Process control system of cascade lithium extraction reaction kettle

Abstract

The utility model discloses a process control system of a cascade type lithium extraction reaction kettle, the cascade type lithium extraction reaction kettle comprises N reaction kettles, and the N reaction kettles are divided into M groups; the M groups of reaction kettles are configured in a stepped manner; each group of reaction kettles are connected through a reaction liquid overflow tank; the reaction liquid overflow tanks of the adjacent groups of reaction kettles are communicated through a connecting pipeline; each reaction kettle is provided with a field controller for controlling the reaction kettle; the field controller is used for controlling the on-off of a slurry inflow and outflow channel of the current reaction kettle through the first electric control valve, and further controlling the on-off of an overflow tank of the reaction kettle through the second electric control valve; the on-site controller further controls connection and disconnection of the connecting pipeline through a third electric control valve. And the control center is in communication connection with the plurality of field controllers through a field bus. The process control system disclosed by the utility model adopts distributed control, can realize continuous lithium extraction, and is easy to realize a control target.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of process control system of cascade lithium extraction reaction kettle. BACKGROUND

[0002] The process for extracting lithium using recycled lithium battery waste requires multiple steps, such as sodium removal reaction, lithium extraction reaction, impurity removal reaction, and lithium precipitation reaction. To ensure the controllability of the entire system, multiple reaction kettles are typically involved in the entire process. The challenge is to simplify the control process to ensure the implementation of the process.

[0003] Therefore, it is necessary to design a new system for extracting lithium from waste electrolyte. SUMMARY

[0004] The technical problem to be solved by the utility model is to provide a process control system for a cascade lithium extraction reaction kettle. The process control system for the cascade lithium extraction reaction kettle uses distributed control based on field bus, which facilitates the process control of the entire continuous lithium extraction process.

[0005] The technical solution of the utility model is as follows:

[0006] A process control system for a cascade lithium extraction reaction kettle,

[0007] The cascade lithium extraction reaction kettle includes N reaction kettles, which are divided into M groups. Each group includes at least two reaction kettles.

[0008] M and N are natural numbers, M ≥ 4, and N ≥ 8.

[0009] The M groups of reaction kettles are arranged in a step-by-step manner. Each group of reaction kettles is connected through a reaction liquid overflow tank. The reaction liquid overflow tanks of adjacent groups of reaction kettles are connected through a connecting pipeline.

[0010] A field controller is provided for each reaction kettle to control the reaction kettle.

[0011] The field controller controls the on-off of the slurry flow into and out of the current reaction kettle through a first electric control valve. The field controller also controls the on-off of the reaction kettle overflow tank through a second electric control valve. The field controller also controls the on-off of the connecting pipeline through a third electric control valve.

[0012] The control center is in communication connection with the multiple field controllers through a field bus.

[0013] The field bus is a CAN bus.

[0014] The reaction kettle is connected with the reaction liquid overflow groove through a reaction liquid overflow groove; the reaction kettle is connected with the reaction liquid overflow groove through a reaction kettle inflow pipeline and a reaction liquid overflow pipeline; the reaction kettle inflow pipeline and the reaction liquid overflow pipeline are provided with the first electric control valve; the reaction liquid overflow groove is provided with a plurality of second electric control valves; the reaction liquid overflow grooves of adjacent groups of reaction kettles are communicated through a connecting pipeline provided with a third electric control valve.

[0015] The reaction kettle is provided with a temperature sensor, a stirring mechanism and a heating mechanism; the temperature sensor is connected with a data acquisition end of the field controller, and the stirring mechanism and the heating mechanism are controlled by the field controller.

[0016] The field controller adopts a DSP or PLC processor.

[0017] The control center adopts an industrial computer; and the control center is in communication connection with a cloud server.

[0018] M=4; the four groups of reaction kettles are a sodium removal reaction kettle, a lithium extraction reaction kettle, an impurity removal reaction kettle and a lithium precipitation reaction kettle; and the adjacent groups of reaction kettles are staggered at a distance not less than the height of the kettle body.

[0019] The kettle body is provided with a reaction liquid flow guide mechanism; the kettle body is further provided with a feeding pipe; the kettle wall of the kettle body is provided with a reaction kettle inflow pipeline and a reaction liquid overflow pipeline provided with a first electric control valve; and the inside of the kettle body is provided with a heating device.

[0020] The reaction liquid flow guide mechanism is a plurality of vertical flow guide pipes, and the bottom of the flow guide pipe is communicated with the bottom of the kettle body.

[0021] The stirring mechanism has a plurality of layers of paddles; the inside bottom surface of the reaction kettle is provided with a chamfer; the feeding pipe is a plurality of vertical pipes, and the discharge ports of the plurality of feeding pipes are located at different depths in the kettle body.

[0022] Beneficial effects:

[0023] The process control system of the cascade lithium extraction reaction kettle adopts the reaction kettles in a ladder type cascade to realize continuous lithium extraction process, so that each process can correspond to 2-3 reaction kettles (which can contain one standby reaction kettle), which is beneficial to improve the robustness of the system, and the standby reaction kettle is arranged, so that the entire process can be adjusted on site once an unpredictable problem occurs in any link, and each reaction kettle can complete all reaction links. When abnormal conditions such as material changes, equipment failures and human factors occur, the subsequent reaction kettles can also complete the remaining reactions. Therefore, compared with the non-cascade single reaction kettle, the cascade lithium extraction reaction kettle has the advantage of higher reliability.

[0024] By using this method, a first reaction kettle can also be directly cut off from the entire system, so that the risk resistance of the entire system is effectively improved.

[0025] The utility model discloses a distributed control is adopted, is convenient for the layout of control line, and control is simple, and each reaction kettle is located at the position and has a field controller, is equivalent to slave, and the host computer issues control instruction unification, thereby realizes centralized control.

[0026] In addition, the reaction kettle is provided with multilayer stirring paddles, is favorable for stirring fully, a plurality of flow guide devices are arranged in the kettle body, is favorable for reaction fully, a plurality of reaction kettles share an overflow groove, the flow direction of slurry and control which reaction kettle participates in reaction are controlled through electric control valve, is convenient for realizing continuous lithium extraction process. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is 12 reaction kettle cascade schematic diagram (top view);

[0028] Figure 2 It is 4 reaction kettle step arrangement view (side view);

[0029] Figure 3 It is reaction kettle structure schematic diagram (main view section);

[0030] Figure 4 It is reaction kettle and overflow groove connection view (top view);

[0031] Figure 5 It is system electric control block diagram.

[0032] Label explanation: 1-reaction kettle, 2-reaction liquid overflow groove, 3-reaction liquid inflow pipeline, 4-reaction liquid outflow pipeline, 5-first electric control valve, 6-second electric control valve, 7-stirring mechanism, 8-reaction liquid flow guide mechanism, 9-feeding pipe. 10-connection pipeline, 11-third electric control valve. DETAILED DESCRIPTION

[0033] The utility model will make further detailed explanation in combination with the drawings and specific embodiment:

[0034] Example 1: as Figures 1-5 A process control system of cascade lithium extraction reaction kettle,

[0035] The cascade lithium extraction reaction kettle includes 12 reaction kettles, and the 12 reaction kettles are divided into 4 groups;

[0036] Each group includes 3 reaction kettles;

[0037] 4 reaction kettle step configurations;Each group of reaction kettles is connected through reaction liquid overflow groove;The reaction liquid overflow groove of adjacent group reaction kettle is communicated through connection pipeline;Four groups of reaction kettles are sodium removal reaction kettle, lithium extraction reaction kettle, impurity removal reaction kettle and lithium precipitation reaction kettle respectively;The distance of adjacent group reaction kettle is staggered and is not less than the height of kettle body.

[0038] Each reaction kettle is provided with a field controller for controlling the reaction kettle;

[0039] The field controller is used for controlling the on-off of the slurry inflow-outflow channel of the current reaction kettle through the first electric control valve, and controlling the on-off of the reaction kettle overflow tank through the second electric control valve; the field controller is also used for controlling the on-off of the connecting pipeline through the third electric control valve;

[0040] The control center is in communication connection with the plurality of field controllers through the field bus.

[0041] The field bus is a CAN bus.

[0042] The reaction kettle is connected with the reaction liquid overflow tank through the reaction liquid overflow tank 2; the reaction kettle is connected with the reaction liquid overflow tank through the reaction kettle inflow pipeline 3 and the reaction liquid overflow pipeline 4; the reaction kettle inflow pipeline and the reaction liquid overflow pipeline are provided with the first electric control valve 5; the reaction liquid overflow tank is provided with a plurality of second electric control valves 6; the reaction liquid overflow tanks of adjacent groups of reaction kettles are communicated through the connecting pipeline 10 provided with the third electric control valve 11.

[0043] The reaction kettle is provided with a temperature sensor, a stirring mechanism and a heating mechanism; the temperature sensor is connected with the data acquisition end of the field controller, and the stirring mechanism and the heating mechanism are controlled by the field controller.

[0044] The field controller adopts a DSP or PLC processor.

[0045] The control center adopts an industrial computer; the control center is in communication connection with a cloud server.

[0046] M=4; the four groups of reaction kettles are a sodium removal reaction kettle, a lithium extraction reaction kettle, an impurity removal reaction kettle and a lithium precipitation reaction kettle; the adjacent groups of reaction kettles are staggered at a distance not less than the height of the kettle body.

[0047] The kettle body is provided with a reaction liquid flow guide mechanism; the kettle body is also provided with a feeding pipe; the kettle wall of the kettle body is provided with the reaction kettle inflow pipeline and the reaction liquid overflow pipeline provided with the first electric control valve; the inside of the kettle body is provided with a heating device;

[0048] The reaction liquid flow guide mechanism is a plurality of vertical flow guide pipes, and the bottom of the flow guide pipe is in communication with the bottom of the kettle body.

[0049] The process corresponding to the sodium removal reaction kettle, lithium extraction reaction kettle, impurity removal reaction kettle and lithium precipitation reaction kettle is: step 1: sodium removal step; bottom water is added to the sodium removal reaction kettle, the ball mill slurry (slurry after ball milling of the raw material waste aluminum electrolyte) is transferred into the sodium removal reaction kettle and stirring is started; the slurry in the sodium removal reaction kettle is heated to 25-100 DEG C; lime milk is further added and stirring is performed, so that the lime milk and the slurry are reacted, and a precipitate is obtained after the reaction; step 2: continuous lithium extraction step; in the continuous lithium extraction reaction kettle, insoluble solids and water are prepared in a mass ratio of 1:0.5-10, stirring is started, and sulfuric acid is added; the aluminum sulfate is converted into insoluble aluminum hydroxide and calcium sulfate precipitate; step 3: impurity removal step; step 4: lithium precipitation step; the lithium sulfate solution after impurity removal and soda lye are added to the continuous lithium precipitation reaction kettle, heating is performed for lithium precipitation reaction, so that lithium carbonate precipitates; after solid-liquid separation, lithium carbonate and lithium precipitation mother liquor are obtained.

[0050] The temperature sensor is connected with the controller. The temperature sensor is used in cooperation with the heating device to ensure that the reaction temperature in the reaction kettle is constant within a preset range, thereby ensuring efficient reaction.

[0051] The reaction liquid flow guide mechanism is vertical, and the bottom of the flow guide pipe is communicated with the bottom of the kettle body. The plurality of reaction liquid flow guide mechanisms facilitate the rapid entry and exit of the reaction liquid into the reaction kettle and facilitate the full reaction.

[0052] The inside bottom of the reaction kettle is provided with a chamfered corner. That is, the inside bottom of the reaction kettle is a conical bottom.

[0053] The plurality of feeding pipes are vertical, and the discharge openings of the plurality of feeding pipes are located at different depths in the kettle body. The plurality of feeding pipes are not shown in the figure. Different substances with different densities can be added, and the substances with greater density are added from the feeding pipes with greater depth.

[0054] The reaction kettle has the following characteristics:

[0055] 1. The reaction kettles are arranged in groups and stages, and can be switched at any time when applied to continuous reaction. The controller can switch which reaction kettle is put into use through the first electric control valve and the second control valve, and can also control whether the reaction liquid passes through or bypasses a certain reaction kettle through the second valve.

[0056] 2. The multi-stage reaction kettles are arranged from high to low (in stages), so as to save energy consumption.

[0057] 3. The inlets of the reaction kettles are arranged at the upper, middle and lower parts of the kettle body. This arrangement is beneficial to the uniformity of the reaction of the materials.

[0058] 4. A plurality of flow guide devices are arranged on the inner side of the reaction kettle, which is beneficial to the full reaction.

[0059] 5. The reaction liquid overflow outlet is generally arranged in the middle upper part of the kettle body, and the specific gravity of the qualified liquid in the solid-liquid phase reaction is generally smaller than that of the solid phase.

[0060] 6. The inlet and outlet of each reaction kettle are arranged with automatically controllable baffles for controlling flow and opening and closing.

[0061] 7. The inside bottom surface of the reaction kettle is provided with a chamfer to prevent material deposition.

[0062] 8. The inside of the reaction kettle is provided with a heating device.

[0063] 9. The reaction kettle is provided with stirring, generally multiple layers of paddles, so that materials of different specific gravities can be fully mixed and reacted.

[0064] Any modification, equivalent replacement and improvement within the spirit and principles of the present utility model shall be included in the protection scope of the present utility model.

Claims

1. A process control system for a cascaded lithium extraction reactor, characterized in that: The cascaded lithium extraction reactor comprises N reactors, and the N reactors are divided into M groups; each group comprises at least 2 reactors. M and N are both natural numbers; and M≥4; N≥8; The M-group reactors are arranged in a stepped configuration; each group of reactors is connected by a reaction liquid overflow tank; the reaction liquid overflow tanks of adjacent groups of reactors are connected by connecting pipes. Each reactor is equipped with a field controller for controlling that reactor; The field controller is used to control the on / off of the slurry inflow and outflow channels of the current reactor through the first solenoid valve. The field controller also controls the on / off of the reactor overflow tank through the second solenoid valve. The field controller also controls the on / off of the connecting pipes through the third solenoid valve. The control center is connected to multiple field controllers via fieldbus communication.

2. The process control system for the cascaded lithium extraction reactor according to claim 1, characterized in that: The fieldbus mentioned is the CAN bus.

3. The process control system for the cascaded lithium extraction reactor according to claim 1, characterized in that: The reactors are connected by a reaction liquid overflow tank (2); the reactors are connected to the reaction liquid overflow tank through a reactor inflow pipe (3) and a reaction liquid overflow pipe (4); the reactor inflow pipe and the reaction liquid overflow pipe are both equipped with the first solenoid valve (5); the reaction liquid overflow tank is equipped with multiple second solenoid valves (6); the reaction liquid overflow tanks of the reactors in adjacent groups are connected by a connecting pipe (10) with a third solenoid valve (11).

4. The process control system for the cascaded lithium extraction reactor according to claim 1, characterized in that: The reactor is equipped with a temperature sensor, a stirring mechanism, and a heating mechanism; the temperature sensor is connected to the data acquisition terminal of the field controller, and the stirring mechanism and the heating mechanism are controlled by the field controller.

5. The process control system for the cascaded lithium extraction reactor according to claim 1, characterized in that: The field controller uses a DSP or PLC processor.

6. The process control system for the cascaded lithium extraction reactor according to any one of claims 1-5, characterized in that: The control center uses an industrial control computer; the control center communicates with the cloud server.

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