Large-scale equipment and method for producing rare earth alloys

Abstract

The present invention discloses a large-scale equipment and method for producing rare earth alloys, the equipment comprises a vacuum melting chamber, the furnace body of the vacuum melting chamber is provided with a casting device, a belt throwing device, a crushing device and a storage device from top to bottom in sequence; the casting device comprises a melting assembly and a tundish; the tundish adjusts the contact gap with the belt throwing device through a feed regulating device to control the production thickness of the alloy strip; the belt throwing device comprises a quick-setting copper roller and a quick-setting copper roller driving mechanism, the quick-setting copper roller controls the cooling speed of the alloy strip through a cooling device to allow the alloy strip to be cooled quickly; the outside of the vacuum melting chamber is provided with a PLC control system suitable for controlling the overall operation of the equipment. The present invention controls the precipitation amount of α-Fe in the spun alloy strip by controlling the thickness and cooling speed of the generated alloy strip, thereby obtaining relatively high-quality alloy flakes, thereby providing higher-quality materials for subsequent processes.

Description

Technical Field

[0001] The invention relates to the technical field of rare earth material preparation, and in particular to large-scale equipment and a method for producing rare earth alloys. Background Art

[0002] NdFeB permanent magnet materials are widely used in various industries, especially in the electronic information industry. With the miniaturization and intelligence of devices, the application of high-performance NdFeB permanent magnet materials will become more and more extensive. The production process of NdFeB materials mainly includes smelting in a vacuum quick-setting furnace, spinning the strip to make thin sheets, then hydrogen crushing and air flow grinding to make powder, and the forming press presses the powder into a specified shape, and then sintering in a sintering furnace, surface treatment of the sintered NdFeB rough product, and then cutting it into finished products, and finally serving the needs of various industries.

[0003] From the perspective of sintered NdFeB materials, there are coarse α-Fe dendrites in the existing belt-spinning structure. α-Fe dendrites have good plasticity, making it difficult to break the belt-spinning pieces. At the same time, it will also increase the difficulty of subsequent hydrogen crushing, air flow grinding and other powder making processes, prolong the processing time and increase the processing cost. At the same time, too many α-Fe dendrites will not be able to obtain the same degree of uniform Nd2Fe 14 B needs to spend longer sintering time. The presence of agglomerated Nd-rich phases in the spinning strip structure will affect the uniform distribution of the sintered Nd-rich phase. Therefore, the ideal microscopic state in the spinning strip is that there is no α-Fe dendrite and Nd2Fe 14 The B main phase has fine grains and the Nd-rich phase is evenly distributed. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defects of the existing spun strip structure, such as the presence of coarse α-Fe dendrites, which cause great processing difficulty, long processing time, high processing cost and long sintering time, thereby providing a large-scale equipment and method for producing rare earth alloys, controlling the precipitation amount of α-Fe in the spun strip, and obtaining a relatively high-quality alloy material.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] Large-scale equipment for producing rare earth alloys, including a vacuum melting chamber, wherein a casting device, a belt throwing device, a crushing device and a storage device are sequentially arranged in the furnace body of the vacuum melting chamber from top to bottom;

[0007] The casting device comprises a smelting assembly and a tundish; the smelting assembly is suitable for melting the alloy material and flipping and pouring it; the tundish is located below the smelting assembly and is suitable for receiving the molten alloy liquid, and the contact gap between the tundish and the strip-spinning device is adjusted by the feed adjustment device to control the production thickness of the alloy strip;

[0008] The strip throwing device comprises a quick-setting copper roller and a quick-setting copper roller driving mechanism, wherein the quick-setting copper roller controls the cooling speed of the alloy strip through a cooling device so as to rapidly cool the alloy strip;

[0009] The crushing device is suitable for crushing the alloy strip produced by the strip-throwing device;

[0010] The receiving device is suitable for receiving the alloy strip crushed by the crushing device;

[0011] A PLC control system suitable for controlling the overall operation of the equipment is arranged outside the vacuum melting chamber, and the controlled ends of the casting device, belt throwing device, crushing device, storage device, feed adjustment device and cooling device are respectively connected to the output ends of the PLC control system.

[0012] Further optimizing the technical solution, the feed adjustment device includes:

[0013] A horizontal adjustment device, suitable for positioning the tundish and adjusting the horizontal position of the tundish, wherein the controlled end of the horizontal adjustment device is connected to the output end of the PLC control system; the horizontal adjustment device is provided with a first grating ruler suitable for detecting the horizontal position of the tundish, wherein the output end of the first grating ruler is connected to the input end of the PLC control system;

[0014] A height adjustment device is suitable for adjusting the height position of the horizontal adjustment device and the intermediate package, and the controlled end of the height adjustment device is connected to the output end of the PLC control system; the height adjustment device is provided with a second grating ruler suitable for detecting the height position of the intermediate package, and the output end of the second grating ruler is connected to the input end of the PLC control system.

[0015] To further optimize the technical solution, a plurality of laser sensors suitable for detecting whether the intermediate package is in a horizontal state are arranged above the intermediate package, and the output end of the laser sensor is connected to the input end of the PLC control system.

[0016] Further optimizing the technical solution, the cooling device comprises:

[0017] Cooling medium source;

[0018] The cooling plate is arranged above the quick-setting copper roller and is in the shape of an arc plate; a first cooling medium circulation conveying pipeline connected to a cooling medium source is arranged inside the cooling plate.

[0019] To further optimize the technical solution, the cooling device further includes:

[0020] The second cooling medium circulation conveying pipeline is arranged inside the quick-setting copper roller and along the outer wall of the quick-setting copper roller, and is connected to a cooling medium source.

[0021] To further optimize the technical solution, a speed sensor suitable for detecting the rotation speed of the quick-setting copper roller, a thickness sensor suitable for detecting the thickness of the alloy strip at the quick-setting copper roller, and a reflective temperature sensor suitable for detecting the temperature of the alloy strip at the quick-setting copper roller are arranged on the outer side of the quick-setting copper roller, and the output ends of the speed sensor, the thickness sensor and the reflective temperature sensor are respectively connected to the input end of the PLC control system;

[0022] The thickness sensor comprises a first thickness sensor for measuring the surface spacing of the quick-setting copper roller and a second thickness sensor for measuring the spacing of the alloy strips on the quick-setting copper roller. The thickness of the alloy strip is obtained by the distance difference measured by the first thickness sensor and the second thickness sensor.

[0023] To further optimize the technical solution, the storage device includes:

[0024] A cooling material box with a feed port at the top;

[0025] A stirring system is arranged inside the cooling material box and is suitable for stirring the pulverized alloy strip in the cooling material box; the stirring system comprises a rotating shaft, a stirring blade and a driving motor for driving the rotating shaft to rotate, the rotating shaft and the stirring blade are hollow inside, a plurality of through holes are opened on the side of the stirring blade, and the inside of the rotating shaft is connected to the cooling medium source;

[0026] The temperature measuring system is suitable for detecting the temperature inside the cooling material box, and the output end of the temperature measuring system is connected to the input end of the PLC control system.

[0027] To further optimize the technical solution, product cooling chambers are respectively arranged on both sides of the lower part of the vacuum melting chamber, the product cooling chamber and the vacuum melting chamber are blocked by a first automatic sealing door, and the vacuum melting chamber and the outside atmosphere are blocked by a second automatic sealing door.

[0028] To further optimize the technical solution, roller conveyors are provided at the inner bottom end of the vacuum melting chamber and the inner bottom end of the product cooling chamber, and the roller conveyors are suitable for driving the cooling material box to move laterally.

[0029] Further optimizing the technical solution, the smelting assembly includes:

[0030] The crucible is hingedly arranged on the wall of the furnace body in the vacuum melting chamber;

[0031] The medium frequency coil is melted and wound on the crucible in a spiral shape;

[0032] A tilting device, one end of which is connected to the crucible and the other end of which is connected to the furnace body of the vacuum melting chamber, suitable for driving the crucible to flip; the controlled end of the tilting device is connected to the output end of the PLC control system;

[0033] The encoder rotates synchronously with the tilting device and is suitable for detecting the position of the crucible; the output end of the encoder is connected to the input end of the PLC control system.

[0034] To further optimize the technical solution, the crushing device is a three-roller blade crusher.

[0035] A method for producing a rare earth alloy, the method being carried out based on the large-scale equipment for producing a rare earth alloy, comprising the following steps:

[0036] S1. Determine the casting tilting curve to ensure that the flow rate of the alloy liquid poured out of the smelting assembly is constant;

[0037] S2. Operation of the large-scale equipment for producing rare earth alloys;

[0038] The alloy material is melted in the smelting assembly, and the smelting assembly pours the alloy solution into the tundish;

[0039] The alloy liquid flows onto the quick-setting copper roller through the gap between the tundish and the quick-setting copper roller, and forms an alloy belt on the surface of the quick-setting copper roller;

[0040] S3. In step S2, the contact gap, relative height and horizontality of the tundish and the quick-solidifying copper roller are adjusted, and the cooling rate of the alloy strip on the quick-solidifying copper roller is controlled by a cooling device to limit the precipitation ratio of α-Fe in the alloy strip;

[0041] S4. The alloy strip leaves the quick-setting copper roller and enters the crushing device for crushing;

[0042] S5. The crushed alloy strip falls into a storage device for storage.

[0043] To further optimize the technical solution, in step S5, the flow rate and flow velocity of the cooling medium in the storage device are controlled to further cool the alloy strip evenly and slowly.

[0044] The technical solution of the present invention has the following advantages:

[0045] 1. The large-scale equipment for producing rare earth alloys provided by the present invention controls the precipitation amount of α-Fe in the alloy strips produced by the spinning process by controlling the thickness of the generated alloy strips and the cooling rate, thereby obtaining relatively high-quality alloy flakes, thereby providing higher-quality materials for subsequent processes. The processing cost is reduced, the production time is shortened, and the performance of the product raw materials is greatly improved.

[0046] 2. The large-scale equipment for producing rare earth alloys provided by the present invention has a plurality of laser sensors arranged above the tundish. The laser sensors for measuring the level detect the distance between two points in the width direction of the tundish, thereby controlling the servo motor. The servo motor adjusts the guide rail slide to adjust the height of the two ends of the tundish, thereby ensuring the level of the tundish and allowing the alloy product to maintain thickness consistency in the width direction.

[0047] 3. The large-scale equipment for producing rare earth alloys provided by the present invention adopts a method of arranging a cooling plate above the quick-setting copper roller and arranging a second cooling medium circulation conveying pipeline in the quick-setting copper roller. On the basis of cooling by the cooling plate, the quick-setting copper roller can be further cooled, thereby realizing the cooling of the quick-setting copper roller more quickly.

[0048] 4. In the large-scale equipment for producing rare earth alloys provided by the present invention, the interior of the rotating shaft of the stirring system is connected to the cooling medium source, and argon or helium can be introduced into the rotating shaft to form a cooling system. The stirring blades on the rotating shaft stir the crushed alloy strip in the cooling material box while controlling the flow rate and cooling speed of the cooling gas introduced into the stirring blades installed in the cooling material box, thereby achieving further cooling of the alloy strip to obtain a high-performance alloy product.

[0049] 5. The method for producing rare earth alloy provided by the present invention controls the cooling speed of the alloy strip on the quick-setting copper roller by a cooling device to limit the precipitation ratio of α-Fe in the alloy strip. The specific method is: according to the electrical signal given by the reflective temperature sensor, the flow rate of the cooling gas is adjusted to control the cooling speed of the alloy strip on the quick-setting copper roller, the alloy liquid covers the surface of the quick-setting copper roller to form a strip, the reflective temperature sensor is used to detect the temperature of the strip on the surface of the quick-setting copper roller online, the PLC control system receives the electrical signal of the reflective temperature sensor, and controls the flow controller through the PID regulator to adjust the flow of argon gas in the cooling device above the quick-setting copper roller and the flow of water in the quick-setting copper roller, so that the alloy strip is quickly cooled to the required temperature to prevent the precipitation of α-Fe. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0051] Figure 1 It is a schematic diagram of the structure of a large-scale equipment for producing high-performance rare earth alloys according to the present invention;

[0052] Figure 2 It is a partial structural schematic diagram of a large-scale equipment for producing high-performance rare earth alloys according to the present invention;

[0053] Figure 3 It is a schematic cross-sectional view of the tundish structure of a large-scale equipment for producing high-performance rare earth alloys according to the present invention;

[0054] Figure 4 This is a schematic diagram of the structure of the tundish of a large-scale equipment for producing high-performance rare earth alloys according to the present invention;

[0055] Figure 5 It is a schematic diagram of the thickness measurement principle of the large-scale equipment for producing high-performance rare earth alloys of the present invention;

[0056] Figure 6 It is a schematic diagram of the crucible structure of the large-scale equipment for producing high-performance rare earth alloys of the present invention;

[0057] Figure 7 It is a schematic diagram of the cooling material box structure of the large-scale equipment for producing high-performance rare earth alloys of the present invention;

[0058] Figure 8 This is a schematic diagram of the stirring blade structure of the large-scale equipment for producing high-performance rare earth alloys of the present invention;

[0059] Fig. 9 It is a partial structural schematic diagram of a large-scale equipment for producing high-performance rare earth alloys according to the present invention;

[0060] Fig.10 It is a comparison diagram of the NdFeB alloy material obtained by cooling the NdFeB thin sheet thrown out by the quick-solidification copper roller within the temperature range and the NdFeB alloy material obtained by not cooling within the temperature range;

[0061] Fig.11 It is a casting process curve diagram of the large-scale equipment for producing high-performance rare earth alloys of the present invention when actually producing rare earth alloys.

[0062] Reference numerals:

[0063] 101. Crucible; 1011. Melting medium frequency coil; 102. Tilting device; 103. Cooling plate; 104. Quick-setting copper roller; 105. Thickness sensor; 106. Reflective temperature sensor; 107. Crushing device; 108. Laser sensor; 109. Level adjustment device; 110. Height adjustment device; 111. Servo motor; 112. Temperature measurement system; 113. Cooling box; 114. Stirring blade; 115. Roller conveyor; 116. Product cooling chamber; 117. Tundish; 118. Speed ​​sensor; 119. First automatic sealing door; 120. Second automatic sealing door; 121. Gear; 122. Guide rail slide; 123. Precision ball screw; 124. Liquid leakage sensor. DETAILED DESCRIPTION

[0064] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0065] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0066] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0067] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0068] Example 1

[0069] like Figures 1 to 9 A specific implementation of the large-scale equipment for producing high-performance rare earth alloys shown includes a vacuum melting chamber, in which a casting device, a belt throwing device, a crushing device and a storage device are arranged in sequence from top to bottom in the furnace body.

[0070] The casting device includes a smelting assembly and a tundish 117. The smelting assembly is suitable for melting and flipping the alloy material. The tundish 117 is located below the smelting assembly and is suitable for receiving the molten alloy liquid. The tundish 117 adjusts the contact gap between the tundish 117 and the strip-spinning device through the feed adjustment device to control the production thickness of the alloy strip.

[0071] The strip-swinging device includes a quick-setting copper roller 104 and a quick-setting copper roller driving mechanism. The quick-setting copper roller 104 controls the cooling speed of the alloy strip through a cooling device so that the alloy strip is cooled quickly.

[0072] The crushing device is suitable for crushing the alloy strip produced by the strip-throwing device.

[0073] The receiving device is suitable for receiving the alloy strip crushed by the crushing device.

[0074] A PLC control system suitable for controlling the overall operation of the equipment is arranged outside the vacuum melting chamber, and the controlled ends of the casting device, the belt throwing device, the crushing device 107, the storage device, the feed adjustment device and the cooling device are respectively connected to the output ends of the PLC control system.

[0075] The above-mentioned large-scale equipment for producing rare earth alloys controls the precipitation amount of α-Fe in the alloy strips by controlling the thickness and cooling rate of the generated alloy strips, thereby obtaining relatively high-quality alloy flakes, thereby providing better quality materials for subsequent processes. There are great improvements in terms of reduced processing costs, shortened production time, and performance of product raw materials. The equipment has a single furnace output of more than 2 tons, and a monthly output of 200 to 300 tons.

[0076] More specifically, the large-scale equipment for producing rare earth alloys, when controlling the thickness of the alloy strip, directly controls the operation of the feed adjustment device through the PLC control system, and then controls the contact gap between the tundish 117 and the strip-spinning device through the feed adjustment device. When controlling the cooling speed of the alloy strip, the cooling device is directly controlled through the PLC control system, and then the alloy strip is cooled by the cooling device.

[0077] As a specific implementation, this embodiment discloses the specific structure of the feed adjustment device, which includes a horizontal adjustment device 109 and a height adjustment device 110. Among them, the horizontal adjustment device 109 is suitable for positioning the tundish 117 and adjusting the horizontal position of the tundish 117, and the controlled end of the horizontal adjustment device 109 is connected to the output end of the PLC control system. The horizontal adjustment device 109 is provided with a first grating ruler suitable for detecting the horizontal position of the tundish 117, and the output end of the first grating ruler is connected to the input end of the PLC control system. The height adjustment device 110 is suitable for adjusting the height position of the horizontal adjustment device 109 and the tundish 117, and the controlled end of the height adjustment device 110 is connected to the output end of the PLC control system. The height adjustment device 110 is provided with a second grating ruler suitable for detecting the height position of the tundish 117, and the output end of the second grating ruler is connected to the input end of the PLC control system. In this embodiment, the gap between the tundish 117 and the quick-setting copper roller 104 is adjusted by the joint action of the horizontal adjustment device 109 and the height adjustment device 110.

[0078] More specifically, the horizontal adjustment device 109 and the height adjustment device 110 in this embodiment are both composed of a guide rail slide 122, a grating ruler, a precision ball screw 123, a gear 121, and a servo motor.

[0079] The horizontal adjustment device 109 includes a housing of the horizontal adjustment device, a first guide rail slide, a first grating ruler, a first precision ball screw, a first active bevel gear, a first driven bevel gear, and a first servo motor. In the horizontal adjustment device 109, one end of the first precision ball screw is connected to the first driven bevel gear, and the other end is rotatably connected to the housing of the horizontal adjustment device. The first precision ball screw is slidably mounted on the first guide rail slide. The first servo motor drives the first active bevel gear to rotate. When the first active bevel gear rotates, it drives the first driven bevel gear and the first precision ball screw to rotate, and then the first precision ball screw pulls the first guide rail slide and the intermediate package 117 positioned on the first guide rail slide to slide left and right. The first grating ruler is parallel to the precision ball screw and is arranged on one side of the horizontal adjustment device, which is used to accurately measure the horizontal movement distance of the intermediate package and obtain the current intermediate package position information in real time.

[0080] The height adjustment device 110 includes a height adjustment device housing, a second guide rail slide, a second grating ruler, a second precision ball screw, a second active bevel gear, a second driven bevel gear, and a second servo motor. In the height adjustment device 110, one end of the second precision ball screw is connected to the second driven bevel gear and the other end is connected to the second guide rail slide. The second servo motor drives the second active bevel gear to rotate. When the second active bevel gear rotates, it drives the second driven bevel gear and the second precision ball screw to rotate, and then the second precision ball screw pulls the second guide rail slide and the tundish 117 located on the second guide rail slide to be lifted or lowered. The second grating ruler is parallel to the precision ball screw and is arranged on one side of the height adjustment device, which is used to accurately measure the lifting and lowering distance of the tundish and obtain the current tundish position information in real time.

[0081] The structure of the horizontal adjustment device is the same as that of the height adjustment device, except that the shell of the horizontal adjustment device is installed directly above the second guide rail slide of the height adjustment device. When the guide rail slide of the height adjustment device moves upward, the horizontal adjustment device can be lifted as a whole; the horizontal and height adjustment devices cooperate to adjust the horizontal and height positions of the intermediate package.

[0082] As a further improved implementation, a plurality of laser sensors 108 are arranged above the tundish 117 to detect whether the tundish is in a horizontal state. The laser sensors 108 are non-contact laser sensors, and the output end of the laser sensor 108 is connected to the input end of the PLC control system. The laser sensor 108 for measuring the level detects the distance between two points in the width direction of the tundish, thereby controlling the servo motor, and the servo motor adjusts the guide slide to adjust the height of the two ends of the tundish, thereby ensuring the level of the tundish, so that the alloy product can maintain the consistency of thickness in the width direction. The automated measurement and control system is integrated on the rolling line to monitor the levelness. High-precision measurement is necessary to control these devices. This measurement can realize non-contact laser online measurement. Since the bandwidth of the OPTIMESS sensor is as high as 10KHZ, high-precision shape measurement can even be performed online at high speed. Three OPTIMESS sensors are used at the hot end to measure the levelness (edge-middle-edge), and the laser sensor transmits the detection electrical signal to the PLC system and the general computer Fourier software is used for analysis and calculation to control the servo motor.

[0083] The cross-section of the tundish is rectangular and hollow inside, but one side is left empty in the width direction. A mullite rib is set on the side without a baffle, and mullite plates are laid on the inner surface and the bottom of the inner surface. There is a certain gap between the mullite rib and the inner bottom surface, and the alloy liquid flows out from the gap and then flows into the quick-setting copper roller.

[0084] As a specific implementation, the cooling device includes a cooling medium source and a cooling plate 103. The cooling plate 103 is arranged above the quick-setting copper roller 104 and is in the shape of an arc plate. A first cooling medium circulation delivery pipeline connected to the cooling medium source is arranged inside the cooling plate 103. In this embodiment, the cooling medium is delivered to the cooling plate through the first cooling medium circulation delivery pipeline, so that the cooling plate cools down the quick-setting copper roller 104 below it.

[0085] The cooling medium source is water, argon or helium, which are not limited here.

[0086] As a further improved implementation, the cooling device further includes a second cooling medium circulation delivery pipeline, which is arranged inside the quick-setting copper roller 104 and along the outer wall of the quick-setting copper roller 104, and is connected to a cooling medium source. In this embodiment, the cooling medium is introduced into the second cooling medium circulation delivery pipeline, and the quick-setting copper roller 104 can be further cooled on the basis of cooling by the cooling plate, thereby realizing faster cooling of the quick-setting copper roller 104.

[0087] As a further improved implementation, a speed sensor 118, a thickness sensor 105 and a reflective temperature sensor 106 are arranged on the outer side of the quick-setting copper roller 104. The speed sensor 118 is suitable for detecting the speed of the quick-setting copper roller, the thickness sensor 105 is suitable for detecting the thickness of the alloy strip at the quick-setting copper roller, and the reflective temperature sensor 106 is suitable for detecting the temperature of the alloy strip at the quick-setting copper roller. The output ends of the speed sensor 118, the thickness sensor 105 and the reflective temperature sensor 106 are respectively connected to the input end of the PLC control system.

[0088] The thickness measuring sensor 105 is a non-contact thickness measuring laser sensor, and the reflective temperature measuring sensor 106 is a non-contact temperature measuring sensor, both of which are at a certain distance from the quick-setting copper roller 104 .

[0089] The thickness sensor 105 includes a first thickness sensor and a second thickness sensor. The first thickness sensor is suitable for measuring the surface distance of the quick-setting copper roller 104. The second thickness sensor is suitable for measuring the distance between the alloy strips on the quick-setting copper roller 104. The thickness of the alloy strip is obtained by the distance difference measured by the first thickness sensor and the second thickness sensor.

[0090] As a further improved implementation method, the quick-setting copper roller 104 is steplessly adjusted between 10 and 60 rpm by a frequency converter, and the controlled end of the frequency converter is connected to the output end of the PLC control system, so that this embodiment can adjust the rotation speed of the quick-setting copper roller 104.

[0091] As a specific implementation method, this embodiment discloses the specific structure of the smelting component, which includes a crucible 101, a smelting intermediate frequency coil 1011, a tilting device 102 and an encoder. The crucible 101 is hingedly arranged on the inner wall of the furnace body of the vacuum smelting chamber, and the tundish 117 is placed below the crucible 101. The smelting intermediate frequency coil 1011 is spirally wound on the crucible. One end of the tilting device 102 is connected to the crucible, and the other end is connected to the furnace body of the vacuum smelting chamber, which is suitable for driving the crucible to flip, and the controlled end of the tilting device 102 is connected to the output end of the PLC control system. The encoder rotates synchronously with the tilting device 102, which is suitable for detecting the position of the crucible 101, and the output end of the encoder is connected to the input end of the PLC control system. The encoder adopts an absolute rotary encoder.

[0092] More specifically, the tilting device 102 is preferably a lifting cylinder, two of which are symmetrically installed on both sides of the crucible, and a hydraulic servo valve is provided on the oil pipeline of the lifting cylinder, and the controlled end of the hydraulic servo valve is connected to the output end of the PLC control system. When the piston rod of the lifting cylinder is retracted, the crucible 101 can be driven to flip, thereby realizing the dumping of the alloy liquid.

[0093] As a specific implementation, this embodiment discloses the specific structure of the crushing device 107, which is a three-roller blade crusher. The three-roller blade crusher includes three single rollers, a chain drive assembly, and a knife roller drive motor. The center of the single roller is a long cylindrical shape, and long and short thin metal plates are alternately arranged on the outer surface. The three single rollers are arranged in parallel along the length direction. A more specific arrangement is: a single roller is arranged on the top, and two single rollers are arranged symmetrically with respect to the center of the upper single roller on the bottom.

[0094] As a specific implementation method, this embodiment discloses the specific structure of a storage device, which includes a cooling material box 113, a stirring system, and a temperature measuring system 112. A feed port is provided at the top of the cooling material box 113, and is in the shape of a rectangular box. The stirring system is arranged inside the cooling material box 113, and is suitable for stirring the crushed alloy strip in the cooling material box. The stirring system includes a rotating shaft, a stirring blade and a driving motor. The stirring blade is welded on the rotating shaft by spirally winding a metal plate. Both ends of the rotating shaft are installed on both sides of the cooling material box, and the stirring blades on the rotating shaft are close to the bottom of the cooling box. The driving motor is connected to one end of the rotating shaft to provide a driving motor for rotational power.

[0095] As a further improved implementation method, in order to obtain high-performance alloy products, the alloy sheets must be further evenly and slowly cooled in the cooling box 113. Therefore, the interior of the rotating shaft and the stirring blades in this embodiment are hollow, and a number of through holes are opened on the sides of the stirring blades. The interior of the rotating shaft is connected to the cooling medium source, and argon or helium can be introduced into the rotating shaft to form a cooling system. The stirring blades on the rotating shaft stir the crushed alloy strips in the cooling box 113 while controlling the cooling gas flow rate and cooling speed of the stirring blades installed in the cooling box to achieve further cooling of the alloy strips.

[0096] As a further improved implementation, a temperature measuring system 112 is further provided inside the storage device, the temperature measuring detection head end of the temperature measuring system 112 is provided inside the cooling material box 113, and the signal transmission end of the temperature measuring system 112 is located outside the cooling material box 113. The temperature measuring system 112 is suitable for detecting the temperature inside the cooling material box, the output end of the temperature measuring system 112 is connected to the input end of the PLC control system, and the temperature measuring system 112 uses a temperature measuring sensor.

[0097] As a further improved implementation, product cooling chambers 116 are respectively provided on both sides of the lower part of the vacuum melting chamber, and the product cooling chamber 116 is blocked from the vacuum melting chamber by a first automatic sealing door, and the vacuum melting chamber is blocked from the outside atmosphere by a second automatic sealing door. More specifically, the product cooling chamber is divided into a first product cooling chamber and a second product cooling chamber, and the two product cooling chambers are symmetrical with the crusher as the center. The right side of the first product cooling chamber is separated from the vacuum melting chamber, and the left side of the second product cooling chamber is separated from the vacuum melting chamber by a first automatic sealing door 119, and the left side of the first product cooling chamber and the right side of the second product cooling chamber are separated from the outside atmosphere by a second automatic sealing door 120.

[0098] As a further improved implementation, a roller conveyor 115 is provided at the inner bottom of the vacuum melting chamber and the inner bottom of the product cooling chamber, and the roller conveyor 115 is suitable for driving the cooling material box to move horizontally. The roller conveyor 115 includes a supporting wheel and a supporting wheel driving motor for driving the supporting wheel to rotate. Then, after the cooling material box 113 receives the crushed alloy strip, it moves under the drive of the roller conveyor 115. When the first automatic sealing door 119 is opened, the cooling material box 113 can enter the first product cooling chamber or the second product cooling chamber for further cooling.

[0099] As a further improved implementation, a liquid storage tank is also provided at the inner bottom of the product cooling chamber, and a liquid leakage sensor 124 is provided at the bottom of the liquid storage tank. The liquid leakage sensor 124 is used to detect whether there is liquid leakage in the product cooling chamber. The output end of the liquid leakage sensor 124 is connected to the input end of the PLC control system.

[0100] Example 2

[0101] A method for producing a rare earth alloy, which is based on the large-scale equipment for producing a rare earth alloy in Example 1, comprises the following steps:

[0102] S1. Determine the relationship between time and the crucible tilting angle, that is, determine the casting tilting curve to ensure that the flow rate of the alloy liquid poured out of the smelting assembly is constant.

[0103] S2. Operate the large-scale equipment for producing rare earth alloys in Example 1.

[0104] S21. The alloy material is melted in the smelting assembly, and the smelting assembly pours the alloy solution into the tundish 117.

[0105] The specific steps of step S21 are:

[0106] The tilting of the crucible is controlled by an absolute rotary encoder, proximity switch, PID regulator, PLC control system, etc. The absolute rotary encoder feeds back the position information of the crucible to the PLC control system in real time. After the steel ingot is melted in the crucible, the PLC control system controls the rotation of the quick-setting copper roller and the operation of other auxiliary equipment, including the cooling water of the cooling plate, the introduction of cooling gas Ar / Hc, the operation of the crusher, the initialization of various sensors including reflective temperature sensors and speed sensors, and then starts the PID regulator. The PID regulator gives the corresponding voltage to control the hydraulic servo valve according to the set tilting curve, and the hydraulic device drives the lifting cylinder to tilt the crucible containing the molten steel. At the same time, the encoder rotating together with the tilting device also collects the corresponding pulse signal, which is converted by the PLC for comparison by the PID regulator, so as to accurately control the tilting process and pour the alloy liquid into the tundish evenly and constantly. The inclination angle of the tundish is adjusted between 0 and 1°. The end in contact with the quick-setting copper roller is low and protruding with a molten liquid outflow nozzle, which can make the molten liquid pour into the tundish along the protruding position.

[0107] S22. The laser sensor 108 for measuring the level detects the distance between two points in the width direction, thereby controlling the servo motor, which adjusts the guide rail slide to adjust the height of the two ends of the tundish, thereby ensuring the level of the tundish and allowing the rare earth alloy product to maintain consistency in thickness in the width direction.

[0108] S23. The alloy liquid flows onto the quick-solidifying copper roller 104 through the gap between the tundish 117 and the quick-solidifying copper roller 104, and forms an alloy belt on the surface of the quick-solidifying copper roller 104.

[0109] S3. In step S2, the contact gap, relative height and horizontality of the tundish and the quick-setting copper roller are adjusted.

[0110] The tundish is in contact with the rotating quick-setting copper roller 104, covering the surface of the quick-setting copper roller 104 with a width of about 800mm to form a strip. The thickness of the strip is detected online by the non-contact laser sensor 108 and the speed sensor 118, thereby controlling the servo motor 111. The servo motor adjusts the guide slide, adjusts the height of the tundish and the contact gap between the tundish and the quick-setting copper roller between 0 and 10mm, and controls the speed of the quick-setting copper roller to obtain the required alloy strip thickness between 0.25mm and 0.35mm. Arranging two thickness sensors is the basis for thickness measurement, such as Figure 4As shown. First, the first thickness sensor measures the surface of the quick-setting copper roller, and a designated origin for the quick-setting copper roller is used as the zero point. The product moves on the quick-setting copper roller, and another thickness sensor is arranged to measure a thickness value relative to the zero point. The distance difference measured by the two sensors gives the thickness value of the product. The argon-cooled OPTIMESS sensor can measure high-temperature materials. The laser sensor transmits the detection electrical signal to the PLC and the general computer Fourier software performs analysis and calculation to control the servo motor.

[0111] The adjustment method for the thickness of alloy strip is as follows: manually calibrate the minimum distance between the tundish and the cooling copper roller, defined as Po. At this time, P1=P2=Po, that is, P1-P2=△P=0. Secondly, set the strip thickness H on the operation screen, and the CPU calculates the distance P between the tundish and the cooling copper roller. The P value is given. The built-in PID soft module of the servo controller calculates the position deviation, outputs a drive signal, drives the servo motor to drive the tundish to move horizontally or vertically, and the grating ruler detects the displacement. After reaching the position, the controller sends a stop signal, and the thickness sensor detects the strip thickness. The CPU compares the difference between the set thickness and the actual thickness △H=H-H1. When △H is less than the set tolerance range a, △Px=0, and there is no need to correct the position given signal P. When △H is greater than the set tolerance range a, △Px=na+b, correct the position given signal P, and drive the servo motor to move.

[0112] The cooling speed of the alloy strip on the quick-solidifying copper roller 104 is controlled by a cooling device to limit the precipitation ratio of α-Fe in the alloy strip.

[0113] The cooling gas flow rate is adjusted according to the electrical signal given by the reflective temperature sensor to control the cooling speed of the rare earth alloy strip on the quick-setting copper roller. The alloy liquid covers the surface of the quick-setting copper roller with a width of about 800 mm to form a strip. The reflective temperature sensor 106 detects the temperature of the strip on the surface of the quick-setting copper roller online. The PLC control system receives the electrical signal of the reflective temperature sensor 106, controls the flow controller through the PID regulator, adjusts the flow of argon gas in the cooling device above the quick-setting copper roller and the flow of water in the quick-setting copper roller, so that the alloy strip is quickly cooled to the required temperature to prevent the precipitation of α-Fe, such as Figure 2 shown.

[0114] The temperature required for cooling the alloy strip is set to T1, and the reflective temperature sensor 106 detects the temperature of the alloy strip to be T2. The PLC control system calculates the difference △T=T1-T2, and the PID regulator outputs a control signal according to its deviation, and controls the size of the cooling gas flow through the flow controller. When the requirement is met, the flow controller sends a stop signal. The reflective temperature sensor 106 detects the temperature of the alloy strip, and the PLC compares the difference between the set temperature and the actual temperature. When △T>0, the cooling gas flow is increased through the flow controller; when △T<0, the cooling gas flow is reduced through the flow controller.

[0115] S4. The alloy strip leaves the quick-setting copper roller 104 and enters the crushing device for crushing.

[0116] The alloy strip cooled to the required temperature leaves the surface of the rotating quick-setting copper roller and enters the three-roller blade crusher to be broken into alloy flakes the size of a fingernail, so as to facilitate further uniform and slow cooling of the alloy flakes in the cooling material box 113.

[0117] S5. The crushed alloy strip falls into a storage device for storage.

[0118] The stirring blade device installed in the cooling box controls the cooling gas flow rate and cooling rate. In order to obtain high-performance alloy products, the alloy sheet must be further evenly and slowly cooled in the cooling box 113. For this purpose, a stirring blade 114 is installed in the cooling box 113. Argon or helium is introduced into the stirring blade 114. Argon or helium is ejected from the stirring blade to make full contact with the alloy sheet. The temperature of the alloy sheet is detected by the temperature measuring system 112, and then the PLC control system receives the electrical signal of the reflective temperature sensor to control the flow controller, adjust the flow rate of argon or helium, and control the cooling rate of the alloy sheet to make the alloy sheet evenly and slowly cooled, thereby obtaining a high-performance alloy product.

[0119] Taking NdFeB alloy material as an example, the temperature of NdFeB steel liquid is 1400℃-1500℃. After the quick-setting copper roller casts and throws the sheet, the temperature of the sheet is still very high, between 800℃-950℃. According to the analysis of the NdFeB crystal phase diagram and a large number of production experiments, the sheet between 800℃-950℃ is cooled for 2 hours to 3 hours, and finally the product temperature is cooled to 50℃, which can make the neodymium-rich phase generated in the sheet more uniform, optimize the coercive force of the product, and obtain high-performance NdFeB alloy material (such as Fig.10 As shown in the figure on the right); Compared with products that are not treated in this range, if the cooling time is too fast or too long, it will affect the formation of the final metallographic structure of the product, and it is also very easy to produce neodymium-rich phase agglomeration (such as Fig.10 left).

[0120] S6. The storage device is moved to the product cooling chamber for cooling, and then the product cooling chamber is opened to take out the alloy sheets in the storage device.

[0121] like Fig.11As shown in the figure, this is a casting process curve diagram for rare earth alloy production. In the figure, the temperature of the steel liquid at the beginning of pouring is 1400℃, the time of the quick-setting copper roller to throw off the sheet is very short, and it only takes 0.5s to complete. The temperature after the sheet is thrown off is 900℃. After the sheet is thrown off, it enters the cooling and recrystallization stage. When the temperature of the product drops to 50℃, the cooling process of the product is completed. The product is then kept warm and cooled again. The subsequent keeping warm and cooling operations on the product will no longer affect the performance of the product.

[0122] Obviously, the above embodiments are merely examples for clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from them are still within the protection scope of the invention.

Claims

1. A large-scale apparatus for producing rare earth alloys, comprising a vacuum melting chamber, characterized in that: The furnace body of the vacuum smelting chamber is provided with a casting device, a belt throwing device, a crushing device and a storage device in sequence from top to bottom; The casting device comprises a smelting assembly and a tundish (117); the smelting assembly is suitable for melting alloy materials and overturning and pouring them; the tundish (117) is located below the smelting assembly and is suitable for receiving molten alloy liquid, and the contact gap between the tundish (117) and the strip-spinning device is adjusted by a feed adjustment device to control the production thickness of the alloy strip; The strip-swinging device comprises a quick-setting copper roller (104) and a quick-setting copper roller driving mechanism, wherein the quick-setting copper roller (104) controls the cooling speed of the alloy strip through a cooling device so as to rapidly cool the alloy strip; The cooling device comprises a cooling medium source and a cooling plate (103); the cooling plate (103) is arranged above the quick-setting copper roller (104) and is in the shape of an arc plate; a first cooling medium circulation conveying pipeline connected to the cooling medium source is arranged inside the cooling plate; The crushing device is suitable for crushing the alloy strip produced by the strip-throwing device; The receiving device is suitable for receiving the alloy strip crushed by the crushing device; A PLC control system suitable for controlling the overall operation of the equipment is arranged outside the vacuum melting chamber, and the controlled ends of the casting device, the belt throwing device, the crushing device, the storage device, the feed regulating device and the cooling device are respectively connected to the output ends of the PLC control system; The outer side of the quick-setting copper roller (104) is provided with a thickness sensor (105) suitable for detecting the thickness of the alloy strip at the quick-setting copper roller and a reflective temperature sensor (106) suitable for detecting the temperature of the alloy strip at the quick-setting copper roller. The output ends of the thickness sensor (105) and the reflective temperature sensor (106) are respectively connected to the input end of the PLC control system. The thickness sensor detects the strip thickness and feeds back the actual thickness information to the PLC controller. The PLC controller controls the feed adjustment device based on the difference between the set thickness and the actual thickness. The reflective temperature sensor (106) detects the temperature of the strip on the surface of the quick-setting copper roller online. The PLC control system receives the electrical signal of the reflective temperature sensor (106), controls the flow controller through the PID regulator, and adjusts the flow of the medium of the cooling device above the quick-setting copper roller, so that the alloy strip is quickly cooled to a required temperature.

2. The large-scale equipment for producing rare earth alloys according to claim 1, characterized in that: The feed adjustment device comprises: A horizontal adjustment device (109) is adapted to position the tundish (117) and adjust the horizontal position of the tundish (117), wherein a controlled end of the horizontal adjustment device (109) is connected to an output end of a PLC control system; a first grating ruler adapted to detect the horizontal position of the tundish (117) is provided on the horizontal adjustment device (109), wherein an output end of the first grating ruler is connected to an input end of the PLC control system; The height adjustment device (110) is suitable for adjusting the height position of the horizontal adjustment device (109) and the intermediate package (117), and the controlled end of the height adjustment device (110) is connected to the output end of the PLC control system; the height adjustment device (110) is provided with a second grating ruler suitable for detecting the height position of the intermediate package (117), and the output end of the second grating ruler is connected to the input end of the PLC control system.

3. The large-scale equipment for producing rare earth alloys according to claim 2, characterized in that: A plurality of laser sensors (108) suitable for detecting whether the tundish is in a horizontal state are arranged above the tundish (117), and output ends of the laser sensors (108) are connected to input ends of a PLC control system.

4. The large-scale equipment for producing rare earth alloys according to claim 1, characterized in that: The cooling device also includes: A second cooling medium circulation delivery pipeline is arranged inside the quick-setting copper roller (104) and along the outer wall of the quick-setting copper roller (104), and is connected to a cooling medium source.

5. The large-scale equipment for producing rare earth alloys according to any one of claims 1 to 4, characterized in that: A speed sensor (118) suitable for detecting the rotation speed of the quick-setting copper roller is arranged on the outer side of the quick-setting copper roller (104), and an output end of the speed sensor (118) is connected to an input end of a PLC control system; The thickness sensor (105) comprises a first thickness sensor suitable for measuring the surface spacing of the quick-setting copper roller (104) and a second thickness sensor suitable for measuring the spacing of the alloy strips on the quick-setting copper roller (104). The thickness of the alloy strip is obtained by the distance difference measured by the first thickness sensor and the second thickness sensor.

6. The large-scale equipment for producing rare earth alloys according to claim 1, characterized in that: The storage device comprises: A cooling material box (113) having a material feed port at the top; A stirring system is arranged inside the cooling material box and is suitable for stirring the pulverized alloy strip in the cooling material box; the stirring system comprises a rotating shaft, a stirring blade and a driving motor for driving the rotating shaft to rotate, the rotating shaft and the stirring blade are hollow inside, a plurality of through holes are opened on the side of the stirring blade, and the inside of the rotating shaft is connected to the cooling medium source; The temperature measurement system (112) is suitable for detecting the temperature inside the cooling material box, and the output end of the temperature measurement system (112) is connected to the input end of the PLC control system.

7. The large-scale equipment for producing rare earth alloys according to claim 6, characterized in that: Product cooling chambers (116) are respectively arranged on both sides of the lower part of the vacuum melting chamber; the product cooling chamber (116) and the vacuum melting chamber are blocked by a first automatic sealing door, and the vacuum melting chamber and the outside atmosphere are blocked by a second automatic sealing door.

8. The large-scale equipment for producing rare earth alloys according to claim 7, characterized in that: A roller conveyor (115) is provided at the inner bottom end of the vacuum smelting chamber and the inner bottom end of the product cooling chamber. The roller conveyor (115) is suitable for driving the cooling material box to move laterally.

9. The large-scale equipment for producing rare earth alloys according to claim 1, characterized in that: The smelting assembly comprises: The crucible (101) is hingedly arranged on the inner wall of the furnace body of the vacuum melting chamber; A smelting medium frequency coil (1011) is spirally wound on the crucible; A tilting device (102), one end of which is connected to the crucible and the other end of which is connected to the furnace body of the vacuum melting chamber, suitable for driving the crucible to flip; the controlled end of the tilting device (102) is connected to the output end of the PLC control system; An encoder rotates synchronously with the tilting device (102) and is suitable for detecting the position of the crucible (101); an output end of the encoder is connected to an input end of a PLC control system.

10. The large-scale equipment for producing rare earth alloys according to claim 1, characterized in that: The crushing device is a three-roller blade crusher.

11. A method for producing a rare earth alloy, characterized in that: The method is carried out based on the large-scale equipment for producing rare earth alloys according to any one of claims 1 to 10, and comprises the following steps: S1. Determine the casting tilting curve to ensure that the flow rate of the alloy liquid poured out of the smelting assembly is constant; S2. Operation of a large-scale device for producing rare earth alloys as described in any one of claims 1 to 10; The alloy material is melted in the melting assembly, and the melting assembly pours the alloy solution into a tundish (117); The alloy liquid flows onto the quick-setting copper roller (104) through the gap between the tundish (117) and the quick-setting copper roller (104), and forms an alloy strip on the surface of the quick-setting copper roller (104); S3. In step S2, the contact gap and relative height between the tundish (117) and the quick-setting copper roller (104) and the horizontality of the tundish (117) are adjusted, and the cooling rate of the alloy strip on the quick-setting copper roller (104) is controlled by a cooling device to limit the precipitation ratio of α-Fe in the alloy strip; S4. The alloy strip leaves the quick-setting copper roller (104) and enters a crushing device for crushing; S5. The crushed alloy strip falls into a storage device for storage.

12. The method for producing a rare earth alloy according to claim 11, characterized in that: In the step S5, the flow rate and flow velocity of the cooling medium in the storage device are controlled to further cool the alloy strip evenly and slowly.

Images