A counterflow parallel wet-process phosphoric acid filtration high-efficiency washing device and washing method

Abstract

The application discloses a countercurrent parallel wet-process phosphoric acid filtering high-efficiency washing device and a washing method, which comprises a rotary table filter, a cleaning washing water tank, a filter cloth flushing water tank, a cloth lower water tank, a cleaning washing water pump, a five-washing pump, a four-washing pump, a three-washing pump, a two-washing pump, a one-washing pump, a return acid pump, a filtrate pump, a filter cloth flushing pump, a wet residue hopper, a filter cloth flushing regeneration nozzle, a cleaning three-washing water spraying pipe, a cleaning two-washing water spraying pipe, a cleaning one-washing water spraying pipe, a three-washing water distribution box, a two-washing water distribution box, a one-washing water distribution box and a slurry distribution box. The application combines the process characteristics of filtering phosphogypsum wet discharge, sets reasonable filtering and washing subareas and washing liquid collecting subareas, effectively improves the filtering and washing area, obviously improves the filtering gypsum washing efficiency under the same washing water adding condition, and improves the phosphorus yield of the wet-process phosphoric acid production.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wet-process phosphoric acid phosphogypsum filtration and washing, and particularly relates to a countercurrent parallel wet-process phosphoric acid filtration and efficient washing device and a washing method. BACKGROUND

[0002] In recent years, the wet-process phosphoric acid industry has developed rapidly, the technical level of devices has been continuously improved, and the scale of single device has been continuously increased. With the continuous improvement of the production level of the phosphoric acid industry, and the continuous improvement of the requirement for resource utilization, it is necessary to further improve the washing efficiency of the filtration process of the wet-process phosphoric acid, so as to further improve the utilization rate of phosphorus and reduce the consumption of phosphate rock. At present, most of the wet-process phosphoric acid production adopts the sulfuric acid method two-water production process, sulfuric acid is used to react with phosphate rock to generate phosphoric acid slurry, dilute phosphoric acid is obtained through a filter, and the filtered phosphogypsum is stored after washing. The storage of phosphogypsum adopts two technologies of dry discharge and dry storage and wet discharge and storage. In the past, the production device was small, and the dry discharge and dry storage technology was generally adopted. Due to the limitation of this slag discharge technology, the water content of the filtered gypsum cannot be too high, otherwise the transportation of the phosphogypsum will be affected, and finally the normal operation of the production will be affected, so a considerable area of the filter disc surface is required to perform the gypsum drying treatment after the slurry filtration and washing on the filter, so as to ensure that the water content of the phosphogypsum is within the controllable range. Now many enterprises adopt the wet discharge and storage technology of the phosphogypsum, but after adopting the wet discharge technology, the washing idea of the filtration and washing is still the same as that of the dry discharge, so a large amount of filtration area on the filter is still used for the drying of the gypsum, which reduces the effective washing area of the gypsum and is not conducive to the efficient washing of the gypsum and the improvement of the phosphorus recovery rate. SUMMARY

[0003] The present application provides a countercurrent parallel wet-process phosphoric acid filtration and efficient washing device and a washing method to solve the problems in the background art.

[0004] The scheme of the present application is as follows:

[0005] A countercurrent parallel wet-process phosphoric acid filtration and efficient washing device, comprising a rotary table filter, a clean washing water tank, a filter cloth flushing water tank, a cloth under water tank, a clean washing water pump, a five-washing pump, a four-washing pump, a three-washing pump, a two-washing pump, a one-washing pump, a return acid pump, a filtrate pump, a filter cloth flushing pump, a wet slag hopper, a filter cloth flushing regeneration nozzle, a clean three-washing water spraying pipe, a clean two-washing water spraying pipe, a clean one-washing water spraying pipe, a three-washing water distribution box, a two-washing water distribution box, a one-washing water distribution box, and a slurry distribution box.

[0006] The rotary table filter comprises a filter disc surface and a staggered air disc, the staggered air disc is composed of an upper staggered air disc and a lower staggered air disc, and the filter disc surface is sequentially divided into a disc surface primary filtration zone, a disc surface filtrate zone, a disc surface one-washing zone, a disc surface two-washing zone, a disc surface three-washing zone, a disc surface cleaning zone one, a disc surface cleaning zone two, a disc surface cleaning zone three, and a slag unloading and filter cloth flushing regeneration zone according to the working process of the rotary table filter.

[0007] The liquid filtered by the filter layers in each area on the filter disc surface enters the lower aeration disc collecting tank of the lower aeration disc, and the lower aeration disc collecting tank is also divided into collecting tank primary filtration area, collecting tank filtrate area, collecting tank first washing area, collecting tank second washing area, collecting tank mixing area, collecting tank cleaning area two, collecting tank cleaning area three, disc washing water collecting area one and disc washing water collecting area two corresponding to the filter disc surface, and the filtered and washed gypsum and the cloth flushing regenerated cloth water enter the wet residue hopper, the residue discharge and the filter cloth flushing regeneration area pass through the filter cloth to discharge water which enters the cloth under water tank and the slurry tank; the collecting mixing area collects the washing liquid discharged from the disc three washing area and the disc cleaning area one; the disc washing water collecting area one collects the first phosphorus-containing cloth under water in the residue discharge and the filter cloth flushing regeneration area, and the disc washing water collecting area two collects the subsequent cloth under water in the residue discharge and the filter cloth flushing regeneration area.

[0008] The filter cloth flushing water tank outlet is connected with the filter cloth flushing pump, the filter cloth flushing pump outlet pipe is connected with the filter cloth flushing regeneration nozzle, the clean washing water tank outlet pipe is connected with the clean washing water pump, the clean washing water pump outlet pipeline is connected with the upper clean three washing water spraying pipe of the filter disc surface, the collecting tank cleaning area three outlet pipeline is connected with the five washing pump, the five washing pump outlet pipe is connected with the upper clean two washing water spraying pipe of the filter disc surface, the collecting tank cleaning area two outlet pipeline is connected with the four washing pump, and the four washing pump outlet pipe is connected with the upper clean one washing water spraying pipe of the filter disc surface.

[0009] The filter cloth flushing water collecting area one outlet pipeline of the lower aeration disc collecting tank is connected with the cloth under water tank, the cloth under water tank outlet is connected with the three washing pump, the three washing pump outlet pipe is connected with the upper three washing water distribution box of the filter disc surface, the collecting tank mixing area outlet pipeline is connected with the two washing pump, the two washing pump outlet pipeline is connected with the upper two washing water distribution box of the filter disc surface, the collecting tank second washing area outlet pipeline is connected with the one washing pump, the one washing pump outlet pipeline is connected with the upper one washing water distribution box of the filter disc surface, the collecting tank first washing area outlet pipeline is connected with the return acid pump, and the dilute phosphoric acid sent out by the return acid pump is sent to the reaction tank as return acid.

[0010] The reaction generated phosphoric acid slurry is sent to the slurry distribution box on the filter disc surface, and the filtrate passing through the filter cloth enters the collecting tank primary filtration area and the collecting tank filtrate area, and the collecting tank primary filtration area outlet pipeline is connected to the collecting tank first washing area outlet pipeline.

[0011] The collecting tank filtrate area outlet pipeline is connected with the filtrate pump, and the filtrate is sent into the dilute acid tank by the filtrate pump for use as a product.

[0012] As a preferred technical scheme, the clean washing water tank is provided with a steam heating pipe; the cloth under water tank is provided with a steam heating pipe and a stirring paddle; and the filter cloth flushing water tank is provided with a steam heating pipe and a stirring paddle.

[0013] As a preferred technical scheme, the washing area on the filter disc surface is composed of two washing areas of clean water washing and cloth under water washing.

[0014] As a preferred technical scheme, the washing mode of the disc surface cleaning area one, the disc surface cleaning area two and the disc surface cleaning area three is a clean water three times countercurrent washing mode, that is, the heated clean process water is the three washing liquid, the washing liquid after use of the three washing liquid is the two washing liquid, and the washing liquid after use of the two washing liquid is the one washing liquid.

[0015] As a preferred technical scheme, the washing liquid of the clean water and the three washing liquid of the cloth under water are mixed together in the collection box mixing area.

[0016] As a preferred technical scheme, the washing mode of the disc surface one washing area, the disc surface two washing area and the disc surface three washing area is a countercurrent washing mode, wherein the filter disc cloth under water is used as the three washing water, the washing liquid in the collection box mixing area is used as the two washing water, and the washing liquid after use of the two washing water is used as the one washing water.

[0017] As a preferred technical scheme, the disc washing water collection area is divided into a first area and a second area, the first area collects the washing liquid containing part of the acid remaining in the filter disc after washing, and is used as washing water, and the second area collects the disc washing water not containing the washing liquid and enters into the gypsum slurry.

[0018] As a preferred technical scheme, the washing water distribution of the disc surface one washing area, the disc surface two washing area and the disc surface three washing area adopts a distribution box, and the washing water distribution of the disc surface cleaning area one, the disc surface cleaning area two and the disc surface cleaning area three adopts a spray pipe.

[0019] As a preferred technical scheme, each area separation block in the lower air distribution disc adopts an adjustable structure, and the area size is adjusted according to the production situation.

[0020] The application further discloses a washing method of the countercurrent parallel wet-process phosphoric acid filter high-efficiency washing device.

[0021] S1, starting the rotary table filter and the filter discharging screw;

[0022] S2, starting the filter vacuum pump;

[0023] S2, adding clean water into the clean washing water tank, and heating the water by steam through a steam adding pipe;

[0024] S3, adding water to the filter cloth flushing water tank, starting the stirring slurry, and flushing the water by steam;

[0025] S4, starting the filter cloth flushing pump;

[0026] S5, sending the reaction slurry into the slurry distribution box;

[0027] S6, start the filtrate pump, the acid return pump;

[0028] S7, after the disc washing water enters the cloth water tank through the filter cloth, start the cloth water tank stirring slurry, and steam is introduced for heating;

[0029] S8, after the filtration machine system vacuum degree is established, start the three washing pump;

[0030] S9, start the two washing pump and the one washing pump in turn;

[0031] S10, start the clean washing water pump;

[0032] S11, start the five washing pump and the four washing pump in turn.

[0033] Working principle:

[0034] The present application has a positive relationship between the washing rate of the filtered gypsum and the washing water consumption, the more washing water is added, the better the washing effect is. The maximum washing water that can be added in the wet-process phosphoric acid filtration must meet the control requirements of the slurry liquid-solid ratio of the phosphoric acid reaction system and the dilute phosphoric acid concentration index, so the addition amount of washing water is limited. In order to improve the washing efficiency of the filtered gypsum, the conventional phosphogypsum washing method in production adopts three times of countercurrent washing, and the washing water is used multiple times in series to increase the washing water amount and improve the washing efficiency. The commonly used washing water is the cloth water under the filter cloth, and a small amount of phosphorus is contained in the water due to the mixing of the washing liquid that has not been completely discharged in the filter disc, which affects the further improvement of the gypsum washing rate. The current wet stacking washing method still uses the washing thinking of the original dry stacking, and about 20% of the area is used as a drying area after three washings, so that the effective washing area is significantly reduced, and the phosphogypsum washing rate is affected.

[0035] The present application makes full use of the characteristics of wet stacking, and the moisture of the washed gypsum does not need to be dried as much as possible. The area used for drying before is used as a washing area, and the washing water that can be added to the system is divided into two parts. About 25% of the washing water is clean water without phosphorus, which is used as clean washing water. The clean water washing adopts three times of countercurrent washing, forming the first three times of countercurrent washing. The cloth water under the filter cloth with a small amount of phosphorus is introduced into the cloth water tank, and the water amount is about 75% of the total washing water, which is used as the three washing water of the second three times of countercurrent washing. The three washing liquid of the second level is combined with the one washing liquid of the first level to form the two washing water of the second level, and the two washing liquid is used as one washing water, thereby forming two three times of countercurrent washing. Compared with the original technology, the three times of countercurrent washing of the clean part of the water is increased, and the washing water amount is increased by 25% under the same washing water supplement condition, thereby effectively improving the washing efficiency of the filtered gypsum, and the water-soluble phosphorus in the gypsum is significantly reduced, and the recovery rate of phosphorus is improved.

[0036] While improving the above, one area of the original slag and filter cloth flushing water is changed into two sub-areas, the first area receives the cloth water mixed with the remaining part of the washing liquid in the filter disc after the end of washing, enters the cloth water tank, and is used as the three washing water of the second three reverse washing. The second area is located behind the first area and only receives part of the cloth water. The part of the water does not contain residual washing liquid and does not increase phosphorus. The phosphorus in the phosphogypsum slurry will not increase the loss of phosphorus, so that the original phosphorus-containing cloth water is more than the amount of filter washing water under normal circumstances, which causes part of the cloth water to enter the phosphogypsum slurry, resulting in the loss of phosphorus.

[0037] Due to the adoption of the above technical scheme, the high-efficiency washing device and method for wet-process phosphoric acid filtration by reverse flow parallel connection, including a rotary table filter, a clean washing water tank, a filter cloth flushing water tank, a cloth water tank, a clean washing water pump, a five-washing pump, a four-washing pump, a three-washing pump, a two-washing pump, a one-washing pump, a return acid pump, a filtrate pump, a filter cloth flushing pump, a wet slag hopper, a filter cloth flushing regeneration nozzle, a clean three-washing water spraying pipe, a clean two-washing water spraying pipe, a clean one-washing water spraying pipe, a three-washing water distribution box, a two-washing water distribution box, a one-washing water distribution box, and a slurry distribution box.

[0038] Advantages of the present application:

[0039] The present application improves the effective area of the filter washing area, and relatively increases the washing water amount of the phosphogypsum by adopting a two-stage three-time reverse flow parallel washing mode under the same washing water addition condition, thereby effectively reducing the water-soluble phosphorus content in the gypsum after washing and improving the utilization rate of phosphorus.

[0040] The present application combines the process characteristics of wet discharge of filtered phosphogypsum, sets reasonable filter washing sub-areas and washing liquid collection sub-areas, effectively improves the filter washing area, and can significantly improve the filter gypsum washing efficiency and improve the phosphorus yield of wet-process phosphoric acid production under the same washing water addition condition. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 The figure is a flowchart of the invention;

[0042] Figure 2 The figure is a schematic diagram of the filter disc surface sub-area of the invention;

[0043] Figure 3 The figure is a schematic diagram of the lower staggered gas disc collection box sub-area of the invention;

[0044] In the figure, 1-filter machine; 110-filter machine disc surface; 111-disc surface primary filtration area; 112-disc surface filtrate area; 113-disc surface first washing area; 114-disc surface second washing area; 115-disc surface third washing area; 116-disc surface cleaning first area; 117-disc surface cleaning second area; 118-disc surface cleaning third area; 119-removal of residue and filter cloth flushing regeneration area; 120-lower air distribution disc collection box; 121-collection box primary filtration area; 122-collection box filtrate area; 123-collection box first washing area; 124-collection box second washing area; 125-collection box mixing area; 126-collection box cleaning second area; 127-collection box cleaning third area; 128-flushing water collection first area; 129-flushing water collection second area;

[0045] 2-clean washing water tank; 3-filter cloth flushing water tank; 4-cloth flushing water tank; 5-clean washing water pump; 6-fifth washing pump; 7-fourth washing pump; 8-third washing pump; 9-second washing pump; 10-first washing pump; 11-return acid pump; 12-filtrate pump; 13-filter cloth flushing pump; 14-wet residue hopper; 15-filter cloth flushing regeneration nozzle; 16-clean third washing water spraying pipe; 17-clean second washing water spraying pipe; 18-clean first washing water spraying pipe; 19-third washing water distribution box; 20-second washing water distribution box; 21-first washing water distribution box; 22-slurry distribution box. DETAILED DESCRIPTION

[0046] The application provides a high-efficiency washing device and method for countercurrent parallel wet-process phosphoric acid filtration.

[0047] In order to make the technical means, creative features, purposes and effects achieved by the application easy to understand, the application is further described below in combination with specific examples.

[0048] EMBODIMENT

[0049] As shown in Figure 1 , Figure 2 and Figure 3 , a high-efficiency washing device for countercurrent parallel wet-process phosphoric acid filtration includes a rotary table filter (1), a clean washing water tank (2), a filter cloth flushing water tank (3), a cloth flushing water tank (4), a clean washing water pump (5), a fifth washing pump (6), a fourth washing pump (7), a third washing pump (8), a second washing pump (9), a first washing pump (10), a return acid pump (11), a filtrate pump (12), a filter cloth flushing pump (13), a wet residue hopper (14), a filter cloth flushing regeneration nozzle (15), a clean third washing water spraying pipe (16), a clean second washing water spraying pipe (17), a clean first washing water spraying pipe (18), a third washing water distribution box (19), a second washing water distribution box (20), a first washing water distribution box (21), and a slurry distribution box (22).

[0050] The rotary filter (1) comprises a filter disc surface (110) and a staggered air disc, the staggered air disc is composed of an upper staggered air disc and a lower staggered air disc, and the filter disc surface (110) is sequentially divided into a disc surface primary filtration area (111), a disc surface filtrate area (112), a disc surface first washing area (113), a disc surface second washing area (114), a disc surface third washing area (115), a disc surface cleaning first area (116), a disc surface cleaning second area (117), a disc surface cleaning third area (118), and a residue discharging and filter cloth flushing regeneration area (119) according to the working process of the rotary filter.

[0051] The liquid on the filter disc surface (110) after passing through the filter layers of each area enters the lower staggered air disc collection tank (120) of the staggered air disc, and the lower staggered air disc collection tank (120) is also divided into a collection tank primary filtration area (121), a collection tank filtrate area (122), a collection tank first washing area (123), a collection tank second washing area (124), a collection tank mixing area (125), a collection tank cleaning second area (126), a collection tank cleaning third area (127), a disc flushing water collection first area (128), and a disc flushing water collection second area (129) corresponding to the filter disc surface (110), the filtered and washed gypsum and the filter cloth flushing regenerated cloth water enter the wet residue hopper (14), and the residue discharging and filter cloth flushing regeneration area (119) passes through the cloth under water to enter the cloth under water tank (4) and the slurry tank; the collection mixing area (125) collects the washing liquid discharged from the disc surface third washing area (115) and the disc surface cleaning first area (116); the disc flushing water collection first area (128) collects the initial cloth under water of the residue discharging and filter cloth flushing regeneration area (119), and the disc flushing water collection second area (129) collects the subsequent cloth under water of the residue discharging and filter cloth flushing regeneration area (119);

[0052] The filter cloth flushing water tank (3) outlet is connected with the filter cloth flushing pump (13), the filter cloth flushing pump (13) outlet pipe is connected with the filter cloth flushing regeneration nozzle (15), the clean washing water tank (2) outlet pipe is connected with the clean washing water pump (5), the clean washing water pump (5) outlet pipeline is connected with the upper clean three washing water spraying pipe (16) of the filter disc surface (110), the collection tank cleaning third area (127) outlet pipeline is connected with the five washing pump (6), the five washing pump (6) outlet pipe is connected with the upper clean two washing water spraying pipe (17) of the filter disc surface (110), the collection tank cleaning second area (126) outlet pipeline is connected with the four washing pump (7), and the four washing pump (7) outlet pipe is connected with the upper clean one washing water spraying pipe (18) of the filter disc surface (110);

[0053] The pipe of the outlet of the washing water collecting area (128) of the lower gas pocket collecting tank (120) is connected with the cloth under water tank (4), the outlet of the cloth under water tank (4) is connected with the three washing pump (8), the outlet pipe of the three washing pump (8) is connected with the three washing water distribution tank (19) on the filter machine disc surface (110), the outlet pipe of the collecting tank mixing area (125) is connected with the two washing pump (9), the outlet pipe of the two washing pump (9) is connected with the two washing water distribution tank (20) on the filter machine disc surface (110), the outlet pipe of the collecting tank two washing area (124) is connected with the one washing pump (10), the outlet pipe of the one washing pump (10) is connected with the one washing water distribution tank (21) on the filter machine disc surface (110), the outlet pipe of the collecting tank one washing area (123) is connected with the acid return pump (11), the dilute phosphoric acid sent by the acid return pump (11) is sent to the reaction tank as the acid return;

[0054] The phosphoric acid slurry generated by the reaction is sent to the slurry distribution tank (22) on the filter machine disc surface (110), the filtrate passing through the filter cloth is respectively introduced into the collecting tank primary filtration area (121) and the collecting tank filtrate area (122), the outlet pipe of the collecting tank primary filtration area (121) is connected to the pipe of the outlet of the collecting tank one washing area (123);

[0055] The outlet pipe of the collecting tank filtrate area (122) is connected with the filtrate pump (12), and the filtrate is sent into the dilute acid tank through the filtrate pump (12) for use as the product.

[0056] The clean washing water tank (2) is provided with a steam heating pipe; the cloth under water tank (4) is provided with a steam heating pipe and a stirring paddle; and the filter cloth washing water tank (3) is provided with a steam heating pipe and a stirring paddle.

[0057] The washing area on the filter machine disc surface (110) is composed of two washing areas, namely the clean water washing area and the cloth under water washing area.

[0058] The washing mode of the disc cleaning area one (116), the disc cleaning area two (117) and the disc cleaning area three (118) is the clean water three times countercurrent washing mode, that is, the heated clean process water is used as the three washing liquid, the used three washing liquid is used as the two washing liquid, and the used two washing liquid is used as the one washing liquid.

[0059] The clean water washing liquid and the cloth under water three washing liquid are mixed together in the collecting tank mixing area (125).

[0060] The washing mode of the disc one washing area (113), the disc two washing area (114) and the disc three washing area (115) is the countercurrent washing mode, wherein the filter cloth under water is used as the three washing water, the washing liquid in the collecting tank mixing area (125) is used as the two washing water, and the used two washing water is used as the one washing water.

[0061] The plate washing water collection area is divided into a first area and a second area, the first area collects part of the acid washing liquid still contained in the filter plate after washing and is used as washing water, and the second area collects the plate washing water without washing liquid and enters into the gypsum slurry.

[0062] The washing water distribution of the first plate washing area (113), the second plate washing area (114) and the third plate washing area (115) adopts a distribution box, and the washing water distribution of the first plate cleaning area (116), the second plate cleaning area (117) and the third plate cleaning area (118) adopts a spray pipe.

[0063] The area separation blocks in the lower air distribution plate adopt an adjustable structure, and the area size is adjusted according to the production situation.

[0064] The operation method of the above filter device during washing is as follows:

[0065] S1. Start the rotary table filter 1 and the filter discharge screw;

[0066] S2. Start the filter vacuum pump; clean water 30m 3 is added into the clean washing water tank 2, steam is added through a steam adding pipe to heat the water to 65-75℃;

[0067] S3. Add water to the filter cloth flushing water tank 3, start the stirring paddle, add steam to heat the flushing water, and control the water temperature to be 65-75℃;

[0068] S4. Start the filter cloth flushing pump 13;

[0069] S5. Send the reaction slurry 300m 3 to the slurry distribution box 22;

[0070] S6. Start the filtrate pump 12 and the acid return pump 11;

[0071] S7. After the plate washing water enters the cloth under water tank 4 through the filter cloth, start the cloth under water tank stirring paddle, add steam to heat, and control the water temperature to be 65-75℃;

[0072] S8. When the system vacuum degree of the filter 1 reaches 40kPa, start the three washing pump 8, and the three washing water quantity is 75m 3 ;

[0073] S9. Start the two washing pump 9 and the one washing pump 10 in sequence;

[0074] S10. Start the clean washing water pump 5, and the clean water flow is 30m 3 ;

[0075] S11. Start the five washing pump 6 and the four washing pump 7 in sequence.

[0076] The water-soluble phosphorus content of the filtered and washed gypsum can be controlled below 0.15%, which is 0.1% lower than that of the original filtering device, and the gypsum washing rate is increased by more than 0.5%. For a 300,000-ton-per-year phosphoric acid device, 1,500 tons of phosphoric acid can be produced per year.

[0077] The basic principles, main features and advantages of the present application are shown and described above. Those skilled in the art should understand that the present application is not limited by the above examples, and the above examples and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A high-efficiency washing device for countercurrent parallel wet phosphoric acid filtration, characterized in that: Includes a rotary table filter (1), a cleaning water tank (2), a filter cloth rinsing water tank (3), a filter cloth under water tank (4), a cleaning water pump (5), a fifth-wash pump (6), a fourth-wash pump (7), a third-wash pump (8), a second-wash pump (9), a first-wash pump (10), a back acid pump (11), a filtrate pump (12), a filter cloth rinsing pump (13), a wet slag hopper (14), a filter cloth rinsing and regeneration nozzle (15), a third-wash water spray pipe (16), a second-wash water spray pipe (17), a first-wash water spray pipe (18), a third-wash water distribution box (19), a second-wash water distribution box (20), a first-wash water distribution box (21), and a slurry distribution box (22); The rotary table filter (1) includes a filter plate (110) and a cross-flow plate. The cross-flow plate is composed of an upper cross-flow plate and a lower cross-flow plate. According to the working process of the rotary table filter, the filter plate (110) is divided into the plate primary filtration area (111), the plate filtrate area (112), the plate first washing area (113), the plate second washing area (114), the plate third washing area (115), the plate cleaning area 1 (116), the plate cleaning area 2 (117), the plate cleaning area 3 (118), and the slag unloading and filter cloth rinsing and regeneration area (119). The liquid that has passed through the filtration layers in each area on the filter plate (110) enters the lower air-dissipation plate collection box (120) of the air-dissipation plate. The lower air-dissipation plate collection box (120) is also divided into a collection box primary filtration area (121), a collection box filtrate area (122), a collection box first washing area (123), a collection box second washing area (124), a collection box mixing area (125), a collection box second cleaning area (126), a collection box third cleaning area (127), a flushing water collection area (128), and a flushing water collection area (129) corresponding to the filter plate (110). The gypsum after filtration and the water from the filter cloth rinsing and regeneration enter the wet slag hopper (14). The water from the filter cloth passing through the slag unloading and filter cloth rinsing and regeneration zone (119) enters the under-cloth water tank (4) and the slurry tank respectively. The collection box mixing zone (125) collects the washing liquid discharged from the three-wash zone (115) and the first cleaning zone (116) of the plate surface. The first flushing water collection zone (128) collects the initial phosphorus-containing under-cloth water from the slag unloading and filter cloth rinsing and regeneration zone (119). The second flushing water collection zone (129) collects the subsequent under-cloth water from the slag unloading and filter cloth rinsing and regeneration zone (119). The outlet of the filter cloth rinsing water tank (3) is connected to the filter cloth rinsing pump (13), the outlet pipe of the filter cloth rinsing pump (13) is connected to the filter cloth rinsing and regeneration nozzle (15), the outlet pipe of the cleaning water tank (2) is connected to the cleaning water pump (5), the outlet pipe of the cleaning water pump (5) is connected to the cleaning third washing water spray pipe (16) on the filter plate (110), the outlet pipe of the cleaning zone 3 of the collection box (127) is connected to the fifth washing pump (6), the outlet pipe of the fifth washing pump (6) is connected to the cleaning second washing water spray pipe (17) on the filter plate (110), the outlet pipe of the cleaning zone 2 of the collection box (126) is connected to the fourth washing pump (7), and the outlet pipe of the fourth washing pump (7) is connected to the cleaning first washing water spray pipe (18) on the filter plate (110). The outlet of the flushing water collection zone (128) of the lower gas plate collection box (120) is connected to the water tank (4) by a pipe. The outlet of the water tank (4) is connected to the third washing pump (8). The outlet pipe of the third washing pump (8) is connected to the third washing water distribution box (19) on the filter plate (110). The outlet of the mixing zone (125) of the collection box is connected to the second washing pump (9) by a pipe. The outlet of the second washing pump (9) is connected to the second washing water distribution box (20) on the filter plate (110) by a pipe. The outlet of the second washing zone (124) of the collection box is connected to the first washing pump (10) by a pipe. The outlet of the first washing pump (10) is connected to the first washing water distribution box (21) on the filter plate (110) by a pipe. The outlet of the first washing zone (123) of the collection box is connected to the acid return pump (11) by a pipe. The dilute phosphoric acid sent by the acid return pump (11) is sent to the reaction tank as acid return. The phosphoric acid slurry generated by the reaction is sent to the slurry distribution box (22) on the filter plate (110). The filtrate that passes through the filter cloth enters the primary filtration zone (121) and the filtrate zone (122) of the collection box respectively. The outlet of the primary filtration zone (121) of the collection box is connected to the outlet of the first washing zone (123) of the collection box by a pipe. The outlet of the filtrate collection tank (122) is connected to the filtrate pump (12) via a pipe, and the filtrate is pumped into the dilute acid tank for use as a product. The washing method of the first cleaning zone (116), the second cleaning zone (117), and the third cleaning zone (118) is a three-stage countercurrent washing method with clean water. That is, the clean process water after heating is the third washing liquid, the washing liquid after the third washing liquid is used is the second washing liquid, and the washing liquid after the second washing liquid is used is the first washing liquid. The washing method of the first cleaning zone (113), the second cleaning zone (114), and the third cleaning zone (115) is a countercurrent washing method. The water under the filter flushing cloth is the third washing water, the washing liquid in the mixing zone (125) of the collection box is the second washing water, and the washing liquid after the second washing water is used is the first washing water.

2. The high-efficiency washing device for countercurrent parallel wet phosphoric acid filtration as described in claim 1, characterized in that: The cleaning water tank (2) is equipped with a steam heating pipe; the cloth under water tank (4) is equipped with a steam heating pipe and a stirring paddle; the filter cloth rinsing water tank (3) is equipped with a steam heating pipe and a stirring paddle.

3. The high-efficiency washing device for countercurrent parallel wet phosphoric acid filtration as described in claim 1, characterized in that: The washing area on the filter disc (110) consists of two washing areas: a clean water washing area and a cloth-covered water washing area.

4. The high-efficiency washing device for countercurrent parallel wet phosphoric acid filtration as described in claim 1, characterized in that: The washing liquid of the clean water and the three-wash liquid of the cloth are mixed together in the mixing zone (125) of the collection box.

5. The high-efficiency washing device for countercurrent parallel wet phosphoric acid filtration as described in claim 1, characterized in that: The rinsing water collection area is divided into a first zone and a second zone. The first zone collects the acidic washing liquid that is still present in the filter plate after washing, which is used as washing water. The second zone collects the rinsing water without washing liquid, which enters the gypsum slurry.

6. The high-efficiency washing device for countercurrent parallel wet phosphoric acid filtration as described in claim 1, characterized in that: The washing water distribution in the first washing zone (113), the second washing zone (114), and the third washing zone (115) is provided by a distribution box, while the washing water distribution in the first washing zone (116), the second washing zone (117), and the third washing zone (118) is provided by a spray pipe.

7. The high-efficiency washing device for countercurrent parallel wet phosphoric acid filtration as described in claim 1, characterized in that: The partition blocks of each area in the lower air plate adopt an adjustable structure, and the size of the area can be adjusted accordingly according to the production situation.

8. A washing method for a high-efficiency washing device for countercurrent parallel wet phosphoric acid filtration as described in any one of claims 1 to 7, characterized in that, Includes the following steps: S1. Start the rotary table filter and the filter discharge screw; S2. Start the filter vacuum pump; S3. Add clean water to the clean water tank and heat the water by introducing steam through the steam inlet pipe. S4. Add water to the filter cloth rinsing tank, start the agitator, and heat the rinsing water with steam. S5. Start the filter cloth rinsing pump; S6. The reaction slurry is fed into the slurry distribution box; S7. Start the filtrate pump and acid return pump; S8. After the flushing water enters the under-cloth water tank through the filter cloth, start the under-cloth water tank agitator and introduce steam for heating. S9. After the vacuum level of the filter system is established, start the three-wash pump; S10. Start the second washing pump and the first washing pump in sequence; S11. Start the cleaning water pump; S12. Start the fifth and fourth washing pumps in sequence.

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