A production line for converting dihydrate and anhydrite gypsum

Abstract

The utility model provides a kind of dihydrate phosphogypsum and anhydrous phosphogypsum conversion production line, including dihydrate phosphogypsum reaction tank, flotation machine, belt filter, feed tank, conversion tank and turbulent washing filter press are connected in turn by cascade pipe, turbulent washing filter press and washing liquid collecting tank are also connected by cascade pipe, scale pipe is connected between belt filter and washing liquid collecting tank, cascade pipe and scale pipe are equipped with transfer pump.The utility model discloses technical scheme, in the process of making dihydrate phosphogypsum into anhydrous phosphogypsum, washing liquid generated by turbulent washing filter press is moved to belt filter, sulfuric acid is retained in washing liquid, sulfate is generated by chemical reaction of sulfuric acid and potassium fluosilicate, sodium fluosilicate, iron phosphate and aluminum phosphate etc., calcium sulfate dihydrate is also removed from crystallization water by sulfuric acid, sulfate is dissolved in water, and the production line is maintained continuously and stably running, and the production efficiency is improved.

Description

Technical Field

[0001] This utility model belongs to the field of anhydrous phosphogypsum production technology, and in particular, a production line for the conversion of dihydrate phosphogypsum and anhydrous phosphogypsum. Background Technology

[0002] Dihydrate phosphogypsum is an industrial byproduct of the wet process for producing phosphoric acid, with its main component being calcium sulfate dihydrate, accounting for approximately 90%. Due to the influence of the preparation process, dihydrate phosphogypsum is strongly acidic and contains phosphorus, fluorine, organic matter, and some radioactive elements. The presence of impurities and radioactive elements in dihydrate phosphogypsum, as well as the instability caused by different phosphate rock types, restricts its comprehensive utilization. This leads to dihydrate phosphogypsum primarily being disposed of through open-air stockpiling, which not only occupies a large amount of land and wastes resources, but also causes harmful impurities to leach out with rainwater, generating acidic wastewater and causing serious pollution and ecological damage to soil, water systems, and the atmosphere. In contrast, anhydrous phosphogypsum has a calcination temperature of 500-700℃, contains fewer impurities, and has more stable properties than dihydrate phosphogypsum. It has the advantages of high waste utilization rate and high early strength in the preparation of cementitious materials. Therefore, industrial processes often employ technical methods to convert dihydrate phosphogypsum into anhydrous phosphogypsum.

[0003] For example, patent document CN110627391B discloses a highly active anhydrous phosphogypsum cementitious material and its preparation method. It comprises 75-95 parts anhydrous phosphogypsum, 4-20 parts alkaline activator, 1-10 parts sulfate, and 0.15-0.95 parts water-reducing agent. The anhydrous phosphogypsum, alkaline activator, and sulfate are added to a mixer and mixed to ensure uniform dispersion. Water is then added, along with the water-reducing agent, and the mixture is stirred until uniformly dispersed to obtain the anhydrous phosphogypsum cementitious material. This patented technology improves waste utilization efficiency and reduces pollution from industrial solid wastes such as carbide slag and white mud.

[0004] Figure 1This diagram illustrates a common existing production line for the conversion of dihydrate phosphogypsum to anhydrous phosphogypsum. The production line includes a dihydrate phosphogypsum reaction tank, a flotation machine, a belt filter, a feed tank, a crystallization tank, a turbulent scrubbing filter press, and a return pipe. The dihydrate phosphogypsum reaction tank, flotation machine, belt filter, feed tank, crystallization tank, and turbulent scrubbing filter press are connected in series via cascade pipes. To improve the conversion efficiency of the components in the dihydrate phosphogypsum, the turbulent scrubbing filter press is also connected to the filtrate collection tank via cascade pipes. The return pipe is connected between the dihydrate phosphogypsum reaction tank and the filtrate collection tank. The cascade pipes and the return pipe... Equipped with a transfer pump, the existing dihydrate phosphogypsum and anhydrous phosphogypsum conversion production line is used. The dihydrate phosphogypsum and raw liquid are first mixed in the dihydrate phosphogypsum reaction tank to obtain a dihydrate slurry. Then, the dihydrate slurry is mixed with flotation agent in a flotation machine to obtain scum and foam. The scum is then filtered in a belt filter to obtain a filter cake and dihydrate filtrate. The filter cake is then fed into a crystallization tank via a feed trough, where it is mixed with concentrated sulfuric acid. After crystallization treatment, a composite material containing anhydrous phosphogypsum is obtained. The composite material is then washed in a turbulent washing filter press to obtain anhydrous phosphogypsum and filtrate.

[0005] However, in existing dihydrate phosphogypsum and anhydrous phosphogypsum conversion production lines, the filter cake produced by the belt filter often cannot be transferred to the crystallization tank for crystal conversion in a timely, thorough and complete manner. The residual components in the belt filter often accumulate inside, causing scaling and clogging of the belt filter. The production process has to be interrupted, and production can only continue after the scale inside the belt filter is cleaned. This seriously disrupts the production process rhythm and affects the company's production efficiency. Utility Model Content

[0006] To solve the above-mentioned technical problems, this utility model provides a production line for the conversion of dihydrate phosphogypsum and anhydrous phosphogypsum.

[0007] This utility model is achieved through the following technical solution.

[0008] This utility model provides a production line for the conversion of dihydrate phosphogypsum and anhydrous phosphogypsum, including a dihydrate phosphogypsum reaction tank, a flotation machine, a belt filter, a feeding tank, a crystallization tank, a turbulent washing filter press, and a scale removal pipe. The dihydrate phosphogypsum reaction tank, flotation machine, belt filter, feeding tank, crystallization tank, and turbulent washing filter press are connected in series via a cascade pipe. The turbulent washing filter press and the washing liquid collection tank are also connected via the cascade pipe. The scale removal pipe is connected between the belt filter and the washing liquid collection tank. A transfer pump is provided on the cascade pipe and the scale removal pipe.

[0009] The dihydrate phosphogypsum and anhydrous phosphogypsum conversion production line also includes a filtrate collection tank, a return pipe, and a descaling pipe. The filtrate collection tank is connected to the turbulent washing filter press via the cascade pipe. The return pipe is connected between the dihydrate phosphogypsum reaction tank and the filtrate collection tank. The transfer pump is also installed on the return pipe. The descaling pipe is connected between the feed tank and the return pipe.

[0010] The production line for converting dihydrate phosphogypsum and anhydrous phosphogypsum also includes a scale discharge pipe, which is connected between the feed tank and the scale removal pipe.

[0011] A reverse flushing pipe is also connected between the flotation machine and the belt filter, and the conveying pump is also installed on the reverse flushing pipe.

[0012] The dihydrate phosphogypsum reaction tank is also connected to the belt filter by a filtrate feedback pipe, and a transfer pump is also installed on the filtrate feedback pipe.

[0013] A foam feedback pipe is also connected between the dihydrate phosphogypsum reaction tank and the flotation machine, and a transfer pump is also installed on the foam feedback pipe.

[0014] The transfer pump is a booster pump.

[0015] The production line for converting dihydrate phosphogypsum to anhydrous phosphogypsum also includes a fluorine recovery chamber, which is connected to the dihydrate phosphogypsum reaction tank and the crystallization tank by extraction tubes.

[0016] The production line for converting dihydrate phosphogypsum and anhydrous phosphogypsum also includes a storage chamber, and a transfer machine is provided between the turbulent washing filter press and the storage chamber.

[0017] The transfer machine is a belt conveyor.

[0018] The beneficial effects of this utility model are as follows: Analysis shows that the main components of the dirt deposited in the belt filter include potassium fluorosilicate, sodium fluorosilicate, calcium sulfate dihydrate, ferric phosphate, and aluminum phosphate. Using the technical solution of this utility model, since a large amount of concentrated sulfuric acid is needed to convert dihydrate phosphogypsum into anhydrous phosphogypsum through crystal transformation in the crystallization tank, and sulfuric acid remains in the washing liquid after the anhydrous phosphogypsum is washed by the turbulent washing filter press, when the washing liquid from the turbulent washing filter press is transferred to the belt filter, the sulfuric acid reacts with potassium fluorosilicate, sodium fluorosilicate, ferric phosphate, and aluminum phosphate to generate sulfates. In addition, sulfuric acid has extremely strong dehydrating properties, enabling the calcium sulfate dihydrate to dehydrate and generate sulfates, which dissolve in water. This prevents potassium fluorosilicate, sodium fluorosilicate, ferric phosphate, and aluminum phosphate from precipitating or depositing in the belt filter, avoiding blockage inside the belt filter, maintaining a continuous and stable production process, and improving enterprise production efficiency. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the existing technology for the conversion of dihydrate phosphogypsum to anhydrous phosphogypsum production line; Figure 2 This is a schematic diagram of the structure of the production line for the conversion of dihydrate phosphogypsum and anhydrous phosphogypsum according to this utility model.

[0020] In the diagram: 1-Dihydrate phosphogypsum reaction tank, 2-Flotation machine, 3-Belt filter, 4-Feed tank, 5-Crystallization tank, 6-Turbulent washing filter press, 7-Scale removal pipe, 8-Transfer machine, 9-With transfer pump, 10-Washing liquid collection tank, 11-Filtrate collection tank, 12-Recirculation pipe, 13-Descaling pipe, 14-Scale discharge pipe, 15-Reverse flushing pipe, 16-Filtrate feedback pipe, 17-Foam feedback pipe, 18-Fluorine recovery chamber, 19-Storage chamber, 20-Cascade pipe, 21-Extraction pipe. Detailed Implementation

[0021] The technical solution of this utility model is further described below, but the scope of protection is not limited thereto.

[0022] like Figure 1 and Figure 2 As shown, this utility model provides a production line for the conversion of dihydrate phosphogypsum and anhydrous phosphogypsum, including a dihydrate phosphogypsum reaction tank 1, a flotation machine 2, a belt filter 3, a feed tank 4, a crystallization tank 5, a turbulent washing filter press 6, and a scale removal pipe 7. The dihydrate phosphogypsum reaction tank 1, flotation machine 2, belt filter 3, feed tank 4, crystallization tank 5, and turbulent washing filter press 6 are connected in series via a cascade pipe 20. The turbulent washing filter press 6 is also connected to a washing liquid collection tank 10 via the cascade pipe 20. The scale removal pipe 7 is connected between the belt filter 3 and the washing liquid collection tank 10. A transfer pump 9 is provided on the cascade pipe 20 and the scale removal pipe 7. The scale removal pipe 7 is used to return the washing liquid generated by the turbulent washing filter press 6 to the belt filter 3, and the washing liquid is used to remove the deposited dirt in the belt filter 3.

[0023] Analysis revealed that the main components of the deposits inside the belt filter included potassium fluorosilicate, sodium fluorosilicate, calcium sulfate dihydrate, ferric phosphate, and aluminum phosphate. This invention addresses this issue by using a large amount of concentrated sulfuric acid to convert dihydrate phosphogypsum into anhydrous phosphogypsum in the crystallization tank. Even after the anhydrous phosphogypsum is washed in a turbulent washing filter press, sulfuric acid remains in the washing liquid. When the washing liquid from the turbulent washing filter press is transferred to the belt filter, the sulfuric acid reacts with potassium fluorosilicate, sodium fluorosilicate, ferric phosphate, and aluminum phosphate to form sulfates. Furthermore, sulfuric acid has strong dehydrating properties, enabling the dehydration of calcium sulfate dihydrate to form sulfates, which dissolve in water. This prevents the precipitation or deposition of potassium fluorosilicate, sodium fluorosilicate, ferric phosphate, and aluminum phosphate inside the belt filter, avoiding blockage and maintaining a continuous and stable production process, thus improving enterprise production efficiency.

[0024] Specifically, the production line for converting dihydrate phosphogypsum to anhydrous phosphogypsum also includes a filtrate collection tank 11, a return pipe 12, and a descaling pipe 13. The filtrate collection tank 11 is connected to the turbulent washing filter press 6 via a cascade pipe 20. The return pipe 12 is connected between the dihydrate phosphogypsum reaction tank 1 and the filtrate collection tank 11. A transfer pump 9 is also installed on the return pipe 12. The descaling pipe 13 is connected between the feed tank 4 and the return pipe 12. The return pipe 12 is used to return the filtrate generated by the turbulent washing filter press 6 to the dihydrate phosphogypsum reaction tank 1, and the descaling pipe 13 is used to return the filtrate generated by the turbulent washing filter press 6 to the feed tank 4. The filtrate is used to remove the deposited dirt in the feed tank 4. By adopting the technical solution of this utility model, some sulfuric acid is still retained in the filtrate produced by the turbulent washing filter press 6. The sulfuric acid in the filtrate can be used to further remove the deposited dirt in the feed tank 4, thereby ensuring that the conversion production process from dihydrate phosphogypsum to anhydrous phosphogypsum remains continuous and stable, and further improving the production efficiency of the enterprise.

[0025] In addition, the conversion production line for dihydrate phosphogypsum and anhydrous phosphogypsum also includes a scale discharge pipe 14, which is connected between the feed tank 4 and the scale removal pipe 7. A reverse flushing pipe 15 is also connected between the flotation machine 2 and the belt filter 3, and a transfer pump 9 is also installed on the reverse flushing pipe 15, preferably a booster pump. Using the technical solution of this utility model, the reverse flushing pipe 15 is used to transfer the secondary filtrate into the flotation machine 2, and utilizes the force generated when the dihydrate filtrate flows back to cause the scum adhering to the inner wall of the flotation machine 2 to fall back into the flotation machine 2, avoiding blockage inside the flotation machine 2, and further ensuring the continuous and stable conversion production process from dihydrate phosphogypsum to anhydrous phosphogypsum.

[0026] Furthermore, a filtrate feedback pipe 16 is connected between the dihydrate phosphogypsum reaction tank 1 and the belt filter 3, and a transfer pump 9 is also installed on the filtrate feedback pipe 16. A foam feedback pipe 17 is also connected between the dihydrate phosphogypsum reaction tank 1 and the flotation machine 2, and the transfer pump 9 is also installed on the foam feedback pipe 17. By adopting the technical solution of this utility model and setting up the filtrate feedback pipe 16 and the foam feedback pipe 17, the conversion efficiency of dihydrate phosphogypsum to anhydrous phosphogypsum is improved, and waste of raw materials is avoided.

[0027] Specifically, the production line for the conversion of dihydrate phosphogypsum to anhydrous phosphogypsum also includes a fluorine recovery chamber 18, which is connected to the dihydrate phosphogypsum reaction tank 1 and the crystallization tank 5 via extraction pipes 21. Because fluorine and silicon dioxide in phosphate rock generate fluorosilicic acid during the reaction stage, and fluorosilicic acid combines with metal cations such as potassium and sodium in the slurry to form potassium fluorosilicate or sodium fluorosilicate, the solubility of potassium fluorosilicate or sodium fluorosilicate decreases sharply with decreasing temperature. When the dihydrate slurry enters the lower-temperature area inside the belt filter, fluorosilicates quickly reach supersaturation and precipitate in large quantities, forming hard white crystalline scale. This scale often mixes with calcium sulfate scale, greatly exacerbating clogging. By using the technical solution of this invention, the fluorine recovery chamber 18 is set up to extract fluorine-containing components from the dihydrate slurry and filtrate in a timely manner, thereby preventing the formation of white crystalline scale and further ensuring the continuous and stable conversion process of dihydrate phosphogypsum to anhydrous phosphogypsum.

[0028] In addition, the dihydrate phosphogypsum to anhydrous phosphogypsum conversion production line also includes a storage chamber 19, and a transfer machine 8 is provided between the turbulent washing filter press 6 and the storage chamber 19. Preferably, the transfer machine 8 is a belt conveyor.

[0029] Furthermore, when the dihydrate phosphogypsum and anhydrous phosphogypsum conversion production line provided by this utility model is running, the conversion process of dihydrate phosphogypsum and anhydrous phosphogypsum includes the following steps: Step 1: Using the dihydrate phosphogypsum and anhydrous phosphogypsum conversion production line as described above, the dihydrate phosphogypsum and the original solution are mixed in the dihydrate phosphogypsum reaction tank 1 to obtain a dihydrate slurry. Step 2: After mixing and flotating the dihydrate slurry and flotation agent in the flotation machine 2, scum and foam are obtained; Step 3: After filtering the scum from Step 2 in belt filter 3, filter cake and dihydrate filtrate are obtained; Step 4: The filter cake from Step 3 is fed into the crystallization tank 5 via the feed trough 4, and the filter cake is mixed with concentrated sulfuric acid in the crystallization tank 5. After crystallization treatment, a combined material containing anhydrous phosphogypsum is obtained. Step 5: After washing the combined material from Step 4 in the turbulent washing filter press 6, anhydrous phosphogypsum and washing liquid are obtained; Step 6: Use the washing solution from Step 5 to rinse the inside of the belt filter 3 to remove the deposited dirt adhering to the belt filter 3.

[0030] By adopting the technical solution of this utility model, since a large amount of concentrated sulfuric acid is required to convert dihydrate phosphogypsum into anhydrous phosphogypsum through crystal conversion in the crystallization tank, sulfuric acid is still retained in the washing liquid after the anhydrous phosphogypsum is washed by the turbulent washing filter press. When the washing liquid generated by the turbulent washing filter press is transferred to the belt filter, the sulfuric acid reacts with substances such as potassium fluorosilicate, sodium fluorosilicate, ferric phosphate, and aluminum phosphate to generate sulfate. In addition, sulfuric acid also has extremely strong dehydrating properties, which can dehydrate calcium sulfate dihydrate to generate sulfate. The sulfate dissolves in water, thereby preventing substances such as potassium fluorosilicate, sodium fluorosilicate, ferric phosphate, and aluminum phosphate from precipitating or depositing in the belt filter, avoiding blockage inside the belt filter, maintaining a continuous and stable production process, and improving the production efficiency of the enterprise.

[0031] Specifically, in step six, the deposited dirt still adheres to the inside of the feeding tank 4. The conversion process of dihydrate phosphogypsum and anhydrous phosphogypsum also includes the following steps: In step five, the composite material and lime are neutralized in a turbulent washing filter press 6 to obtain anhydrous filtrate. A portion of the anhydrous filtrate is transferred to a dihydrate reaction tank for reuse. A portion of the anhydrous filtrate and the washing liquid from step five are used to rinse the inside of the feed tank 4 to remove the deposited dirt adhering to the feed tank 4.

[0032] Furthermore, in step five, the composite material is washed at least three times in the turbulent washing filter press 6. The washing liquid is the liquid material produced after the first washing of the composite material in the turbulent washing filter press 6. By adopting the technical solution of this utility model, since the washing liquid is selected from the liquid material produced after the first washing, it contains a higher concentration of sulfuric acid, typically reaching 15%. This effectively removes the deposited dirt in the belt filter, ensuring a continuous and stable production process.

[0033] Specifically, the conversion process of dihydrate phosphogypsum and anhydrous phosphogypsum also includes the following steps: transferring the dihydrate filtrate from step three into the flotation machine 2, and using the force generated when the dihydrate filtrate is refluxed to cause the scum adhering to the inner wall of the flotation machine 2 to fall back into the flotation machine 2.

[0034] In addition, the deposited dirt includes potassium fluorosilicate, sodium fluorosilicate, calcium sulfate dihydrate, ferric phosphate, and aluminum phosphate; both the washing solution and the anhydrous filtrate include sulfuric acid; and the deposited dirt removal steps include the following chemical reaction processes: K₂SiF₆ + H₂SO₄ → 2KHSO₄ + H₂SiF₆; Na2SiF6+H2SO4→2NaHSO4+H2SiF6; CaSO4·2H2O+H2SO4→CaSO4+H2SO4+2H2O; 2FePO4+3H2SO4→Fe2(SO4)3+2H3PO4; 2AlPO4+3H2SO4→Al2(SO4)3+2H3PO4.

[0035] Specifically, potassium fluorosilicate or sodium fluorosilicate reacts very thoroughly in high-concentration sulfuric acid, producing fluorosilicic acid, a strong acid soluble in water. Potassium bisulfate or sodium bisulfate also has high solubility. Therefore, the originally hardened fluorosilicate scale layer will be rapidly dissolved in sulfuric acid with a concentration exceeding 12%, becoming a soluble ionic state, completely preventing fluorosilicate scaling.

[0036] Sulfuric acid exists in an ionic state in solution. The large number of sulfate ions in the solution generates a strong common ion effect, which greatly inhibits the dissolution of calcium sulfate. Both dihydrate and hemihydrate calcium sulfate contain water of crystallization. Concentrated sulfuric acid has a strong dehydrating property. Concentrated sulfuric acid removes the water of crystallization from these hydrated calcium sulfates, converting them into anhydrous calcium sulfate. Although anhydrous calcium sulfate is not easily soluble in water, the anhydrous calcium sulfate crystals will make the originally dense scale layer loose, porous, and produce microcracks. At the same time, concentrated sulfuric acid also has a dissolving effect on components such as ferric hydroxide that may exist between the scale layer and the metal substrate, which have a "bonding bridge" effect. Ultimately, the hard scale layer becomes loose, and the adhesion is greatly reduced. Thus, under the action of hydraulic or other external forces, it peels off the inner wall of the belt filter, avoids the internal blockage of the belt filter, and ensures that the production process remains continuous and stable.

[0037] The sulfate and hydrogen ions produced by sulfuric acid in the solution can effectively dissolve insoluble iron phosphate and aluminum phosphate, generating soluble iron ions, aluminum ions and phosphoric acid. This chemical reaction process further destroys the components in the scale layer that have a "bonding bridge" effect, causing the entire scale layer to disintegrate and preventing clogging inside the belt filter, thus ensuring that the production process remains continuous and stable.

[0038] Furthermore, the conversion process between dihydrate phosphogypsum and anhydrous phosphogypsum also includes the following steps: transferring the foam from step two to the dihydrate reaction tank for reuse; transferring the dihydrate filtrate from step three to the dihydrate reaction tank for reuse; and extracting and reusing the fluorine-containing substances in the dihydrate reaction tank and crystallization tank.

Claims

1. A production line for the conversion of dihydrate phosphogypsum and anhydrous phosphogypsum, characterized in that: The system includes a dihydrate phosphogypsum reaction tank (1), a flotation machine (2), a belt filter (3), a feed tank (4), a crystallization tank (5), a turbulent washing filter press (6), and a scale removal pipe (7). The dihydrate phosphogypsum reaction tank (1), flotation machine (2), belt filter (3), feed tank (4), crystallization tank (5), and turbulent washing filter press (6) are connected in series via a cascade pipe (20). The turbulent washing filter press (6) is also connected to the washing liquid collection tank (10) via the cascade pipe (20). The scale removal pipe (7) is connected between the belt filter (3) and the washing liquid collection tank (10). A transfer pump (9) is provided on the cascade pipe (20) and the scale removal pipe (7).

2. The production line for the conversion of dihydrate phosphogypsum and anhydrous phosphogypsum as described in claim 1, characterized in that: The dihydrate phosphogypsum and anhydrous phosphogypsum conversion production line also includes a filtrate collection tank (11), a return pipe (12), and a descaling pipe (13). The filtrate collection tank (11) is connected to the turbulent washing filter press (6) through the cascade pipe (20). The return pipe (12) is connected between the dihydrate phosphogypsum reaction tank (1) and the filtrate collection tank (11). The transfer pump (9) is also installed on the return pipe (12). The descaling pipe (13) is connected between the feed tank (4) and the return pipe (12).

3. The production line for the conversion of dihydrate phosphogypsum and anhydrous phosphogypsum as described in claim 1, characterized in that: The production line for converting dihydrate phosphogypsum to anhydrous phosphogypsum also includes a scale discharge pipe (14), which is connected between the feed tank (4) and the scale removal pipe (7).

4. The production line for the conversion of dihydrate phosphogypsum and anhydrous phosphogypsum as described in claim 1, characterized in that: A reverse flushing pipe (15) is also connected between the flotation machine (2) and the belt filter (3), and the transfer pump (9) is also installed on the reverse flushing pipe (15).

5. The production line for the conversion of dihydrate phosphogypsum and anhydrous phosphogypsum as described in claim 1, characterized in that: The dihydrate phosphogypsum reaction tank (1) is also connected to the belt filter (3) by a filtrate feedback pipe (16), and the transfer pump (9) is also installed on the filtrate feedback pipe (16).

6. The production line for the conversion of dihydrate phosphogypsum and anhydrous phosphogypsum as described in claim 1, characterized in that: A foam feedback pipe (17) is also connected between the dihydrate phosphogypsum reaction tank (1) and the flotation machine (2), and a transfer pump (9) is also installed on the foam feedback pipe (17).

7. A production line for the conversion of dihydrate phosphogypsum and anhydrous phosphogypsum as described in claim 1, 2, 4, 5, or 6, characterized in that: The transfer pump (9) is a booster pump.

8. The production line for the conversion of dihydrate phosphogypsum and anhydrous phosphogypsum as described in claim 1, characterized in that: The dihydrate phosphogypsum and anhydrous phosphogypsum conversion production line also includes a fluorine recovery chamber (18), which is connected to the dihydrate phosphogypsum reaction tank (1) and the crystal conversion tank (5) by an extraction tube (21).

9. The production line for the conversion of dihydrate phosphogypsum and anhydrous phosphogypsum as described in claim 1, characterized in that: The dihydrate phosphogypsum and anhydrous phosphogypsum conversion production line also includes a storage tank (19), and a transfer machine (8) is provided between the turbulent washing filter press (6) and the storage tank (19).

10. The production line for the conversion of dihydrate phosphogypsum and anhydrous phosphogypsum as described in claim 9, characterized in that: The transfer machine (8) is a belt conveyor.

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