Recovery device of iron phosphate material

Abstract

The utility model discloses an iron phosphate material recovery device which comprises a cloth bag dust removal device which is connected with a rotary kiln and is used for collecting SO2, water vapor and part of iron phosphate materials in the kiln, a pulping tank for preparing tailings collected by the bag dust removal device into slurry and a conveying pump for pumping the slurry in the pulping tank into a transfer tank of the front-section wet process workshop for filter pressing and washing are arranged below the bag dust removal device. A rotary feeding valve for preventing blockage caused by adhesion of tailings in the bag-type dust removal device is arranged between the bag-type dust removal device and the pulping tank, so that the risk that a pipeline of the small bag-type dust removal device is bent to cause unsmooth tail powder discharging or stop caused by blockage of an induced draft fan is prevented; and meanwhile, the phenomenon that moisture discharged from the induced draft fan after long-time staying is mixed with SO2 gas and iron phosphate materials to form an adhesive sulfur-containing compound to cause pressure building of the induced draft fan is avoided, and the labor intensity of manual cleaning is reduced. And the S content of the finished product is reduced by 400ppm, equipment in the previous process is shared, the modification is simple, convenient and feasible, and the modification cost is low.

Description

Technical Field

[0001] The utility model relates to a powder recovery and reuse device, in particular to a device for recovering iron phosphate materials. Background Art

[0002] Iron phosphate is a white or off-white monoclinic crystalline powder with fine particles and low density. Batteries made with lithium iron phosphate (LIFP) have the advantages of high operating voltage, high energy density, long cycle life, good safety, low self-discharge, and no memory effect. With the development of new energy vehicles and the continuous depletion of mineral resources, LFP has been widely used in the new energy industry due to its cost advantage. The production process of LFP, the precursor of LFP, has stabilized. However, in a market that continuously pursues low cost and high quality, sulfur content has become a key indicator for controlling battery performance. During the production of LFP cathode materials, excessive sulfur content in the material can disrupt the layered structure and corrode the electrode. During normal production, the rotary kiln is equipped with an induced draft fan to remove moisture and SO2 generated during the calcination process. However, this operation also carries over some of the LFP material. To avoid waste of raw materials, the existing production line uses a small bag filter at the outlet of the induced draft fan to collect the air and return it to the rotary kiln. During operation, the iron phosphate material intercepted by the small bag dust collector is mixed with some sulfide and re-enters the kiln, resulting in the inability to effectively discharge the sulfur element in the production line, thereby increasing the sulfur content in the iron phosphate product, affecting the quality of the finished battery product; in addition, the small bag dust collector is generally installed on the side of the rotary kiln, and the bending of the pipeline will cause the tail powder to be discharged unsmoothly. In severe cases, it may block the induced draft fan and cause the risk of shutdown. If the induced draft fan is shut down for a long time, the moisture coming out of the induced draft fan will mix with the SO2 gas and the iron phosphate material to form sticky sulfur-containing compounds, causing the induced draft fan to be pressurized, making manual cleaning difficult. Utility Model Content

[0003] Purpose of the utility model: The purpose of the utility model is to provide a device for recovering iron phosphate materials in order to recover iron phosphate tailings while reducing the sulfur content in finished lithium iron phosphate batteries.

[0004] Technical solution: The iron phosphate material recovery device described in the utility model includes a bag dust removal device connected to a rotary kiln for collecting SO2, water vapor and part of the iron phosphate material inside the kiln. Below the bag dust removal device is a pulping tank for making the tailings collected by the bag dust removal device into slurry and a delivery pump for pumping the slurry in the pulping tank into the transfer tank of the front-stage wet process workshop for pressure filtration and washing.

[0005] Furthermore, a rotary feeding valve is provided between the bag dust collector and the pulping tank to prevent the tail material from sticking to the bag dust collector and causing blockage, thereby preventing the small bag dust collector pipe from bending, resulting in obstructed tail powder discharge or clogging the induced draft fan and causing the risk of shutdown. At the same time, it avoids the long-term residence of the induced draft fan, which prevents the moisture from mixing with the SO2 gas and the iron phosphate material to form sticky sulfur-containing compounds and cause the induced draft fan to be pressurized, thereby reducing the labor intensity of manual cleaning.

[0006] Furthermore, the pulping tank is provided with a water inlet for providing a certain amount of pure water into the tank, so as to facilitate adjustment of the pulping solid content of the collected iron phosphate tailings, making it more compatible and flexible with subsequent processes.

[0007] Furthermore, the beating tank is provided with a circulation device to increase the uniformity of internal slurry mixing. The circulation device uses a common delivery pump to pump the slurry at the bottom of the tank to the top to increase the mixing uniformity, so that the iron phosphate is beating more fully and evenly, ensuring the process production requirements.

[0008] Furthermore, the side wall of the pulping tank is provided with a liquid level gauge for displaying the liquid content in the tank, which is used to confirm the amount of pure water added and assist in determining the solid content of the slurry in the tank.

[0009] Furthermore, the beating tank is provided with an ultrasonic solid content detector for monitoring the solid content of the slurry in the tank, which is used to accurately monitor the solid content of the slurry.

[0010] Furthermore, a flow meter for monitoring the amount of slurry in the beating tank pumped into the transfer tank is set between the delivery pump and the transfer tank for filter pressing and washing. After the filter cake is pressed, the recycled filter cake and the normal filter cake are put into the next process at a ratio of 1:3.

[0011] Beneficial effects: Compared with the existing technology, the utility model has the following advantages: 1. Under the premise of meeting the recycling and reuse of iron phosphate tailings, the S content is reduced by 400ppm; 2. The rotary feeding valve alleviates or avoids the blockage of pipelines after the sulfur-containing and water-containing tailings are bonded, ensuring the normal operation of the production line and reducing the labor intensity of workers cleaning the bag dust removal device; 3. The equipment of the shared previous process is simple and easy to modify, and the transformation cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a structural diagram of the present utility model. DETAILED DESCRIPTION

[0013] The technical solution of the present utility model will be further described below with reference to the accompanying drawings.

[0014] like Figure 1The device for recovering iron phosphate materials shown in the figure includes a bag dust collector 1 connected to a rotary kiln for collecting SO2, water vapor and part of the iron phosphate material inside the kiln. A rotary feeding valve 2 is provided below the bag dust collector 1 to prevent the tailings from sticking to the bag dust collector 1 and causing blockage. A pulping tank 3 is provided below the rotary feeding valve 2 to make the tailings collected by the bag dust collector 1 into a slurry. A conveying pump 4 is provided at the bottom of the pulping tank 3 to pump the slurry inside the tank into the transfer tank 5 of the front-end wet process workshop for pressure filtration and washing.

[0015] The beating tank 3 is equipped with a water inlet 6 for supplying a certain amount of pure water to the tank. The side wall is equipped with a liquid level gauge 8 for displaying the liquid content in the tank, a slurry solids content detector 7 for monitoring the solids content of the slurry in the tank, and a circulation device 9 to increase the uniformity of the internal slurry mixing. The circulation device 9 uses a transfer pump 4 to pump the slurry from the bottom of the tank to the top for uniform mixing. A flow meter 10 is installed between the transfer pump 4 and the transfer tank 5 to monitor the amount of slurry pumped from the beating tank 3 into the transfer tank 5.

[0016] When in use, the pulping tank 3 inputs 10m3 of water through the water inlet 6. 3 Pure water and a bag dust removal device 1 collect the iron phosphate tailings containing SO2 and water vapor above the rotary kiln and transport them to the beating tank 3 through the rotary feed valve 2. The stirring device in the tank continuously stirs the slurry. The delivery pump 4 is turned on, and at the same time, the valve of the circulation device 9 is opened to transport the slurry at the bottom of the tank to the top of the tank to increase the mixing uniformity of the slurry. The liquid level changes in the beating tank 3 are observed by the liquid level gauge 8 on the side wall of the beating tank 3, and the detection data of the solid content detector 7 are reviewed. When the solid content reaches about 10%, the valve of the circulation device 9 is closed, and the valve for transporting the mixed slurry is opened to transport the slurry in the tank to the transfer tank 5 of the front-stage wet process workshop for filter pressing and washing. After being pressed into filter cakes, the recycled filter cakes and normal filter cakes are put into the next process at a ratio of 1:3.

Claims

1. A device for recovering ferrous phosphate materials, comprising a bag dust removal device (1) connected to a rotary kiln for collecting SO2, water vapor and part of the ferrous phosphate materials inside the kiln, characterized in that: A pulping tank (3) for making slurry from the tailings collected by the bag dust removal device (1) and a delivery pump (4) for pumping the slurry in the pulping tank (3) into a transfer tank (5) in the front-stage wet process workshop for filter pressing and washing are provided below the bag dust removal device (1).

2. The iron phosphate material recovery device according to claim 1, characterized in that: A rotary feeding valve (2) is provided between the bag dust removal device (1) and the beating tank (3) to prevent tailings from adhering to the bag dust removal device (1) and causing blockage.

3. The recovery device for iron phosphate material according to claim 1, characterized in that: The beating tank (3) is provided with a water inlet (6) for providing a certain amount of pure water into the tank.

4. The ferric phosphate material recovery device according to claim 1 or 3, characterized in that: The beating tank (3) is provided with a circulation device (9) for increasing the mixing uniformity of the internal slurry.

5. The recovery device for iron phosphate material according to claim 4, characterized in that: The circulation device (9) comprises a delivery pump (4) for pumping the slurry at the bottom of the beating tank (3) into the top.

6. The ferric phosphate material recovery device according to claim 1 or 3, characterized in that: The side wall of the beating tank (3) is provided with a liquid level meter (8) for displaying the liquid content in the tank.

7. The ferric phosphate material recovery device according to claim 1 or 3, characterized in that: The beating tank (3) is provided with a slurry solid content detector (7) for monitoring the solid content of the slurry in the tank.

8. The ferric phosphate material recovery device according to claim 1, characterized in that: A flow meter (10) is provided between the delivery pump (4) and the transfer tank (5) for monitoring the amount of slurry in the beating tank (3) pumped into the transfer tank (5).

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