Continuous washing and filtering system

Abstract

The utility model provides a continuous washing and filtering system and relates to the technical field of iron phosphate preparation. The continuous washing and filtering system comprises a plurality of washing and filtering units which are connected in sequence; each washing and filtering unit comprises a mixer, a booster pump and a cyclone; the mixer is provided with a slurry inlet, a washing water inlet and a mixed slurry outlet, the mixed slurry outlet is connected with the swirler through the booster pump, and an underflow port of the swirler is connected with the slurry inlet of the mixer of the adjacent washing and filtering unit. The plurality of washing and filtering units of the continuous washing and filtering system can continuously wash the slurry of the iron phosphate dihydrate in sequence, so that the washing uniformity is improved, the problem of non-uniform washing in the existing intermittent washing mode can be solved, the problems of short circuit and incomplete enrichment and washing when a kettle is used for continuous washing can be solved, and the production efficiency is improved. Therefore, the uniformity and the consistency of iron phosphate products are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of iron phosphate preparation, in particular to a continuous washing and filtering system. Background Art

[0002] With the popularization of new energy vehicles, the research on power batteries has become one of the hot topics. The precursors of power batteries are represented by ternary and lithium iron phosphate. High-nickel series ternary precursors are popular because of their high capacity, high tap density, fast charge and discharge, and long endurance, but their safety problems have become a major problem. Therefore, lithium iron phosphate materials with good safety performance, long cycle life, low cost and other advantages have gradually attracted people's attention and are expected to have a broader application prospect in the field of energy storage batteries in the future.

[0003] Iron phosphate is the most important synthetic raw material for lithium iron phosphate. In the process of preparing iron phosphate, it is necessary to wash and filter the obtained iron phosphate dihydrate to remove impurities.

[0004] At present, the conventional washing method is to use a plate filter press for intermittent multi-stage washing kettle series beating and washing after pressure filtration, or intermittent on-line washing in the plate filter press, which has the problems of uneven washing among batches due to uneven distribution among filter cakes and uneven washing between batches due to fluctuations in washing pressure, water volume, etc. Summary of the Utility Model

[0005] In order to solve the problem of uneven washing in the existing intermittent washing method, the purpose of the utility model is to provide a continuous washing and filtering system.

[0006] The utility model provides the following technical solutions:

[0007] A continuous washing and filtering system includes a plurality of sequentially connected washing and filtering units, and each washing and filtering unit includes a mixer, a booster pump and a hydrocyclone;

[0008] The mixer has a slurry inlet, a washing water inlet and a mixed slurry outlet. The mixed slurry outlet is connected to the hydrocyclone through the booster pump, and the underflow port of the hydrocyclone is connected to the slurry inlet of the mixer of the adjacent washing and filtering unit.

[0009] As a further optional solution to the continuous washing and filtering system, each washing and filtering unit further includes a thickener. The overflow port of the hydrocyclone is connected to the thickener, and the discharge port of the thickener is connected to the slurry inlet of the mixer of the adjacent washing and filtering unit.

[0010] As a further optional solution to the continuous washing and filtering system, the number of the washing and filtering units is N, and N is an integer not less than 3.

[0011] As a further optional solution for the continuous washing and filtering system, the overflow port of the thickener of the nth washing and filtering unit is connected to the washing water inlet of the mixer of the (n - 1)th washing and filtering unit, where n is an integer and 1 < n ≤ N.

[0012] As a further optional solution for the continuous washing and filtering system, the slurry inlet of the mixer of the first washing and filtering unit is connected to the reaction kettle.

[0013] As a further optional solution for the continuous washing and filtering system, the continuous washing and filtering system further includes a delivery pump. The underflow port of the hydrocyclone of the last washing and filtering unit is connected to the delivery pump, and the discharge port of the thickener of the last washing and filtering unit is connected to the delivery pump.

[0014] As a further optional solution for the continuous washing and filtering system, the washing and filtering unit further includes a turbidimeter. The turbidimeter is arranged between the overflow port of the hydrocyclone and the thickener, and the turbidimeter is electrically connected to the booster pump.

[0015] As a further optional solution for the continuous washing and filtering system, the mixer is a mixing pump.

[0016] As a further optional solution for the continuous washing and filtering system, the washing and filtering unit includes a first washing and filtering unit, a second washing and filtering unit, a third washing and filtering unit, and a fourth washing and filtering unit;

[0017] The first washing and filtering unit includes a first mixer, a first booster pump, and a first hydrocyclone. The first mixer has a first slurry inlet, a first washing water inlet, and a first mixed slurry outlet. The first mixed slurry outlet is connected to the first hydrocyclone through the first booster pump;

[0018] The second washing and filtering unit includes a second mixer, a second booster pump, and a second hydrocyclone. The second mixer has a second slurry inlet, a second washing water inlet, and a second mixed slurry outlet. The second slurry inlet is connected to the underflow port of the first hydrocyclone, and the second mixed slurry outlet is connected to the second hydrocyclone through the second booster pump;

[0019] The third washing and filtering unit includes a third mixer, a third booster pump, and a third hydrocyclone. The third mixer has a third slurry inlet, a third washing water inlet, and a third mixed slurry outlet. The third slurry inlet is connected to the underflow port of the second hydrocyclone, and the third mixed slurry outlet is connected to the third hydrocyclone through the third booster pump;

[0020] The fourth washing and filtering unit includes a fourth mixer, a fourth booster pump, and a fourth cyclone. The fourth mixer has a fourth slurry inlet, a fourth washing water inlet, and a fourth mixed slurry outlet. The fourth slurry inlet is connected to the underflow port of the third cyclone, and the fourth mixed slurry outlet is connected to the fourth cyclone through the fourth booster pump.

[0021] As a further optional solution to the continuous washing and filtering system, the first washing and filtering unit further includes a first thickener. The overflow port of the first cyclone is connected to the first thickener, and the discharge port of the first thickener is connected to the second slurry inlet.

[0022] The second washing and filtering unit further includes a second thickener. The overflow port of the second cyclone is connected to the second thickener, the discharge port of the second thickener is connected to the third slurry inlet, and the overflow port of the second thickener is connected to the first washing water inlet.

[0023] The third washing and filtering unit further includes a third thickener. The overflow port of the third cyclone is connected to the third thickener, the discharge port of the third thickener is connected to the fourth slurry inlet, and the overflow port of the third thickener is connected to the second washing water inlet.

[0024] The fourth washing and filtering unit further includes a fourth thickener. The overflow port of the fourth cyclone is connected to the fourth thickener, and the overflow port of the fourth thickener is connected to the third washing water inlet.

[0025] The embodiments of the present utility model have the following beneficial effects:

[0026] In the above continuous washing and filtering system, the mixed slurry outlet of the mixer is connected to the hydrocyclone through a booster pump, and the underflow port of the hydrocyclone is connected to the slurry inlet of the mixer of the adjacent washing and filtering unit, so that multiple washing and filtering units are connected in sequence. Taking the washing of ferric phosphate dihydrate as an example, in use, the slurry of ferric phosphate dihydrate enters the mixer from the slurry inlet, and the washing water enters the mixer from the washing water inlet. The slurry of ferric phosphate dihydrate and the washing water are sheared and mixed at high speed in the mixer to form a mixed slurry, and the impurities in the ferric phosphate dihydrate are dissolved in the washing water. After the mixed slurry is pressurized by the booster pump and then transported into the hydrocyclone, the ferric phosphate dihydrate and the washing water are separated under the action of centrifugal force, so as to be separated from the impurities dissolved in the washing water, realizing the washing of ferric phosphate dihydrate, and the washed slurry separated enters the mixer of the next washing and filtering unit. Thus, the high-speed shearing of the mixer increases the mass transfer effect of the washing process, promotes the full contact and ion exchange between the washing water and the ferric phosphate dihydrate, and can reduce the soluble impurities adsorbed on the surface of the ferric phosphate dihydrate, ensuring the uniformity of the washing of ferric phosphate dihydrate. The slurry of ferric phosphate dihydrate is continuously washed through multiple washing and filtering units in sequence, improving the washing uniformity, being able to solve the problem of uneven washing existing in the existing intermittent washing method, as well as the problems of short circuit and incomplete washing due to enrichment during continuous washing in a kettle, thereby improving the uniformity and consistency of the ferric phosphate product.

[0027] In order to make the above objects, features, and advantages of the present utility model more obvious and understandable, the following specifically gives preferred embodiments and, in conjunction with the accompanying drawings, makes the following detailed descriptions. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following will briefly introduce the drawings required to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present utility model, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0029] Figure 1 Shows the overall structural schematic diagram of a continuous washing and filtering system provided by an embodiment of the present utility model;

[0030] Figure 2 Shows the structural schematic diagram of a washing and filtering unit in a continuous washing and filtering system provided by an embodiment of the present utility model;

[0031] Figure 3 Shows the structural schematic diagram of a continuous washing and filtering system in a specific embodiment provided by an embodiment of the present utility model.

[0032] MAIN ELEMENT SYMBOL DESCRIPTION:

[0033] 100 - Washing and filtering unit; 110 - Mixer; 111 - Slurry inlet; 112 - Washing water inlet; 113 - Mixed slurry outlet; 120 - Booster pump; 130 - Hydrocyclone; 140 - Thickener; 150 - Turbidimeter; 200 - Transfer pump;

[0034] 100a - First washing and filtering unit; 110a - First mixer; 111a - First slurry inlet; 112a - First washing water inlet; 113a - First mixed slurry outlet; 120a - First booster pump; 130a - First hydrocyclone; 140a - First thickener; 100b - Second washing and filtering unit; 110b - Second mixer; 111b - Second slurry inlet; 112b - Second washing water inlet; 113b - Second mixed slurry outlet; 120b - Second booster pump; 130b - Second hydrocyclone; 140b - Second thickener; 100c - Third washing and filtering unit; 110c - Third mixer; 111c - Third slurry inlet; 112c - Third washing water inlet; 113c - Third mixed slurry outlet; 120c - Third booster pump; 130c - Third hydrocyclone; 140c - Third thickener; 100d - Fourth washing and filtering unit; 110d - Fourth mixer; 111d - Fourth slurry inlet; 112d - Fourth washing water inlet; 113d - Fourth mixed slurry outlet; 120d - Fourth booster pump; 130d - Fourth hydrocyclone; 140d - Fourth thickener. Detailed implementation manners

[0035] The embodiments of the present utility model will be described in detail below. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary only for explaining the present utility model and should not be construed as a limitation to the present utility model.

[0036] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. On the contrary, when an element is referred to as being "directly on" another element, there is no intermediate element. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0037] In the present utility model, unless otherwise clearly defined and limited, the terms "installation", "connection", "linkage", "fixation", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral body; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0038] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, "a plurality of" means two or more unless otherwise specifically and clearly defined.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used in the specification of the template herein are only for the purpose of describing specific embodiments and are not intended to limit the present utility model. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0040] Embodiment

[0041] This embodiment provides a continuous washing and filtering system (hereinafter referred to as "washing and filtering system" for short), which is used for washing and filtering materials such as ferric phosphate dihydrate and ammonium iron hydroxyphosphate. The following takes ferric phosphate dihydrate as an example for illustration.

[0042] Please refer to Figure 1 , the washing and filtering system includes a plurality of washing and filtering units 100 connected in sequence. Each washing and filtering unit 100 includes a mixer 110, a booster pump 120, and a hydrocyclone 130.

[0043] Please combine Figure 2 , wherein, the mixer 110 has a slurry inlet 111, a washing water inlet 112, and a mixed slurry outlet 113. The mixed slurry outlet 113 is connected to the hydrocyclone 130 through the booster pump 120. The underflow port of the hydrocyclone 130 is connected to the slurry inlet 111 of the mixer 110 of the adjacent washing and filtering unit 100, so that a plurality of washing and filtering units 100 are connected in sequence.

[0044] When using the above washing and filtering system, the slurry of iron phosphate dihydrate enters the mixer 110 from the slurry inlet 111, and the washing water enters the mixer 110 from the washing water inlet 112. The slurry of iron phosphate dihydrate and the washing water are sheared and mixed at high speed in the mixer 110 to form a mixed slurry, and the impurities in the iron phosphate dihydrate are dissolved in the washing water. After the mixed slurry is pressurized by the booster pump 120 and then transported into the cyclone 130, the iron phosphate dihydrate and the washing water are separated under the action of centrifugal force, so as to be separated from the impurities dissolved in the washing water, realizing the washing of iron phosphate dihydrate, and the washed slurry separated enters the mixer 110 of the next washing and filtering unit 100.

[0045] Thus, the high-speed shearing of the mixer 110 increases the mass transfer effect of the washing process, promotes the full contact and ion exchange between the washing water and the iron phosphate dihydrate, and can reduce the soluble impurities adsorbed on the surface of the iron phosphate dihydrate, ensuring the uniformity of the washing of the iron phosphate dihydrate. The slurry of iron phosphate dihydrate is continuously washed through multiple washing and filtering units 100 in sequence, improving the washing uniformity, and can solve the problem of uneven washing existing in the existing intermittent washing method, as well as the problems of short circuit and incomplete washing due to enrichment when continuous washing is carried out in a kettle, thereby improving the uniformity and consistency of the iron phosphate product.

[0046] In some embodiments, the mixer 110 uses a mixing pump.

[0047] After the slurry of iron phosphate dihydrate and the washing water enter the mixing pump, they are cut into countless small washing units under the high-speed shearing action of the mixing pump to form a mixed slurry, increasing the mass transfer effect of the washing process, promoting the full contact and ion exchange between the washing water and the iron phosphate dihydrate, and at the same time can reduce the soluble impurities adsorbed on the surface of the iron phosphate dihydrate, ensuring the uniformity of the washing of the iron phosphate dihydrate.

[0048] In some embodiments, the slurry inlet 111 of the mixer 110 of the first washing and filtering unit 100 is connected to a reaction kettle.

[0049] Exemplarily, the reaction kettle is a crystal growth tank, and the slurry inlet 111 of the mixer 110 of the first washing and filtering unit 100 is connected to the overflow port of the crystal growth tank.

[0050] During operation, the crystalline iron phosphate dihydrate further agglomerates in the crystal growth tank. By adjusting the stirring speed and residence time, iron phosphate dihydrate meeting the particle size requirements is formed and continuously overflows into the mixer 110 of the first washing and filtering unit 100.

[0051] In some embodiments, the above continuous washing and filtering system further includes a delivery pump 200, and the underflow port of the cyclone 130 of the last washing and filtering unit 100 is connected to the delivery pump 200.

[0052] The washed slurry discharged from the underflow port of the hydrocyclone 130 of the last washing and filtering unit 100 is the dihydrate iron phosphate slurry that has been fully washed and filtered. It is transported to the drying, sintering, and packaging system through the transfer pump 200 for subsequent processing.

[0053] Furthermore, each washing and filtering unit 100 also includes a thickener 140. The overflow port of the hydrocyclone 130 is connected to the thickener 140, and the discharge port of the thickener 140 is connected to the slurry inlet 111 of the mixer 110 of the adjacent washing and filtering unit 100.

[0054] Specifically, the overflow port of the hydrocyclone 130 is connected to the central cylinder of the thickener 140. After the discharge port of the thickener 140 is merged with the underflow port of the hydrocyclone 130, it is connected to the slurry inlet 111 of the mixer 110 of the adjacent washing and filtering unit 100.

[0055] When the dihydrate iron phosphate and the washing water in the hydrocyclone 130 are separated under the action of centrifugal force, the clear liquid is discharged from the overflow port to the thickener 140. This clear liquid is mainly the washing water dissolved with impurities, and at the same time, it is mixed with a small amount of dihydrate iron phosphate. The thickener 140 concentrates the dihydrate iron phosphate in this clear liquid, and the concentrated dihydrate iron phosphate is discharged from the discharge port of the thickener 140 to the mixer 110 of the adjacent washing and filtering unit 100, thereby realizing the recovery of this part of the dihydrate iron phosphate.

[0056] Particularly, after the discharge port of the thickener 140 of the last washing and filtering unit 100 is merged with the underflow port of the hydrocyclone 130 of the last washing and filtering unit 100, it is connected to the transfer pump 200.

[0057] Furthermore, each washing and filtering unit 100 also includes a turbidimeter 150. The turbidimeter 150 is arranged between the overflow port of the hydrocyclone 130 and the thickener 140, and the turbidimeter 150 is electrically connected to the booster pump 120.

[0058] During use, the turbidimeter 150 is interlocked with the motor frequency of the booster pump 120. When the turbidimeter 150 detects that the turbidity of the clear liquid overflowing from the hydrocyclone 130 is too high, it indicates that the dihydrate iron phosphate in the hydrocyclone 130 is not well separated from the washing water, resulting in more dihydrate iron phosphate mixed in the clear liquid. At this time, the turbidimeter 150 outputs a signal to the motor controller of the booster pump 120 to increase the motor frequency, so that the pressure of the booster pump 120 increases, and then the mixed slurry flows into the hydrocyclone 130 at a faster speed, enhancing the centrifugal separation effect of the hydrocyclone 130, and finally achieving the purpose of reducing the dihydrate iron phosphate mixed in the clear liquid.

[0059] In some embodiments, the number of the washing and filtering units 100 is N, and N is an integer not less than 3.

[0060] Optionally, N can be 3, 4, 5, 6, or any integer not less than 3.

[0061] During use, the iron phosphate slurry is washed and filtered through at least three stages to ensure the washing effect and meet the process requirements of subsequent processes.

[0062] Preferably, N ≥ 4.

[0063] Further, the overflow port of the thickener 140 of the nth washing and filtering unit 100 is connected to the washing water inlet 112 of the mixer 110 of the (n - 1)th washing and filtering unit 100, where n is an integer and 1 < n ≤ N.

[0064] Taking n = 2 as an example, the clear liquid overflowing from the overflow port of the thickener 140 of the second washing and filtering unit 100 is the impurity solution after washing the dihydrate iron phosphate slurry twice. Its impurity content is less than that of the impurity solution after washing the dihydrate iron phosphate slurry once, and there is a certain concentration gradient. Therefore, it can be used as the washing water for washing the dihydrate iron phosphate slurry once to save water resources and reduce the washing water consumption.

[0065] In summary, the multiple washing and filtering units 100 of the above continuous washing and filtering system can successively wash the slurry of dihydrate iron phosphate continuously, improving the washing uniformity, and can solve the problems of uneven washing existing in the existing intermittent washing method and the problems of short circuit and incomplete enrichment washing when using a kettle for continuous washing, thereby improving the uniformity and consistency of the iron phosphate product.

[0066] In related technologies, there is also a method of continuously washing the iron phosphate slurry using a centrifuge. However, the centrifuge requires a large site, and the operation process of the centrifuge has high energy consumption, large vibration, and has a certain impact on the environment.

[0067] In contrast, the equipment used in the above washing and filtering system are all static equipment, and the energy consumption is lower than that of dynamic equipment such as centrifuges.

[0068] In related technologies, there is also a method of continuously washing the iron phosphate slurry using a membrane washing device. However, the membrane washing device is extremely prone to clogging, the production efficiency is not high, and the cost of self-cleaning and replacement of the membrane is high.

[0069] In contrast, the above washing and filtering system is easy to maintain and repair, and can avoid problems such as material blockage and short equipment operation life caused by the membrane washing device.

[0070] In the related art, there is also a method of continuously washing iron phosphate slurry using a washing kettle. The specific operation method is to feed, add washing water, and stir simultaneously, while continuously discharging the washed slurry. However, this method has problems such as short-circuiting of the slurry and washing water. It is possible that the newly added slurry is discharged with the washed slurry without being fully washed. At the same time, there are also problems such as uneven stirring resulting in the enrichment of impurities in the washing kettle, and insufficient stirring intensity resulting in the entrapment of impurities by the material, which affect the washing effect.

[0071] In contrast, the slurry continuously enters and exits the above washing and filtering system, with a short residence time. The newly added slurry is not likely to contaminate the washed slurry, improving the short-circuit situation of the slurry and washing water.

[0072] Please refer to Figure 3 , in this embodiment, the washing and filtering unit 100 includes a first washing and filtering unit 100a, a second washing and filtering unit 100b, a third washing and filtering unit 100c, and a fourth washing and filtering unit 100d.

[0073] Among them, the first washing and filtering unit 100a includes a first mixer 110a, a first booster pump 120a, and a first cyclone 130a. The first mixer 110a has a first slurry inlet 111a, a first washing water inlet 112a, and a first mixed slurry outlet 113a. The first mixed slurry outlet 113a is connected to the first cyclone 130a through the first booster pump 120a.

[0074] As described above, the first mixer 110a uses a mixing pump. In addition, the first slurry inlet 111a is connected to the overflow port of the crystal-growing tank.

[0075] During operation, the first mixer 110a continuously sucks in the slurry of dihydrate iron phosphate overflowing from the crystal-growing tank and washing water from other sources. Under the high-speed shearing action of the first mixer 110a, the slurry of dihydrate iron phosphate and the washing water are cut into countless small washing units to form a mixed slurry A, increasing the mass transfer effect during the washing process. The mixed slurry A is continuously transported into the first booster pump 120a, avoiding the problems of short-circuiting of dihydrate iron phosphate and washing water during the continuous washing process of the traditional washing kettle. At the same time, it avoids the disadvantages that uneven stirring leads to the enrichment of impurities in the washing kettle and insufficient stirring intensity leads to the entrapment of impurities by the material, which affect the washing effect.

[0076] The mixed slurry A is pressurized by the first booster pump 120a and then transported into the first hydrocyclone 130a. In the first hydrocyclone 130a, due to the different specific gravities of the washing water and iron dihydrate phosphate, separation occurs under the action of centrifugal force. The clear liquid is discharged from the overflow port of the first hydrocyclone 130a, and the washed slurry A containing iron dihydrate phosphate is discharged from the underflow port of the first hydrocyclone 130a. The continuous separation of the mixed slurry A in the first hydrocyclone 130a avoids the problems of material accumulation and impurity enrichment in the traditional washing kettle.

[0077] Similarly, the second washing and filtering unit 100b includes a second mixer 110b, a second booster pump 120b, and a second hydrocyclone 130b. The second mixer 110b has a second slurry inlet 111b, a second washing water inlet 112b, and a second mixed slurry outlet 113b. The second slurry inlet 111b is connected to the underflow port of the first hydrocyclone 130a, and the second mixed slurry outlet 113b is connected to the second hydrocyclone 130b through the second booster pump 120b.

[0078] As mentioned above, the second mixer 110b also uses a mixing pump.

[0079] During operation, the second mixer 110b continuously sucks in the washed slurry A and the washing water from other sources. Under the high-speed shearing action of the second mixer 110b, the washed slurry A and the washing water are cut into countless small washing units to form a mixed slurry B, increasing the mass transfer effect during the washing process. The mixed slurry B is continuously transported into the second booster pump 120b, avoiding the problems of short-circuit of iron dihydrate phosphate and washing water during the continuous washing process in the traditional washing kettle, and at the same time avoiding the disadvantages that affect the washing effect, such as impurity enrichment in the washing kettle due to uneven stirring and material wrapping impurities due to insufficient stirring intensity.

[0080] The mixed slurry B is pressurized by the second booster pump 120b and then transported into the second hydrocyclone 130b. In the second hydrocyclone 130b, due to the different specific gravities of the washing water and iron dihydrate phosphate, separation occurs under the action of centrifugal force. The clear liquid is discharged from the overflow port of the second hydrocyclone 130b, and the washed slurry B containing iron dihydrate phosphate is discharged from the underflow port of the second hydrocyclone 130b. The continuous separation of the mixed slurry B in the second hydrocyclone 130b avoids the problems of material accumulation and impurity enrichment in the traditional washing kettle.

[0081] Similarly, the third washing and filtering unit 100c includes a third mixer 110c, a third booster pump 120c, and a third hydrocyclone 130c. The third mixer 110c has a third slurry inlet 111c, a third washing water inlet 112c, and a third mixed slurry outlet 113c. The third slurry inlet 111c is connected to the underflow port of the second hydrocyclone 130b, and the third mixed slurry outlet 113c is connected to the third hydrocyclone 130c through the third booster pump 120c.

[0082] As described above, the third mixer 110c also uses a mixing pump.

[0083] During operation, the third mixer 110c continuously sucks in the washed slurry B and wash water from other sources. Under the high-speed shearing action of the third mixer 110c, the washed slurry B and the wash water are cut into countless small washing units to form a mixed slurry C, which increases the mass transfer effect during the washing process. The mixed slurry C is continuously conveyed into the third booster pump 120c, avoiding the problems of short-circuit of dihydrate ferric phosphate and wash water in the continuous washing process of the traditional washing kettle, and at the same time avoiding the disadvantages that affect the washing effect, such as the enrichment of impurities in the washing kettle due to uneven stirring and the wrapping of impurities by materials due to insufficient stirring intensity.

[0084] The mixed slurry C is pressurized by the third booster pump 120c and then conveyed into the third cyclone 130c. In the third cyclone 130c, due to the different specific gravities of the wash water and dihydrate ferric phosphate, the mixed slurry C is separated under the action of centrifugal force. The clear liquid is discharged from the overflow port of the third cyclone 130c, and the washed slurry C containing dihydrate ferric phosphate is discharged from the underflow port of the third cyclone 130c. The mixed slurry C is continuously separated in the third cyclone 130c, avoiding the problems of material accumulation and impurity enrichment in the traditional washing kettle.

[0085] Similarly, the fourth washing and filtering unit 100d includes a fourth mixer 110d, a fourth booster pump 120d, and a fourth cyclone 130d. The fourth mixer 110d has a fourth slurry inlet 111d, a fourth wash water inlet 112d, and a fourth mixed slurry outlet 113d. The fourth slurry inlet 111d is connected to the underflow port of the third cyclone 130c, and the fourth mixed slurry outlet 113d is connected to the fourth cyclone 130d through the fourth booster pump 120d.

[0086] As described above, the fourth mixer 110d also uses a mixing pump.

[0087] During operation, the fourth mixer 110d continuously sucks in the washed slurry C and wash water from other sources. Under the high-speed shearing action of the fourth mixer 110d, the washed slurry C and the wash water are cut into countless small washing units to form a mixed slurry D, which increases the mass transfer effect during the washing process. The mixed slurry A is continuously conveyed into the fourth booster pump 120d, avoiding the problems of short-circuit of dihydrate ferric phosphate and wash water in the continuous washing process of the traditional washing kettle, and at the same time avoiding the disadvantages that affect the washing effect, such as the enrichment of impurities in the washing kettle due to uneven stirring and the wrapping of impurities by materials due to insufficient stirring intensity.

[0088] The mixed slurry D is pressurized by the fourth booster pump 120d and then transported into the fourth hydrocyclone 130d. In the fourth hydrocyclone 130d, due to the different specific gravities of the washing water and iron dihydrate phosphate, separation occurs under the action of centrifugal force. The clear liquid is discharged from the overflow port of the fourth hydrocyclone 130d, and the washed slurry D containing iron dihydrate phosphate is discharged from the underflow port of the fourth hydrocyclone 130d. The continuous separation of the mixed slurry D in the fourth hydrocyclone 130d avoids the problems of material accumulation and impurity enrichment in the traditional washing kettle.

[0089] Furthermore, the first washing and filtering unit 100a further includes a first thickener 140a. The overflow port of the first hydrocyclone 130a is connected to the first thickener 140a, and the discharge port of the first thickener 140a is connected to the second slurry inlet 111b.

[0090] During operation, the clear liquid discharged from the overflow port of the first hydrocyclone 130a enters the first thickener 140a and is concentrated by the first thickener 140a. The iron dihydrate phosphate obtained by concentration is discharged from the discharge port of the first thickener 140a, merged with the iron dihydrate phosphate discharged from the underflow port of the first hydrocyclone 130a to form the washed slurry A, and then enters the second mixer 110b. In addition, the overflow liquid from the overflow port of the first thickener 140a is discharged from the system.

[0091] Similarly, the second washing and filtering unit 100b further includes a second thickener 140b. The overflow port of the second hydrocyclone 130b is connected to the second thickener 140b, the discharge port of the second thickener 140b is connected to the third slurry inlet 111c, and the overflow port of the second thickener 140b is connected to the first washing water inlet 112a.

[0092] During operation, the clear liquid discharged from the overflow port of the second hydrocyclone 130b enters the second thickener 140b and is concentrated by the second thickener 140b. The iron dihydrate phosphate obtained by concentration is discharged from the discharge port of the second thickener 140b, merged with the iron dihydrate phosphate discharged from the underflow port of the second hydrocyclone 130b to form the washed slurry B, and then enters the third mixer 110c. In addition, the clear liquid overflowing from the overflow port of the second thickener 140b is sucked into the first mixer 110a as washing water.

[0093] Similarly, the third washing and filtering unit 100c further includes a third thickener 140c. The overflow port of the third hydrocyclone 130c is connected to the third thickener 140c, the discharge port of the third thickener 140c is connected to the fourth slurry inlet 111d, and the overflow port of the third thickener 140c is connected to the second washing water inlet 112b.

[0094] During operation, the clear liquid discharged from the overflow port of the third cyclone 130c enters the third thickener 140c and is concentrated by the third thickener 140c. The iron phosphate dihydrate obtained by concentration is discharged from the discharge port of the third thickener 140c, merged with the iron phosphate dihydrate discharged from the underflow port of the third cyclone 130c to form the washed slurry C, and then enters the fourth mixer 110d. In addition, the clear liquid overflowing from the overflow port of the third thickener 140c is sucked into the second mixer 110b as washing water.

[0095] Similarly, the fourth washing and filtering unit 100d further includes a fourth thickener 140d. The overflow port of the fourth cyclone 130d is connected to the fourth thickener 140d, and the overflow port of the fourth thickener 140d is connected to the third washing water inlet 112c.

[0096] During operation, the clear liquid discharged from the overflow port of the fourth cyclone 130d enters the fourth thickener 140d and is concentrated by the fourth thickener 140d. The iron phosphate dihydrate obtained by concentration is discharged from the discharge port of the fourth thickener 140d, merged with the iron phosphate dihydrate discharged from the underflow port of the fourth cyclone 130d to form the washed slurry D, and then is transported to the drying, sintering, and packaging system by a transfer pump for subsequent processing. In addition, the clear liquid overflowing from the overflow port of the fourth thickener 140d is sucked into the third mixer 110c as washing water.

[0097] In all the examples shown and described here, any specific value should be construed as merely exemplary, not as a limitation. Therefore, other examples of the exemplary embodiments may have different values.

[0098] It should be noted that like reference numerals and letters denote like items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0099] The above-described embodiments merely represent several implementation manners of the present utility model. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the present utility model. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present utility model, several modifications and improvements can still be made, and these all belong to the protection scope of the present utility model.

Claims

1. A continuous washing and filtration system, characterized in that, It includes multiple sequentially connected washing and filtering units, and each washing and filtering unit includes a mixer, a booster pump, and a hydrocyclone; The mixer has a slurry inlet, a washing water inlet, and a mixed slurry outlet. The mixed slurry outlet is connected to the hydrocyclone through the booster pump, and the underflow port of the hydrocyclone is connected to the slurry inlet of the mixer of the adjacent washing and filtering unit.

2. The continuous washing and filtration system according to claim 1, wherein The washing and filtering unit further includes a thickener. The overflow port of the hydrocyclone is connected to the thickener, and the discharge port of the thickener is connected to the slurry inlet of the mixer of the adjacent washing and filtering unit.

3. The continuous washing and filtration system according to claim 2, wherein The number of the washing and filtering units is N, and N is an integer not less than 3.

4. The continuous washing and filtration system according to claim 3, characterized in that, The overflow port of the thickener of the nth washing and filtering unit is connected to the washing water inlet of the mixer of the (n - 1)th washing and filtering unit, where n is an integer and 1 < n ≤ N.

5. The continuous washing and filtering system according to any one of claims 1-4, characterized in that The slurry inlet of the mixer of the first washing and filtering unit is connected to a reaction kettle.

6. The continuous washing and filtration system according to claim 3 or 4, characterized in that, The continuous washing and filtering system further includes a transfer pump. The underflow port of the hydrocyclone of the last washing and filtering unit is connected to the transfer pump, and the discharge port of the thickener of the last washing and filtering unit is connected to the transfer pump.

7. The continuous washing and filtering system according to claim 2, wherein The washing and filtering unit further includes a turbidimeter. The turbidimeter is arranged between the overflow port of the hydrocyclone and the thickener, and the turbidimeter is electrically connected to the booster pump.

8. The continuous washing and filtering system according to claim 1, characterized in that, The mixer is a mixing pump.

9. The continuous washing and filtering system according to claim 1, characterized in that The washing and filtering unit includes a first washing and filtering unit, a second washing and filtering unit, a third washing and filtering unit, and a fourth washing and filtering unit; The first washing and filtering unit includes a first mixer, a first booster pump, and a first hydrocyclone. The first mixer has a first slurry inlet, a first washing water inlet, and a first mixed slurry outlet. The first mixed slurry outlet is connected to the first hydrocyclone through the first booster pump; The second washing and filtering unit includes a second mixer, a second booster pump, and a second hydrocyclone. The second mixer has a second slurry inlet, a second washing water inlet, and a second mixed slurry outlet. The second slurry inlet is connected to the underflow port of the first hydrocyclone, and the second mixed slurry outlet is connected to the second hydrocyclone through the second booster pump; The third washing and filtering unit includes a third mixer, a third booster pump, and a third hydrocyclone. The third mixer has a third slurry inlet, a third washing water inlet, and a third mixed slurry outlet. The third slurry inlet is connected to the underflow port of the second hydrocyclone, and the third mixed slurry outlet is connected to the third hydrocyclone through the third booster pump; The fourth washing and filtering unit includes a fourth mixer, a fourth booster pump, and a fourth hydrocyclone. The fourth mixer has a fourth slurry inlet, a fourth washing water inlet, and a fourth mixed slurry outlet. The fourth slurry inlet is connected to the underflow port of the third hydrocyclone, and the fourth mixed slurry outlet is connected to the fourth hydrocyclone through the fourth booster pump.

10. The continuous washing and filtration system according to claim 9, wherein, The first washing and filtering unit further includes a first thickener. The overflow port of the first hydrocyclone is connected to the first thickener, and the discharge port of the first thickener is connected to the second slurry inlet; The second washing and filtering unit further includes a second thickener. The overflow port of the second cyclone is connected to the second thickener. The discharge port of the second thickener is connected to the third slurry inlet. The overflow port of the second thickener is connected to the first washing water inlet; The third washing and filtering unit further includes a third thickener. The overflow port of the third cyclone is connected to the third thickener. The discharge port of the third thickener is connected to the fourth slurry inlet. The overflow port of the third thickener is connected to the second washing water inlet; The fourth washing and filtering unit further includes a fourth thickener. The overflow port of the fourth cyclone is connected to the fourth thickener. The overflow port of the fourth thickener is connected to the third washing water inlet.

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