An apparatus and method for preparing iron phosphate from waste batteries

Abstract

This invention relates to the field of waste battery recycling and discloses an apparatus and method for preparing iron phosphate using waste batteries. The apparatus includes an acid leaching tank, a filtrate removal tank, a synthesis tank, and an aging crystallization tank connected in sequence. The acid leaching tank has a material lifting pipe, a sulfuric acid pump, and a water supply pump connected to its side. After acid leaching, the solution flows into a pressurized channel one of the tank body through the connecting pipe. The liquid then rises to a temporary storage chamber one. The lower end of the temporary storage chamber one has an overflow connection hole. When the liquid level reaches a certain height, the liquid flows into a pressurized channel two through the overflow connection hole. In the pressurized channel two, when an electric push rod one drives a pressurized filter element to rise, the filter element covers the port of the overflow connection hole. At this time, the solution in the pressurized channel two leaks downwards into the temporary storage chamber two under pressure, while impurities in the solution are trapped in the pressurized channel two because they cannot pass through the filter holes, achieving efficient separation of the solution and impurities.

Description

Technical Field

[0001] This invention relates to the field of waste battery recycling, specifically to an apparatus and method for preparing iron phosphate from waste batteries. Background Technology

[0002] The preparation of iron phosphate from iron phosphate slag mainly involves acid leaching, pressure filtration, filtrate purification, synthesis, pressure filtration and washing, pulping, aging and crystallization, and pressure filtration and washing. In existing technologies, after leaching iron and phosphorus elements from lithium iron phosphate batteries using acid leaching, the separation of the leachate and tailings is generally carried out using solid-liquid separation. However, this separation method still results in some debris being mixed in the leachate, affecting the purity of the precipitate obtained in subsequent precipitation and crystallization processes. Summary of the Invention

[0003] This invention provides an apparatus and method for preparing iron phosphate using waste batteries, which overcomes the shortcomings described in the background art.

[0004] The technical solution adopted by this invention to solve its technical problem is:

[0005] An apparatus for preparing iron phosphate using waste batteries includes an acid leaching kettle, a filtrate removal kettle, a synthesis kettle, and an aging crystallization kettle connected in sequence. The acid leaching kettle has a material lifting pipe, a sulfuric acid pump, and a water supply pump connected to its side. The material lifting pipe is connected to the side of the acid leaching kettle, while the sulfuric acid pump and the water supply pump are connected to the upper end of the acid leaching kettle. The synthesis kettle has a metering valve connected to its side. The metering valve is connected to the filtrate removal kettle through a third extraction pump, so that the solution in the filtrate removal kettle is drawn to the metering valve and flows into the synthesis kettle for precipitation. The aging crystallization kettle has a feeding port on its surface and a quantitative weighing scale on its side, so that the substance on its surface is added to the aging crystallization kettle through the quantitative weighing scale. The filtrate removal kettle includes a tank body and a pH meter for detecting the acidity and alkalinity in the tank body and a thermometer for detecting the temperature in the tank body. Both the pH meter and the thermometer are inserted into the tank body.

[0006] The tank body is provided with a pressurization channel one, a temporary retention chamber one, a temporary retention chamber two, and a pressurization channel two. The pressurization channel one is connected to the upper end of the temporary retention chamber one, and the pressurization channel two is connected to the upper end of the temporary retention chamber two. The temporary retention chamber one is connected to the pressurization channel two through an overflow connection hole provided at its lower end. The acid leaching kettle is connected to the pressurization channel one through a connecting pipe.

[0007] A pressure filter is installed in the second pressurization channel near the overflow connection port. The pressure filter is driven to rise and fall by an electric push rod. The overflow connection port is connected to the upper part of the second pressurization channel. When the pressure filter descends, the overflow connection port is connected to the second pressurization channel. When the pressure filter rises, it covers the port of the overflow connection port and squeezes the solution in the second pressurization channel, causing the solution to seep down through the pressure filter into the second temporary retention chamber.

[0008] In a preferred embodiment, the pressurized channel 2 is divided into upper and lower solution chambers by a pressurized filter element. The pressurized filter element includes an outer shell and a filter layer and a pressurizing part disposed within the outer shell. The filter layer is connected to the output shaft of the electric push rod 1. A filter chamber is disposed between the filter layer and the pressurizing part. The surface of the pressurizing part is arrayed with conical grooves that gradually deepen from the edge to the center. All pressurizing parts have a reverse osmosis membrane layer at their lower ends. The pressurizing part covers the surface of the reverse osmosis membrane layer. When the electric push rod 1 drives the pressurized filter element to rise, it covers the port and squeezes the solution in the upper solution chamber, causing the solution to permeate through the filter layer, the filter chamber, and the reverse osmosis membrane layer in sequence before flowing into the lower solution chamber.

[0009] A preferred technical solution is that an extraction pump 2 is connected between the overflow connection hole and the pressurization channel 2, so as to extract the solution in the temporary retention chamber 1 into the pressurization channel 2 by the extraction pump 2. When the pressurization filter rises and covers the overflow connection hole port, the extraction pump 2 stops extracting the solution. When the pressurization filter descends, the extraction pump 2 extracts the solution to the surface of the filter layer.

[0010] A preferred technical solution is that a one-way valve is provided in the pressurization channel 1. The high resistance direction of the one-way valve is opposite to the flow direction of the solution in the pressurization channel 1. An inclined surface is provided on the lower side of the inner end of the pressurization channel 1 near the connection end with the temporary retention chamber 1. The inclined surface array has multiple raised slow-flow protrusions.

[0011] A filter element is installed at the connection end between the pressurization channel one and the temporary retention chamber two. A pressurization part one is also provided in the middle of the pressurization channel one. A piston block is provided in the pressurization part one, and the pressurization part one is connected to the outside through a hole. The piston block is driven to rise and fall by an electric push rod two. When the electric push rod two presses the piston block downward, the piston block blocks the hole port and pressurizes the solution between the one-way valve and the filter element, so that the solution seeps from the filter element into the temporary retention chamber one. When the piston block rises, the air in the pressurization part one is discharged to the outside through the hole.

[0012] In a preferred embodiment, the tank body is provided with a through hole, and a float is provided in the temporary holding cavity. The float passes through the through hole from the inside to the outside and extends to the outside of the tank body.

[0013] The float includes a float and an air tube. The fixing block is fixed at the port of the through hole, the float passes through the fixing block, and the float is fixed at the lower end of the air tube. The air tube has a hollow structure, and the lower part of the air tube is connected to the outside through multiple air holes, so that air can flow through the air holes and the inner end of the air tube.

[0014] The filling pad consists of inner and outer rings, which are connected and fixed by multiple connecting pieces. A flow channel for gas flow is formed between two adjacent connecting pieces, and the inner ring surface is provided with ball bearings.

[0015] A method of using the apparatus for preparing iron phosphate from waste batteries, the method comprising the following steps:

[0016] S1: Put the waste batteries that need to be recycled into the acid leaching tank, add sulfuric acid into the acid leaching tank through the sulfuric acid pump, and add water into the acid leaching tank through the sulfuric acid pump. The waste batteries are soaked by sulfuric acid and water to form acid leaching, which leach out the iron and phosphorus elements in the waste batteries.

[0017] S2: The solution formed after acid leaching of waste batteries in the acid leaching kettle is extracted by pump one and transferred to the filtrate removal kettle. The filtrate removal kettle separates the solution and the tailings in the solution, thereby increasing the content of iron and phosphorus in the solution.

[0018] S3: The solution in the filtrate removal vessel is drawn to the metering valve by the extraction pump three, and the iron and phosphorus in the solution are made to exist in the form of a mixture of iron phosphate by adjusting the pH value and temperature.

[0019] S4: The iron phosphate mixture is placed into the quantitative weighing scale and, according to the preset specific weight, into the aging crystallization kettle for precipitation and crystallization. The iron phosphate mixture crystals formed on the inner surface of the aging crystallization kettle are scraped off by the shear pump installed in the aging crystallization kettle.

[0020] A preferred technical solution is that, when separating the solution and the tailings in the solution through the filtrate removal vessel 2, it is necessary to use an electric push rod 24 to squeeze the solution in the pressure channel 211 and to use a pressure filter element 2141 to squeeze the solution in the upper solution chamber of the pressure channel 214 to achieve secondary pressure removal.

[0021] Compared with existing technologies, this technical solution has the following advantages:

[0022] After the acid-leaching solution flows into the pressurized channel one of the tank through the connecting pipe, the liquid will rise into the temporary storage chamber one for temporary storage. The lower end of the temporary storage chamber one is equipped with an overflow connecting hole. When the liquid level reaches a certain height, the liquid will flow into the pressurized channel two through the overflow connecting hole. In the pressurized channel two, when the electric push rod one drives the pressurized filter element to rise, the pressurized filter element will cover the port of the overflow connecting hole. At this time, under the action of pressure, the solution in the pressurized channel two will seep down into the temporary storage chamber two through the fine filter holes of the pressurized filter element. Meanwhile, the impurities in the solution are trapped in the pressurized channel two because they cannot pass through the filter holes, thus achieving efficient separation of solution and impurities.

[0023] When the electric push rod drives the pressure filter to rise, the solution in the pressure channel 2 leaks downward through the pressure filter to the temporary retention chamber 2 under pressure, while impurities are trapped in the pressure channel 2, effectively removing tiny impurities, improving solution purity, and providing a high-quality solution for subsequent processes. Attached Figure Description

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0025] Figure 1 This is an overall diagram of the present invention.

[0026] Figure 2 This is a schematic diagram of a filtrate removal vessel.

[0027] Figure 3 This is a schematic diagram of the second pressurization channel.

[0028] Figure 4 This is a schematic diagram of a pressure filter element.

[0029] Figure 5 This is a schematic diagram of a pressure filter element.

[0030] Figure 6 This is a schematic diagram of the slow-flow protrusion.

[0031] Figure 7 This is a diagram of a float.

[0032] Figure 8 This is a schematic diagram of the filling pad.

[0033] In the diagram: 1. Acid leaching kettle; 11. Material riser pipe; 12. Sulfuric acid pump; 13. Water supply pump; 14. Extraction pump.

[0034] 2. Filtration vessel for removing impurities; 21. Tank body; 22. pH meter; 23. Thermometer; 24. Electric push rod II; 25. Regulating valve; 26. Extraction pump II;

[0035] 211 pressurization channel 1, 212 temporary retention chamber 1, 213 temporary retention chamber 2, 214 pressurization channel 2, 215 through hole;

[0036] One-way valve 2111, pressurizing part 1 2112, filter element 2113, slow-flow protrusion 2114;

[0037] Overflow connection hole 2121, float 2122;

[0038] Pressure filter element 2141, outer shell 1411, filter layer 1412, pressure part 1413, conical groove 1414, reverse osmosis membrane layer 1415, electric push rod 2142;

[0039] Fixed block 1221, float block 1222, air tube 1223, vent 2231, filling pad 1224, flow channel 2241, ball bearing 2242;

[0040] Synthesis reactor 3, metering valve 31, extraction pump 32;

[0041] 4. Aging and crystallization kettle; 41. Quantitative weighing scale. Detailed Implementation

[0042] like Figures 1 to 8 As shown, this invention proposes an apparatus and method for preparing iron phosphate using waste batteries, comprising an acid leaching tank 1, a filtrate removal tank 2, a synthesis tank 3, and an aging and crystallization tank 4 connected in sequence. The acid leaching tank 1 has a material riser 11, a sulfuric acid pump 12, and a water supply pump 13 connected to its side. The material riser 11 is connected to the side of the acid leaching tank 1, while the sulfuric acid pump 12 and the water supply pump 13 are connected to the upper end of the acid leaching tank 1. The synthesis tank 3 has a metering valve 31 connected to its side, and the metering valve 31 is connected to the filtrate removal tank via a pump 32. 2 are connected to each other so that the solution in the filtrate removal vessel 2 can be drawn to the metering valve 31 by the pump 32 and flow into the synthesis vessel 3 for precipitation. The surface of the aging crystallization vessel 4 is provided with a feeding port and the side of the aging crystallization vessel 4 is provided with a metering scale 41 so that the substance on its surface can be put into the aging crystallization vessel 4 by the metering scale 41. The filtrate removal vessel 2 includes a tank 21 and a pH meter 22 for detecting the acidity and alkalinity in the tank 21 and a thermometer 23 for detecting the temperature in the tank 21. The pH meter 22 and the thermometer 23 are both inserted into the tank 21.

[0043] The tank body 21 is provided with a first pressurization channel 211, a first temporary retention chamber 212, a second temporary retention chamber 213, and a second pressurization channel 214. The first pressurization channel 211 is connected to the upper end of the first temporary retention chamber 212, and the second pressurization channel 214 is connected to the upper end of the second temporary retention chamber 213. The first temporary retention chamber 212 is connected to the second pressurization channel 214 through an overflow connection hole 2121 provided at its lower end. The acid leaching kettle 1 is connected to the first pressurization channel 211 through a connecting pipe.

[0044] A pressure filter element 2141 is provided in the second pressurization channel 214 near the overflow connection hole 2121. The pressure filter element 2141 is driven to rise and fall by an electric push rod 2142. The overflow connection hole 2121 is connected to the upper part of the second pressurization channel 214. When the pressure filter element 2141 descends, the overflow connection hole 2121 is connected to the second pressurization channel 214. When the pressure filter element 2141 rises, it covers the port of the overflow connection hole 2121 and squeezes the solution in the second pressurization channel 214, causing the solution to seep downward through the pressure filter element 2141 into the second temporary retention chamber 213.

[0045] After the acid-leaching solution flows into the pressurization channel 211 of the tank 21 through the connecting pipe, the liquid will rise into the temporary storage chamber 212 for temporary storage. The lower end of the temporary storage chamber 212 is provided with an overflow connecting hole 2121. When the liquid level reaches a certain height, the liquid will flow into the pressurization channel 214 through the overflow connecting hole 2121. In the pressurization channel 214, a pressurization filter element 2141 is provided near the port of the overflow connecting hole 2121. When the electric push rod 2142 drives the pressurization filter element 2141 to rise, the pressurization filter element 2141 will cover the port of the overflow connecting hole 2121. At this time, under pressure, the solution in the pressurization channel 214 will seep down into the temporary storage chamber 213 through the fine filter holes of the pressurization filter element 2141. Impurities in the solution are trapped in the pressurization channel 214 because they cannot pass through the filter holes, thus achieving efficient separation of solution and impurities.

[0046] As described above, the second pressurized channel 214 within tank 21 plays a crucial role in the pressurized filtration of impurities in the solution. Its beneficial effects are mainly reflected in the following aspects: First, the second pressurized channel 214, in conjunction with the pressurized filter element 2141 and the electric push rod 2142, can efficiently pressurize and filter the solution flowing into it. When the electric push rod 2142 drives the pressurized filter element 2141 to rise, the solution in the second pressurized channel 214, under pressure, seeps downwards through the pressurized filter element 2141 to the temporary retention chamber 213, while impurities are trapped within the second pressurized channel 214, effectively removing minute impurities, improving solution purity, and providing a high-quality solution for subsequent processes. Second, this filtration method of the second pressurized channel 214 makes the filtration process more stable. The precise control of the electric push rod 2142 ensures smooth lifting and lowering of the pressurized filter element 2141, thereby guaranteeing filtration continuity, which is beneficial for large-scale industrial production and improves overall production efficiency. Third, the filtration operation within the pressurized channel 214 is carried out within the sealed tank 21, preventing the leakage of harmful substances and ensuring a safe production environment. Simultaneously, it reduces wear and tear on subsequent equipment caused by impurities, lowers equipment maintenance costs and frequency, and also reduces the workload of operators. Filtration can be completed simply by controlling the lifting and lowering of the electric push rod 2142, simplifying operation and management.

[0047] The pressurized channel 214 is divided into upper and lower solution chambers by the pressurized filter element 2141. The pressurized filter element 2141 includes an outer shell 1411 and a filter layer 1412 and a pressurized part 1413 disposed inside the outer shell 1411. The filter layer 1412 is connected to the output shaft of the electric push rod 2142. A filter chamber is disposed between the filter layer 1412 and the pressurized part 1413. The surface of the pressurized part 1413 is arrayed with conical grooves 1414 that gradually deepen from the edge to the middle. All pressurized parts 1413 are provided with a reverse osmosis membrane layer 1415 at their lower ends. The pressurized part 1413 covers the surface of the reverse osmosis membrane layer 1415. When the electric push rod 2142 drives the pressurized filter element 2141 to rise, it covers the port of 2121 and squeezes the solution in the upper solution chamber, so that the solution flows through the filter layer 1412, the filter chamber and the reverse osmosis membrane layer 1415 in sequence and then flows into the lower solution chamber.

[0048] The second pressurization channel 214 is divided into upper and lower solution chambers by the pressurization filter element 2141. This structural design brings significant benefits. First, when the pressurization filter element 2141 rises, the upper solution chamber can be initially pressurized and filtered through the synergistic action of the outer shell 1411 and the pressurization part 1413. When the electric push rod 2142 drives the pressurization filter element 2141 to rise, the conical groove 1414 on the surface of the pressurization part 1413 increases the flow path of the solution, making the solution more evenly distributed during pressurization, thereby improving filtration efficiency. The design of the conical groove 1414 makes the flow velocity of the solution slower at the edges and gradually faster in the middle. This change in flow velocity helps the sedimentation and separation of impurities in the solution, further improving the filtration effect.

[0049] Secondly, the lower solution chamber, through the reverse osmosis membrane layer 1415, enables deep filtration of the solution. After passing through the filter layer 1412 and the filter chamber, the solution finally passes through the reverse osmosis membrane layer 1415. This membrane layer effectively removes minute impurities and dissolved solids from the solution, ensuring that the solution flowing into the lower solution chamber has higher purity. This multi-layer filtration structure not only improves the filtration effect of the solution but also extends the service life of the reverse osmosis membrane layer because the upper filter layer 1412 and the pressurization section 1413 can remove most of the impurities beforehand, reducing the burden on the reverse osmosis membrane layer.

[0050] Furthermore, the structural design of the second pressurization channel 214 enhances the stability and controllability of the entire filtration process. Precise control of the electric actuator 2142 ensures smoother lifting and lowering of the pressurized filter element 2141, guaranteeing the continuity and stability of the filtration process. Finally, the layered structure of the upper and lower solution chambers makes the filtration process more efficient and thorough. Through multi-layered filtration and pressurization design, various impurities in the solution can be effectively removed, ensuring the high quality of the final product. This structure not only improves filtration efficiency but also reduces the difficulty of subsequent processing, providing a purer solution for subsequent precipitation and crystallization processes, thereby improving the efficiency of the entire production process and product quality.

[0051] Furthermore, an extraction pump 26 is connected between the overflow connection hole 2121 and the pressurization channel 214 to extract the solution in the temporary chamber 212 into the pressurization channel 214. When the pressurization filter element 2141 rises and covers the port of the overflow connection hole 2121, the extraction pump 26 stops extracting the solution. When the pressurization filter element 2141 descends, the extraction pump 26 extracts the solution to the surface of the filter layer 1412.

[0052] Furthermore, a one-way valve 2111 is provided inside the pressurization channel 211. The high resistance direction of the one-way valve 2111 is opposite to the flow direction of the solution inside the pressurization channel 211. An inclined surface is provided on the lower side of the inner end of the pressurization channel 211 near the connection end with the temporary retention chamber 212. This inclined surface array has multiple raised slow-flow protrusions 2114. A filter element 2113 is provided at the connection end between the pressurization channel 211 and the temporary retention chamber 213. A pressurization section 2112 is also provided in the middle of the pressurization channel 211. A piston block 241 is provided inside the first 2112, and the first 2112 of the pressurizing part is connected to the outside through a hole. The piston block 241 is driven to rise and fall by an electric push rod 24. When the electric push rod 24 pushes the piston block 241 downward, the piston block 241 blocks the hole port and pressurizes the solution between the one-way valve 2111 and the filter element 2113, so that the solution seeps from the filter element 2113 into the temporary chamber 212. When the piston block 241 rises, the air in the first 2112 of the pressurizing part is discharged to the outside through the hole.

[0053] This precise pressurization control ensures that the solution passes evenly through the filter element 2113 under high pressure, improving filtration efficiency. Simultaneously, the design of the pressurization section 2112 makes the pressurization process more stable, avoiding the impact of pressure fluctuations on the filtration effect. Secondly, the filter element 2113 is located at the connection point between the pressurization channel 211 and the temporary retention chamber 213. When the solution passes through the filter element 2113 under high pressure, it can further remove minute impurities and suspended solids from the solution. The selective filtration function of the filter element 2113 ensures that only pure solution flows into the temporary retention chamber 213, thereby improving the purity of the solution. Furthermore, the one-way valve 2111 ensures that the solution can only flow from the pressurization channel 211 to the temporary retention chamber 212, preventing the solution from flowing back to the acid leaching tank 1 during pressurization, thus avoiding the re-introduction of impurities. This unidirectional flow design guarantees the purity of the solution during the pressurized filtration process and improves the processing efficiency of subsequent processes.

[0054] As shown in the figure, a regulating valve 25 is provided above the pressurization channel 211 and is connected to it. Before the solution enters the pressurization channel 211, the entry of the solution can be controlled by the regulating valve 25.

[0055] Furthermore, the shape of the conical protrusion 2115 helps guide impurities in the solution to converge towards the bottom of the chamber, accelerating the sedimentation process. Its sloping surface reduces the adhesion of impurities to the sidewalls and bottom plane of the temporary retention chamber 212, making it easier for impurities to slide to the bottom, thereby improving impurity collection efficiency. This structural design also prevents impurities from forming secondary suspensions within the temporary retention chamber 212, ensuring that the solution is clearer and purer after initial sedimentation, providing better conditions for subsequent filtration and treatment processes.

[0056] Furthermore, the tank body 21 is provided with a through hole 215, and the temporary storage cavity 212 is provided with a float 2122. The float 2122 passes through the through hole 215 from the inside to the outside and extends to the outside of the tank body 21.

[0057] The float 2122 includes 1211, float 1222 and air tube 1223. The fixing block 1221 is fixed at the port of the through hole 215. The float 1222 passes through the fixing block 1221 and is fixed at the lower end of the air tube 1223. The air tube 1223 has a hollow structure and the lower part of the air tube 1223 is connected to the outside through multiple air holes 2231, so that air flows through the air holes 2231 and the inner end of the air tube 1223.

[0058] The filling pad 1224 is composed of inner and outer rings, which are connected and fixed by multiple connecting pieces. A flow channel 2241 for gas flow is formed between two adjacent connecting pieces, and the inner ring surface is provided with ball bearings 2242.

[0059] As can be seen above, the flow channel 2241 provides a smooth flow path for the gas, enabling it to flow efficiently from the inner ring to the outer ring, and then enter the air pipe 1223 through the vent 2231, thereby providing stable buoyancy for the float 1222 and ensuring the normal operation of the float 2122. Secondly, the even distribution of multiple flow channels 2241 helps to achieve uniform gas flow, avoiding gas concentration in a certain area, thus ensuring that the float 1222 is subjected to uniform force and maintaining the stability and reliability of the float 2122.

[0060] A method of using the apparatus for preparing iron phosphate from waste batteries, the method comprising the following steps:

[0061] S1: Put the waste batteries that need to be recycled into the acid leaching tank 1, add sulfuric acid into the acid leaching tank 1 through the sulfuric acid pump 12, and add water into the acid leaching tank 1 through the sulfuric acid pump 12. The waste batteries are soaked by sulfuric acid and water to form acid leaching, and the iron and phosphorus elements in the waste batteries are leached out.

[0062] S2: The solution formed after acid leaching of waste batteries in acid leaching kettle 1 is extracted by pump 14 and transferred to filtrate removal kettle 2. The solution and tailings in the solution are separated by filtrate removal kettle 2 to increase the content of iron and phosphorus in the solution.

[0063] S3: The solution in the filtrate removal vessel 2 is drawn to the metering valve 31 by the pump 32, and the iron and phosphorus in the solution are made to exist in the form of a mixture of iron phosphate by adjusting the pH value and temperature.

[0064] S4: The iron phosphate mixture is placed into the quantitative weighing scale 41, and according to the preset specific weight, the iron phosphate mixture is placed into the aging crystallization tank 4 for precipitation and crystallization. The iron phosphate mixture crystals formed on the inner surface of the aging crystallization tank 4 are scraped off by the shear pump installed in the aging crystallization tank 4.

[0065] A preferred technical solution is that, when separating the solution and the tailings in the solution through the filtrate removal vessel 2, it is necessary to use an electric push rod 24 to squeeze the solution in the pressure channel 211 and to use a pressure filter element 2141 to squeeze the solution in the upper solution chamber of the pressure channel 214 to achieve secondary pressure removal.

[0066] The above description is merely a preferred embodiment of the present invention, and therefore should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made in accordance with the scope of the patent and the contents of the specification should still fall within the scope of the present invention.

Claims

1. An apparatus for preparing iron phosphate using waste batteries, comprising an acid leaching kettle, a filtrate removal kettle, a synthesis kettle, and an aging crystallization kettle connected in sequence. The acid leaching kettle has a material lift pipe, a sulfuric acid pump, and a water supply pump connected to its side. The material lift pipe is connected to the side of the acid leaching kettle, while the sulfuric acid pump and water supply pump are connected to the upper end of the acid leaching kettle. The synthesis kettle has a metering valve connected to its side, which is connected to the filtrate removal kettle via a third extraction pump. The third extraction pump draws the solution from the filtrate removal kettle to the metering valve, which then flows into the synthesis kettle for precipitation. The aging crystallization kettle has a feeding port on its surface and a quantitative weighing scale on its side, which adds substances from its surface into the aging crystallization kettle. The filtrate removal kettle includes a tank body and a pH meter for detecting the acidity / alkalinity inside the tank and a thermometer for detecting the temperature inside the tank. Both the pH meter and the thermometer are inserted into the tank body. The apparatus is characterized by: The tank body is provided with a pressurization channel one, a temporary retention chamber one, a temporary retention chamber two, and a pressurization channel two. The pressurization channel one is connected to the upper end of the temporary retention chamber one, and the pressurization channel two is connected to the upper end of the temporary retention chamber two. The temporary retention chamber one is connected to the pressurization channel two through an overflow connection hole provided at its lower end. The acid leaching kettle is connected to the pressurization channel one through a connecting pipe. A pressure filter is provided in the second pressurization channel near the overflow connection port. The pressure filter is driven to rise and fall by an electric push rod. The overflow connection port is connected to the upper part of the second pressurization channel. When the pressure filter descends, the overflow connection port is connected to the second pressurization channel. When the pressure filter rises, the pressure filter covers the port of the overflow connection port and squeezes the solution in the second pressurization channel, causing the solution to seep down through the pressure filter into the second temporary retention chamber. The second pressurized channel is divided into upper and lower solution chambers by a pressurized filter element. The pressurized filter element includes an outer shell and a filter layer and a pressurizing part disposed within the outer shell. The filter layer is connected to the output shaft of the first electric push rod. A filter chamber is disposed between the filter layer and the pressurizing part. The surface of the pressurizing part is arrayed with conical grooves that gradually deepen from the edge to the center. All pressurizing parts have a reverse osmosis membrane layer at their lower ends. The pressurizing part covers the surface of the reverse osmosis membrane layer. When the first electric push rod drives the pressurized filter element to rise, it covers the port and squeezes the solution in the upper solution chamber, so that the solution flows through the filter layer, the filter chamber and the reverse osmosis membrane layer in sequence and then flows into the lower solution chamber. An extraction pump 2 is connected between the overflow connection hole and the pressurization channel 2 to extract the solution in the temporary retention chamber 1 into the pressurization channel 2. When the pressurization filter rises and covers the overflow connection hole port, the extraction pump 2 stops extracting the solution. When the pressurization filter falls, the extraction pump 2 extracts the solution to the surface of the filter layer. A one-way valve is provided in the pressurization channel 1. The high resistance direction of the one-way valve is opposite to the flow direction of the solution in the pressurization channel 1. An inclined surface is provided on the lower side of the inner end of the pressurization channel 1 near the connection end with the temporary retention chamber 1. The inclined surface array has multiple raised slow-flow protrusions. A filter element is installed at the connection end between the pressurization channel one and the temporary retention chamber two. A pressurization part one is also provided in the middle of the pressurization channel one. A piston block is provided in the pressurization part one, and the pressurization part one is connected to the outside through a hole. The piston block is driven to rise and fall by an electric push rod two. When the electric push rod two presses the piston block downward, the piston block blocks the hole port and pressurizes the solution between the one-way valve and the filter element, so that the solution seeps from the filter element into the temporary retention chamber one. When the piston block rises, the air in the pressurization part one is discharged to the outside through the hole.

2. The apparatus for preparing iron phosphate from waste batteries according to claim 1, characterized in that, The tank body is provided with a through hole, and a float is provided in the temporary holding cavity. The float passes through the through hole from the inside to the outside and extends to the outside of the tank body. The float fixing block includes a float and an air tube. The fixing block is fixed at the port of the through hole, the float passes through the fixing block, and the float is fixed at the lower end of the air tube. The air tube has a hollow structure, and the lower part of the air tube is connected to the outside through multiple air holes, so that air can flow through the air holes and the inner end of the air tube. The filling pad consists of inner and outer rings, which are connected and fixed by multiple connecting pieces. A flow channel for gas flow is formed between two adjacent connecting pieces, and the inner ring surface is provided with ball bearings.

3. A method of using the apparatus for preparing iron phosphate from waste batteries as described in claim 2, characterized in that, The method of use includes the following steps: S1: Put the waste batteries that need to be recycled into the acid leaching tank, add sulfuric acid into the acid leaching tank through the sulfuric acid pump, and add water into the acid leaching tank through the sulfuric acid pump. The waste batteries are soaked by sulfuric acid and water to form acid leaching, which leach out the iron and phosphorus elements in the waste batteries. S2: The solution formed after acid leaching of waste batteries in the acid leaching kettle is extracted by pump one and transferred to the filtrate removal kettle. The filtrate removal kettle separates the solution and the tailings in the solution, thereby increasing the content of iron and phosphorus in the solution. S3: The solution in the filtrate removal vessel is drawn to the metering valve by the extraction pump three, and the iron and phosphorus in the solution are made to exist in the form of a mixture of iron phosphate by adjusting the pH value and temperature. S4: The iron phosphate mixture is placed into the quantitative weighing scale and, according to the preset specific weight, into the aging crystallization kettle for precipitation and crystallization. The iron phosphate mixture crystals formed on the inner surface of the aging crystallization kettle are scraped off by the shear pump installed in the aging crystallization kettle.

4. A method of using the apparatus for preparing iron phosphate from waste batteries as described in claim 3, characterized in that, in, When separating the solution and the tailings in the solution through the filtrate removal kettle, it is necessary to use an electric push rod two to squeeze the solution in the pressure channel one and to use a pressure filter element to squeeze the solution in the upper solution chamber set in the pressure channel two to achieve secondary pressure removal.

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