System and method for producing ammonium sulfite from electrolytic manganese ammonium sulfate double salt

Abstract

The invention discloses a system and a method for producing ammonium sulfite by using electrolytic manganese ammonium sulfate double salt, which are characterized in that the calcination effect is improved through the pretreatment of drying, crushing and the like, and the ammonium sulfate is finally converted into sulfur dioxide through the calcination in an oxygen-free environment to prepare the ammonium sulfite. The difference is that a direct blending and calcining mode is adopted for treatment at home and abroad, but the method cannot be popularized and applied technically and economically, after ammonium sulfate in the ammonium sulfate double salt is decomposed, a high-value ammonium sulfite product can be produced by adopting the mode, and the method is high in technical feasibility and low in cost. And the residual high-manganese-content substance can be used for producing electrolytic manganese metal by an electrolytic manganese system, so that certain economic benefits can be generated, and huge environmental protection benefits and safety guarantee are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of preparing ammonium sulfite, and specifically to a system and method for producing ammonium sulfite using electrolytic manganese ammonium sulfate double salt. Background Art

[0002] During the production process of electrolytic manganese, ammonium sulfate is generated. The production of ammonium sulfite from ammonium sulfate mainly involves reactions with substances such as sulfur dioxide. The electrolytic manganese ammonium sulfate double salt contains about 45% of ammonium sulfate. Since this type of double salt is a mixture of sulfates such as ammonium sulfate, manganese sulfate, magnesium sulfate, and calcium sulfate, the ammonium sulfate therein cannot be directly utilized, resulting in the stacking of such mixtures. To solve this problem, the present patent provides a system and method for producing ammonium sulfite using electrolytic manganese ammonium sulfate double salt. Summary of the Invention

[0003] The purpose of the present invention is to provide a system and method for producing ammonium sulfite using electrolytic manganese ammonium sulfate double salt to solve the problems raised in the above background art.

[0004] To achieve the above purpose, the present invention provides the following technical solutions: A system for producing ammonium sulfite using electrolytic manganese ammonium sulfate double salt includes a drum high-temperature drying device. The electrolytic manganese ammonium sulfate mixture output from the drum high-temperature drying device is sent to a crushing device through a hoist. The electrolytic manganese ammonium sulfate mixture output from the crushing device is sent to an anaerobic calcination furnace. The rear end of the furnace of the anaerobic calcination furnace is connected to a three-stage electrostatic precipitator. The tail gas is sent to a multi-stage absorption and conversion tower through a tail gas pipeline after being dust-removed by the three-stage electrostatic precipitator. The conversion liquid and the absorption completed liquid after passing through the multi-stage absorption and conversion tower are sent to an evaporation device. The concentrated liquid output from the evaporation device is processed by a cooling crystallization device to form a crystal slurry, and the crystal slurry is separated by a separation device to separate out ammonium nitrite.

[0005] As a further scheme of the present invention: The crushing device is equipped with a filter screen device to control the particle size of the crushed electrolytic manganese ammonium sulfate mixture within a certain mesh size.

[0006] As a further scheme of the present invention: The multi-stage absorption and conversion tower consists of a spray tower a, a spray tower b, a spray tower c, a series pipeline, and an absorbent pipeline. The tail gas outlet of the spray tower a is connected to the tail gas inlet of the spray tower b through the series pipeline. The tail gas outlet of the spray tower b is connected to the tail gas inlet of the spray tower c through the series pipeline. The absorption liquid of the spray tower c is transported to the spray tower b through the absorbent pipeline. The absorption liquid of the spray tower b is transported to the spray tower a through the absorbent pipeline.

[0007] As a further scheme of the present invention: The conversion liquid and the absorption completed liquid output from the spray tower a are sent to the evaporation device through a completed liquid pipeline. The mother liquid output from the separation device is sent to the evaporation device through a mother liquid pipeline.

[0008] As a further solution of the present invention: absorbent addition pipelines are provided on the spray towers a, b, and c, and a spraying device is arranged inside the spray towers a, b, and c. The absorbent and the absorbent liquid are evenly sprayed into the spray towers by spraying.

[0009] As a further solution of the present invention: the tail gas output end of the spray tower c is communicated with the tail gas pipeline through a tail gas reflux pipeline.

[0010] A method for producing ammonium sulfite using this system includes the following steps; S1: The electrolytic manganese ammonium sulfate mixture is put into a drum high-temperature drying device and dried at 150 °C to remove moisture. S2: The dried mixture in S1 is crushed and sieved to 50 meshes through a crushing device so that the heat pyrolysis during anaerobic calcination is uniform. S3: The sieved mixture in S2 is sent to an anaerobic calcination furnace for anaerobic calcination and decomposition. S4: The tail gas generated by the anaerobic calcination in S3 is subjected to dust removal treatment through a three-stage electrostatic precipitator connected to the rear end of the anaerobic calcination furnace. S5: The tail gas after the dust removal treatment in S4 is sent into the tail gas pipeline and then into a multi-stage absorption and conversion tower. S6: The spray towers a, b, and c are connected in series. Absorbents are sprayed in the spray towers a, b, and c, and the tail gas is successively absorbed. The rear end of the spray tower c is connected to a tail gas treatment device and an evacuation device. S7: The three spray towers continuously spray and wash. After the ammonium sulfite concentration in the spray tower a reaches 80 g / L, it is discharged to an evaporation device for low-temperature evaporation. S8: The absorbent liquid in the spray tower b is pumped into the spray tower a, the absorbent liquid in the spray tower c is pumped into the spray tower b, and a new absorbent is added to the spray tower c for reaction. The qualified liquid is discharged from the spray tower. S9: After the qualified liquid is discharged, it enters a low-temperature evaporation crystallizer for evaporation and crystallization. The produced pure water is used to prepare the absorbent liquid, and the solid product is dried and then packaged, which is the target product of this time.

[0011] As a further solution of the present invention: the mixture is sent to the anaerobic calcination furnace for anaerobic calcination and decomposition at 550 - 600 °C for 0.2 - 2 hours.

[0012] As a further solution of the present invention: the absorbent is ammonia water. 8 moles of ammonia water are added to the spray tower a, 6 moles of ammonia water are added to the spray tower b, and 4 moles of ammonia water are added to the spray tower c.

[0013] Compared with the prior art, the beneficial effects of the present invention are: The system and method for producing ammonium sulfite using the ammonium sulfate double salt of electrolytic manganese. Through pre-treatments such as drying and crushing, the calcination effect is improved in this application. By calcining in an anaerobic environment, the ammonium sulfate is finally converted into sulfur dioxide and then ammonium sulfite is prepared. The difference is that at home and abroad, the method of direct blending and calcination is used for treatment, but it has not been popularized and applied technically and economically. After the ammonium sulfate in the ammonium sulfate double salt of this application decomposes, the above method can be used to produce high-value ammonium sulfite products, and the technical feasibility is high. The substances with a high manganese content remaining can be used in the electrolytic manganese system to produce electrolytic metal manganese, which will not only generate certain economic benefits, but also have great environmental protection benefits and safety guarantees. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a process diagram of a system and method for producing ammonium sulfite using the ammonium sulfate double salt of electrolytic manganese.

[0015] In the figure: 1. Drum high-temperature drying device; 2. Raw material inlet; 3. Drying gas pipeline; 4. Hoist; 5. Filter sieve device; 6. Crushing device; 7. Anaerobic calciner; 8. Three-stage electrostatic precipitator; 9. Tail gas pipeline; 10. Spray tower a; 11. Tail gas reflux pipeline; 12. Series pipeline; 13. Absorbent addition pipeline; 14. Delivery pipeline; 15. Finished liquid pipeline; 16. Spray tower b; 17. Absorbent pipeline; 18. Spray tower c; 19. Mother liquor pipeline; 20. Cooling and crystallization equipment; 21. Product pipeline; 22. Evaporation equipment; 23. Crystal slurry pipeline; 24. Separation equipment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] Please refer to Figure 1, in the embodiments of the present invention, a system for producing ammonium sulfite using an ammonium sulfate complex of electrolytic manganese includes a drum high-temperature drying device 1. The ammonium sulfate complex of electrolytic manganese is put into the drum high-temperature drying device 1 and dried to remove moisture at 150°C. Under the drying condition of 150°C, some oxidation reactions may occur to the ammonium sulfate complex of electrolytic manganese. Manganese may be oxidized by oxygen in the air to form low-valent oxides such as MnO, and ammonium sulfate will decompose to a certain extent at 150°C. Ammonium sulfate will gradually decompose to produce ammonia and ammonium bisulfate. Therefore, the drying time should not be too long and should be controlled within a relatively short time. The drum high-temperature drying device 1 is provided with a raw material inlet 2 and a drying gas pipeline 3. The drying gas pipeline 3 is discharged from the raw material inlet 2 and collected for treatment in a three-stage electrostatic precipitator 8. The ammonium sulfate complex of electrolytic manganese output by the drum high-temperature drying device 1 is sent to a crushing device 6 through a hoist 4. The ammonium sulfate complex of electrolytic manganese output by the crushing device 6 is sent to an anaerobic calcination furnace 7. The dried mixture is crushed and screened to 50 meshes through the crushing device 6 so that the heat pyrolysis during anaerobic calcination is uniform. The mixture is sent to the anaerobic calcination furnace 7 for anaerobic calcination decomposition at 550 - 600°C for 0.2 - 2 hours. The rear end of the furnace of the anaerobic calcination furnace 7 is connected to the three-stage electrostatic precipitator 8. MnO is calcined at 550 - 600°C under anaerobic conditions to produce manganese tetroxide and a small amount of oxygen. The reaction formula is as follows: Manganese tetroxide can be recycled; NH4HSO4 decomposes upon heating to ammonia and sulfuric acid That is: NH4HSO4 → NH3↑ + H2SO4; Since the temperature is 550 - 600°C, sulfuric acid will further decompose into sulfur trioxide and water H2SO4 → SO3↑ + H2O; The overall reaction equation is: NH4HSO4 → NH3↑ + SO3↑ + H2O; SO3↑ is unstable under high-temperature conditions and will undergo a decomposition reaction to form. The anaerobic calcination furnace 7 in the calcination environment of 550 - 600°C is sufficient to satisfy the high-temperature decomposition of sulfur trioxide to produce sulfur dioxide and oxygen; That is: 2SO3 → 2SO2 + O2; The tail gas is sent into the multi-stage absorption and conversion tower through the tail gas pipeline 9 after being dust-removed by the three-stage electrostatic precipitator 8. The sulfur dioxide gas, after being purified by the three-stage electrostatic precipitator 8, meets the reaction requirements. The conversion liquid and the absorption completion liquid after passing through the multi-stage absorption and conversion tower are sent into the evaporation equipment 22. The concentrated liquid output by the evaporation equipment 22 is processed by the cooling crystallization equipment 20 to form crystal slurry. There is a conveying pipeline 14 between the evaporation equipment 22 and the crystallization equipment 20 for cooling crystallization or evaporation crystallization. For cooling crystallization, the solution is generally cooled to 10-20 °C to precipitate ammonium sulfite crystals; for evaporation crystallization, under reduced pressure, the solution is heated to evaporate water to promote the crystallization of ammonium sulfite, and the crystallization time is generally 3-6 hours. The crystal slurry is separated by the separation equipment 24 to obtain ammonium nitrite. The cooling crystallization equipment 20 is connected to the separation equipment 24 through the crystal slurry pipeline 23. The crystallized mixed liquid is sent into a centrifuge for solid-liquid separation to obtain ammonium sulfite crystals. The solid output end of the separation equipment 21 is connected to the product pipeline 21.

[0017] In a preferred embodiment, the multi-stage absorption and conversion tower consists of a spray tower a10, a spray tower b16, a spray tower c18, a series pipeline 12 and an absorbent pipeline 17. The tail gas outlet of the spray tower a10 is connected to the tail gas inlet of the spray tower b16 through the series pipeline 12. The tail gas outlet of the spray tower b16 is connected to the tail gas inlet of the spray tower c18 through the series pipeline 12. The absorption liquid of the spray tower c18 is transported to the spray tower b16 through the absorbent pipeline 17. The absorption liquid of the spray tower b16 is transported to the spray tower a10 through the absorbent pipeline 17. The tail gas after dust removal treatment is sent into the multi-stage absorption and conversion tower through the tail gas pipeline 9. The spray tower a10, the spray tower b16 and the spray tower c18 are connected in series. Absorbents are sprayed in the spray tower a10, the spray tower b16 and the spray tower c18, and the tail gas is successively absorbed. The rear end of the spray tower c18 is connected to a tail gas treatment device and an exhaust device. The three spray towers continuously spray and wash. After the ammonium sulfite concentration in the spray tower a10 reaches 80 g / L, it is discharged to the evaporation equipment 22 for low-temperature evaporation. The absorption liquid in the spray tower b16 is pumped into the spray tower a10, the absorption liquid in the spray tower c18 is pumped into the spray tower b16, and a new absorbent is added to the spray tower c18 for reaction. The qualified liquid is discharged from the spray tower 1. After the qualified liquid is discharged, it enters a low-temperature evaporation crystallizer for evaporation crystallization. The produced pure water is used to prepare the absorbent. The solid product is dried and then packaged, which is the target product of this time.

[0018] In a preferred embodiment, the conversion liquid and the absorption completion liquid output by the spray tower a10 are sent into the evaporation equipment 22 through the completion liquid pipeline 15. The mother liquor output by the separation equipment 24 is sent into the evaporation equipment 22 through the mother liquor pipeline 19.

[0019] In a preferred embodiment, absorbent addition pipelines 13 are provided on spray tower a10, spray tower b16 and spray tower c18. Spray devices are arranged inside spray tower a10, spray tower b16 and spray tower c18. The absorbent and the absorption liquid are evenly sprayed inside the spray towers by spraying. The absorbent is ammonia water. 8 moles of ammonia water are added to spray tower a10, 6 moles of ammonia water are added to spray tower b16, and 4 moles of ammonia water are added to spray tower c18. The absorption liquid formed in spray tower c18 is sent to spray tower b16, and the absorption liquid formed in spray tower b16 is sent to spray tower a10.

[0020] In a preferred embodiment, the tail gas output end of spray tower c18 is communicated with the tail gas pipeline 9 by arranging a tail gas reflux pipeline 11 to recycle and convert the unabsorbed sulfur dioxide.

[0021] It should be noted that the above embodiments all belong to the same inventive concept. The descriptions of the embodiments have their own emphases. For the parts not described in detail in individual embodiments, reference can be made to the descriptions in other embodiments.

[0022] The above embodiments only express the implementation manners of the present invention. The descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the inventive concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A system for producing ammonium sulfite using an electrolytic manganese ammonium sulfate double salt, characterized in that, The invention comprises a drum high-temperature drying device (1), wherein the electrolytic manganese ammonium sulfate mixture outputted from the drum high-temperature drying device (1) is sent to a crushing device (6) via an elevator (4), and the electrolytic manganese ammonium sulfate mixture outputted from the crushing device (6) is sent to an oxygen-free calcining furnace (7), and the rear end of the oxygen-free calcining furnace (7) is connected to a three-stage electrostatic precipitator (8), and the tail gas is sent to a multi-stage absorption conversion tower via a tail gas pipeline (9) after being dedusted by the three-stage electrostatic precipitator (8), and the converted liquid and the absorbed liquid after passing through the multi-stage absorption conversion tower are sent to an evaporation device (22), and the concentrated liquid outputted from the evaporation device (22) is processed by a cooling crystallization device (20) to form a crystal slurry, and the crystal slurry is separated into ammonium nitrite by a separation device (24).

2. The system for producing ammonium sulfite using the electrolytic manganese ammonium sulfate double salt according to claim 1, characterized in that, The crushing device (6) is equipped with a filter device (5) to control the particle size of the crushed electrolytic manganese ammonium sulfate mixture to 50 meshes.

3. The system for producing ammonium sulfite using the electrolytic manganese ammonium sulfate double salt according to claim 1, characterized in that, The multi-stage absorption conversion tower comprises a spray tower a (10), a spray tower b (16), a spray tower c (18), a series pipeline (12) and an absorbent pipeline (17); the tail gas outlet of the spray tower a (10) is connected to the tail gas inlet of the spray tower b (16) through the series pipeline (12); the tail gas outlet of the spray tower b (16) is connected to the tail gas inlet of the spray tower c (18) through the series pipeline (12); the absorption liquid of the spray tower c (18) is transported to the spray tower b (16) through the absorbent pipeline (17); and the absorption liquid of the spray tower b (16) is transported to the spray tower a (10) through the absorbent pipeline (17).

4. The system for producing ammonium sulfite using ammonium sulfate complex salt of electrolytic manganese according to claim 3, characterized in that, The conversion liquid and absorption completion liquid outputted from the spray tower a (10) are sent to the evaporation device (22) through the completion liquid pipeline (15), and the mother liquid outputted from the separation device (24) is sent to the evaporation device (22) through the mother liquid pipeline (19).

5. A system for producing ammonium sulfite using the electrolytic manganese ammonium sulfate double salt according to claim 3, characterized in that, The spray tower a (10), the spray tower b (16) and the spray tower c (18) are all provided with an absorbent adding pipeline (13), and the spray tower a (10), the spray tower b (16) and the spray tower c (18) are provided with a spray device inside to spray the absorbent and the absorption liquid evenly into the inside of the spray tower.

6. The system for producing ammonium sulfite using the electrolytic manganese ammonium sulfate double salt according to claim 3, characterized in that, The tail gas output end of the spray tower c (18) is connected to the tail gas pipeline (9) by providing a tail gas reflux pipeline (11).

7. A system for producing ammonium sulfite using the electrolytic manganese ammonium sulfate double salt according to claim 6, characterized in that, The method for producing ammonium sulfite using the system comprises the following steps: S1: The electrolytic manganese ammonium sulfate mixture is placed in a drum high temperature drying device (1) to dry the water at 150°C; S2: The dried mixture of S1 is crushed and sieved to 50 meshes by a crushing device (6) so that the pyrolysis during oxygen-free calcination is uniform; S3: sending the sieved mixture in S2 into an oxygen-free calcining furnace (7) for oxygen-free calcining and decomposition; S4: the tail gas generated by the oxygen-free calcination in S3 is subjected to dust removal treatment by a three-stage electrostatic precipitator (8) connected to the rear end of the oxygen-free calcining furnace (7); S5: sending the exhaust gas after the dust removal treatment in S4 into a multi-stage absorption and conversion tower through an exhaust gas pipeline (9); S6: The spray towers a (10), b (16), and c (18) are connected in series. Absorbent is sprayed in the spray towers a (10), b (16), and c (18), and the tail gas is absorbed in sequence as it passes through. The rear end of the spray tower c (18) is connected to a tail gas treatment device and an evacuation device; S7: The three spray towers perform continuous spray washing. After the ammonium sulfite concentration in the spray tower a (10) reaches 80 g / L, it is discharged to the evaporation equipment (22) for low-temperature evaporation; S8: The absorbent liquid in the spray tower b (16) is pumped into the spray tower a (10), the absorbent liquid in the spray tower c (18) is pumped into the spray tower b (16), a new absorbent is added to the spray tower c (18) for reaction, and the qualified liquid is discharged from the spray tower a (10); S9: After the qualified liquid is discharged, it enters a low-temperature evaporation crystallizer for evaporation crystallization. The produced pure water is used to prepare the absorbent liquid, and the solid product is dried and then packaged, which is the target product of this time.

8. A method for producing ammonium sulfite using the electrolytic manganese ammonium sulfate double salt according to claim 7, characterized in that, The mixture is fed into an anaerobic calcination furnace (7) for anaerobic calcination and decomposition at 550 - 600 °C for 0.2 - 2 hours.

9. A method for producing ammonium sulfite using ammonium sulfate complex salt of electrolytic manganese according to claim 7, characterized in that, The absorbent is ammonia water. 8 moles of ammonia water are added to the spray tower a (10), 6 moles of ammonia water are added to the spray tower b (16), and 4 moles of ammonia water are added to the spray tower c (18).

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