Production facilities for high-quality sodium fluorosilicate

Abstract

This utility model discloses a production apparatus for high-quality sodium fluorosilicate, belonging to the field of fluorochemical technology. It includes a material tank, a salt dissolving tank, a reaction tank, a crystal growth tank, a material tank II, a thickener, a centrifuge, a centrifugal liquid storage tank, a washing tank, a settling tank, and a mother liquor tank. Material tank I and the salt dissolving tank are connected to the reaction tank via pipelines. The centrifugal liquid storage tank is connected to the centrifugal liquid outlet of the centrifuge via a pipeline. The reaction tank, crystal growth tank, material tank II, washing tank, thickener, and centrifuge are sequentially connected via pipelines. The overflow port of the washing tank is connected to the inlet of the settling tank via a pipeline. The underflow outlet at the bottom of the settling tank is connected to material tank II via a pipeline, and the clear liquid outlet at its upper part is connected to the mother liquor tank via a pipeline. The centrifugal liquid storage tank is connected to the settling tank via a pipeline, and the clear water inlet of the washing tank is connected to a clear water supply structure via a pipeline.

Description

Technical Field

[0001] This utility model belongs to the field of fluorochemical technology, and specifically relates to a production device for high-quality sodium fluorosilicate, which can improve purity and crystal size. Background Technology

[0002] The production of phosphoric acid from phosphate rock generates a large amount of fluorine-containing gas. Currently, this gas is absorbed by water to produce fluorosilicic acid (concentration 5-20%), which is then processed into other products, thus recovering the fluorine resources from the phosphate rock. In existing technology, fluorosilicic acid can be reacted with sodium sulfate to obtain sodium fluorosilicate. The production process of sodium fluorosilicate can be found in the following patent description:

[0003] For example, patent application number CN201210287774.8 discloses a production process for sodium fluorosilicate, which mainly includes the following steps:

[0004] (1) Prepare a sodium sulfate solution with a mass fraction of 26%-32%.

[0005] (2) Add 8%-14% fluorosilicic acid by mass while stirring; The 8%-14% fluorosilicic acid from the fluorosilicic acid settling tank is heated to 35-40℃ by heat exchanger and steam exchange and placed in the fluorosilicic acid storage tank for later use; The prepared sodium sulfate solution is sent from the salting tank to the sodium fluorosilicate synthesis tank by metering pump. When the liquid level of the sodium sulfate solution in the synthesis tank reaches half, the stirrer is started and the speed of the stirrer is maintained at 30-40 r / min. Add the above-mentioned 8%-14% fluorosilicic acid by mass while stirring.

[0006] (3) Control the amount of sodium sulfate solution and adjust the amount of fluorosilicic acid so that the amount of fluorosilicic acid is 3%-6% more than the theoretical amount calculated according to the chemical equation. Under stirring, use a metering pump to send the metered fluorosilicic acid to the synthesis tank and sodium sulfate solution for synthesis reaction. The amount of fluorosilicic acid is added at 3%-6% more than the theoretical mass of the chemical reaction.

[0007] (4) After the reaction of sodium sulfate and fluorosilicic acid is completed, crystal growth is carried out; after the sodium sulfate solution and fluorosilicic acid solution react in the synthesis tank for 20-30 minutes, the sodium fluorosilicate crystal slurry generated by the reaction is put into the first crystal growth tank from the bottom of the synthesis tank for crystal growth; the unreacted sodium sulfate and fluorosilicic acid solution overflows from the top overflow port of the synthesis tank into the first crystal growth tank to continue the reaction; the stirring speed of the agitator in the first crystal growth tank is controlled at 3-6 r / min, and the crystal slurry grown in the first crystal growth tank for 20-40 minutes is put into the second crystal growth tank from the bottom of the first crystal growth tank to continue crystal growth, and the wastewater after the reaction is completed enters the wastewater tank from the top overflow port of the crystal growth tank; the crystal slurry entering the second crystal growth tank continues to grow crystals for 20-40 minutes at a stirring speed of 3-6 r / min, and the crystals after crystal growth are completed are put into the washing tank from the bottom of the second crystal growth tank, and the excess wastewater overflows from the top of the crystal growth tank into the wastewater tank.

[0008] (5) Wash and separate sodium fluorosilicate crystals, and centrifuge and dry them; wash the crystals after crystal growth with an appropriate amount of industrial water until the pH reaches 3-4 to remove excess free acid and ensure crystal quality; after washing, the crystals and washing water are put into a centrifuge for centrifugation; the wastewater after centrifugation is put into a wastewater collection tank, and the product is put into a dryer for drying.

[0009] (6) Recovery of sulfuric acid and fluorosilicic acid: Wastewater from the first crystal growth tank, the second crystal growth tank and the centrifuge is collected and sent to the wastewater tank. The collected wastewater is pumped to the phosphoric acid extraction unit for phosphoric acid production, that is, to recover sulfuric acid and excess fluorosilicic acid.

[0010] For example, patent application number CN201710579788.X discloses a method for purifying defluorination residue to prepare sodium fluorosilicate, including the following steps:

[0011] a. Add fluorosilicic acid to the defluorination residue and heat to carry out the reaction; the reaction temperature is 70-90℃ and the reaction time is 30-60min.

[0012] b. Perform thickening separation on the slurry obtained in step a to obtain thickened supernatant and thick slurry.

[0013] c. Filter the slurry obtained in step b to obtain filtrate and filter cake. The filter cake is washed, dried and sieved to obtain sodium fluorosilicate.

[0014] For example, patent application number CN201710007544.4 discloses a method for producing sodium fluorosilicate using a dual-tank process, in which fluorosilicic acid is added in two stages and reacted in two separate tanks.

[0015] The reaction proceeds in an excess of sodium sulfate in the slurry in reaction tank #1, while maintaining an excess of fluorosilicic acid in the slurry in reaction tank #2.

[0016] Excessive; including the following steps:

[0017] (1) In reaction tank #1, a 30% sodium sulfate solution is added to a quantitative fluorosilicic acid solution under stirring. The sodium ion content in the solution is adjusted to be 15-20% excess. The reaction temperature is maintained at 40-50℃. After the reaction is carried out for 38-42 minutes, the reaction slurry is transported to reaction tank #2.

[0018] (2) Add fluorosilicic acid solution to reaction tank #2, maintain fluorosilicic acid in excess of 3-10%, maintain reaction temperature at 40-50℃, and after reaction for 38-42 minutes, transfer the reaction slurry to thickener #1.

[0019] (3) The first sedimentation and thickening is carried out in the No. 1 thickener, with a residence time of 2-4 minutes. The upper layer of suspension turbid liquid, namely sodium fluorosilicate mother liquor containing some silica gel ①, is separated and sent to the No. 1 mother liquor neutralization tank. The lower layer of thickened slurry in the tank is sent to the No. 2 thickener for the second sedimentation and thickening.

[0020] (4) After adding water to the No. 2 thickener and stirring evenly, the second sedimentation thickening is carried out. The residence time is 1-3 minutes. The upper layer of suspended turbid liquid, i.e. sodium fluorosilicate mother liquor ② containing some silica gel, is separated and sent to the No. 1 mother liquor neutralization tank. The lower layer of thick slurry is sent to the filter machine for filtration and washing with water.

[0021] (5) The filtered residue is dried in a dryer to obtain sodium fluorosilicate. The wash water containing trace amounts of sodium fluorosilicate solution ③ is then introduced into the No. 1 mother liquor neutralization tank.

[0022] (6) Mother liquor treatment: The mother liquors ① and ② obtained from the two thickening processes and the solution ③ obtained from filtration and washing are put into the No. 1 mother liquor neutralization tank for pre-neutralization reaction with calcium carbonate powder. The reaction temperature is 40-50℃ and the total reaction time is 1.5-2.0h. The pH is controlled to 2.5-3.0 and the reaction continues for 28-32min. Then, the solution is put into the No. 2 mother liquor neutralization tank, lime milk is added, the pH is adjusted to 6.5-7.0 and the reaction continues for 28-32min. After filtration, the filtrate is put into the wet phosphoric acid tailing system.

[0023] The existing sodium fluorosilicate production equipment includes a material tank 1, a salt dissolving tank, a reaction tank, a crystal growth tank, a material tank 2, a thickener, a centrifuge, and a centrifugal liquid storage tank. The material tank 1 and the salt dissolving tank are connected to the reaction tank through pipelines. The reaction tank, the crystal growth tank, the material tank 2, the thickener, and the centrifuge are connected in sequence through pipelines. The solid output from the centrifuge is dried and cooled to obtain sodium fluorosilicate product. The centrifugal liquid storage tank is connected to the centrifugal liquid outlet of the centrifuge through pipelines.

[0024] Since fluorosilicic acid is a byproduct of wet-process phosphoric acid production, it contains many other impurities. The reaction solution output from the reaction tank contains impurities such as sodium sulfate and silica gel, resulting in smaller crystals in the product. Summary of the Invention

[0025] To address the aforementioned problems, this utility model provides a production apparatus for high-quality sodium fluorosilicate, producing sodium fluorosilicate with high purity and large crystal particles. The technical solution is as follows:

[0026] This utility model provides a high-quality sodium fluorosilicate production apparatus. The apparatus includes a first material tank, a salt dissolving tank 4, a reaction tank 6, a crystal growth tank 7, a second material tank, a thickener 11, a centrifuge, and a centrifugal liquid storage tank. The first material tank and the salt dissolving tank 4 are both connected to the reaction tank 6 via pipelines. The centrifugal liquid storage tank is connected to the centrifugal liquid outlet of the centrifuge via a pipeline. The apparatus also includes a cleaning tank 10, a settling tank 12, and a mother liquor tank 13. The reaction tank 6, crystal growth tank 7, second material tank, cleaning tank 10, thickener 11, and centrifuge are connected sequentially via pipelines. The overflow port of the cleaning tank 10 is connected to the inlet of the settling tank 12 via a pipeline. The bottom outlet of the settling tank 12 is connected to the second material tank via a pipeline, and the clear liquid outlet at its upper part is connected to the mother liquor tank 13 via a pipeline. The centrifugal liquid storage tank is connected to the settling tank 12 via a pipeline, and the clear water inlet of the cleaning tank 10 is connected to a clear water supply structure via a pipeline.

[0027] Furthermore, the device also includes a solid-liquid separation structure 1 and a heat exchanger 2. The tail gas treatment device for wet-process phosphoric acid, the solid-liquid separation structure 1, the heat exchanger 2 and the material tank are connected in sequence through pipelines. The heat exchanger 2 and the cooling tower form a circulating cooling structure. The cooling tower serves as a clean water supply structure to provide clean water to the cleaning tank 10.

[0028] Specifically, in this embodiment of the present invention, the solid-liquid separation structure 1 is a plate and frame filter press, the heat exchanger 2 is a graphite cooler, and the cooling tower is a cooling tower of an ammonium phosphate production unit.

[0029] Further, in this embodiment of the present invention, the first material tank includes a fluorosilicic acid storage tank 3 and an elevated tank 5. The heat exchanger 2, the fluorosilicic acid storage tank 3, the elevated tank 5, and the reaction tank 6 are connected in sequence via pipelines. The fluorosilicic acid storage tank 3 is lower than the heat exchanger 2 and the elevated tank 5, and it is connected to the elevated tank 5 via a pipeline with a pump 14. The second material tank includes a ground tank 8 and an elevated tank 9. The crystal growth tank 7, the ground tank 8, the elevated tank 9, and the cleaning tank 10 are connected in sequence via pipelines. The overflow port at the top of the elevated tank 9 is connected to... The feed inlet of the settling tank 12 is connected to the bottom outlet of the settling tank 12 via a pipeline. The heights of the high-level tank 5, reaction tank 6, crystal growth tank 7 and bottom tank 8 decrease sequentially. The bottom tank 8 and mother liquor tank 13 are both lower than the settling tank 12. The high-level tank 9 is higher than the bottom tank 8. The bottom tank 8 is connected to the high-level tank 9 via a pipeline with pump 15. The heights of the high-level tank 9, washing tank 10 and thickener 11 decrease sequentially. The settling tank 12 is lower than the washing tank 10.

[0030] In this embodiment of the invention, a stirrer is provided in the salting tank 4, reaction tank 6, crystal growth tank 7, ground tank 8, high-level tank 9, cleaning tank 10, thickener 11 and mother liquor tank 13.

[0031] In this embodiment of the utility model, the cleaning tank 10 is a vertically arranged cylindrical structure with a conical bottom. An agitator is provided at the inner axis of the tank. The discharge port at the bottom is connected to the thickener 11 through a pipeline. The inlet at the top is connected to the high-level tank 9 and the clean water supply structure through a pipeline. The overflow port at the top is connected to the settling tank 12 through a pipeline.

[0032] Preferably, in this embodiment of the present invention, there are multiple cleaning tanks 10, which are arranged in parallel; there are multiple settling tanks 12, which are arranged in series; and the centrifugal liquid storage tank is connected to the first settling tank 12 through a pipeline.

[0033] Furthermore, in this embodiment of the present invention, the mother liquor tank 13 is connected to the phosphogypsum tank of the wet phosphoric acid production system via a pipeline with a pump 16.

[0034] The beneficial effects of the technical solution provided by this utility model embodiment are: This utility model embodiment provides a production device for high-quality sodium fluorosilicate, which adds a crystal washing process (in conjunction with pressure filtration and cooling), and the obtained sodium fluorosilicate has high purity (purity greater than 99.5%) and large crystal particles. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of an existing sodium fluorosilicate production plant.

[0036] Figure 2This is a schematic block diagram of the high-quality sodium fluorosilicate production device provided in this embodiment of the utility model;

[0037] Figure 3 This is a schematic diagram of the structure of the high-quality sodium fluorosilicate production device provided in this embodiment of the utility model;

[0038] Figure 4 This is a schematic diagram of the entire phosphorus chemical system.

[0039] In the diagram: 1 Solid-liquid separation structure, 2 Heat exchanger, 3 Fluorosilicic acid storage tank, 4 Salt dissolving tank, 5 High-level tank 1, 6 Reaction tank, 7 Crystal growth tank, 8 Ground tank, 9 High-level tank 2, 10 Cleaning tank, 11 Thickener, 12 Settling tank, 13 Mother liquor tank, 14 Pump 1, 15 Pump 2, 16 Pump 3.

[0040] A comes from the ammonium phosphate cooling tower, B comes from the tail gas treatment unit, C goes to the ammonium phosphate cooling tower, D comes from sodium sulfate, E comes from the centrifuge liquid, F goes to the gypsum tank, and G goes to the centrifuge. Detailed Implementation

[0041] To make the objectives, technical solutions and advantages of this utility model clearer, the utility model will be described in further detail below with reference to the accompanying drawings.

[0042] Example 1

[0043] See Figure 2-4 Example 1 provides a production apparatus for high-quality sodium fluorosilicate. The apparatus includes a material tank 1, a salt dissolving tank 4, a reaction tank 6, a crystal growth tank 7, a material tank 2, a thickener 11, a centrifuge, a centrifugal liquid storage tank, a washing tank 10, a settling tank 12, and a mother liquor tank 13 (specifically, a ground tank). Material tank 1 (outputting fluorosilicic acid) and salt dissolving tank 4 (used to dissolve sodium sulfate and output sodium sulfate solution) are both connected to reaction tank 6 via pipelines. Reaction tank 6 (used to react fluorosilicic acid with sodium sulfate to obtain sodium fluorosilicate), crystal growth tank 7 (used for crystal growth, consistent with existing technology), material tank 2 (used for temporary storage of reaction liquid), washing tank 10 (used for washing crystals), thickener 11 (used for thickening, consistent with existing technology), and centrifuge (used for solid-liquid separation, consistent with existing technology) are sequentially connected via pipelines. The centrifugal liquid storage tank is connected to the centrifugal liquid outlet of the centrifuge via a pipeline. The solid obtained from the centrifuge is dried and cooled to obtain sodium fluorosilicate. The overflow port of the washing tank 10 is connected to the inlet of the settling tank 12 via a pipeline. The underflow outlet at the bottom of the settling tank 12 is connected to the second material tank via a pipeline to return the crystals to the system, and the clear liquid outlet at the top is connected to the mother liquor tank 13 via a pipeline to output the clear liquid. The centrifugal liquid storage tank is connected to the inlet of the settling tank 12 via a pipeline to settle the centrifugal liquid, and the clear water inlet of the washing tank 10 is connected to the clear water supply structure (which can be clear water or cooling water, etc.) via a pipeline. The mother liquor tank 13 is connected to the phosphogypsum tank of the wet-process phosphoric acid production system via a pipeline with pump 3 16.

[0044] In this embodiment of the utility model, the cleaning tank 10 is a vertically arranged cylindrical structure with a conical bottom. An agitator is provided at the inner axis of the tank. The discharge port at the bottom is connected to the thickener 11 through a pipeline. The feed port at the top is connected to the material tank 2 (specifically the high-level tank 2 9) and the clean water supply structure through a pipeline. The overflow port at the top is connected to the settling tank 12 through a pipeline.

[0045] Example 2

[0046] See Figure 3 Example 2 provides a production apparatus for high-quality sodium fluorosilicate. The structure of this apparatus is basically the same as that of Example 1, except that there are multiple washing tanks 10 in this example, which are arranged in parallel. The inlets of the multiple washing tanks 10 are all connected to the material tank 2 (specifically, the high-level tank 2 9) and the clean water supply structure, and their overflow outlets are all connected to the settling tank 12 (specifically, the first settling tank 12) through pipelines. Their outlets are all connected to the thickener 11 through pipelines.

[0047] Example 3

[0048] See Figure 3 Example 3 provides a high-quality sodium fluorosilicate production apparatus. The structure of this apparatus is basically the same as that of Example 2, except that: in this example, there are multiple settling tanks 12, which are connected in series and descend in level. The centrifugal liquid storage tank is connected to the first settling tank 12 through a pipeline. The feed inlet of the first settling tank 12 is connected to the centrifugal liquid storage tank, the overflow outlets of multiple washing tanks 10, and the overflow outlet of the second material tank (specifically, the overflow outlet of the high-level tank 9) through a pipeline. The clear liquid outlet of the last settling tank 12 is connected to the mother liquor tank 13 through a pipeline. The underflow outlets of multiple settling tanks 12 are all connected to the second material tank (specifically, the ground tank 8) through a pipeline.

[0049] Example 4

[0050] See Figure 3 Example 4 provides a production device for high-quality sodium fluorosilicate. The structure of the device is basically the same as that of Example 3, except that there are two washing tanks 10 and two settling tanks 12 in this example.

[0051] Example 5

[0052] See Figure 2-3 Example 5 provides a high-quality sodium fluorosilicate production device. The structure of the device is basically the same as that of Example 4, except that the two cleaning tanks 10 in this example are both 2000mm in diameter and 2000mm in height, and are made of 316L material.

[0053] Example 6

[0054] See Figure 2-3 Example 6 provides a high-quality sodium fluorosilicate production apparatus. The structure of this apparatus is basically the same as that of Example 1, except that it further includes a solid-liquid separation structure 1 and a heat exchanger 2. The solid-liquid separation structure 1 is used to separate solid impurities (mainly silica gel), and the heat exchanger 2 is used for cooling (from 70-80℃ to below 50℃; the applicant found that the reaction and crystallization effects are better at 50℃). The tail gas treatment device for wet-process phosphoric acid (outputting fluorosilicic acid solution), the solid-liquid separation structure 1, the heat exchanger 2, and the material tank are connected in sequence through pipelines. The heat exchanger 2 and the cooling tower form a circulating cooling structure, and the cooling tower serves as a clean water supply structure to provide clean water to the cleaning tank 10.

[0055] Specifically, in this embodiment of the present invention, the solid-liquid separation structure 1 is a plate and frame filter press, and the heat exchanger 2 is a graphite cooler.

[0056] The properties of the prepared sodium fluorosilicate product are shown in Table 1:

[0057] Table 1

[0058]

[0059] The purity of sodium fluorosilicate is calculated on a dry basis, free acid is calculated as hydrochloric acid, sulfate is calculated as sulfate ions, and chloride is calculated as chloride ions. Products with a mesh size of 100 or higher account for more than 80%.

[0060] As can be seen from Table 1, the sodium fluorosilicate of this patent has higher purity and finer particle size.

[0061] Example 7

[0062] See Figure 2-3 Example 7 provides a high-quality sodium fluorosilicate production device. The structure of the device is basically the same as that of Example 5. The difference is that the cooling tower in this example is the cooling tower of the ammonium phosphate production device. The cooling water of the cooling tower of the ammonium phosphate production device (usually the double-effect condensate can be used as the makeup water, and the condensate is relatively clean) is relatively clean and has a slight alkalinity, which can neutralize the acidity (containing a small amount of sulfuric acid impurities).

[0063] Example 8

[0064] See Figure 2-3Example 8 provides a high-quality sodium fluorosilicate production apparatus. The structure of this apparatus is basically the same as that of Example 6, except that: in this example, the material tank includes a fluorosilicic acid storage tank 3 and an elevated tank 5. The heat exchanger 2, the fluorosilicic acid storage tank 3, the elevated tank 5, and the reaction tank 6 are connected sequentially via pipelines. The fluorosilicic acid storage tank 3 is lower than the heat exchanger 2 and the elevated tank 5, and it is connected to the elevated tank 5 via a pipeline with a pump 14. The second material tank includes a ground tank 8 and an elevated tank 9. The crystal growth tank 7, ground tank 8, elevated tank 9, and cleaning tank 10 are connected sequentially via pipelines. The overflow port at the top of elevated tank 9 is connected to the inlet of settling tank 12 via a pipeline. The underflow outlet at the bottom of settling tank 12 is connected to ground tank 8 via a pipeline. The heights of elevated tank 5, reaction tank 6, crystal growth tank 7, and ground tank 8 decrease sequentially. Ground tank 8 and mother liquor tank 13 are both lower than settling tank 12, while elevated tank 9 is higher than ground tank 8. Ground tank 8 is connected to elevated tank 9 via a pipeline with pump 15. The heights of elevated tank 9, cleaning tank 10, and thickener 11 decrease sequentially, with settling tank 12 lower than cleaning tank 10. This structure reduces the need for pumps.

[0065] In this embodiment of the invention, a stirrer is provided in the salting tank 4, reaction tank 6, crystal growth tank 7, ground tank 8, high-level tank 9, cleaning tank 10, thickener 11 and mother liquor tank 13.

[0066] In this patent, pumps, flow meters, or valves may be installed on the pipelines between the various structures as needed.

[0067] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A production apparatus for high-quality sodium fluorosilicate, comprising a material tank 1, a salt dissolving tank (4), a reaction tank (6), a crystal growth tank (7), a material tank 2, a thickener (11), a centrifuge, and a centrifugal liquid storage tank, wherein the material tank 1 and the salt dissolving tank (4) are connected to the reaction tank (6) via pipelines, and the centrifugal liquid storage tank is connected to the centrifugal liquid outlet of the centrifuge via a pipeline; characterized in that, The device also includes a cleaning tank (10), a settling tank (12), and a mother liquor tank (13); the reaction tank (6), crystal growth tank (7), material tank II, cleaning tank (10), thickener (11), and centrifuge are connected in sequence by pipelines; the overflow port of the cleaning tank (10) is connected to the inlet of the settling tank (12) by pipelines; the bottom outlet of the settling tank (12) is connected to the material tank II by pipelines, and the clear liquid outlet at the top is connected to the mother liquor tank (13) by pipelines; the centrifugal liquid storage tank is connected to the settling tank (12) by pipelines, and the clear water inlet of the cleaning tank (10) is connected to the clear water supply structure by pipelines.

2. The apparatus for producing high-quality sodium fluorosilicate according to claim 1, characterized by The device also includes a solid-liquid separation structure (1) and a heat exchanger (2). The wet-process phosphoric acid tail gas treatment device, the solid-liquid separation structure (1), the heat exchanger (2) and the material tank are connected in sequence through pipelines. The heat exchanger (2) and the cooling tower form a circulating cooling structure. The cooling tower serves as a clean water supply structure to provide clean water to the cleaning tank (10).

3. The apparatus for producing high-quality sodium fluorosilicate according to claim 2, characterized by The solid-liquid separation structure (1) is a plate and frame filter press, the heat exchanger (2) is a graphite cooler, and the cooling tower is a cooling tower of the ammonium phosphate production unit.

4. The apparatus for producing high-quality sodium fluorosilicate according to claim 2, characterized by The first material tank includes a fluorosilicic acid storage tank (3) and a high-level tank (5). The heat exchanger (2), the fluorosilicic acid storage tank (3), the high-level tank (5), and the reaction tank (6) are connected in sequence by pipelines. The fluorosilicic acid storage tank (3) is lower than the heat exchanger (2) and the high-level tank (5), and it is connected to the high-level tank (5) by a pipeline with a pump (14). The second material tank includes a ground tank (8) and a high-level tank (9). The crystal growth tank (7), the ground tank (8), the high-level tank (9), and the cleaning tank (10) are connected in sequence by pipelines. The overflow port at the top of the high-level tank (9) is connected to the settling tank (6) by a pipeline. The feed inlet of the settling tank (12) is connected to the bottom outlet of the settling tank (12) and connected to the ground tank (8) through a pipeline. The heights of the high-level tank (5), reaction tank (6), crystal growth tank (7) and ground tank (8) decrease in sequence. The ground tank (8) and mother liquor tank (13) are both lower than the settling tank (12). The high-level tank (9) is higher than the ground tank (8). The ground tank (8) is connected to the high-level tank (9) through a pipeline with pump (15). The heights of the high-level tank (9), washing tank (10) and thickener (11) decrease in sequence. The settling tank (12) is lower than the washing tank (10).

5. The apparatus for producing high-quality sodium fluorosilicate according to claim 4, characterized by Agitators are provided in the salting tank (4), reaction tank (6), crystal growth tank (7), ground tank (8), high-level tank II (9), cleaning tank (10), thickener (11) and mother liquor tank (13).

6. The apparatus for producing high-quality sodium fluorosilicate according to claim 4, characterized by The cleaning tank (10) is a vertically arranged cylindrical structure with a conical bottom. An agitator is provided at the inner axis of the tank. The discharge port at the bottom is connected to the thickener (11) through a pipeline. The inlet at the top is connected to the high-level tank (9) and the clean water supply structure through a pipeline. The overflow port at the top is connected to the settling tank (12) through a pipeline.

7. The apparatus for producing high-quality sodium fluorosilicate according to claim 1, wherein There are multiple cleaning tanks (10), and multiple cleaning tanks (10) are arranged in parallel; there are multiple settling tanks (12), and multiple settling tanks (12) are arranged in series; the centrifugal liquid storage tank is connected to the first settling tank (12) through a pipeline.

8. The apparatus for producing high-quality sodium fluorosilicate according to claim 1, wherein The mother liquor tank (13) is connected to the phosphogypsum tank of the wet phosphoric acid production system via a pipeline with pump three (16).

Images