Raw material feeding device and method based on molten pool magnesium smelting

Abstract

The invention discloses a raw material feeding device and method based on molten pool magnesium smelting, and relates to the technical field of magnesium smelting. The invention provides a raw material feeding device based on molten pool magnesium smelting. The raw material feeding device comprises a first-stage feeding system, a second-stage feeding system, an air sealing system and a Venturi jet system. The air seal machine is arranged to be introduced into the air seal system, the continuous discharging speed of the materials is effectively controlled, and the production period is further shortened. And the material of the Venturi tube is adjusted, so that the service life of the Venturi tube is greatly prolonged. When the raw material feeding device is adopted for feeding, raw materials are fully mixed in the feeding bin before entering a molten pool to react, the situation that reduction is incomplete due to insufficient mixing of the materials is avoided, the oxygen monitoring device is added, and the situation that oxygen introduced in the operation process interferes with the reduction result is greatly avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of magnesium smelting, and in particular to a raw material feeding device and method based on molten pool magnesium smelting. Background Art

[0002] Molten pool magnesium smelting, as an important magnesium smelting technology, plays a key role in modern industrial production. With the continued development of the global economy and the increasing demand for magnesium and magnesium alloys across various industries, the application of molten pool magnesium smelting technology is becoming increasingly broad, covering a wide range of fields such as aerospace, automotive manufacturing, and electronic communications. However, in the current pursuit of efficient and high-quality production, existing molten pool magnesium smelting technology faces many severe challenges, among which the performance of the feed device has become a key bottleneck restricting the further development of the industry.

[0003] In traditional molten pool magnesium smelting feeding devices, due to the limitations of structural design and working principles, it is impossible to achieve uniform and stable transportation of materials. This results in the raw materials not being able to fully and evenly participate in the reaction during the molten pool reaction, and a large amount of raw materials are accumulated in local areas, while other areas are short of raw materials, which greatly reduces the magnesium extraction rate. For example, in some devices that use gravity self-flow feeding, the material is prone to blockage or accumulation in the conveying pipeline due to its own characteristics (such as uneven particle size distribution, humidity differences, etc.), causing the feed flow rate to be large and small, seriously affecting the stability and continuity of the molten pool reaction. According to relevant statistical data, the reduction in magnesium extraction rate due to uneven feeding can reach 10%-20%, which not only causes a huge waste of raw materials, but also significantly increases production costs.

[0004] Existing feeding devices make it difficult to achieve precise proportioning and uniform mixing of multiple raw materials and binders. In the process of molten pool magnesium smelting, different magnesium ore raw materials (such as dolomite, magnesite, brucite, etc.) and binders (such as fluorite, water glass, etc.) need to be mixed in specific proportions to ensure the sufficiency of the reaction and the quality stability of the product. However, traditional devices often lack precise metering and mixing means, and can only rely on manual experience for rough proportioning and simple stirring, which cannot meet the high precision and high quality requirements of modern industrial production. This imprecise proportioning and mixing method can easily lead to incomplete reaction and the generation of impurities, which in turn affects the purity and performance of magnesium products. For example, in some actual production cases, due to inaccurate raw material proportioning, the impurity content in magnesium products exceeds the standard, which cannot meet the quality standards of high-end application fields, and the market competitiveness of the products is greatly reduced.

[0005] During the feeding process, existing devices generally lack effective gas protection measures. Magnesium ore raw materials have certain chemical activity at room temperature and are prone to chemical reactions with oxygen, moisture, etc. in the air, causing the raw materials to deteriorate. During the feeding process, when the raw materials are exposed to the air, this deterioration phenomenon will become more serious, which will directly affect the product quality of the molten pool magnesium smelting. For example, some raw materials will undergo oxidation reactions after contact with oxygen to generate oxide impurities. These impurities are difficult to remove in the molten pool reaction and will remain in the final product, reducing the purity of the magnesium. In addition, the presence of moisture will also affect the physical properties of the raw materials, such as fluidity and adhesion, which in turn affects the stability of the feed and the progress of the reaction. Therefore, the lack of effective gas protection measures has become a major shortcoming of existing feeding devices and needs to be solved urgently.

[0006] Patent CN119980367A discloses an automatic feeding / discharging system for a magnesium electrolytic cell and its use method. The automatic feeding / discharging system is controlled by a magnesium layer thickness measurement unit, a magnesium layer liquid level measurement unit, a first electric valve, a second electric valve, an argon gas component, a vacuum component, and a distributed control system. This invention reduces labor and improves production efficiency by changing the traditional manual feeding and discharging methods. It can save a lot of labor, improve electrolysis efficiency, and improve product quality and equipment life. However, this equipment has certain limitations. Its scope of use is limited to electrolytic magnesium smelting and is not suitable for the pyrometallurgical magnesium smelting industry, which accounts for more than 90% of the industry's use. Patent CN119824247A provides a device and method for conveying balls for magnesium refining in a vertical tank. A high-angle conveyor belt for transporting balls from a low location to a high location is installed at the end of the ball conveyor belt line away from the briquette press. A flat belt line for horizontally conveying balls is installed at the end of the high-angle conveyor belt away from the ball conveyor belt line. A forked material receiver for packing the balls is provided at the end of the flat belt line away from the high-angle conveyor belt. A silo is provided below the forked material receiver. A transport assembly for transporting the silo is provided below the silo. The transport assembly, forked material receiver, and silo are arranged in the reduction workshop. This invention can effectively reduce the transportation distance of the balls within the silo, effectively reduce the breakage rate of the balls, and effectively improve the efficiency of loading the balls into the vertical tank of the reduction furnace. However, the device is based on spherical raw materials, that is, the raw materials still need to go through the step of ball pressing. This device and method still do not solve the problem of the long production cycle of magnesium metal. Patent CN111321310B discloses a method and system for preparing metallic magnesium. The preparation method comprises: melting a reducing agent or a mixture of a reducing agent and a flux to obtain a reducing liquid; spraying forging white or a mixture of forging white and a flux into the reducing liquid for reduction treatment to obtain magnesium-containing fume, metal melt, and smelting slag. This method can achieve continuous reduction smelting of metallic magnesium under normal pressure or positive pressure, but the method has high requirements for raw materials and cannot directly utilize magnesium-containing ores. The raw material feeding method is relatively fragmented, which may result in uneven mixing. Patent CN111270088A discloses a system and method for continuous magnesium smelting using induction heating and liquid stirring. The system comprises: ferrosilicon, magnesium ore, and flux raw material silos, each raw material silo having an inert gas inlet and a vacuum port; a feeding mechanism; a feed pipe extending to the outside of the enclosed room and connected to a screw conveyor, and a flue gas pipe extending to the outside of the enclosed room. The system operates at slightly negative pressure or normal pressure, enabling continuous feeding and discharging, enabling continuous production of magnesium metal and reducing production costs. It can also effectively reduce splashing and smoke content, improve the quality of raw magnesium, and ensure stable equipment operation.However, the feeding method of this equipment is a screw conveyor feeding, which cannot guarantee the uniformity of raw material mixing. The equipment needs to add a stirring paddle for mixing or stirring, which further increases the mechanical strength. At the same time, the spiral feeding mechanism cannot guarantee that the system is in an oxygen-free state after vacuuming.

[0007] Existing technologies usually improve the fluidity and uniformity of material delivery by improving the structure and material of the feed pipe; advanced metering equipment and mixing technology are used to achieve accurate proportioning and uniform mixing of raw materials. However, these improvement measures often have certain limitations. On the one hand, the stability and reliability of the improved device in actual production still need to be improved, and it is easily affected by various factors and malfunctions; on the other hand, the cost of these improvement measures is relatively high, which increases the production cost of enterprises and limits their widespread application in the industry. In addition, with regard to the issue of gas protection, although some companies have tried to introduce a small amount of protective gas during the feeding process, due to the lack of systematic design and effective control methods, it is impossible to achieve a comprehensive and stable gas protection effect.

[0008] Therefore, existing attempts at technical improvement cannot fundamentally solve the problems existing in the molten pool magnesium smelting feeding device. There is an urgent need for a new and more advanced feeding device to meet the needs of industry development. Summary of the Invention

[0009] The present invention provides a raw material feeding device based on molten pool magnesium smelting, which improves the stability and reliability of the molten pool magnesium smelting device in a low-cost manner and simultaneously achieves a comprehensive and stable gas protection effect.

[0010] The present invention adopts the following technical solutions:

[0011] A raw material feeding device based on molten pool magnesium smelting includes a primary feeding system, a secondary feeding system, an air shutoff system and a Venturi jet system; wherein the Venturi jet system includes a Venturi tube and a throat ejector made of a special material provided at its throat; the air shutoff system includes a primary air shutoff and a secondary air shutoff;

[0012] The primary feeding system is located above the secondary feeding system and is connected to the secondary feeding system through a pipeline provided with a primary air lock; the secondary feeding system is connected to the throat of the venturi tube through a pipeline, and the secondary air lock is provided on the pipeline between the secondary feeding system and the throat of the venturi tube in the venturi jet system;

[0013] The first-level feeding system includes two first-level feeding bins with identical structures; a material grinder is provided in the middle of the first-level feeding bin, and a weight metering device is provided below the material grinder; after the raw materials are ground by the material grinder, they fall into the weight metering device for weighing, and the flow of the materials is controlled before entering the first-level air lock;

[0014] The secondary feeding system includes a secondary feeding silo and a primary stirring system arranged in the secondary feeding silo; the secondary feeding silo has a transmission shaft as its central axis, and a fan-bladed stirring paddle on the transmission shaft; the transmission shaft and the fan-bladed stirring paddle constitute the primary stirring system; an inert gas inlet I is provided at one end of the secondary feeding silo; an oxygen monitor is also provided at the outlet of the secondary feeding silo; the primary stirring system further grinds the material while stirring the material;

[0015] The outlet of the secondary feed bin is sequentially connected to a secondary air lock, a secondary stirring system, and a venturi tube through a pipeline;

[0016] The two ends of the venturi tube are respectively provided with an inert gas inlet II and a material and inert gas outlet, and the material and inert gas outlet are sealedly connected to the molten pool; after the material enters the venturi tube, the inert gas entering the venturi tube through the inert gas inlet II is sprayed into the molten pool from the throat ejector inlet;

[0017] The inert gas inlet II is connected to an inert gas recovery and circulation device and is equipped with a gas compression and reflux supply system. The inert gas is recycled through the inert gas recovery and circulation device.

[0018] The first-stage air lock and the second-stage air lock are impeller-type structures, and the material flow is precisely controlled by electronic control;

[0019] The throat ejector and the venturi tube throat to the connection with the molten pool are made of the same material, which is hard alloy, including one of cast iron, steel-connected hard alloy, metal ceramic, nickel-based alloy, and tungsten-molybdenum alloy; the metal ceramic is tungsten carbide or titanium carbide.

[0020] The throat ejector is a patch provided at the throat of the venturi tube, wherein the patch has a thickness of 0.5 mm to 3 mm;

[0021] The inner surfaces of the throat ejector and the venturi tube from the throat to the connection with the molten pool are electroplated or sprayed with a wear-resistant coating.

[0022] A raw material feeding method based on molten pool magnesium smelting is implemented using the above-mentioned device, comprising the following steps:

[0023] Step 1. Coarsely grinding the magnesium-containing raw material, reducing agent and flux respectively;

[0024] Step 2. Add the coarsely ground reducing agent to the molten pool and start induction heating to heat the molten pool; add the coarsely ground magnesium-containing raw material and flux raw material to two primary feed bins respectively;

[0025] Step 3. The magnesium-containing raw material and flux are ground in a material grinder and then dropped into a weight metering device for weighing to control the material volume flow rate;

[0026] Step 4. Open the first-stage air lock outlet, and the material enters the second-stage feed bin through the first-stage air lock;

[0027] Step 5. The magnesium-containing raw material and flux are stirred in the secondary feeding bin by the primary stirring system, further ground and mixed, and then enter the secondary stirring system through the secondary air lock;

[0028] Step 6. The mixed materials after further grinding are further mixed by stirring in a secondary stirring system and fall into the throat of the venturi tube;

[0029] Step 7. After the material enters the venturi tube, the inert gas entering the venturi tube through the inert gas inlet II is sprayed from the throat ejector inlet into the molten pool;

[0030] Step 8. The material undergoes a reduction reaction with the molten reducing agent in the molten pool. The metallic magnesium vapor generated during the reduction process is collected through a condenser and further refined and purified. The tailings generated during the reduction smelting process are further harmlessly treated.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1. The raw materials are fully mixed in the feed bin before entering the molten pool for reaction, which avoids incomplete reduction caused by insufficient material mixing. The addition of an oxygen monitoring device greatly avoids the oxygen introduced during the operation from interfering with the reduction results and even causing production safety problems.

[0033] 2. The introduction of the air lock device is different from the traditional feeding process of first breaking the vacuum and then pumping the vacuum again. It effectively controls the continuous feeding speed of the material and further shortens the production cycle.

[0034] 3. The innovative introduction of the Venturi jet system increases the local air pressure, making the migration effect of the inert gas carrying magnesium vapor more excellent.

[0035] 4. Due to the large feed volume of magnesium-containing materials, the tube body will be worn when entering the Venturi tube. Therefore, the material of the Venturi tube has been adjusted, which greatly enhances the service life of the Venturi tube and reduces the time waste and equipment investment waste caused by frequent replacement of the Venturi tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a structural diagram of a raw material feeding device based on molten pool magnesium smelting;

[0037] Figure numerals: 1-primary feed bin, 2-material grinder, 3-weight metering device, 4-primary air lock, 5-inert gas inlet I, 6-secondary feed bin, 7-primary stirring system, 8-oxygen monitor, 9-secondary air lock, 10-secondary stirring system, 11-inert gas inlet II, 12-throat ejector, 13-Venturi tube, 14-material and inert gas outlet. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to illustrate the present invention, and the scope of protection of the present invention is not limited to the contents described.

[0039] When feeding the raw material feeding device for magnesium smelting in a molten pool, the first step is to check the tightness of the connections between the components to ensure good sealing performance and prevent air from entering the feeding system and affecting the relative vacuum system. The feeding device is tested for airtightness. If any leaks are found, the leaks are promptly located and repaired.

[0040] Select appropriate fluxes, such as one or more of calcium fluoride, sodium fluoride, potassium fluoride, and magnesium fluoride, as well as reducing agents and magnesium ore raw materials. Strict quality testing is performed on the selected raw materials to ensure their purity and composition meet process requirements.

[0041] The flux, reducing agent and magnesium ore raw materials are crushed separately. According to the reaction requirements, the particle size distribution of the raw materials is controlled to make the particle size uniform in order to increase the contact area and reaction rate of the reaction.

[0042] Feed the magnesium-containing material and flux material into the first-level feed bin slowly and evenly. During the feeding process, avoid material accumulation or blocking the feed port to ensure that the materials can enter the first-level feed bin smoothly.

[0043] A material grinder is installed in the first-level feed bin to further grind the material to make the particle size of the material more uniform; at the same time, a weight measuring device is installed in the first-level feed bin to control the quality of the material.

[0044] After passing through the first-stage feed bin, the material enters the first-stage air lock, where the first-stage air lock serves to isolate oxygen and other gases that interfere with the reaction.

[0045] The materials pass through the primary air lock and enter the secondary feed hopper, which features a well-sealed structure. The secondary feed hopper houses a primary stirring system connected to its outlet, which stirs and grinds the magnesium-containing raw materials and binder to a particle size and uniformity suitable for smelting in the molten pool. A secondary air lock is located below the secondary feed hopper. Both the primary and secondary air locks are impeller-type, and electronically controlled to precisely control material flow.

[0046] An oxygen monitor is installed at the outlet of the secondary feeding bin, which is used to detect whether there is oxygen mixed in during the feeding process. Below it is connected to a secondary air shutoff device and a secondary stirring system, where the secondary stirring system plays the role of further mixing the materials.

[0047] A throat ejector made of special material is installed at the throat of the venturi tube and connected to the lower part of the secondary mixing system. One end of the venturi tube is connected to the inert gas inlet II, and the other end is provided with material and inert gas outlets to achieve efficient transportation of material and inert gas.

[0048] Inert gas inlet II is connected to an inert gas recovery and circulation device and equipped with a comprehensive inert gas supply system capable of gas compression and reflux, allowing the inert gas to be recycled, significantly reducing production costs. The inert gas supply system is used to provide inert gas protection during the feeding process, preventing material oxidation and contamination of the reaction environment. The inert gas used for injection is circulated, further purified, and then re-entered the argon injection cycle through a circulation pump, achieving gas recycling. During the circulation process, the inert gas is purity tested and impurities removed to ensure its continued and effective protection.

[0049] The first-level feed bin provided by the present invention is made of special materials and its capacity is reasonably designed, which can store magnesium-containing raw materials and flux respectively; the first-level feed bin is connected to the second-level feed bin through a discharge pipe. The first-level feed bin has good sealing performance; a material grinder and a weighing and weighing system are provided inside, and the material grinder is driven by a high-performance motor and a precision transmission device, and adopts a rotating roller structure, which can accurately control the grinding particle size. Before the raw materials passing through the first-level feed bin enter the second-level feed bin, they are first ground and crushed, and then accurately weighed and measured; the lower part of the first-level feed bin is connected to the first-level air shutoff, and the function of the first-level air shutoff here is to control the feeding rate and isolate the gas; the lower end of the first-level air shutoff is connected to the second-level feed bin, wherein a first-level stirring system is provided in the second-level feed bin, and a fan-blade stirring paddle is provided inside the first-level feed system to ensure the uniformity of the mixing during the transmission process; the discharge port of the second-level feed bin is equipped with an oxygen monitor, which can effectively monitor the gas content inside the feeding system, especially the oxygen content inside the monitoring system. When oxygen is mixed in, the reducing substances in the oxygen monitor and the oxygen Gas reaction, to prevent oxygen from mixing into the smelting device during the feeding process and causing oxidation of the reduced steam magnesium; a secondary air lock is connected below the oxygen monitor, which is an impeller-type structure and realizes precise control of the material flow through electronic control; the secondary air lock is connected below the secondary stirring system, which further mixes the material and then transports it to the venturi tube connected below. The venturi tube has a special throat structure and is equipped with a throat ejector; an inert gas inlet II is provided at one end of the venturi tube, which adopts a special distributor structure and is equipped with a complete supply system; a material and inert gas outlet is provided at the other end of the venturi tube, which is connected to the molten pool and is equipped with multiple safety protections, which can realize efficient transportation of materials and inert gas. The raw material feeding device based on molten pool magnesium smelting provided by the present invention can realize accurate feeding and proportioning, uniformly mix raw materials, and feed under the protection of inert gas, effectively improving the production efficiency of molten pool magnesium smelting, reducing costs, and improving product quality.

[0050] The throat ejector and the venturi tube throat to the connection with the molten pool in the present invention are made of the same material, which is hard alloy, including one of cast iron, steel-connected hard alloy, metal ceramic, nickel-based alloy, and tungsten-molybdenum alloy; the metal ceramic is tungsten carbide or titanium carbide.

[0051] The throat ejector of the present invention is a patch with a thickness of 0.5mm to 3mm set at the throat of the venturi tube. The inner surface of the throat ejector and the part from the throat of the venturi tube to the connection with the molten pool is electroplated or sprayed with a wear-resistant coating.

[0052] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0053] Example 1:

[0054] This embodiment provides a raw material feeding device based on molten pool magnesium smelting, such as Figure 1As shown, it includes a primary feeding system, a secondary feeding system, an air shutoff system, and a Venturi jet system; wherein the Venturi jet system includes a Venturi tube 13 and a throat ejector 12 provided at its throat; the air shutoff system includes a primary air shutoff 4 and a secondary air shutoff 9. The primary feeding system is located above the secondary feeding system and is connected to the secondary feeding system via a pipe provided with the primary air shutoff; the secondary feeding system is connected to the throat of the Venturi tube 13 via a pipe, and the secondary air shutoff 9 is provided on the pipe between the secondary feeding system and the throat of the Venturi tube 13 in the Venturi jet system. The 0.5mm to 3mm patch provided at the throat of the Venturi tube 13 is the throat ejector 12. The throat ejector 12 and the inner surface of the throat ejector 12 and the part from the throat of the Venturi tube 13 to the connection with the molten pool are electroplated or sprayed with a wear-resistant coating.

[0055] The first-level feeding system includes two first-level feeding bins 1 with exactly the same structure; a material grinder 2 is provided in the middle of the first-level feeding bin 1, and a weight metering device 3 is provided below the material grinder 2; after the raw materials are ground by the material grinder 2, they fall into the weight metering device 3 for weighing, control the flow of the materials, and enter the first-level air lock 4.

[0056] The secondary feeding system includes a secondary feeding silo 6 and a primary stirring system 7 disposed within the silo. The silo 6 is centered around a drive shaft, which is equipped with a paddle. The drive shaft and paddle constitute the primary stirring system 7. An inert gas inlet 15 is located at one end of the silo 6. An oxygen monitor 8 is also located at the outlet of the silo. The primary stirring system 7 further grinds the material while stirring it. The outlet of the silo 6 is connected to a secondary air lock 9, a secondary stirring system 10, and a venturi tube 13 via pipes.

[0057] The venturi tube 13 is equipped with an inert gas inlet II 11 and a material and inert gas outlet 14 at each end. The material and inert gas outlet 14 is sealed to the molten pool. After the material enters the venturi tube 13, the inert gas enters the venturi tube 13 through the inert gas inlet II 11 and is sprayed into the molten pool from the inlet of the throat ejector 12. The inert gas inlet II 11 is connected to an inert gas recovery and circulation device, equipped with a comprehensive gas compression and reflux supply system to ensure the recycling of the inert gas.

[0058] The first-stage air lock 4 and the second-stage air lock 9 are impeller-type structures, and precise control of material flow is achieved through electronic control.

[0059] This embodiment also provides a raw material feeding method based on molten pool magnesium smelting, which is implemented using the above-mentioned device and includes the following steps:

[0060] Step 1. Grind one or more of calcium fluoride, sodium fluoride, potassium fluoride, and magnesium fluoride as fluxes into fine particles with a diameter of 100 to 300 μm. Grind magnesium-containing raw materials such as dolomite, magnesite, and brucite into fine particles with a diameter of 100 to 300 μm. Grind reducing agents such as #75 ferrosilicon, Si, Al, and aluminum alloys into fine particles with a diameter of 10 to 300 μm.

[0061] Step 2. Add the coarsely ground reducing agent into the molten pool, start induction heating, and heat the molten pool; add the coarsely ground magnesium-containing raw material flux raw material into the two primary feed bins 1 respectively.

[0062] Step 3. After the magnesium-containing material and the flux are ground by the material grinder 2, they fall into the weight metering device 3 for weighing, and the volume flow rate of the material is controlled at 0.1 L / min to 2 L / min.

[0063] Step 4. Open the outlet of the first-level air lock 4 to allow the flux and magnesium-containing raw materials to enter the second-level feed bin 6.

[0064] Step 5. The flux and the magnesium-containing raw material are stirred and further finely ground in the secondary feeding bin 6 through the primary stirring system 7 and then enter the secondary stirring system 10 through the secondary air lock 9.

[0065] Step 6. The finely ground material is further mixed by the secondary mixing system 10. The material volume flow rate is controlled between 0.1L / min and 2L / min, and the particle size is fine, ranging from 10μm to 300μm. The mixed material enters the throat ejector 12. The material volume flow rate is controlled between 0.1L / min and 2L / min. Simultaneously, the inert gas inlet valve II 11 is opened, allowing inert gas to enter the throat ejector 12, which is made of high-carbon, high-chromium cast iron. The material from the throat of the venturi tube 13 to its connection with the molten pool is the same as that of the throat ejector 12.

[0066] Step 7. Control the inert gas flow rate at the inert gas inlet II 11 end of the venturi tube 13 to 0.1m 3 / h~3m 3 / h, during which the jet velocity of the material during the argon blowing process is ensured to be 0.1m / s~2m / s.

[0067] Step 8. The material undergoes a reduction reaction with the molten reducing agent in the molten bath. The metallic magnesium vapor generated during the reduction process is collected through a condenser and subsequently further refined and purified. The tailings generated during the reduction smelting process are further harmlessly treated.

[0068] Example 2:

[0069] This embodiment provides a raw material feeding method based on molten pool magnesium smelting, which is implemented using the device in Example 1 and includes the following steps:

[0070] Step 1. Coarsely grind one or more fluxes, such as calcium fluoride, sodium fluoride, potassium fluoride, and magnesium fluoride, into fine particles with a diameter of 20 to 200 μm. Coarsely grind magnesium-containing raw materials, such as dolomite, magnesite, and brucite, into fine particles with a diameter of 20 to 200 μm. Coarsely grind reducing agents, such as #75 ferrosilicon, Si, Al, and aluminum alloys, into fine particles with a diameter of 20 to 200 μm.

[0071] Step 2. Add the coarsely ground reducing agent into the molten pool, start induction heating, and heat the molten pool; add the coarsely ground magnesium-containing raw material flux raw material into the two primary feed bins 1 respectively.

[0072] Step 3. After the magnesium-containing material and the flux are ground by the material grinder 2 respectively, they fall into the weight metering device 3 for weighing, and the volume flow rate of the material is controlled at 0.2 L / min to 1.8 L / min.

[0073] Step 4. Open the outlet of the first-level air lock 4 to allow the flux and magnesium-containing raw materials to enter the second-level feed bin 6.

[0074] Step 5. The flux and the magnesium-containing raw material are stirred in the secondary feeding bin 6 by the primary stirring system 7, the material is further finely ground, and enters the secondary stirring system 10 through the secondary air lock 9.

[0075] Step 6. The finely ground material is further mixed by the secondary stirring system 10. The material volume flow rate is controlled between 0.2L / min and 1.8L / min, and the particle size is fine, ranging from 20μm to 200μm. The mixed material enters the throat ejector 12. The material volume flow rate is controlled between 0.2L / min and 1.8L / min. Simultaneously, the inert gas inlet valve II 11 is opened, allowing inert gas to enter the tungsten carbide cermet throat ejector 12. The material from the throat of the venturi tube 13 to its connection with the molten pool is the same as that of the throat ejector 12.

[0076] Step 7. Control the inert gas flow rate at the inert gas inlet II 11 end of the venturi tube 13 to 0.2m 3 / h~2.8m 3 / h, during which the jet velocity of the material during the inert gas blowing is ensured to be 0.2m / s~1.8m / s.

[0077] Step 8. The material undergoes a reduction reaction with the molten reducing agent in the molten bath. The metallic magnesium vapor generated during the reduction process is collected through a condenser and subsequently further refined and purified. The tailings generated during the reduction smelting process are further harmlessly treated.

[0078] Example 3:

[0079] This embodiment provides a raw material feeding method based on molten pool magnesium smelting, which is implemented using the device in Example 1 and includes the following steps:

[0080] Step 1. Coarsely grind one or more fluxes (calcium fluoride, sodium fluoride, potassium fluoride, and magnesium fluoride) into fine particles with a diameter of 30 to 100 μm. Coarsely grind magnesium-containing raw materials (such as dolomite, magnesite, and brucite) into fine particles with a diameter of 30 to 100 μm. Coarsely grind reducing agents (such as #75 ferrosilicon, Si, Al, and aluminum alloy) into fine particles with a diameter of 30 to 100 μm.

[0081] Step 2. Add the coarsely ground reducing agent into the molten pool, start induction heating, and heat the molten pool; add the coarsely ground magnesium-containing raw material flux raw material into the two primary feed bins 1 respectively.

[0082] Step 3. The magnesium-containing material and the flux are ground by the material grinder 2 respectively, and then fall into the weight metering device 3 for weighing, and the volume flow rate of the material is controlled at 0.5 L / min to 1.5 L / min.

[0083] Step 4. Open the outlet of the first-level air lock 4 to allow the flux and magnesium-containing material to enter the second-level feed bin 6.

[0084] Step 5. The flux and the magnesium-containing raw material are stirred in the secondary feeding bin 6 by the primary stirring system 7, the material is further finely ground, and enters the secondary stirring system 10 through the secondary air lock 9.

[0085] Step 6. The finely ground material is further mixed by the secondary mixing system 10. The material volume flow rate is controlled between 0.5 L / min and 1.5 L / min, and the particle size is fine, ranging from 30 μm to 100 μm. The mixed material enters the throat ejector 12 at a controlled flow rate between 0.5 L / min and 1.5 L / min. Simultaneously, the inert gas inlet valve II 11 is opened, allowing inert gas to enter the throat ejector 12, which is made of steel-connected carbide. The material from the throat of the venturi tube 13 to its connection with the molten pool is the same as that of the throat ejector 12.

[0086] Step 7. Control the inert gas flow rate at the inert gas inlet II 11 end of the venturi tube 13 to 0.5m 3 / h~2.5m 3 / h, during this process, the jet velocity of the material during the inert gas blowing is guaranteed to be 0.5m / s~1.5m / s.

[0087] Step 8. The material undergoes a reduction reaction with the molten reducing agent in the molten bath. The metallic magnesium vapor generated during the reduction process is collected through a condenser and subsequently further refined and purified. The tailings generated during the reduction smelting process are further harmlessly treated.

[0088] Example 4:

[0089] This embodiment provides a raw material feeding method based on molten pool magnesium smelting, which is implemented using the device in Example 1 and includes the following steps:

[0090] Step 1. Coarsely grind one or more fluxes, such as calcium fluoride, sodium fluoride, potassium fluoride, and magnesium fluoride, into fine particles with a diameter of 40 to 100 μm. Coarsely grind magnesium-containing raw materials, such as dolomite, magnesite, and brucite, into fine particles with a diameter of 40 to 100 μm. Coarsely grind reducing agents, such as #75 ferrosilicon, Si, Al, and aluminum alloys, into fine particles with a diameter of 40 to 100 μm.

[0091] Step 2. Add the coarsely ground reducing agent into the molten pool, start induction heating, and heat the molten pool; add the coarsely ground magnesium-containing raw material flux raw material into the two primary feed bins 1 respectively.

[0092] Step 3. The magnesium-containing material and the flux are ground by the material grinder 2 respectively, and then fall into the weight metering device 3 for weighing, and the volume flow rate of the material is controlled at 0.6 L / min to 1.4 L / min.

[0093] Step 4. Open the outlet of the first-level air lock 4 to allow the flux and magnesium-containing material to enter the second-level feed bin 6.

[0094] Step 5. The flux and the magnesium-containing raw material are stirred in the secondary feeding bin 6 by the primary stirring system 7, the material is further finely ground, and enters the secondary stirring system 10 through the secondary air lock 9.

[0095] Step 6. The finely ground material is further mixed by the secondary stirring system 10. The material volume flow rate is controlled between 0.6L / min and 1.4L / min, and the particle size is fine, ranging from 40μm to 100μm. The mixed material enters the throat ejector 12. The material volume flow rate is controlled between 0.6L / min and 1.4L / min. Simultaneously, the inert gas inlet valve II 11 is opened, allowing inert gas to enter the titanium carbide cermet throat ejector 12. The material from the throat of the venturi tube 13 to its connection with the molten pool is the same as that of the throat ejector 12.

[0096] Step 7. Control the inert gas flow rate at the inert gas inlet II 11 end of the venturi tube 13 to 0.8m 3 / h~2.4m 3 / h, during which the jet velocity of the material during the inert gas blowing is ensured to be 0.6m / s~1.4m / s.

[0097] Step 8. The material undergoes a reduction reaction with the molten reducing agent in the molten bath. The metallic magnesium vapor generated during the reduction process is collected through a condenser and subsequently further refined and purified. The tailings generated during the reduction smelting process are further harmlessly treated.

[0098] Example 5:

[0099] This embodiment provides a raw material feeding method based on molten pool magnesium smelting, which is implemented using the device in Example 1 and includes the following steps:

[0100] Step 1. Coarsely grind one or more fluxes (calcium fluoride, sodium fluoride, potassium fluoride, and magnesium fluoride) into fine particles with a diameter of 50 to 80 μm. Coarsely grind magnesium-containing raw materials (such as dolomite, magnesite, and brucite) into fine particles with a diameter of 50 to 80 μm. Coarsely grind reducing agents (such as #75 ferrosilicon, Si, Al, and aluminum alloy) into fine particles with a diameter of 50 to 80 μm.

[0101] Step 2. Add the coarsely ground reducing agent into the molten pool, start induction heating, and heat the molten pool; add the coarsely ground magnesium-containing raw material flux raw material into the two primary feed bins 1 respectively.

[0102] Step 3. The magnesium-containing material and the flux are ground by the material grinder 2 respectively, and then fall into the weight metering device 3 for weighing, and the volume flow rate of the material is controlled at 0.8 L / min to 1.2 L / min.

[0103] Step 4. Open the outlet of the first-level air lock 4 to allow the flux and magnesium-containing material to enter the second-level feed bin 6.

[0104] Step 5. The flux and the magnesium-containing raw material are stirred and further finely ground in the secondary feeding bin 6 through the primary stirring system 7 and then enter the secondary stirring system 10 through the secondary air lock 9.

[0105] Step 6. The finely ground material is further mixed by the secondary mixing system 10. The material volume flow rate is controlled between 0.8 L / min and 1.2 L / min, and the particle size is fine, ranging from 50 μm to 80 μm. The mixed material enters the throat ejector 12. The material volume flow rate is controlled between 0.8 L / min and 1.2 L / min. Simultaneously, the inert gas inlet valve II 11 is opened, allowing inert gas to enter the nickel-chromium alloy throat ejector 12. The material from the throat of the venturi tube 13 to its connection with the molten pool is the same as that of the throat ejector 12.

[0106] Step 7. Control the inert gas flow rate at the inert gas inlet II 11 end of the venturi tube 13 to 0.8m 3 / h~1.2m 3 / h, during which the jet velocity of the material during the inert gas blowing is ensured to be 0.8m / s~1.2m / s.

[0107] Step 8. The material undergoes a reduction reaction with the molten reducing agent in the molten bath. The metallic magnesium vapor generated during the reduction process is collected through a condenser and subsequently further refined and purified. The tailings generated during the reduction smelting process are further harmlessly treated.

[0108] The above technical solution illustrates the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes and modifications made to the above technical solution based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A raw material feeding device based on molten pool magnesium smelting, characterized in that: It includes a primary feeding system, a secondary feeding system, an air shutoff system and a Venturi jet system; wherein the Venturi jet system includes a Venturi tube and a throat ejector arranged at its throat; the air shutoff system includes a primary air shutoff and a secondary air shutoff; The primary feeding system is located above the secondary feeding system and is connected to the secondary feeding system through a pipeline provided with a primary air lock; the secondary feeding system is connected to the throat of the venturi tube through a pipeline, and the secondary air lock is provided on the pipeline between the secondary feeding system and the throat of the venturi tube in the venturi jet system.

2. A raw material feeding device based on molten pool magnesium smelting according to claim 1, characterized in that: The first-level feeding system includes two first-level feeding bins with exactly the same structure; a material grinder is provided in the middle of the first-level feeding bin, and a weight metering device is provided below the material grinder; after the raw materials are ground by the material grinder, they fall into the weight metering device for weighing, control the flow of the materials, and enter the first-level air lock.

3. A raw material feeding device based on molten pool magnesium smelting according to claim 1, characterized in that: The secondary feeding system includes a secondary feeding bin and a primary stirring system arranged in the secondary feeding bin; the secondary feeding bin takes the transmission shaft as the central axis, and a fan-blade stirring paddle is provided on the transmission shaft; the transmission shaft and the fan-blade stirring paddle constitute a primary stirring system; an inert gas inlet I is provided at one end of the secondary feeding bin; an oxygen monitor is also provided at the outlet of the secondary feeding bin; the primary stirring system further grinds the material while stirring the material; the outlet of the secondary feeding bin is connected to a secondary air lock, a secondary stirring system, and a venturi tube in sequence through a pipeline.

4. A raw material feeding device based on molten pool magnesium smelting according to claim 3, characterized in that: The first-stage air lock and the second-stage air lock are impeller-type structures.

5. The raw material feeding device based on molten pool magnesium smelting according to claim 1, characterized in that: The two ends of the venturi tube are respectively provided with an inert gas inlet II and a material and inert gas outlet, and the material and inert gas outlet are sealedly connected to the molten pool; after the material enters the venturi tube, the inert gas entering the venturi tube through the inert gas inlet II is blown into the molten pool from the throat ejector inlet.

6. A raw material feeding device based on molten pool magnesium smelting according to claim 5, characterized in that: The throat ejector is a patch arranged at the throat of the venturi tube, and the thickness of the patch is 0.5mm to 3mm.

7. A raw material feeding device based on molten pool magnesium smelting according to claim 6, characterized in that: The throat ejector and the part from the throat of the venturi tube to the connection with the molten pool are made of the same material, which is hard alloy, including one of cast iron, steel-connected hard alloy, metal ceramic, nickel-based alloy, and tungsten-molybdenum alloy; The metal ceramic is tungsten carbide or titanium carbide.

8. The raw material feeding device based on molten pool magnesium smelting according to claim 6, characterized in that: The inner surfaces of the throat ejector and the venturi tube from the throat to the connection with the molten pool are electroplated or sprayed with a wear-resistant coating.

9. The raw material feeding device based on molten pool magnesium smelting according to claim 5, characterized in that: The inert gas inlet II is connected to an inert gas recovery and circulation device and is equipped with a gas compression and reflux supply system. The inert gas is recycled through the inert gas recovery and circulation device.

10. A raw material feeding method based on molten pool magnesium smelting, implemented by the device according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step 1. Coarsely grinding the magnesium-containing raw material, reducing agent and flux respectively; Step 2. Add the coarsely ground reducing agent to the molten pool and start induction heating to heat the molten pool; add the coarsely ground magnesium-containing raw material and flux raw material to two primary feed bins respectively; Step 3. The magnesium-containing raw material and flux are ground in a material grinder and then dropped into a weight metering device for weighing to control the material volume flow rate; Step 4. Open the first-stage air lock outlet, and the material enters the second-stage feed bin through the first-stage air lock; Step 5. The magnesium-containing raw material and flux are stirred in the secondary feeding bin by the primary stirring system, further ground and mixed, and then enter the secondary stirring system through the secondary air lock; Step 6. The mixed materials after further grinding are further mixed by stirring in a secondary stirring system and fall into the throat of the venturi tube; Step 7. After the material enters the venturi tube, the inert gas entering the venturi tube through the inert gas inlet II is sprayed from the throat ejector inlet into the molten pool; Step 8. The material undergoes a reduction reaction with the molten reducing agent in the molten bath. The metallic magnesium vapor generated during the reduction process is collected through a condenser and further refined and purified. The tailings produced during the reduction smelting process are further treated harmlessly.

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