting carbon recovery, carbon neutralization, and clean production.

Claims

1. A sub-vacuum fused magnesium oxide smelting and carbon dioxide capture and recovery process, characterized in that: The sub-vacuum fused magnesium oxide smelting and carbon dioxide capture and recovery system is adopted, including a smelting mobile trolley, a furnace body, a smelting furnace barrel, a charging device, an electrode lifting mechanism, a bag dust collector, a transformer and an automatic control system, and also includes a carbon dioxide recovery system connected to the bag dust collector. The furnace body is a tubular structure furnace body with an opening at the bottom, the bottom of the tubular structure furnace body is placed on a horizontal foundation ground, an operating platform is provided on the upper part of the tubular structure furnace body, partitions A, B and C are provided on the tubular structure furnace body, electrode mounting holes are concentrically opened from top to bottom on the operating platform, the top of the tubular structure furnace body, partition C, B and A, automatic feeding holes are also provided on both sides of the electrode mounting holes on the partition A, the partition A is arranged at the lower part of the tubular structure furnace body, so that the lower part of the tubular structure furnace body constitutes a smelting chamber, an access door is provided on the side wall of the smelting chamber, the smelting furnace barrel is placed on a smelting mobile trolley, and the smelting chamber is entered and exited through the access door, the partitions B and C are arranged at intervals in the middle of the tubular structure furnace body, the bag dust collector is placed on the upper part of the tubular structure furnace body, a smoke exhaust port is opened on the lower side wall of the tubular structure furnace body, and a smoke inlet is opened on the bag dust collector; The electrode lifting mechanism comprises a graphite electrode, an electrode guide sleeve connected to the graphite electrode thread, and a hydraulic telescopic mechanism connected to the upper part of the electrode guide sleeve. The upper part of the hydraulic telescopic mechanism extends out of the cylindrical structure furnace body. The electrode guide sleeve and the graphite electrode are respectively inserted into the smelting furnace barrel from top to bottom through the operating platform, the upper part of the cylindrical structure furnace body, the partition C, the partition B and the partition A. A sealing device is provided between the electrode guide sleeve and the partition C and the partition B, so that a closed cylinder is formed below the middle of the cylindrical structure furnace body as a vacuum chamber. At the same time, the partition C and the partition B also serve as a limit bracket for the electrode guide sleeve. The hydraulic telescopic mechanism is connected to the transformer and the control system through a cable. The feeding device is arranged at the lower part of the operating platform, and includes a feeding hopper, a feeding pipe and a star-shaped discharge valve arranged on the outer side of the upper part of the cylindrical structure furnace body. The star-shaped discharge valve is arranged at the lower part of the feeding hopper. One end of the feeding pipe is connected to the lower part of the feeding hopper through the star-shaped discharge valve, and the other end is connected to the smelting furnace through the automatic feeding hole on the partition A. An ash discharge port is arranged at the lower part of the dust collector, and the ash discharge port is connected to the feeding hopper of the feeding device through the ash discharge pipe and the ball valve. The carbon dioxide recovery system comprises a flue gas recovery pipe I, a flue gas recovery pipe II vacuum pump, a waste gas exhaust pipe and a carbon dioxide recovery pipe. One end of the flue gas recovery pipe I is connected to a smoke exhaust port opened on the lower side wall of the tubular structure furnace body, and the other end is connected to a smoke inlet on the dust collector. The flue gas recovery pipe II is a Z-shaped flue gas recovery pipe. The air inlet end of the vacuum pump is connected to the air inlet of the Z-shaped flue gas recovery pipe. The exhaust end of the vacuum pump is connected to the waste gas exhaust pipe and the carbon dioxide recovery pipe through a three-way valve. The process includes the following steps: S1) Loading Load the magnesite concentrate powder into two feeding hoppers, and then close the feeding port of the feeding hopper; S2) Furnace preparation Push the smelting furnace tube into the smelting chamber of the cylindrical structure furnace body, lay the padding layer and the broken electrodes for conduction, lower the graphite electrode to make the graphite electrode and the broken electrodes conduct, and then close the entrance and exit doors; S3) Start-up of smelting and CO2 recovery S3.1) Start the vacuum pump and connect the three-way valve to the exhaust pipe. At this time, the gas in the cylindrical furnace body forms a vacuum state under the action of negative pressure; S3.2) When the vacuum degree in the cylindrical furnace reaches -0.05 MPa, the material is unloaded and the electricity is supplied. The temperature between the graphite electrode heads begins to rise. At this time, the three-way valve closes the exhaust gas pipe and opens the carbon dioxide recovery pipe; S3.3) The smelting operation is carried out according to the fused magnesia production process. During the operation, when the temperature in the furnace reaches 2800°C, the magnesite concentrate powder begins to decompose and melt and emit carbon dioxide gas. At this time, the carbon dioxide gas is sucked into the bag filter under the action of negative pressure. The purified carbon dioxide gas is then sent to the carbon dioxide pressurized liquefaction workshop for recycling through a vacuum pump and a carbon dioxide recovery pipe.

2. The sub-vacuum fused magnesium oxide smelting and carbon dioxide capture and recovery process according to claim 1, characterized in that: The number of the electrode installation holes is three, and the number of the automatic feeding holes is four.

3. The sub-vacuum fused magnesium oxide smelting and carbon dioxide capture and recovery process according to claim 2, characterized in that: The feeding device has two feeding hoppers, each of which is provided with two discharge ports. There are four feeding pipes and star-shaped discharge valves. One end of the feeding pipe is connected to the star-shaped discharge valve, and the other end passes through the automatic feeding hole and is inserted into the smelting furnace barrel. There are also three electrode lifting mechanisms.

4. The sub-vacuum fused magnesium oxide smelting and carbon dioxide capture and recovery process according to claim 1, characterized in that: The partition C, partition B and partition A are made of non-magnetic white steel plates, and the sealing device includes a bakelite insulating plate, a heat-resistant sealing rubber ring, a square sealing ring and a sealing filler. One end of the bakelite insulating plate is fixedly connected to the partition C and the partition B by bolts, and the other end is abutted against the outer side of the electrode guide sleeve. The heat-resistant sealing rubber ring and the square sealing ring are arranged at the lower part of the partition C, and the sealing filler is arranged between the partition C and the partition B, so that the cylindrical structure furnace body below the partition C and the partition B forms a sub-vacuum state.

5. The sub-vacuum fused magnesium oxide smelting and carbon dioxide capture and recovery process according to claim 1, characterized in that: The vacuum pump is a Roots vacuum pump.

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