Vacuum induction furnace and metal smelting method

Abstract

This invention provides a vacuum induction furnace and a metal smelting method, belonging to the field of metallurgical technology. The apparatus includes a vacuum induction furnace body and a siphon slag removal device disposed on the furnace body. The siphon slag removal device includes a slag collection and separation device and a slag discharge channel. The slag collection and separation device is disposed above the molten pool of the vacuum induction furnace body. The slag discharge channel includes an inner channel vertically disposed inside the side wall of the heating crucible of the vacuum induction furnace body, a transition channel communicating with the lower part of the inner channel, and an outer channel communicating with the outer port of the transition channel. The outer channel is vertically disposed, and its lower part communicates 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 of metal smelting in a vacuum induction furnace, such as poor slag fluidity, difficulty in separating slag and metal, resulting in difficult slag removal, slag-metal mixing, and difficulty in continuous slag discharge under vacuum conditions.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metallurgy, and more particularly to a vacuum induction furnace and a metal smelting method. BACKGROUND

[0002] Metal smelting, such as magnesium smelting technology, is mainly electrolytic and silicon-thermal. Among them, the electrolytic method has a long raw material preparation process, produces a large amount of chlorine gas / sludge by electrolysis, and has a large investment in processing by-products and sludge, thus causing a burden to magnesium production. Typical silicon-thermal methods include the MagneMet method and the Pidgeon method. The former realizes continuous reaction of raw materials under liquid slag, has high reduction efficiency, and short reduction time, but the problem of vacuum sealing of high-temperature electrodes has not been solved, safety is not good, and there is no advantage in cost. The Pidgeon method has simple process equipment, low investment, and low cost, so the crude magnesium produced by the Pidgeon method accounts for more than 80% of the total magnesium production. However, the Pidgeon method has problems such as high energy consumption, low resource utilization efficiency, serious environmental pollution, inability to realize mechanized and automated production, and high carbon emission intensity.

[0003] In view of the above problems existing in the magnesium smelting process, it is an urgent requirement to develop an efficient, environmentally friendly, low-cost, and energy-saving raw magnesium smelting process and equipment to realize industrial upgrading, transformation, and structural adjustment, and to meet the demand for green development. Therefore, based on the transplantation of RH, single nozzle refining furnace, and VD technologies for steelmaking equipment, a vacuum liquid injection smelting method for magnesium (or other metals) is developed. The method sprays calcined white powder into excess reduced silicon-iron liquid to obtain the finished product, and the entire smelting process is continuously supplemented with reduced silicon-iron liquid through a feeding channel. If the slag can be continuously discharged through a slag discharge channel, continuous production of magnesium (or other metals) smelting can be realized, which will be a completely new process. The method has good thermodynamic and kinetic conditions, high reaction speed, higher production capacity than the MagneMet, and significantly lower reduction temperature than the MagneMet method. The cost estimate is lower than the Pidgeon method. However, there is currently no suitable and effective slag discharge method for continuous discharge and slag-gold separation of liquid slag under vacuum conditions. For example, the existing patent CN111270088B discloses a system and method for continuous smelting of magnesium by induction heating and liquid stirring, which provides a scheme for realizing continuous smelting by induction heating and liquid stirring, but does not specifically disclose the design of the slag discharge system. Patent CN117588946A discloses a continuous steel tapping induction melting furnace, which gives a system design for continuous steel tapping of an induction furnace under atmospheric conditions, but does not consider the sealing of the continuous steel tapping process, so it is not suitable for continuous slag discharge under vacuum conditions.

[0004] In summary, the existing vacuum liquid injection smelting method for metals has problems such as difficulty in slag discharge, slag-gold mixing, and difficulty in continuous discharge of molten slag under vacuum conditions due to poor flowability of the molten slag and difficulty in separation of slag-gold.

[0005] It should be noted that the information disclosed in the above background section is only used to strengthen the understanding of the background of the present application, and therefore can include information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY

[0006] In view of the above problems, the purpose of the present application is to provide a vacuum induction furnace and a metal smelting method to solve the problems of the prior art, such as the difficulty of slagging, slag-gold mixing and the difficulty of continuous slagging under vacuum conditions due to the poor flowability of molten slag and the difficulty of slag-gold separation.

[0007] The present application provides a vacuum induction furnace, comprising: a vacuum induction furnace body and a siphon slagging device arranged on the vacuum induction furnace body; wherein,

[0008] The siphon slagging device comprises a molten slag collecting and separating device and a slagging channel;

[0009] The molten slag collecting and separating device is arranged on the upper part of the molten pool of the vacuum induction furnace body, and comprises a molten slag collecting bucket, a metal liquid separating port arranged at the bottom of the molten slag collecting bucket, and a molten slag separating port arranged on the side wall of the molten slag collecting bucket;

[0010] The slagging channel comprises an inner channel vertically arranged inside the side wall of the heating crucible of the vacuum induction furnace body, a transition channel in communication with the lower part of the inner channel, and an outer channel connected with the outer port of the transition channel; wherein,

[0011] The lower end of the inner channel passes through the heating crucible and is arranged in the vacuum space of the vacuum induction furnace body; the inner port of the transition channel is in communication with the lower end of the inner channel, and the outer port is horizontally and upwardly inclined and passes through the vacuum space and is arranged outside the vacuum induction furnace body; the outer channel is vertically arranged, the lower part is in communication 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;

[0012] 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.

[0013] In addition, preferably, 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.

[0014] In addition, preferably, 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.

[0015] In addition, preferably, the inclination angle between the outer port of the transition channel and the horizontal plane is 10-20°.

[0016] In addition, preferably, the first heating device is a first silicon-molybdenum heating rod; and / or the second heating device is a second silicon-molybdenum heating rod.

[0017] In addition, preferably, the molten slag collecting and separating device is arranged at a position 50-100 mm higher than the molten slag liquid level in the molten pool.

[0018] In addition, preferably, a mobile slag storage device is arranged below the discharge port of the discharge pipe.

[0019] In addition, preferably, the mobile slag storage device comprises a slag tank arranged below the discharge port of the discharge pipe and a slag tank car arranged below the slag tank.

[0020] In addition, preferably, the transition channel and the outer channel each comprise, from the inside to the outside, a graphite slagging channel layer, a thermal insulation material layer and a steel structure layer; and / or 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.

[0021] The present application provides a metal vacuum smelting method, which smelts metal by using the vacuum induction furnace as described above, and comprises the following steps:

[0022] In step S1, the metal to be smelted is added into the heating crucible of the vacuum induction furnace body, the heating crucible is heated by using the induction coil arranged outside the heating crucible, so that the metal in the heating crucible is smelted into liquid state, and a molten pool is formed in the heating crucible.

[0023] Step S2, collecting the smelting slag generated in the molten pool by the slag collection and separation device, and separating the collected smelting slag into slag and metal melt by the metal separation port and the slag separation port, so that the separated slag enters the slag discharge channel from the slag separation port on the side wall of the slag collection bucket;

[0024] Step S3, heating the inner channel by the induction coil arranged around the outer periphery of the heating crucible, heating the transition channel by the first heating device, and heating the outer channel by the second heating device, so as to ensure that the temperature of the slag discharge channel remains at a preset slag discharge temperature, so that the high-viscosity smelting slag is continuously discharged from the vacuum induction furnace body.

[0025] Step S4, smelting the metal in the heating crucible to a preset requirement to complete the smelting of the metal to be smelted.

[0026] From the above technical solution, the vacuum induction furnace and the metal smelting method provided by the application, the slag collection and separation device arranged on the upper part of the molten pool of the vacuum induction furnace body is used to collect and separate the smelting slag generated in the molten pool, the separated smelting slag enters the slag discharge channel from the slag separation port on the side wall of the slag collection bucket, the inner channel and the outer channel are communicated by 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, and due to the pressure difference between the smelting slag in the inner channel and the slag outlet of the outer channel, the smelting slag entering the slag discharge channel is continuously discharged by using the siphon principle; the inner channel is heated by the 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, so that the temperature of the slag discharge channel remains at a preset slag discharge temperature, and the flowability of the high-viscosity smelting slag in the slag discharge channel is ensured, so that the slag-metal separation and continuous discharge of smelting slag under vacuum conditions are realized; the problems of difficult slag discharge, slag-metal mixed discharge and difficulty in continuous discharge of smelting slag under vacuum conditions caused by poor flowability of smelting slag and difficulty in slag-metal separation in the process of metal smelting by using the vacuum induction furnace are effectively solved.

[0027] To achieve the above and related objects, one or more aspects of the application include the features described in detail below. The following description and drawings detail certain illustrative aspects of the application. However, these aspects are indicative only of some of the various ways in which the principles of the application can be employed. Also, the application is intended to include all such aspects and their equivalents. BRIEF DESCRIPTION OF DRAWINGS

[0028] Other objects and results of the application will become more apparent and easy to understand by referring to the following description in conjunction with the accompanying drawings.

[0029] Figure 1 Structure diagram of a vacuum induction furnace according to an embodiment of the present application;

[0030] Figure 2 Structure diagram of a part of an inner channel according to an embodiment of the present application;

[0031] Figure 3 Structure diagram of a molten slag collecting and separating device according to an embodiment of the present application;

[0032] Figure 4 Flow chart of a metal vacuum smelting method according to an embodiment of the present application.

[0033] In the drawings, 1 - molten slag collecting and separating device, 11 - molten slag collecting bucket, 12 - molten metal separating port, 13 - molten slag separating port, 21 - inner channel, 22 - transition channel, 23 - outer channel, 24 - discharge pipe, 25 - first heating device, 26 - second heating device, 27 - first heat insulation material layer, 28 - second heat insulation material layer, 31 - vacuum system, 32 - vacuum space, 33 - vacuum shell, 34 - induction coil, 35 - heating crucible, 36 - molten pool, 361 - molten slag, 362 - metal melt, 37 - feeding channel, 41 - first sealing cover, 42 - second sealing cover, 43 - third sealing cover, 44 - fourth sealing cover, 51 - first refractory material plugging structure, 52 - second refractory material plugging structure, 53 - third refractory material plugging structure, 61 - slag ladle, 62 - slag ladle car.

[0034] The same reference numbers in all the drawings indicate similar or corresponding features or functions. DETAILED DESCRIPTION

[0035] In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments. It is apparent, however, that the embodiments can be practiced without these specific details.

[0036] For the prior art proposed in the foregoing, the method of vacuum liquid injection smelting metal has the problems of difficult slagging, slag-metal mixing and difficulty in continuous discharge of molten slag under vacuum conditions due to poor flowability of molten slag and difficulty in slag-metal separation, and a vacuum induction furnace and a metal smelting method are proposed.

[0037] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0038] In order to illustrate the vacuum induction furnace and the metal smelting method provided by the present application, Figure 1 a structure of a vacuum induction furnace according to an embodiment of the present application is shown; Figure 2 a part of an inner channel according to an embodiment of the present application is shown; Figure 3The structure of a slag collection and separation device according to an embodiment of the present invention is shown; Figure 4 The flowchart of a metal vacuum smelting method according to an embodiment of the present invention is shown.

[0039] like Figures 1 to 3 As shown in the figure, the vacuum induction furnace provided by the present invention includes: a vacuum induction furnace body and a siphon slag removal device disposed on the vacuum induction furnace body; wherein,

[0040] The siphon slag removal device includes a slag collection and separation device 1 and a slag discharge channel;

[0041] The slag collection and separation device 1 is installed on the upper part of the molten pool 36 of the vacuum induction furnace body. 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.

[0042] The slag discharge channel includes an inner channel 21 vertically disposed inside the side wall of the heating crucible 35 of the vacuum induction furnace body, 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,

[0043] The lower end of the inner channel 21 passes through the heating crucible 35 and is located in the vacuum space 32 of the vacuum induction furnace body; 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 and is located outside the vacuum induction furnace body; 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 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.

[0044] 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.

[0045] It should be noted that: the vacuum induction furnace body in the application can adopt the mature equipment in the prior art, and the vacuum induction furnace body generally comprises a vacuum space 32 surrounded by a vacuum shell 33, a vacuum connecting hole is formed in the vacuum shell 33 to be connected with a vacuum system 31, so that the internal space of the vacuum shell 33 forms the vacuum space 32. A heating crucible 35 is arranged in the vacuum space 32, an induction coil 34 is arranged outside the heating crucible 35, and a vertical feeding channel 37 is arranged on the inner side wall of the heating crucible 35 to feed the metal raw material into the inside of the heating crucible 35 from the outside. The heating crucible 35 is heated and smelted by the induction coil 34, so that the metal raw material in the inside of the heating crucible 35 is heated and melted to form a molten pool 36. The top of the molten pool 36 is a molten slag 361, and the lower part of the molten slag 361 is a metal melt 362. The smelting slag in the application refers to the molten slag with the metal melt.

[0046] Preferably but not limitedly, the heating crucible 35 is a graphite crucible, and the heating effect is good.

[0047] The feeding channel 37 and the inner channel 21 are vertically arranged in the side wall inside the heating crucible 35. The outer channel 23 is vertically arranged outside the vacuum induction furnace.

[0048] The slag discharge channel in the technical scheme of the application realizes continuous slag discharge by using the siphon principle. By controlling the continuous feeding speed, the molten slag is separated, and then the molten slag is continuously discharged from the inside of the furnace to the outside by using the pressure difference between the molten slag height in the inner channel 21 of the slag discharge channel 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 discharge port in the outer channel 23 (i.e. the discharge port of the outer channel 23 and the discharge pipe 24) and the channel diameter can be calculated according to the Bernoulli equation.

[0049]

[0050] Q≤πr 2 ·V1;

[0051] Wherein, Z1 is the height of the slag discharge port of the outer channel 23, V1 is the slag discharge flow rate of the slag discharge port of the outer channel 23, Z0 is the height of the inner channel 21 (the height of the molten slag in the inner channel 21), V0 is the slag feeding flow rate of the inner channel 21, Z1 and Z0 are both in meters, V1 and V0 are both in meters per second, P0 and P1 are the internal and external pressures of the vacuum induction furnace, both in pascals, ρ is the density of the molten slag, in kilograms per cubic meter 3 g is the acceleration of gravity, in meters per second 2 h w is the total pressure loss of the slag discharge channel, in pascals; Q is the slag discharge amount per unit time, in meters 3r is the radius of the inner channel 21 and the outer channel 23, and the units are m, and the radius of the inner channel 21 and the outer channel 23 is the same.

[0052] The molten slag generated in the molten pool 36 is collected and slag-gold is separated by the slag collecting and separating device 1 arranged at the upper part of the molten pool 36 of the vacuum induction furnace body, the separated molten slag enters the slag discharge channel from the slag separation opening 13 on the side wall of the slag collecting bucket 11, and the inner channel 21 and the outer channel 23 are communicated by the transition channel 22. Since the pressure difference is generated between the molten slag in the inner channel 21 and the slag discharge opening of the outer channel 23, that is, the molten slag entering the slag discharge channel is continuously discharged by using the siphon principle; the inner channel 21 is heated by the inductance coil 34 arranged around the outer periphery of 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 that the temperature of the slag discharge channel is maintained at a predetermined slag discharge temperature, and the flowability of the high-viscosity molten slag in the slag discharge channel is ensured, thereby realizing slag-gold separation and continuous discharge of the molten slag under vacuum condition; effectively solve the problems of difficult slagging, slag-gold mixing and difficult continuous discharge of molten slag under vacuum condition caused by poor flowability of molten slag and difficult separation of slag-gold in the process of metal smelting by using the vacuum induction furnace in the prior art.

[0053] As a preferred scheme of the present application, a first heat preservation material layer 27 is arranged outside the first heating device 25; and a second heat preservation material layer 28 is arranged outside the second heating device 26.

[0054] The heat preservation material layer is arranged outside the heating device to achieve the heat preservation effect of the slag discharge channel.

[0055] As a preferred scheme of the present application, a first lower port is arranged at the lower end of the inner channel 21, and a first sealing cover 41 is arranged at the first lower port; and / or a second lower port is arranged at the lower end of the outer channel 23, and a second sealing cover 42 is arranged at the second lower port; and / or an upper port is arranged at the upper end of the outer channel 23, and a third sealing cover 43 is arranged at the upper port; and / or a fourth sealing cover 44 is arranged at the discharge port of the discharge pipe 24.

[0056] The ports and sealing covers are arranged to facilitate the cleaning of the residual molten slag in the slag discharge channel.

[0057] It should be noted that during the metal vacuum smelting, the ports of the slag discharge channel need to be sealed by the sealing covers to ensure the vacuum degree in the system during the start-up or shutdown period.

[0058] As a preferred scheme of the present application, a first refractory material blocking structure 51 is arranged inside the first lower port; and / or, a second refractory material blocking structure 52 is arranged inside the second lower port; and / or, a third refractory material blocking structure 53 is arranged inside the upper port of the outer channel 23.

[0059] The main function of the refractory material blocking structure is to block the channel and prevent the high-temperature slag from directly contacting the sealing cover.

[0060] As a preferred scheme of the present application, the inclination angle between the outer port of the transition channel 22 and the horizontal plane is 10-20°.

[0061] By setting the inclination angle between the outer port of the transition channel 22 and the horizontal plane to 10-20°, it can be avoided that too much liquid slag remains in the pipeline when the furnace is stopped.

[0062] As a preferred scheme of the present application, 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.

[0063] 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, and other devices capable of achieving the same heating effect can also be used for replacement, which is not particularly limited in the present application

[0064] As a preferred scheme of the present application, the molten slag collecting and separating device 1 is arranged at a position 50-100 mm higher than the liquid surface of the molten slag in the molten pool 36.

[0065] Specifically, the molten slag collecting and separating device 1 collects the molten slag by using the surge and spatter of the molten slag during the molten slag collecting process. The molten slag collected into the molten slag collecting bucket 11 still contains metal liquid (metal melt), and the collected molten slag is separated into molten slag and metal melt by using the metal liquid separation port 12 and the molten slag separation port 13, so that the metal liquid in the molten slag collecting bucket 11 returns to the molten pool 36 from the metal liquid separation port 12 at the bottom thereof, and the molten slag enters the inner channel 21 from the molten slag separation port 13 on the side wall thereof.

[0066] It should be noted that the molten slag collecting and separating device 1 arranged at a position 50-100 mm higher than the liquid surface of the molten slag in the molten pool 36 is a preferred scheme of the present application, and the height of the molten slag collecting and separating device 1 can be determined according to the actual surge or spatter height of the molten slag in actual application, which is not particularly limited in the present application.

[0067] As a preferred scheme of the present application, a mobile slag storage device is arranged below the discharge port of the discharge pipe 24.

[0068] As a preferred scheme of the present application, the mobile slag storage device comprises a slag tank 61 arranged below the discharge port of the discharge pipe 24 and a slag tank truck 62 arranged below the slag tank 61.

[0069] The mobile slag storage device facilitates the storage and delivery of molten slag.

[0070] As a preferred scheme of the present application, the transition channel 22 and the outer channel 23 each comprise, from inside to outside, a graphite slag discharge channel layer, a thermal insulation material layer and a steel structure layer; and / or,

[0071] A high-temperature-resistant adhesive layer is arranged between the thermal insulation material layer and the steel structure layer of the transition channel 22 and between the thermal insulation material layer and the steel structure layer of the outer channel 23.

[0072] The side walls of the transition channel 22 and the outer channel 23 each comprise, in sequence from inside to outside, a graphite layer, a thermal insulation material layer and a steel structure layer, so as to reduce the heat loss of molten slag in the channels during slag discharge operation.

[0073] By arranging the high-temperature-resistant adhesive layer between the thermal insulation material layer and the steel structure layer of the transition channel 22 and between the thermal insulation material layer and the steel structure layer of the outer channel 23, the cracking of the steel structure layer of the transition channel 22 and the outer channel 23 due to different thermal expansion coefficients during heating and cooling is prevented during furnace start-up or shutdown, so as to maintain the system airtightness.

[0074] As shown in Figure 4 The metal vacuum smelting method provided by the present application comprises the following steps:

[0075] In step S1, the metal to be smelted is added into the heating crucible 35 of the vacuum induction furnace body, and the induction coil 34 arranged around the outside of the heating crucible 35 is used to heat the heating crucible 35, so that the metal in the heating crucible 35 is smelted into a liquid state, and a molten pool is formed in the heating crucible 35;

[0076] In step S2, the smelting slag generated in the molten pool 36 is collected by the slag collection and separation device 1, and the collected smelting slag is separated into molten slag and metal melt by using the metal liquid separation port 12 and the molten slag separation port 13, so that the separated molten slag enters the slag discharge channel from the molten slag separation port 13;

[0077] In step S3, the inner channel 21 is heated by using the induction coil 34 arranged around the periphery of the heating crucible 35, the transition channel 22 is heated by using the first heating device 25, and the outer channel 23 is heated by using the second heating device 26, so as to ensure that the temperature of the slag discharge channel remains at a preset slag discharge temperature, and the high-viscosity molten slag is continuously discharged from the vacuum induction furnace body.

[0078] Step S4, smelting the metal in the heated crucible to a preset requirement to complete smelting of the metal to be smelted.

[0079] As a preferred scheme of the present application, the preset slagging temperature is 1450-1500℃.

[0080] It should be noted that the preset slagging temperature is preferably but not limited to 1450-1500℃, and can be limited according to the temperature at which the actual metal smelting slag keeps fluidity. For most metal smelting slag, 1450-1500℃ can ensure the fluidity of the smelting slag.

[0081] As can be seen from the above specific embodiments, the vacuum induction furnace and the metal smelting method provided by the present application have the following advantages. The molten slag produced in the molten pool is collected and slag-gold separated by the slag collecting and separating device arranged at the upper part of the molten pool of the vacuum induction furnace body. The separated molten slag enters the slagging channel from the slag separating port on the sidewall of the slag collecting bucket. The inner channel and the outer channel are communicated by the transition channel. Since a pressure difference is generated between the molten slag in the inner channel and the slagging port of the outer channel, the molten slag entering the slagging channel is continuously discharged by using the siphon principle. The inner channel is heated by the inductive 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, so that the temperature of the slagging channel is kept at the preset slagging temperature, ensuring the fluidity of the high-viscosity molten slag in the slagging channel, thereby realizing slag-gold separation and continuous discharge of the molten slag under vacuum conditions. The problems of difficult slagging, slag-gold mixing, and difficulty in continuous discharge of the molten slag under vacuum conditions caused by poor fluidity of the molten slag and difficulty in slag-gold separation in the process of metal smelting by using the vacuum induction furnace in the prior art are effectively solved.

[0082] The vacuum induction furnace and the metal smelting method according to the present application are described above with reference to the accompanying drawings by way of example. However, those skilled in the art should understand that various improvements can be made to the above-mentioned vacuum induction furnace and metal smelting method according to the present application without departing from the content of the present application. Therefore, the protection scope of the present application should be determined by the content of the appended claims.

Claims

1. A vacuum induction furnace, characterized in that, The vacuum induction furnace comprises a vacuum induction furnace body and a siphon slagging device arranged on the vacuum induction furnace body; wherein, the siphon slagging device comprises a molten slag collecting and separating device and a slagging channel; the molten slag collecting and separating device is arranged at the upper part of the molten pool of the vacuum induction furnace body, and comprises a molten slag collecting bucket, a molten metal separating port arranged at the bottom of the molten slag collecting bucket, and a molten slag separating port arranged on the sidewall of the molten slag collecting bucket; the slagging channel comprises an inner channel vertically arranged inside the sidewall of the heating crucible of the vacuum induction furnace body, a transition channel in communication 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 penetrates through the heating crucible and is arranged in the vacuum space of the vacuum induction furnace body; the inner port of the transition channel is in communication 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 body; the outer channel is vertically arranged, the lower part is in communication 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 slagging port of the outer channel is greater than the pressure at the upper slagging port of the outer channel; a first heating device is arranged on the outer sidewall of the transition channel; and a second heating device is arranged on the outer sidewall of the outer channel.

2. The vacuum induction furnace according to claim 1, wherein, 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.

3. The vacuum induction furnace according to claim 2, wherein, 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.

4. The vacuum induction furnace according to claim 1, wherein, the inclination angle between the outer port of the transition channel and the horizontal plane is 10-20°.

5. The vacuum induction furnace according to claim 1, wherein, the first heating device is a first silicon-molybdenum heating rod; and / or, the second heating device is a second silicon-molybdenum heating rod.

6. The vacuum induction furnace according to claim 1, wherein, the molten slag collecting and separating device is arranged at a position 50-100 mm higher than the molten slag liquid level in the molten pool.

7. The vacuum induction furnace according to claim 1, wherein, a mobile slag storage device is arranged below the discharge port of the discharge pipe.

8. The vacuum induction furnace according to claim 7, wherein, the mobile slag storage device comprises a slag tank arranged below the discharge port of the discharge pipe and a slag tank car arranged below the slag tank. ​ 9. The vacuum induction furnace according to claim 1, characterized in that, the transition channel and the outer channel each comprise, from inside to outside, a graphite slagging channel layer, a heat insulation material layer and a steel structure layer; and / or, a high-temperature resistant adhesive layer is arranged between the heat insulation material layer and the steel structure layer of the transition channel and between the heat insulation material layer and the steel structure layer of the outer channel.

10. A method of vacuum melting a metal, characterized by, A method for smelting metal by using the vacuum induction furnace according to any one of claims 1-9, comprising the following steps: Step S1, adding the metal to be smelted into the heating crucible of the vacuum induction furnace body, heating the heating crucible by using the induction coil arranged outside the heating crucible, so that the metal in the heating crucible is smelted into liquid state, and a molten pool is formed in the heating crucible; Step S2, collecting the smelting slag generated in the molten pool by the slag collecting and separating device, and separating the collected smelting slag into molten slag and metal melt by using the metal liquid separating port and the molten slag separating port, so that the separated molten slag enters the slagging channel from the molten slag separating port; Step S3, heating the inner channel by using the induction coil arranged around the periphery of the heating crucible, heating the transition channel by using the first heating device, and heating the outer channel by using the second heating device, so as to ensure that the temperature of the slagging channel maintains a preset slagging temperature, so that the high-viscosity molten slag is continuously discharged outward from the vacuum induction furnace body; Step S4, smelting the metal in the heating crucible to a preset requirement, so as to complete the smelting of the metal to be smelted.

Images