A two-stage continuous smelting and casting forming method and device for molybdenum-iron alloy

Abstract

This invention belongs to the field of ferromolybdenum alloy smelting technology, specifically relating to a two-stage continuous smelting and casting method and apparatus for ferromolybdenum alloys. This invention couples the aluminothermic rapid reduction reaction with medium-frequency induction refining. The ferromolybdenum alloy liquid is conveyed by gravity through slag blocking and sealing into the medium-frequency refining tundish, completing heat preservation, homogenization, secondary slag removal, and flow stabilization. Subsequently, it is directly and continuously cast into 30-50mm thick ingot-shaped ingots, achieving near-net-shape forming, eliminating crushing and screening. This invention solves the problems of component segregation, high oxygen content, intermittent production, large crushing losses, and severe dust pollution associated with the traditional aluminothermic process for ferromolybdenum. It features a short process, high efficiency, superior quality, environmental friendliness, and high degree of automation. The prepared ferromolybdenum ingots have uniform size, stable composition, and an oxygen content ≤80ppm, and can be directly used in special steel smelting, suitable for the continuous industrial production of high-end ferromolybdenum alloys.

Description

Technical Field

[0001] This invention belongs to the field of ferromolybdenum alloy smelting technology, specifically relating to a two-stage continuous smelting and casting method and apparatus for ferromolybdenum alloy. Background Technology

[0002] Ferromolybdenum alloys are core molybdenum additives used in steel smelting and special alloy preparation. They are widely used in high-end equipment manufacturing, nuclear power engineering, aerospace, and military industries, and are indispensable key raw materials in the production of special steels, high-temperature alloys, and corrosion-resistant alloys. With the rapid development of high-end manufacturing, downstream industries are placing increasingly stringent requirements on the compositional uniformity, cleanliness, and batch stability of ferromolybdenum alloys. In particular, high-end special steels used in nuclear power and aerospace have set extremely high entry barriers for ferromolybdenum alloys in terms of oxygen content, compositional deviation, and inclusion content.

[0003] The aluminothermic process is currently the mainstream technology for ferromolybdenum alloy production in China due to its fast reaction speed, short process flow, low energy consumption, and simple operation. However, the traditional intermittent aluminothermic ferromolybdenum production process, limited by its own process principles and equipment, has many inherent defects that are difficult to overcome, making it difficult to meet the needs of the downstream high-end market, as follows:

[0004] 1. Severe segregation of melt composition and poor batch stability. The aluminothermic self-propagating reaction is characterized by instantaneous exothermic reaction and drastic temperature fluctuations. The peak reaction temperature can reach 1800-2500℃, and the entire reaction process takes only tens to hundreds of seconds. The melt cannot be fully mixed, and after the reaction, there is only a single settling and slag-metal separation process. The compositional uniformity is difficult to control, and the molybdenum content of the finished product fluctuates greatly, which cannot meet the narrow compositional range control requirements of high-end steel grades.

[0005] 2. Continuous production is impossible, the process is lengthy, and production efficiency is low. In traditional processes, the melt cools down very quickly after the aluminothermic reaction, making it impossible to achieve stable heat preservation and continuous conveying. Only intermittent large ingot casting can be used. After the large ingot solidifies, it must go through multiple post-processing steps such as crushing, screening, and magnetic separation to obtain the finished product. The production cycle is long, the reliance on manual labor is high, the level of automation is low, and the capacity increase is limited.

[0006] 3. High metal loss rate and significant environmental pressure. The crushing and screening processes generate a large amount of ultrafine powder that cannot be directly utilized, resulting in a high overall metal loss rate. At the same time, the crushing process is accompanied by severe dust pollution, creating a harsh working environment that does not meet the national policy requirements for green and clean production.

[0007] 4. Insufficient product cleanliness and high oxygen content. In traditional processes, the conveying and casting of high-temperature melts are all open operations, with the melt in direct contact with air, making it very easy for oxidation and gas absorption to occur, resulting in a high oxygen content in the finished product; moreover, only a single slag-metal separation is performed, and the removal of inclusions is insufficient, making it difficult for the product cleanliness to meet the requirements of high-end applications.

[0008] 5. Existing technological improvements have limitations. Currently, improvements to the aluminothermic ferromolybdenum production process in the industry are mostly focused on single aspects such as optimizing the structure of the aluminothermic reactor and adjusting the raw material ratio. They have failed to achieve full-process coupling of aluminothermic reduction reaction, melt holding and refining, and continuous near-net-shape forming. This cannot fundamentally solve the inherent pain points of intermittent production, nor can it achieve the goal of directly producing finished ingots without crushing.

[0009] Based on this, the technical solution of the present invention is proposed. Summary of the Invention

[0010] To address the problems existing in the prior art, this invention provides a continuous production scheme for ferromolybdenum using the aluminothermic process, which features a short process, high efficiency, superior quality, and environmental friendliness. By organically combining rapid aluminothermic reaction, medium-frequency insulated refining, and continuous near-final casting, it achieves the effect of direct molding of ferromolybdenum alloy without breakage, fundamentally solving the technical problems of traditional processes.

[0011] The present invention provides a two-stage continuous smelting and casting method for ferromolybdenum alloy, the method comprising the following steps: (1) Molybdenum oxide, iron oxide, aluminum granules and flux are mixed and added to a closed aluminothermic reactor, and then ignited to react. After the reaction is completed, the mixture is allowed to stand to achieve preliminary slag-metal separation and obtain ferromolybdenum alloy liquid. (2) A sealed, heat-insulated, and self-flowing system is used to transport the molten molybdenum-iron alloy to the intermediate ladle of medium-frequency induction heat-insulated refining under an inert atmosphere; (3) The ferromolybdenum alloy liquid is stirred and homogenized under heat preservation conditions and subjected to secondary slag-gold separation to obtain a refined alloy liquid; (4) The refined alloy liquid is cast through a continuous casting ingot forming device to obtain iron-molybdenum ingots; (5) The iron-molybdenum ingots can be transported and collected by a cooling conveying system.

[0012] Preferably, in step (1), molybdenum oxide, iron oxide, aluminum particles and flux are mixed and added to a closed aluminothermic reactor, then ignited and an aluminothermic self-propagating reaction occurs at 1800-2200℃. After the reaction is completed, the mixture is allowed to stand to achieve preliminary slag-metal separation and obtain a molten molybdenum-iron alloy.

[0013] Preferably, in step (1), the mass ratio of molybdenum oxide, iron oxide, aluminum particles and flux is 60-70:15-25:10-15:2-4; And / or, the molybdenum oxide is MoO3, and the flux is fluorite.

[0014] Preferably, in step (2), a sealed and heat-insulated self-flowing system is used to transport the molten molybdenum-iron alloy to the intermediate ladle of medium-frequency induction heat-insulated refining under an argon atmosphere with a pressure of 200-500Pa.

[0015] Preferably, in step (3), the ferromolybdenum alloy liquid is electromagnetically stirred and homogenized for 2-5 minutes under a heat preservation condition of 1650-1750℃ and a secondary slag-gold separation is performed to obtain a refined alloy liquid.

[0016] Preferably, in step (4), the refined alloy liquid is cast through a continuous casting ingot forming device to obtain an iron-molybdenum ingot with a thickness of 30-50mm.

[0017] Preferably, in step (5), the iron-molybdenum ingot is transported and collected through a cooling conveying system to obtain an iron-molybdenum alloy product with an oxygen content ≤80ppm.

[0018] Based on the same technical concept, the present invention further provides an apparatus for realizing the two-stage continuous smelting and casting method of the ferromolybdenum alloy, the apparatus comprising, in sequence, a closed aluminothermic reactor, a sealed heat-insulating self-flowing system, a medium-frequency induction heat-insulating refining tundish, a continuous ingot forming device, and a cooling conveying system; wherein: The sealed aluminothermic reactor is used for the aluminothermic self-propagating reaction of raw materials; more specifically, the sealed aluminothermic reactor is equipped with a sealed furnace cover, an iron tap, a slag baffle, and a slag discharge port; the sealed furnace cover is used to seal the reactor to provide a closed environment, the iron tap is used to discharge molten molybdenum-iron alloy, the slag baffle is used to block the initially separated slag and gold, and the slag discharge port is used to discharge the initially separated slag and gold.

[0019] The sealed and insulated self-flowing system is used to transport molten molybdenum-iron alloy under an inert atmosphere; the sealed and insulated self-flowing system is an inclined insulated flow channel and is equipped with an inert gas (argon) protection device.

[0020] The intermediate frequency induction refining tundish is used to stir and homogenize the ferromolybdenum alloy liquid and to separate slag from gold. The intermediate frequency induction refining tundish includes an induction heating coil, an electromagnetic stirring mechanism, a temperature measuring component, and a liquid level monitoring device. The induction heating coil is used for heating and heat preservation, the electromagnetic stirring mechanism is used for stirring and homogenizing the ferromolybdenum alloy liquid, the temperature measuring component is used for measuring the temperature, and the liquid level monitoring device is used for measuring the liquid level of the ferromolybdenum alloy liquid. Simultaneously, the intermediate frequency induction refining tundish also includes a fully sealed water-cooled structure and a protective gas inlet at the top to maintain a slightly positive pressure atmosphere inside the furnace.

[0021] The continuous casting ingot forming device is used for continuous casting of refined alloys; the continuous casting ingot forming device is a rotary or chain-type ingot-shaped continuous casting ingot forming device, the mold is an ingot-shaped cavity with a cavity thickness of 30-50mm. The ingot-shaped continuous casting ingot forming device is equipped with an automatic pouring mechanism, a gradient cooling system and an automatic demolding mechanism, which can realize continuous casting and automatic demolding.

[0022] The cooling and conveying system is used to transport and collect iron-molybdenum ingots; the cooling and conveying system integrates closed-loop air cooling, conveying, collection and testing to ensure the quality of the finished product.

[0023] It should be noted that the device has a two-section layout. The closed aluminothermic reactor is the rapid reaction section, and the medium-frequency induction heating and refining intermediate ladle to continuous casting ingot forming device is the heating and refining and continuous forming section. The entire process of the device has no open casting and no crushing process, achieving clean production with no dust, low oxidation, and high yield.

[0024] The beneficial effects of this invention are as follows: This invention addresses the inherent shortcomings of the traditional aluminothermic process for producing ferromolybdenum by organically coupling a two-stage process of rapid aluminothermic reduction and medium-frequency induction refining, coupled with a fully enclosed continuous production line. This achieves efficient, high-quality, and environmentally friendly production of ferromolybdenum alloys, with the following specific benefits: 1. This invention adopts a two-stage process layout. The closed aluminothermic reactor is responsible for efficiently completing the aluminothermic self-propagating reduction reaction and the initial slag-metal separation. The medium-frequency induction holding and refining tundish can realize constant temperature control of the melt, electromagnetic stirring homogenization and deep slag-metal separation, effectively eliminating the composition segregation problem caused by the instantaneous aluminothermic reaction. The uniform deviation of molybdenum content in the finished product is ≤0.5%, the batch stability is greatly improved, and it can fully meet the control requirements of narrow composition range of high-end steel grades.

[0025] 2. This invention achieves a sealed connection between the aluminothermic reactor and the refining tundish through a sealed and heat-insulating self-flowing system. Combined with a continuous casting ingot forming device, it realizes a semi-continuous / continuous operation of the entire process of reduction, refining, casting, and cooling. There is no need to stop the furnace for cooling, and the production efficiency is increased by more than 50% compared with the traditional process. The entire process adopts automated control, which greatly reduces manual intervention and reduces labor costs by 70%.

[0026] 3. This invention directly casts 30-50mm thick ingot-shaped finished ingots using a continuous casting ingot forming device, completely eliminating post-processing steps such as crushing, screening, and magnetic separation in traditional processes. No ultrafine powder is generated, and the metal yield is increased by more than 5% compared to traditional processes. At the same time, the entire process adopts a closed design, with no dust overflow, which completely solves the dust pollution problem in the crushing process and achieves green and clean production.

[0027] 4. In this invention, the entire process of conveying, refining, and casting the high-temperature melt is carried out under a slightly positive pressure inert atmosphere of argon, which completely isolates the air and eliminates the oxidation and gas absorption of the high-temperature melt. Combined with two slag-metal separation processes and electromagnetic stirring homogenization, the inclusions in the melt can be deeply removed, and the final product oxygen content is ≤80ppm. The product cleanliness is significantly improved and can meet the stringent requirements of high-end fields such as nuclear power and aerospace.

[0028] 5. The process and equipment layout of this invention can be directly upgraded and transformed on existing traditional aluminothermic ferromolybdenum production lines without rebuilding the core furnace body. The transformation cost is low, the commissioning cycle is short, the cost performance is extremely high, and it is easy to promote and apply on a large scale in the industry. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a process flow diagram of the present invention.

[0031] Figure 2 This is a schematic diagram of the apparatus for realizing the two-stage continuous smelting and casting method of the ferromolybdenum alloy according to the present invention.

[0032] The attached figures are labeled as follows: 1-Sealed aluminothermic reactor; 2-Sealed and heat-insulated self-flowing system; 3-Medium frequency induction heat-insulated refining tundish; 4-Continuous casting ingot forming device; 5-Cooling conveying system. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0034] Example 1 This embodiment provides a two-stage continuous smelting and casting method for ferromolybdenum alloy, the method comprising the following steps: (1) 65 kg of molybdenum trioxide (MoO3), 20 kg of iron oxide (Fe2O3), 12 kg of aluminum granules and 3 kg of fluorite flux were dried separately at a temperature of 150℃ and a holding time of 2 h, and the moisture content of the raw materials was controlled to be ≤0.1% by mass. After drying, all raw materials were added to a mixer and mixed evenly for 15 min to obtain mixed furnace charge. Among them, the particle size of molybdenum trioxide was controlled to be 80-200 mesh, the particle size of iron oxide was controlled to be 100-200 mesh, and the particle size of aluminum granules was controlled to be 0.1-1 mm.

[0035] (2) Clean the furnace cavity of the sealed aluminothermic reactor, remove the residual slag and impurities in the furnace, close the furnace cover and pre-evacuate to the absolute pressure in the furnace ≤100Pa, then introduce high-purity argon gas to the furnace to a slightly positive pressure, repeat the replacement twice, and control the initial oxygen volume fraction in the furnace ≤0.5%; add the mixed furnace charge obtained in step (1) into the reactor through the sealed feeding system, spread the furnace charge evenly and insert the ignition device, close the furnace cover to complete the sealing.

[0036] (3) Aluminothermic reduction reaction and preliminary slag-metal separation: The furnace charge is ignited by the ignition device to initiate the aluminothermic self-propagating reaction. The peak temperature of the reaction is controlled at 2050℃ and the total reaction time is 90s. After the reaction is completed, the furnace body is kept sealed and left to stand for 3 minutes to allow the melt to complete the preliminary slag-metal separation. After standing, the molten slag is discharged through the slag discharge port, while the molten molybdenum-iron alloy liquid is retained.

[0037] (4) Preheat the inclined insulated flow channel of the sealed and insulated self-flowing system in advance to 1200℃; open the iron outlet of the reactor, and after the residual slag is blocked by the baffle plate, the molten molybdenum-iron alloy enters the sealed and insulated self-flowing system. Under the protection of the inert atmosphere of high-purity argon gas with a slight positive pressure of 300Pa, it is transported by gravity to the intermediate ladle of medium frequency induction heat preservation refining; the air is isolated throughout the transportation process to prevent the melt from oxidizing and absorbing gas.

[0038] (5) The intermediate ladle for medium-frequency induction heat preservation refining is preheated to 1500℃ and replaced with argon atmosphere in advance. After the ferromolybdenum alloy liquid enters, the heat preservation temperature in the furnace is controlled to be constant at 1700℃. At the same time, the electromagnetic stirring mechanism is started to perform electromagnetic stirring and homogenization of the melt for 3 minutes to make the alloy composition fully homogenized and eliminate composition segregation. After stirring, it is left to stand for 2 minutes to complete the secondary slag-gold separation. The upper layer of refined slag is discharged through the slag discharge port to obtain the lower layer of refined alloy liquid. High-purity argon is continuously introduced during the process to maintain a slightly positive pressure atmosphere in the furnace.

[0039] (6) Preheat the ingot-shaped mold of the continuous casting ingot forming device in advance. The preheating temperature is 300℃ and the mold cavity thickness is 40mm. Control the liquid level of the intermediate ladle of medium frequency induction heat preservation to stabilize. The refined alloy liquid is continuously poured into the ingot-shaped mold at a stable flow rate through the constant flow casting mechanism. The melt solidifies through the gradient cooling system and the formed ferromolybdenum ingot is removed through the automatic demolding mechanism.

[0040] (7) After demolding, the ferromolybdenum castings enter a closed cooling and conveying system and are forced to cool by air cooling. The air cooling speed is controlled at 6 m / s and the cooling time is 15 min. After the casting temperature drops below 100℃, the conveying and collection are completed to obtain the ferromolybdenum alloy finished product. No crushing or screening is required throughout the process.

[0041] The finished product of this embodiment has the following specifications after testing: Mo mass fraction 62%, O mass fraction 65ppm, composition uniformity deviation ≤0.4%, the ingot is in the shape of a sycee, the size is uniform, the surface is smooth, and it can be directly put into the furnace for use without additional treatment.

[0042] Example 2 This embodiment provides a two-stage continuous smelting and casting method for ferromolybdenum alloy, which is basically the same as that in Embodiment 1, and includes the following briefly described steps: (1) Mix 65kg of MoO3, 20kg of Fe2O3, 12kg of aluminum granules and 3kg of fluorite flux evenly and add them to a closed aluminothermic reactor. Then ignite the reactor to initiate a reaction. The peak temperature is 2050℃ and the reaction time is 90s. Let it stand for 4min to complete the initial slag-gold separation and obtain a molten molybdenum-iron alloy. (2) Open the tap hole. After the molten ferromolybdenum alloy liquid is blocked by the slag baffle, the molten ferromolybdenum alloy liquid is transported to the intermediate frequency induction heat preservation refining tundish under argon atmosphere by a sealed heat preservation self-flowing system, and the slight positive pressure of argon is kept at 350Pa to prevent oxidation and gas absorption. (3) Set the heat preservation temperature of the intermediate ladle of medium frequency induction heat preservation refining to 1680℃, and perform electromagnetic stirring on the ferromolybdenum alloy liquid for 4 minutes to homogenize the composition and eliminate segregation; at the same time, realize secondary slag-gold separation, reduce oxygen content and inclusions, and obtain refined alloy liquid. (4) The refined alloy liquid is fed into the continuous casting ingot forming device at a stable flow rate and directly cast into a 35mm ingot-shaped ingot, and then automatically cast, solidified and demolded; (5) Finally, the finished product is collected directly through the cooling and conveying system without crushing or screening, and the finished ferromolybdenum casting is obtained.

[0043] The product specifications, as tested, are as follows: Mo content: 60%, O content: 62ppm, composition fluctuation: ≤0.4%, and the ingot appearance is ingot-shaped, uniform in size, and has a smooth surface. It can be used directly in the furnace without further treatment.

[0044] Example 3 This embodiment provides a two-stage continuous smelting and casting method for ferromolybdenum alloy, which is basically the same as that in Embodiment 1, and includes the following briefly described steps: (1) Mix 65kg of MoO3, 20kg of Fe2O3, 12kg of aluminum granules and 3kg of fluorite flux evenly and add them to a closed aluminothermic reactor. Then ignite the reactor to initiate a reaction. The peak temperature is 2050℃ and the reaction time is 90s. Let it stand for 5min to complete the initial slag-gold separation and obtain a molten molybdenum-iron alloy. (2) Open the tap hole. After the molten ferromolybdenum alloy liquid is blocked by the slag baffle, the molten ferromolybdenum alloy liquid is transported to the intermediate frequency induction heat preservation refining tundish under argon atmosphere by a sealed heat preservation self-flowing system, and the slight positive pressure of argon is kept at 400 Pa to prevent oxidation and gas absorption. (3) Set the heat preservation temperature of the intermediate ladle of medium frequency induction heat preservation refining to 1690℃, and electromagnetically stir the ferromolybdenum alloy liquid for 5 minutes to homogenize the composition and eliminate segregation; at the same time, realize secondary slag-gold separation, reduce oxygen content and inclusions, and obtain refined alloy liquid. (4) The refined alloy liquid is fed into the continuous casting ingot forming device at a stable flow rate and directly cast into a 45mm ingot-shaped ingot, and then automatically cast, solidified and demolded; (5) Finally, the finished product is collected directly through the cooling and conveying system without crushing or screening, and the finished ferromolybdenum casting is obtained.

[0045] The product specifications, as tested, are as follows: Mo content: 61%, O content: 63ppm, composition fluctuation: ≤0.4%, and the ingot appearance is ingot-shaped, uniform in size, and has a smooth surface. It can be used directly in the furnace without further treatment.

[0046] Example 4 refer to Figure 2 This embodiment provides an apparatus for implementing the two-stage continuous smelting and casting method of the ferromolybdenum alloy. The apparatus includes a sealed aluminothermic reactor 1, a sealed and heat-insulating self-flowing system 2, a medium-frequency induction heat-insulating refining tundish 3, a continuous ingot forming device 4, and a cooling and conveying system 5, connected in sequence. The sealed aluminothermic reactor 1 is used for the aluminothermic self-propagating reaction of raw materials; more specifically, the sealed aluminothermic reactor 1 is equipped with a sealed furnace cover, an iron tap, a slag baffle plate, and a slag discharge port; the sealed furnace cover is used to seal the reactor to provide a closed environment, the iron tap is used to discharge molten molybdenum-iron alloy, the slag baffle plate is used to block the initially separated slag and gold, and the slag discharge port is used to discharge the initially separated slag and gold.

[0047] The sealed and insulated self-flowing system 2 is used to transport molten molybdenum-iron alloy under an inert atmosphere; the sealed and insulated self-flowing system 2 is an inclined insulated flow channel and is equipped with an inert gas (argon) protection device.

[0048] The intermediate frequency induction refining tundish 3 is used to stir and homogenize the ferromolybdenum alloy liquid and to separate slag from gold. The intermediate frequency induction refining tundish 3 has an induction heating coil, an electromagnetic stirring mechanism, a temperature measuring component, and a liquid level monitoring device. The induction heating coil is used for heating and heat preservation, the electromagnetic stirring mechanism is used for stirring and homogenizing the ferromolybdenum alloy liquid, the temperature measuring component is used for measuring the temperature, and the liquid level monitoring device is used for measuring the liquid level of the ferromolybdenum alloy liquid. At the same time, the intermediate frequency induction refining tundish 3 also includes a fully sealed water-cooled structure and a protective gas inlet at the top to maintain a slightly positive pressure atmosphere inside the furnace.

[0049] The continuous casting ingot forming device 4 is used for continuous casting of refined alloys; the continuous casting ingot forming device 4 is a rotary or chain-type ingot-shaped continuous casting ingot forming device, the mold is an ingot-shaped cavity with a cavity thickness of 30-50mm. The ingot-shaped continuous casting ingot forming device is equipped with an automatic pouring mechanism, a gradient cooling system and an automatic demolding mechanism, which can realize continuous casting and automatic demolding.

[0050] The cooling conveying system 5 is used for transporting and collecting iron-molybdenum ingots; the cooling conveying system 5 integrates closed-loop air cooling, conveying, collection and testing to ensure the quality of the finished product.

[0051] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A two-stage continuous smelting and casting method for ferromolybdenum alloy, characterized in that, The method includes the following steps: (1) Molybdenum oxide, iron oxide, aluminum granules and flux are mixed and added to a closed aluminothermic reactor, and then ignited to react. After the reaction is completed, the mixture is allowed to stand to achieve preliminary slag-metal separation and obtain ferromolybdenum alloy liquid. (2) A sealed, heat-insulated, and self-flowing system is used to transport the molten molybdenum-iron alloy to the intermediate ladle of medium-frequency induction heat-insulated refining under an inert atmosphere; (3) The ferromolybdenum alloy liquid is stirred and homogenized under heat preservation conditions and subjected to secondary slag-gold separation to obtain a refined alloy liquid; (4) The refined alloy liquid is cast through a continuous casting ingot forming device to obtain iron-molybdenum ingots; (5) The iron-molybdenum ingots can be transported and collected by a cooling conveying system.

2. The two-stage continuous smelting and casting method for ferromolybdenum alloy according to claim 1, characterized in that, In step (1), molybdenum oxide, iron oxide, aluminum granules and flux are mixed and added to a closed aluminothermic reactor. Then, the reactor is ignited and an aluminothermic self-propagating reaction occurs at 1800-2200℃. After the reaction is completed, the reactor is allowed to stand to achieve preliminary slag-metal separation and obtain ferromolybdenum alloy liquid.

3. The two-stage continuous smelting and casting method for ferromolybdenum alloy according to claim 1, characterized in that, In step (1), the mass ratio of molybdenum oxide, iron oxide, aluminum granules and flux is 60-70:15-25:10-15:2-4; And / or, the molybdenum oxide is MoO3, and the flux is fluorite.

4. The two-stage continuous smelting and casting method for ferromolybdenum alloy according to claim 1, characterized in that, In step (2), a sealed and heat-insulated self-flowing system is used to transport the molten molybdenum-iron alloy to the intermediate ladle of medium-frequency induction heat-insulated refining under an argon atmosphere with a pressure of 200-500Pa.

5. The two-stage continuous smelting and casting method for ferromolybdenum alloy according to claim 1, characterized in that, In step (3), the ferromolybdenum alloy liquid is electromagnetically stirred and homogenized for 2-5 minutes under a heat preservation condition of 1650-1750℃ and a secondary slag-gold separation is performed to obtain a refined alloy liquid.

6. The two-stage continuous smelting and casting method for ferromolybdenum alloy according to claim 1, characterized in that, In step (4), the refined alloy liquid is cast through a continuous casting ingot forming device to obtain an iron-molybdenum ingot with a thickness of 30-50mm.

7. The two-stage continuous smelting and casting method for ferromolybdenum alloy according to claim 1, characterized in that, In step (5), the iron-molybdenum ingot is transported and collected through a cooling conveying system to obtain an iron-molybdenum alloy finished product with an oxygen content of ≤80ppm.

8. An apparatus for implementing the two-stage continuous smelting and casting method for ferromolybdenum alloy according to any one of claims 1-7, characterized in that, The apparatus comprises, in sequence, a sealed aluminothermic reactor, a sealed and insulated self-flowing system, a medium-frequency induction refining tundish, a continuous ingot forming device, and a cooling conveying system; wherein: The sealed aluminothermic reactor is used for the aluminothermic self-propagating reaction of the raw materials. The sealed, heat-insulated, self-flowing system is used to transport molten molybdenum-iron alloy under an inert atmosphere; The intermediate frequency induction heat preservation refining tundish is used to stir and homogenize the molten molybdenum-iron alloy and to separate the slag from the metal. The continuous casting ingot forming device is used for continuous casting of refined alloys; The cooling conveying system is used for transporting and collecting iron-molybdenum ingots.

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