Oxidation reaction kettle

Abstract

The utility model relates to an oxidation reaction kettle which comprises a kettle body, an upper sealing head and a lower sealing head, the upper sealing head and the lower sealing head are positioned at the upper end and the lower end of the kettle body, a feeding hole is formed in the upper sealing head, and a discharging hole and an air inlet are formed in the side surface of the kettle body; a stirrer is arranged in the kettle body and comprises a stirring shaft, a rotor and a stator, the rotor is connected with the stirring shaft, the stator is of a hollow cylinder structure and is arranged on the outer side of the rotor in a sleeving mode, and the lower end of the stator is in fixed contact with the upper surface of the lower sealing head; the upper end of the stator is communicated with the air inlet through an air inlet pipeline; the stator is provided with a plurality of holes and a plurality of grooves. The oxidation reaction kettle provided by the utility model can quickly, uniformly and smoothly realize an oxidation process, and has the advantages of reducing cost and improving efficiency.

Description

Technical Field

[0001] The utility model relates to the technical field of chemical production synthesis equipment, in particular to an oxidation reaction kettle. Background Art

[0002] As a pigment, the iron oxide red used by humans at the beginning was all natural iron oxide minerals, which were used as pigments after being crushed. With the development needs of the industry, chemical synthesis of iron oxide red pigments began. The products are purer and have more excellent performance, and now they have gradually replaced natural products. The process route of iron oxide red pigments now basically adopts the wet production process, such as the iron sheet method (reacting iron sheet with sulfuric acid to generate ferrous sulfate) process, and the ferrous sulfate method (mostly ferrous sulfate by-produced in titanium dioxide production) process, etc. The wet production of iron oxide red generally goes through two steps. First is the preparation of crystal seeds, and then the two-step oxidation is carried out with the obtained crystal seeds as the base material. At present, the two-step reaction of wet production of iron oxide red is often completed in two sets of equipment.

[0003] For example, the prior art CN209113504U discloses an equipment system for producing iron oxide pigments from alkali-circulated iron-containing solid waste, including a ferrous sulfate solution preparation system, an iron oxide red pigment crystal seed preparation system, and an energy-saving and environmental-friendly iron oxide red pigment oxidation reaction system; the iron oxide red pigment crystal seed preparation system consists of a special reactor for crystal seed preparation, a tail gas collection and purification system, a coolant circulation tank, a refrigeration unit, and a cooling tower, and the energy-saving and environmental-friendly iron oxide red pigment oxidation reaction system includes a special reactor for oxidation synthesis. This process prepares and produces iron oxide pigments through more than two sets of equipment. The preparation of crystal seeds and the oxidation reaction are carried out in two systems respectively, with cumbersome operations and relatively high preparation costs, which affect the industrial production effect of wet production of iron oxide red.

[0004] At present, the new energy industry has developed rapidly. As one of the cathode materials of lithium-ion batteries, lithium iron phosphate has greater advantages of safety, low cost, long cycle life, and potential for fast charging compared with other types. Therefore, since its commercialization, it has been widely applied to many fields including new energy vehicles, ships, and energy storage. With the rapid development of the new energy industry, the number of retired new energy batteries is about to increase explosively. At present, the wet acid leaching process is mostly used to recover lithium resources in waste lithium iron phosphate cathode powder, that is, acid leaching and oxidation to dissolve lithium with an oxidant (hydrogen peroxide or sodium chlorate, etc.) in an acidic system (sulfuric acid or hydrochloric acid). The consumption of oxidant, acid, and subsequent acid adjustment and alkali consumption are high, and the cost is significantly high. Therefore, it is necessary to find an oxidant with low cost and excellent effect, and provide a reaction system or reaction equipment that can improve the oxidation effect and acid utilization rate.

[0005] Therefore, providing a reaction kettle that can simplify the process production, optimize the operation environment, and improve the oxidation effect at the same time has become an urgent technical problem to be solved at present. Summary of the Utility Model

[0006] To solve the above technical problems, the purpose of the present utility model is to provide an oxidation reactor. The oxidation reactor provided by the present utility model can quickly, evenly and smoothly realize the oxidation process flow, and has the advantages of cost reduction and efficiency improvement.

[0007] To achieve this purpose, the present utility model adopts the following technical solutions:

[0008] The present utility model provides an oxidation reactor, which includes a reactor body, an upper head and a lower head located at the upper and lower ends of the reactor body. The upper head is provided with a feed inlet, and the side of the reactor body is provided with a discharge outlet and an air inlet.

[0009] A stirrer is arranged inside the reactor body. The stirrer includes a stirring shaft, a rotor and a stator. The rotor is connected to the stirring shaft. The stator is a hollow cylindrical structure and is sleeved outside the rotor. The lower end of the stator is fixedly in contact with the upper surface of the lower head, and the upper end of the stator is connected to the air inlet through an air inlet pipe. A plurality of holes and a plurality of grooves are formed in the stator.

[0010] In the present utility model, "the stator is a hollow cylindrical structure and is sleeved outside the rotor" means that the rotor is located in the hollow area formed by the stator and the lower head.

[0011] In the present utility model, the number of the air inlets can be selected as one or two. When the number of the air inlets is two, the air inlets include a first air inlet and a second air inlet respectively arranged on the opposite sides of the reactor body. The first air inlet is connected to the upper end of the stator through a first air inlet pipe, and the second air inlet is connected to the upper end of the stator through a second air inlet pipe.

[0012] In the present utility model, the "a plurality of" all refer to a number of two or more.

[0013] As a preferred technical solution of the present utility model, the lower end of the stirring shaft is fixed on the upper surface of the lower head through a limit block.

[0014] Preferably, the limit block is located between the lower head and the rotor.

[0015] There is no contact between the limit block and the rotor in the present utility model, and there is a certain distance between them.

[0016] Preferably, the stirring shaft is located in the middle area of the reactor body and is perpendicular to the surfaces of the lower head and the upper head.

[0017] The agitator shaft of the present utility model being located in the middle region of the kettle body means that with the direction parallel to the surface of the upper head as the horizontal direction, the agitator shaft is located in the middle of the kettle body in the horizontal direction.

[0018] Preferably, the upper end of the agitator shaft penetrates through the upper head and extends to the outside of the kettle body.

[0019] As a preferred technical solution of the present utility model, the oxidation reaction kettle further includes an electric drive device located outside the kettle body.

[0020] Preferably, the electric drive device includes a motor bracket, a frame and a motor arranged in sequence from bottom to top, and the electric drive device is fixed in the middle region of the upper surface of the upper head on the side away from the kettle body through the motor bracket.

[0021] Preferably, the motor bracket is fixed to the upper head through a support ear.

[0022] Preferably, the frame is located on the side of the motor bracket away from the upper head and is fixedly connected to the motor bracket through a fixing member.

[0023] In the present utility model, the frame is connected to the motor bracket through a flange or internal thread and is fastened with bolts.

[0024] Preferably, the motor is fixed above the frame, the rotating shaft of the motor is vertically installed on the motor bracket through the frame downward, and the rotating shaft of the motor is connected to the upper end of the agitator shaft through a coupling.

[0025] The present utility model drives the agitator shaft to rotate through the motor, thereby further driving the rotor connected to the agitator shaft to rotate.

[0026] As a preferred technical solution of the present utility model, the stator includes an upper cover and a side wall surface connected to the outer edge of the side of the upper cover away from the agitator shaft.

[0027] Preferably, the upper cover of the stator is arranged perpendicular to the axial direction of the agitator shaft, and the upper cover of the stator is an annular structure with a central opening.

[0028] Preferably, the agitator shaft passes through the central opening of the upper cover of the stator.

[0029] Preferably, the ratio of the outer diameter of the stator to the inner diameter of the kettle body is 1:(1.25 - 5), such as 1:1.25, 1:1.50, 1:2.00, 1:2.50, 1:3.00, 1:3.50, 1:4.00, 1:4.50 or 1:5.00, etc.

[0030] Preferably, the several holes formed in the stator are circular holes, and the circular holes are arranged in an array and penetrate through the upper cover of the stator.

[0031] Preferably, the circular holes are arranged radially with the center of the upper cover as the center, and are distributed radially from the inside to the outside. The connecting lines of the centers of the circular holes at the same radial length form several concentric circles on the upper cover.

[0032] Preferably, the circular holes on the concentric circles at the same radial length are arranged at equal angular intervals.

[0033] Preferably, the number of the circular holes on the concentric circles at the same radial length is more than 8, such as 8, 9, 10, 11 or 12, etc.

[0034] Preferably, the number of the concentric circles is more than 4, such as 4, 5, 6, 7 or 8, etc.

[0035] Preferably, the pore diameter of the circular holes is 2 mm or more, such as 2.0 mm, 2.2 mm, 2.4 mm, 2.6 mm, 2.8 mm, 3.0 mm, 3.2 mm, 3.4 mm, 3.6 mm, 3.8 mm or 4.0 mm, etc.

[0036] Preferably, the opening ratio of the upper cover of the stator is 10% or more, such as 10%, 12%, 14%, 16%, 18% or 20%, etc.

[0037] In the present utility model, the "opening ratio" refers to the percentage of the sum of the areas of several circular holes on the upper cover of the stator in the total area of the upper cover of the stator.

[0038] As a preferred technical solution of the present utility model, the several grooves formed in the stator are arranged at intervals along the circumferential direction of the side wall surface of the stator.

[0039] Preferably, the grooves are arranged at equal intervals.

[0040] Preferably, the depth direction of the grooves extends towards the direction close to the upper surface of the lower sealing head.

[0041] As a preferred technical solution of the present utility model, the rotor includes an annular side surface, a bottom bracket and several blades, and the annular side surface and the blades are vertically fixed on the bottom bracket.

[0042] Preferably, the annular side surface surrounds the outer circumference of the stirring shaft, the several blades are arranged circumferentially along the inner surface of the annular side surface, one end of the blade is fixedly connected to the inner wall of the annular side surface, and the other end is arranged at an interval from the stirring shaft.

[0043] Preferably, the bottom bracket of the rotor is parallel to the lower head, and there is a gap between the rotor and the lower head.

[0044] In the present utility model, the spacing distance between the paddle and the stirring shaft, as well as the spacing distance between the rotor and the lower head, are not specifically limited, as long as the gas introduced from the air inlet can be dispersed under the action of the rotor and the stator to form an air flow with good uniformity and high fluidity.

[0045] Preferably, taking the direction parallel to the surface of the lower head as the horizontal direction, in the horizontal direction, the direction of the paddle forms an angle of 30 - 60° with the direction perpendicular to the tangent direction of the circle where the annular side surface is located, such as 30°, 35°, 40°, 45°, 50°, 55° or 60°, etc.

[0046] As a preferred technical solution of the present utility model, the oxidation reactor further includes a coil heat exchanger.

[0047] The present utility model can selectively set a coil heat exchanger in the oxidation reactor to heat or cool the reaction materials and regulate the temperature control process required for different reactions.

[0048] Preferably, the coil heat exchanger is arranged in a spiral shape on the inner wall of the side surface of the reactor body.

[0049] Preferably, the upper end of the coil heat exchanger is located below the upper head, and the distance between the upper end of the coil heat exchanger and the upper head is 30 - 40 cm, such as 30 cm, 32 cm, 34 cm, 36 cm, 38 cm or 40 cm, etc.

[0050] Preferably, the lower end of the coil heat exchanger is located above the lower head, and the distance between the lower end of the coil heat exchanger and the lower head is 30 - 40 cm, such as 30 cm, 32 cm, 34 cm, 36 cm, 38 cm or 40 cm, etc.

[0051] As a preferred technical solution of the present utility model, the oxidation reactor further includes an oxidation blower externally connected to the air inlet.

[0052] As a preferred technical solution of the present utility model, the oxidation reactor is further provided with a functional port, and the functional port is connected to the upper head from top to bottom through a functional pipeline and extends into the reactor body.

[0053] Preferably, the oxidation reactor is further provided with a spare port, and the spare port is connected to the upper head from top to bottom through a spare pipeline and extends into the reactor body.

[0054] Preferably, the feed port is connected to the upper head from top to bottom through a feed pipeline and extends into the reactor body.

[0055] As a preferred technical solution of the present utility model, the feed inlet and the connected feed pipeline, the function port and the connected function pipeline, and the spare port and the connected spare pipeline are fixed by the same fixing member and communicated with the upper head and extend into the interior of the kettle body.

[0056] The oxidation reaction kettle provided by the present utility model can be used in the production process of iron oxide red. The specific process includes the following steps:

[0057] (A) Add ammonia water and ferrous sulfate from the feed inlet provided above the kettle body into the interior of the kettle body to form a mixed solution. Adjust the addition amounts of the ammonia water and ferrous sulfate so that the pH of the mixed solution is 8.5 - 9.5. Turn on the motor to drive the rotor connected to the stirring shaft to rotate at a speed of 0 - 900 revolutions per minute. At the same time, turn on the oxidation blower to introduce air into the air inlet, and then introduce the air flow into the hollow area of the stator through the air inlet pipeline. Under the rotation of the rotor, the air inside the hollow area of the stator is evenly dispersed from the round holes on the upper cover of the stator and the grooves on the side wall surface into the interior of the kettle body to oxidize the mixed solution inside the kettle body, and iron oxide trihydrate seeds are prepared.

[0058] (B) Continuously add ammonia water and ferrous sulfate into the interior of the kettle body through the feed inlet, keep the pH of the mixed solution inside the kettle body at 8.5 - 9.5, and at the same time continue to use the oxidation blower to introduce air into the air inlet. The air enters the hollow area of the stator through the air inlet pipeline. The rotor rotates continuously at a speed of 0 - 900 revolutions per minute, and the air is evenly dispersed from the round holes on the upper cover of the stator and the grooves on the side wall surface into the interior of the kettle body. Under the oxidation condition of the air, the mixed product of ferrous sulfate and ammonia water continues to generate iron oxide trihydrate on the iron oxide trihydrate seeds obtained in step (A). At the same time, the generated sulfuric acid is neutralized with the added ammonia water to obtain iron oxide trihydrate nuclei.

[0059] (C) Continue step (B). The iron oxide trihydrate nuclei obtained in step (B) gradually grow until the iron oxide red is generated, and the obtained iron oxide red is collected through the discharge port.

[0060] The oxidation reaction kettle provided by the present utility model can be used in the oxidation process in the recycling production of lithium iron phosphate waste. The specific process includes the following steps:

[0061] Place the lithium iron phosphate cathode black powder in the lithium iron phosphate battery into the kettle body, introduce acid solution through the feed port to dissolve the lithium iron phosphate cathode black powder in the kettle body, turn on the motor above the kettle body to drive the stirring shaft and the rotor connected to the stirring shaft to rotate at a speed of 0 - 900 revolutions per minute. At the same time, turn on the oxidation blower to introduce air into the air inlet, and then introduce the air flow into the hollow area of the stator through the air inlet pipe. Under the rotation of the rotor, the air inside the hollow area of the stator is evenly dispersed from the round holes on the upper cover of the stator and the grooves on the side wall surface into the kettle body, serving as the oxidant for the acid dissolution process of the lithium iron phosphate cathode black powder, oxidizing the iron element in the lithium iron phosphate cathode black powder into trivalent, leaching the lithium element in the lithium iron phosphate cathode black powder, and collecting the leached solution at the discharge port.

[0062] Compared with the prior art, the present utility model has at least the following beneficial effects:

[0063] (1) The oxidation reaction kettle proposed by the present utility model is provided with a stirrer including a stirring shaft, a stator, and a rotor inside the kettle body. The stator with a hollow cylindrical structure is fixedly arranged on the upper surface of the lower head at the bottom of the kettle body, the rotor is arranged in the hollow area surrounded by the stator and the lower head, and the air inlet arranged on the side of the kettle body is connected to the upper end of the stator inside the kettle body through the air inlet pipe. The gas introduced through the air inlet reaches the hollow area inside the stator through the air inlet pipe. During the rotation of the rotor sleeved inside the stator, a turbine dispersion effect is generated, and the gas introduced into the stator can be smoothly and evenly dispersed into the kettle body through several holes and grooves opened on the cylindrical structure of the stator. The material added to the kettle body through the feed port on the upper head above the kettle body can make more effective contact and adhesion with the gas bubbles dispersed inside the kettle body, promoting the mass transfer process of oxygen, and at the same time greatly increasing the contact area between oxygen and the material. Through the design of the positions and connection relationships of the various components of the oxidation reaction kettle, the oxidation rate in the oxidation reaction kettle can be increased, the dosage of the oxidant can be reduced, and the reaction cycle can be shortened.

[0064] (2) The combination of several round holes arranged in an array on the upper cover of the stator and several grooves arranged at equal intervals on the side wall surface in the oxidation reaction kettle provided by the present utility model, combined with the design of the blades in the rotor, can make the gas introduced into the hollow area inside the stator through the air inlet be more evenly and smoothly dispersed under the action of the rotor, and further improve the diffusion and gasification of the gas. Moreover, the design of the blades of the rotor perpendicular to the bottom bracket can, while ensuring the gas dispersion effect, reduce the cavitation phenomenon and stress concentration phenomenon of the gas flow on the blades. Description of the Drawings

[0065] Figure 1 It is a schematic diagram of the main cross-sectional structure of the oxidation reaction kettle provided by the present utility model.

[0066] Figure 2 It is a top view structural schematic diagram of the limit block in the oxidation reactor provided by the present utility model.

[0067] Figure 3 It is a top view structural schematic diagram of the rotor in the oxidation reactor provided by the present utility model.

[0068] Figure 4 It is a top view structural schematic diagram of the stator in the oxidation reactor provided by the present utility model.

[0069] Figure 5 It is an unfolded schematic diagram of the side of the stator part in the oxidation reactor provided by the present utility model.

[0070] Figure 6 is Figure 1 an enlarged top view structural schematic diagram of part A in

[0071] In the figure, 1 is the motor; 2 is the frame; 3 is the motor bracket; 4 is the upper head; 5 is the kettle body; 6 is the stirrer; 601 is the stirring shaft; 602 is the rotor; 602-1 is the annular side; 602-2 is the bottom bracket; 602-3 is the blade; 603 is the stator; 603-1 is the first round hole; 603-2 is the second round hole; 603-3 is the groove; 603-4 is the third round hole; 7 is the lower head; 8 is the air inlet; 801 is the first air inlet; 802 is the second air inlet; 9 is the discharge port; 10 is the limit block; 11 is the feed port; 12 is the functional port; 13 is the spare port; 14 is the oxidation blower. Specific embodiments

[0072] The technical solution of the present utility model will be further described below in conjunction with the drawings and through specific embodiments. However, the following examples are only simple examples of the present utility model and do not represent or limit the scope of the protection of the present utility model. The scope of protection of the present utility model shall be subject to the claims.

[0073] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model 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 a limitation of the present utility model. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0074] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "linkage" 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 an indirect connection through an intermediate medium, and it can be the communication inside two components. For the fields of electricity and communication, it can be a wired connection or a wireless connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0075] The lithium iron phosphate cathode black powder used in the following examples specifically comes from retired lithium iron phosphate batteries. The lithium iron phosphate cathode black powder includes 85 wt% of lithium iron phosphate, 7 wt% of conductive carbon black, 5 wt% of polyvinyl alcohol binder, 1 wt% of iron, 0.3 wt% of copper, and 1.7 wt% of aluminum.

[0076] Example 1

[0077] This example provides an oxidation reactor, and its schematic main view sectional structure is as Figure 1 shown, including a motor 1, a frame 2, a motor bracket 3, an upper head 4, a kettle body 5, a stirrer 6, a lower head 7, an air inlet 8, a discharge port 9, a limit block 10, a feed port 11, a functional port 12, a spare port 13, and an oxidation blower 14.

[0078] Among them, the upper head 4 and the lower head 7 are respectively arranged at the upper end and the lower end of the kettle body 5, and the upper head 4 and the lower head 7 are perpendicular to the side surface of the kettle body 5; the motor 1, the frame 2, and the motor bracket 3 are sequentially arranged in the middle area of the upper surface on the side of the upper head 4 away from the kettle body 5 from top to bottom. The motor bracket 3 is fixed to the upper surface on the side of the upper head 4 away from the kettle body 5 through a support ear. The frame 2 is located above the motor bracket 3 away from the upper head 4 and is connected to the motor bracket 3 by threads and fastened with bolts. The motor 1 is fixed above the frame 2, and the rotating shaft of the motor 1 is vertically installed on the motor bracket 3 through the frame 2 downward, and the rotating shaft of the motor 1 is connected to the upper end of the stirrer 6 through a coupling.

[0079] The stirrer 6 includes a stirring shaft 601, a rotor 602, and a stator 603. Specifically:

[0080] The lower end of the stirring shaft 601 is fixed to the upper surface of the lower head 7 through the limit block 10. The limit block 10 is located between the lower head 7 and the rotor 602. The top view schematic diagram of the limit block 10 is as Figure 2 shown. The stirring shaft 601 is located in the middle area of the kettle body 5 and is perpendicular to the surfaces of the lower head 7 and the upper head 4; the upper end of the stirring shaft 601 penetrates through the upper head 4 and extends to the outside of the kettle body 5 and is connected to the rotating shaft of the motor 1 through a coupling.

[0081] The rotor 602 includes an annular side surface 602-1, a bottom bracket 602-2, and 12 evenly arranged blades 602-3. The schematic top view structure is shown as follows. Figure 3 As shown, the rotor 602 is fixedly connected to the stirring shaft 601 through the bottom bracket 602-2. Its annular side surface 602-1 and blades 602-3 are both vertically fixed on the bottom bracket 602-2. The annular side surface 602-1 surrounds the outer periphery of the stirring shaft 601. The blades 602-3 are circumferentially arranged along the inner surface of the annular side surface 602-1. One end of the blade 602-3 is fixedly connected to the inner wall of the annular side surface 602-1, and the other end is spaced from the stirring shaft 601. The bottom bracket 602-2 of the rotor 602 is parallel to the lower head 7, and there is a gap between the rotor 602 and the lower head 7. The limit block 10 for fixing the stirring shaft 601 is located between the rotor 602 and the lower head 7. Taking the direction parallel to the surface of the lower head 7 as the horizontal direction, in the horizontal direction, the direction of the blade 602-3 forms an angle of 30° with the direction perpendicular to the tangent direction of the circle where the annular side surface 602-1 is located.

[0082] The stator 603 is a hollow cylindrical structure. The ratio of the outer diameter of the stator 603 to the inner diameter of the kettle body 5 is 1:3. The stator 603 includes an upper cover and a side wall surface connected to the outer edge on the side of the upper cover away from the stirring shaft 601. The schematic top view structure is shown as follows. Figure 4 As shown, the lower end of the side wall surface of the stator 603 is fixedly in contact with the upper surface of the lower head 7. The stator 603 is sleeved outside the rotor 602, and the rotor 602 is arranged in the hollow area formed by the stator 603 and the lower head 7. The upper cover of the stator 603 is perpendicular to the axial direction of the stirring shaft 601. The upper cover of the stator 603 is an annular structure with a first circular hole 603-1 opened in the middle. The stirring shaft 601 passes through the first circular hole 603-1 opened in the middle of the upper cover of the stator 603. The upper cover of the stator 603 is also provided with 32 second circular holes 603-2 arranged around the first circular hole 603-1. The second circular holes 603-2 are arranged in an array and penetrate through the upper cover of the stator 603. The second circular holes 603-2 are arranged radially with the center of the upper cover of the stator 603 as the center and are radially distributed from the inside to the outside. The connecting lines of the circles of the second circular holes 603-2 on the same radial length form 4 concentric circles on the upper cover. There are 8 second circular holes 603-2 arranged at equal angular intervals on the same concentric circle in the same radial length. The pore diameter of the second circular holes 603-2 is 2 mm, and the opening rate of the second circular holes 603-2 in the upper cover of the stator 603 is 10%. 14 equally spaced grooves 603-3 are opened on the cylindrical structure of the stator 603, and they are arranged at equal intervals along the circumference of the side wall surface of the stator 603. The direction of the grooves 603-3 is downward, that is, the depth direction of the grooves 603-3 extends towards the direction close to the upper surface of the lower head 7. The schematic structure diagram of a partial side expansion of the stator 603 is shown as follows. Figure 5 As shown.

[0083] The air inlet 8 in the oxidation reactor is arranged on the side surface of the reactor body 5. The number of air inlets 8 is two, including a first air inlet 801 and a second air inlet 802. The first air inlet 801 and the second air inlet 802 are arranged on two opposite side surfaces of the reactor body 5. The first air inlet 801 is connected to the upper cover of the stator 603 inside the reactor body 5 through a first air inlet pipe, and the second air inlet 802 is connected to the upper cover of the stator 603 inside the reactor body 5 through a second air inlet pipe. The tails of the first air inlet pipe and the second air inlet pipe near the stator 603 are respectively fixed and connected to two third round holes 603-4 with close distances in the upper cover of the stator 603. Both the first air inlet 801 and the second air inlet 802 are connected to the oxidation blower 14 arranged outside the reactor body 5; the discharge port 9 is fixed and connected to the bottom of the side surface of the reactor body 5; the feed inlet 11, the function port 12 and the spare port 13 in the oxidation reactor are all arranged on the upper head 4 above the reactor body 5 and on one side of the frame 2. The feed inlet 11, the function port 12 and the spare port 13 are respectively connected to the upper head 4 from top to bottom through a feed pipe, a function pipe and a spare pipe and extend into the reactor body 5. The feed pipe, the function pipe and the spare pipe are sequentially fixed and connected to the upper head 4 from top to bottom through the same flange and extend into the reactor body 5. The top view structural schematic diagram of the distribution of the feed inlet 11, the function port 12 and the spare port 13 on the flange is as Figure 6 .

[0084] This embodiment also provides a production process for iron oxide red that can be used based on the above oxidation reactor. The specific process includes the following steps:

[0085] (A) Add ammonia water and ferrous sulfate into the reactor body 5 from the feed inlet 11 above the reactor body 5 to form a mixed solution. Regulate the addition amounts of ammonia water and ferrous sulfate so that the pH of the mixed solution is 9. Turn on the motor 1 to drive the rotor 602 connected to the stirring shaft 601 to rotate at a speed of 500 revolutions per minute. At the same time, turn on the oxidation blower 14 to introduce air into the air inlet 8, and then introduce the air flow into the hollow area of the stator 603 through the air inlet pipe. Under the rotation of the rotor 602, the air inside the hollow area of the stator 603 is evenly dispersed into the reactor body 5 from the second round hole 603-2 on the upper cover of the stator 603 and the groove 603-3 on the side wall surface, and the mixed solution inside the reactor body 5 is oxidized to prepare ferric oxide seeds.

[0086] (B) Continue to add ammonia water and ferrous sulfate into the reactor body 5 through the feed inlet 11, keep the pH of the mixed solution inside the reactor body 5 at 9, and at the same time continue to introduce air into the air inlet 8 by using the oxidation blower 14. The air enters the hollow area of the stator 603 through the air inlet pipe. The rotor 602 rotates continuously at a speed of 500 revolutions per minute, and disperses the air evenly into the reactor body 5 from the second round hole 603-2 on the upper cover of the stator 603 and the groove 603-3 on the side wall surface. Under the oxidation condition of the air, the mixed product of ferrous sulfate and ammonia water continues to generate ferric oxide on the basis of the ferric oxide seeds obtained in step (A). At the same time, the generated sulfuric acid is neutralized by the added ammonia water to obtain ferric oxide nuclei.

[0087] (C) Continue to perform step (B). The ferric oxide nuclei obtained in step (B) gradually grow until iron red is formed, and the iron red is collected through the discharge port 9.

[0088] Comparative Example 1

[0089] The difference between this comparative example and Example 1 is only that: the oxidation reactor provided in this comparative example omits the stator 603, and directly introduces the air introduced from the air inlet 8 into the reactor body 5. The rest of the content is the same as that of Example 1.

[0090] Comparative Example 2

[0091] The difference between this comparative example and Example 1 is only that: the oxidation reactor provided in this comparative example omits the rotor 602. The rest of the content is the same as that of Example 1.

[0092] For the oxidation efficiency and the purity of the iron red obtained in the iron red preparation process of the oxidation reactors provided in the above Example 1 and Comparative Examples 1-2, tests were carried out and the reaction time was recorded. The calculation formula for the oxidation efficiency is: the percentage of the content of the actually generated iron red to the content of the iron red prepared theoretically. The test results are shown in Table 1.

[0093] Table 1

[0094]

[0095] It can be seen from Table 1 that:

[0096] Through the design of various components in the oxidation reactor of the present utility model, the gas introduced from the air inlet reaches the hollow area inside the stator through the air inlet pipe. During the rotation of the rotor sleeved inside the stator, a turbine dispersion effect is generated. The gas introduced into the stator can be smoothly and evenly dispersed into the reactor body through the round holes and grooves opened on the stator, and fully contact with the materials above the reactor body, thereby improving the dispersion, gasification and mass transfer effects of the gas used for oxidation reaction, and then quickly, evenly and smoothly realizing the air oxidation process flow. It realizes the integration of seed preparation and oxidation reaction in the iron red preparation process under the same equipment conditions, simplifies the process production, optimizes the operation environment, and meets the requirements of the iron red production for the equipment. If the stator is missing in the oxidation reactor, it will lead to the inability to form a negative pressure cavity, resulting in uneven gas dispersion and affecting the reaction effect; if the rotor is missing in the oxidation reactor, it will lead to a significant decrease in both the oxidation efficiency and the purity of the obtained iron red.

[0097] Example 2

[0098] This example uses the same oxidation reactor as Example 1, and the difference is only that: this example uses the oxidation reactor for the oxidation in the recovery production of lithium iron phosphate waste. The specific process includes the following steps:

[0099] Put the lithium iron phosphate cathode black powder into the reactor body 5, introduce hydrochloric acid solution from the feed inlet 11 to dissolve the lithium iron phosphate cathode black powder in the reactor body 5, turn on the motor 1 above the reactor body 5 to drive the stirring shaft 601 and the rotor 602 connected to the stirring shaft 601 to rotate at a speed of 900 revolutions per minute. At the same time, turn on the oxidation blower 14 to introduce air into the air inlet 8, and then introduce the air flow into the hollow area of the stator 603 through the air inlet pipe. Under the rotation of the rotor 602, the air inside the hollow area of the stator 603 is evenly dispersed into the reactor body 5 from the second round hole 603-2 on the upper cover of the stator 603 and the groove 603-3 on the side wall surface, serving as the oxidant for the acid dissolution process of the lithium iron phosphate cathode black powder, oxidizing the iron element in the lithium iron phosphate cathode black powder into trivalent, and leaching out the lithium element in the lithium iron phosphate cathode black powder, and collecting the leached solution at the discharge outlet 9.

[0100] Comparative Example 3

[0101] The difference between this comparative example and Example 2 is only that: the oxidation reactor provided in this comparative example omits the stator 603, and directly introduces the air introduced from the air inlet 8 into the reactor body 5. The rest of the content is the same as that of Example 2.

[0102] Comparative Example 4

[0103] The difference between this comparative example and Example 2 is only that: the oxidation reactor provided in this comparative example omits the rotor 602. The rest of the content is the same as that of Example 2.

[0104] The iron oxidation efficiency, acid consumption, and lithium leaching rate of the oxidation reactors provided in the above-mentioned Example 2 and Comparative Examples 3-4 were detected during the recovery production of lithium iron phosphate waste. Among them, the iron oxidation efficiency is the percentage of the content of trivalent iron actually obtained to the content of trivalent iron theoretically obtained, and the acid consumption is the molar amount of hydrochloric acid required per mole of divalent iron. The test results are shown in Table 2.

[0105] Table 2

[0106]

[0107] As can be seen from Table 2:

[0108] Through the settings of the positional relationships and connection relationships of each component, the oxidation reactor provided in this embodiment can meet the oxidation reaction during the acid dissolution process of waste lithium iron phosphate cathode black powder, selectively oxidize lithium using air as an oxidant, oxidize iron elements in-situ to trivalent without destroying the crystal structure of lithium iron phosphate, enabling it to occupy some lattice sites of lithium, resulting in the leaching of lithium elements and their dissolution in the liquid phase. Moreover, the introduced air can be quickly, evenly, and smoothly dispersed inside the reactor body under the action of the stator and rotor, and can be more fully mixed with the materials inside the reactor body, reducing the consumption of acid and oxidant during the recovery process of waste lithium iron phosphate cathode black powder, achieving the purpose of cost reduction and efficiency improvement. If the stator is missing in the oxidation reactor, a negative pressure cavity cannot be formed, resulting in uneven gas dispersion and affecting the reaction effect; if the rotor is missing in the oxidation reactor, the acid consumption will increase, the iron oxidation efficiency will decrease, and the leaching rate of trivalent lithium will decline.

[0109] In summary, for the oxidation reactor proposed by the present utility model, a stirrer including a stirring shaft, a stator, and a rotor is arranged inside the reactor body. The stator with a hollow cylindrical structure is fixedly arranged on the upper surface of the lower head at the bottom of the reactor body. The rotor is arranged in the hollow area surrounded by the stator and the lower head. The air inlet arranged on the side of the reactor body is connected to the inside of the reactor body through an air inlet pipe and is connected to the upper end of the stator inside the reactor body. The gas introduced through the air inlet reaches the hollow area inside the stator through the air inlet pipe. During the rotation of the rotor sleeved inside the stator, a turbine dispersion effect is generated. The gas introduced into the stator can be smoothly and evenly dispersed into the reactor body through a plurality of holes and grooves opened on the cylindrical structure of the stator. The materials added to the reactor body through the feed inlet arranged on the upper head above the reactor body can make more effective contact and adhesion with the gas bubbles dispersed inside the reactor body, promoting the mass transfer process of oxygen and greatly increasing the contact area between oxygen and the materials. Through the design of the positions and connection relationships of each component of the oxidation reactor, the oxidation rate in the reactor can be increased and the reaction cycle can be shortened.

[0110] The applicant declares that the above is only the specific implementation mode of the present utility model, but the protection scope of the present utility model is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present utility model fall within the protection scope and the public scope of the present utility model.

Claims

1. An oxidation reactor, characterized in that: The oxidation reaction kettle comprises a kettle body, an upper head and a lower head located at the upper and lower ends of the kettle body, a feed inlet is arranged on the upper head, and a discharge port and an air inlet are arranged on the side of the kettle body; An agitator is arranged inside the kettle body, and the agitator includes a stirring shaft, a rotor and a stator. The rotor is connected to the stirring shaft, and the stator is a hollow cylindrical structure, which is sleeved on the outside of the rotor. The lower end of the stator is in fixed contact with the upper surface of the lower head, and the upper end of the stator is connected to the air inlet through an air intake pipe; a plurality of holes and a plurality of grooves are opened on the stator.

2. The oxidation reactor according to claim 1, characterized in that: The lower end of the stirring shaft is fixed to the upper surface of the lower head through a limit block; The limit block is located between the lower head and the rotor; The stirring shaft is located in the middle area of ​​the kettle body and is perpendicular to the surfaces of the lower head and the upper head; The upper end of the stirring shaft passes through the upper head and extends to the outside of the kettle body.

3. The oxidation reactor according to claim 2, characterized in that: The oxidation reaction kettle also includes an electric drive device located outside the kettle body; The electric drive device comprises a motor bracket, a frame and a motor arranged in sequence from bottom to top, and the electric drive device is fixed to the middle area of ​​the upper surface of the upper head away from the kettle body through the motor bracket; The motor bracket is fixed to the upper head via support ears; The frame is located on a side of the motor support away from the upper head, and is fixedly connected to the motor support via a fixing component; The motor is fixed above the frame, the rotating shaft of the motor is vertically installed on the motor bracket through the frame, and the rotating shaft of the motor is connected to the upper end of the stirring shaft through a coupling.

4. The oxidation reactor according to claim 2, characterized in that: The stator comprises an upper cover and a side wall surface connected to the outer edge of the upper cover away from the stirring shaft; The upper cover of the stator is arranged perpendicular to the axial direction of the stirring shaft, and the upper cover of the stator is an annular structure with a hole in the middle; The stirring shaft passes through the middle opening of the upper cover of the stator; The plurality of holes opened on the stator are circular holes, and the circular holes are arranged in an array and penetrate the upper cover of the stator; The circular holes are arranged radially with the center of the upper cover as the center, and are distributed radially from the inside to the outside, and the lines connecting the centers of the circular holes on the same radial length form a plurality of concentric circles on the upper cover; The circular holes on the concentric circles of the same radial length are arranged at equal angle intervals; The number of the concentric circles is 4 or more; The pore diameter of the circular hole is greater than 2 mm; The opening rate of the upper cover of the stator is more than 10%.

5. The oxidation reactor according to claim 4, characterized in that: A plurality of grooves provided on the stator are arranged at intervals along the circumferential direction of the side wall surface of the stator; The grooves are arranged at equal intervals; The depth direction of the groove extends toward the direction close to the upper surface of the lower head.

6. The oxidation reactor according to claim 1, characterized in that: The rotor comprises an annular side surface, a bottom support and a plurality of blades, wherein the annular side surface and the blades are both vertically fixed on the bottom support; The annular side surface is arranged around the outer periphery of the stirring shaft, the plurality of blades are arranged circumferentially along the inner surface of the annular side surface, one end of the blade is fixedly connected to the inner wall of the annular side surface, and the other end is arranged at an interval with the stirring shaft; The bottom support of the rotor is parallel to the lower head, and there is a gap between the rotor and the lower head; Taking the direction parallel to the surface of the lower head as the horizontal direction, in the horizontal direction, the direction of the blade is 30-60 degrees with the direction perpendicular to the tangent direction of the circle where the annular side surface is located.

7. The oxidation reactor according to claim 1, characterized in that: The oxidation reactor also includes a coil heat exchanger; The coil heat exchanger is arranged in a spiral shape on the side inner wall of the kettle body.

8. The oxidation reactor according to claim 1, characterized in that: The oxidation reaction kettle also includes an oxidation fan externally connected to the air inlet.

9. The oxidation reactor according to claim 3, characterized in that: The oxidation reaction kettle is provided with a functional port, which is connected to the upper head from top to bottom through a functional pipeline and extends to the interior of the kettle body; The oxidation reaction kettle is also provided with a spare port, which is connected to the upper head from top to bottom through a spare pipeline and extends to the interior of the kettle body; The feed port is connected to the upper head from top to bottom through a feed pipe and extends to the interior of the kettle body.

10. The oxidation reactor according to claim 9, characterized in that: The feed port and the connected feed pipeline, the functional port and the connected functional pipeline, and the spare port and the connected spare pipeline are fixed by the same fixing component and are connected to the upper head and extend to the interior of the kettle body.

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