Vertical vacuum spiral crystallization apparatus and method for continuous separation of binary eutectic alloys

Abstract

The present invention relates to a vertical vacuum spiral crystallization apparatus and method for continuously separating binary eutectic alloys, which belongs to the technical field of non-ferrous metal pyrometallurgy. The vertical vacuum spiral crystallization apparatus for continuously separating binary eutectic alloys includes a vertical furnace body, a feeding system, a heating system, a water circulation cooling system, a rotating system, a vacuum system, a discharging system, and an observation system. The object of the apparatus and method is binary eutectic alloys with eutectic point arbitrary composition, so the operation of the apparatus is simple, the strength is low, there is no "three wastes" in the treatment process, the direct recovery rate of metals is maximized, the working environment is good, and the process is safe and controllable.

Description

[Technical field]

[0001] The present invention relates to a vertical vacuum spiral crystallization apparatus and method for continuously separating binary eutectic alloys, which belongs to the technical field of non-ferrous metal pyrometallurgy. [Background technology]

[0002] The fractional crystallization method realizes the separation of impurities by utilizing the difference in the solubility of impurities in the main metal in the solid state and the main metal in the liquid state. It belongs to intermetallic phase separation, and has the advantages of energy saving, low-temperature operation, and separation of high-purity products. The electric heating continuous crystallization apparatus, invented in China in the 1970s based on the fractional crystallization method, is one of the most important equipment in the tin smelting process, and its main function is to realize the removal of lead from crude tin. However, the traditional electric heating continuous crystallization apparatus has a low degree of automation, high water consumption, and poor working environment for workers. For decades, Chinese scientists and engineers have been changing it. Patent Document 1 discloses an electric heating spiral crystallization apparatus, mainly providing an electric heating spiral crystallization apparatus with a suitable temperature ratio of each heating section, high productivity of a single machine, and low water consumption in the manufacturing process. Patent Document 2 discloses an electric heating spiral crystallization apparatus for crude tin processing, aiming at improving the use of electric heating in the soldering process to reduce the pollution caused by diesel combustion to the environment and improve the comfort of the working environment for workers. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] China patent disclosure 205662564U [Patent Document 2] China Patent Disclosure 206069975U Summary of the Invention [Problem to be solved by the invention]

[0004] In view of the problems and deficiencies of the prior art mentioned above, the present invention provides a vertical vacuum spiral crystallization apparatus and method for continuously separating binary eutectic alloys. The apparatus and method of the present invention process binary alloys containing any component with a eutectic point, and the apparatus is simple to operate, has low strength, does not generate "three wastes" during the processing process, maximizes the direct recovery rate of metals, has a good operating environment, and is a safe and controllable process. The present invention is realized by the following technical solutions: [Means for solving the problem]

[0005] A vertical vacuum spiral crystallization apparatus for continuously separating a binary eutectic alloy, comprising a vertical furnace body, a supply system, a heating system, a water circulation cooling system, a rotation system, a vacuum system, a discharge system, and an observation system; The supply system includes a crucible 2, a supply pipe 3, and a supply switch 4, the rotation system includes a rotary blade 9, a rotary shaft 10, and a motor 14, the vacuum system includes a vacuum pump 15 and a series of valves, the discharge system includes a discharge pipe I11, a discharge switch I12, a baffle 17, a discharge pipe II18, a discharge switch II19, a melt pot 13, and a crystal pot 20, The working temperature of the crucible 2 of the supply system is 300-1000°C. Inside the crucible 2, an inlet end of a supply pipe 3 is provided which is immersed in the melt of the raw material 1. The outlet end of the supply pipe 3 is sealed and communicated with the top of the vertical furnace body by a supply switch 4. A motor 14 is provided at the top of the vertical furnace body. The motor 14 is connected to a rotating shaft 10 which is sealed and inserted into the inner cylinder 8 of the vertical furnace body. A rotating blade 9 is arranged on the rotating shaft 10. A vacuum pump 15 is provided at the top of the vertical furnace body to evacuate the vertical furnace body to a vacuum degree of 1-100 Pa. A crystal melting area with an inclination angle of 3°-7° (length 30-50 cm, width 15-200 mm) is provided at a point where the distance between the top of the vertical furnace body and the inside of the inner cylinder 8 is 1-2 mm. 100 cm), a baffle 17 is installed in the crystal melting area so as to be offset from the center, a heating system and a water circulation cooling system are installed on the outer wall of the inner cylinder 8, a heating system with a temperature range of 350 to 800°C is installed at the bottom of the crystal melting area, the crystal melting area is connected to the discharge area, a discharge pipe II18 and a discharge switch II19 are installed at the bottom of the discharge area, a crystal pot 20 is installed at the bottom of the discharge pipe II18, a heating system is installed in the discharge area, a discharge pipe I11 is installed at the bottom of the inner cylinder 8, and the discharge pipe I11 is connected to the melt pot 13 at the bottom via the discharge switch I12, and an observation port 16 of an observation system is installed at the top of the vertical furnace body.

[0006] The throughput of the vertical vacuum spiral crystallizer is 100-500 kg / day.

[0007] The heating system includes a heating element 5 and a thermal insulation layer 6, where the heating element 5 is a resistance wire and the thermal insulation layer 6 is an alumina refractory brick.

[0008] The water circulation cooling system includes a water circulation device and a water circulation pipe 7 .

[0009] The inner cylinder 8 has a controllable heating region in which the temperature gradient gradually decreases from top to bottom by the heating system and water circulation cooling system of each stage, with the top being a high-temperature segment and the bottom being a low-temperature segment, with the temperature of the high-temperature segment being 200-800°C and the temperature of the low-temperature segment being 100-650°C.

[0010] The rotation speed of the motor 14 is 0 to 50 rpm, the diameter of the inner cylinder 8 is 15 to 100 cm, the height is 2 to 5 m, and the distance between the outer edge of the rotary blade 9 and the inner cylinder 8 is 5 to 20 mm.

[0011] The vacuum pump 15 is a direct-coupled two-stage rotary vane vacuum pump, and has an exhaust speed of 15 to 25 L / s.

[0012] This is a vertical vacuum spiral crystallization method for continuously separating binary eutectic alloys, and its specific steps include the steps of continuously injecting binary eutectic alloy raw material from crucible 2 into inner cylinder 8 through a siphon in a vacuum state, there being a temperature gradient in inner cylinder 8, and as motor 14 rotates, crystals are continuously precipitated and transported to the top of inner cylinder 8, flowing into the crystal melting region, the crystals pass through a baffle to be melted again, and are discharged from discharge switch II, while periodically turning on discharge switch I to release the melt.

[0013] The binary eutectic alloy raw material includes a tin-lead alloy, a tin-bismuth alloy, a lead-bismuth alloy, or a tin-aluminum alloy. Effect of the Invention

[0014] The beneficial effects of the present invention are: The processing object of this device and method is binary eutectic alloys containing any eutectic point composition, so the raw material is highly universal, the device is easy to operate, the strength is low, there is no "three wastes" in the processing process, the direct recovery rate of metals is maximized, the working environment is good, and the process is safe and controllable. Compared with the conventional diagonal horizontal arrangement of the crystallizer tank, this device uses a vertical arrangement, which further utilizes gravity to accelerate the backflow of the melt and improve the purity of the crystal. At the same time, this device adds a vacuum system, which on the one hand avoids the problem of metal oxidation and improves the direct recovery rate of metal, and on the other hand reduces heat loss under the vacuum system, improving energy efficiency. [Brief description of the drawings]

[0015] [Figure 1] Schematic diagram of the structure of the device of the present invention; [Diagram 2] Baffle of the present invention DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Example 1 As shown in Figures 1 and 2, the vertical vacuum spiral crystallization apparatus for continuously separating the binary eutectic alloy includes a vertical furnace body, a supply system, a heating system, a water circulation cooling system, a rotation system, a vacuum system, a discharge system, and an observation system. The supply system includes a crucible 2, a supply pipe 3 and a supply switch 4, the rotation system includes a rotary blade 9, a rotary shaft 10 and a motor 14, the vacuum system includes a vacuum pump 15 and a series of valves, the discharge system includes a discharge pipe I11, a discharge switch I12, a baffle 17, a discharge pipe II18, a discharge switch II19, a melt pot 13 and a crystal pot 20, The working temperature of the crucible 2 of the supply system is 300-1000°C. Inside the crucible 2, an inlet end of a supply pipe 3 is provided which is immersed in the melt of the raw material 1. The outlet end of the supply pipe 3 is connected to the top of the vertical furnace by a supply switch 4. A motor 14 is provided at the top of the vertical furnace. The motor 14 is connected to a rotating shaft 10 which is hermetically inserted into the inner cylinder 8 of the vertical furnace. A rotating blade 9 is disposed on the rotating shaft 10. A vacuum pump 15 is provided at the top of the vertical furnace to evacuate the vertical furnace to a vacuum degree of 1-100 Pa. A crystal melting area with an inclination angle of 3° (length 30 cm, width 15 cm) is provided at a point where the distance between the top of the vertical furnace and the inside of the inner cylinder 8 is 1-2 mm. ), the crystal melting area is provided with baffles 17 arranged so as to be offset from one another, a heating system and a water circulation cooling system are installed on the outer wall of the inner cylinder 8, a heating system with a temperature range of 350 to 800°C is installed at the bottom of the crystal melting area, the crystal melting area is connected to the discharge area, a discharge pipe II18 and a discharge switch II19 are installed at the bottom of the discharge area, a crystal pot 20 is installed at the bottom of the discharge pipe II18, a heating system is installed in the discharge area, a discharge pipe I11 is installed at the bottom of the inner cylinder 8, and the discharge pipe I11 is connected to the melt pot 13 at the bottom via the discharge switch I12, and an observation port 16 of an observation system is installed at the top of the vertical furnace body.

[0017] Here, the throughput of the vertical vacuum spiral crystallizer is 100-500 kg / day, the heating system includes a heating element 5 and a heat insulating layer 6, the heating element 5 is a resistance wire, the heat insulating layer 6 is an alumina refractory brick, the water circulation cooling system includes a water circulation device and a water circulation pipe 7, the inner cylinder 8 is formed by the heating system and the water circulation cooling system of each stage, a controllable heating area with a gradually decreasing temperature gradient from top to bottom, the top is a high temperature segment, the bottom is a low temperature segment, the temperature of the high temperature segment is 200-800°C, and the temperature of the low temperature segment is 100-650°C, The rotation speed of the motor 14 is 0 to 50 rpm, the diameter of the inner cylinder 8 is 15 cm, the height is 2 m, and the distance between the outer edge of the rotary blade 9 and the inner cylinder 8 is 5 mm.

[0018] The vacuum pump 15 is a direct-coupled two-stage rotary vane vacuum pump, and has an exhaust speed of 15 to 25 L / s.

[0019] The vertical vacuum spiral crystallization method for continuously separating the binary eutectic alloy includes the following specific steps: (1) 100 kg of a tin-lead binary alloy (composition: Sn 90%, Pb 10%) is melted in a crucible 2 at a working temperature of 500°C, the supply switch 4, the discharge switch I 12, and the discharge switch II 19 are turned off, the vacuum pump 15 is started, the pressure in the vertical furnace is made less than 100 Pa, the top temperature of the inner cylinder 8 is made 232°C, the bottom temperature is made 183°C, and the heating system is started. (2) After the temperature gradient of the vertical furnace body is stabilized, turn on the supply pipe switch 4 and simultaneously start the motor 14 to operate at a speed of 3 rpm; (3) The state of the crystals was confirmed through the observation port 16, the temperature of the crystal melting area was set to 350°C, and the discharge switch was turned on at irregular intervals to release the molten material and crystals, ultimately resulting in solder with a lead content of 38.4% and a refined tin product with a tin content of 99.6%.

[0020] In this embodiment, a vertical vacuum spiral crystallizer was used to continuously separate the binary eutectic alloy, and compared to conventional electrothermal crystallizers, the direct recovery rate of metallic tin was increased by 5% and the energy efficiency was increased by 8%.

[0021] Example 2 As shown in Figures 1 and 2, the vertical vacuum spiral crystallization apparatus for continuously separating the binary eutectic alloy includes a vertical furnace body, a supply system, a heating system, a water circulation cooling system, a rotation system, a vacuum system, a discharge system, and an observation system. The supply system includes a crucible 2, a supply pipe 3 and a supply switch 4, the rotation system includes a rotary blade 9, a rotary shaft 10 and a motor 14, the vacuum system includes a vacuum pump 15 and a series of valves, the discharge system includes a discharge pipe I11, a discharge switch I12, a baffle 17, a discharge pipe II18, a discharge switch II19, a melt pot 13 and a crystal pot 20, The working temperature of the crucible 2 of the supply system is 300-1000°C. Inside the crucible 2, an inlet end of a supply pipe 3 is provided, which is immersed in the melt of the raw material 1. The outlet end of the supply pipe 3 is sealed and communicated with the top of the vertical furnace by a supply switch 4. A motor 14 is provided at the top of the vertical furnace, and the motor 14 is connected to a rotating shaft 10 that is sealed and inserted into the inner cylinder 8 of the vertical furnace. A rotating blade 9 is arranged on the rotating shaft 10. A vacuum pump 15 is provided at the top of the vertical furnace to evacuate the vertical furnace to a vacuum degree of 1-100 Pa. A crystal melting area with an inclination angle of 7° (length 50 cm, width 100 cm) is provided at a point where the distance between the top of the vertical furnace and the inside of the inner cylinder 8 is 1-2 mm. m), in the crystal melting area, a baffle 17 is installed so as to be offset, a heating system and a water circulation cooling system are installed on the outer wall of the inner cylinder 8, a heating system with a temperature range of 350 to 800 ° C is installed at the bottom of the crystal melting area, the crystal melting area is connected to the discharge area, a discharge pipe II 18 and a discharge switch II 19 are installed at the bottom of the discharge area, a crystal pot 20 is installed at the bottom of the discharge pipe II 18, a heating system is installed in the discharge area, a discharge pipe I 11 is installed at the bottom of the inner cylinder 8, and the discharge pipe I 11 is connected to the melt pot 13 at the bottom via the discharge switch I 12, and an observation port 16 of an observation system is installed at the top of the vertical furnace body.

[0022] Here, the throughput of the vertical vacuum spiral crystallizer is 100-500 kg / day, the heating system includes a heating element 5 and a heat insulating layer 6, the heating element 5 is a resistance wire, the heat insulating layer 6 is an alumina refractory brick, the water circulation cooling system includes a water circulation device and a water circulation pipe 7, the inner cylinder 8 is formed by the heating system and the water circulation cooling system of each stage, a controllable heating area with a gradually decreasing temperature gradient from top to bottom, the top is a high temperature segment, the bottom is a low temperature segment, the temperature of the high temperature segment is 200-800°C, and the temperature of the low temperature segment is 100-650°C, The rotation speed of the motor 14 is 0 to 50 rpm, the diameter of the inner cylinder 8 is 100 cm, the height is 5 m, and the distance between the outer edge of the rotary blade 9 and the inner cylinder 8 is 20 mm.

[0023] The vacuum pump 15 is a direct-coupled two-stage rotary vane vacuum pump, and has an exhaust speed of 15 to 25 L / s.

[0024] The vertical vacuum spiral crystallization method for continuously separating the binary eutectic alloy includes the following specific steps: (1) 500 kg of a tin-lead binary alloy (composition: Sn 95%, Pb 5%) is melted in a crucible 2 at an operating temperature of 300°C, the supply switch 4, the discharge switch I 12, and the discharge switch II 19 are turned off, the vacuum pump 15 is started, the pressure in the vertical furnace is set to less than 100 Pa, and the top temperature of the inner cylinder 8 is set to 232°C, the bottom temperature is set to 183°C, and the heating system is started. (2) After the temperature gradient of the vertical furnace body is stabilized, turn on the supply pipe switch 4 and simultaneously start the motor 14 to operate at a speed of 2 rpm; (3) The state of the crystals was confirmed through the observation port 16, the temperature of the crystal melting area was set to 350°C, and the discharge switch was turned on at irregular intervals to release the molten material and crystals, ultimately resulting in solder with a lead content of 37.8% and a refined tin product with a tin content of 99.9%. In this embodiment, a vertical vacuum spiral crystallizer was used to continuously separate the binary eutectic alloy, and compared to conventional electrothermal crystallizers, the direct recovery rate of metallic tin was increased by 4% and the energy efficiency was increased by 15%.

[0025] Example 3 As shown in Figures 1 and 2, the vertical vacuum spiral crystallization apparatus for continuously separating the binary eutectic alloy includes a vertical furnace body, a supply system, a heating system, a water circulation cooling system, a rotation system, a vacuum system, a discharge system, and an observation system. The supply system includes a crucible 2, a supply pipe 3 and a supply switch 4, the rotation system includes a rotary blade 9, a rotary shaft 10 and a motor 14, the vacuum system includes a vacuum pump 15 and a series of valves, the discharge system includes a discharge pipe I11, a discharge switch I12, a baffle 17, a discharge pipe II18, a discharge switch II19, a melt pot 13 and a crystal pot 20, The working temperature of the crucible 2 of the supply system is 300-1000°C. Inside the crucible 2, an inlet end of a supply pipe 3 is provided which is immersed in the melt of the raw material 1. The outlet end of the supply pipe 3 is connected to the top of the vertical furnace by a supply switch 4. A motor 14 is provided at the top of the vertical furnace. The motor 14 is connected to a rotating shaft 10 which is hermetically inserted into the inner cylinder 8 of the vertical furnace. A rotating blade 9 is disposed on the rotating shaft 10. A vacuum pump 15 is provided at the top of the vertical furnace to evacuate the vertical furnace to a vacuum degree of 1-100 Pa. A crystal melting area with an inclination angle of 6° (length 40 cm, width 80 cm) is provided at a point where the distance between the top of the vertical furnace and the inside of the inner cylinder 8 is 1-2 mm. ), the crystal melting area is provided with baffles 17 arranged so as to be offset from one another, a heating system and a water circulation cooling system are installed on the outer wall of the inner cylinder 8, a heating system with a temperature range of 350 to 800°C is installed at the bottom of the crystal melting area, the crystal melting area is connected to the discharge area, a discharge pipe II18 and a discharge switch II19 are installed at the bottom of the discharge area, a crystal pot 20 is installed at the bottom of the discharge pipe II18, a heating system is installed in the discharge area, a discharge pipe I11 is installed at the bottom of the inner cylinder 8, and the discharge pipe I11 is connected to the melt pot 13 at the bottom via the discharge switch I12, and an observation port 16 of an observation system is installed at the top of the vertical furnace body.

[0026] Here, the throughput of the vertical vacuum spiral crystallizer is 100-500 kg / day, the heating system includes a heating element 5 and a heat insulating layer 6, the heating element 5 is a resistance wire, the heat insulating layer 6 is an alumina refractory brick, the water circulation cooling system includes a water circulation device and a water circulation pipe 7, the inner cylinder 8 is formed by the heating system and the water circulation cooling system of each stage, from top to bottom, a controllable heating area with a gradually decreasing temperature gradient is formed, the top is a high temperature segment, the bottom is a low temperature segment, the temperature of the high temperature segment is 200-800°C, and the temperature of the low temperature segment is 100-650°C; The rotation speed of the motor 14 is 0 to 50 rpm, the diameter of the inner cylinder 8 is 80 cm, the height is 4 m, and the distance between the outer edge of the rotary blade 9 and the inner cylinder 8 is 15 mm.

[0027] The vacuum pump is a direct-coupled two-stage rotary vane vacuum pump with a pumping speed of 15 to 25 L / s.

[0028] The vertical vacuum spiral crystallization method for continuously separating the binary eutectic alloy includes the following specific steps: (1) 500 kg of tin-aluminum binary alloy (composition: Sn 20%, Al 80%) is melted in the crucible 2 at a working temperature of 1000°C, the supply switch 4, the discharge switch I 12, and the discharge switch II 19 are turned off, the vacuum pump 15 is started, the pressure in the vertical furnace is made less than 100 Pa, and the top temperature of the inner cylinder 8 is made 232°C, the bottom temperature is made 183°C, and the heating system is started. (2) After the temperature gradient of the vertical furnace body is stabilized, turn on the supply pipe switch 4 and simultaneously start the motor 14 to operate at a speed of 2 rpm; (3) The state of the crystals was confirmed through the observation port 16, the temperature of the crystal melting area was set to 800°C, and the discharge switch was turned on at irregular intervals to release the molten material and crystals, resulting in crude tin containing 85% tin and crude aluminum containing 99% aluminum.

[0029] In this example, a vertical vacuum spiral crystallizer was used to continuously separate the binary eutectic alloy, and the direct recovery rate of metallic aluminum was increased by 21% and the energy efficiency was increased by 27% compared to the electrolysis method.

[0030] Example 4 As shown in Figures 1 and 2, the vertical vacuum spiral crystallization apparatus for continuously separating the binary eutectic alloy includes a vertical furnace body, a supply system, a heating system, a water circulation cooling system, a rotation system, a vacuum system, a discharge system, and an observation system. The supply system includes a crucible 2, a supply pipe 3 and a supply switch 4, the rotation system includes a rotary blade 9, a rotary shaft 10 and a motor 14, the vacuum system includes a vacuum pump 15 and a series of valves, the discharge system includes a discharge pipe I11, a discharge switch I12, a baffle 17, a discharge pipe II18, a discharge switch II19, a melt pot 13 and a crystal pot 20, The working temperature of the crucible 2 of the supply system is 300-1000°C. Inside the crucible 2, an inlet end of a supply pipe 3 is provided which is immersed in the melt of the raw material 1. The outlet end of the supply pipe 3 is connected to the top of the vertical furnace by a supply switch 4. A motor 14 is provided at the top of the vertical furnace. The motor 14 is connected to a rotating shaft 10 which is hermetically inserted into the inner cylinder 8 of the vertical furnace. A rotating blade 9 is disposed on the rotating shaft 10. A vacuum pump 15 is provided at the top of the vertical furnace to evacuate the vertical furnace to a vacuum degree of 1-100 Pa. A crystal melting area with an inclination angle of 6° (length 45 cm, width 85 cm) is provided at a point where the distance between the top of the vertical furnace and the inside of the inner cylinder 8 is 1-2 mm. ), the crystal melting area is provided with baffles 17 arranged so as to be offset from one another, a heating system and a water circulation cooling system are installed on the outer wall of the inner cylinder 8, a heating system with a temperature range of 350 to 800°C is installed at the bottom of the crystal melting area, the crystal melting area is connected to the discharge area, a discharge pipe II18 and a discharge switch II19 are installed at the bottom of the discharge area, a crystal pot 20 is installed at the bottom of the discharge pipe II18, a heating system is installed in the discharge area, a discharge pipe I11 is installed at the bottom of the inner cylinder 8, and the discharge pipe I11 is connected to the melt pot 13 at the bottom via the discharge switch I12, and an observation port 16 of an observation system is installed at the top of the vertical furnace body.

[0031] Here, the throughput of the vertical vacuum spiral crystallizer is 100-500 kg / day, the heating system includes a heating element 5 and a heat insulating layer 6, the heating element 5 is a resistance wire, the heat insulating layer 6 is an alumina refractory brick, the water circulation cooling system includes a water circulation device and a water circulation pipe 7, the inner cylinder 8 is formed by the heating system and the water circulation cooling system of each stage, a controllable heating area with a gradually decreasing temperature gradient from top to bottom, the top is a high temperature segment, the bottom is a low temperature segment, the temperature of the high temperature segment is 200-800°C, and the temperature of the low temperature segment is 100-650°C, The rotation speed of the motor 14 is 0 to 50 rpm, the diameter of the inner cylinder 8 is 65 cm, the height is 4 m, and the distance between the outer edge of the rotary blade 9 and the inner cylinder 8 is 18 mm.

[0032] The vacuum pump 15 is a direct-coupled two-stage rotary vane vacuum pump, and has an exhaust speed of 15 to 25 L / s.

[0033] The vertical vacuum spiral crystallization method for continuously separating the binary eutectic alloy includes the following specific steps: (1) 200 kg of tin-bismuth binary alloy (composition: Pb62.5%, Bi37.5%) is melted in the crucible 2 at a working temperature of 400°C, the supply switch 4, the discharge switch I12, and the discharge switch II19 are turned off, the vacuum pump 15 is started, the pressure in the vertical furnace is made less than 100 Pa, the top temperature of the inner cylinder 8 is made 232°C, the bottom temperature is made 183°C, and the heating system is started. (2) After the temperature gradient of the vertical furnace body is stabilized, turn on the supply pipe switch 4 and simultaneously start the motor 14 to operate at a speed of 2 rpm; (3) The state of the crystals was confirmed through the observation port 16, the temperature of the crystal melting area was set to 400°C, and the discharge switch was turned on at irregular intervals to release the molten material and crystals, resulting in crude bismuth containing 77% bismuth and crude lead containing 98.7% lead.

[0034] In this example, a vertical vacuum spiral crystallizer was used to continuously separate the binary eutectic alloy, and the direct recovery rate of metallic lead increased by 18% and the energy efficiency increased by 22% compared to the electrolysis method.

[0035] Although specific embodiments of the present invention have been described in detail above with reference to the drawings, the present invention is not limited to the above embodiments. [Explanation of symbols]

[0036] 1-raw material, 2-crucible, 3-feed pipe, 4-feed switch, 5-heating element, 6-insulation layer, 7-water circulation pipe, 8-inner cylinder, 9-rotating blade, 11-discharge pipe I, 12-discharge switch I, 13-melt pot, 14-motor, 15-vacuum pump, 16-observation port, 17-baffle, 18-discharge pipe II, 19-discharge switch II, 20-crystal pot

Claims

1. A vertical vacuum spiral crystallization apparatus for continuously separating a binary eutectic alloy, comprising a vertical furnace body, a supply system, a heating system, a water circulation cooling system, a rotation system, a vacuum system, a discharge system and an observation system; The vertical furnace body is equipped with an inner tube (8) and a branch pipe connected to the top of the inner tube (8) and extending downward toward a crystal pot (20). A crystal melting zone is disposed at the bottom of the top of the branch pipe, where the crystals precipitated in the inner tube (8) are heated and melted. The supply system includes a crucible (2), a supply pipe (3) and a supply switch (4), the rotation system includes a rotary blade (9), a rotary shaft (10) and a motor (14), the vacuum system includes a vacuum pump (15) and a series of valves, and the discharge system includes a discharge pipe I (11), a discharge switch I (12), a baffle (17), a discharge pipe II (18), a discharge switch II (19), a melt pot (13) and the crystal pot (20). The working temperature of the crucible (2) of the supply system is 300-1000° C., an inlet end of a supply pipe (3) immersed in the melt of the raw material (1) is provided inside the crucible (2), an outlet end of the supply pipe (3) is sealed and connected to the top of a vertical furnace by a supply switch (4), the motor (14) is provided at the top of the vertical furnace, and the motor (14) is driven by the rotating shaft (14) inserted into the inner cylinder (8) of the vertical furnace in a sealed manner. The vertical furnace body is connected to a rotating shaft (10), the rotating blades (9) are arranged on the rotating shaft (10), a vacuum pump (15) is provided at the top of the vertical furnace body for evacuating the vertical furnace body to a vacuum degree of 1 to 100 Pa, the crystal melting area has a downward inclination angle of 3° to 7°, the crystal melting area has a length of 30 to 50 cm and a width of 15 to 100 cm, plate-shaped baffles (17) are installed in a staggered arrangement in the crystal melting area, and the front A heating system and a water circulation cooling system are installed on the outer wall of the inner cylinder (8), a heating system with a temperature range of 350 to 800°C is installed at the bottom of the crystal melting zone, a discharge zone is connected to the crystal melting zone, the discharge pipe II (18) and the discharge switch II (19) are installed at the bottom of the discharge zone, the crystal pot (20) is installed at the bottom of the discharge pipe II (18), a heating system is installed in the discharge zone, the discharge pipe I (11) is installed at the bottom of the inner cylinder (8), the discharge pipe I (11) is connected to the melt pot (13) at the bottom via the discharge switch I (12), an observation port (16) of an observation system is installed at the top of the vertical furnace body, and the rotating system transfers the contents of the inner cylinder (8) from bottom to top by rotating a spiral rotating blade (9) according to the rotation of the rotating shaft (10) by the motor (14), The inner cylinder (8) is formed with a controllable heating zone with a gradually decreasing temperature gradient from top to bottom by the heating system and water circulation cooling system of each stage, the top is a high temperature segment, the bottom is a low temperature segment, the temperature of the high temperature segment is 200-800°C, the temperature of the low temperature segment is 100-650°C. A vertical vacuum spiral crystallizer for continuously separating binary eutectic alloys.

2. 2. The vertical vacuum spiral crystallizer for continuously separating binary eutectic alloys according to claim 1, wherein the throughput of said vertical vacuum spiral crystallizer is 100-500 kg / day.

3. The vertical vacuum spiral crystallizer for continuous separation of binary eutectic alloys according to claim 1, characterized in that the heating system includes a heating element (5) and a heat insulating layer (6), the heating element (5) being a resistance wire, and the heat insulating layer (6) being an alumina refractory brick.

4. The vertical vacuum spiral crystallizer for continuously separating binary eutectic alloys as claimed in claim 1, characterized in that the water circulation cooling system includes a water circulation device and a water circulation pipe (7).

5. The vertical vacuum spiral crystallization apparatus for continuously separating binary eutectic alloys according to claim 1, characterized in that the rotation speed of the motor (14) is 0-50 rpm, the diameter of the inner cylinder (8) is 15-100 cm, the height is 2-5 m, and the distance between the outer edge of the rotating blade (9) and the inner cylinder (8) is 5-20 mm.

6. The vertical vacuum spiral crystallization apparatus for continuously separating binary eutectic alloys according to claim 1, characterized in that the vacuum pump (15) is a direct-coupled two-stage rotary vane vacuum pump, and the pumping speed is 15 to 25 L / s.

7. A vertical vacuum spiral crystallization method for continuously separating binary eutectic alloys, the specific steps of which include the steps of: continuously injecting binary eutectic alloy raw material from a crucible (2) into an inner cylinder (8) through a siphon in a vacuum state; there is a temperature gradient in the inner cylinder (8); as the motor (14) rotates, crystals are continuously precipitated, transported to the top of the inner cylinder (8), flow into a crystal melting region and melt again; and discharged from a discharge pipe II (18) through a discharge switch II; and at the same time, periodically turning on a discharge switch I at the bottom of the inner cylinder (8) to discharge the melt from a discharge pipe I (11). According to the rotation of the rotating shaft (10) by the motor (14), the contents of the inner cylinder (8) are transferred from bottom to top by the rotation of the spiral rotating blade (9), The inner cylinder (8) is formed with a controllable heating zone with a gradually decreasing temperature gradient from top to bottom by the heating system and water circulation cooling system of each stage, the top is a high temperature segment, the bottom is a low temperature segment, the temperature of the high temperature segment is 200-800°C, the temperature of the low temperature segment is 100-650°C; A branch pipe is provided at the top of the inner cylinder (8), which is connected to the inner cylinder (8) and faces downward toward the discharge pipe II (18). A crystal melting region is provided at the bottom of the top of the branch pipe, which is a region where the crystals precipitated in the inner cylinder (8) are heated and melted. In the crystal melting area, plate-shaped baffles (17) are arranged in a staggered pattern. A vertical vacuum spiral crystallization method for continuously separating binary eutectic alloys, comprising:

8. The vertical vacuum spiral crystallization method for continuously separating binary eutectic alloys according to claim 7, characterized in that the binary eutectic alloy raw material comprises a tin-lead alloy, a tin-bismuth alloy, a lead-bismuth alloy or a tin-aluminum alloy.

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