Nitric acid-containing waste liquid treatment device

Abstract

The utility model relates to the field of hazardous waste treatment equipment, in particular to a nitric acid-containing waste liquid treatment device which comprises a pipe network unit, a waste gas collection unit, a solid-liquid separation unit and an evaporative crystallization unit, the waste gas collection unit, the solid-liquid separation unit and the evaporative crystallization unit are communicated in a closed loop mode through the pipe network unit, and the waste gas collection unit is provided with a front groove and a waste gas dissolving groove; the solid-liquid separation unit is provided with a neutralization precipitation tank; a first heat exchange pipe and a second heat exchange pipe are respectively arranged in a neutralization precipitation tank and a front tank, cold water is injected into the first heat exchange pipe to absorb heat energy generated by neutralization reaction in the neutralization precipitation tank, and water liquid absorbing the heat energy flows into the second heat exchange pipe to release the heat energy so as to promote waste liquid in the front tank to quickly volatilize acid gas. And the gas is collected by the waste gas dissolving tank, and condensate water discharged by the evaporative crystallization unit and water flowing out of the second heat exchange pipe are drained into the waste gas dissolving tank, so that the collected acid waste gas is dissolved into an acid solution to facilitate recovery, and therefore, the environment can be protected, and resource waste can be reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of hazardous waste treatment equipment, and particularly relates to a waste liquid containing nitric acid treatment device. BACKGROUND

[0002] The chemical industry often produces waste liquid containing nitric acid that needs to be treated. Nitric acid is a volatile and highly corrosive acid. Currently, the waste liquid containing nitric acid is mostly neutralized by an acid-base reaction to form a nitrate solution. The solid matter and impurities in the nitrate solution are then separated by precipitation. The separated liquid is then subjected to secondary separation by evaporation, crystallization, and condensation. The crystallized material can be recycled, but the condensed water is mostly discharged freely. Since there is still a small amount of acidic substance in the condensed water, it will affect the surrounding environment if not collected and treated. In addition, the waste liquid containing nitric acid is prone to emit acidic waste gas during the treatment process. If not collected and treated, the waste gas will also spread into the air and affect the surrounding environment. Furthermore, a large amount of heat is generated during the neutralization reaction of the waste liquid containing nitric acid. If not cooled, the heat will spread into the air, wasting energy and affecting the surrounding environment. In view of the above, if there is a waste liquid containing nitric acid treatment device that can absorb the heat generated during the neutralization reaction of the waste liquid and utilize it to promote the rapid volatilization of the waste liquid, and also utilize the volatilized waste gas and the condensed water after evaporation to dissolve the waste gas, it can avoid the unorganized discharge of the discharge during the treatment of the waste liquid, which causes new pollution to the surrounding environment, and how to better utilize the energy during the treatment process, which is the problem to be solved by the present case. SUMMARY

[0003] The utility model discloses a waste liquid containing nitric acid processing apparatus, including pipe network unit and by pipe network unit closed loop intercommunication's waste gas collection unit, solid -liquid separation unit, evaporative crystallization unit, waste gas collection unit be equipped with front -positioned groove and be placed in front -positioned groove downstream for collecting acid gas and the waste gas dissolving groove of acid gas dissolving to water, solid -liquid separation unit is equipped with neutralization precipitation groove, and neutralization precipitation groove and front -positioned groove are equipped with first heat exchange pipe and second heat exchange pipe respectively.

[0004] To achieve the above object, the utility model adopts the technical scheme as follows:

[0005] The application relates to a device for treating waste liquid containing nitric acid, which comprises an evaporation crystallization unit provided with an evaporation crystallizer for separating solute from solvent in a solution through evaporation, crystallization and condensation, characterized in that the device further comprises a waste gas collecting unit, a solid-liquid separating unit and a pipe network unit, the waste gas collecting unit is provided with a pre-tank for promoting the waste liquid to emit acidic gas and a waste gas dissolving tank arranged downstream of the pre-tank for collecting the acidic gas and dissolving the acidic gas into water, the solid-liquid separating unit is provided with a neutralization and precipitation tank for carrying out neutralization reaction on the waste liquid and precipitating solid, the neutralization and precipitation tank of the solid-liquid separating unit and the pre-tank of the waste gas collecting unit are respectively provided with a first heat exchange pipe and a second heat exchange pipe for heat exchange through water flow, the first heat exchange pipe is communicated with the second heat exchange pipe, the first heat exchange pipe can be injected with cold water and can absorb the heat energy generated by the neutralization reaction in the neutralization and precipitation tank, and the water after absorbing the heat energy can flow into the second heat exchange pipe to release the heat energy and promote the waste liquid in the pre-tank to emit acidic gas quickly, the waste gas collecting unit, the solid-liquid separating unit and the evaporation crystallization unit are arranged side by side in sequence and communicated with each other through the pipe network unit, and the condensate water from the evaporation crystallization unit and the water flowing out of the second heat exchange pipe can both flow into the waste gas dissolving tank of the waste gas collecting unit to dissolve the collected acidic waste gas into acidic solution.

[0006] The pipe network unit comprises a waste liquid feeding pipe, a waste liquid conveying pipe, a first sewage pump, a medicament feeding pipe, a cold water input pipe, a separated liquid discharging pipe, a separated liquid conveying pipe, a second sewage pump, a condensate water discharging pipe, a pipe pump, a waste gas conveying pipe, an air pump, a gas collecting cover, a heat exchange water conveying pipe, a heat exchange water discharging pipe, a heat exchange water recycling pipe, a water pump, a filtrate discharging pipe, a filtrate conveying pipe and a third sewage pump.

[0007] The waste gas collecting unit further comprises a heat exchange water collecting tank, the pre-tank, the heat exchange water collecting tank and the waste gas dissolving tank are all tank-shaped bodies provided with sealing covers at the top, the second heat exchange pipe is a spiral heat conducting pipe, and the second heat exchange pipe is fixedly connected to the inner wall of the pre-tank.

[0008] The waste liquid feeding pipe and the gas collecting cover are arranged at the upper part of the pre-tank, the outlet end of the waste liquid feeding pipe and the gas collecting cover are both arranged in the pre-tank, the gas collecting cover is communicated with the waste gas dissolving tank through the waste gas conveying pipe, the air pump is arranged on the waste gas conveying pipe, the heat exchange water collecting tank is communicated with the waste gas dissolving tank through the heat exchange water recycling pipe, and the water pump is connected to the water inlet end of the heat exchange water recycling pipe.

[0009] The solid-liquid separation unit further comprises a filter residue collecting tank, a filtrate collecting tank and a filter press, the filter residue collecting tank and the filtrate collecting tank are both tank-like bodies with a sealing cover at the top, the filter residue collecting tank is arranged side by side with the filtrate collecting tank, the neutralization and precipitation tank, the filter press and the filter residue collecting tank are sequentially arranged from top to bottom, the neutralization and precipitation tank is a cavity tank body with a conical lower part, a sealing cover is arranged at the top of the neutralization and precipitation tank, a discharge valve is arranged at the bottom of the neutralization and precipitation tank, an outlet of the discharge valve is communicated with a feed inlet of the filter press, a filter residue outlet of the filter press is communicated with the filter residue collecting tank, and a filtrate outlet of the filter press is communicated with the filtrate collecting tank through a filtrate discharge pipe.

[0010] The first heat exchange pipe is a spiral heat conducting pipe, the first heat exchange pipe is fixedly connected to the inner wall of the neutralization and precipitation tank, the cold water input pipe is connected to the inlet end of the first heat exchange pipe, the first heat exchange pipe is communicated with the second heat exchange pipe through a heat exchange water conveying pipe, and an electric heating wire can be further arranged on the pipe wall of the heat exchange water conveying pipe.

[0011] The medicament feeding pipe is arranged at the upper part of the neutralization and precipitation tank, the outlet end of the medicament feeding pipe is arranged in the neutralization and precipitation tank, the neutralization and precipitation tank is communicated with the pre-tank through a waste liquid conveying pipe, the first sewage pump is connected to the inlet end of the waste liquid conveying pipe and arranged in the pre-tank, the neutralization and precipitation tank is communicated with the filtrate collecting tank through a filtrate conveying pipe, and the third sewage pump is connected to the inlet end of the filtrate conveying pipe and arranged in the filtrate collecting tank.

[0012] The evaporation and crystallization unit further comprises a separation liquid collecting tank, the separation liquid collecting tank is a tank-like body with a sealing cover at the top, the separation liquid collecting tank is communicated with the neutralization and precipitation tank through a separation liquid discharge pipe, the inlet end of the separation liquid discharge pipe is arranged at the middle part of the neutralization and precipitation tank and the inlet end of the separation liquid discharge pipe is higher than the top surface of the separation liquid collecting tank, the separation liquid in the neutralization and precipitation tank can flow into the separation liquid collecting tank, and a filter screen is arranged at the inlet end of the separation liquid discharge pipe.

[0013] The evaporation and crystallization device is an evaporation and crystallization device capable of separating solute from solvent in a solution through evaporation, crystallization and condensation, the separation liquid collecting tank is communicated with the feed inlet of the evaporation and crystallization device through a separation liquid conveying pipe, the second sewage pump is connected to the inlet end of the separation liquid conveying pipe and arranged in the separation liquid collecting tank, the condensate water outlet of the evaporation and crystallization device is communicated with the waste gas dissolving tank through a condensate water discharge pipe, and the pipeline pump is connected to the condensate water discharge pipe.

[0014] From the above description, the waste liquid treatment device containing nitric acid has the advantages that: the waste gas collecting unit, the solid-liquid separation unit and the evaporation crystallization unit are connected in a closed loop through the pipe network unit, the first heat exchange pipe and the second heat exchange pipe which are in communication with each other are arranged in the neutralization and precipitation tank of the solid-liquid separation unit and the pre-tank of the waste gas collecting unit respectively, the first heat exchange pipe is used to inject cold water to absorb the heat energy generated by the neutralization reaction in the neutralization and precipitation tank, and the water liquid after absorbing the heat energy is flowed into the second heat exchange pipe to release the heat energy, so that the waste liquid in the pre-tank can volatilize the acidic gas quickly, the volatilized acidic gas is collected by the waste gas dissolving tank of the waste gas collecting unit, and the condensed water after evaporation and condensation of the evaporation crystallization unit and the water liquid flowed out of the second heat exchange pipe are drained into the waste gas dissolving tank to dissolve the collected acidic waste gas into an acidic solution, so that the heat energy generated by the neutralization reaction can be absorbed and utilized, the environment can be protected, and the resource waste can be reduced. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is a general schematic view of the waste liquid treatment device containing nitric acid.

[0016] Figure 2 It is an enlarged schematic view of the waste gas collecting unit.

[0017] Figure 3 It is an enlarged schematic view of the solid-liquid separation unit.

[0018] Figure 4 It is an enlarged schematic view of the evaporation crystallization unit.

[0019] Figure 5 It is a schematic view of the pipe network unit.

[0020] Reference signs:

[0021] 1 Waste gas collection unit; 11 Pre-tank; 12 Heat exchange water collection tank; 13 Waste gas dissolution tank; 14 Second heat exchange pipe; 2 Solid-liquid separation unit; 21 Neutralization sedimentation tank; 22 Filter residue collection tank; 23 Filtrate collection tank; 24 Filter press; 25 First heat exchange pipe; 26 Drain valve; 3 Evaporation crystallization unit; 31 Separation liquid collection tank; 32 Evaporation crystallizer; 4 Pipe network unit; 401 Waste liquid delivery pipe; 402 Waste liquid delivery pipe; 403 First sewage pump; 40 4. Chemical injection pipe; 405. Cold water input pipe; 406. Separation liquid discharge pipe; 407. Separation liquid delivery pipe; 408. Second sewage pump; 409. Condensate discharge pipe; 410. Pipeline pump; 411. Exhaust gas delivery pipe; 412. Vacuum pump; 413. Gas collecting hood; 414. Heat exchange water delivery pipe; 415. Heat exchange water discharge pipe; 416. Heat exchange water recycling pipe; 417. Water pump; 418. Filtrate discharge pipe; 419. Filtrate delivery pipe; 420. Third sewage pump. DETAILED DESCRIPTION

[0022] The present invention is further described below through specific implementation methods.

[0023] like Figure 1 As shown, the waste liquid treatment device containing nitric acid described in the utility model includes a waste gas collection unit 1, a solid-liquid separation unit 2, an evaporation crystallization unit 3 and a pipe network unit 4. The waste gas collection unit 1, the solid-liquid separation unit 2, and the evaporation crystallization unit 3 are arranged side by side in sequence and are interconnected by the pipe network of the pipe network unit 4.

[0024] like Figure 1 and Figure 5 As shown, the pipe network unit 4 described in the present invention includes a waste liquid delivery pipe 401, a waste liquid conveying pipe 402, a first sewage pump 403, a drug delivery pipe 404, a cold water input pipe 405, a separation liquid discharge pipe 406, a separation liquid delivery pipe 407, a second sewage pump 408, a condensate discharge pipe 409, a pipeline pump 410, an exhaust gas delivery pipe 411, an air pump 412, an air collecting hood 413, a heat exchange water delivery pipe 414, a heat exchange water discharge pipe 415, a heat exchange water return pipe 416, a water pump 417, a filtrate discharge pipe 418, a filtrate delivery pipe 419 and a third sewage pump 420.

[0025] like Figure 1 、 Figure 2 and Figure 5As shown, the waste gas collecting unit 1 includes a pre-tank 11, a heat exchange water collecting tank 12, a waste gas dissolving tank 13 and a second heat exchange pipe 14, the pre-tank 11 is used for promoting the emission of acidic gas from the nitric acid waste liquid, the waste gas dissolving tank 13 is arranged downstream of the pre-tank 11 and is used for collecting the acidic gas and dissolving the acidic gas into water, the pre-tank 11, the heat exchange water collecting tank 12 and the waste gas dissolving tank 13 are all tank-shaped bodies provided with sealing covers at the top, the second heat exchange pipe 14 is a spiral heat conducting pipe, and the second heat exchange pipe 14 is fixedly connected to the inner wall of the pre-tank 11. The waste liquid feeding pipe 401 and the gas collecting cover 413 are arranged at the upper part of the pre-tank 11, the outlet end of the waste liquid feeding pipe 401 and the gas collecting cover 413 are both arranged in the pre-tank 11, the gas collecting cover 413 and the waste gas dissolving tank 13 are communicated by a waste gas conveying pipe 411, a gas suction pump 412 is arranged on the waste gas conveying pipe 411, the heat exchange water collecting tank 12 and the waste gas dissolving tank 13 are communicated by a heat exchange water recycling pipe 416, and the water suction pump 417 is connected to the water inlet end of the heat exchange water recycling pipe 416.

[0026] As Figure 1 , Figure 2 , Figure 3 and Figure 5The utility model discloses a solid -liquid separation unit 2 including neutralization sedimentation tank 21, filter residue collection tank 22, filtrate collection tank 23, filter press 24, first heat exchange tube 25 and blowdown valve 26, and the filter press 24 is the public known technology. Neutralization sedimentation tank 21 is used for neutralization reaction to nitric acid waste liquid and makes solid deposit, and filter residue collection tank 22 and filtrate collection tank 23 are all the tank -like body with the sealing cover being equipped at the top, and filter residue collection tank 22 is arranged side by side with filtrate collection tank 23, and neutralization sedimentation tank 21, filter press 24 and filter residue collection tank 22 are sequentially arranged from top to bottom, and the neutralization sedimentation tank 21 is the cavity tank body with the cone shape in lower part, and is equipped with the sealing cover at the top, and the bottom of neutralization sedimentation tank 21 is equipped with the outlet with blowdown valve 26, and the outlet is communicated with the feed inlet of filter press 24, and the filter residue outlet of filter press 24 is communicated with filter residue collection tank 22, and the filtrate outlet of filter press 24 and filtrate collection tank 23 are communicated by filtrate discharge pipe 418. The first heat exchange tube 25 is the spiral heat conduction pipe, and first heat exchange tube 25 is fixedly connected on the inner wall of neutralization sedimentation tank 21, cold water input pipe 405 is connected at the inlet end of first heat exchange tube 25, and first heat exchange tube 25 and second heat exchange tube 14 are communicated by heat exchange water delivery pipe 414, and first heat exchange tube 25 can inject cold water by cold water input pipe 405 and can absorb the heat energy generated in neutralization reaction in neutralization sedimentation tank 21, and the water liquid after absorbing heat energy can flow into second heat exchange tube 14 to release heat energy to promote the rapid emission of acidic gas of waste liquid in front tank 11, and the electric heating wire is also arranged on the pipe wall of heat exchange water delivery pipe 414. The medicament delivery pipe 404 is arranged at the upper part of neutralization sedimentation tank 21, and the outlet end is placed in neutralization sedimentation tank 21, and neutralization sedimentation tank 21 and front tank 11 are communicated by waste liquid delivery pipe 402, and the first sewage pump 403 is connected at the inlet end of waste liquid delivery pipe 402 and is placed in front tank 11, and neutralization sedimentation tank 21 and filtrate collection tank 23 are communicated by filtrate delivery pipe 419, and the third sewage pump 420 is connected at the inlet end of filtrate delivery pipe 419 and is placed in filtrate collection tank 23.

[0027] As Figures 1 to 5As shown, the evaporation crystallization unit 3 includes a separation liquid collecting groove 31 and an evaporation crystallizer 32, the separation liquid collecting groove 31 is a groove-shaped body provided with a sealing cover at the top, the separation liquid collecting groove 31 and the neutralization precipitation groove 21 are communicated by a separation liquid discharge pipe 406, the inlet end of the separation liquid discharge pipe 406 is arranged in the middle of the neutralization precipitation groove 21 and the inlet end of the separation liquid discharge pipe 406 is higher than the top surface of the separation liquid collecting groove 31, the separation liquid in the neutralization precipitation groove 21 can flow into the separation liquid collecting groove 31 by itself, and the inlet end of the separation liquid discharge pipe 406 is also provided with a filter screen. The evaporation crystallizer 32 is an evaporation crystallization device that can separate solute and solvent in solution by evaporation, crystallization and condensation, and the evaporation crystallizer 32 is a known technology. The separation liquid collecting groove 31 and the inlet of the evaporation crystallizer 32 are communicated by a separation liquid conveying pipe 407, the second sewage pump 408 is connected to the inlet end of the separation liquid conveying pipe 407 and arranged in the separation liquid collecting groove 31, the condensate water outlet of the evaporation crystallizer 32 and the waste gas dissolving groove 13 are communicated by a condensate water discharge pipe 409, and the pipeline pump 410 is connected to the condensate water discharge pipe 409. The condensate water and the water liquid flowing out of the second heat exchange pipe 14 after evaporation and condensation of the evaporation crystallization unit 3 can flow into the waste gas dissolving groove 13 of the waste gas collecting unit 1 to dissolve the collected acidic waste gas into acidic solution.

[0028] The use method of the waste liquid containing nitric acid treatment device is as follows:

[0029] Before use, the waste liquid feeding pipe 401, the medicament feeding pipe 404 and the cold water input pipe 405 are respectively connected with the external waste liquid pipe network containing nitric acid or storage bin, medicament feeding device for neutralizing nitric acid and tap water pipe network; the evaporation crystallizer 32 is connected with the external heat supply system. The first sewage pump 403, the second sewage pump 408, the third sewage pump 420, the pipeline pump 410, the water pump 417 and the air pump 412 are started.

[0030] The waste liquid containing nitric acid is poured into the pre-tank 11, and the acid waste gas volatilized from the nitric acid is sent into the waste gas dissolving tank 13 through the gas hood 413, the air pump 412 and the waste gas conveying pipe 411. If the heat exchange water conveying pipe 414 is provided with an electric heating wire, the water in the heat exchange water conveying pipe 414 can be temporarily heated by the electric heating wire to temporarily promote the rapid volatilization of the nitric acid in the waste liquid in the pre-tank 11 when the first heat exchange pipe 25 has not started heat exchange. If the heat exchange water conveying pipe 414 is not provided with an electric heating wire, it can also not be preheated. The waste gas volatilized waste liquid containing nitric acid is sent into the neutralization and precipitation tank 21 by the first sewage pump 403 and the waste liquid conveying pipe 402, and an alkaline reagent is poured into the neutralization and precipitation tank 21. The waste liquid containing nitric acid will have a neutralization reaction and generate heat to rapidly heat the cold water in the first heat exchange pipe 25 for heat exchange. The hot water after heat exchange in the first heat exchange pipe 25 flows into the second heat exchange pipe 14 through the heat exchange water conveying pipe 414. The second heat exchange pipe 14 uses heat exchange to heat the waste liquid containing nitric acid in the pre-tank 11 to promote the rapid volatilization of the nitric acid in the waste liquid in the pre-tank 11. The water temperature in the second heat exchange pipe 14 is reduced after heat exchange, and the cooled water flows into the heat exchange water collecting tank 12 for storage and natural cooling. The water in the heat exchange water collecting tank 12 is periodically pumped into the waste gas dissolving tank 13. The acid waste gas volatilized from the pre-tank 11 is sent into the waste gas dissolving tank 13 for storage and dissolved into an acid solution with the water in the tank.

[0031] After the waste liquid in the neutralization and precipitation tank 21 is neutralized, the solid and impurities precipitate to the bottom, and the separated liquid after clarification is stored in the separated liquid collecting tank 31 through the separated liquid discharge pipe 406. The solid and impurities precipitated to the bottom are periodically sent into the filter press 24 through the outlet with the blowdown valve 26 for pressure filtration, and the filter residue and filtrate after pressure filtration are collected in the filter residue collecting tank 22 and the filtrate collecting tank 23, respectively. The filtrate is returned to the neutralization and precipitation tank 21 by the third sewage pump 420 and the filtrate conveying pipe 419.

[0032] The separated liquid stored in the separated liquid collecting tank 31 is sent into the evaporation and crystallization device 32 by the second sewage pump 408 and the separated liquid conveying pipe 407 for evaporation, crystallization and condensation to separate the solute and solvent in the separated liquid. The solvent evaporated into steam is condensed into condensed water, which is sent into the waste gas dissolving tank 13 by the pipe pump 410 and the condensed water discharge pipe 409 to participate in the dissolution of the waste gas in the tank.

[0033] The utility model discloses a waste liquid containing nitric acid treatment device, waste gas collection unit 1, solid -liquid separation unit 2, evaporation crystallization unit 3 are communicated with pipe network unit 4 and are closed loop in the inside of neutralization precipitation tank 21 of solid -liquid separation unit 2 and the pre -tank 11 of waste gas collection unit 1 respectively are equipped with the first heat pipe 25 and second heat pipe 14 of intercommunication, utilize the first heat pipe 25 and inject cold water to absorb the heat energy of the neutralization reaction that neutralization precipitation tank 21 in, and the water liquid after heat energy absorption flows into second heat pipe 14 to carry out heat energy release to promote the waste liquid in pre -tank 11 and emit acid gas fast, and the acid gas of volatilization is collected by the waste gas dissolving tank 13 of waste gas collection unit 1 and the condensed water of evaporation crystallization unit 3 evaporation condensation and the water liquid of second heat pipe 14 flow out are introduced into waste gas dissolving tank 13 to make the acid waste gas of collection dissolve into acid solution to facilitate recovery, thereby can avoid the emission of waste liquid treatment and cause new pollution to the surrounding environment during unorganized emission and the heat energy of neutralization reaction produces absorption utilization, can protect the environment and reduce resource waste.

[0034] The above is only one specific embodiment of the utility model, but the design concept of the utility model is not limited to this, and any non-essential change of the utility model by using the concept should belong to the act of infringing the protection scope of the utility model.

Claims

1. An apparatus for treating a waste solution containing nitric acid, comprising an evaporative crystallization unit (3) provided with an evaporative crystallizer (32) capable of separating a solute from a solvent in a solution by evaporation, crystallization and condensation, characterized in that: The waste gas collection unit (1) is provided with a pre-tank (11) and a waste gas dissolving tank (13) arranged downstream of the pre-tank (11), the neutralization and precipitation tank (21) of the solid-liquid separation unit (2) and the pre-tank (11) of the waste gas collection unit (1) are respectively provided with first and second heat exchange pipes (25 and 14) for heat exchange through water flow, the first heat exchange pipe (25) is communicated with the second heat exchange pipe (14), the waste gas collection unit (1), the solid-liquid separation unit (2) and the evaporation crystallization unit (3) are arranged side by side in sequence and are communicated with each other by the pipe network unit (4), the condensed water from the evaporation crystallization unit (3) and the water from the second heat exchange pipe (14) can both flow into the waste gas dissolving tank (13) of the waste gas collection unit (1).

2. The apparatus for treating a waste liquid containing nitric acid according to claim 1, characterized by: The pipe network unit (4) comprises a waste liquid feeding pipe (401), a waste liquid conveying pipe (402), a first sewage pump (403), a medicament feeding pipe (404), a cold water input pipe (405), a separated liquid discharging pipe (406), a separated liquid conveying pipe (407), a second sewage pump (408), a condensed water discharging pipe (409), a pipe pump (410), a waste gas conveying pipe (411), an air pump (412), a gas collecting cover (413), a heat exchange water conveying pipe (414), a heat exchange water discharging pipe (415), a heat exchange water recycling pipe (416), a water pump (417), a filtrate discharging pipe (418), a filtrate conveying pipe (419) and a third sewage pump (420).

3. The apparatus for treating a waste liquid containing nitric acid according to claim 2, characterized by: The waste gas collection unit (1) further comprises a heat exchange water collecting tank (12), the pre-tank (11), the heat exchange water collecting tank (12) and the waste gas dissolving tank (13) are all tank-shaped bodies provided with sealing covers at the top, and the second heat exchange pipe (14) is a spiral heat conducting pipe which is fixedly connected to the inner wall of the pre-tank (11).

4. The apparatus for treating a waste liquid containing nitric acid according to claim 3, characterized by: The waste liquid feeding pipe (401) and the gas collecting cover (413) are arranged at the upper part of the pre-tank (11), the outlet end of the waste liquid feeding pipe (401) and the gas collecting cover (413) are both arranged in the pre-tank (11), the gas collecting cover (413) and the waste gas dissolving tank (13) are communicated by the waste gas conveying pipe (411), the air pump (412) is arranged on the waste gas conveying pipe (411), the heat exchange water collecting tank (12) and the waste gas dissolving tank (13) are communicated by the heat exchange water recycling pipe (416), and the water pump (417) is connected to the water inlet end of the heat exchange water recycling pipe (416).

5. The apparatus for treating a waste liquid containing nitric acid according to claim 4, characterized by: The solid-liquid separation unit (2) further comprises a filter residue collecting tank (22), a filtrate collecting tank (23) and a filter press (24), the filter residue collecting tank (22) and the filtrate collecting tank (23) are both tank-like bodies provided with a sealing cover at the top, the filter residue collecting tank (22) is arranged side by side with the filtrate collecting tank (23), the neutralization and precipitation tank (21), the filter press (24) and the filter residue collecting tank (22) are sequentially arranged from top to bottom, the neutralization and precipitation tank (21) is a cavity tank body with a conical lower part, provided with a sealing cover at the top, the bottom of the neutralization and precipitation tank (21) is provided with an outlet with a blowdown valve (26), which is communicated with the feed inlet of the filter press (24), the filter residue outlet of the filter press (24) is communicated with the filter residue collecting tank (22), and the filtrate outlet of the filter press (24) is communicated with the filtrate collecting tank (23) through a filtrate discharge pipe (418).

6. The apparatus for treating a waste liquid containing nitric acid according to claim 5, characterized by: The first heat exchange pipe (25) is a spiral heat conducting pipe, which is fixedly connected to the inner wall of the neutralization and precipitation tank (21), the cold water input pipe (405) is connected to the inlet end of the first heat exchange pipe (25), and the first heat exchange pipe (25) is communicated with the second heat exchange pipe (14) through a heat exchange water conveying pipe (414).

7. The apparatus for treating a waste liquid containing nitric acid according to claim 6, characterized by: The medicament feeding pipe (404) is arranged at the upper part of the neutralization and precipitation tank (21), and the outlet end thereof is arranged in the neutralization and precipitation tank (21), the neutralization and precipitation tank (21) is communicated with the pre-tank (11) through a waste liquid conveying pipe (402), the first sewage pump (403) is connected to the inlet end of the waste liquid conveying pipe (402) and arranged in the pre-tank (11), the neutralization and precipitation tank (21) is communicated with the filtrate collecting tank (23) through a filtrate conveying pipe (419), and the third sewage pump (420) is connected to the inlet end of the filtrate conveying pipe (419) and arranged in the filtrate collecting tank (23).

8. The apparatus for treating a waste liquid containing nitric acid according to claim 7, characterized by: The evaporation crystallization unit (3) further comprises a separation liquid collecting tank (31), the separation liquid collecting tank (31) is a tank-like body provided with a sealing cover at the top, the separation liquid collecting tank (31) is communicated with the neutralization and precipitation tank (21) through a separation liquid discharge pipe (406), the inlet end of the separation liquid discharge pipe (406) is arranged at the middle part of the neutralization and precipitation tank (21) and is higher than the top surface of the separation liquid collecting tank (31).

9. The apparatus for treating a waste liquid containing nitric acid according to claim 8, characterized by: The separation liquid collecting tank (31) is communicated with the feed inlet of the evaporation crystallizer (32) through a separation liquid conveying pipe (407), the second sewage pump (408) is connected to the inlet end of the separation liquid conveying pipe (407) and arranged in the separation liquid collecting tank (31), the condensate water outlet of the evaporation crystallizer (32) is communicated with the waste gas dissolving tank (13) through a condensate water discharge pipe (409), and the pipeline pump (410) is connected to the condensate water discharge pipe (409).

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