Device for resourceful treatment of waste sulfuric acid, fluorosilicic acid and hydrofluoric acid

Abstract

A kind of waste sulfuric acid fluorosilicic acid hydrofluoric acid resource processing device, including potassium fluorosilicate reaction filtration unit, sulfuric acid concentration unit, sulfuric acid stripping unit, tail gas treatment unit, sealing water unit;Device uses the process route of reaction filtration+evaporation concentration+high-temperature stripping to process the waste acid, mature technology, stable operation, simple operation, reasonable operation cost, less comprehensive investment, harmful acid waste is converted into usable industrial raw materials, both solve the environmental problem, also realize resource circulation, also create economic benefits for enterprise, especially applicable to chemical industry, metallurgy, semiconductor and other " high acid consumption, high waste " industry.

Description

Technical Field

[0001] This utility model belongs to the field of industrial waste acid recycling and treatment technology, specifically involving a waste sulfuric acid, fluorosilicic acid, and hydrofluoric acid resource utilization treatment device. Background Technology

[0002] In industrial production processes such as photovoltaics, electronics, and chemicals, large quantities of complex mixed waste acids are generated. The main component is sulfuric acid (H₂SO₄), and it also contains fluorides such as fluorosilicic acid (H₂SiF₆) and hydrofluoric acid (HF). If these waste acids are discharged directly without treatment, they will cause serious and lasting pollution to water bodies, soil, and the ecological environment. Furthermore, the sulfuric acid and hydrofluoric acid contained in these waste acids are highly valuable industrial raw materials, and their direct disposal represents a huge waste of resources.

[0003] Sulfuric acid is hailed as the "blood" of industrial production, with extremely wide applications in chemical, metallurgical, and electronics manufacturing fields. Hydrofluoric acid, due to its specific reactivity with silicon-based materials and its unique function as a highly efficient fluorinating agent, has become a "key chemical" supporting high-end manufacturing industries such as semiconductors, photovoltaics, and fluorochemicals, holding an irreplaceable position. Therefore, the resource-based recycling and utilization of these mixed waste acids has both environmental and economic benefits.

[0004] Currently, there are some technical challenges and bottlenecks in the industry regarding the treatment of such fluorine- and silicon-containing waste acids:

[0005] Separation difficulties: Sulfuric acid, hydrofluoric acid, and fluorosilicic acid interact with each other in solution, forming a complex equilibrium system. In particular, fluorosilicic acid decomposes under heating conditions to generate highly corrosive HF and silicon tetrafluoride (SiF4) gas, making efficient and clean separation of the components extremely difficult.

[0006] Severe equipment corrosion: HF and HF produced by the decomposition of fluorosilicic acid are extremely corrosive to glass, ceramics and most metal materials, requiring very high-quality materials for the treatment equipment, resulting in huge investment and maintenance costs.

[0007] High energy consumption and low purity of recovered products: Traditional evaporation and concentration processes often suffer from low heat transfer efficiency and high energy consumption. During evaporation, fluorides are prone to crystallization and scaling, clogging pipes and equipment, affecting the stability and continuity of operation. At the same time, it leads to excessive fluorine impurities in the recovered sulfuric acid, making it unsuitable for direct reuse in high-end production processes with strict requirements on fluorine content.

[0008] Secondary pollution risk: If the treatment process is not perfect, toxic and harmful gases such as hydrogen fluoride and silicon tetrafluoride may be released during the process, posing safety and environmental hazards.

[0009] Existing treatment technologies, such as simple neutralization, are easy to operate but convert all valuable components into waste residue, failing to achieve resource recovery. Meanwhile, some preliminary recycling processes often suffer from problems such as long processes, high energy consumption, large equipment investment, and unstable quality of recycled products, making it difficult to meet the needs of large-scale, low-cost, and high-value industrial recycling.

[0010] Therefore, the industry urgently needs an integrated technology and device that can efficiently, stably, and economically separate and recycle sulfuric acid and fluoride, converting valuable components in waste acid into reusable industrial products while ensuring safety and environmental protection. Summary of the Invention

[0011] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a waste sulfuric acid, fluorosilicic acid and hydrofluoric acid resource utilization device that reduces environmental disposal pressure and environmental pollution risk.

[0012] The technical solution adopted to solve the above technical problems is: a waste sulfuric acid, fluorosilicate and hydrofluoric acid resource utilization treatment device, including a potassium fluorosilicate reaction and filtration unit, a sulfuric acid concentration unit, a sulfuric acid stripping unit, a tail gas treatment unit and a sealing water unit;

[0013] The potassium fluorosilicate reaction filtration unit is as follows: waste mixed acid in the mixed acid storage tank enters the first and second reaction vessels through a waste mixed acid feed pump installed on the pipeline. The bottom outlets of the first and second reaction vessels are connected to the first and second reaction vessels through a potassium fluorosilicate crystal slurry discharge pump installed on the pipeline, and the other is connected to the potassium fluorosilicate filter. The upper outlets of the first and second reaction vessels are connected to the inlet of the reaction cooler through a reaction cooling circulation pump installed on the pipeline. The outlet of the reaction cooler is connected to the first and second reaction vessels. The top outlet of the potassium fluorosilicate filter is connected to the first and second reaction vessels, the lower outlet is connected to the desiliconized fluorine-containing sulfuric acid tank, and the bottom outlet is connected to the potassium fluorosilicate packaging machine. The desiliconized fluorine-containing sulfuric acid tank is connected to the first and second reaction vessels through a desiliconized fluorine-containing sulfuric acid pump installed on the pipeline, and the other is connected to the sulfuric acid concentration unit.

[0014] The sulfuric acid concentration unit comprises: a desiliconized fluorinated sulfuric acid pump that pumps fluorinated sulfuric acid into a preheater; the outlet of the preheater is connected to a first-effect evaporator via a first-effect evaporation circulation pump installed on a pipeline; the top outlet of the first-effect evaporator is connected to a first-effect separator, and the bottom outlet is connected to a steam condensate tank; the bottom outlet of the first-effect separator is connected to the first-effect evaporator via a first-effect evaporation circulation pump installed on a pipeline, and another outlet is connected to the second-effect evaporator via a second-effect evaporation circulation pump installed on a pipeline; the top outlet of the first-effect separator is connected to the second-effect evaporator via a first saturator; the top outlet of the second-effect evaporator is connected to the second-effect separator; one outlet of the lower outlet of the second-effect evaporator is connected to the first-effect evaporation condensate tank, and the other outlet is connected to a hydrofluoric acid tank; the second-effect separator... The bottom outlet is connected to the second-effect evaporator via a double-effect evaporation circulation pump, and to the sulfuric acid stripping unit via a discharge pump installed in the second effect. The top of the second-effect separator is connected to the preheater, the first condenser, and the second condenser via a second saturator. The outlet of the preheater is connected to the first condenser and the second condenser. The middle outlet of the second condenser is connected to the first condenser. The lower outlets of the first and second condensers are connected to the third condenser via one path and to the hydrofluoric acid tank via another path. The lower outlet of the third condenser is connected to the hydrofluoric acid tank via one path and to the vacuum unit via another path. The hydrofluoric acid tank is connected to the hydrofluoric acid tank via a hydrofluoric acid pump installed on the pipeline, and to each saturator via a saturated water pump installed on the pipeline.

[0015] The sulfuric acid stripping unit is as follows: the concentrated material pumped by the double-effect discharge pump enters the deep stripping heater through the deep stripping concentration circulation pump. The top outlet of the deep stripping heater is connected to the middle of the deep stripping tower, and the bottom outlet is connected to the steam condensate tank. The bottom outlet of the steam condensate tank pumps the condensate back to the boiler through the steam condensate pump installed on the pipeline. The top outlet of the steam condensate tank is connected to the middle of the deep stripping tower. The bottom outlet of the deep stripping tower is connected to the deep stripping heater through the deep stripping concentration circulation pump. The bottom outlet of the deep stripping tower is connected to the upper part of the deep stripping tower and the sulfuric acid cooler through the fluorine stripping circulation pump. The top outlet of the deep stripping tower is connected to the preheater, the first condenser, the second condenser, and the third condenser through the third saturator.

[0016] The exhaust gas treatment unit consists of: a first reaction vessel, a second reaction vessel, a desiliconized and fluorinated sulfuric acid tank, a potassium fluorosilicate packaging machine, a vacuum unit, a potassium hydroxide solution preparation tank, and a potassium fluorosilicate filter. The non-condensable gas discharged from the filter enters the primary absorption tower. The lower outlet of the primary absorption tower is connected to the primary absorption cooler via a primary absorption circulation pump, and the top outlet is connected to the secondary and tertiary absorption towers. The primary absorption cooler is connected to the primary absorption tower. The potassium hydroxide solution preparation tank is connected to the secondary absorption tower via a potassium hydroxide solution pump installed on a pipeline, with one connection to the secondary absorption tower and the other connection to the tertiary absorption tower. The lower outlet of the secondary absorption tower is connected to the secondary absorption tower via a secondary absorption circulation pump installed on a pipeline, and the top outlet is connected to the tertiary absorption tower. The lower part of the tertiary absorption tower is connected to the tertiary absorption tower via a tertiary absorption circulation pump installed on a pipeline, and the top outlet is connected to the exhaust gas induced draft fan. The exhaust gas induced draft fan discharges the exhaust gas.

[0017] The aforementioned sealing water unit: the return water from each pump enters the sealing water tank, and the sealing water tank discharges the sealing water to the sewage treatment plant through one sealing water pump and to the sealing water inlet of each pump through another sealing water pump.

[0018] The outlet of the reaction cooler of this utility model is connected to the static mixer, the outlet of the static mixer is connected to the refrigerant tank, one outlet of the refrigerant tank is connected to the reaction cooler through a refrigerant circulation pump installed on the pipeline, and the other outlet is connected to the refrigeration unit through a refrigerant pump installed on the pipeline. The outlet of the refrigeration unit is connected to the static mixer, and the refrigeration unit is supplied with cooling water by a cooling tower pool through a cooling circulation water pump.

[0019] The first and second reaction vessels of this invention are supplied with compressed air by an air compressor.

[0020] The deep stripping tower of this invention uses compressed air heated by a compressed air heater.

[0021] This utility model comprises a first reaction vessel, a second reaction vessel, a desiliconized and fluorine-containing sulfuric acid tank, a first-effect separator, a second-effect separator, a vacuum unit, a primary absorption tower, a potassium hydroxide solution preparation tank, a secondary absorption tower, a tertiary absorption tower, a deep stripping tower, a sealed water tank, and a cooling water tower pool for supplying process water.

[0022] The deep stripping heater, single-effect evaporator, and deep stripping tower of this invention are heated by external generated steam.

[0023] The sulfuric acid cooler, vacuum unit, sealed water tank, primary absorption cooler, and third condenser of this utility model are supplied with cooling water by a cooling water tower pool through a cooling circulating water pump; the outlet of the first condenser is connected to the cooling water tower pool, and the cooling water tower pool is connected to the second condenser through a cooling circulating water pump installed on a pipeline.

[0024] This invention has the following advantages over the prior art:

[0025] 1. To remove fluorosilicic acid from the waste acid in this device, the low solubility of potassium fluorosilicate in sulfuric acid is utilized. Potassium sulfate is added to react with the fluorosilicic acid in the waste acid, and potassium fluorosilicate is produced after filtration.

[0026] 2. The evaporation and concentration system of this device adopts double-effect evaporation and concentration, which increases the total heat transfer temperature difference and the heat utilization rate. The evaporation and concentration material flow adopts the co-current feeding method for evaporation and concentration operation, which conforms to the physical properties and has low heat loss. The evaporator adopts forced circulation evaporation, and the material flow velocity in the heat exchange tube is high, which vigorously scours the tube wall, enhances heat transfer and reduces the tendency of material scaling.

[0027] 3. This device is equipped with secondary steam to preheat the system feed, making comprehensive use of heat and saving energy and reducing consumption. Due to the increased material concentration, the boiling point rises, so the secondary steam is all superheated steam (superheated steam has a low heat transfer coefficient). A secondary steam saturator is installed to increase the heat transfer coefficient of the steam.

[0028] 4. The high-temperature stripping system of this device adopts a process that combines evaporation concentration and stripping. It uses the secondary steam generated by evaporation for stripping, which has high heat utilization and thorough stripping. It can also use high-temperature compressed air or air for stripping, which is more energy-efficient when the output and stripping requirements are not high. The fluorine stripping has multiple operating modes to meet the usage requirements of different working conditions.

[0029] 5. The exhaust gas (HF) of this device has a high concentration. The first stage uses water washing to recover hydrofluoric acid, and the second and third stages use potassium hydroxide countercurrent washing to ensure better exhaust gas treatment effect. All washing liquids are recycled and reused to achieve true zero emissions. Attached Figure Description

[0030] Figures 1-3 This is a structural schematic diagram of one embodiment of the present invention.

[0031] In the diagram: 1. Mixed acid storage tank; 2. Waste mixed acid feed pump; 3. First reaction vessel; 4. Reaction cooler; 5. Reaction cooling circulation pump; 6. Second reaction vessel; 7. Potassium fluorosilicate crystal slurry discharge pump; 8. Desiliconized fluorine-containing sulfuric acid pump; 9. Desiliconized fluorine-containing sulfuric acid tank; 10. Potassium fluorosilicate packaging machine; 11. Sulfuric acid cooler; 12. Fluorine stripping circulation pump; 13. Deep stripping and concentration circulation pump; 14. Deep stripping heater; 15. Steam condensate pump; 16. Steam condensate tank; 17. First-effect evaporator; 18. First-effect evaporation circulation pump; 19. First-effect separator; 20. First-effect evaporation condensate pump; 21. First-effect evaporation condensate tank; 22. Second-effect discharge pump; 23. Second-effect evaporator; 24. Second-effect evaporation circulation pump; 25. Second-effect separator; 26. Hydrofluoric acid tank; 27. Hydrofluoric acid pump; 28. Saturated water pump; 29. 30. Vacuum unit; 31. First-stage absorption tower; 32. First-stage absorption circulation pump; 33. Potassium hydroxide solution preparation tank; 34. Potassium hydroxide solution pump; 35. Second-stage absorption tower; 36. Second-stage absorption circulation pump; 37. Tertiary absorption tower; 38. Tertiary absorption circulation pump; 39. Exhaust gas induced draft fan; 40. Sealed water tank; 41. Sealed water pump; 42. Refrigerant circulation pump; 43. Refrigerant tank; 44. Static mixer; 45. Refrigerant pump; 46. Refrigeration unit; 47. Circulating water pump; 48. Cooling tower pool; 49. First-stage absorption cooler; 50. Third-stage condenser; 51. Second-stage condenser; 52. Preheater; 53. Third-stage saturator; 54. Second-stage saturator; 55. First-stage saturator; 56. Deep stripping tower; 57. Compressed air heater; 58. Potassium fluorosilicate filter. Detailed Implementation

[0032] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments, but the present invention is not limited to these embodiments.

[0033] Example 1

[0034] exist Figures 1-3 The present invention relates to a waste sulfuric acid, fluorosilicate, and hydrofluoric acid resource utilization treatment device, which includes a potassium fluorosilicate reaction and filtration unit, a sulfuric acid concentration unit, a sulfuric acid stripping unit, a tail gas treatment unit, and a sealing water unit.

[0035] The potassium fluorosilicate reaction filtration unit is as follows: waste mixed acid in the mixed acid storage tank 1 enters the first reaction vessel 3 and the second reaction vessel 6 through the waste mixed acid feed pump 2 installed on the pipeline. The bottom outlets of the first reaction vessel 3 and the second reaction vessel 6 are connected to the first reaction vessel 3 and the second reaction vessel 6 through the potassium fluorosilicate crystal slurry discharge pump 7 installed on the pipeline, and are also connected to the potassium fluorosilicate filter 58. The upper outlets of the first reaction vessel 3 and the second reaction vessel 6 are connected to the inlet of the reaction cooler 4 through the reaction cooling circulation pump 5 installed on the pipeline. The outlet of the reaction cooler 4 is connected to the first reaction vessel 3 and the second reaction vessel 6. The top outlet of the potassium fluorosilicate filter 58 is connected to the first reaction vessel 3 and the second reaction vessel 6, the lower outlet is connected to the desiliconized fluorinated sulfuric acid tank 9, and the bottom outlet is connected to the potassium fluorosilicate packaging machine 10. The desiliconized fluorinated sulfuric acid tank 9 is connected to the first reaction vessel 3 and the second reaction vessel 6 through the desiliconized fluorinated sulfuric acid pump 8 installed on the pipeline, and is also connected to the sulfuric acid concentration unit.

[0036] The sulfuric acid concentration unit comprises: a desiliconized fluorinated sulfuric acid pump 8 pumps fluorinated sulfuric acid into a preheater 52; the outlet of the preheater 52 is connected to a first-effect evaporator 17 via a first-effect evaporation circulation pump 18 installed on a pipeline; the top outlet of the first-effect evaporator 17 is connected to a first-effect separator 19, and the bottom outlet is connected to a steam condensate tank 16; the bottom outlet of the first-effect separator 19 is connected to the first-effect evaporator 17 via the first-effect evaporation circulation pump 18 installed on a pipeline, and another outlet is connected to a second-effect evaporator 23 via a second-effect evaporation circulation pump 24 installed on a pipeline; the top outlet of the first-effect separator 19 is connected to the second-effect evaporator 23 via a first saturator 55; the top outlet of the second-effect evaporator 23 is connected to a second-effect separator 25; the bottom outlet of the second-effect evaporator 23 is connected to a first-effect evaporation condensate tank 21 on one side and a hydrofluoric acid tank 26 on the other side; and the second-effect separator 25... The bottom outlet is connected to the second-effect evaporator 23 via the second-effect evaporation circulation pump 24, and to the sulfuric acid stripping unit via the second-effect discharge pump 22. The top of the second-effect separator 25 is connected to the preheater 52, the first condenser 51, and the second condenser 50 via the second saturator 54. The outlet of the preheater 52 is connected to the first condenser 51 and the second condenser 50. The middle outlet of the second condenser 50 is connected to the first condenser 51. The lower outlets of the first condenser 51 and the second condenser 50 are connected to the third condenser 49 via one path and to the hydrofluoric acid tank 26 via the other path. The lower outlet of the third condenser 49 is connected to the hydrofluoric acid tank 26 via one path and to the vacuum unit 29 via the other path. The hydrofluoric acid tank 26 is connected to the hydrofluoric acid tank via the hydrofluoric acid pump 27 installed on the pipeline, and to each saturator via the saturation water pump 28 installed on the pipeline.

[0037] The sulfuric acid stripping unit is as follows: the concentrated material pumped by the double-effect discharge pump 22 enters the deep stripping heater 14 through the deep stripping concentration circulation pump 13. The top outlet of the deep stripping heater 14 is connected to the middle of the deep stripping tower 56, and the bottom outlet is connected to the steam condensate tank 16. The bottom outlet of the steam condensate tank 16 pumps the condensate back to the boiler through the steam condensate pump 15 installed on the pipeline. The top outlet is connected to the middle of the deep stripping tower 56. The bottom outlet of the deep stripping tower 56 is connected to the deep stripping heater 14 through the deep stripping concentration circulation pump 13. The bottom outlet of the deep stripping tower 56 is connected to the upper part of the deep stripping tower 56 through the fluorine stripping circulation pump 12, and the other part is connected to the sulfuric acid cooler 11. The top outlet of the deep stripping tower 56 is connected to the preheater 52, the first condenser 51, the second condenser 50, and the third condenser 49 through the third saturator 53.

[0038] The exhaust gas treatment unit comprises: a first reaction vessel 3, a second reaction vessel 6, a silicon-removing and fluorine-containing sulfuric acid tank 9, a potassium fluorosilicate packaging machine 10, a vacuum unit 29, a potassium hydroxide solution preparation tank 32, and a potassium fluorosilicate filter 58. The non-condensable gas discharged from the filter enters the primary absorption tower 30. The lower outlet of the primary absorption tower 30 is connected to the primary absorption cooler 48 via a primary absorption circulation pump 31, and the top outlet is connected to the secondary absorption tower 34 and the tertiary absorption tower 36. The primary absorption cooler 48 is connected to the primary absorption tower 30. The potassium hydroxide solution... The preparation tank 32 is connected to the secondary absorption tower 34 via a potassium hydroxide solution pump 33 installed on the pipeline, and to the tertiary absorption tower 36 via another pipeline. The lower outlet of the secondary absorption tower 34 is connected to the secondary absorption tower 34 via a secondary absorption circulation pump 35 installed on the pipeline, and the top outlet is connected to the tertiary absorption tower 36. The lower part of the tertiary absorption tower 36 is connected to the tertiary absorption tower 36 via a tertiary absorption circulation pump 37 installed on the pipeline, and the top outlet is connected to the exhaust gas induced draft fan 39. The exhaust gas induced draft fan 39 discharges the exhaust gas.

[0039] The sealing water unit: the return water from each pump enters the sealing water tank 39, and the sealing water tank 39 discharges the sealing water to the sewage treatment plant through the sealing water pump 40 in one way and to the sealing water inlet of each pump in another way.

[0040] In this embodiment, the outlet of the reaction cooler 4 is connected to the static mixer 43, and the outlet of the static mixer 43 is connected to the chilled liquid tank 42. One outlet of the chilled liquid tank 42 is connected to the reaction cooler 4 via a chilled liquid circulation pump 41 installed on a pipeline, and the other outlet is connected to the chiller unit 45 via a chilled liquid pump 44 installed on a pipeline. The outlet of the chiller unit 45 is connected to the static mixer 43. The chiller unit 45 is supplied with cooling water by a cooling water tower pool 47 via a cooling water circulation pump 46. The first reaction vessel 3 and the second reaction vessel 6 are supplied with compressed air by an air compressor. The deep stripping tower 56 is heated by a compressed air heater 57. The first reaction vessel 3, the second reaction vessel 6, the desiliconized fluorine-containing sulfuric acid tank 9, the first-effect separator 19, the second-effect separator 25, the vacuum unit 29, the first-stage absorption tower 30, the potassium hydroxide solution preparation tank 32, the second-stage absorption tower 34, the third-stage absorption tower 36, the deep stripping tower 56, the sealed water tank 39, and the cooling water tower pool 47 are supplied with process water. The deep desulfurization heater 14, the first-effect evaporator 17, and the deep desulfurization stripping tower 56 are heated by external live steam. The sulfuric acid cooler 11, the vacuum unit 29, the sealed water tank 39, the first-stage absorption cooler 48, and the third condenser 49 are supplied with cooling water from the cooling water tank 47 via the cooling water circulation pump 46; the outlet of the first condenser 51 is connected to the cooling water tank 47, and the cooling water tank 47 is connected to the second condenser 50 via the cooling water circulation pump 46 installed on the pipeline.

[0041] The working principle of this utility model is as follows:

[0042] 1) Material flow:

[0043] a. Reaction and Filtration Material Flow

[0044] Waste mixed acid from outside is first added to the first reactor 3 and the second reactor 6, followed by potassium sulfate. The materials in the reactors react fully under the action of a stirrer to generate a potassium fluorosilicate solution. Then, the material is pumped by the reaction cooling circulation pump 5 to the reaction cooler 4 for circulating cooling. The cooled material is then returned to the first reactor 3 and the second reactor 6. Next, the potassium fluorosilicate slurry discharge pump 7 pumps it to the potassium fluorosilicate filter buffer tank, and then into the potassium fluorosilicate filter 58 to filter out potassium fluorosilicate crystals, which are then packaged and shipped. The mother liquor from the potassium fluorosilicate filter 58 flows to the silicon-removing fluorine-containing sulfuric acid tank 9, and finally, it is pumped by the silicon-removing fluorine-containing sulfuric acid pump 8 to the evaporation and concentration system for the next step of evaporation and concentration treatment.

[0045] b. Evaporation and Concentration Material Process

[0046] Fluorine-containing sulfuric acid (hereinafter referred to as material) filtered from the reaction filtration system is first pumped into the preheater 52 by the silicon-removing fluorine-containing sulfuric acid pump 8. It is preheated by the heat of the secondary steam from the double-effect separator 25. After preheating, it enters the first-effect evaporator group.

[0047] The material in the first-effect evaporator group is heated and circulated in the first-effect evaporator 17 by the first-effect evaporation circulation pump 18. After being heated, the material undergoes vapor-liquid separation in the first-effect separator 19. The preliminarily concentrated material is pumped to the second-effect evaporator group by the first-effect evaporation circulation pump 18.

[0048] The material in the double-effect evaporator group is heated and circulated in the double-effect evaporator 23 by the double-effect evaporation circulation pump 24. After being heated, the material undergoes vapor-liquid separation in the double-effect separator 25. Finally, the concentrated material is pumped to the high-temperature stripping system for further processing by the double-effect discharge pump 22.

[0049] The liquid level of each separator is automatically adjusted to control the feed and discharge, thereby achieving automatic and continuous feeding and discharging of materials, and ensuring that the evaporation system is in a high-efficiency and stable evaporation state.

[0050] c. High-temperature stripping system process

[0051] The concentrated material from the evaporation and concentration system first enters the deep stripping tower 56. Then, the material is heated in the deep stripping heater 14 by the deep stripping and concentration circulation pump 13. After heating, the material undergoes vapor-liquid separation in the lower part of the deep stripping tower 56. The concentrated material is then pumped to the upper part of the deep stripping tower 56 by the fluorine stripping circulation pump 12. The material is then stripped by the secondary steam separated from the evaporation and concentration in the lower part. Finally, the material is diverted to the sulfuric acid cooler 11 by the fluorine stripping circulation pump 12 and cooled by circulating cooling water before being pumped out for storage.

[0052] The high-temperature stripping system can also be used to strip using high-temperature compressed air or air. It can be used when the output and stripping requirements are not high. There are multiple operating modes for fluorine stripping to meet the requirements of different working conditions.

[0053] The liquid level in the deep stripping tower 56 is automatically adjusted to control the feed and discharge, thereby achieving automatic and continuous feeding and discharging of materials and ensuring that the evaporation system is in a high-efficiency and stable evaporation state.

[0054] 2) Steam heating process:

[0055] a. Evaporation and Concentration Steam Process

[0056] The raw steam from the outside first enters the material in the shell side of the first-effect evaporator 17 and the heating tube side. The heated material undergoes flash evaporation and vapor-liquid separation in the first-effect separator 19. The generated secondary steam is sprayed through the first saturator 55 and then enters the material in the shell side of the second-effect evaporator 23 and the heating tube side. The heated material undergoes flash evaporation and vapor-liquid separation in the second-effect separator 25. The generated secondary steam is sprayed through the second saturator 54 and then mostly enters the tube side of the first, second, and third condensers to be condensed. A small portion enters the shell side of the preheater 52 to preheat the feed of the evaporation and concentration system.

[0057] b. High-temperature deep steam removal process

[0058] The raw steam from the outside first enters the shell side of the deep descaling heater 14 to heat the material in the tube side. The heated material undergoes flash evaporation in the lower part of the deep descaling stripping tower 56 for vapor-liquid separation. The generated secondary steam strips the fluorine from the material in the system. After completion, it is sprayed through the third saturator 53 and then enters the tube side of the first, second and third condensers to be condensed.

[0059] 3) Steam condensate flow:

[0060] 3.1 Evaporation and Concentration System

[0061] a. Steam condensate flow:

[0062] The steam condensate from the shell side of the first-effect evaporator 17 flows into the steam condensate tank 16 by pressure difference, and is finally pumped out or reused by the steam condensate pump 15.

[0063] b. Evaporation and condensate water process:

[0064] The evaporation condensate (separately recovered) in the shell side of the second-effect evaporator 17 flows to the first-effect evaporation condensate tank 21 by pressure difference, and is finally pumped out or reused by the first-effect evaporation condensate pump 22.

[0065] The condensate from the first, second, and third condenser tube sides flows to the hydrofluoric acid tank 26 by pressure difference, and is finally pumped out for reuse by the hydrofluoric acid pump 27. A small portion of the condensate is pumped to each saturator by the saturation water pump 28 to spray superheated secondary steam.

[0066] 3.2 High-Temperature Deep Desorption System

[0067] a. Steam condensate flow:

[0068] The steam condensate from the shell side of the deep desorption heater 14 also flows to the steam condensate tank 16 by pressure difference, and is finally pumped out or reused by the steam condensate pump 15.

[0069] b. Evaporation and condensate water process:

[0070] The condensate from the ABC tube side of the condenser flows to the hydrofluoric acid tank by pressure difference, and is finally pumped out for reuse by the hydrofluoric acid pump. A small portion of the condensate is pumped to each saturator by a saturation water pump to spray superheated secondary steam.

[0071] 4) Non-condensable gas system process:

[0072] a. Non-condensable gas flow in evaporation-condensation system

[0073] The vacuum system consists of first, second, and third condensers, and vacuum unit 29. Secondary steam generated in the double-effect separator 25 enters the tube side of the condenser for condensation. The resulting condensate flows into the hydrofluoric acid tank 26. Non-condensable gases (steam, air, or other non-condensable gases) exiting the third condenser 49 are extracted by vacuum unit 29, undergo gas-liquid separation in the water tank of vacuum unit 29, and are then discharged into the tail gas collection pipeline. Simultaneously, the vacuum pump maintains the required vacuum level for the entire evaporation crystallization system.

[0074] b. Non-condensable gas process in high-temperature deep degassing system

[0075] The vacuum system consists of first, second, and third condensers, and vacuum unit 29. Secondary steam generated in the deep stripping tower 56 enters the tube side of the condenser for condensation. The resulting condensate flows into the hydrofluoric acid tank 26. Non-condensable gases (steam, air, or other non-condensable gases) exiting condenser C are extracted by vacuum unit 29, undergo gas-liquid separation in the water tank of vacuum unit 29, and are then discharged into the tail gas collection pipeline. Simultaneously, the vacuum pump maintains the required vacuum level for the entire evaporation crystallization system.

Claims

1. A resource recovery device for waste sulfuric acid, fluorosilicate, and hydrofluoric acid, characterized in that: It includes a potassium fluorosilicate reaction filtration unit, a sulfuric acid concentration unit, a sulfuric acid stripping unit, a tail gas treatment unit, and a sealing water unit; The potassium fluorosilicate reaction filtration unit is as follows: waste mixed acid in the mixed acid storage tank (1) enters the first reaction vessel (3) and the second reaction vessel (6) through the waste mixed acid feed pump (2) installed on the pipeline. The bottom outlets of the first reaction vessel (3) and the second reaction vessel (6) are connected to the first reaction vessel (3) and the second reaction vessel (6) through the potassium fluorosilicate crystal slurry discharge pump (7) installed on the pipeline, and the other path is connected to the potassium fluorosilicate filter (58). The upper outlets of the first reaction vessel (3) and the second reaction vessel (6) are connected to the reaction cooling circulation pump (5) installed on the pipeline. The inlet of the reaction cooler (4) is connected to the outlet of the reaction cooler (4) and the first reaction vessel (3) and the second reaction vessel (6). The top outlet of the potassium fluorosilicate filter (58) is connected to the first reaction vessel (3) and the second reaction vessel (6), the bottom outlet is connected to the desiliconized fluorine-containing sulfuric acid tank (9), and the bottom outlet is connected to the potassium fluorosilicate packaging machine (10). The desiliconized fluorine-containing sulfuric acid tank (9) is connected to the first reaction vessel (3) and the second reaction vessel (6) through the desiliconized fluorine-containing sulfuric acid pump (8) installed on the pipeline, and is connected to the sulfuric acid concentration unit in another way. The sulfuric acid concentration unit is as follows: a desiliconized fluorinated sulfuric acid pump (8) pumps fluorinated sulfuric acid into a preheater (52). The outlet of the preheater (52) is connected to a first-effect evaporator (17) via a first-effect evaporation circulation pump (18) installed on a pipeline. The top outlet of the first-effect evaporator (17) is connected to a first-effect separator (19), and the bottom outlet is connected to a steam condensate tank (16). The bottom outlet of the first-effect separator (19) is connected to the first-effect evaporator (16) via a first-effect evaporation circulation pump (18) installed on a pipeline. 7) One path is connected to the second-effect evaporator (23) via a second-effect evaporation circulation pump (24) installed on the pipeline. The top outlet of the first-effect separator (19) is connected to the second-effect evaporator (23) via the first saturator (55). The top outlet of the second-effect evaporator (23) is connected to the second-effect separator (25). One path of the lower outlet of the second-effect evaporator (23) is connected to the first-effect evaporation condensate tank (21), and the other path is connected to the hydrofluoric acid tank (26). The bottom of the second-effect separator (25) The outlet is connected to the second-effect evaporator (23) via a double-effect evaporation circulation pump (24) on one side and to the sulfuric acid stripping unit via a second-effect discharge pump (22) on the other side; the top of the second-effect separator (25) is connected to the preheater (52), the first condenser (51), and the second condenser (50) via a second saturator (54); the outlet of the preheater (52) is connected to the first condenser (51) and the second condenser (50); the middle outlet of the second condenser (50) is connected to the first condenser (51) and the second condenser (50). 1) Connected, the lower outlets of the first condenser (51) and the second condenser (50) are connected to the third condenser (49) in one way and to the hydrofluoric acid tank (26) in the other way. The lower outlet of the third condenser (49) is connected to the hydrofluoric acid tank (26) in one way and to the vacuum unit (29) in the other way. The hydrofluoric acid tank (26) is connected to the hydrofluoric acid tank in one way through the hydrofluoric acid pump (27) installed on the pipeline, and to each saturator in the other way through the saturated water pump (28) installed on the pipeline. The sulfuric acid stripping unit is as follows: the concentrated material pumped by the double-effect discharge pump (22) enters the deep stripping heater (14) through the deep stripping concentration circulation pump (13). The top outlet of the deep stripping heater (14) is connected to the middle of the deep stripping tower (56), and the bottom outlet is connected to the steam condensate tank (16). The bottom outlet of the steam condensate tank (16) pumps the condensate back to the boiler through the steam condensate pump (15) installed on the pipeline. The top outlet is connected to the middle of the deep stripping tower (56). The bottom outlet of the stripping tower (56) is connected to the deep stripping heater (14) via the deep stripping concentration circulation pump (13). The bottom outlet of the deep stripping tower (56) is connected to the upper part of the deep stripping tower (56) via one fluorine stripping circulation pump (12) and to the sulfuric acid cooler (11) via the other. The top outlet of the deep stripping tower (56) is connected to the preheater (52), the first condenser (51), the second condenser (50), and the third condenser (49) via the third saturator (53). The exhaust gas treatment unit consists of: a first reaction vessel (3), a second reaction vessel (6), a silicon-removing fluorine-containing sulfuric acid tank (9), a potassium fluorosilicate packaging machine (10), a vacuum unit (29), a potassium hydroxide solution preparation tank (32), and a potassium fluorosilicate filter (58). The non-condensable gas discharged from the first-stage absorption tower (30) enters the first-stage absorption tower (30). The lower outlet of the first-stage absorption tower (30) is connected to the first-stage absorption cooler (48) through the first-stage absorption circulation pump (31), and the top outlet is connected to the second-stage absorption tower (34) and the third-stage absorption tower (36). The first-stage absorption cooler (48) is connected to the first-stage absorption tower (30). The potassium solution preparation tank (32) is connected to the secondary absorption tower (34) via a potassium hydroxide solution pump (33) installed on the pipeline, and to the tertiary absorption tower (36) via another pipeline. The lower outlet of the secondary absorption tower (34) is connected to the secondary absorption tower (34) via a secondary absorption circulation pump (35) installed on the pipeline, and the top outlet is connected to the tertiary absorption tower (36). The lower part of the tertiary absorption tower (36) is connected to the tertiary absorption tower (36) via a tertiary absorption circulation pump (37) installed on the pipeline, and the top outlet is connected to the exhaust gas induced draft fan (38). The exhaust gas induced draft fan (38) discharges the exhaust gas. The sealing water unit: the return water from each pump enters the sealing water tank (39), and the sealing water tank (39) discharges the sealing water to the sewage treatment station through the sealing water pump (40) in one way and to the sealing water inlet of each pump in another way.

2. The waste sulfuric acid, fluorosilicate, and hydrofluoric acid resource utilization treatment device according to claim 1, characterized in that: The outlet of the reaction cooler (4) is connected to the static mixer (43), the outlet of the static mixer (43) is connected to the refrigerant tank (42), one outlet of the refrigerant tank (42) is connected to the reaction cooler (4) through the refrigerant circulation pump (41) installed on the pipeline, and the other outlet is connected to the refrigeration unit (45) through the refrigerant pump (44) installed on the pipeline. The outlet of the refrigeration unit (45) is connected to the static mixer (43), and the refrigeration unit (45) is supplied with cooling water by the cooling tower pool (47) through the cooling circulation water pump (46).

3. The waste sulfuric acid, fluorosilicate, and hydrofluoric acid resource utilization treatment device according to claim 1, characterized in that: The first reactor (3) and the second reactor (6) are supplied with compressed air by an air compressor.

4. The waste sulfuric acid, fluorosilicate, and hydrofluoric acid resource utilization treatment device according to claim 1, characterized in that: The deep stripping tower (56) is heated by compressed air heated by a compressed air heater (57).

5. The waste sulfuric acid, fluorosilicate, and hydrofluoric acid resource utilization treatment device according to claim 1, characterized in that: The first reactor (3), the second reactor (6), the desiliconized fluorine-containing sulfuric acid tank (9), the first-effect separator (19), the second-effect separator (25), the vacuum unit (29), the first-stage absorption tower (30), the potassium hydroxide solution preparation tank (32), the second-stage absorption tower (34), the third-stage absorption tower (36), the deep stripping tower (56), the sealed water tank (39), and the cooling water tower pool (47) supply process water.

6. The waste sulfuric acid, fluorosilicate, and hydrofluoric acid resource utilization treatment device according to claim 1, characterized in that: The deep stripping heater (14), the first-effect evaporator (17), and the deep stripping tower (56) are heated by external live steam.

7. The waste sulfuric acid, fluorosilicate, and hydrofluoric acid resource utilization treatment device according to claim 1, characterized in that: The sulfuric acid cooler (11), vacuum unit (29), sealed water tank (39), primary absorption cooler (48), and third condenser (49) are supplied with cooling water by cooling water tank (47) through cooling water circulation pump (46); the outlet of the first condenser (51) is connected to the cooling water tank (47), and the cooling water tank (47) is connected to the second condenser (50) through cooling water circulation pump (46) installed on the pipeline.

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