A process for melting and cleaning an aluminum alloy

Abstract

The present application relates to a kind of aluminum alloy smelting impurity removal process, comprising the following steps: aluminum alloy solution is added into smelting furnace body, the bottom of the smelting furnace body is provided with the circular table cavity of big up small down, the circular table cavity is provided with air jet disc, the air jet disc is communicated with external gas source by hard gas pipe;The present application relates to the field of aluminum alloy smelting technology.This kind of aluminum alloy smelting impurity removal process realizes the uniform distribution and efficient contact of inert gas: by setting the circular table cavity of big up small down in the bottom of smelting furnace body, and installing disc-shaped air jet disc therein, after inert gas is sprayed from multiple air jet ports, it diffuses upwards along the inner wall of circular table cavity, gas is fan-shaped, substantially increases the contact area and contact time of bubble and aluminum liquid, significantly improves hydrogen removal and inclusion floatation efficiency.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy smelting technology, specifically to an aluminum alloy smelting and impurity removal process. Background Technology

[0002] During aluminum alloy smelting, molten aluminum easily contains impurities such as hydrogen, non-metallic inclusions (e.g., alumina), and intermetallic compounds. These impurities significantly reduce the density, mechanical properties, and corrosion resistance of castings. Traditional impurity removal methods mainly employ gas blowing refining (introducing inert gases such as argon or nitrogen) and mechanical stirring. However, existing technologies have significant drawbacks: First, gas blowing devices are mostly single-pipe or annular pipes, resulting in uneven gas distribution, large bubble size, rapid rising speed, short contact time with molten aluminum, and low impurity removal efficiency. Second, mechanical stirring usually requires a rotating shaft to extend into the molten aluminum; the dynamic seal between the shaft and the furnace body is prone to leakage at high temperatures, causing gas ingress or oxidation of the molten aluminum, and the stirring blades are susceptible to corrosion. Furthermore, in traditional equipment, gas blowing and stirring are often independent operations with poor coordination, making it difficult to achieve an ideal melt flow state. Therefore, there is an urgent need in this field for an aluminum alloy smelting impurity removal process that features uniform gas distribution, reliable stirring and sealing, and coordinated blowing and stirring. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides an aluminum alloy smelting and impurity removal process, which solves the problems mentioned above.

[0004] To achieve the above objectives, the present invention provides the following technical solution: an aluminum alloy smelting and impurity removal process, comprising the following steps: adding an aluminum alloy solution into a smelting furnace body, wherein the bottom of the smelting furnace body is provided with a frustum-shaped cavity that is larger at the top and smaller at the bottom, and a jet plate is provided inside the frustum-shaped cavity, the jet plate being connected to an external gas source through a rigid gas pipe; introducing inert gas into the jet plate through the rigid gas pipe, causing the inert gas to be ejected from multiple jet nozzles on the surface of the jet plate to purge the aluminum alloy solution inside the frustum-shaped cavity; simultaneously, activating a drive motor fixed in the power chamber of the rigid gas pipe, which drives two repulsive magnets to rotate, thereby driving a collar fitted on the surface of the rigid gas pipe and having repulsive magnetic poles to rotate, which in turn drives a stirring rod fixed on the surface of the collar to rotate, thus stirring the aluminum alloy solution.

[0005] As a further aspect of the present invention, the inert gas is argon or nitrogen.

[0006] As a further aspect of the present invention: in the purging step, after the inert gas is ejected from the jet disk, it diffuses upward along the inner wall of the frustum cavity, increasing the contact time and contact area with the aluminum alloy solution.

[0007] As a further aspect of the present invention, it also includes the step of discharging the waste gas generated during purging and reaction through a vacuum pipe located at the top of the melting furnace.

[0008] As a further aspect of the present invention: when the drive motor drives the two repulsive magnets to rotate, the alternating action of repulsion and attraction forces drives the collar and stirring rod to rotate continuously in a non-contact manner, thereby achieving dynamic stirring of the aluminum alloy solution.

[0009] As a further aspect of the present invention: the purging and the stirring are carried out simultaneously during the aluminum alloy smelting process, and the rotation of the stirring rod is achieved through magnetic non-contact transmission to maintain the sealing of the inside of the smelting furnace.

[0010] Compared with the prior art, the present invention has the following advantages: Uniform distribution and efficient contact of inert gas are achieved: By setting a frustum-shaped cavity with a larger upper part and a smaller lower part at the bottom of the melting furnace body, and installing a disc-shaped jet plate in it, the inert gas is ejected from multiple jet ports and diffuses upward along the inner wall of the frustum-shaped cavity. The gas spreads out in a fan shape, which greatly increases the contact area and contact time between the bubbles and the aluminum liquid, and significantly improves the efficiency of hydrogen removal and inclusion flotation.

[0011] Non-contact magnetic drive stirring is employed to ensure the furnace's airtightness: a drive motor in the power chamber inside the rigid gas pipe rotates two repulsive magnets, which in turn drive a collar with repulsive magnetic poles, fitted onto the surface of the rigid gas pipe, and a stirring rod to rotate synchronously. There is no mechanical contact between the transmission components, completely avoiding dynamic seal leakage and ensuring the furnace's internal airtightness, preventing aluminum oxidation and gas escape.

[0012] The system achieves a synergistic dynamic effect of blowing and stirring: the blowing and stirring processes occur simultaneously during aluminum alloy melting. Inert gas is injected from the bottom and dispersed by the rotating stirring rod during its ascent, forming microbubbles that are evenly distributed throughout the molten aluminum pool by the eddies generated by stirring. This synergistic effect greatly enhances mass transfer between the gas, liquid, and solid phases, enabling non-metallic inclusions to be more effectively adsorbed by the bubbles and float to the liquid surface, while simultaneously accelerating the diffusion and removal of hydrogen.

[0013] The process is simple and the equipment is highly integrated: the entire impurity removal process only requires the introduction of inert gas and the start of the drive motor, without the need for complex auxiliary equipment. The vacuum pipeline allows for the timely discharge of waste gases generated during purging and reaction, maintaining a slightly negative or positive pressure environment inside the furnace. The support base provides stable rotational support for the collar. This process is easy to automate and is suitable for continuous production. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a cross-sectional view of the structure of the present invention; Figure 3 This is a schematic diagram of the rigid air tube of the present invention; Figure 4 For the present invention Figure 3 A magnified view of a portion of point A in the middle.

[0015] In the diagram: 1. Melting furnace body; 2. Vacuum pipe; 3. Rigid gas pipe; 4. Power chamber; 5. Jet disc; 7. Stirring rod; 8. Drive motor; 9. Support base; 10. Magnet; 11. Collar; 13. Frustum cavity. Detailed Implementation

[0016] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0017] Please see Figure 1-4 This invention provides a technical solution: an aluminum alloy smelting and impurity removal process, comprising the following steps: adding an aluminum alloy solution into a smelting furnace body 1, the bottom of the smelting furnace body 1 being provided with a frustum cavity 13 that is larger at the top and smaller at the bottom, a jet plate 5 being provided inside the frustum cavity 13, the jet plate 5 being connected to an external gas source through a rigid gas pipe 3; introducing inert gas into the jet plate 5 through the rigid gas pipe 3, causing the inert gas to be ejected from multiple jet nozzles on the surface of the jet plate 5, purging the aluminum alloy solution inside the frustum cavity 13; simultaneously, starting a drive motor 8 fixed in the power chamber 4 inside the rigid gas pipe 3, the drive motor 8 driving two repulsive magnets 10 to rotate, driving a collar 11 fitted on the surface of the rigid gas pipe 3 and having repulsive magnetic poles to rotate through magnetic repulsion, thereby driving a stirring rod 7 fixed on the surface of the collar 11 to rotate, stirring the aluminum alloy solution.

[0018] The inert gas is argon or nitrogen.

[0019] During the purging process, the inert gas is ejected from the jet disk 5 and diffuses upward along the inner wall of the frustum cavity 13, increasing the contact time and contact area with the aluminum alloy solution.

[0020] It also includes the step of discharging the waste gas generated during purging and reaction through a vacuum pipe 2 located at the top of the smelting furnace body 1.

[0021] When the drive motor 8 drives the two repulsive magnets 10 to rotate, the alternating action of repulsion and attraction forces pushes the collar 11 and the stirring rod 7 to rotate continuously in a non-contact manner, thereby achieving dynamic stirring of the aluminum alloy solution.

[0022] The purging and stirring are carried out simultaneously during the aluminum alloy smelting process, and the rotation of the stirring rod 7 is achieved through magnetic non-contact transmission to maintain the sealing of the inside of the smelting furnace 1.

[0023] The impurity removal equipment includes a smelting furnace body 1. An air blowing mechanism is installed inside the smelting furnace body 1. The air blowing mechanism includes a rigid air pipe 3 fixed to the top of the smelting furnace body 1. The bottom end of the rigid air pipe 3 penetrates and is installed inside the smelting furnace body 1. An air jet disc 5 is connected to the end of the rigid air pipe 3 within the smelting furnace body 1. The air jet disc 5 is disc-shaped and has multiple air jets evenly distributed on its surface. A frustum-shaped cavity 13, larger at the top and smaller at the bottom, is opened at the bottom of the smelting furnace body 1 to fit the air jet disc 5. A protruding power chamber 4 is opened inside the rigid air pipe 3. A drive motor 8 is fixedly connected to the inner cavity of the power chamber 4. Two repulsive magnets 10 are fixedly connected to one end of the output shaft of the drive motor 8. A collar 11 located outside the magnets 10 is rotatably connected to the surface of the rigid air pipe 3. A stirring rod 7 is fixedly connected to the surface of the ring 11. Two repulsive magnetic poles are provided in the inner cavity of the ring 11. A support seat 9 located below the ring 11 is fixedly connected to the surface of the rigid gas pipe 3. A vacuum pipe 2 is provided at the top of the smelting furnace body 1 for exhausting waste gas. When in use, the aluminum alloy solution enters the interior of the smelting furnace body 1. Inert gas is blown in through the rigid gas pipe 3 and sprayed out through the jet nozzle of the jet plate 5 to purge the solution. The frustum cavity 13 can fully contact the solution. During purging, the two magnets 10 are driven to rotate by the drive motor 8. The repulsive and attractive forces push the ring 11 to rotate on the outside, driving the stirring rod 7 to rotate for stirring. This can effectively seal the components, and the transmission components do not contact each other.

[0024] When using this invention, the first stage is: adding materials and preparation. Pour or pump the molten aluminum alloy solution into the melting furnace 1, ensuring the molten aluminum level submerges the jet plate 5 and stirring rod 7. Start the external gas source, introducing inert gas such as argon or nitrogen into the jet plate 5 through the rigid gas pipe 3, and simultaneously start the drive motor 8.

[0025] Second stage: Inert gas purging Inert gas is uniformly ejected from multiple nozzles on the surface of the jet plate 5. Because the bottom of the melting furnace has a frustum-shaped cavity 13 (larger at the top and smaller at the bottom), the ejected gas is guided by the cavity wall and diffuses obliquely upwards, forming a fan-shaped bubble flow. During its ascent, the bubbles come into full contact with the molten aluminum, allowing hydrogen atoms in the molten aluminum to diffuse into the bubbles. Simultaneously, non-metallic inclusions such as alumina film are adsorbed onto the bubble surface and float to the surface along with the bubbles.

[0026] Phase 3: Non-contact magnetic stirring Simultaneously with the blowing, the drive motor 8 starts, and its output shaft drives two repulsive magnets 10 to rotate at high speed. Since the inner cavity of the collar 11 also has repulsive magnetic poles, and the collar is stably supported by the support base 9 on the surface of the rigid air tube 3, when the external magnet rotates, the magnetic repulsion pushes the collar and the stirring rod 7 fixed to its surface to rotate synchronously. By controlling the speed and direction of the drive motor, the stirring rod can be rotated in both directions or at varying speeds. The eddy currents generated by the rotating stirring rod break up and disperse the bubbles ejected from the bottom, distributing them evenly throughout the molten aluminum pool, significantly extending the residence time of the bubbles in the molten aluminum and improving the impurity removal efficiency.

[0027] Phase 4: Exhaust Gas Discharge and Impurity Removal The exhaust gases generated during purging and reaction, containing hydrogen, water vapor, and a small amount of oxide dust, are drawn out or discharged through vacuum pipe 2 located at the top of the smelting furnace, maintaining a suitable pressure environment inside the furnace. Inclusions that float to the liquid surface form slag, which can be removed through conventional slag removal operations.

[0028] Phase 5: End of Process Once the preset purging and stirring time has been reached, turn off the inert gas and drive motor, let it stand for a moment to allow the molten aluminum to stabilize, and then proceed with subsequent casting or transfer operations.

[0029] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A process for removing impurities during aluminum alloy smelting, characterized in that: Includes the following steps: The aluminum alloy solution is added to the smelting furnace body (1) of the impurity removal equipment. The bottom of the smelting furnace body (1) is provided with a frustum cavity (13) that is larger at the top and smaller at the bottom. A jet plate (5) is provided in the frustum cavity (13). The jet plate (5) is connected to an external gas source through a rigid gas pipe (3). Inert gas is introduced into the jet plate (5) through the rigid gas pipe (3), so that the inert gas is sprayed out from multiple jet ports on the surface of the jet plate (5) to purge the aluminum alloy solution in the frustum cavity (13). At the same time, the drive motor (8) fixed in the power chamber (4) of the rigid gas pipe (3) is started. The drive motor (8) drives two repulsive magnets (10) to rotate. The magnetic repulsion drives the collar (11) sleeved on the surface of the rigid gas pipe (3) and with repulsive magnetic poles to rotate, thereby driving the stirring rod (7) fixed on the surface of the collar (11) to rotate and stir the aluminum alloy solution.

2. The aluminum alloy smelting and impurity removal process according to claim 1, characterized in that: The inert gas is argon or nitrogen.

3. The aluminum alloy smelting and impurity removal process according to claim 1, characterized in that: During the purging step, the inert gas is ejected from the jet disk (5) and diffuses upward along the inner wall of the frustum cavity (13), increasing the contact time and contact area with the aluminum alloy solution.

4. The aluminum alloy smelting and impurity removal process according to claim 1, characterized in that: It also includes the step of discharging the waste gas generated during purging and reaction through a vacuum pipe (2) located at the top of the smelting furnace body (1).

5. The aluminum alloy smelting and impurity removal process according to claim 1, characterized in that: When the drive motor (8) drives the two repulsive magnets (10) to rotate, the alternating action of repulsion and attraction forces pushes the collar (11) and stirring rod (7) to rotate continuously in a non-contact manner, thereby achieving dynamic stirring of the aluminum alloy solution.

6. The aluminum alloy smelting and impurity removal process according to claim 1, characterized in that: The purging and stirring are carried out simultaneously during the aluminum alloy smelting process, and the rotation of the stirring rod (7) is achieved through magnetic non-contact transmission to maintain the sealing of the inside of the smelting furnace (1).

Images