Device for producing iron phosphate by using waste lithium iron phosphate lithium extraction slag

Abstract

The utility model relates to a device for producing iron phosphate by using waste lithium iron phosphate lithium extraction slag, which is characterized in that a lower outlet of a dissolving tank is connected into a leaching reaction kettle through a slurry delivery pump, an outlet of the leaching reaction kettle is connected with a first solid-liquid separation device through a leachate delivery pump, and a liquid outlet of the first solid-liquid separation device is connected into a mother liquor tank; a bottom outlet of the reaction kettle is connected with a second solid-liquid separation device; a solid outlet of the second solid-liquid separation device is connected to an aging reaction kettle; a bottom outlet of the aging reaction kettle is connected with a third solid-liquid separation device; a solid outlet of the third solid-liquid separation device is connected to a drying device; the calcining device outlet is connected with the crushing device. The system is simple in structure and scientific and reasonable in design and layout, realizes automatic production of producing iron phosphate by using the waste lithium iron phosphate extraction slag and automatic monitoring of a production process, is beneficial to production management and control, can meet complex production requirements, saves a large amount of manpower, reduces energy consumption and reduces production cost.

Description

Technical Field

[0001] The utility model belongs to the technical field of lithium-ion battery recycling, and particularly relates to a device for producing iron phosphate by using lithium-extracted slag from waste lithium iron phosphate. Background Art

[0002] In recent years, China's new energy industry has developed vigorously. Lithium iron phosphate batteries have become the main power source for electric vehicles due to their excellent cost performance. With the wide use of lithium iron phosphate batteries, a large number of waste batteries will be generated in the next few years. These huge amounts of waste lithium iron phosphate batteries contain rich lithium, iron, and phosphorus elements, and the economic benefits of recycling are considerable, with broad development prospects.

[0003] The current conventional wet oxidation recycling process device only recovers high-value lithium as lithium carbonate or lithium hydroxide, and the lithium-extracted slag is basically directly stacked in the form of waste, not only failing to maximize the utilization of iron and phosphorus resources, but also causing great pollution to the environment. For the recovery of phosphorus and iron elements in the lithium-extracted slag, existing devices mostly use high-concentration inorganic acids for dissolution, and adjust the pH of the leaching filtrate to precipitate iron phosphate. The prepared iron phosphate finished product has high impurity content, low iron-phosphorus ratio, large consumption of acids and alkalis, low leaching rates of iron and phosphorus elements, large resource waste, low economic benefits, and is not environmentally friendly. Content of the Utility Model

[0004] The purpose of the utility model is to solve the above problems and provide a device for producing iron phosphate by using lithium-extracted slag from waste lithium iron phosphate.

[0005] To achieve the above purpose, the utility model adopts the following technical scheme: A device for producing iron phosphate by using lithium-extracted slag from waste lithium iron phosphate, characterized in that: the lower outlet of the dissolution tank is connected to the leaching reaction kettle through a slurry delivery pump, the bottom outlet of the leaching reaction kettle is connected to the first solid-liquid separation device through a leaching solution delivery pump, the liquid outlet of the first solid-liquid separation device is connected to the mother liquid tank, the lower outlet of the mother liquid tank is connected to the reaction kettle through a mother liquid delivery pump, the bottom outlet of the reaction kettle is connected to the second solid-liquid separation device through a synthetic slurry delivery pump, the solid outlet of the second solid-liquid separation device is connected to the aging reaction kettle through a first belt conveyor, the bottom outlet of the aging reaction kettle is connected to the third solid-liquid separation device through an aging slurry delivery pump, the solid outlet of the third solid-liquid separation device is connected to the drying device through a second belt conveyor, the outlet of the drying device is connected to the calcination device, and the outlet of the calcination device is connected to the pulverization device;

[0006] The discharge pipe connecting the lithium extraction residue metering tank is connected to the dissolution tank, and the lithium extraction residue metering tank is arranged on the first weighing device; the discharge pipe of the reducing agent metering tank and the liquid discharge pipe of the inorganic acid metering tank are respectively connected to the leaching reactor, the reducing agent metering tank is arranged on the second weighing device, and the inorganic acid metering tank is arranged on the third weighing device; the discharge pipe of the oxidizing agent metering tank and the liquid discharge pipe of the ammonia water metering tank are respectively connected to the reactor, the oxidizing agent metering tank is arranged on the fourth weighing device, and the ammonia water metering tank is arranged on the fifth weighing device; the liquid discharge pipe of the phosphoric acid metering tank is connected to the aging reactor, and the phosphoric acid metering tank is arranged on the sixth weighing device.

[0007] Agitators are provided in the dissolution tank, leaching reactor, reactor and aging reactor, and the control input end of the agitator is correspondingly connected to the control output end of the controller.

[0008] Thermometers and pH meters are provided on the leaching reactor, reactor and aging reactor; the signal output ends of the thermometers and pH meters are correspondingly connected to the signal input ends of the controller.

[0009] Heating devices are covered on the outer peripheries of the leaching reactor, reactor and aging reactor.

[0010] Desalination water pipes are connected to the dissolution tank and the aging reactor, and flow meters are provided on the desalination water pipes; the signal output ends of the flow meters are correspondingly connected to the signal input ends of the controller.

[0011] The signal output ends of the first weighing device, second weighing device, third weighing device, fourth weighing device, fifth weighing device and sixth weighing device are correspondingly connected to the signal input ends of the controller;

[0012] The control input ends of the slurry transfer pump, leaching solution transfer pump, mother liquor transfer pump, synthetic slurry transfer pump, aging slurry transfer pump, first belt conveyor, second belt conveyor, first solid-liquid separation device, second solid-liquid separation device and third solid-liquid separation device are correspondingly connected to the control output ends of the controller.

[0013] The agitator is controlled by a frequency converter for speed control.

[0014] The heating device is a steam tracing pipe or an immersed coil heat exchanger.

[0015] The controller is a DCS controller or a PLC controller.

[0016] The beneficial effects of the present utility model are as follows: The design is scientifically reasonable. Each process is controlled by a controller, realizing the automated production of iron phosphate using waste lithium iron phosphate slag for lithium extraction and the automated monitoring of the production process. Moreover, fewer impurities are introduced into the product during the production process, the yield is higher, and it is conducive to production management and control. It can meet complex production requirements, save a large amount of labor, reduce energy consumption, and reduce production costs. Brief Description of the Drawings

[0017] Figure 1 It is a schematic diagram of the present utility model.

[0018] In the figure: 1 - dissolution tank, 2 - leaching reactor, 3 - first solid-liquid separation device, 4 - mother liquor tank, 5 - reactor, 6 - second solid-liquid separation device, 7 - aging reactor, 8 - third solid-liquid separation device, 9 - drying device, 10 - calcination device, 11 - crushing device;

[0019] A1 - lithium extraction slag metering tank, A2 - reducing agent metering tank, A3 - inorganic acid metering tank, A4 - oxidizing agent metering tank, A5 - ammonia water metering tank, A6 - phosphoric acid metering tank; B1 - slurry transfer pump, B2 - leaching solution transfer pump, B3 - mother liquor transfer pump, B4 - synthetic slurry transfer pump, B5 - aging slurry transfer pump; C1 - first belt conveyor, C2 - second belt conveyor; D1 - first weighing device, D2 - second weighing device, D3 - third weighing device, D4 - fourth weighing device, D5 - fifth weighing device, D6 - sixth weighing device. Detailed Embodiments

[0020] The principles and features of the present invention will be described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0021] Embodiment 1: A device for producing iron phosphate using waste lithium iron phosphate slag for lithium extraction, characterized in that: the lower outlet of the dissolution tank 1 is connected to the leaching reactor 2 through the slurry transfer pump B1, the bottom outlet of the leaching reactor 2 is connected to the first solid-liquid separation device 3 through the leaching solution transfer pump B2, the liquid outlet of the first solid-liquid separation device 3 is connected to the mother liquor tank 4, the lower outlet of the mother liquor tank 4 is connected to the reactor 5 through the mother liquor transfer pump B3, the bottom outlet of the reactor 5 is connected to the second solid-liquid separation device 6 through the synthetic slurry transfer pump B4, the solid outlet of the second solid-liquid separation device 6 is connected to the aging reactor 7 through the first belt conveyor C1, the bottom outlet of the aging reactor 7 is connected to the third solid-liquid separation device 8 through the aging slurry transfer pump B5, the solid outlet of the third solid-liquid separation device 8 is connected to the drying device 9 through the second belt conveyor C2, the outlet of the drying device 9 is connected to the calcination device 10, and the outlet of the calcination device 10 is connected to the crushing device 11;

[0022] The discharge pipe connecting the lithium extraction residue metering tank A1 is connected to the dissolution tank 1, and the lithium extraction residue metering tank A1 is arranged on the first weighing device D1; the discharge pipe of the reducing agent metering tank A2 and the liquid outlet pipe of the inorganic acid metering tank A3 are respectively connected to the leaching reactor 2, the reducing agent metering tank A2 is arranged on the second weighing device D2, and the inorganic acid metering tank A3 is arranged on the third weighing device D3; the discharge pipe of the oxidizing agent metering tank A4 and the liquid outlet pipe of the ammonia water metering tank A5 are respectively connected to the reactor 5, the oxidizing agent metering tank A4 is arranged on the fourth weighing device D4, and the ammonia water metering tank A5 is arranged on the fifth weighing device D5; the liquid outlet pipe of the phosphoric acid metering tank A6 is connected to the aging reactor 7, and the phosphoric acid metering tank A6 is arranged on the sixth weighing device D6.

[0023] Stirrers are provided in the dissolution tank 1, the leaching reactor 2, the reactor 5 and the aging reactor 7, and the control input end of the stirrer is correspondingly connected to the control output end of the controller.

[0024] Thermometers and pH meters are provided on the leaching reactor 2, the reactor 5 and the aging reactor 7; the signal output ends of the thermometers and pH meters are correspondingly connected to the signal input end of the controller.

[0025] Heating devices are covered on the outer peripheries of the leaching reactor 2, the reactor 5 and the aging reactor 7.

[0026] Desalting water pipes are connected to the dissolution tank 1 and the aging reactor 7, and flow meters are provided on the desalting water pipes; the signal output end of the flow meter is correspondingly connected to the signal input end of the controller.

[0027] The signal output ends of the first weighing device D1, the second weighing device D2, the third weighing device D3, the fourth weighing device D4, the fifth weighing device D5 and the sixth weighing device D6 are correspondingly connected to the signal input end of the controller;

[0028] The control input ends of the slurry transfer pump B1, the leaching solution transfer pump B2, the mother liquor transfer pump B3, the synthetic slurry transfer pump B4, the aging slurry transfer pump B5, the first belt conveyor C1, the second belt conveyor C2, the first solid-liquid separation device 3, the second solid-liquid separation device 6, and the third solid-liquid separation device 8 are correspondingly connected to the control output end of the controller.

[0029] The stirrer is controlled by a frequency converter for speed control.

[0030] The heating device is a steam tracing pipe or an immersed coil heat exchanger.

[0031] The controller is a DCS controller or a PLC controller.

[0032] The working process of the present utility model:

[0033] Step 1: The lithium-extracted slag of lithium iron phosphate is placed in the lithium-extracted slag metering tank A1, weighed by the first weighing device D1 and added into the dissolution tank 1. At the same time, a certain amount of desalted water is added into the dissolution tank 1 through the desalinated water pipe, and the stirrer is started to stir into a slurry;

[0034] Step 2: The dissolved slurry is transferred to the leaching reactor 2 through the slurry transfer pump B1 through the pipeline, and a fixed proportion of reducing agent and inorganic acid are added to the leaching reactor 2 through the reducing agent metering tank A2 and the inorganic acid metering tank A3. The pH value of the material is monitored by a pH meter, and the pH is adjusted to the technical index and then stirred evenly; the material is heated through the steam tracing pipe, and the temperature value of the material is detected by a thermometer. When the temperature meets the technical index requirements, wait for enough time to obtain the iron phosphate leaching solution;

[0035] Step 3: The iron phosphate leaching solution is sent to the first solid-liquid separation device 3 through the leaching solution transfer pump B2 for solid-liquid separation, and the mother liquor enters the mother liquor tank 4 for collection;

[0036] Step 4: The mother liquor is transferred to the reactor 5 through the mother liquor transfer pump B3, and a certain amount of oxidant and ammonia water are added into the reactor 5 through the oxidant metering tank A4 and the ammonia water metering tank A5. The stirrer is started, and the pH value of the material is monitored by a pH meter to make the pH of the material within the range of the process technical index. During the reaction process, the reactor 5 is heated through the steam tracing pipe, and the temperature value of the material is detected by a thermometer. After the reaction is completed, the synthetic slurry is obtained;

[0037] Step 5: The synthetic slurry is sent to the second solid-liquid separation device 6 through the synthetic slurry transfer pump B4 for solid-liquid separation, and the filter cake is washed with desalted water. The washing qualification can be judged according to the conductivity; after the washing is qualified, the first-stage filter cake is obtained;

[0038] Step 6: The first-stage filter cake is transferred to the aging reactor 7 through the first belt conveyor C1, and a certain amount of desalted water is added into the aging reactor 7 through the desalted water pipe, and a certain amount of phosphoric acid is added into the aging reactor 7 through the phosphoric acid metering tank A6. The stirrer is started, and the pH value of the material is monitored by a pH meter. The aging reactor 7 is heated through the steam tracing pipe, and the temperature value of the material is detected by a thermometer. After the reaction is completed, the aged slurry is obtained;

[0039] Step 7: The aged slurry is sent to the third solid-liquid separation device 8 through the aged slurry transfer pump B5 for solid-liquid separation, and the filter cake is washed with desalted water. The washing qualification can be judged according to the conductivity; after the washing is qualified, the second-stage filter cake is obtained;

[0040] Step 8: Transfer the secondary filter cake to the drying device 9 through the second belt conveyor C2 for drying to remove free water and obtain iron phosphate dihydrate; the iron phosphate dihydrate after drying and dehydration is transported to the calcination device 10 for calcination to remove crystal water and obtain iron phosphate; finally, the calcined iron phosphate is ground by the grinding device 11 to obtain the final product.

[0041] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An apparatus for producing iron phosphate using lithium-extracted slag from waste lithium iron phosphate, characterized in that: The lower outlet of the dissolution tank (1) is connected to the leaching reactor (2) through the slurry transfer pump (B1). The bottom outlet of the leaching reactor (2) is connected to the first solid-liquid separation device (3) through the leaching solution transfer pump (B2). The liquid outlet of the first solid-liquid separation device (3) is connected to the mother liquor tank (4). The lower outlet of the mother liquor tank (4) is connected to the reactor (5) through the mother liquor transfer pump (B3). The bottom outlet of the reactor (5) is connected to the second solid-liquid separation device (6) through the synthetic slurry transfer pump (B4). The solid outlet of the second solid-liquid separation device (6) is connected to the aging reactor (7) through the first belt conveyor (C1). The bottom outlet of the aging reactor (7) is connected to the third solid-liquid separation device (8) through the aging slurry transfer pump (B5). The solid outlet of the third solid-liquid separation device (8) is connected to the drying device (9) through the second belt conveyor (C2). The outlet of the drying device (9) is connected to the calcination device (10). The outlet of the calcination device (10) is connected to the pulverizing device (11); The discharge pipe of the lithium extraction residue metering tank (A1) is connected to the dissolution tank (1), and the lithium extraction residue metering tank (A1) is arranged on the first weighing device (D1); the discharge pipe of the reducing agent metering tank (A2) and the liquid discharge pipe of the inorganic acid metering tank (A3) are respectively connected to the leaching reactor (2). The reducing agent metering tank (A2) is arranged on the second weighing device (D2), and the inorganic acid metering tank (A3) is arranged on the third weighing device (D3); the discharge pipe of the oxidizing agent metering tank (A4) and the liquid discharge pipe of the ammonia water metering tank (A5) are respectively connected to the reactor (5). The oxidizing agent metering tank (A4) is arranged on the fourth weighing device (D4), and the ammonia water metering tank (A5) is arranged on the fifth weighing device (D5); the liquid discharge pipe of the phosphoric acid metering tank (A6) is connected to the aging reactor (7), and the phosphoric acid metering tank (A6) is arranged on the sixth weighing device (D6).

2. The device for producing iron phosphate by using lithium extraction slag from waste lithium iron phosphate as claimed in claim 1, wherein: Agitators are provided in the dissolution tank (1), the leaching reactor (2), the reactor (5) and the aging reactor (7), and the control input ends of the agitators are correspondingly connected to the control output ends of the controller.

3. The device for producing iron phosphate using lithium-extracted slag from waste lithium iron phosphate as claimed in claim 1, wherein: Thermometers and pH meters are provided on the leaching reactor (2), the reactor (5) and the aging reactor (7); the signal output ends of the thermometers and pH meters are correspondingly connected to the signal input ends of the controller.

4. The device for producing iron phosphate by using lithium extraction slag from waste lithium iron phosphate as claimed in claim 1, wherein: Heating devices are covered on the outer peripheries of the leaching reactor (2), the reactor (5) and the aging reactor (7).

5. The device for producing iron phosphate by using lithium-extracted slag from waste lithium iron phosphate as claimed in claim 1, wherein: Desalination water pipes are connected to the dissolution tank (1) and the aging reactor (7), and flow meters are provided on the desalination water pipes; the signal output ends of the flow meters are correspondingly connected to the signal input ends of the controller.

6. The device for producing iron phosphate by using lithium-extracted slag from waste lithium iron phosphate as claimed in claim 1, wherein: The signal output ends of the first weighing device (D1), the second weighing device (D2), the third weighing device (D3), the fourth weighing device (D4), the fifth weighing device (D5) and the sixth weighing device (D6) are correspondingly connected to the signal input ends of the controller; The control input ends of the slurry transfer pump (B1), leaching solution transfer pump (B2), mother liquor transfer pump (B3), synthetic slurry transfer pump (B4), aged slurry transfer pump (B5), first belt conveyor (C1), second belt conveyor (C2), first solid-liquid separation device (3), second solid-liquid separation device (6), and third solid-liquid separation device (8) are correspondingly connected to the control output end of the controller.

7. An apparatus for producing iron phosphate using lithium-extracted slag from waste lithium iron phosphate as claimed in claim 2, characterized in that: The agitator is controlled by a frequency converter for speed control.

8. An apparatus for producing iron phosphate using waste lithium iron phosphate slag for lithium extraction according to claim 4, characterized in that: The heating device is a steam tracing pipe or an immersed coil heat exchanger.

9. A device for producing iron phosphate using lithium-extracted slag from waste lithium iron phosphate as claimed in any one of claims 2, 3, 5, and 6, characterized in that: The controller is a DCS controller or a PLC controller.

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