Waste hydrochloric acid concentration distillation extraction apparatus

Abstract

A waste hydrochloric acid concentration distillation extraction device, including evaporation concentration unit, distillation extraction unit, tail gas treatment unit, sealing water unit, the device uses evaporation concentration + distillation extraction combination, using evaporator group will waste hydrochloric acid preliminary concentration to 18%, then using distillation extraction method, the concentration of hydrochloric acid is raised to 30%, reaches the industrial reuse standard, realizes the cyclic reuse of waste hydrochloric acid, the lower concentration waste hydrochloric acid is purified by concentration, distillation, extraction and other processes, and the hydrochloric acid can be reused in production, which reduces the purchase amount of new hydrochloric acid for enterprises, directly reduces the cost of raw materials, and is especially suitable for steel, electroplating, chemical and other industries with huge consumption of hydrochloric acid.

Description

Technical Field

[0001] This utility model belongs to the field of industrial wastewater treatment technology, specifically relating to a waste hydrochloric acid concentration, distillation and extraction device. Background Technology

[0002] Industrial processes such as metal pickling, electroplating, and chemical synthesis generate large quantities of complex waste hydrochloric acid. This waste liquid not only has a high acid concentration but also contains various metal ions such as iron, zinc, and nickel. Direct discharge would cause serious environmental pollution and waste valuable hydrochloric acid resources. With increasingly stringent environmental protection requirements and growing demands for resource recycling, efficient and economical recycling of waste hydrochloric acid has become an essential requirement for the sustainable development of related industries.

[0003] Before the development of concentration and recovery technologies, companies primarily used neutralization to treat waste hydrochloric acid. This method involves adding an alkali to neutralize the acid to a neutral state, with the resulting salt solution then undergoing further treatment or being discharged. While simple to operate, this method completely wastes the valuable components of the waste acid, incurs high treatment costs, and generates large amounts of saline sludge, failing to fundamentally solve the problems of resource waste and secondary pollution.

[0004] To recover hydrochloric acid, the industry has developed various processing technologies, but all of them have significant limitations:

[0005] Electrodialysis: This method is susceptible to impurities such as metal ions in waste acid, which can lead to blockage and contamination of the ion exchange membrane, resulting in poor system stability. Furthermore, the concentration of hydrochloric acid after concentration can usually only reach about 10%, limiting its recovery value.

[0006] Traditional distillation method: Due to the fact that hydrochloric acid and water form an azeotropic mixture, the concentration of hydrochloric acid that can be obtained by conventional distillation is difficult to exceed 18%, which cannot meet the concentration requirements for industrial reuse.

[0007] Extraction method: Using organic solvents such as amines as extractants can purify and concentrate hydrochloric acid, but the extractants themselves are expensive, and the subsequent regeneration process is energy-intensive and complex, with the risk of extractant loss and secondary pollution.

[0008] While existing technologies employ sulfuric acid as a dehydrating agent for auxiliary distillation, which can break the azeotropic equilibrium and obtain higher concentrations of hydrochloric acid, this technology typically suffers from several drawbacks, including fragmented process flows, low equipment integration, low utilization of the extractant (sulfuric acid), and high overall system energy consumption. The lack of effective coordination between unit operations results in large equipment footprints, failure to utilize heat energy in a cascaded manner, and persistently high operating and maintenance costs.

[0009] In summary, existing waste hydrochloric acid treatment technologies have significant shortcomings in terms of efficiency, economics, and the quality of recovered products. Therefore, the industry urgently needs to develop an integrated, high-efficiency, low-energy-consumption device capable of collaboratively addressing key issues such as metal impurity removal, azeotropic breakthrough, efficient concentration, and extractant recycling, thereby achieving a technological breakthrough in the resource recovery of waste hydrochloric acid. Summary of the Invention

[0010] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a waste hydrochloric acid concentration, distillation and extraction device that has low energy consumption, realizes the resource recovery and environmental compliance of waste hydrochloric acid, and reduces the enterprise's processing costs.

[0011] The technical solution adopted to solve the above technical problems is: a waste hydrochloric acid concentration, distillation and extraction device, including an evaporation and concentration unit, a distillation and extraction unit, a tail gas treatment unit, and a sealing water unit;

[0012] The evaporation and concentration unit is as follows: hydrochloric acid from the waste hydrochloric acid storage tank sequentially enters a primary preheater, a secondary preheater, and a tertiary preheater. One outlet of the tertiary preheater is connected to a first-effect separator, and the other outlet is connected to the secondary preheater. The bottom outlet of the first-effect separator is connected to the first-effect evaporator via a first-effect circulation pump installed on a pipeline, and the top outlet is connected to the second-effect evaporator. One outlet of the first-effect evaporator is connected to the secondary preheater, and the other outlet is connected to the first-effect separator. The outlet of the secondary preheater is connected to a steam condensate tank, which is connected to a boiler via a steam condensate pump installed on a pipeline. One outlet of the second-effect evaporator is connected to the second-effect separator, and the other outlet is connected to the third-effect evaporator. The top outlet of the second-effect separator is connected to the third-effect evaporator, and the bottom outlet is connected to the second-effect evaporator via a second-effect circulation pump installed on a pipeline. One outlet of the third-effect evaporator is connected to the third-effect separator. Another outlet is connected to the evaporative condensate tank. One outlet of the bottom of the triple-effect separator is connected to the triple-effect evaporator via a triple-effect circulating pump installed on the pipeline, and the other outlet is connected to the 18% hydrochloric acid tank via a hydrochloric acid discharge pump installed on the pipeline. The top outlet of the triple-effect separator is connected to the first-stage preheater and the first cooling device. One outlet of the first-stage preheater is connected to the evaporative condensate tank, and the other outlet is connected to the condenser. One outlet of the first cooling device is connected to the condenser, and the other outlet is connected to the 30% hydrochloric acid storage tank. One outlet of the condenser is connected to the vacuum pump unit, and the other outlet is connected to the evaporative condensate tank. One outlet of the vacuum pump unit is connected to the tail gas scrubbing tower, and the other outlet is connected to the vacuum sealing cooler. The outlet of the vacuum sealing cooler is connected to the vacuum pump unit. The top outlet of the evaporative condensate tank is connected to the condenser, and the bottom outlet is connected to the 30% hydrochloric acid storage tank via an evaporative condensate pump installed on the pipeline.

[0013] The distillation and extraction unit comprises: an 18% hydrochloric acid tank connected to a first hydrogen chloride distiller, a second hydrogen chloride distiller, a third hydrogen chloride distiller, and a 30% hydrochloric acid absorption tower via an 18% hydrochloric acid pump installed on a pipeline; the top outlets of the first, second, and third hydrogen chloride distillers are connected to a first cooler and a second cooler respectively; the bottom outlets of the first, second, and third hydrogen chloride distillers are connected to the top inlets of the first, second, and third hydrogen chloride distillers via a distillation circulation pump installed on a pipeline; the bottom outlets of the first, second, and third hydrogen chloride distillers are all connected to a secondary preheater; the outlet of the second cooler is connected to a 30% hydrochloric acid washing tower; the bottom outlet of the 30% hydrochloric acid washing tower is connected to an absorption circulation cooler via a 30% hydrochloric acid absorption circulation pump installed on a pipeline; and the top outlet of the absorption circulation cooler is connected to the 30% hydrochloric acid absorption tower.

[0014] The exhaust gas absorption unit is as follows: an alkaline solution and a calcium hydroxide emulsion are introduced into a calcium hydroxide emulsion tank. The calcium hydroxide emulsion tank is connected to an exhaust gas scrubbing tower. The bottom outlet of the exhaust gas scrubbing tower is connected to an exhaust gas scrubbing cooler through an exhaust gas scrubbing pump installed on a pipeline, and the top outlet is connected to an exhaust gas induced draft fan. The exhaust gas induced draft fan discharges the exhaust gas.

[0015] The sealing water unit consists of a sealing water tank supplied with circulating cooling water from a cooling tower, and mechanical seal water from each pump returning to each pump after heat exchange in the sealing water tank via a sealing water pump.

[0016] The three-stage preheater, single-effect evaporator, first hydrogen chloride distillation unit, second hydrogen chloride distillation unit, and third hydrogen chloride distillation unit of this invention are heated by external generated steam.

[0017] The condenser, absorption circulation cooler, vacuum sealed water cooler, and exhaust gas scrubbing cooler of this invention are supplied with circulating cooling water from a cooling tower.

[0018] The non-condensable gas discharged from the 18% hydrochloric acid tank, the first hydrogen chloride distillation apparatus, the second hydrogen chloride distillation apparatus, the third hydrogen chloride distillation apparatus, the 30% hydrochloric acid absorption tower, and the vacuum pump unit of this utility model is introduced into the tail gas scrubbing tower.

[0019] This utility model includes a first hydrogen chloride distillation unit, a second hydrogen chloride distillation unit, a third hydrogen chloride distillation unit, a 30% hydrochloric acid absorption tower, a vacuum pump unit, a calcium hydroxide emulsion tank, a sealed water tank, a tail gas scrubbing tower, a triple-effect separator, a double-effect separator, and a single-effect separator for supplying process water.

[0020] This invention has the following advantages over the prior art:

[0021] 1. The hydrochloric acid recovery rate of this device can typically reach 80%-95%, and the recovered acid concentration can be restored to over 30% (close to the industrial-grade hydrochloric acid standard), which can be directly reused in production. Some by-products (such as ferrous chloride) can also be sold as commodities. The process is mature, advanced, reasonable, and highly flexible, while also being energy-efficient and producing no secondary pollution. It achieves the goal of recovering useful resources from waste hydrochloric acid while simultaneously rendering the waste acid harmless.

[0022] 2. This device thoroughly treats exhaust gas, achieving compliance with emission standards through multi-stage absorption and eliminating secondary pollution.

[0023] 3. This device purifies low-concentration waste hydrochloric acid through processes such as concentration, distillation, and extraction to obtain hydrochloric acid that can be reused in production. This reduces the amount of new hydrochloric acid that enterprises need to purchase, directly lowering raw material costs. It is especially suitable for industries with huge hydrochloric acid consumption, such as steel, electroplating, and chemicals. Attached Figure Description

[0024] Figures 1-3 This is a structural schematic diagram of one embodiment of the present invention.

[0025] In the diagram: 1. Steam condensate pump; 2. Steam condensate tank; 3. Secondary preheater; 4. Tertiary preheater; 5. First-effect circulating pump; 6. Second-effect circulating pump; 7. Third-effect circulating pump; 8. Hydrochloric acid discharge pump; 9. Waste hydrochloric acid storage tank; 10. Hydrochloric acid feed pump; 11. Evaporation condensate tank; 12. Evaporation condensate pump; 13. 18% hydrochloric acid tank; 14. 18% hydrochloric acid pump; 15. First hydrogen chloride distiller; 16. Second hydrogen chloride distiller; 17. Third hydrogen chloride distiller; 18. Distillation circulation pump; 19. 30% hydrochloric acid absorption tower; 20. 30% hydrochloric acid absorption... 21. Absorption circulating pump; 22. Absorption circulating cooler; 23. Vacuum sealed water cooler; 24. Vacuum pump unit; 25. Calcium hydroxide emulsion tank; 26. Tail gas scrubbing circulating pump; 27. Tail gas scrubbing cooler; 28. Tail gas induced draft fan; 29. ​​Sealed water tank; 30. Sealed water pump; 31. Tail gas scrubbing tower; 32. Second cooler; 33. Condenser; 34. First cooler; 35. First stage preheater; 36. Triple-effect separator; 37. Triple-effect evaporator; 38. Second-effect separator; 39. First-effect evaporator; 40. First-effect evaporator. Detailed Implementation

[0026] 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.

[0027] Example 1

[0028] exist Figures 1-3The present invention relates to a waste hydrochloric acid concentration, distillation and extraction device, which includes an evaporation and concentration unit, a distillation and extraction unit, a tail gas treatment unit, and a sealing water unit.

[0029] The evaporation and concentration unit is as follows: hydrochloric acid from waste hydrochloric acid storage tank 9 sequentially enters the primary preheater 34, the secondary preheater 3, and the tertiary preheater 4. One outlet of the tertiary preheater 4 is connected to the first-effect separator 39, and the other outlet is connected to the secondary preheater 3. The bottom outlet of the first-effect separator 39 is connected to the first-effect evaporator 40 via a first-effect circulating pump 5 installed on a pipeline, and the top outlet is connected to the second-effect evaporator 38. One outlet of the first-effect evaporator 40 is connected to the secondary preheater 3, and the other outlet is connected to the first-effect separator 38. 9 are connected. The outlet of the secondary preheater 3 is connected to the steam condensate tank 2. The steam condensate tank 2 is connected to the boiler via the steam condensate pump 1 installed on the pipeline. One outlet of the second-effect evaporator 38 is connected to the second-effect separator 37, and the other outlet is connected to the third-effect evaporator 36. The top outlet of the second-effect separator 37 is connected to the third-effect evaporator 36, and the bottom outlet is connected to the second-effect evaporator 38 via the second-effect circulating pump 6 installed on the pipeline. One outlet of the third-effect evaporator 36 is connected to the third-effect separator 35, and the other outlet... The outlet of the triple-effect separator 35 is connected to the evaporator condensate tank 11. One outlet of the triple-effect separator 35 is connected to the triple-effect evaporator 36 via a triple-effect circulation pump 7 installed on a pipeline, and the other outlet is connected to the 18% hydrochloric acid tank 13 via a hydrochloric acid discharge pump 8 installed on a pipeline. The top outlet of the triple-effect separator 35 is connected to the first-stage preheater 34 and the first cooling device 33. One outlet of the first-stage preheater 34 is connected to the evaporator condensate tank 11, and the other outlet is connected to the condenser 32. One outlet of the first cooling device 33 is connected to the condenser 22. One outlet of the condenser 32 is connected to the vacuum pump unit 23, and the other outlet is connected to the evaporative condensate tank 11. One outlet of the vacuum pump unit 23 is connected to the tail gas scrubbing tower 30, and the other outlet is connected to the vacuum seal cooler 22. The outlet of the vacuum seal cooler 22 is connected to the vacuum pump unit 23. The top outlet of the evaporative condensate tank 11 is connected to the condenser 32, and the bottom outlet is connected to the 30% hydrochloric acid storage tank via the evaporative condensate pump 12 installed on the pipeline.

[0030] The distillation and extraction unit comprises: an 18% hydrochloric acid tank 13 connected to a first hydrogen chloride distiller 15, a second hydrogen chloride distiller 16, a third hydrogen chloride distiller 17, and a 30% hydrochloric acid absorption tower 19 via an 18% hydrochloric acid pump 14 installed on a pipeline; the top outlets of the first hydrogen chloride distiller 15, the second hydrogen chloride distiller 16, and the third hydrogen chloride distiller 17 are connected in one path to a first cooler 33 and in another path to a second cooler 31; and the bottom outlets of the first hydrogen chloride distiller 15, the second hydrogen chloride distiller 16, and the third hydrogen chloride distiller 17 are connected to a distillation unit installed on a pipeline. The distillation circulation pump 18 is connected to the top inlet of the first hydrogen chloride distiller 15, the second hydrogen chloride distiller 16, and the third hydrogen chloride distiller 17. The bottom outlet of the first hydrogen chloride distiller 15, the second hydrogen chloride distiller 16, and the third hydrogen chloride distiller 17 is connected to the secondary preheater 3. The outlet of the second cooler 31 is connected to the 30% hydrochloric acid washing tower 19. The bottom outlet of the 30% hydrochloric acid washing tower 19 is connected to the absorption circulation cooler 21 through the 30% hydrochloric acid absorption circulation pump 20 installed on the pipeline. The top outlet of the absorption circulation cooler 21 is connected to the 30% hydrochloric acid absorption tower 19.

[0031] The exhaust gas absorption unit is as follows: an alkaline solution and a calcium hydroxide emulsion are introduced into a calcium hydroxide emulsion tank 24. The calcium hydroxide emulsion tank 24 is connected to an exhaust gas scrubbing tower 30. The bottom outlet of the exhaust gas scrubbing tower 30 is connected to an exhaust gas scrubbing cooler 26 through an exhaust gas scrubbing pump 25 installed on a pipeline, and the top outlet is connected to an exhaust gas induced draft fan 27. The exhaust gas induced draft fan 27 discharges the exhaust gas.

[0032] The sealing water unit is as follows: the sealing water tank 28 is supplied with circulating cooling water from the cooling tower, and the mechanical seal water from each pump exchanges heat in the sealing water tank 28 and then returns to each pump through the sealing water pump 29.

[0033] In this embodiment, the three-stage preheater 4, the first-effect evaporator 40, the first hydrogen chloride distillation unit 15, the second hydrogen chloride distillation unit 16, and the third hydrogen chloride distillation unit 17 are heated by external live steam. The condenser 32, the absorption circulating cooler 21, the vacuum-sealed water cooler 22, and the tail gas scrubbing cooler 26 are supplied with circulating cooling water from a cooling tower. The non-condensable gases discharged from the 18% hydrochloric acid tank 13, the first hydrogen chloride distillation unit 15, the second hydrogen chloride distillation unit 16, the third hydrogen chloride distillation unit 17, the 30% hydrochloric acid absorption tower 19, and the vacuum pump unit 23 are fed into the tail gas scrubbing tower 30. Process water is supplied from the first hydrogen chloride distillation unit 15, the second hydrogen chloride distillation unit 16, the third hydrogen chloride distillation unit 17, the 30% hydrochloric acid absorption tower 19, the vacuum pump unit 23, the calcium hydroxide emulsion tank 24, the sealed water tank 28, the tail gas scrubbing tower 30, the triple-effect separator 35, the double-effect separator 37, and the first-effect separator 39.

[0034] The working principle of this utility model is as follows:

[0035] 1. Evaporation and Concentration System

[0036] Hydrochloric acid from waste hydrochloric acid storage tank 9 sequentially enters the primary, secondary, and tertiary preheaters, where it is preheated using secondary gas from a triple-effect separator, steam condensate, and live steam, respectively. The preheated waste hydrochloric acid then sequentially enters the primary, secondary, and tertiary evaporator groups for concentration. The concentrated hydrochloric acid is then transferred from the triple-effect separator 36 to the hydrochloric acid tank 13 via the hydrochloric acid discharge pump 8. Evaporation and concentration utilize a vacuum pump to maintain a system vacuum. Under negative pressure, the excess water in the waste hydrochloric acid is removed, increasing its concentration, based on the difference in boiling points between water and hydrochloric acid.

[0037] 2. Distillation and Extraction System

[0038] Hydrochloric acid from hydrochloric acid tank 13 is transferred to the first, second and third hydrogen chloride distillation vessels via hydrochloric acid pump 14. Calcium chloride dihydrate or calcium chloride solution is added to each vessel, and live steam is introduced into the vessel for heating and evaporation. The evaporated hydrochloric acid vapor enters the 30% hydrochloric acid absorption tower 19 and is cooled by the absorption circulation cooler 21 to obtain concentrated hydrochloric acid product.

[0039] 3. Exhaust gas treatment system

[0040] Non-condensable gas from the primary preheater 35 and the evaporative condensate tank 11 enters the vacuum pump unit 23 through the shell side of the condenser 33. After gas-liquid separation by the vacuum pump unit 23, the non-condensable gas enters the tail gas absorption tower. The tail gas from each storage tank and the hydrochloric acid absorption tower enters the tail gas scrubbing tower 31. The exhaust gas flows from bottom to top, and the scrubbing liquid flows from top to bottom. Through multiple cycles of countercurrent exchange with the tail gas, the tail gas in the tower is completely absorbed and discharged from the top of the tail gas tower, meeting emission standards.

[0041] 4. Waste hydrochloric acid concentration, distillation, and extraction device

[0042] 4.1) Material flow:

[0043] The material from the waste hydrochloric acid storage tank 9 is transferred sequentially into the first, second, and third stage preheaters by the hydrochloric acid feed pump 10. The waste hydrochloric acid then passes through the tubes of the preheaters and enters the first, second, and third effect evaporators in sequence. The material is circulated in the evaporators and separators by the circulation pumps of each effect. The concentrated hydrochloric acid enters the hydrochloric acid tank 13 through the hydrochloric acid discharge pump 8.

[0044] The 13% hydrochloric acid pump 14 pumps the hydrochloric acid from the 13% hydrochloric acid tank 13 into the first, second, and third hydrogen chloride distillers. The hydrogen chloride vapor from the distillers enters the 30% hydrochloric acid absorption tower 13 for absorption. The absorption circulation cooler 21 is used to cool the product and obtain hydrochloric acid.

[0045] 4.2) Heating Steam Process:

[0046] The raw steam from the outside first enters the material in the shell side of the first-effect evaporator 41 and the heating tube side. The heated material undergoes flash evaporation and vapor-liquid separation in the first-effect separator 40. The generated secondary steam then enters the material in the shell side of the second-effect evaporator 39 and the heating tube side. The heated material undergoes flash evaporation and vapor-liquid separation in the second-effect separator 38. The generated secondary steam then enters the material in the shell side of the third-effect evaporator 37 and the heating tube side. Finally, part of the generated secondary steam enters the shell side of the condenser 33 and is condensed, while part enters the shell side of the first-stage preheater 35 to preheat the material in the tube side.

[0047] A portion of the live steam from the outside enters the shell side of the third-stage preheater to heat the material in the tube side of the preheater.

[0048] Some of the live steam from the outside enters the shell process of the first, second, and third hydrogen chloride distillers to heat the material inside the vessel.

[0049] 4.3) Condensate flow:

[0050] a. Steam condensate flow: The steam condensate from the shell side of the first-effect evaporator 41 flows to the steam condensate tank 2 by pressure difference. During the process, it is preheated by the secondary preheater 3 and finally pumped out by the steam condensate pump 1 for reuse.

[0051] Steam condensate from the shell side of the tertiary preheater 4 and steam condensate from the shell sides of the first, second, and third hydrogen chloride distillers flow to steam condensate tank 2 by pressure difference. During this process, the system feed is preheated by the secondary preheater 3, and finally pumped out by steam condensate pump 1 for reuse.

[0052] b. Evaporation condensate flow: The evaporation condensate in the shell side of the second-effect evaporator 39 flows to the shell side of the third-effect evaporator 37 by pressure difference, and flows into the evaporation condensate tank 11 along with the steam condensate in the shell side of the third-effect evaporator 37.

[0053] The evaporative condensate from the shell side of the first-stage preheater 35 flows into the evaporative condensate tank 11 by pressure difference.

[0054] A portion of the evaporative condensate in the evaporative condensate tank 11 is pumped into the first cooler 34 by the evaporative condensate pump 12, while the other portion is reused or sent to the sewage treatment plant for further treatment.

[0055] 4.4) Vacuum system process:

[0056] The vacuum system consists of an evaporation condensate tank 11, a condenser 33, and a vacuum pump unit 23. The condenser 33 condenses the secondary steam generated in the triple-effect separator 36. The vacuum pump extracts non-condensable gases (organic gases, steam, air, or other non-condensable gases) from the system and sends them to the vacuum pump unit 23 for gas-liquid separation. Finally, the non-condensable gases from the vacuum pump unit 23 are discharged uniformly. At the same time, the vacuum pump maintains the vacuum level required for the entire evaporation crystallization system.

Claims

1. A waste hydrochloric acid concentration, distillation, and extraction apparatus, characterized in that: It includes an evaporation and concentration unit, a distillation and extraction unit, a tail gas treatment unit, and a sealing water unit; The evaporation and concentration unit is as follows: hydrochloric acid from the waste hydrochloric acid storage tank (9) enters the first-stage preheater (34), the second-stage preheater (3), and the third-stage preheater (4) in sequence. One outlet of the third-stage preheater (4) is connected to the first-effect separator (39), and the other outlet is connected to the second-stage preheater (3). The bottom outlet of the first-effect separator (39) is connected to the first-effect evaporator (40) through a first-effect circulating pump (5) installed on the pipeline, and the top outlet is connected to the second-effect evaporator (38). One outlet of the first-effect evaporator (40) is connected to the second-stage preheater (3), and the other outlet is connected to the first-effect separator (38). 39) Connected, the outlet of the secondary preheater (3) is connected to the steam condensate tank (2), the steam condensate tank (2) is connected to the boiler through the steam condensate pump (1) installed on the pipeline, one outlet of the second-effect evaporator (38) is connected to the second-effect separator (37), and the other outlet is connected to the third-effect evaporator (36), the top outlet of the second-effect separator (37) is connected to the third-effect evaporator (36), and the bottom outlet is connected to the second-effect evaporator (38) through the second-effect circulating pump (6) installed on the pipeline, one outlet of the third-effect evaporator (36) is connected to the third-effect separator (35), and the other outlet is connected to the third-effect evaporator (38). One outlet is connected to the evaporating condensate tank (11). The bottom outlet of the triple-effect separator (35) is connected to the triple-effect evaporator (36) via a triple-effect circulating pump (7) installed on a pipeline, and to the 18% hydrochloric acid tank (13) via a hydrochloric acid discharge pump (8) installed on a pipeline. The top outlet of the triple-effect separator (35) is connected to the first-stage preheater (34) and the first cooling device (33). One outlet of the first-stage preheater (34) is connected to the evaporating condensate tank (11), and the other outlet is connected to the condenser (32). One outlet of the first cooling device (33) is connected to the condenser (2). 2) One outlet of the condenser (32) is connected to the vacuum pump unit (23), and the other outlet is connected to the evaporation condensate tank (11). One outlet of the vacuum pump unit (23) is connected to the tail gas scrubbing tower (30), and the other outlet is connected to the vacuum seal cooler (22). The outlet of the vacuum seal cooler (22) is connected to the vacuum pump unit (23). The top outlet of the evaporation condensate tank (11) is connected to the condenser (32), and the bottom outlet is connected to the 30% hydrochloric acid storage tank through the evaporation condensate pump (12) installed on the pipeline. The distillation and extraction unit is as follows: an 18% hydrochloric acid tank (13) is connected to the first hydrogen chloride distillation vessel (15), the second hydrogen chloride distillation vessel (16), the third hydrogen chloride distillation vessel (17), and the 30% hydrochloric acid absorption tower (19) via an 18% hydrochloric acid pump (14) installed on a pipeline. The top outlets of the first hydrogen chloride distillation vessel (15), the second hydrogen chloride distillation vessel (16), and the third hydrogen chloride distillation vessel (17) are connected to the first cooler (33) on one side and to the second cooler (31) on the other side. The bottom outlets of the first hydrogen chloride distillation vessel (15), the second hydrogen chloride distillation vessel (16), and the third hydrogen chloride distillation vessel (17) are connected to the distillation unit installed on a pipeline. The circulating pump (18) is connected to the top inlet of the first hydrogen chloride distillation vessel (15), the second hydrogen chloride distillation vessel (16), and the third hydrogen chloride distillation vessel (17). The bottom outlets of the first hydrogen chloride distillation vessel (15), the second hydrogen chloride distillation vessel (16), and the third hydrogen chloride distillation vessel (17) are all connected to the secondary preheater (3). The outlet of the second cooler (31) is connected to the 30% hydrochloric acid washing tower (19). The bottom outlet of the 30% hydrochloric acid washing tower (19) is connected to the absorption circulating cooler (21) through the 30% hydrochloric acid absorption circulating pump (20) installed on the pipeline. The top outlet of the absorption circulating cooler (21) is connected to the 30% hydrochloric acid absorption tower (19). The exhaust gas absorption unit is as follows: an alkaline solution and a calcium hydroxide emulsion are introduced into a calcium hydroxide emulsion tank (24). The calcium hydroxide emulsion tank (24) is connected to an exhaust gas scrubbing tower (30). The bottom outlet of the exhaust gas scrubbing tower (30) is connected to an exhaust gas scrubbing cooler (26) through an exhaust gas scrubbing pump (25) installed on a pipeline, and the top outlet is connected to an exhaust gas induced draft fan (27). The exhaust gas induced draft fan (27) discharges the exhaust gas. The sealing water unit is as follows: the sealing water tank (28) is supplied with circulating cooling water by the cooling tower, and the mechanical seal water from each pump exchanges heat in the sealing water tank (28) and then returns to each pump through the sealing water pump (29).

2. The waste hydrochloric acid concentration, distillation, and extraction apparatus according to claim 1, characterized in that: The three-stage preheater (4), the first-effect evaporator (40), the first hydrogen chloride distillation unit (15), the second hydrogen chloride distillation unit (16), and the third hydrogen chloride distillation unit (17) are heated by external live steam.

3. The waste hydrochloric acid concentration, distillation, and extraction apparatus according to claim 1, characterized in that: The condenser (32), absorption circulation cooler (21), vacuum sealed water cooler (22), and exhaust gas scrubbing cooler (26) are supplied with circulating cooling water by a cooling tower.

4. The waste hydrochloric acid concentration, distillation, and extraction apparatus according to claim 1, characterized in that: The non-condensable gas discharged from the 18% hydrochloric acid tank (13), the first hydrogen chloride distillation unit (15), the second hydrogen chloride distillation unit (16), the third hydrogen chloride distillation unit (17), the 30% hydrochloric acid absorption tower (19), and the vacuum pump unit (23) is introduced into the tail gas scrubbing tower (30).

5. The waste hydrochloric acid concentration, distillation, and extraction apparatus according to claim 1, characterized in that: The first hydrogen chloride distiller (15), the second hydrogen chloride distiller (16), the third hydrogen chloride distiller (17), the 30% hydrochloric acid absorption tower (19), the vacuum pump unit (23), the calcium hydroxide emulsion tank (24), the sealed water tank (28), the tail gas scrubbing tower (30), the triple-effect separator (35), the double-effect separator (37), and the single-effect separator (39) supply process water.

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