A continuous gradient addition device for extractant in a lanthanum-cerium separation process

Abstract

This utility model discloses a continuous gradient addition device for extractant in a lanthanum-cerium separation process, comprising several tanks. Each tank has a feed pipe on its upper surface, a conduit connecting to adjacent tanks on its side surface, and a discharge pipe on the end of the tank's side surface. Centrifugal pumps are installed on both the discharge pipe and the conduit. A low-speed stirring device and a spraying device are also installed on the tanks. Multiple tanks are cascaded via conduits, and the flow rate between stages is dynamically controlled by the centrifugal pumps, causing the extractant concentration to decrease gradually, eliminating concentration jumps, and improving the lanthanum-cerium separation coefficient. The low-speed stirring device inside the tank improves extraction efficiency while preventing blockage of the tank bottom and pipes due to easy crystallization of cerium sulfate, reducing the frequency of downtime cleaning and improving work efficiency. The spraying device enables online cleaning after shutdown, improving residual liquid discharge rate and preventing cross-contamination between batches.

Description

Technical Field

[0001] This utility model relates to the field of lanthanum and cerium separation technology, specifically to a device for continuous gradient addition of extractant in a lanthanum and cerium separation process. Background Technology

[0002] Lanthanum and cerium are a mixture of rare earth elements, composed of lanthanum and cerium. Lanthanum and cerium possess excellent chemical stability and spectral properties, and are widely used in industries such as electronics, lighting, and glass. For example, in the electronics industry, lanthanum and cerium can be used to produce high-efficiency LEDs, solar panels, and displays.

[0003] In lanthanum-cerium solvent extraction and separation processes, the extractant (such as P507) is typically added to the mixing and clarification tank in stages with a stepped concentration. Existing lanthanum-cerium solvent extraction and separation devices are prone to abrupt changes in the organic phase concentration within the extraction tank during staged addition, leading to lanthanum-cerium co-extraction and a decrease in the separation coefficient. Simultaneously, cerium sulfate in high-acidity feed solutions (pH < 1) easily crystallizes, and traditional storage tanks lack agitation, resulting in a high rate of blockage at the tank bottom and in pipelines, requiring frequent shutdowns for cleaning and impacting overall efficiency. Therefore, we propose a continuous gradient addition device for the extractant in the lanthanum-cerium separation process. Utility Model Content

[0004] The technical problem to be solved by this utility model is to overcome the existing defects and provide a continuous gradient addition device for extractant in the lanthanum-cerium separation process. Multiple tanks are cascaded through conduits and the flow rate between stages is dynamically controlled by a centrifugal pump, so that the extractant concentration decreases step by step, eliminating concentration jumps and improving the lanthanum-cerium separation coefficient. This can effectively solve the problems in the background technology.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a continuous gradient addition device for extractant in a lanthanum-cerium separation process, comprising several tanks, wherein a feed pipe is provided on the upper surface of the tank, a conduit connected to an adjacent tank is provided on the side surface of the tank, and a discharge pipe is provided on the side surface of the tank at the end, and a centrifugal pump is provided on both the discharge pipe and the conduit; a low-speed stirring device and a spraying device are provided on the tank.

[0006] As a preferred technical solution of this utility model, the low-speed stirring device includes a geared motor installed at the center of the upper surface of the tank. The output shaft of the geared motor passes through the inside of the tank and is connected to the rotating shaft through a coupling. A number of stirring blades are evenly arranged on the circumferential surface of the rotating shaft.

[0007] As a preferred embodiment of this utility model, the lower part of the tank is conical, and the bottom end of the rotating shaft is provided with a conical spiral stirring paddle corresponding to the lower part of the tank.

[0008] As a preferred technical solution of this utility model, the spraying device includes a spray liquid inlet pipe disposed on the upper side of the tank body. The spray liquid inlet pipe passes through the tank body and communicates with the annular spray pipe. A plurality of connecting rods connected to the inner wall of the tank body are evenly disposed on the upper surface of the annular spray pipe, and a plurality of spray heads are evenly disposed on the lower surface of the annular spray pipe.

[0009] As a preferred embodiment of this utility model, two annular spray pipes are provided, which are concentrically arranged and connected by a connecting pipe.

[0010] As a preferred embodiment of this utility model, the outlet of the spray head on the annular spray pipe is inclined to the lower outer part.

[0011] As a preferred embodiment of this utility model, a drain pipe is provided at the bottom of the tank, and a drain valve is installed on the drain pipe.

[0012] As a preferred embodiment of this invention, a transparent observation window is provided on the side surface of the tank.

[0013] Compared with the prior art, the beneficial effects of this utility model are as follows: multiple tanks are cascaded through conduits, and the flow rate between stages is dynamically controlled by a centrifugal pump, so that the concentration of the extractant decreases stepwise, eliminating concentration jumps and improving the lanthanum-cerium separation coefficient; a low-speed stirring device is installed in the tank to improve extraction efficiency while avoiding blockage of the tank bottom and pipes caused by easy crystallization of cerium sulfate, reducing the frequency of shutdown cleaning and improving work efficiency; the spray device can realize online cleaning after shutdown, improve the residual liquid discharge rate, and eliminate cross-contamination between batches. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of this utility model;

[0015] Figure 2 This is a schematic diagram of the internal structure of a single tank of this utility model;

[0016] Figure 3 This utility model Figure 2 A side view structural diagram.

[0017] In the diagram: 1 Tank body, 2 Feed pipe, 3 Gear motor, 31 Rotary shaft, 32 Agitator blade, 33 Spiral agitator, 4 Spray liquid inlet pipe, 41 Annular spray pipe, 42 Connecting rod, 43 Spray head, 5 Drain pipe, 51 Drain valve, 6 Guide pipe, 7 Centrifugal pump, 8 Discharge pipe, 9 Observation window. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0019] Please see Figure 1-3 This utility model provides a technical solution: a continuous gradient addition device for extractant in a lanthanum-cerium separation process, comprising several tanks 1, which are fixed to the ground or a workbench by supports, etc. An inlet pipe 2 is provided on the upper surface of each tank 1, and a conduit 6 connecting to adjacent tanks 1 is provided on the side surface of each tank 1. An outlet pipe 8 is provided on the side surface of the tank 1 at the end. A centrifugal pump 7 and a pneumatic butterfly valve are provided on both the outlet pipe 8 and the conduit 6. Multiple tanks 1 are cascaded through the conduit 6, and the interstage flow rate is dynamically controlled by the centrifugal pump 7 and the pneumatic butterfly valve, causing the extractant concentration to decrease stepwise (e.g., 100%→80%→60%→40%→20%), eliminating concentration jumps and improving the lanthanum-cerium separation coefficient.

[0020] and spraying equipment.

[0021] In a preferred embodiment, a low-speed stirring device is provided on the tank body 1. The presence of a low-speed stirring device inside the tank improves extraction efficiency while avoiding blockage of the tank bottom and pipes caused by the easy crystallization of cerium sulfate, reducing the frequency of downtime for cleaning and improving work efficiency.

[0022] Specifically, the low-speed stirring device includes a geared motor 3 installed at the center of the upper surface of the tank 1. The output shaft of the geared motor 3 passes into the interior of the tank 1 and is connected to the rotating shaft 31 through a coupling. Several stirring blades 32 are evenly arranged on the circumferential surface of the rotating shaft 31. The geared motor 3 drives the stirring blades 32 to rotate at low speed through the rotating shaft 31, which can improve the extraction efficiency and reduce the tendency of cerium sulfate to crystallize and precipitate.

[0023] In a further preferred embodiment, the lower part of the tank 1 is conical to assist in material discharge; the bottom end of the rotating shaft 31 is provided with a conical spiral stirring paddle 33 corresponding to the lower part of the tank 1. When the spiral stirring paddle 33 rotates, it will transport the mixed liquid at the bottom upward, making the mixing more uniform, while avoiding bottom sedimentation that could cause blockage.

[0024] The geared motor 3, centrifugal pump 7, pneumatic butterfly valve, etc. are all electrically connected to external control switches or controllers, preferably to controllers such as PLC controllers. The continuous gradient addition of the extractant is achieved through intelligent control of centrifugal pump 7 and pneumatic butterfly valve by the controller. Taking a five-stage tank as an example, the addition process is as follows: Initial filling: 100% concentration P507 kerosene solution is injected into tank 1, and blank organic phase is injected into tanks 2 to 5; Gradient operation: PLC starts pump 1 to feed material into tank 2 at 2L / min, while pump 2 feeds material into tank 3 at 1.8L / min (decline rate 10%); When the concentration in tank 3 reaches 60% in real time by ED-XRF spectrometer or sound velocity concentration meter, the pump speed is automatically reduced to 1.5L / min.

[0025] The geared motor 3, centrifugal pump 7, pneumatic butterfly valve and controller used in this application are all commonly used electronic components in the prior art. Their specific structures, working principles, control methods and circuit connections are all well-known technologies and will not be described in detail here.

[0026] In a preferred embodiment, the tank 1 is equipped with a spraying device, which can perform online cleaning after shutdown, improve the residual liquid discharge rate, and prevent cross-contamination between batches.

[0027] Specifically, the spraying device includes a spray liquid inlet pipe 4 installed on the upper side of the tank 1. The spray liquid inlet pipe 4 is connected to an external liquid delivery device for conveying oxalic acid and pure water. The former is used to clean the residual mixture in the tank 1, and the latter is used to clean the cleaning liquid residue.

[0028] The spray liquid inlet pipe 4 penetrates into the tank body 1 and connects to the annular spray pipe 41. Several connecting rods 42, which connect to the inner wall of the tank body 1, are evenly arranged on the upper surface of the annular spray pipe 41. Several spray heads 43 are evenly arranged on the lower surface of the annular spray pipe 41. The spray heads 43 are wide-angle fan-shaped nozzles (spray angle ≥ 120°), with a coverage radius > tank radius. Through the annular spray pipe 41 and its spray heads 43, the cleaning liquid covers the tank bottom, side walls, and stirring blades, achieving a residual extractant removal rate > 99.8%. Compared to traditional single-point spraying, this method improves cleaning efficiency while reducing oxalic acid usage.

[0029] In a further preferred embodiment, two annular spray pipes 41 are provided, which are concentrically arranged and connected by a connecting pipe, thereby further increasing the spray coverage area and providing more comprehensive cleaning of the stirring blades, etc.

[0030] Furthermore, the outlet of the spray head 43 on the outer annular spray pipe 41 is inclined to the lower outer part to clean the residue on the inner wall of the tank 1. The spray head 43 on the inner annular spray pipe 41 is located at various angles, but all face downwards. During the cleaning process, the reduction motor 3 can be turned on to make the rotating shaft 31 drive the stirring blade 32 and other components to rotate, so as to achieve all-round residue cleaning.

[0031] A drain pipe 5 is installed at the bottom of the tank 1, and a drain valve 51 is installed on the drain pipe 5. After the machine is stopped, the spray head is turned on, and a 5% oxalic acid solution is injected for circulation cleaning for 20 minutes. The residual liquid is discharged from the drain valve 51.

[0032] Optionally, a transparent observation window 9 is provided on the side surface of the tank 1 to facilitate visual monitoring of the extraction process by staff.

[0033] The parts not disclosed in this utility model are all prior art, and their specific structures, materials, and working principles will not be described in detail. Although embodiments of this utility model have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of this utility model, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A device for continuous gradient addition of extractant in lanthanum-cerium separation process, comprising a plurality of tank bodies (1), characterized in that: The upper surface of the tank (1) is provided with a feed pipe (2), the side surface of the tank (1) is provided with a conduit (6) connected to the adjacent tank (1), and the side surface of the tank (1) at the end is provided with a discharge pipe (8). Centrifugal pumps (7) are provided on both the discharge pipe (8) and the conduit (6); a low-speed stirring device and a spraying device are provided on the tank (1).

2. The device for continuous gradient addition of extractant in a process for separation of lanthanides and cerium according to claim 1, characterized in that: The low-speed stirring device includes a speed reduction motor (3) installed at the center of the upper surface of the tank (1). The output shaft of the speed reduction motor (3) passes into the tank (1) and is connected to the rotating shaft (31) through a coupling. Several stirring blades (32) are evenly arranged on the circumferential surface of the rotating shaft (31).

3. The device for continuous gradient addition of extractant in a lanthanum-cerium separation process according to claim 2, characterized in that: The lower part of the tank (1) is conical, and the bottom end of the rotating shaft (31) is provided with a conical spiral stirring paddle (33) corresponding to the lower part of the tank (1).

4. The device for continuous gradient addition of extractant in a process for separation of lanthanides and cerium according to claim 1, characterized in that: The spraying device includes a spray liquid inlet pipe (4) set on the upper side of the tank (1). The spray liquid inlet pipe (4) passes into the tank (1) and is connected to the annular spray pipe (41). The upper surface of the annular spray pipe (41) is uniformly provided with a number of connecting rods (42) that are connected to the inner wall of the tank (1). The lower surface of the annular spray pipe (41) is uniformly provided with a number of spray heads (43).

5. The device for continuous gradient addition of extractant in a process for separation of lanthanides and cerium according to claim 4, characterized in that: There are two annular spray pipes (41), which are arranged concentrically and connected by a connecting pipe.

6. The device for continuous gradient addition of extractant in a lanthanum-cerium separation process according to claim 4 or 5, characterized in that: The outlet of the spray head (43) installed on the annular spray pipe (41) is inclined to the lower part of the outside.

7. The device for continuous gradient addition of extractant in a process for separation of lanthanides and cerium according to claim 6, characterized in that: The bottom of the tank (1) is provided with a drain pipe (5) and a drain valve (51) is installed on the drain pipe (5).

8. A continuous gradient addition device for extractant in a lanthanum-cerium separation process according to any one of claims 1-7, characterized in that: The side surface of the tank (1) is provided with a transparent observation window (9).

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