Method and apparatus for siphoning slag from the atmosphere using a vacuum induction furnace

Abstract

This invention provides a method and apparatus for siphoning slag from a vacuum induction furnace to the atmosphere, belonging to the field of metallurgical technology. It utilizes a siphon slag removal device to continuously discharge high-viscosity molten slag generated during metal smelting in a vacuum induction furnace. The apparatus includes a slag collection and separation device and a slag discharge channel. The slag collection and separation device is located above the molten pool in the vacuum induction furnace. The slag discharge channel includes an inner channel vertically disposed inside the side wall of the heating crucible of the vacuum induction furnace, a transition channel communicating with the lower part of the inner channel, and an outer channel connected to the outer port of the transition channel. The outer channel is vertically disposed, with its lower part communicating with the outer port of the transition channel. The pressure at the upper slag inlet of the inner channel is greater than the pressure at the upper slag outlet of the outer channel. This invention solves the problems in the prior art where, during metal smelting in a vacuum induction furnace, poor slag fluidity and difficulty in separating slag and metal lead to difficulties in slag removal, slag-metal mixing, and continuous slag discharge under vacuum conditions.

Description

Technical Field

[0001] This invention relates to the field of metallurgical technology, and more specifically, to a method and apparatus for siphoning slag from a vacuum induction furnace into the atmosphere. Background Technology

[0002] Metal smelting, such as magnesium smelting, primarily utilizes electrolysis and the silicothermic process. Electrolysis, in particular, is burdensome due to its long raw material preparation process, the generation of large amounts of chlorine gas and waste residue, and the high investment required for treating byproducts and waste. Typical silicothermic processes include the Magnehem process and the Pidgeon process. The Magnehem process enables continuous reaction of raw materials under liquid slag, resulting in high reduction efficiency and short reduction time. However, the problem of high-temperature electrode vacuum sealing remains unresolved, leading to safety issues and a lack of cost advantage. The Pidgeon process, on the other hand, features simpler equipment, lower investment, and lower costs; therefore, crude magnesium produced using the Pidgeon process currently accounts for over 80% of total primary magnesium production. However, the Pidgeon process suffers from high energy consumption, low resource utilization efficiency, severe environmental pollution, inability to achieve mechanized and automated production, and high carbon emission intensity.

[0003] To address the aforementioned problems in magnesium smelting processes, developing a highly efficient, environmentally friendly, low-cost, and energy-saving primary magnesium smelting process and equipment is an urgent requirement for industrial upgrading, transformation, and structural adjustment, as well as a necessity for green development. Therefore, a vacuum liquid injection method for smelting magnesium (or other metals) has been developed based on the transplantation of steelmaking equipment such as RH, single-nozzle refining furnaces, and VD technology. This technology obtains the finished product by injecting reduced calcined white powder into excess reduced ferrosilicon liquid. The entire smelting process involves continuous replenishment of reduced ferrosilicon liquid through a feeding channel. If slag can be continuously discharged through a slag discharge channel, continuous production of magnesium (or other metals) can be achieved, representing a completely new process. This method offers favorable thermodynamic and kinetic conditions, a rapid reaction rate, higher single-unit capacity than the Magnehem process, a significantly lower reduction temperature than the Magnehem process, and lower cost than the Pidgeon process. However, currently, there is no suitable and effective slag removal method for continuous discharge of liquid slag and slag-gold separation under vacuum conditions. For example, the existing patent CN111270088B discloses a system and method for continuous magnesium smelting using induction heating and liquid stirring. Although it provides a solution for continuous magnesium smelting through induction heating and liquid stirring, it does not specifically provide the design of the slag removal system. Patent CN117588946A discloses a continuous steel tapping induction melting furnace, which provides a system design for continuous steel tapping in the induction furnace under atmospheric conditions. However, it does not consider the sealing of the continuous steel tapping process, and therefore is not suitable for continuous slag tapping under vacuum conditions.

[0004] In summary, there is currently a lack of an effective solution for continuous slag removal in the existing technology for vacuum liquid jet smelting of metals.

[0005] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0006] In view of the above problems, the purpose of this invention is to provide a method and apparatus for siphoning slag from a vacuum induction furnace to the atmosphere, so as to solve the problem that there is no effective solution for continuous slag discharge in the prior art that can be used in the vacuum liquid injection metal smelting method.

[0007] This invention provides a method for siphoning slag from a vacuum induction furnace to the atmosphere, which utilizes a siphoning slag removal device to continuously discharge high-viscosity molten slag generated during metal smelting within the vacuum induction furnace, comprising the following steps:

[0008] Step S1: Install the siphon slag removal device on the vacuum induction furnace; wherein,

[0009] The siphon slag removal device includes a slag collection and separation device and a slag discharge channel. The slag collection and separation device is located above the molten pool of the vacuum induction furnace. The slag collection and separation device includes a slag collection hopper, a molten metal separation port located at the bottom of the slag collection hopper, and a slag separation port located on the side wall of the slag collection hopper. The slag discharge channel includes an inner channel vertically disposed inside the side wall of the heating crucible of the vacuum induction furnace, a transition channel communicating with the lower part of the inner channel, and an outer channel connected to the outer port of the transition channel. The lower end of the inner channel passes through the heating crucible. The transition channel is located within the vacuum space of the vacuum induction furnace; the inner port of the transition channel is connected to the lower end of the inner channel, and the outer port is horizontally inclined upward and passes through the vacuum space, located outside the vacuum induction furnace; the outer channel is vertically arranged, with its lower part connected to the outer port of the transition channel and its upper part connected to a discharge pipe with a downwardly inclined opening; the pressure at the upper slag inlet of the inner channel is greater than the pressure at the upper slag outlet of the outer channel; a first heating device is provided on the outer wall of the transition channel; a second heating device is provided on the outer wall of the outer channel.

[0010] Step S2: Collect the slag generated in the molten pool using the slag collection and separation device, and separate the collected slag from the molten metal using the molten metal separation port and the slag separation port, so that the separated slag enters the slag discharge channel from the slag separation port.

[0011] Step S3: The inner channel is heated by an induction coil arranged around the outer periphery of the heating crucible, the transition channel is heated by the first heating device, and the outer channel is heated by the second heating device to ensure that the temperature of the slag discharge channel is maintained at the preset slag discharge temperature so that high-viscosity molten slag is continuously discharged from the vacuum induction furnace.

[0012] Furthermore, in a preferred embodiment, during the installation of the siphon slag removal device on the vacuum induction furnace, the slag collection and separation device is positioned within the molten pool at a height of 50-100 mm above the molten slag surface.

[0013] Furthermore, in a preferred embodiment, during the process of installing the siphon slag removal device on the vacuum induction furnace, the inclination angle between the outer port of the transition channel and the horizontal plane is 10-20°.

[0014] Furthermore, a preferred embodiment is that the preset slag discharge temperature is 1450℃-1500℃.

[0015] This invention provides a siphon slag removal device for use in the method of siphoning slag from a vacuum induction furnace to the atmosphere as described above, comprising a slag collection and separation device and a slag removal channel; wherein,

[0016] The slag collection and separation device is installed above the molten pool of the vacuum induction furnace. The slag collection and separation device includes a slag collection hopper, a molten metal separation port installed at the bottom of the slag collection hopper, and a slag separation port installed on the side wall of the slag collection hopper.

[0017] The slag discharge channel includes an inner channel vertically disposed inside the side wall of the heating crucible of the vacuum induction furnace, a transition channel communicating with the lower part of the inner channel, and an outer channel connected to the outer port of the transition channel; wherein,

[0018] The lower end of the inner channel passes through the heating crucible and is located within the vacuum space of the vacuum induction furnace; the inner port of the transition channel is connected to the lower end of the inner channel, and the outer port is horizontally inclined upward and passes through the vacuum space, located outside the vacuum induction furnace; the outer channel is vertically arranged, with its lower part connected to the outer port of the transition channel, and its upper part connected to a discharge pipe with a downwardly inclined opening; the pressure at the upper slag inlet of the inner channel is greater than the pressure at the upper slag outlet of the outer channel;

[0019] A first heating device is provided on the outer wall of the transition channel; a second heating device is provided on the outer wall of the outer channel.

[0020] Furthermore, a preferred embodiment is that a first lower port is provided at the lower end of the inner channel, and a first sealing cover is provided at the first lower port; and / or, a second lower port is provided at the lower end of the outer channel, and a second sealing cover is provided at the second lower port; and / or, an upper port is provided at the upper end of the outer channel, and a third sealing cover is provided at the upper port; and / or, a fourth sealing cover is provided at the discharge port of the discharge pipe.

[0021] Furthermore, a preferred embodiment is that a first refractory material sealing structure is provided inside the first lower port; and / or, a second refractory material sealing structure is provided inside the second lower port; and / or, a third refractory material sealing structure is provided inside the upper port of the outer channel.

[0022] First refractory material sealing structure, second refractory material sealing structure, third refractory material sealing structure. Furthermore, a preferred embodiment is that the first heating device is a first silicon molybdenum heating rod; and / or, the second heating device is a second silicon molybdenum heating rod.

[0023] Furthermore, in a preferred embodiment, the sidewalls of both the transition channel and the outer channel sequentially comprise a graphite layer, a thermal insulation material layer, and a steel structure layer from the inside out.

[0024] Furthermore, a preferred embodiment is that a high-temperature resistant adhesive layer is provided between the insulation material layer and the steel structure layer in the transition channel and between the insulation material layer and the steel structure layer in the outer channel.

[0025] As can be seen from the above technical solution, the method and apparatus for siphoning slag from a vacuum induction furnace to the atmosphere provided by the present invention collects and separates the slag generated in the molten pool of the vacuum induction furnace through a slag collection and separation device installed above the molten pool. The separated slag enters the slag discharge channel from the slag separation port on the side wall of the slag collection hopper. The inner channel and the outer channel are connected by a transition channel. The pressure at the upper slag inlet of the inner channel is greater than the pressure at the upper slag outlet of the outer channel. Due to the pressure difference between the slag in the inner channel and the slag outlet of the outer channel, the slag entering the slag discharge channel is continuously siphoned using the siphon principle. The slag discharge process involves heating the inner channel using an induction coil surrounding the heating crucible, heating the transition channel using a first heating device, and heating the outer channel using a second heating device. This maintains the slag discharge channel at a preset temperature, ensuring the fluidity of the high-viscosity molten slag within the channel. This achieves slag-gold separation under vacuum conditions and continuous slag discharge. The process effectively solves the problems of poor slag fluidity, difficulty in separating slag and gold, and the inability to continuously discharge slag under vacuum conditions that arise in existing metal smelting processes using vacuum induction furnaces.

[0026] To achieve the foregoing and related objectives, one or more aspects of the invention include the features that will be described in detail below. The following description and accompanying drawings illustrate certain exemplary aspects of the invention. However, these aspects indicate only a few of the various ways in which the principles of the invention can be used. Furthermore, the invention is intended to encompass all such aspects and their equivalents. Attached Figure Description

[0027] Other objects and results of the invention will become more apparent and readily understood with reference to the following description taken in conjunction with the accompanying drawings, and with a more complete understanding of the invention.

[0028] Figure 1 This is a schematic diagram of the siphon slag removal device according to an embodiment of the present invention;

[0029] Figure 2 This is a partial structural diagram of the inner channel according to an embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of the slag collection and separation device according to an embodiment of the present invention;

[0031] Figure 4 This is a flowchart of a method for siphoning slag from the atmosphere using a vacuum induction furnace according to an embodiment of the present invention.

[0032] In the attached drawings, 1-slag collection and separation device, 11-slag collection hopper, 12-molten metal separation port, 13-slag separation port, 21-inner channel, 22-transition channel, 23-outer channel, 24-discharge pipe, 25-first heating device, 26-second heating device, 27-first insulation material layer, 28-second insulation material layer, 31-vacuum system, 32-vacuum space, 33-vacuum shell, 34-induction coil, 35-heating crucible, 36-molten pool, 361-slag, 362-molten metal, 37-feed channel, 41-first sealing cover, 42-second sealing cover, 43-third sealing cover, 44-fourth sealing cover, 51-first refractory material sealing structure, 52-second refractory material sealing structure, 53-third refractory material sealing structure, 61-slag pot, 62-slag pot car.

[0033] In all the accompanying drawings, the same reference numerals indicate similar or corresponding features or functions. Detailed Implementation

[0034] In the following description, numerous specific details are set forth for illustrative purposes and to provide a thorough understanding of one or more embodiments. However, it will be apparent that these embodiments may also be implemented without these specific details.

[0035] To address the lack of an effective solution for continuous slag removal in the aforementioned prior art for vacuum liquid injection metal smelting, a method and apparatus for siphoning slag from a vacuum induction furnace to the atmosphere is proposed.

[0036] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0037] To illustrate the method and apparatus for siphoning slag from an air induction furnace to the atmosphere provided by the present invention. Figure 1 The structure of the siphon slag removal device according to an embodiment of the present invention is shown; Figure 2 A partial structure of the inner channel according to an embodiment of the present invention is shown; Figure 3 The structure of a slag collection and separation device according to an embodiment of the present invention is shown; Figure 4 A process flow diagram of a method for siphoning slag from the atmosphere into a vacuum induction furnace according to an embodiment of the present invention is shown.

[0038] like Figures 1 to 4 As shown in the figure, the method for siphoning slag from a vacuum induction furnace to the atmosphere provided by the present invention utilizes a siphon slag removal device to continuously discharge high-viscosity molten slag generated during metal smelting in the vacuum induction furnace to the outside, and includes the following steps:

[0039] Step S1: Install a siphon slag removal device on the vacuum induction furnace; wherein,

[0040] The siphon slag removal device includes a slag collection and separation device 1 and a slag removal channel. The slag collection and separation device 1 is located above the molten pool 36 of the vacuum induction furnace. The slag collection and separation device 1 includes a slag collection hopper 11, a molten metal separation port 12 located at the bottom of the slag collection hopper 11, and a slag separation port 13 located on the side wall of the slag collection hopper 11. The slag removal channel includes an inner channel 21 vertically located inside the side wall of the heating crucible 35 of the vacuum induction furnace, a transition channel 22 communicating with the lower part of the inner channel 21, and an outer channel 23 communicating with the outer port of the transition channel 22. The lower end of the inner channel 21 passes through the heating crucible. 35, set inside the vacuum space 32 of the vacuum induction furnace; the inner port of the transition channel 22 is connected to the lower end of the inner channel 21, and the outer port is set horizontally upward and passes through the vacuum space 32, set outside the vacuum induction furnace; the outer channel 23 is set vertically, the lower part is connected to the outer port of the transition channel 22, and the upper part is connected to the discharge pipe 24 with an opening that slopes downward; the pressure at the upper slag inlet of the inner channel 21 is greater than the pressure at the upper slag outlet of the outer channel 23; a first heating device 25 is set on the outer wall of the transition channel 22; a second heating device 26 is set on the outer wall of the outer channel 23;

[0041] Step S2: Collect the slag generated in the molten pool 36 through the slag collection and separation device 1, and separate the collected slag from the molten metal using the molten metal separation port 12 and the slag separation port 13, so that the separated slag enters the slag discharge channel from the slag separation port 13.

[0042] Step S3: The inner channel 21 is heated by the induction coil 34 surrounding the heating crucible 35, the transition channel 22 is heated by the first heating device 25, and the outer channel 23 is heated by the second heating device 26, so as to ensure that the temperature of the slag discharge channel is maintained at the preset slag discharge temperature, so that the high-viscosity molten slag is continuously discharged from the vacuum induction furnace.

[0043] It should be noted that the vacuum induction furnace in this invention is a mature piece of equipment in the prior art. It includes a vacuum space 32 enclosed by a vacuum shell 33. A vacuum connection hole is provided on the vacuum shell 33 for connection to a vacuum system 31, thereby forming the vacuum space 32 within the vacuum shell 33. A heating crucible 35 is disposed within the vacuum space 32. An induction coil 34 surrounds the heating crucible 35. A vertical feed channel 37 is provided on the inner wall of the heating crucible 35 for adding metal raw materials from the outside into the interior of the heating crucible 35. The induction coil 34 heats and smelts the heating crucible 35, causing the metal raw materials inside the heating crucible 35 to melt and form a molten pool 36. The top of the molten pool 36 is slag 361, and the lower part of the slag 361 is molten metal 362. In this invention, the smelting slag refers to slag containing molten metal.

[0044] Among them, the heating crucible 35 is preferably, but not limited to, a graphite crucible, which has a good heating effect.

[0045] Both the feed channel 37 and the inner channel 21 are vertically arranged inside the side wall of the heating crucible 35. The outer channel 23 is vertically arranged outside the vacuum induction furnace.

[0046] The slag discharge channel in this invention utilizes the siphon principle to achieve continuous slag discharge. By controlling the continuous feeding speed, the molten slag is separated and then continuously discharged from the furnace by utilizing the pressure difference between the molten slag height in the inner channel 21 and the outlet of the outer channel 23. The specific settings of the molten slag height in the inner channel 21, the height of the slag outlet in the outer channel 23 (i.e., the outlet connecting the outer channel 23 and the discharge pipe 24), and the channel diameter can be calculated based on Bernoulli's equation, which is:

[0047]

[0048] Q≤πr 2 ·V1;

[0049] Where Z1 is the height of the slag outlet of the outer channel 23, V1 is the slag discharge velocity of the slag outlet of the outer channel 23, Z0 is the height of the inner channel 21 (the height of the molten slag inside the inner channel 21), V0 is the slag inlet velocity of the inner channel 21, the units of Z1 and Z0 are m, the units of V1 and V0 are m / s, P0 and P1 are the internal and external pressures of the vacuum induction furnace, respectively, the unit of which is Pa, and ρ is the density of the molten slag, the unit of which is kg / m³. 3 g is the acceleration due to gravity, with units of m / s². 2 h w Q represents the total pressure loss in the slag discharge channel, in Pa; Q represents the slag discharge rate per unit time, in m³. 3 / s; r is the radius of the inner channel 21 and the outer channel 23, both in meters. The radii of the inner channel 21 and the outer channel 23 are the same.

[0050] The slag collected and separated in the molten pool 36 of the vacuum induction furnace is collected and separated by the slag collection and separation device 1 located on the upper part of the molten pool 36. The separated slag enters the slag discharge channel from the slag separation port 13 on the side wall of the slag collection hopper 11. The inner channel 21 and the outer channel 23 are connected by the transition channel 22. Due to the pressure difference between the slag in the inner channel 21 and the slag discharge port of the outer channel 23, the slag entering the slag discharge channel is continuously discharged by using the siphon principle. The inner channel 21 is heated by the induction coil surrounding the heating crucible 35. The first heating device 25 heats the transition channel 22, and the second heating device 26 heats the outer channel 23 to keep the temperature of the slag discharge channel at the preset slag discharge temperature, ensuring the fluidity of the high-viscosity molten slag in the slag discharge channel, thereby realizing slag-gold separation and continuous discharge of molten slag under vacuum conditions; effectively solving the problems of poor slag fluidity, difficulty in separating slag and gold, and difficulty in continuous discharge of molten slag under vacuum conditions in the metal smelting process using a vacuum induction furnace in the prior art.

[0051] As a preferred embodiment of the present invention, during the installation of the siphon slag removal device on the vacuum induction furnace, the slag collection and separation device 1 is set in the molten pool 36 at a position 50-100 mm above the molten slag surface.

[0052] Specifically, the slag collection and separation device 1 collects slag by utilizing the slag surge and splash during the slag collection process. The slag collected into the slag collection hopper 11 still contains molten metal (metal melt). By using the molten metal separation port 12 and the slag separation port 13, the collected slag is separated from the molten metal, allowing the molten metal in the slag collection hopper 11 to return to the molten pool 36 through the molten metal separation port 12 at its bottom, while the slag enters the inner channel 21 through the slag separation port 13 on its side wall.

[0053] It should be noted that: the preferred embodiment of the present invention is to set the slag collection and separation device 1 in the molten pool 36 at a position 50-100mm above the molten slag surface. In actual application, the height of the slag collection and separation device 1 can be determined according to the actual surging or splashing height of the molten slag. The present invention does not make any special limitation on this.

[0054] As a preferred embodiment of the present invention, during the installation of the siphon slag removal device on the vacuum induction furnace, the inclination angle between the outer port of the transition channel 22 and the horizontal plane is 10-20°.

[0055] By setting the inclination angle between the outer port of the transition channel 22 and the horizontal plane to 10-20°, excessive liquid slag can be avoided from remaining in the pipeline when the furnace is shut down.

[0056] As a preferred embodiment of the present invention, the preset slag discharge temperature is 1450℃-1500℃.

[0057] It should be noted that the preset slag discharge temperature is preferably, but not limited to, 1450℃-1500℃. It can be limited according to the actual temperature at which the molten metal slag maintains fluidity. For most molten metal slags, 1450℃-1500℃ can ensure the fluidity of the slag.

[0058] like Figures 1 to 3 As shown in the diagram, the siphon slag removal device provided by the present invention is used in the method for siphoning slag from a vacuum induction furnace to the atmosphere, and includes a slag collection and separation device 1 and a slag removal channel; wherein,

[0059] The slag collection and separation device 1 is installed on the upper part of the molten pool 36 of the vacuum induction furnace. The slag collection and separation device 1 includes a slag collection hopper 11, a molten metal separation port 12 installed at the bottom of the slag collection hopper 11, and a slag separation port 13 installed on the side wall of the slag collection hopper 11.

[0060] The slag discharge channel includes an inner channel 21 vertically disposed inside the side wall of the heating crucible 35 in the vacuum induction furnace, a transition channel 22 communicating with the lower part of the inner channel 21, and an outer channel 23 communicating with the outer port of the transition channel 22; wherein,

[0061] The lower end of the inner channel 21 passes through the heating crucible 35 and is located inside the vacuum space 32 of the vacuum induction furnace; the inner port of the transition channel 22 is connected to the lower end of the inner channel 21, and the outer port is horizontally inclined upward and passes through the vacuum space 32, located outside the vacuum induction furnace; the outer channel 23 is vertically arranged, with its lower part connected to the outer port of the transition channel 22, and its upper part connected to a discharge pipe 24 with an opening that slopes downward; the pressure at the upper slag inlet of the inner channel 21 is greater than the pressure at the upper slag outlet of the outer channel 23.

[0062] A first heating device 25 is provided on the outer wall of the transition channel 22; a second heating device 26 is provided on the outer wall of the outer channel 23.

[0063] As a preferred embodiment of the present invention, a first heat-insulating material layer 27 is provided around the first heating device 25; and a second heat-insulating material layer 28 is provided around the second heating device 26.

[0064] By setting an insulation layer on the outside of the heating device, the slag discharge channel can be kept warm.

[0065] As a preferred embodiment of the present invention, a first lower port is provided at the lower end of the inner channel 21, and a first sealing cover 41 is provided at the first lower port; and / or, a second lower port is provided at the lower end of the outer channel 23, and a second sealing cover 42 is provided at the second lower port; and / or, an upper port is provided at the upper end of the outer channel 23, and a third sealing cover 43 is provided at the upper port; and / or, a fourth sealing cover 44 is provided at the discharge port of the discharge pipe 24.

[0066] By setting up ports and sealing caps, it is easy to clean the residual slag in the slag discharge channel.

[0067] It should be noted that during metal vacuum smelting, all ports of the slag discharge channel need to be sealed with a cover to ensure the vacuum level in the system during furnace start-up or shutdown.

[0068] As a preferred embodiment of the present invention, a first refractory material sealing structure 51 is provided inside the first lower port; and / or, a second refractory material sealing structure 52 is provided inside the second lower port; and / or, a third refractory material sealing structure 53 is provided inside the upper port of the outer channel 23.

[0069] The main function of refractory sealing structures is to seal the channels and prevent high-temperature slag from directly contacting the sealing cover and damaging it.

[0070] As a preferred embodiment of the present invention, the first heating device 25 is a first silicon molybdenum heating rod; and / or, the second heating device 26 is a second silicon molybdenum heating rod.

[0071] It should be noted that the first heating device 25 and the second heating device 26 are preferably, but not limited to, silicon molybdenum heating rods. Other devices that can achieve the same heating effect can also be used instead, and the present invention does not make any special limitation on this.

[0072] As a preferred embodiment of the present invention, the sidewalls of the transition channel 22 and the outer channel 23 each include a graphite layer, a thermal insulation material layer and a steel structure layer from the inside to the outside.

[0073] The sidewalls of the transition channel 22 and the outer channel 23 are respectively composed of a graphite layer, a thermal insulation material layer and a steel structure layer from the inside to the outside, in order to reduce the heat loss of molten slag in the channel during the slag discharge operation.

[0074] As a preferred embodiment of the present invention, a high-temperature resistant adhesive layer is provided between the insulation material layer and the steel structure layer in the transition channel 22 and between the insulation material layer and the steel structure layer in the outer channel 23.

[0075] By providing high-temperature resistant adhesive layers between the insulation material layer and the steel structure layer in the transition channel 22 and between the insulation material layer and the steel structure layer in the outer channel 23, the steel structure layers outside the transition channel 22 and the outer channel 23 are prevented from cracking and compromising the system's airtightness during the heating and cooling process due to the difference in thermal expansion coefficients during furnace start-up or shutdown.

[0076] As a preferred embodiment of the present invention, a movable slag storage device is provided below the discharge port of the discharge pipe 24.

[0077] As a preferred embodiment of the present invention, the mobile slag storage device includes a slag tank 61 disposed below the discharge port of the discharge pipe 24 and a slag tank car 62 disposed below the slag tank 61.

[0078] The mobile slag storage device facilitates the storage and transportation of molten slag.

[0079] As can be seen from the above specific embodiments, the method and apparatus for siphoning slag from a vacuum induction furnace provided by the present invention collects and separates the slag generated in the molten pool through a slag collection and separation device installed above the molten pool of the vacuum induction furnace. The separated slag enters the slag discharge channel from the slag separation port on the side wall of the slag collection hopper. The inner channel and the outer channel are connected by a transition channel. Due to the pressure difference between the slag in the inner channel and the slag discharge port of the outer channel, the slag entering the slag discharge channel is continuously discharged using the siphon principle. The inner channel is heated by an induction coil arranged around the outer periphery of the heating crucible, the transition channel is heated by a first heating device, and the outer channel is heated by a second heating device, so that the temperature of the slag discharge channel is maintained at a preset slag discharge temperature, ensuring the fluidity of the high-viscosity slag in the slag discharge channel, thereby realizing slag-gold separation and continuous slag discharge under vacuum conditions. This effectively solves the problems of poor slag fluidity, difficulty in separating slag and gold, and difficulty in continuous slag discharge under vacuum conditions in the metal smelting process using a vacuum induction furnace in the prior art.

[0080] The method and apparatus for siphoning slag from a vacuum induction furnace to the atmosphere according to the present invention have been described above by way of example with reference to the accompanying drawings. However, those skilled in the art should understand that various modifications can be made to the method and apparatus for siphoning slag from a vacuum induction furnace to the atmosphere according to the present invention without departing from the scope of the invention. Therefore, the scope of protection of the present invention should be determined by the contents of the appended claims.

Claims

1. A method of siphoning slag from a vacuum induction furnace to atmosphere, characterized by, The high-viscosity slag produced by smelting metal in the vacuum induction furnace is continuously discharged outwards by using the siphon slagging device, and the method comprises the following steps: In the process of installing the siphon slagging device on the vacuum induction furnace, The siphon slagging device comprises a slag collecting and separating device and a slagging channel; the slag collecting and separating device is arranged at the upper part of the molten pool of the vacuum induction furnace, and comprises a slag collecting bucket, a metal liquid separating port arranged at the bottom of the slag collecting bucket, and a slag separating port arranged on the side wall of the slag collecting bucket; the slagging channel comprises an inner channel vertically arranged in the side wall of the heating crucible of the vacuum induction furnace, a transition channel communicated with the lower part of the inner channel, and an outer channel connected with the outer port of the transition channel; the lower end of the inner channel penetrates through the heating crucible and is arranged in the vacuum space of the vacuum induction furnace; the inner port of the transition channel is communicated with the lower end of the inner channel, and the outer port is horizontally and upwardly arranged and penetrates through the vacuum space and is arranged outside the vacuum induction furnace; the outer channel is vertically arranged, the lower part is communicated with the outer port of the transition channel, and the upper part is connected with a downwardly inclined discharge pipe; the pressure at the upper part of the inner channel is greater than the pressure at the upper part of the outer channel; a first heating device is arranged on the outer side wall of the transition channel; a second heating device is arranged on the outer side wall of the outer channel; In the process of installing the siphon slagging device on the vacuum induction furnace, In the process of installing the siphon slagging device on the vacuum induction furnace, 2. The method of vacuum induction furnace to atmosphere siphon tapping slag according to claim 1, characterized in that, The first heating device is arranged on the outer side wall of the transition channel; the second heating device is arranged on the outer side wall of the outer channel; the temperature of the slagging channel is kept at a preset slagging temperature by using the inductive coil arranged around the outer periphery of the heating crucible to heat the inner channel, using the first heating device to heat the transition channel, and using the second heating device to heat the outer channel, so that the high-viscosity slag is continuously discharged outwards from the vacuum induction furnace. In the process of installing the siphon slagging device on the vacuum induction furnace, 3. The method of vacuum induction furnace to atmosphere siphon tapping slag according to claim 1, characterized in that, The slag collecting and separating device is arranged at a position 50-100 mm higher than the liquid surface of the slag in the molten pool. In the process of installing the siphon slagging device on the vacuum induction furnace, 4. The method of vacuum induction furnace to atmosphere siphon tapping slag according to claim 1, characterized in that, The inclination angle between the outer port of the transition channel and the horizontal plane is 10-20°.

5. A siphon tapping device for siphon tapping of the slag from a vacuum induction furnace according to any one of claims 1 to 4 into the atmosphere, characterized in that The preset slagging temperature is 1450-1500℃. The siphon slagging device comprises a slag collecting and separating device and a slagging channel; wherein, The slag collecting and separating device is arranged at the upper part of the molten pool of the vacuum induction furnace, and comprises a slag collecting bucket, a metal liquid separating port arranged at the bottom of the slag collecting bucket, and a slag separating port arranged on the side wall of the slag collecting bucket; The slagging channel comprises an inner channel vertically arranged in the side wall of the heating crucible of the vacuum induction furnace, a transition channel communicated with the lower part of the inner channel, and an outer channel connected with the outer port of the transition channel; wherein, The lower end of the inner channel passes through the heating crucible and is arranged in the vacuum space of the vacuum induction furnace; the inner port of the transition channel is communicated with the lower end of the inner channel, and the outer port is arranged transversely and upwardly and passes through the vacuum space and is arranged outside the vacuum induction furnace; the outer channel is arranged vertically, and the lower part is communicated with the outer port of the transition channel, and the upper part is connected with the downwardly inclined discharge pipe; the pressure at the upper slag inlet of the inner channel is greater than the pressure at the upper slag outlet of the outer channel; The first heating device is arranged on the outer side wall of the transition channel; and the second heating device is arranged on the outer side wall of the outer channel.

6. The siphon slagging device according to claim 5, characterized in that, a first lower port is arranged at the lower end of the inner channel, and a first sealing cover is arranged at the first lower port; and / or, a second lower port is arranged at the lower end of the outer channel, and a second sealing cover is arranged at the second lower port; and / or, an upper port is arranged at the upper end of the outer channel, and a third sealing cover is arranged at the upper port; and / or, a fourth sealing cover is arranged at the discharge port of the discharge pipe.

7. The siphon slagging device according to claim 6, characterized in that a first refractory material blocking structure is arranged inside the first lower port; and / or, a second refractory material blocking structure is arranged inside the second lower port; and / or, a third refractory material blocking structure is arranged inside the upper port of the outer channel.

8. The siphon slagging device according to claim 5, characterized in that, the first heating device is a first silicon-molybdenum heating rod; and / or, the second heating device is a second silicon-molybdenum heating rod.

9. The siphon slagging device according to claim 5, characterized in that, the side walls of the transition channel and the outer channel sequentially comprise, from inside to outside, a graphite layer, a thermal insulation material layer and a steel structure layer.

10. The siphon slagging device according to claim 9, characterized in that, a high-temperature-resistant adhesive layer is arranged between the thermal insulation material layer and the steel structure layer of the transition channel and between the thermal insulation material layer and the steel structure layer of the outer channel.

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