Tin metal ingot casting device and method

Abstract

The invention relates to the technical field of non-ferrous metal smelting, in particular to a tin metal ingot casting device and method. Comprising a refining pot and a transfer barrel, the side face of the refining pot is communicated with a first liquid discharge pipe, a first liquid discharge valve is arranged on the first liquid discharge pipe, the first liquid discharge pipe extends into the transfer barrel, the side face of the transfer barrel is communicated with a second liquid discharge pipe, a second liquid discharge valve is arranged on the second liquid discharge pipe, the side face of a protective gas storage tank is connected with a gas outlet pipe, and a gas outlet valve is arranged on the gas outlet pipe. The ingot casting device further comprises an ingot casting module, the liquid outlet end of the second liquid discharging pipe faces the interior of an ingot casting groove of the ingot casting module, and heating devices are arranged on the first liquid discharging pipe and the transfer barrel. The tin liquid is prevented from being oxidized in the transportation process through the protective gas and the heating constant-temperature equipment, so that the qualification rate of tin metal ingots is increased.

Description

Technical Field

[0001] This invention relates to the field of non-ferrous metal smelting technology, and in particular to a tin ingot casting apparatus and method. Background Technology

[0002] Tin metal is widely used in the manufacture of electronic devices and alloys. Tin has a relatively low melting point of 231.96℃. At room temperature, tin is relatively stable and almost unaffected by air because a dense oxide film forms on its surface, preventing oxidation. However, when the temperature of molten tin exceeds 150℃, a large amount of tin reacts with air to form tin oxide and stannous oxide, resulting in a large amount of gray oxide slag on the surface of the molten tin.

[0003] Therefore, reducing secondary oxidation of tin metal is crucial in the tin smelting industry, especially during the refined tin ingot casting stage. The ingot temperature is controlled at 340℃, which results in a large amount of oxide slag remaining on the surface of the molten tin for a long time. Whether the molten tin is directly discharged or scooped out, it will come into direct contact with oxygen during transportation, leading to tin oxidation and a high content of oxide slag in the molten tin, resulting in substandard refined tin products. Therefore, solving the oxidation problem in the molten tin ingot casting process is of paramount importance. Summary of the Invention

[0004] To address the problem of tin oxidation and high slag content in molten tin due to direct contact with oxygen during transportation, this invention proposes a tin ingot casting device and method. By using protective gas and heating constant temperature equipment, oxidation of molten tin during transportation is avoided, thereby improving the yield of tin ingots.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows: A tin ingot casting apparatus includes a refining pot and a transfer tank, as well as a protective gas storage tank and an ingot casting module. A first discharge pipe is connected to the side of the refining pot, and a first discharge valve is provided on the first discharge pipe. The end of the first discharge pipe away from the refining pot extends into the transfer tank from the upper end of the transfer tank. The transfer tank is rotatably mounted on a base at its lower end. A second discharge pipe is connected to the side of the transfer tank, and a second discharge valve is provided on the second discharge pipe. The connection between the first discharge pipe and the transfer tank is located at the center of the upper end of the transfer tank.

[0006] A gas outlet pipe is connected to the side of the protective gas storage tank. A gas outlet valve is installed on the gas outlet pipe. The end of the gas outlet pipe away from the protective gas storage tank is connected to the first liquid discharge pipe. The connection between the gas outlet pipe and the first liquid discharge pipe is located on the side of the first liquid discharge valve away from the refining pot. A pressure gauge is also installed on the first liquid discharge pipe. The outlet end of the second discharge pipe faces the ingot casting tank of the ingot casting module, and both the first discharge pipe and the transfer tank are equipped with heating devices. The heating devices ensure the temperature of the molten tin during casting.

[0007] Preferably, the connection between the first discharge pipe and the refining pot is located on the lower side of the refining pot. The oxide slag is located on the upper surface of the molten tin.

[0008] Preferably, a sealing ring is provided at the connection between the transfer tank and the first discharge pipe, and the first discharge pipe extends into the transfer tank through the sealing ring. This prevents external air from re-entering the transfer tank.

[0009] Preferably, an electric heating wire is wound around the first discharge pipe, and a heat preservation heater is provided on the outside of the transfer tank.

[0010] Preferably, the lower end of the transfer barrel is fixed with a rotating shaft, which is rotatably mounted on the base. The casting device also includes a motor, the output of which drives the rotating shaft to rotate.

[0011] Preferably, the ingot casting module includes a first module, a second module, and multiple molds. Both the first and second modules are arc-shaped. The first module has multiple uniformly spaced first through slots, and the second module has multiple uniformly spaced second through slots. Each first and second through slot corresponds vertically. The upper end of each mold extends into a first through slot, and the lower end extends into a second through slot. The second through slot is U-shaped, and the lower end of the mold matches the shape of the second through slot. The first and second modules are fixedly connected. This facilitates subsequent demolding of the tin ingot.

[0012] Preferably, the ingot casting module is provided with a support base on its lower side, a support rod is fixed on the support base, and a telescopic mechanism is hinged to the support base. The support rod is located at the end of the ingot casting module and is hinged to the ingot casting module, and the telescopic mechanism is located on the lower side of the ingot casting module and is hinged to the ingot casting module.

[0013] Preferably, a telescopic mechanism is provided on the lower side of the support base.

[0014] The beneficial effects of the present invention through the above technical solution are as follows: 1. Before casting, the present invention introduces protective gas into the first discharge pipe and the transfer tank through a protective gas storage tank to purge the air from the first discharge pipe and the transfer tank. The second discharge valve is then closed to fill the first discharge pipe and the transfer tank with protective gas, thereby preventing the molten tin from coming into contact with air during the discharge process and avoiding its oxidation. At the same time, the first discharge pipe and the transfer tank are heated by a heating device to ensure the casting temperature of the molten tin, thereby improving the yield of tin ingots.

[0015] 2. The ingot casting module of the present invention includes a first module, a second module and multiple molds. The molten tin falls into the ingot casting groove in the mold. The ingot casting module can be tilted at a certain angle under the control of the telescopic mechanism. The bottom of the mold can be directly struck by a person to facilitate the tin metal ingot to fall out of the mold. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a tin metal ingot casting device according to the present invention; Figure 2 This invention relates to a tin ingot casting apparatus. Figure 1 Enlarged view of the structure in the image; Figure 3 This is a schematic diagram of the ingot casting module and support base of a tin metal ingot casting device according to the present invention; Figure 4 This is a cross-sectional view of the ingot casting module of a tin metal ingot casting device according to the present invention.

[0017] In the attached diagram, the following numbers are used: 1 is the refining pot, 2 is the transfer tank, 3 is the first discharge pipe, 4 is the first discharge valve, 5 is the base, 6 is the second discharge pipe, 7 is the second discharge valve, 8 is the protective gas storage tank, 9 is the gas outlet pipe, 10 is the gas outlet valve, 11 is the pressure gauge, 12 is the sealing ring, 13 is the rotating shaft, 14 is the bearing seat, and 15 is the sprocket. 21 is the first module, 22 is the second module, 23 is the mold, 231 is the ingot casting groove, 24 is the support base, 25 is the support rod, 251 is the first hinge base, 26 is the telescopic mechanism, and 261 is the second hinge base. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and specific embodiments: Example 1 like Figures 1-4 As shown, this embodiment provides a tin ingot casting device, including a refining pot 1 and a transfer tank 2. A first discharge pipe 3 is connected to the side of the refining pot 1. The connection between the first discharge pipe 3 and the refining pot 1 is located on the lower side of the refining pot 1. The tin is discharged from the bottom of the refining pot 1 to avoid the tin liquid from being mixed with oxide slag on the surface of the tin liquid.

[0019] The first discharge pipe 3 is equipped with a first discharge valve 4. The end of the first discharge pipe 3 away from the refining pot 1 extends into the transfer tank 2 from the upper end of the transfer tank 2. The transfer tank 2 is a hollow cylinder. The connection between the first discharge pipe 3 and the upper end of the transfer tank 2 is located at the center of the upper end of the transfer tank 2. A sealing ring 12 is fixedly installed at the connection between the transfer tank 2 and the first discharge pipe 3 (see reference). Figure 2 The first discharge pipe 3 extends into the transfer tank 2 through the sealing ring 12 to prevent air from entering the transfer tank 2 through this connection.

[0020] The transfer barrel 2 is rotatably mounted on the base 5 at its lower end. A rotating shaft 13 is fixed to the lower end of the transfer barrel 2. The rotating shaft 13 is rotatably mounted on the base 5. A bearing seat 14 is fixed on the base 5. A bearing is installed in the bearing seat 14. The rotating shaft 13 passes through the bearing and is rotatably mounted on the base 5. The ingot casting device also includes a motor (not shown in the figure). The output end of the motor drives the rotating shaft 13 to rotate. A sprocket is fixed on the output end of the motor. The sprocket on the output end of the motor and the sprocket on the rotating shaft 13 are connected by a transmission chain to realize the rotation of the rotating shaft 13 driven by the motor.

[0021] The side of the transfer tank 2 is connected to the second discharge pipe 6, and the second discharge pipe 6 is equipped with a second discharge valve 7. The refining pot 1, the transfer tank 2, the first discharge pipe 3 and the second discharge pipe 6 are all made of 316L stainless steel to ensure that the molten tin will not be contaminated during the ingot casting process.

[0022] Furthermore, the ingot casting device also includes a protective gas storage tank 8. In this embodiment, nitrogen is used as the protective gas. A gas outlet pipe 9 is connected to the side of the protective gas storage tank 8. A gas outlet valve 10 is provided on the gas outlet pipe 9. The end of the gas outlet pipe 9 away from the protective gas storage tank 8 is connected to the first liquid discharge pipe 3. The connection between the gas outlet pipe 9 and the first liquid discharge pipe 3 is located on the side of the first liquid discharge valve 4 away from the refining pot 1. A pressure gauge 11 is also provided on the first liquid discharge pipe 3. By opening the gas outlet valve 10, nitrogen is introduced into the first liquid discharge pipe 3 and the transfer tank 2. The nitrogen pressure is maintained at 0.8 MPa to purge the air inside and prevent the molten tin from contacting the air during transportation.

[0023] During production, after the air inside the first drain pipe 3 and the transfer tank 2 is purged, the protective gas storage tank 8 is not completely closed. This is because the first drain pipe 3 and the transfer tank 2 are not completely sealed and will leak air. Therefore, it is necessary to ensure the pressure of the protective gas inside the first drain pipe 3 and the transfer tank 2.

[0024] Further, refer to Figure 3 and Figure 4The ingot casting device also includes an ingot casting module. The outlet end of the second liquid discharge pipe 6 faces the ingot casting groove 231 of the ingot casting module. Specifically, the ingot casting module includes a first module 21, a second module 22, and nine molds 23. The cross-sections of the first module 21 and the second module 22 are both arc-shaped. Nine first through slots are evenly distributed on the first module 21, and nine second through slots are evenly distributed on the second module 22. Each first through slot and each second through slot are vertically aligned. The first through slots penetrate the first mold. Group 21 connects the upper and lower sides of the first module 21. The second through groove passes through the second module 22 and connects the upper and lower sides of the second module 22. The upper end of the mold 23 extends into the first through groove and the lower end extends into the second through groove. The upper end of the mold 23 is flush with the upper side of the first module 21 and the lower end is flush with the lower side of the second module 22. The second through groove is U-shaped. The lower end of the mold 23 matches the shape of the second through groove. The first module 21 and the second module 22 are fixedly connected by bolts.

[0025] During the ingot casting module installation process, multiple molds 23 are first placed into multiple second through slots of the second module 22, and then the first module 21 is placed on the upper side of the second module 22. The upper end of the mold 23 extends into the first through slot of the first module 21. At this time, the first module 21 and the second module 22 are fixed by bolts. After the tin metal ingot cools and solidifies, the lower end of the mold 23 can be directly struck by a person to make the metal ingot in the mold fall out.

[0026] Furthermore, a support base 24 is provided on the lower side of the ingot casting module. A support rod 25 is welded and fixed on the support base 24. A telescopic mechanism 26 is hinged on the support base 24. The telescopic mechanism 26 is a hydraulic cylinder or a pneumatic cylinder. Its lower end is hinged to the hinge shaft on the support base 24 (not shown in the figure). The support rod 25 is located at the end of the ingot casting module and is hinged to the ingot casting module. In this embodiment, hinge blocks are fixed at both ends of the first module 21, and a first hinge seat 251 is fixed at the upper end of the two support rods 25. The first hinge seat 251 and the hinge block are hinged through a hinge shaft. The telescopic mechanism 26 is located on the lower side of the ingot module and is hinged to the ingot module. The lower end of the telescopic mechanism 26 on the support base 24 is hinged to the support base 24, and the upper end is hinged to the hinge block fixed on the lower side of the second module 22 through the second hinge seat 261. This enables the ingot module to rotate along the hinge shaft on the first hinge seat 251 under the control of the telescopic mechanism 26, thereby facilitating manual direct striking of the mold 23.

[0027] Furthermore, a telescopic mechanism 26 is provided on the lower side of the support base 24. When the molten tin is discharged, the lifting and lowering of the ingot casting module is controlled so that the molten tin discharged along the second discharge pipe 6 can fall directly into the ingot casting groove 231 of the mold 23, preventing the molten tin from splashing. After multiple molds 23 have finished receiving the molten tin, the ingot casting module is controlled to fall by the telescopic mechanism 26, which facilitates the subsequent manual collection of tin metal ingots.

[0028] Furthermore, both the first discharge pipe 3 and the transfer tank 2 are equipped with heating devices. An electric heating wire is wound around the first discharge pipe 3, and a heat preservation heater is provided on the outside of the transfer tank 2 to heat the transfer tank 2.

[0029] Example 2 This embodiment also provides a method for casting tin metal ingots, which is implemented using the tin metal ingot casting apparatus in Embodiment 1; a. Place the crystalline tin into refining pot 1. After the crystalline tin melts in refining pot 1 by heating it to 350-370℃, take a sample to test the antimony content of the tin liquid in refining pot 1. Add aluminum to the tin liquid according to 1.5 times the antimony percentage of the sample, and stir to allow it to react fully. In this step, the eutectic point temperature of aluminum and tin is 228.3℃, and the aluminum content is 0.5%. As the temperature increases, the solubility of aluminum in liquid tin increases. Therefore, under the condition of 350-370℃, aluminum will dissolve in the molten tin. Aluminum reacts with arsenic and antimony in the molten tin to form a high-melting-point compound, which has a lower density than tin and can crystallize out of the molten tin.

[0030] b. After the aluminum has completely melted, control the temperature of the molten tin between 230℃ and 240℃, and take a sample to test whether the antimony content in the molten tin is up to standard. In this step, aluminum and antimony react to form AlSb, which has a melting point of 1081℃ and a density less than tin, allowing it to crystallize out of the molten tin; thus, the antimony content in the molten tin is less than 0.02%.

[0031] c. After antimony removal is completed, heat the tin liquid to above 270-280℃, add an appropriate amount of ammonium chloride and observe the tin liquid gradually change from grayish-white to red, and finally turn into silvery-white to remove the residual aluminum in the tin liquid. Ammonium chloride reacts with aluminum, causing the aluminum to oxidize and form slag. Sawdust is then added to thicken the slag before it is removed. This portion of the slag contains more than 50% tin, so it must be remelted to recover the tin.

[0032] d. Two hours before the aluminum removal from the molten tin is completed, turn on the heating equipment to heat the transfer tank 2 and the first discharge pipe 3, and control the heating temperature at 270-300℃.

[0033] e. After the heating equipment has been heating for 1.5 hours, open the gas outlet valve 10 and the second liquid discharge valve 7 to fill the first liquid discharge pipe 3 and the transfer tank 2 with protective gas. The protective gas is nitrogen. After the air in the first liquid discharge pipe 3 and the transfer tank 2 is discharged, close the second liquid discharge valve 7 and continue to fill with protective gas to ensure that the pressure read by the pressure gauge 11 is greater than 0.1 MPa before the ingot casting operation.

[0034] f. After the molten tin composition meets the requirements of the corresponding brand, control the temperature of the molten tin at discharge to 250-270℃, open the first discharge valve 4, and when the pressure read by the pressure gauge 11 rises to 0.15Mpa and the amount of molten tin in the transfer tank 2 reaches 50% of its volume, open the second discharge valve 7 to start the ingot casting operation. During the operation, the temperature of the molten tin is maintained at 250-270℃ and the system pressure is stabilized between 0.1-0.15Mpa.

[0035] g. When the molten tin level in the refining pot 1 is less than 10cm above the height of the connection between the refining pot 1 and the first discharge pipe 3, close the first discharge valve 4 to complete the casting operation.

[0036] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Therefore, all equivalent changes or modifications made to the structure, features and principles described in the claims of the present invention should be included within the scope of the present invention.

Claims

1. A tin ingot casting apparatus, comprising a refining pot (1) and a transfer drum (2), characterized in that, It also includes a protective gas storage tank (8) and an ingot casting module. The side of the refining pot (1) is connected to a first liquid discharge pipe (3). The first liquid discharge pipe (3) is equipped with a first liquid discharge valve (4). The end of the first liquid discharge pipe (3) away from the refining pot (1) extends into the transfer barrel (2) from the upper end of the transfer barrel (2). The transfer barrel (2) is rotatably mounted on the base (5) at its lower end. The side of the transfer barrel (2) is connected to a second liquid discharge pipe (6). The second liquid discharge pipe (6) is equipped with a second liquid discharge valve (7). The protective gas storage tank (8) is connected to a gas outlet pipe (9) on its side. A gas outlet valve (10) is provided on the gas outlet pipe (9). The end of the gas outlet pipe (9) away from the protective gas storage tank (8) is connected to the first liquid discharge pipe (3). The connection between the gas outlet pipe (9) and the first liquid discharge pipe (3) is located on the side of the first liquid discharge valve (4) away from the refining pot (1). A pressure gauge (11) is also provided on the first liquid discharge pipe (3). The outlet end of the second discharge pipe (6) faces the ingot casting tank (231) of the ingot casting module, and heating devices are provided on both the first discharge pipe (3) and the transfer tank (2).

2. The tin ingot casting apparatus according to claim 1, characterized in that, The connection between the first liquid discharge pipe (3) and the refining pot (1) is located on the lower side of the refining pot (1).

3. The tin ingot casting apparatus according to claim 1, characterized in that, A sealing ring (12) is provided at the connection between the transfer tank (2) and the first discharge pipe (3), and the first discharge pipe (3) extends into the transfer tank (2) through the sealing ring (12).

4. The tin ingot casting apparatus according to claim 1, characterized in that, An electric heating wire is wound around the first discharge pipe (3), and a heat preservation heater is provided on the outside of the transfer tank (2).

5. A tin ingot casting apparatus according to claim 1, characterized in that, The lower end of the transfer barrel (2) is fixed with a rotating shaft (13), which is rotatably mounted on the base (5). The casting device also includes a motor, the output end of which drives the rotating shaft (13) to rotate.

6. A tin ingot casting apparatus according to claim 1, characterized in that, The ingot casting module includes a first module (21), a second module (22), and multiple molds (23). The first module (21) and the second module (22) are both arc-shaped. Multiple first through slots are evenly provided on the first module (21), and multiple second through slots are evenly provided on the second module (22). Each first through slot and the second through slot are vertically aligned. The upper end of the mold (23) extends into the first through slot, and the lower end extends into the second through slot. The second through slot is U-shaped. The lower end of the mold (23) matches the shape of the second through slot. The first module (21) and the second module (22) are fixedly connected.

7. A tin ingot casting apparatus according to claim 1 or 6, characterized in that, The ingot module is provided with a support base (24) on the lower side, and a support rod (25) is fixed on the support base (24). A telescopic mechanism (26) is hinged on the support base (24). The support rod (25) is located at the end of the ingot module and is hinged to the ingot module. The telescopic mechanism (26) is located on the lower side of the ingot module and is hinged to the ingot module.

8. A tin ingot casting apparatus according to claim 7, characterized in that, A telescopic mechanism (26) is provided on the lower side of the support base (24).

9. A casting method based on a tin ingot casting apparatus according to any one of claims 1-8, characterized in that, Includes the following steps: a. Place the crystalline tin into the refining pot (1). After the crystalline tin is heated to 350-370℃ in the refining pot (1) and melted, take a sample to test the antimony content of the tin liquid in the refining pot (1). Add aluminum to the tin liquid according to 1.5 times the antimony percentage of the sample and stir to make it react fully. b. After the aluminum has completely melted, control the temperature of the molten tin between 230℃ and 240℃, and take a sample to test whether the antimony content in the molten tin is up to standard. c. After antimony removal is completed, heat the tin liquid to above 270-280℃, add an appropriate amount of ammonium chloride and observe the tin liquid gradually change from grayish-white to red, and finally turn silvery-white. Stop when the tin liquid is completely removed to remove the residual aluminum in the tin liquid. d. Before the aluminum removal of the molten tin is completed, turn on the heating equipment two hours in advance to heat the transfer tank (2) and the first discharge pipe (3) and control the heating temperature at 270-300℃. e. After the heating equipment has been heating for 1.5 hours, open the gas outlet valve (10) and the second liquid discharge valve (7) to fill the first liquid discharge pipe (3) and the transfer tank (2) with protective gas. After the air in the first liquid discharge pipe (3) and the transfer tank (2) is discharged, close the second liquid discharge valve (7) and continue to fill with protective gas to ensure that the pressure read by the pressure gauge (11) before the ingot casting operation is greater than 0.1 MPa. f. After the tin liquid composition meets the requirements of the corresponding brand number, control the temperature of the tin liquid when it is discharged to 250-270℃, open the first discharge valve (4), and when the pressure read by the pressure gauge (11) rises to 0.15Mpa, open the second discharge valve (7) to start the ingot casting operation. During the operation, the temperature of the tin liquid is maintained at 250-270℃ and the system pressure is stable between 0.1-0.15Mpa. g. When the liquid level of molten tin in the refining pot (1) is less than 10cm higher than the height of the connection between the refining pot (1) and the first discharge pipe (3), close the first discharge valve (4) to complete the casting operation.

10. A method for casting tin metal ingots according to claim 9, characterized in that, The protective gas used is nitrogen.

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