A reaction apparatus for improving the yield of cryolite

Abstract

The utility model relates to a kind of reaction equipment of improving cryolite yield, including crystallization kettle, the inside of crystallization kettle is provided with fixed stirring part and rotary stirring part, the fixed stirring part is installed in crystallization kettle top, the rotary stirring part is rotated by drive assembly from the outer circumferential side of fixed stirring part and below and carries out rotary stirring;The inside wall of the crystallization kettle is vertically provided with stirring baffle.The drive assembly includes the stirring transmission shaft that is vertically through the top of crystallization kettle, the stirring transmission shaft is rotated by stirring motor driven installation above crystallization kettle, and the end of stirring transmission shaft that extends into the inside of crystallization kettle is connected with rotary stirring part.The utility model design is reasonable, using fixed stirring, rotary stirring and stirring baffle combination, realize more uniform mixing, shorten cryolite reaction time, improve fluorine ion conversion rate, improve cryolite yield, while reduce cryolite crystal grain size, improve cryolite quality.

Description

Technical Field

[0001] This utility model relates to a reaction device for improving cryolite yield. Background Technology

[0002] In the industrial production of cryolite (Na3AlF6), the crystallization vessel is the core equipment for controlling crystallization quality. Traditional crystallization vessels employ a single-layer stirring structure with a central shaft (such as a straight-blade turbine or propeller), using mechanical rotation to drive the mixing of materials within the vessel to achieve crystallization from a supersaturated solution. However, this method has several problems in practical applications: Firstly, the stirrer struggles to achieve full coverage of the flow field within the vessel, easily creating dead zones and concentration gradients, leading to uneven local supersaturation. Nucleation occurs too quickly in some areas while crystallization lags behind in others, resulting in a wide crystal size distribution and a high proportion of fine crystals. Secondly, at specific rotational speeds, a strong central low-pressure vortex zone is formed. The rotating fluid moves towards the vessel wall under centrifugal force, creating negative pressure in the central area and a "funnel-shaped" depression on the liquid surface. Crystals are thrown to the vessel wall area under centrifugal force, and the central vortex zone forms a particle settling channel due to insufficient flow velocity. Utility Model Content

[0003] This invention addresses the problems existing in the prior art, namely, the technical problem to be solved by this invention is to provide a reaction device that improves cryolite yield.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is: a reaction device for improving cryolite yield, comprising a crystallization vessel, wherein a fixed stirring element and a rotating stirring element are provided inside the crystallization vessel, the fixed stirring element is installed on the top of the crystallization vessel, and the rotating stirring element is driven by a drive assembly to rotate and stir from the outer periphery and below of the fixed stirring element; a stirring baffle is vertically provided on the inner wall of the crystallization vessel.

[0005] Furthermore, the drive assembly includes a stirring drive shaft extending vertically through the top of the crystallization vessel. The stirring drive shaft is driven to rotate by a stirring motor mounted above the crystallization vessel, and one end of the stirring drive shaft extending into the interior of the crystallization vessel is connected to a rotating stirring element.

[0006] Furthermore, the fixed stirring component includes a fixed sleeve coaxially sleeved on the stirring drive shaft. The upper end of the fixed sleeve is connected to the top of the crystallization vessel, and a pair of stirring plates are symmetrically arranged on the outer wall of the lower end of the fixed sleeve.

[0007] Furthermore, the rotating stirring component includes a stirring shaft coaxially arranged with the stirring drive shaft. The upper end of the stirring shaft extends into the fixed sleeve and is connected to the lower end of the stirring drive shaft through a coupling. A pair of symmetrically distributed stirring rods are provided at the lower end of the stirring shaft.

[0008] Furthermore, the stirring rod includes a vertical section and an inclined section arranged sequentially from top to bottom. The inclined section is located below the stirring plate, with its lower end connected to the stirring shaft and its upper end connected to the lower end of the vertical section. The vertical section is located on the outer periphery of the stirring plate.

[0009] Furthermore, the bottom of the crystallization vessel is provided with a discharge port, and an air blowing discharge pipe is vertically arranged inside the crystallization vessel at the end away from the stirring baffle. The upper end of the air blowing discharge pipe penetrates through the top of the crystallization vessel and the upper port is designed to facilitate gas input, while the lower port of the air blowing discharge pipe faces the discharge port.

[0010] Furthermore, the lower part of the crystallization vessel is inverted cone shape, and the lower end of the air blowing outlet pipe is provided with an inclined bending section, which is parallel to the cone surface of the lower part of the crystallization vessel.

[0011] Furthermore, a detection tube is vertically installed inside the crystallizer at the end away from the stirring baffle. The bottom port of the detection tube is connected to the inside of the crystallizer, and the upper end of the detection tube extends out of the top of the crystallizer, with the top port serving as a thermometer mounting port.

[0012] Furthermore, the top of the crystallization vessel is provided with a feed inlet and a manhole.

[0013] Furthermore, two level gauge mounting ports are provided on one side of the crystallization vessel, one above the other, and two sampling and discharge ports are provided on the other side of the crystallization vessel, one above the other.

[0014] Compared with the prior art, the present invention has the following effects: The present invention is reasonably designed and adopts a combination of fixed stirring, rotary stirring and stirring baffle to achieve more uniform mixing, shorten the cryolite reaction time, improve the fluoride ion conversion rate, improve the cryolite yield, and at the same time reduce the size of cryolite crystals and improve the quality of cryolite. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model.

[0016] In the picture: 1-Crystallization vessel; 2-Fixed stirring component; 3-Rotating stirring component; 4-Stirring baffle; 5-Stirring drive shaft; 6-Stirring motor; 7-Fixed sleeve; 8-Stirring plate; 9-Stirring shaft; 10-Coupling; 11-Stirring rod; 111-Vertical section; 112-Inclined section; 12-Detection tube; 13-Thermometer mounting port; 14-Feed inlet; 15-Manhole; 16-Level gauge mounting port; 17-Sampling outlet; 18-Steam port; 19-Outlet; 20-Air blowing outlet pipe; 201-Inclined bending section. Detailed Implementation

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0018] In the description of this utility model, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0019] like Figure 1 As shown, this utility model discloses a reaction device for improving cryolite yield, comprising a crystallization vessel 1. The crystallization vessel 1 is internally equipped with a fixed stirring element 2 and a rotating stirring element 3, distributed vertically. The fixed stirring element 2 is mounted on the top of the crystallization vessel 1, and the rotating stirring element 3 is driven by a drive assembly to rotate and stir from the outer periphery and below of the fixed stirring element 2. A stirring baffle 4 is vertically arranged on the inner wall of the crystallization vessel 1. The stirring method combines fixed stirring and rotating stirring, along with the stirring baffle, breaking the vortex (whirling) phenomenon generated by the traditional rotating impeller. It effectively transforms the rotating tangential flow into radial and axial flow, which greatly enhances the turbulence intensity. This allows for more uniform mixing of the materials (solution, crystals, additives) throughout the entire volume of the crystallization vessel, especially in areas near the vessel wall, bottom, and top. This avoids the mixing dead zones and concentration / temperature gradients that may exist in traditional stirring, resulting in uniform mixing, preventing scaling, controlling crystal particle size distribution, and improving heat and mass transfer efficiency.

[0020] In this embodiment, the driving component includes a stirring drive shaft 5 that extends vertically through the top of the crystallization vessel 1. The stirring drive shaft 5 is driven to rotate by a stirring motor 6 installed above the crystallization vessel 1. One end of the stirring drive shaft 5 that extends into the crystallization vessel 1 is connected to a rotating stirring element 3. The stirring drive shaft rotates under the drive of the stirring motor, and the rotating stirring element rotates synchronously when the stirring drive shaft rotates.

[0021] In this embodiment, the fixed stirring component 2 includes a fixed sleeve 7 coaxially sleeved on the stirring drive shaft 5. The upper end of the fixed sleeve 7 is connected to the top of the crystallization vessel 1. A pair of stirring plates 8 are symmetrically arranged on the outer side wall of the lower end of the fixed sleeve 7. The stirring plates 8 are arranged vertically and are arranged along the radial direction of the fixed sleeve 7.

[0022] In this embodiment, the rotating stirring component 3 includes a stirring shaft 9 coaxially arranged with the stirring drive shaft 5. The stirring shaft is located below the stirring drive shaft. The upper end of the stirring shaft 9 extends into the fixed sleeve 7 and is connected to the lower end of the stirring drive shaft 5 via a coupling 10. A pair of symmetrically distributed stirring rods 11 are provided at the lower end of the stirring shaft 9. During operation, the stirring drive shaft drives the stirring shaft to rotate, and the stirring shaft drives the pair of stirring rods to rotate.

[0023] In this embodiment, each stirring rod 11 includes a vertical section 111 and an inclined section 112 arranged sequentially from top to bottom. The inclined section 112 is located below the stirring plate 8. The lower end of the inclined section 112 is connected to the stirring shaft 9, and the upper end is connected to the lower end of the vertical section 111. The vertical section 111 is located on the outer periphery of the stirring plate 8. When the stirring rod rotates under the drive of the stirring shaft, the vertical end of the stirring rod rotates and stirs from the outer periphery of the fixed stirring element, and the inclined section of the stirring rod rotates and stirs from below the fixed stirring element.

[0024] In this embodiment, the bottom of the crystallization vessel 1 is provided with a discharge port 19. Inside the crystallization vessel 1, at the end furthest from the stirring baffle 4, a blow-out discharge pipe 20 is vertically arranged. The upper end of the blow-out discharge pipe 20 penetrates the top of the crystallization vessel 1, with its upper port facilitating gas input. The lower port of the blow-out discharge pipe 20 faces the discharge port 19. During operation, high-pressure gas is input through the upper port of the blow-out discharge pipe, and the high-pressure gas inside the pipe is output from the lower port to the discharge port, facilitating the blowing of the material inside the crystallization vessel out of the discharge port after stirring. Using a blow-out discharge method improves discharge efficiency and reduces clogging.

[0025] In this embodiment, the upper part of the crystallization vessel 1 is convex arc-shaped, and the lower part is inverted cone-shaped. In order to adapt to the inverted cone-shaped structure of the lower part of the crystallization vessel, the lower end of the air blowing outlet pipe 20 is provided with an inclined bending section 201, which is parallel to the cone surface of the lower part of the crystallization vessel 1.

[0026] In this embodiment, a detection tube 12 is vertically installed inside the crystallization vessel 1 at the end furthest from the stirring baffle 4. The bottom port of the detection tube 12 is connected to the inside of the crystallization vessel 1, and the upper end of the detection tube 12 extends out of the top of the crystallization vessel, with the top port serving as a thermometer mounting port 13. The thermometer detects the temperature of the material entering the detection tube, thereby enabling the detection of the temperature inside the crystallization vessel.

[0027] In this embodiment, the top of the crystallization vessel 1 is provided with a feed inlet 14 and a manhole 15. The feed inlet facilitates feeding materials into the crystallization vessel, and the manhole facilitates personnel to enter the interior for maintenance and repair.

[0028] In this embodiment, two upper and lower liquid level gauge mounting ports 16 are provided on one side of the crystallization vessel 1, and liquid level gauges are installed in the liquid level gauge mounting ports to facilitate the detection of liquid level in the crystallization vessel; two upper and lower sampling outlet ports 17 are provided on the other side of the crystallization vessel 1, and samples are taken through the sampling outlet ports.

[0029] In this embodiment, a heating jacket is provided on the outside of the crystallization vessel 1, and a steam port 18 is provided on the side of the heating jacket. The steam port is equipped with a steam valve, and the crystallization vessel is heated by introducing steam.

[0030] Specific implementation process: Add the prepared fluoride wastewater slurry to the crystallization reactor. Stop feeding when the primary crystallizer level reaches 70-80%. Control the steam valve opening to maintain the primary crystallizer temperature at 50-60℃. During the process, based on the pH readings from the primary crystallizer, add alkaline materials (sodium hydroxide / potassium hydroxide) to the crystallizer, maintaining the pH between 3.5 and 5, and allow the reaction to proceed for 6-12 hours. During the reaction, keep the fixed agitator stationary while rotating the agitator at a low speed of 20-60 rpm to promote mass transfer and prevent crystal breakage. After the reaction, discharge the solid-liquid mixture from the primary crystallizer through a pipeline to a centrifuge for solid-liquid separation.

[0031] The advantages of this utility model are: (1) shortening the cryolite reaction time and increasing the cryolite crystal formation rate; (2) reducing the size of cryolite crystal particles, making the crystal particles uniform and improving the quality of cryolite; (3) improving the fluoride ion conversion rate, resulting in better reaction effect and higher fluoride removal efficiency.

[0032] If this utility model discloses or relates to mutually fixedly connected parts or structural components, then, unless otherwise stated, a fixed connection can be understood as: a detachable fixed connection (e.g., using bolts or screws), or a non-detachable fixed connection (e.g., riveting, welding). Of course, mutually fixed connections can also be replaced by an integral structure (e.g., manufactured using a casting process) (except where it is obviously impossible to use an integral forming process).

[0033] In addition, unless otherwise stated, the terms used to indicate positional relationships or shapes in any of the technical solutions disclosed in this utility model above include states or shapes that are similar to, close to, or approximate with them.

[0034] Any component provided by this utility model can be assembled from multiple individual components, or it can be a single component manufactured by a one-piece molding process.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it; although the utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of this utility model or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solution of this utility model, and all such modifications and substitutions should be covered within the scope of the technical solution claimed by this utility model.

Claims

1. A reaction apparatus for improving cryolite yield, comprising a crystallization vessel, characterized in that: The crystallization vessel is equipped with a fixed stirring component and a rotating stirring component. The fixed stirring component is installed on the top of the crystallization vessel, and the rotating stirring component is driven by a drive assembly to rotate and stir from the outer periphery and below of the fixed stirring component. The inner wall of the crystallization vessel is vertically equipped with stirring baffles. The drive assembly includes a stirring drive shaft that extends vertically through the top of the crystallization vessel. The stirring drive shaft is driven to rotate by a stirring motor installed above the crystallization vessel. One end of the stirring drive shaft that extends into the interior of the crystallization vessel is connected to a rotating stirring element. The fixed stirring component includes a fixed sleeve coaxially sleeved on the stirring drive shaft. The upper end of the fixed sleeve is connected to the top of the crystallization vessel, and a pair of stirring plates are symmetrically arranged on the outer wall of the lower end of the fixed sleeve. The rotating stirring component includes a stirring shaft coaxially arranged with the stirring drive shaft. The upper end of the stirring shaft extends into the fixed sleeve and is connected to the lower end of the stirring drive shaft through a coupling. A pair of symmetrically distributed stirring rods are provided at the lower end of the stirring shaft.

2. The reaction equipment for increasing cryolite yield according to claim 1, characterized in that: The stirring rod includes a vertical section and an inclined section arranged sequentially from top to bottom. The inclined section is located below the stirring plate. The lower end of the inclined section is connected to the stirring shaft, and the upper end is connected to the lower end of the vertical section. The vertical section is located on the outer periphery of the stirring plate.

3. The reaction equipment for increasing cryolite yield according to claim 1, characterized in that: The bottom of the crystallization vessel is provided with a discharge port. Inside the crystallization vessel, at the end away from the stirring baffle, a blowing discharge pipe is vertically arranged. The upper end of the blowing discharge pipe passes through the top of the crystallization vessel and the upper port is designed to facilitate gas input. The lower port of the blowing discharge pipe faces the discharge port.

4. The reaction equipment for increasing cryolite yield according to claim 3, characterized in that: The lower part of the crystallization vessel is inverted cone shape, and the lower end of the air blowing outlet pipe is provided with an inclined bending section, which is parallel to the cone surface of the lower part of the crystallization vessel.

5. The reaction apparatus for increasing cryolite yield according to claim 1, characterized in that: Inside the crystallizer, a detection tube is vertically installed at the end away from the stirring baffle. The bottom port of the detection tube is connected to the inside of the crystallizer, and the upper end of the detection tube extends out of the top of the crystallizer, with the top port serving as a thermometer mounting port.

6. The reaction apparatus for increasing cryolite yield according to claim 1, characterized in that: The top of the crystallization vessel is provided with a feed inlet and a manhole.

7. The reaction apparatus for increasing cryolite yield according to claim 1, characterized in that: Two level gauge mounting ports, one above the other, are provided on one side of the crystallization vessel, and two sampling and discharge ports, one above the other, are provided on the other side of the crystallization vessel.

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