A roasting furnace for separating and recovering tantalum and niobium from tin residue and a method thereof

Abstract

The present application provides a kind of from tin dross separation and recovery roasting furnace of tantalum niobium and method thereof.The from tin dross separation and recovery roasting furnace of tantalum niobium includes: base;Furnace body, the furnace body is installed on the base, the top of the furnace body is equipped with burner, the furnace body is used to input tin dross powder to realize roasting;Stirring assembly, the stirring assembly is installed in the furnace body, the stirring assembly is used for mixing stirring when tin dross powder roasting, recess is opened in the furnace body inner wall.The present application provides the roasting furnace of from tin dross separation and recovery tantalum niobium and method thereof, by the first stirring structure longitudinal rotation to material mixing, cooperate the second stirring structure transverse rotation to provide transverse shear force, avoid the single stirring face to form stirring dead angle, improve the uniformity of material mixing, and also can turn over material when roasting, make roasting fully carry out, to improve the tantalum niobium recovery efficiency.

Description

Technical Field

[0001] This invention relates to the field of metal recycling, and more particularly to a roasting furnace and method for separating and recovering tantalum and niobium from tin slag. Background Technology

[0002] Tin slag is a major solid waste generated during tin smelting. It often contains a certain amount of valuable metals such as tantalum and niobium. The tantalum and niobium oxide content in some tin slag can reach the recycling standard, making it a valuable secondary resource of tantalum and niobium. If tantalum and niobium in tin slag are not separated and recycled, it will not only waste valuable strategic resources, but also cause serious environmental problems due to the long-term occupation of land by tin slag, seepage and pollution of soil and groundwater. Achieving efficient separation and recycling of tantalum and niobium in tin slag can improve the comprehensive utilization efficiency of resources, promote the green disposal of metallurgical waste, conform to the concept of circular economy development, and have significant economic, environmental and social benefits.

[0003] Currently, the main processes for separating and recovering tantalum and niobium from tin slag fall into three categories: pyrometallurgical processes, hydrometallurgical processes, and combined pyrometallurgical and hydrometallurgical processes. Among them, the pyrometallurgical process, with roasting as its core, uses high-temperature roasting to cause a phase transformation of the tantalum and niobium minerals in the tin slag, breaking their bond with gangue minerals and creating conditions for subsequent leaching, separation, and purification. Due to its advantages such as high processing efficiency, strong adaptability, and ease of industrial scale-up, it has become one of the mainstream process routes for tantalum and niobium recovery from tin slag.

[0004] Currently, most existing roasting furnaces used for tantalum and niobium recovery from tin slag are traditional box-type, tunnel-type, or rotary-type structures. The tin slag material is unevenly distributed in the furnace and does not have sufficient contact with the roasting medium, resulting in uneven distribution of the heated area of ​​the material. This leads to problems such as local overheating or incomplete roasting, resulting in incomplete phase transformation of tantalum and niobium minerals in the tin slag. Consequently, the dissolution rate of tantalum and niobium during the subsequent leaching process is low, making it difficult to achieve efficient recovery of tantalum and niobium.

[0005] Therefore, it is necessary to provide a calcining furnace and method for separating and recovering tantalum and niobium from tin slag to solve the above-mentioned technical problems. Summary of the Invention

[0006] This invention provides a calcining furnace and method for separating and recovering tantalum and niobium from tin dross, which solves the problems of uneven distribution of tin dross material in the furnace and insufficient contact with the calcining medium, resulting in uneven distribution of the heated area of ​​the material and local overheating or incomplete calcination.

[0007] To solve the above-mentioned technical problems, the present invention provides a calcining furnace for separating and recovering tantalum and niobium from tin dross, comprising: a base;

[0008] A furnace body is mounted on the base, and a burner is installed on the top of the furnace body. The furnace body is used to feed tin dross powder for roasting.

[0009] A stirring assembly is installed inside the furnace body. The stirring assembly is used for mixing and stirring tin slag powder during roasting. A groove is provided on the inner wall of the furnace body. The stirring assembly includes a first stirring structure and a second stirring structure. The first stirring structure is installed on the furnace body, and the second stirring structure is installed in the groove. During stirring, both the first stirring structure and the second stirring structure rotate.

[0010] A feeding assembly is installed inside the furnace body and is used for feeding tin dross powder;

[0011] A discharge assembly is installed at the bottom of the furnace body and is used to discharge the roasted product.

[0012] A drive assembly, which is mounted on the furnace body, is used to drive the stirring assembly to rotate;

[0013] A flue gas exhaust pipe is installed on the furnace body, and a filter element is installed inside the flue gas exhaust pipe;

[0014] A cleaning assembly is installed inside the furnace body and is used for cleaning the filter element.

[0015] Preferably, the first stirring structure includes a rotating shaft, a first stirring blade, a first bevel gear, and an eccentric wheel. The rotating shaft is rotatably connected to the furnace body, one end of the rotating shaft passes through the furnace body and extends to the outside of the furnace body, the first stirring blade is fixed to the outer surface of the rotating shaft, the first bevel gear is fixed to one end of the rotating shaft, and the eccentric wheel is fixed to the outer surface of the rotating shaft.

[0016] Preferably, the second stirring structure includes a sealing ring, a toothed ring, a scraper, and a second stirring blade. The sealing ring is rotatably connected to the groove, the toothed ring is fixed to the outer surface of the sealing ring, the scraper is fixed to the inner surface of the sealing ring, and the second stirring blade is fixed to the scraper.

[0017] Preferably, the feeding assembly includes a heat exchange box, a mounting plate, a first feed pipe, a second feed pipe, and a heat exchange coil. The heat exchange box is fixed to the top of the furnace body, the mounting plate is installed on the right side of the heat exchange box, the first feed pipe is installed on the top of the heat exchange box, the second feed pipe is installed on the bottom of the heat exchange box and communicates with the furnace body, and the heat exchange coil is installed on the mounting plate.

[0018] Preferably, the right side of the heat exchange box is open, the mounting plate is detachably connected to the right side of the heat exchange box, and one end of the heat exchange coil is detachably connected to one end of the flue gas exhaust pipe via a connector.

[0019] Preferably, the discharge assembly includes a discharge trough, a pusher, an inclined plate, a sealing plate, and a protrusion. The discharge trough is installed at the bottom of the furnace body, the pusher is fixed on the discharge trough, the inclined plate is installed at the output end of the pusher, the sealing plate is fixed on the inclined plate, and the protrusion is installed at the bottom of the discharge trough.

[0020] Preferably, the driving assembly includes a driving component, a first sleeve rod, a sliding rod, a second bevel gear, a fixing block, a second sleeve rod, a gear, and a roller. The driving component is fixed to the furnace body, the first sleeve rod is fixed to the output shaft of the driving component, the sliding rod is slidably connected inside the first sleeve rod, the second bevel gear is fixed to the outer surface of the sliding rod, the fixing block is fixed to the furnace body, the second sleeve rod is rotatably connected to the fixing block, the second sleeve rod is slidably connected to the sliding rod, the gear is fixed to the outer surface of the second sleeve rod, and the roller is installed at the bottom end of the sliding rod.

[0021] Preferably, the cleaning assembly includes a fixed frame, a sliding block, a fixed plate, an elastic element, a connecting rod, and a cleaning component. The fixed frame is fixed to the side wall of the furnace body, the sliding block is slidably connected within the fixed frame, the fixed plate is fixed to the bottom of the sliding block, the fixed plate passes through the fixed frame and extends to the bottom of the fixed frame, the elastic element is disposed between the sliding block and the fixed frame, the connecting rod is fixed to the top of the sliding block, the connecting rod passes through the fixed frame and extends to the top of the fixed frame, and the cleaning component is fixed to the top of the connecting rod.

[0022] The present invention also provides a method for separating and recovering tantalum and niobium from tin dross, comprising the aforementioned calcining furnace for separating and recovering tantalum and niobium from tin dross and the following steps:

[0023] S1. Dry, crush, and sieve the tin dross to obtain tin dross powder;

[0024] S2. Add tin dross powder, potassium bisulfate, and sulfuric acid into the furnace body, mix them in a certain proportion, and then perform roasting treatment to obtain the roasted product.

[0025] S3. The roasted product is mixed with oxalic acid solution in a certain proportion and leached, filtered to obtain leachate and residue; the residue contains ZrO2 and CaO, and is washed with ultrapure water to remove residual oxalic acid and metal ions, which can be further extracted as zirconium or used as building material raw material.

[0026] S4. Adjust the pH of the leachate, filter it, and obtain filtrate one.

[0027] S5. Add filtrate one to sodium carbonate solution to remove calcium ions and obtain filtrate two.

[0028] S6. Mix the extractant methyl isobutyl ketone with filtrate 2, shake and separate to obtain an organic phase containing tantalum and niobium;

[0029] S7. The tantalum-niobium-containing organic phase is back-extracted with pure water and sulfuric acid solution respectively to obtain tantalum-containing back-extraction solution and niobium-containing back-extraction solution;

[0030] S8. Add ammonia to the back-extraction solution, stir, and filter to obtain tantalum hydroxide and niobium hydroxide;

[0031] S9. Tantalum hydroxide and niobium hydroxide are calcined to obtain tantalum pentoxide and niobium pentoxide.

[0032] Compared with related technologies, the calcining furnace and method for separating and recovering tantalum and niobium from tin dross provided by the present invention have the following beneficial effects:

[0033] This invention provides a roasting furnace and method for separating and recovering tantalum and niobium from tin slag. The invention utilizes a first stirring structure that rotates longitudinally to mix materials, while a second stirring structure rotates laterally to provide lateral shear force. This avoids dead zones formed by a single stirring surface, improving the uniformity of material mixing. Furthermore, the material can be turned over during roasting, ensuring thorough roasting and thus improving tantalum and niobium recovery efficiency. The rotation of the first stirring structure is linked to the reciprocating motion of a cleaning component to clean the filter, preventing clogging and reducing manual maintenance costs. The extension of the pushing component opens the discharge chute for material discharge. During discharge, the rotation of the driving component, in conjunction with the rotation of the second stirring structure, causes the scraper to scrape material from the bottom of the furnace inner wall, preventing material from adhering to the inner wall and forming rings, while also preventing material accumulation at the outlet and blockage during discharge. Attached Figure Description

[0034] Figure 1 A schematic diagram of a preferred embodiment of the calcining furnace and method for separating and recovering tantalum and niobium from tin slag provided by the present invention;

[0035] Figure 2 for Figure 1 The diagram shows a cross-sectional view of the furnace body.

[0036] Figure 3 for Figure 2 The enlarged schematic diagram of part A shown below;

[0037] Figure 4 for Figure 3 The diagram shows the structure of the stirring assembly.

[0038] Figure 5 for Figure 2A cross-sectional schematic diagram of the feeding assembly shown;

[0039] Figure 6 for Figure 2 The diagram shows the structure of the discharge assembly.

[0040] Figure 7 for Figure 2 The diagram shows the structure of the driving component.

[0041] Figure 8 for Figure 2 The diagram shows the structure of the cleaning component.

[0042] Figure 9 This is a schematic diagram of the initial state of the present invention;

[0043] Figure 10 This is a schematic diagram of the present invention in the discharge state.

[0044] Numbering on the map:

[0045] 1. Base; 2. Furnace body; 3. Burner;

[0046] 4. Stirring assembly; 41. First stirring structure; 42. Second stirring structure; 411. Rotating shaft; 412. First stirring blade; 413. First bevel gear; 414. Eccentric wheel; 421. Sealing ring; 422. Gear ring; 423. Scraper; 424. Second stirring blade.

[0047] 5. Groove;

[0048] 6. Feeding assembly; 61. Heat exchanger box; 62. Mounting plate; 63. First feed pipe; 64. Second feed pipe; 65. Heat exchanger coil;

[0049] 7. Discharge assembly; 71. Discharge chute; 72. Pushing component; 73. Inclined plate; 74. Sealing plate; 75. Protrusion.

[0050] 8. Drive assembly; 81. Drive component; 82. First sleeve rod; 83. Sliding rod; 84. Second bevel gear; 85. Fixed block; 86. Second sleeve rod; 87. Gear; 88. Roller;

[0051] 9. Flue gas exhaust pipe; 10. Filter element;

[0052] 11. Cleaning component; 111. Fixing frame; 112. Sliding block; 113. Fixing plate; 114. Elastic element; 115. Connecting rod; 116. Cleaning component. Detailed Implementation

[0053] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0054] First Embodiment

[0055] Please refer to the following: Figures 1-10 The present invention provides a calcining furnace for separating and recovering tantalum and niobium from tin slag, comprising: a base 1;

[0056] Furnace body 2, which is mounted on the base 1, and a burner 3 is mounted on the top of the furnace body 2. The furnace body 2 is used to feed tin dross powder to achieve roasting.

[0057] A stirring assembly 4 is installed inside the furnace body 2. The stirring assembly 4 is used for mixing and stirring tin slag powder during roasting. A groove 5 is provided on the inner wall of the furnace body 2. The stirring assembly 4 includes a first stirring structure 41 and a second stirring structure 42. The first stirring structure 41 is installed on the furnace body 2, and the second stirring structure 42 is installed in the groove 5. During stirring, both the first stirring structure 41 and the second stirring structure 42 rotate.

[0058] Feeding assembly 6, which is installed inside the furnace body 2, is used for feeding tin dross powder;

[0059] Discharge assembly 7 is installed at the bottom of the furnace body 2 and is used to discharge the roasted product.

[0060] A drive assembly 8 is mounted on the furnace body 2 and is used to drive the stirring assembly 4 to rotate.

[0061] A flue gas exhaust pipe 9 is installed on the furnace body 2, and a filter element 10 is installed inside the flue gas exhaust pipe 9.

[0062] Cleaning component 11 is installed inside the furnace body 2 and is used for cleaning the filter element 10.

[0063] In this embodiment, the furnace body 2 is also equipped with a control panel for controlling the opening and closing of each component of the device and its operating parameters.

[0064] Furthermore, the burner 3 adopts conventional combustion equipment in this field, including fuel supply components, ignition components and combustion components, which are relatively mature technologies in this field. It only needs to meet the requirement of realizing the combustion function, and will not be described in detail here.

[0065] In this embodiment, the groove 5 includes a sealing groove and an opening groove. The sealing ring 421 is rotatably connected in the sealing groove and ensures sealing, allowing the sealing ring 421 to rotate in the groove 5. The opening groove provides space for the gear 87 to mesh with the gear ring 422.

[0066] In this embodiment, the flue gas exhaust pipe 9 is used to discharge the high-temperature flue gas generated during the roasting of the furnace body 2, and the filter element 10 is used to filter out impurities such as dust particles carried in the high-temperature flue gas.

[0067] Furthermore, the filter element 10 may include, but is not limited to, filter plates, filter screens, etc. It only needs to filter dust particles and other impurities carried by high-temperature flue gas. The parameters of the filter pores of the filter element 10 can be selected according to actual needs and are not limited here.

[0068] Please refer to the following: Figure 2 , Figure 3 and Figure 4 The first stirring structure 41 includes a rotating shaft 411, a first stirring blade 412, a first bevel gear 413, and an eccentric wheel 414. The rotating shaft 411 is rotatably connected inside the furnace body 2. One end of the rotating shaft 411 passes through the furnace body 2 and extends to the outside of the furnace body 2. The first stirring blade 412 is fixed to the outer surface of the rotating shaft 411. The first bevel gear 413 is fixed to one end of the rotating shaft 411. The eccentric wheel 414 is fixed to the outer surface of the rotating shaft 411.

[0069] In this embodiment, the sealing performance of the connection point must be ensured when the rotating shaft 411 passes through the furnace body 2.

[0070] Furthermore, there are multiple first stirring blades 412.

[0071] Please refer to the following: Figure 9 In the initial state, the outer surfaces of the first bevel gear 413 and the second bevel gear 84 mesh. When in use, when the drive component 8 rotates, it will drive the first bevel gear 413 to rotate through the second bevel gear 84, thereby causing the rotating shaft 411 to rotate and the first stirring blade 412 to rotate longitudinally, thereby enabling the mixing and stirring of materials such as tin dross powder.

[0072] In this embodiment, the eccentric wheel 414 is located at the bottom of the fixed plate 113. When the rotating shaft 411 rotates, it will also drive the eccentric wheel 414 to rotate, thereby enabling the cleaning component 11 to move up and down reciprocally to clean the filter element 10 and scrape off the dust particles and other impurities attached to its surface, thereby avoiding clogging and avoiding affecting the filtration effect.

[0073] Please refer to it again. Figure 3 and Figure 4The second stirring structure 42 includes a sealing ring 421, a toothed ring 422, a scraper 423, and a second stirring blade 424. The sealing ring 421 is rotatably connected to the groove 5. The toothed ring 422 is fixed to the outer surface of the sealing ring 421. The scraper 423 is fixed to the inner surface of the sealing ring 421. The second stirring blade 424 is fixed to the scraper 423.

[0074] In this embodiment, the bottom of the furnace body 2 is conical to facilitate material discharge, and the scraper 423 is also conical and abuts against the inner wall of the furnace body 2.

[0075] Furthermore, there are multiple second stirring blades 424, which are staggered with the first stirring blades 412.

[0076] Please refer to it again. Figure 9 When the drive component 8 rotates, it drives the gear ring 422 to rotate through the gear 87, which in turn causes the sealing ring 421 to rotate and drives the scraper 423 to rotate. This enables the second stirring blade 424 to rotate laterally, which, in conjunction with the longitudinal rotation of the first stirring blade 412, provides lateral shearing force to evenly disperse the material, thereby improving the uniformity of material mixing and the uniformity of heating during roasting.

[0077] Please refer to the following: Figure 2 and Figure 5 The feeding assembly 6 includes a heat exchange box 61, a mounting plate 62, a first feed pipe 63, a second feed pipe 64, and a heat exchange coil 65. The heat exchange box 61 is fixed to the top of the furnace body 2, the mounting plate 62 is mounted on the right side of the heat exchange box 61, the first feed pipe 63 is mounted on the top of the heat exchange box 61, the second feed pipe 64 is mounted on the bottom of the heat exchange box 61 and communicates with the furnace body 2, and the heat exchange coil 65 is mounted on the mounting plate 62.

[0078] In this embodiment, both the first feed pipe 63 and the second feed pipe 64 are equipped with electrically controlled valves to control their on / off states.

[0079] In this embodiment, after the heat exchange coil 65 receives the high-temperature flue gas from the flue gas exhaust pipe 9, it can exchange heat with the material inside the heat exchange box 61, thereby preheating the newly entered material, improving the heat utilization rate, and playing an energy-saving role.

[0080] When in use, after the first feed pipe 63 is opened, the material enters the interior of the heat exchange box 61. At this time, the material will come into contact with the heat exchange coil 65 for heat exchange. After the heat exchange is completed, the material can enter the furnace body 2 for roasting through the opening of the second feed pipe 64.

[0081] Please refer to it again. Figure 5The heat exchange box 61 is open on the right side, the mounting plate 62 is detachably connected to the right side of the heat exchange box 61, and one end of the heat exchange coil 65 is detachably connected to one end of the flue gas exhaust pipe 9 through a connector.

[0082] In this embodiment, the detachable connection of the mounting plate 62 facilitates its removal, thereby making it easier to remove the heat exchange coil 65 for maintenance and improving ease of use.

[0083] In this embodiment, one end of the heat exchange coil 65 is connected to the flue gas exhaust pipe 9 to receive high-temperature flue gas, and the other end of the heat exchange coil 65 is connected to the inlet of the flue gas purification device to send the high-temperature flue gas into the flue gas purification device for purification before discharge.

[0084] Preferably, the flue gas purification device adopts existing technology.

[0085] Please refer to the following: Figure 2 and Figure 6 The discharge assembly 7 includes a discharge trough 71, a pusher 72, an inclined plate 73, a sealing plate 74, and a protrusion 75. The discharge trough 71 is installed at the bottom of the furnace body 2, the pusher 72 is fixed on the discharge trough 71, the inclined plate 73 is installed at the output end of the pusher 72, the sealing plate 74 is fixed on the inclined plate 73, and the protrusion 75 is installed at the bottom of the discharge trough 71.

[0086] In this embodiment, the pushing component 72 may include, but is not limited to, electric actuators, cylinders, hydraulic rods, or linear motors, as long as it can drive the inclined plate 73 to move linearly in the horizontal direction.

[0087] Furthermore, the sealing plate 74 and the discharge trough 71 are sealed together. When the sealing plate 74 moves horizontally to block the discharge trough 71, the discharge trough 71 can be completely blocked.

[0088] Preferably, the protrusion 75 can further improve the sealing performance after the sealing plate 74 comes into contact with it.

[0089] Please refer to the following: Figure 10 When in use, the extension of the pusher 72 can drive the inclined plate 73 to move to the left, thereby causing the sealing plate 74 to move to the left, opening the discharge chute 71, and enabling the discharge of the roasted product.

[0090] During material discharge, after the pusher 72 extends and drives the inclined plate 73 to move to the left, the inclined plate 73 no longer supports the roller 88. At this time, the sliding rod 83 can move down, so that the second bevel gear 84 separates from the first bevel gear 413, while the gear 87 still meshes with the gear ring 422. When the sliding rod 83 rotates, it will only drive the second stirring structure 42 to rotate, so that it can play the function of scraping and unblocking during material discharge, and can reduce power output, thus achieving energy saving effect.

[0091] Please refer to the following: Figure 2 and Figure 7 The drive assembly 8 includes a drive component 81, a first sleeve rod 82, a sliding rod 83, a second bevel gear 84, a fixing block 85, a second sleeve rod 86, a gear 87, and a roller 88. The drive component 81 is fixed to the furnace body 2. The first sleeve rod 82 is fixed to the output shaft of the drive component 81. The sliding rod 83 is slidably connected inside the first sleeve rod 82. The second bevel gear 84 is fixed to the outer surface of the sliding rod 83. The fixing block 85 is fixed to the furnace body 2. The second sleeve rod 86 is rotatably connected to the fixing block 85. The second sleeve rod 86 is slidably connected to the sliding rod 83. The gear 87 is fixed to the outer surface of the second sleeve rod 86. The roller 88 is installed at the bottom end of the sliding rod 83.

[0092] In this embodiment, the driving component 81 may include, but is not limited to, a motor, a pneumatic motor, or a hydraulic motor, and only needs to drive the first rod 82 to rotate.

[0093] Preferably, the drive component 81 rotates several revolutions each time, thereby ensuring that the roller 88 can be used in conjunction with the inclined plate 73 after each rotation.

[0094] In this embodiment, a vacuum structure is formed between the first sleeve rod 82 and the sliding rod 83, which increases the air pressure when the sliding rod 83 retracts into the first sleeve rod 82, making it easier for the sliding rod 83 to slide downward stably.

[0095] In one embodiment, a repulsion structure is provided between the first sleeve rod 82 and the sliding rod 83. The repulsion structure includes two magnets with the same pole facing each other. One magnet is installed on the top of the inner wall of the first sleeve rod 82, and the other magnet is installed on the top of the sliding rod 83, so that when the sliding rod 83 retracts into the first sleeve rod 82, the two magnets approach each other and repel each other.

[0096] In other embodiments, other elastic structures, including but not limited to springs, may be provided between the sliding rod 83 and the first sleeve rod 82.

[0097] In one embodiment, a limiting structure is provided between the sliding rod 83 and the second sleeve rod 86. The limiting structure includes a limiting block and a limiting groove. The limiting block is fixed to the outer surface of the sliding rod 83, and the limiting groove is opened on the inner surface of the second sleeve rod 86 in a vertical shape. The limiting block is slidably connected in the limiting groove. The setting of this limiting structure can ensure that the sliding rod 83 can slide smoothly up and down inside the second sleeve rod 86, and when the sliding rod 83 rotates, it will drive the second sleeve rod 86 to rotate through the limiting block and the limiting groove.

[0098] In use, the drive component 81 drives the first sleeve rod 82 to rotate, which in turn causes the sliding rod 83 to rotate, which in turn causes the second bevel gear 84 to rotate. At the same time, the rotation of the sliding rod 83 also drives the second sleeve rod 86 to rotate, which in turn causes the gear 87 to rotate. This drives the first bevel gear 413 and the gear ring 422, causing the first stirring structure 41 and the second stirring structure 42 to rotate, thereby achieving the mixing of materials.

[0099] Please refer to the following: Figure 2 and Figure 8 The cleaning assembly 11 includes a fixed frame 111, a sliding block 112, a fixed plate 113, an elastic element 114, a connecting rod 115, and a cleaning component 116. The fixed frame 111 is fixed to the side wall of the furnace body 2. The sliding block 112 is slidably connected to the fixed frame 111. The fixed plate 113 is fixed to the bottom of the sliding block 112 and extends through the fixed frame 111 to the bottom of the fixed frame 111. The elastic element 114 is disposed between the sliding block 112 and the fixed frame 111. The connecting rod 115 is fixed to the top of the sliding block 112 and extends through the fixed frame 111 to the top of the fixed frame 111. The cleaning component 116 is fixed to the top of the connecting rod 115.

[0100] In this embodiment, the elastic element 114 includes, but is not limited to, springs, elastic ribs, and pneumatic piston cylinders, etc., as long as it provides a downward reaction force when the sliding block 112 moves upward.

[0101] In this embodiment, the cleaning component 116 includes, but is not limited to, a scraper or the like.

[0102] In use, when the rotating shaft 411 drives the eccentric wheel 414 to rotate, it will push the fixed plate 113 upward, thereby causing the sliding block 112 to move upward and squeeze the elastic element 114. The elastic element 114 will then rebound due to its elastic force, causing the sliding block 112 to move downward. This causes the sliding block 112 to move up and down repeatedly, which in turn causes the connecting rod 115 to drive the cleaning element 116 to move up and down repeatedly, cleaning the filter element 10 and preventing the filter element 10 from becoming clogged.

[0103] The working principle of the calcining furnace and method for separating and recovering tantalum and niobium from tin dross provided by this invention is as follows:

[0104] Tin dross powder, potassium bisulfate, and sulfuric acid are added to the furnace body 2 through the feeding assembly 6. At this time, the drive component 81 starts to rotate, driving the first sleeve rod 82 to rotate, which in turn causes the sliding rod 83 to rotate, driving the second bevel gear 84 to rotate, which in turn causes the first bevel gear 413 to rotate, driving the rotating shaft 411 to rotate, which in turn causes the first stirring blade 412 to rotate longitudinally. The rotation of the sliding rod 83 also drives the second sleeve rod 86 to rotate, which in turn causes the gear 87 to rotate, driving the gear ring 422 to rotate, which in turn causes the sealing ring 421 to rotate, driving the scraper 423 to rotate, which in turn causes the second stirring blade 424 to rotate laterally, mixing and stirring the materials. Then the burner 3 is turned on for roasting.

[0105] The high-temperature flue gas generated during combustion is discharged into the heat exchange coil 65 through the flue gas exhaust pipe 9. The heat exchange coil 65 exchanges heat with the material to preheat the material entering next time. When the high-temperature flue gas enters the flue gas exhaust pipe 9, it will pass through the filter element 10 to filter out particulate impurities. When the rotating shaft 411 rotates, it will drive the eccentric wheel 414 to rotate, which will cause the cleaning component 11 to move up and down to clean the filter element 10 and prevent the filter element 10 from clogging.

[0106] After the material is roasted, the extension of the pusher 72 causes the inclined plate 73 to move to the left, which in turn causes the sealing plate 74 to move to the left, allowing the discharge chute 71 to open and discharge the material.

[0107] During material discharge, after the inclined plate 73 moves to the left, it no longer supports the roller 88. At this time, the sliding rod 83 will slide downward, which will cause the second bevel gear 84 to move downward and no longer mesh with the first bevel gear 413. At this time, in conjunction with the rotation of the drive component 81, the sliding rod 83 will rotate, which will drive the second set of rods 86 to rotate, which will cause the gear 87 to rotate, which will drive the gear ring 422 to rotate, which will then drive the sealing ring 421 to rotate, which will drive the scraper 423 to rotate, scraping the material at the bottom of the inner wall of the furnace body 2 while avoiding material discharge blockage.

[0108] Compared with related technologies, the calcining furnace and method for separating and recovering tantalum and niobium from tin dross provided by the present invention have the following beneficial effects:

[0109] This invention utilizes the longitudinal rotation of the first stirring structure 41 to mix materials, while the transverse rotation of the second stirring structure 42 provides transverse shearing force. This avoids the formation of dead zones in a single stirring surface, improving the uniformity of material mixing. Furthermore, it can turn the materials over during roasting, ensuring thorough roasting and thus improving tantalum and niobium recovery efficiency. When the first stirring structure 41 rotates, it can also coordinate with the cleaning component 11 to reciprocate and clean the filter element 10, preventing clogging and reducing manual maintenance costs. The extension of the pusher 72 allows the discharge chute 71 to open and discharge materials. During discharge, it can also coordinate with the rotation of the drive component 81 to rotate the second stirring structure 42, causing the scraper 423 to rotate and scrape the material from the bottom of the inner wall of the furnace body 2. This prevents the material from adhering to the inner wall and forming rings, while also preventing material from accumulating at the outlet and causing blockage during discharge.

[0110] Second Embodiment

[0111] The present invention also provides a method for separating and recovering tantalum and niobium from tin dross, comprising the aforementioned calcining furnace for separating and recovering tantalum and niobium from tin dross and the following steps:

[0112] S1. Dry and crush the tin dross, and sieve it to a particle size of <75μm to obtain tin dross powder;

[0113] S2. Add tin dross powder, potassium bisulfate, and sulfuric acid to furnace body 2, mix them at a ratio of 1g:0.5g:0.5mL, and calcine at 300℃ for 2 hours to obtain the calcined product.

[0114] S3. The calcined product is mixed with oxalic acid solution at a solid-liquid ratio of 50 g / L and leached for 1 hour at a temperature of 60°C. The mixture is then filtered to obtain the leachate and residue. The residue contains ZrO2 and CaO. It is washed three times with ultrapure water to remove residual oxalic acid and metal ions. The residue can be further extracted as zirconium or used as a building material raw material.

[0115] S4. Adjust the pH of the leachate to 1.5-2.0 using dilute sulfuric acid, so that Fe... 3+ Al 3+ Hydrolysis produces Fe(OH)3 and Al(OH)3 precipitates, which are removed by filtration to obtain filtrate one;

[0116] S5. Add filtrate one to sodium carbonate solution to remove calcium ions and obtain filtrate two.

[0117] S6. Mix the extractant methyl isobutyl ketone with filtrate II at a volume ratio of 1:1, shake for 5 min, and separate to obtain an organic phase containing tantalum and niobium.

[0118] S7. The tantalum-niobium-containing organic phase is back-extracted with pure water and 5% sulfuric acid solution respectively to obtain tantalum-containing back-extraction solution and niobium-containing back-extraction solution;

[0119] S8. Add excess ammonia (pH>9) to the back-extraction solution, stir, and filter to obtain tantalum hydroxide and niobium hydroxide;

[0120] S9. Tantalum hydroxide and niobium hydroxide were calcined at 800℃ for 2 hours to obtain tantalum pentoxide and niobium pentoxide.

[0121] Compared with related technologies, the calcining furnace and method for separating and recovering tantalum and niobium from tin dross provided by the present invention have the following beneficial effects:

[0122] The method of this invention avoids the use of highly toxic hydrofluoric acid, reduces environmental pollution, and lowers energy and reagent consumption.

[0123] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A calcining furnace for separating and recovering tantalum and niobium from tin slag, characterized in that, include: Base; A furnace body is mounted on the base, and a burner is installed on the top of the furnace body. The furnace body is used to feed tin dross powder for roasting. A stirring assembly is installed inside the furnace body. The stirring assembly is used for mixing and stirring tin slag powder during roasting. A groove is provided on the inner wall of the furnace body. The stirring assembly includes a first stirring structure and a second stirring structure. The first stirring structure is installed on the furnace body, and the second stirring structure is installed in the groove. During stirring, both the first stirring structure and the second stirring structure rotate. A feeding assembly is installed inside the furnace body and is used for feeding tin dross powder; A discharge assembly is installed at the bottom of the furnace body and is used to discharge the roasted product. A drive assembly, which is mounted on the furnace body, is used to drive the stirring assembly to rotate; A flue gas exhaust pipe is installed on the furnace body, and a filter element is installed inside the flue gas exhaust pipe; A cleaning assembly is installed inside the furnace body and is used for cleaning the filter element.

2. The calcining furnace for separating and recovering tantalum and niobium from tin slag according to claim 1, characterized in that, The first stirring structure includes a rotating shaft, a first stirring blade, a first bevel gear, and an eccentric wheel. The rotating shaft is rotatably connected to the furnace body, one end of the rotating shaft passes through the furnace body and extends to the outside of the furnace body, the first stirring blade is fixed to the outer surface of the rotating shaft, the first bevel gear is fixed to one end of the rotating shaft, and the eccentric wheel is fixed to the outer surface of the rotating shaft.

3. The calcining furnace for separating and recovering tantalum and niobium from tin slag according to claim 2, characterized in that, The second stirring structure includes a sealing ring, a toothed ring, a scraper, and a second stirring blade. The sealing ring is rotatably connected to the groove, the toothed ring is fixed to the outer surface of the sealing ring, the scraper is fixed to the inner surface of the sealing ring, and the second stirring blade is fixed to the scraper.

4. The calcining furnace for separating and recovering tantalum and niobium from tin slag according to claim 1, characterized in that, The feeding assembly includes a heat exchange box, a mounting plate, a first feed pipe, a second feed pipe, and a heat exchange coil. The heat exchange box is fixed to the top of the furnace body, the mounting plate is installed on the right side of the heat exchange box, the first feed pipe is installed on the top of the heat exchange box, the second feed pipe is installed on the bottom of the heat exchange box and communicates with the furnace body, and the heat exchange coil is installed on the mounting plate.

5. The calcining furnace for separating and recovering tantalum and niobium from tin slag according to claim 4, characterized in that, The heat exchange box has an open side, the mounting plate is detachably connected to the right side of the heat exchange box, and one end of the heat exchange coil is detachably connected to one end of the flue gas exhaust pipe via a connector.

6. The calcining furnace for separating and recovering tantalum and niobium from tin slag according to claim 1, characterized in that, The discharge assembly includes a discharge trough, a pusher, an inclined plate, a sealing plate, and a protrusion. The discharge trough is installed at the bottom of the furnace body, the pusher is fixed on the discharge trough, the inclined plate is installed at the output end of the pusher, the sealing plate is fixed on the inclined plate, and the protrusion is installed at the bottom of the discharge trough.

7. The calcining furnace for separating and recovering tantalum and niobium from tin slag according to claim 1, characterized in that, The drive assembly includes a drive component, a first sleeve rod, a sliding rod, a second bevel gear, a fixing block, a second sleeve rod, a gear, and a roller. The drive component is fixed to the furnace body, the first sleeve rod is fixed to the output shaft of the drive component, the sliding rod is slidably connected inside the first sleeve rod, the second bevel gear is fixed to the outer surface of the sliding rod, the fixing block is fixed to the furnace body, the second sleeve rod is rotatably connected to the fixing block, the second sleeve rod is slidably connected to the sliding rod, the gear is fixed to the outer surface of the second sleeve rod, and the roller is installed at the bottom end of the sliding rod.

8. The calcining furnace for separating and recovering tantalum and niobium from tin slag according to claim 1, characterized in that, The cleaning assembly includes a fixed frame, a sliding block, a fixed plate, an elastic element, a connecting rod, and a cleaning component. The fixed frame is fixed to the side wall of the furnace body. The sliding block is slidably connected within the fixed frame. The fixed plate is fixed to the bottom of the sliding block and extends through the fixed frame to the bottom of the fixed frame. The elastic element is disposed between the sliding block and the fixed frame. The connecting rod is fixed to the top of the sliding block and extends through the fixed frame to the top of the fixed frame. The cleaning component is fixed to the top of the connecting rod.

9. A method for separating and recovering tantalum and niobium from tin dross, characterized in that, Includes the calcining furnace for separating and recovering tantalum and niobium from tin dross as described in any one of claims 1-8, and the following steps: S1. Dry, crush, and sieve the tin dross to obtain tin dross powder; S2. Add tin dross powder, potassium bisulfate, and sulfuric acid into the furnace body, mix them in a certain proportion, and then perform roasting treatment to obtain the roasted product. S3. The roasted product is mixed with oxalic acid solution in a certain proportion and leached, filtered to obtain leachate and residue; the residue contains ZrO2 and CaO, and is washed with ultrapure water to remove residual oxalic acid and metal ions, which can be further extracted as zirconium or used as building material raw material. S4. Adjust the pH of the leachate, filter it, and obtain filtrate one. S5. Add filtrate one to sodium carbonate solution to remove calcium ions and obtain filtrate two. S6. Mix the extractant methyl isobutyl ketone with filtrate 2, shake and separate to obtain an organic phase containing tantalum and niobium; S7. The tantalum-niobium-containing organic phase is back-extracted with pure water and sulfuric acid solution respectively to obtain tantalum-containing back-extraction solution and niobium-containing back-extraction solution; S8. Add ammonia to the back-extraction solution, stir, and filter to obtain tantalum hydroxide and niobium hydroxide; S9. Tantalum hydroxide and niobium hydroxide are calcined to obtain tantalum pentoxide and niobium pentoxide.

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