CN110075679B - Waste gas treatment system and method for nitric acid stripping and hanging rack of circuit board - Google Patents

Waste gas treatment system and method for nitric acid stripping and hanging rack of circuit board Download PDF

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CN110075679B
CN110075679B CN201910389124.6A CN201910389124A CN110075679B CN 110075679 B CN110075679 B CN 110075679B CN 201910389124 A CN201910389124 A CN 201910389124A CN 110075679 B CN110075679 B CN 110075679B
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nitric acid
washing tower
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CN110075679A (en
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王博
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Chaoying Electronic Circuit Co ltd
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Dynamic Electronics Huangshi Co ltd
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/46—Removing components of defined structure
    • B01D53/54—Nitrogen compounds
    • B01D53/56—Nitrogen oxides
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/73—After-treatment of removed components
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/75—Multi-step processes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/77—Liquid phase processes
    • B01D53/78—Liquid phase processes with gas-liquid contact
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/02—Other waste gases

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  • Chemical & Material Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
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Abstract

The invention provides a waste gas treatment system, namely a method, for a nitric acid stripping rack of a circuit board, wherein the system comprises a nitric acid stripping tank, an adding device for adding a nitric acid volatilization inhibitor into the nitric acid stripping tank, and a primary oxidation washing device, a secondary reduction washing device, a tertiary neutralization washing device and a discharging device which are sequentially communicated; the nitric acid volatilization inhibitor comprises 5 to 15 weight percent of sulfonic acid, 5 to 15 weight percent of ferric nitrate, 0.1 to 0.5 weight percent of formaldehyde solution, 0.3 to 0.7 weight percent of benzotriazole and 0.1 to 1 weight percent of PEG; the sulfonic acid is one or two of sulfamic acid and alkyl sulfonic acid; the PEG is one or more of PEG 200-PEG 6000. The invention adopts the nitric acid volatilization inhibitor with special proportion, reduces NOXThe total amount of the generated waste gas is reduced, the load of waste gas treatment facilities is reduced, the total amount of the emission of waste gas pollution factors is reduced, and the purpose of emission reduction is achieved.

Description

Waste gas treatment system and method for nitric acid stripping and hanging rack of circuit board
Technical Field
The invention relates to the technical field of waste gas treatment of a nitric acid stripping and hanging rack of an electroplating line in the circuit board industry, in particular to a waste gas treatment system and method of a nitric acid stripping and hanging rack of a circuit board.
Background
The waste gas from nitric acid stripping rack in circuit board factory is usually absorbed by alkali solution, oxidation, reduction and absorption, … … and so on. However, these methods have disadvantages, and the rack stripping process in the circuit board factory is not a continuous process, and a large amount of NO is generated in the initial stage of the reaction between nitric acid and copperXIf the treatment is not timely or proper, a large amount of yellow smoke is generated.
(1) Alkali liquor absorption method:
NO+NO2+Na2CO3＝2NaNO2+CO2
2NO2+Na2CO3＝NaNO2+NaNO3+CO2
the disadvantages are as follows: when NO is in the exhaust gasXAt lower concentrations, NO2The oxidation process is slow, the absorption effect is influenced, the equipment required by the method is huge, and the accuracy of treatment is difficult to ensure.
(2) Oxidation absorption method:
2NO+O2＝NO2
the disadvantages are as follows: the commonly used solutions include hydrogen peroxide, concentrated sulfuric acid, potassium permanganate and the like, but the solvents are very difficult to be widely applied in industry because the solvents are expensive and recovery equipment is required.
(3) Reduction and absorption:
NO in nitric acid tail gas by using reducing agentXReduction to harmless N2As the reducing agent, ammonium sulfite, sodium sulfite, urea and the like are usually used.
NO+NO2＝N2O3
N2O3+H2O＝2HNO2
(NH2)2CO+2HNO2＝CO2+2N2+3H2O
The disadvantages are as follows: the absorption process is slow, and the nitrogen oxides in the tail gas are still high. Since many of the reducing agents contain nitrogen, the total amount of nitrogen in the discharged wastewater is increased, and the load of the wastewater treatment facility is increased.
(4) The extended absorption method:
one or more washing towers are added in series on the basis of the original waste gas washing tower, so that the oxidation space of tail gas is increased, and NO is prolonged2The absorption time of (2).
2NO+O2＝NO2
3NO2+H2O＝2HNO3+NO
The disadvantages are as follows: the absorption effect is not obvious, the emission requirement cannot be met, the emission is unstable, and yellow smoke is generated sometimes.
(5) An adsorption method:
the disadvantages are as follows: the adsorbent is costly and often requires equipment shut down for replacement.
(6) A catalytic reduction method:
the disadvantages are as follows: other constituents of the exhaust gases, e.g. oxygen, H2O and sulfuric acid mist influence the catalyst effect, and if the amount of free oxygen is too large, only decolorization (NO) can be performed2Reduced to NO) and NO elimination of NO is achieved2The purpose of (1).
The application number is CN201610738558.9, and the name is 'a method for treating high-concentration nitrate wastewater', and the specific method comprises the following steps: at normal temperature and normal pressureAdding zinc powder and sulfamic acid into high-concentration nitrate radical wastewater, wherein the ratio of nitrate radical: zinc powder: the molar ratio of sulfamic acid is 1: 1-5: 1-5, dividing the zinc powder and the sulfamic acid into a plurality of equal parts, adding the medicament once every five minutes, firstly adding the sulfamic acid, then adding the zinc powder, adding the zinc powder alternately after two hours, and reacting for 2-5 hours after the addition. Compared with the prior art, the reagent for treating the wastewater is cheap and convenient to purchase, NO wastewater treatment equipment is not required to be additionally purchased, and NO in the wastewaterXThe initial concentration of (1) is in the range of 5000-50000mg/L, and NO in the wastewater treated by the methodXThe concentration is less than or equal to 15mg/L, and the product meets the NO standard of copper and nickel cobalt industrial pollutant discharge StandardXDirect emission standard of (1). This document contrasts with the disclosure that "sulfamic acid can be used as a nitric acid volatility inhibitor to treat nitrate-containing wastewater".
However, NO in nitric acid stripping and hanging groove of current circuit board factoryXThe concentration of 220000 mg/L-460000 mg/L is far more than that of 50000mg/L in the patent, so that the treatment effect of separately adding sulfamic acid is poor, and the speed and the effect of the nitric acid nitrate rack are influenced if the sulfamic acid is excessively added. And if zinc powder is added, the amount of nitric acid is consumed, and zinc ions remain on the hanger and are carried into the plating tank to pollute the plating tank solution.
The above waste gas treatment processes all have various disadvantages, and for the circuit board industry, a safe, stable and low-cost waste gas treatment system and method are urgently needed to solve the practical difficulties.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a waste gas treatment system and a waste gas treatment method for a nitric acid stripping and hanging rack of a circuit board2Total efficiency and NO ofXThe total removal efficiency of; the method adopts nitric acid volatilization inhibitor with special ratio, and reduces NOXThe total amount of the generated waste gas is reduced, the load of waste gas treatment facilities is reduced, the total amount of the emission of waste gas pollution factors is reduced, the purpose of emission reduction is achieved, and the electroplating bath solution is not polluted.
The invention is realized by the following steps:
the invention aims to provide a waste gas treatment system for a nitric acid stripping and hanging rack of a circuit board, which comprises a nitric acid stripping and hanging tank for placing the nitric acid stripping and hanging rack of the circuit board, an adding device for adding a nitric acid volatilization inhibitor into the nitric acid stripping and hanging tank, and a primary oxidation washing device, a secondary reduction washing device, a tertiary neutralization washing device and a discharging device which are sequentially communicated;
the primary oxidation washing device comprises a primary connecting pipe, a primary oxygen supplementing mechanism, a primary washing tower and a primary medicine adding mechanism, wherein the upper part of the nitric acid stripping groove is communicated with a gas inlet of the primary washing tower through the primary connecting pipe, the primary oxygen supplementing mechanism is arranged on the primary connecting pipe, and the primary medicine adding mechanism is communicated with a liquid inlet of the primary washing tower;
the second-stage reduction washing device comprises a second-stage connecting pipe, a second-stage oxygen supplementing mechanism, a second-stage washing tower and a second-stage medicine adding mechanism, wherein a gas outlet of the first-stage washing tower is communicated with a gas inlet of the second-stage washing tower through the second-stage connecting pipe, the second-stage oxygen supplementing mechanism is arranged on the second-stage connecting pipe, and the second-stage medicine adding mechanism is communicated with a liquid inlet of the second-stage washing tower;
the three-stage neutralization and washing device comprises a three-stage connecting pipe, a three-stage oxygen supplementing mechanism, a three-stage washing tower and a three-stage medicine adding mechanism, wherein a gas outlet of the two-stage washing tower is communicated with a gas inlet of the three-stage washing tower through the three-stage connecting pipe, the three-stage oxygen supplementing mechanism is arranged on the three-stage connecting pipe, and the three-stage medicine adding mechanism is communicated with a liquid inlet of the three-stage washing tower;
and the discharge device is communicated with a gas outlet of the third-stage washing tower.
The invention also aims to provide a method for treating waste gas of a nitric acid stripping rack of a circuit board by adopting the system, which comprises the following steps:
s1, adding a nitric acid volatilization inhibitor into the nitric acid stripping groove through a nitric acid volatilization inhibitor adding device, wherein the concentration of nitric acid in the nitric acid stripping groove is 40-45%; the concentration of the nitric acid volatilization inhibitor is 90-99%, and the addition amount is 25-100L/day; the nitric acid volatilization inhibitor comprises 5 to 15 weight percent of sulfonic acid, 5 to 15 weight percent of ferric nitrate, 0.1 to 0.5 weight percent of formaldehyde solution, 0.3 to 0.7 weight percent of benzotriazole and 0.1 to 1 weight percent of PEG; wherein the sulfonic acid is one or two of sulfamic acid and alkyl sulfonic acid; the PEG is one or more of PEG 200-PEG 6000;
s2, opening a primary oxygen supplementing mechanism to add air volume into the primary washing tower; opening a primary dosing mechanism to add alkaline oxidant liquid medicine into the primary washing tower for washing;
s3, opening a secondary oxygen supplementing mechanism to add air volume into the secondary washing tower; opening a secondary dosing mechanism to add alkaline reducing agent liquid medicine into the secondary washing tower for washing;
s4, opening a three-stage oxygen supplementing mechanism to add air volume into the three-stage washing tower; opening a three-stage dosing mechanism to add alkaline reducing agent liquid medicine into the three-stage washing tower for washing;
and S5, opening the discharging device, and discharging the waste gas which reaches the standard after being treated by the three-stage washing tower at high altitude through the discharging device.
The invention has the following beneficial effects:
1. the invention provides a waste gas treatment system for a nitric acid stripping and hanging rack of a circuit board, which comprises a primary oxidation washing device, a secondary reduction washing device and a tertiary neutralization washing device, wherein the waste gas is subjected to multi-stage air supplement and dosing, oxidation and reduction are carried out, and the oxidation of NO into NO is improved2Total efficiency and NO ofXThe overall removal efficiency of.
2. According to the method for treating waste gas generated by stripping nitric acid from the rack of the circuit board, provided by the invention, the nitric acid volatilization inhibitor is adopted as a multi-component medicament which is subjected to multiple tests and preparation verification, the liquid medicine property is stable, and NO is delayedXWaste gas is generated, and the effect of stably stripping and hanging the rack has obvious effect; meanwhile, the load of waste gas treatment facilities is reduced, the total emission amount of waste gas pollution factors is reduced, and the purpose of emission reduction is achieved.
Drawings
FIG. 1 is a schematic structural diagram of a waste gas treatment system of a nitric acid stripping and hanging rack of a circuit board provided by the invention;
FIG. 2 is a schematic control diagram of a power device of a waste gas treatment system of a nitric acid stripping and hanging rack of a circuit board provided by the invention;
FIG. 3 is a flow chart of a waste gas treatment method for a nitric acid stripping rack of a circuit board provided by the invention;
wherein 1, stripping a hanging groove by nitric acid; 2. an adding device; 21. a nitric acid inhibitor holding tank; 22. a liquid medicine delivery pipe; 23. a nitric acid inhibitor dosing pump; 3. a primary oxidation washing device; 31. a primary connecting pipe; 32. a first-stage oxygen supplementing mechanism; 33. a first-stage washing tower; 34. a first-level dosing mechanism; 341. a first alkali liquor dosing barrel; 342. a first alkali liquor dosing pump; 343. an oxidizing liquid dosing barrel; 344. an oxidizing liquid dosing pump; 345. a first pH controller; 346. a first ORP controller; 4. a secondary reduction washing device; 41. a secondary connecting pipe; 42. a secondary oxygen supplement mechanism; 43. a secondary washing tower; 44. a secondary dosing mechanism; 441. a second alkali liquor dosing barrel; 442. a second alkali liquor dosing pump; 443. a reducing liquid adding barrel; 444. a reducing liquid dosing pump; 445. a second pH controller; 446. a second ORP controller; 5. a third-stage neutralization washing device; 51. a third-stage connecting pipe; 52. a third-stage oxygen supplementing mechanism; 53. a third stage washing tower; 54. a third-level dosing mechanism; 541. a third alkali liquor dosing barrel; 542. a third alkali liquor dosing pump; 543. a neutralization washing liquid adding barrel; 544. a neutralization washing liquid dosing pump; 545. a third pH controller; 546. a third ORP controller; 6. a discharge device; 61. an exhaust pipe; 62. an exhaust valve; 63. an exhaust fan.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
As shown in fig. 1, the present embodiment provides a waste gas treatment system for a nitric acid stripping rack of a circuit board, which includes a nitric acid stripping tank 1 for placing the nitric acid stripping rack of the circuit board, an adding device 2 for adding a nitric acid volatilization inhibitor into the nitric acid stripping tank 1, and a primary oxidation washing device 3, a secondary reduction washing device 4, a tertiary neutralization washing device 5, and a discharging device 6, which are sequentially communicated;
the nitric acid volatilization inhibitor arranged in the adding device 2 comprises 5-15 percent of sulfonic acid, 5-15 percent of ferric nitrate, 0.1-0.5 percent of formaldehyde solution, 0.3-0.7 percent of benzotriazole and 0.1-1 percent of PEG according to weight percentage; wherein the sulfonic acid is one or two of sulfamic acid and alkyl sulfonic acid; the PEG is one or more of PEG 200-PEG 6000;
wherein, the components are all analytical pure medicines, and the purity is 99.9%. The weight percentage is that after the components are mixed uniformly, the sulfonic acid (accounting for 5-15% of the concentration of the mixed liquid medicine), the ferric nitrate (accounting for 5-15% of the concentration of the mixed liquid medicine), the formaldehyde solution (accounting for 0.1-0.5% of the concentration of the mixed liquid medicine), the BTA (benzotriazole, accounting for 0.3-0.7% of the concentration of the mixed liquid medicine) and the PEG 200-PEG 6000 (accounting for 0.1-1% of the concentration of the mixed liquid medicine) are mixed uniformly.
The primary oxidation washing device 3 comprises a primary connecting pipe 31, a primary oxygen supplementing mechanism 32, a primary washing tower 33 and a primary medicine adding mechanism 34, wherein the upper part of the nitric acid stripping groove 1 is communicated with a gas inlet of the primary washing tower 33 through the primary connecting pipe 32, the primary oxygen supplementing mechanism 32 is arranged on the primary connecting pipe 31, and the primary medicine adding mechanism 34 is communicated with a liquid inlet of the primary washing tower 33;
the secondary reduction washing device 4 comprises a secondary connecting pipe 41, a secondary oxygen supplementing mechanism 42, a secondary washing tower 43 and a secondary medicine adding mechanism 44, wherein a gas outlet of the primary washing tower 33 is communicated with a gas inlet of the secondary washing tower 43 through the secondary connecting pipe 41, the secondary oxygen supplementing mechanism 42 is arranged on the secondary connecting pipe 41, and the secondary medicine adding mechanism 44 is communicated with a liquid inlet of the secondary washing tower 43;
the three-stage neutralization and washing device 5 comprises a three-stage connecting pipe 51, a three-stage oxygen supplementing mechanism 52, a three-stage washing tower 53 and a three-stage medicine adding mechanism 54, wherein a gas outlet of the second-stage washing tower 43 is communicated with a gas inlet of the third-stage washing tower 53 through the three-stage connecting pipe 51, the three-stage oxygen supplementing mechanism 52 is arranged on the three-stage connecting pipe 51, and the three-stage medicine adding mechanisms 54 are all communicated with a liquid inlet of the third-stage washing tower 53;
the discharging device 6 is communicated with the gas outlet of the tertiary washing tower 53.
This embodiment provides a rack exhaust treatment system is shelled to circuit board nitric acid, at first nitric acid shells and hangs the interior reaction of taking place of groove 1: 3Cu +8HNO3＝3Cu(NO3)2+2NO (gas) +4H2O, adding a nitric acid volatilization inhibitor into the nitric acid stripping and hanging groove 1 through the adding device 2, wherein the nitric acid volatilization inhibitor is adopted as a multi-component medicament which is prepared and verified through multiple tests, the liquid medicine property is stable, and NO is delayedXWaste gas is generated, and the effect of stably stripping and hanging the rack has obvious effect; meanwhile, the load of waste gas treatment facilities is reduced, the total emission amount of waste gas pollution factors is reduced, and the purpose of emission reduction is achieved;
then the volatilized nitrogen oxides enter a primary oxidation washing device 3: the nitrogen oxides enter the bottom of the primary washing tower 33, and the unreacted NO part is oxidized into NO by the primary oxygen supply mechanism 322Most of NO is generated after NO is oxidized2The mixed gas enters the upper part of the first-stage washing tower 33, the first-stage dosing mechanism 34 inputs the oxidizing liquid and the alkali liquor into the first-stage washing tower 33, and the mixed gas further generates oxidation reaction and is neutralized with the alkali liquor;
then the mixed gas enters a secondary oxidation washing device 4: unreacted NOXThe NO still contained in the solution is further oxidized into NO by a secondary oxygen supply mechanism 422The second-stage dosing mechanism 44 feeds the reagents (lye and sodium thiosulfate reagents) to the second-stage scrubber 43 for NO reduction by the reducing agent under alkaline conditionsXReduction to harmless N2；
Then the mixed gas enters a three-stage oxidation washing device 5 for further oxidation washing;
and finally, the treated waste gas is exhausted from the gas outlet of the third-stage washing tower 53 in the high altitude by inducing air through an exhaust device.
In summary, the invention adopts the first-stage oxidation washing device 3, the second-stage reduction washing device 4 and the third-stage neutralization washing device 5 to carry out multi-stage air supplement and medicine addition on the waste gas for oxidation and reduction, thereby improving the oxidation of NO into NO2Total efficiency and NO ofXThe overall removal efficiency of.
The ratio of the diameter of the primary oxygen supplementing mechanism to the diameter of the air extraction main air pipe is 1/20-1/10; the diameter of the outlet air pipe of the secondary reduction washing device is 1.1-1.3 times of that of the outlet air pipe of the primary oxidation washing device; the ratio of the diameter of the third-stage oxygen supplementing mechanism to the diameter of the air extraction main air pipe is 1/30-1/20;
wherein, the diameter of the first-stage oxygen supplying mechanism in the invention is the diameter of the first-stage connecting pipe 31 in fig. 1; the diameter of the outlet air pipe of the primary oxidation washing device is the diameter of the secondary connecting pipe 41 in the figure 1; the outlet air pipe of the secondary reduction washing device is the tertiary connecting pipe 51 in fig. 1; the diameter of the third-stage oxygen supplementing mechanism is the diameter of the third-stage connecting pipe 51; the main air exhaust pipe is a main pipeline which is positioned above the nitric acid stripping and hanging groove 1 and in front of the primary connecting pipe 31. The same applies below.
Preferably, as shown in fig. 1, the adding device 2 includes a nitric acid inhibitor storage tank 21, a liquid medicine delivery pipe 22, and a nitric acid inhibitor quantitative pump 23, the nitric acid inhibitor storage tank 21 is communicated with the nitric acid stripping tank 1 through the liquid medicine delivery pipe 22, and the nitric acid inhibitor quantitative pump 23 is disposed on the liquid medicine delivery pipe 22.
Preferably, as shown in fig. 1, each of the first-stage washing tower 33, the second-stage washing tower 43, and the third-stage washing tower 53 includes a collecting tank, a packing layer, a spraying layer, and a defogging layer, which are sequentially disposed from bottom to top; the spraying layer of the primary washing tower is connected with the primary dosing mechanism; the spraying layer of the secondary washing tower is connected with the secondary dosing mechanism; and the spraying layer of the three-stage washing tower is connected with the three-stage dosing mechanism.
Preferably, as shown in fig. 1, the first-stage washing tower 33, the second-stage washing tower 43, and the third-stage washing tower 53 are all provided with a circulation pump, and the collecting tanks of the first-stage washing tower, the second-stage washing tower, and the third-stage washing tower are respectively communicated with the spraying layer through the provided circulation pumps. And the washing liquid in the collecting tank is recycled through the circulating pump.
Preferably, as shown in fig. 1, the primary oxygen supplement mechanism 32, the secondary oxygen supplement mechanism 42 and the tertiary oxygen supplement mechanism 52 are each a set of adjustable dampers.
Preferably, as shown in fig. 1, the discharging device 6 comprises an exhaust pipe 61, an exhaust valve 62 and an exhaust fan 63, the gas outlet of the three-stage washing tower 53 is connected with the exhaust fan 63 through the exhaust pipe 61, and the exhaust valve 62 is arranged on the exhaust pipe 61. The treated waste gas can meet the requirements of 'discharge standard of electroplating pollutants', and is finally discharged at high altitude by inducing air through an exhaust fan 63.
Preferably, as shown in fig. 1-2, the primary medicine adding mechanism 34 includes a first alkali liquor adding barrel 341, a first alkali liquor adding pump 342, an oxidizing liquid adding barrel 343, an oxidizing liquid adding pump 344, a first pH controller 345, and a first ORP controller 346, the first alkali liquor adding barrel 341 communicates with the liquid inlet of the primary washing tower 33 (enters the spraying layer of the primary washing tower 33) through the first alkali liquor adding pump 342, and the oxidizing liquid adding barrel 343 communicates with the liquid inlet of the primary washing tower (enters the spraying layer of the primary washing tower 33) through the oxidizing liquid adding pump 344;
the first alkali liquor dosing pump 342 is electrically connected with the first pH controller 345, the oxidizing liquor dosing pump 344 is electrically connected with the first ORP controller 346, alkali liquor is arranged in the first alkali liquor dosing barrel, and the alkali liquor comprises Na2CO3At least one of NaOH; NaCLO and NaCLO are arranged in the oxidizing solution dosing barrel2、NaCLO3At least one of (1). The pH value control range of the alkali liquor is 9-11; the ORP value control range is 20-200 mv; the reaction time of the waste gas and the alkaline oxidant liquid is 1.5-5 seconds; the alkaline oxidant liquid comprises the alkaline liquor and the oxidizing liquid is filled in a medicine adding barrel and is internally provided with NaCLO and NaCLO2、NaCLO3At least one of (1).
Preferably, as shown in fig. 1-2, the secondary dosing mechanism 44 includes a second alkaline solution dosing barrel 441, a second alkaline solution dosing pump 442, a reducing solution dosing barrel 443, a reducing solution dosing pump 444, a second pH controller 445, and a second ORP controller 446, the second alkaline solution dosing barrel 441 is communicated with the liquid inlet of the secondary washing tower 43 (into the spray layer of the secondary washing tower 43) through the second alkaline solution dosing pump 442, and the reducing solution dosing barrel 443 is communicated with the liquid inlet of the secondary washing tower 43 (into the spray layer of the secondary washing tower 43) through the reducing solution dosing pump 444; the heat generation volume of the second-stage washing tower 43 is 2 to 3 times of the volume of the first-stage washing tower 33.
The second alkaline solution dosing pump 442 is electrically connected with the second pH controller 445, the reducing solution dosing pump 444 is electrically connected with the second ORP controller 446, an alkaline solution is arranged in the second alkaline solution dosing barrel, and the alkaline solution comprises Na2CO3At least one of NaOH; na is arranged in the reducing liquid medicine adding barrel2S2O3. The second pH controller 445 controls the pH value of the alkali liquor in the second alkali liquor dosing barrel to be within 9-11, and controls the ORP value to be within-160-100 mv; the concentration of the sodium thiosulfate liquid medicine is controlled to be 2-10 percent; the reaction time of the waste gas and the alkaline reducing agent liquid medicine is 4-15 seconds; the alkaline reducing agent liquid comprises the alkaline solution (including Na)2CO3At least one of NaOH) and Na arranged in the reducing solution dosing barrel2S2O3。
Preferably, as shown in fig. 1-2, the third medicine adding mechanism 54 includes a third alkali liquor adding barrel 541, a third alkali liquor adding pump 542, a neutralized washing liquor adding barrel 543, a neutralized washing liquor adding pump 544, a third pH controller 545 and a third ORP controller 546, the third alkali liquor adding barrel 541 is communicated with the liquid inlet of the third washing tower 53 (entering the spraying layer of the third washing tower 53) through the third alkali liquor adding pump 542, and the neutralized washing liquor adding barrel 543 is communicated with the liquid inlet of the third washing tower 53 (entering the spraying layer of the third washing tower 53) through the neutralized washing liquor adding pump 544;
the third alkali liquor dosing pump 542 is electrically connected with the third pH controller 545,the neutralization washing liquid dosing pump 543 is electrically connected with the third ORP controller 546, an alkali liquid is arranged in the third alkali liquid dosing barrel, and the alkali liquid comprises Na2CO3At least one of NaOH; na is arranged in the neutralization washing liquid medicine adding barrel2S2O3. The third pH controller 545 controls the pH value of the alkali liquor within a range of 9-12, and controls the ORP value within a range of-160 mv to-100 mv; the concentration of the sodium thiosulfate liquid medicine is controlled to be 2-10 percent; the reaction time of the waste gas and the alkaline reducing agent liquid is 4-5 seconds. The alkaline reducing agent liquid comprises the alkaline solution (including Na)2CO3At least one of NaOH) and Na arranged in the neutralization washing liquid feeding barrel2S2O3。
As can be seen from fig. 2, the main power switch of the present invention is controlled by PLC, 220V 100A, mitsubishi brand no-fuse circuit breaker model: NFC60-SMXA (20A-40A); power main power switch 380V 250A, mitsubishi brand no fuse circuit breaker model: NFC 250-SMXA. Converter TECO brand, model: 3pH value is-440V-37.0 KW (the adjusting range is 25-50 HZ). The model of the first pH controller 345, the first ORP controller 346, the second pH controller 445, the second ORP controller 446, the third pH controller 545 and the third ORP controller 546 is the Shangti pc 350; except that the probes for first ORP controller 346, second ORP controller 446 and third ORP controller 546 are different.
When the first-level dosing mechanism 34, the second-level dosing mechanism 44 and the third-level dosing mechanism 54 are used for dosing, the total nitrogen amount discharged to the wastewater treatment system by the waste gas system is greatly reduced by adopting the oxidant and the reducing agent which do not contain nitrogen, so that the load of the wastewater treatment facility can be reduced, the wastewater treatment system is ensured to stably meet the requirements of 'discharge standard of electroplating pollutants' table 3, and the long-term operation cost is lower.
Example 2
As shown in fig. 1 to 3, the present embodiment provides a waste gas treatment method for a nitric acid stripping rack of a circuit board, including:
first, a nitric acid volatilization inhibitor was added to a 4000L nitric acid stripping tank 1 by an addition device 2. Specifically, the method comprises the following steps:
the concentration of nitric acid in the nitric acid tank is 40%, the concentration of the added nitric acid volatilization inhibitor is 90%, and the addition amount is 25L/day. The addition is carried out in a manner of automatically adding the average addition amount per minute. Thus, the concentration of the liquid medicine can be kept stable, and the treatment effect is optimal. The nitric acid volatilization inhibitor comprises 5 weight percent of alkyl sulfonic acid, 15 weight percent of ferric nitrate, 0.1 weight percent of formaldehyde solution, 0.7 weight percent of benzotriazole and 0.1 weight percent of PEG 200-PEG 6000;
opening a first-stage oxygen supplementing mechanism to add air quantity into the first-stage washing tower; opening the first-stage dosing mechanism to add liquid medicine into the first-stage washing tower for washing. Specifically, the method comprises the following steps:
1. the volatilized nitrogen oxide contains NO and NO2Since NO is insoluble in water and not easily absorbed, it is based on 3Cu +8HNO3＝3Cu(NO3)2+2NO (gas) +4H2O, partial oxidation of NO formed by the reaction to NO2The unreacted NO is further oxidized to NO by the primary oxygen supplying means 322The primary oxygen supply mechanism 32 can add air volume through an air valve. The ratio of the air supply quantity of the primary oxygen supply mechanism 32 to the air quantity of the air extraction main air pipe is 1/10. The mixed gas enters the primary scrubber 33.
2. NO oxidation to generate NO2The mixed gas enters the primary washing tower 33 and then undergoes further oxidation reaction, and is neutralized with an alkaline oxidizing agent. Wherein: the pH value control range is 9, and the ORP value control range is 80 mv. The waste gas and the first alkali solution are added with the alkali solution in the barrel, and the oxidation solution is added with the liquid medicine (NaCLO ) in the barrel2、NaCLO3At least one of) was 1.5 seconds; the washing liquid is circulated by a circulating spray pump.
Thirdly, opening a secondary oxygen supplementing mechanism to add air quantity into the secondary washing tower; opening a second-stage dosing mechanism to add liquid medicine into a second-stage washing tower for washing, specifically:
1. unreacted NOXThe NO still contained in the solution is further oxidized into NO by a secondary oxygen supply mechanism 422The secondary oxygen supplement mechanism 42 can add air volume through an air valve. Air supply and air extraction main air pipe of secondary oxygen supply mechanism 42The air volume ratio of (2) is 1/20. The mixed gas enters the secondary scrubber 43.
2. In the second washing tower 43, the added agents include an alkaline agent in the second alkaline liquid adding barrel and sodium thiosulfate in the reducing liquid adding barrel, so that NO is added by the reducing agent under alkaline conditionsXReduction to harmless N2Wherein: the pH value control range of the alkaline medicament is 9; the concentration of the sodium thiosulfate liquid medicine is controlled to be 5 percent, and the ORP value is controlled to be within-100 mv; the reaction time of the waste gas with the alkaline agent and the sodium thiosulfate was 4 seconds. At this stage, the reaction time becomes longer because the feed gas concentration is reduced. Because the second-stage oxygen supplementing mechanism 42 increases the total amount of the waste gas, the volume of the corresponding second-stage washing tower 43 is 2 times of that of the first-stage washing tower 33, and the diameter of an outlet air pipe of the second-stage washing tower 43 is 1.1 times of that of the outlet air pipe of the first-stage washing tower 33. The washing liquid is circulated by a circulating spray pump.
Thirdly, opening a third-stage oxygen supplementing mechanism to add air quantity into the third-stage washing tower; opening a three-level dosing mechanism to add liquid medicine into a three-level washing tower for washing, specifically:
1. if there is NO remaining unreacted NOXThe NO still contained in the carbon dioxide is further oxidized into NO by a three-stage oxygen supplement mechanism 522The tertiary oxygen supply mechanism 52 can add air volume through an air valve. The ratio of the air supply quantity of the third-stage oxygen supply mechanism 52 to the air quantity of the air extraction main air pipe is 1/30.
2. In the three-stage washing tower 53, the added agents include alkaline agent in the third alkali liquor dosing barrel and sodium thiosulfate in the neutralized washing liquor dosing barrel, aiming at NO in alkaline condition by the reducing agentXReduction to harmless N2Simultaneously, the alkalinity and the pH value of the washing liquid medicine are improved, and the low-concentration NO is improvedXThe absorption efficiency of the gas. The concentration of the sodium thiosulfate is controlled to be 2 percent, the pH value control range is about 9, the ORP value control range is about-110 mv, and the reaction time of the waste gas, the alkaline agent in the third alkali liquor dosing barrel and the sodium thiosulfate in the neutralization washing liquor dosing barrel is 4 seconds. The washing liquid is circulated by a circulating spray pump.
3. Through the reaction process of the process, the treated waste gas can meet the requirements of the discharge standard of electroplating pollutants, and is finally discharged in the high air by inducing air through the exhaust fan.
Example 3
As shown in fig. 1 to 3, the present embodiment provides a waste gas treatment method for a nitric acid stripping rack of a circuit board, including:
first, a nitric acid volatilization inhibitor was added to a 4000L nitric acid stripping tank 1 by an addition device 2. Specifically, the method comprises the following steps:
the concentration of nitric acid in the nitric acid tank is 43 percent, the concentration of the added nitric acid volatilization inhibitor is 93 percent, and the adding amount is 50L/day. The addition is carried out in a manner of automatically adding the average addition amount per minute. Thus, the concentration of the liquid medicine can be kept stable, and the treatment effect is optimal. The nitric acid volatilization inhibitor comprises 15 percent of sulfamic acid (or a mixture of 15 percent of sulfamic acid and alkyl sulfonic acid), 5 percent of ferric nitrate, 0.5 percent of formaldehyde solution, 0.3 percent of benzotriazole and 1 percent of PEG 200-PEG 6000 in percentage by weight;
opening a first-stage oxygen supplementing mechanism to add air quantity into the first-stage washing tower; opening the first-stage dosing mechanism to add liquid medicine into the first-stage washing tower for washing. Specifically, the method comprises the following steps:
1. the volatilized nitrogen oxide contains NO and NO2Since NO is insoluble in water and not easily absorbed, it is based on 3Cu +8HNO3＝3Cu(NO3)2+2NO (gas) +4H2O, partial oxidation of NO formed by the reaction to NO2The unreacted NO is further oxidized to NO by the primary oxygen supplying means 322The primary oxygen supply mechanism 32 can add air volume through an air valve. The ratio of the air supply quantity of the primary oxygen supply mechanism 32 to the air quantity of the air extraction main air pipe is 1/5. The mixed gas enters the primary scrubber 33.
2. NO oxidation to generate NO2The mixed gas enters the primary washing tower 33 and then undergoes further oxidation reaction, and is neutralized with an alkaline oxidizing agent. Wherein: the pH value control range is 10, and the ORP value control range is 130 mv. The waste gas and the first alkali solution are added with the alkali solution in the barrel, and the oxidation solution is added with the liquid medicine (NaCLO ) in the barrel2、NaCLO3At least one of) was 3 seconds; washing liquid is passed throughAnd circulating by a circulating spray pump.
Thirdly, opening a secondary oxygen supplementing mechanism to add air quantity into the secondary washing tower; opening a second-stage dosing mechanism to add liquid medicine into a second-stage washing tower for washing, specifically:
1. unreacted NOXThe NO still contained in the solution is further oxidized into NO by a secondary oxygen supply mechanism 422The secondary oxygen supplement mechanism 42 can add air volume through an air valve. The ratio of the air supply quantity of the secondary oxygen supply mechanism 42 to the air quantity of the air extraction main air pipe is 1/15. The mixed gas enters the secondary scrubber 43.
2. In the second washing tower 43, the added agents include an alkaline agent in the second alkaline liquid adding barrel and sodium thiosulfate in the reducing liquid adding barrel, so that NO is added by the reducing agent under alkaline conditionsXReduction to harmless N2Wherein: the pH value control range of the alkaline medicament is 10.5; the concentration of the sodium thiosulfate liquid medicine is controlled to be 5 percent, and the ORP value is controlled to be in a range of-130 mv; the reaction time of the waste gas with the alkaline agent and the sodium thiosulfate is 8 seconds. At this stage, the reaction time becomes longer because the feed gas concentration is reduced. Because the second-stage oxygen supplementing mechanism 42 increases the total amount of the waste gas, the volume of the corresponding second-stage washing tower 43 is 2.5 times of that of the first-stage washing tower 33, and the diameter of the air pipe at the outlet of the second-stage washing tower 43 is 1.2 times of that of the air pipe at the outlet of the first-stage washing tower 33. The washing liquid is circulated by a circulating spray pump.
Thirdly, opening a third-stage oxygen supplementing mechanism to add air quantity into the third-stage washing tower; opening a three-level dosing mechanism to add liquid medicine into a three-level washing tower for washing, specifically:
1. if there is NO remaining unreacted NOXThe NO still contained in the carbon dioxide is further oxidized into NO by a three-stage oxygen supplement mechanism 522The tertiary oxygen supply mechanism 52 can add air volume through an air valve. The ratio of the air supply quantity of the third-stage oxygen supply mechanism 52 to the air quantity of the air extraction main air pipe is 1/25.
2. In the three-stage washing tower 53, the added agents include alkaline agent in the third alkali liquor dosing barrel and sodium thiosulfate in the neutralized washing liquor dosing barrel, aiming at NO in alkaline condition by the reducing agentXReduction to harmless N2While increasing the alkalinity of the washing liquidAnd pH value, increase of low concentration NOXThe absorption efficiency of the gas. The concentration of the sodium thiosulfate is controlled to be 10 percent, the pH value control range is 11, the ORP value control range is about-140 mv, and the reaction time of the waste gas, the alkaline agent in the third alkali liquor dosing barrel and the sodium thiosulfate in the neutralization washing liquor dosing barrel is 4.5 seconds. The washing liquid is circulated by a circulating spray pump.
3. Through the reaction process of the process, the treated waste gas can meet the requirements of the discharge standard of electroplating pollutants, and is finally discharged in the high air by inducing air through the exhaust fan.
Example 4
As shown in fig. 1 to 3, the present embodiment provides a waste gas treatment method for a nitric acid stripping rack of a circuit board, including:
first, a nitric acid volatilization inhibitor was added to a 4000L nitric acid stripping tank 1 by an addition device 2. Specifically, the method comprises the following steps:
the concentration of nitric acid in the nitric acid tank is 45%, the concentration of the added nitric acid volatilization inhibitor is 95%, and the addition amount is 100L/day. The addition is carried out in a manner of automatically adding the average addition amount per minute. Thus, the concentration of the liquid medicine can be kept stable, and the treatment effect is optimal. The nitric acid volatilization inhibitor comprises, by weight, 10% of sulfamic acid, 10% of ferric nitrate, 0.2% of formaldehyde solution, 0.5% of benzotriazole and 0.5% of PEG 200-PEG 6000;
opening a first-stage oxygen supplementing mechanism to add air quantity into the first-stage washing tower; opening the first-stage dosing mechanism to add liquid medicine into the first-stage washing tower for washing. Specifically, the method comprises the following steps:
1. the volatilized nitrogen oxide contains NO and NO2Since NO is insoluble in water and not easily absorbed, it is based on 3Cu +8HNO3＝3Cu(NO3)2+2NO (gas) +4H2O, partial oxidation of NO formed by the reaction to NO2The unreacted NO is further oxidized to NO by the primary oxygen supplying means 322The primary oxygen supply mechanism 32 can add air volume through an air valve. The ratio of the air supply quantity of the primary oxygen supply mechanism 32 to the air quantity of the air extraction main air pipe is 2/5. The mixed gas enters the primary scrubber 33.
2、NMost of O is oxidized to NO2The mixed gas enters the primary washing tower 33 and then undergoes further oxidation reaction, and is neutralized with an alkaline oxidizing agent. Wherein: the pH value control range is 11, and the ORP value control range is 180 mv. The waste gas and the first alkali solution are added with the alkali solution in the barrel, and the oxidation solution is added with the liquid medicine (NaCLO ) in the barrel2、NaCLO3At least one of) was 5 seconds; the washing liquid is circulated by a circulating spray pump.
Thirdly, opening a secondary oxygen supplementing mechanism to add air quantity into the secondary washing tower; opening a second-stage dosing mechanism to add liquid medicine into a second-stage washing tower for washing, specifically:
1. unreacted NOXThe NO still contained in the solution is further oxidized into NO by a secondary oxygen supply mechanism 422The secondary oxygen supplement mechanism 42 can add air volume through an air valve. The ratio of the air supply quantity of the secondary oxygen supply mechanism 42 to the air quantity of the air extraction main air pipe is 1/10. The mixed gas enters the secondary scrubber 43.
2. In the second washing tower 43, the added agents include an alkaline agent in the second alkaline liquid adding barrel and sodium thiosulfate in the reducing liquid adding barrel, so that NO is added by the reducing agent under alkaline conditionsXReduction to harmless N2Wherein: the pH value control range of the alkaline medicament is 11; the concentration of the sodium thiosulfate liquid medicine is controlled to be 5 percent, and the ORP value is controlled to be in the range of-150 mv; the reaction time of the waste gas with the alkaline agent and the sodium thiosulfate is 15 seconds. At this stage, the reaction time becomes longer because the feed gas concentration is reduced. Because the second-stage oxygen supplementing mechanism 42 increases the total amount of the waste gas, the volume of the corresponding second-stage washing tower 43 is 3 times of that of the first-stage washing tower 33, and the diameter of an outlet air pipe of the second-stage washing tower 43 is 1.3 times of that of the outlet air pipe of the first-stage washing tower 33. The washing liquid is circulated by a circulating spray pump.
Thirdly, opening a third-stage oxygen supplementing mechanism to add air quantity into the third-stage washing tower; opening a three-level dosing mechanism to add liquid medicine into a three-level washing tower for washing, specifically:
1. if there is NO remaining unreacted NOXThe NO still contained in the carbon dioxide is further oxidized into NO by a three-stage oxygen supplement mechanism 522The three-stage oxygen supplement mechanism 52 canTo add air volume through the damper. The ratio of the air supply quantity of the third-stage oxygen supply mechanism 52 to the air quantity of the air extraction main air pipe is 1/20.
2. In the three-stage washing tower 53, the added agents include alkaline agent in the third alkali liquor dosing barrel and sodium thiosulfate in the neutralized washing liquor dosing barrel, aiming at NO in alkaline condition by the reducing agentXReduction to harmless N2Simultaneously, the alkalinity and the pH value of the washing liquid medicine are improved, and the low-concentration NO is improvedXThe absorption efficiency of the gas. The concentration of the sodium thiosulfate is controlled to be 5 percent, the pH value control range is 12, the ORP value control range is about-160 mv, and the reaction time of the waste gas, the alkaline agent in the third alkali liquor dosing barrel and the sodium thiosulfate in the neutralization washing liquor dosing barrel is 5 seconds. The washing liquid is circulated by a circulating spray pump.
3. Through the reaction process of the process, the treated waste gas can meet the requirements of the discharge standard of electroplating pollutants, and is finally discharged in the high air by inducing air through the exhaust fan.
Comparative example 1
The comparative example is the same as example 4 except that sulfamic acid with a concentration of 90-99% is used as the nitric acid volatilization inhibitor.
Examples of the experiments
Statistics of exhaust ports NO corresponding to examples 2 to 4 and comparative example 1XThe concentration values are shown in Table 1.
TABLE 1
Item Concentration of inlet nitrogen oxides (mg/m)3) Concentration of nitrogen oxides at discharge outlet (mg/m)3) Removal efficiency
Example 2 sample 252 32 87％
Example 3 sample 337 38 89％
Example 4 sample 470 45 90％
Comparative example 1 sample 680 216 31.8％
Reference standard / 200 /
As can be seen from Table 1, the invention adopts the nitric acid volatilization inhibitor as the multi-component medicament which is verified by multiple tests, the liquid medicine has stable property, and the NO is delayedXWaste gas is generated, and the effect of stably stripping and hanging the rack has obvious effect; at the same time reduce NOXThe total amount of the generated waste gas is reduced, the load of waste gas treatment facilities is reduced, the total amount of the emission of waste gas pollution factors is reduced, and the purpose of emission reduction is achieved.
In conclusion, the invention adopts multi-stage oxidation and reduction processes, and optimizes the size and volume of each washing tower section according to the optimal designAdding different chemical agents (such as NaCLO or NaCLO)2Or NaCLO3And Na2S2O3) Set different ORP control ranges, improving the oxidation of NO to NO2Total efficiency and NO ofXThe total removal efficiency of; the wastewater treatment system is ensured to stably meet the requirements of 'electroplating pollutant discharge standard' in table 3, and the long-term operation cost is lower; simple process equipment, low equipment manufacturing cost, convenient operation, strong automatic control and low running cost.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims (9)

1. A waste gas treatment system for a nitric acid stripping rack of a circuit board is characterized by comprising a nitric acid stripping tank for placing the nitric acid stripping rack of the circuit board, an adding device for adding a nitric acid volatilization inhibitor into the nitric acid stripping tank, and a primary oxidation washing device, a secondary reduction washing device, a tertiary neutralization washing device and a discharging device which are sequentially communicated;
the adding device comprises a nitric acid inhibitor storage tank, a liquid medicine conveying pipe and a nitric acid inhibitor quantitative pump, the nitric acid inhibitor storage tank is communicated with the nitric acid stripping groove through the liquid medicine conveying pipe, and the nitric acid inhibitor quantitative pump is arranged on the liquid medicine conveying pipe;
the primary oxidation washing device comprises a primary connecting pipe, a primary oxygen supplementing mechanism, a primary washing tower and a primary medicine adding mechanism, wherein the upper part of the nitric acid stripping groove is communicated with a gas inlet of the primary washing tower through the primary connecting pipe, the primary oxygen supplementing mechanism is arranged on the primary connecting pipe, and the primary medicine adding mechanism is communicated with a liquid inlet of the primary washing tower;
the second-stage reduction washing device comprises a second-stage connecting pipe, a second-stage oxygen supplementing mechanism, a second-stage washing tower and a second-stage medicine adding mechanism, wherein a gas outlet of the first-stage washing tower is communicated with a gas inlet of the second-stage washing tower through the second-stage connecting pipe, the second-stage oxygen supplementing mechanism is arranged on the second-stage connecting pipe, and the second-stage medicine adding mechanism is communicated with a liquid inlet of the second-stage washing tower;
the three-stage neutralization and washing device comprises a three-stage connecting pipe, a three-stage oxygen supplementing mechanism, a three-stage washing tower and a three-stage medicine adding mechanism, wherein a gas outlet of the two-stage washing tower is communicated with a gas inlet of the three-stage washing tower through the three-stage connecting pipe, the three-stage oxygen supplementing mechanism is arranged on the three-stage connecting pipe, and the three-stage medicine adding mechanism is communicated with a liquid inlet of the three-stage washing tower;
and the discharge device is communicated with a gas outlet of the third-stage washing tower.
2. The waste gas treatment system for the circuit board nitric acid stripping and hanging rack of claim 1, wherein the first-stage washing tower, the second-stage washing tower and the third-stage washing tower comprise a circulating pump, and a collecting tank, a packing layer, a spraying layer and a defogging layer which are sequentially arranged from bottom to top; the spraying layer of the primary washing tower is connected with the primary dosing mechanism; the spraying layer of the secondary washing tower is connected with the secondary dosing mechanism; the spraying layer of the three-stage washing tower is connected with the three-stage dosing mechanism; the collecting tanks of the first-stage washing tower, the second-stage washing tower and the third-stage washing tower are respectively communicated with the spraying layer through circulating pumps.
3. The waste gas treatment system for the nitric acid stripping and hanging rack of the circuit board according to claim 1, wherein the primary oxygen supplementing mechanism, the secondary oxygen supplementing mechanism and the tertiary oxygen supplementing mechanism are all a set of adjustable air valves.
4. The waste gas treatment system for the circuit board nitric acid stripping and hanging rack of claim 1, wherein the primary dosing mechanism comprises a first alkali liquor dosing barrel, a first alkali liquor dosing pump, an oxidation liquid dosing barrel, an oxidation liquid dosing pump, a first pH controller and a first ORP controller, the first alkali liquor dosing barrel is communicated with a liquid inlet of the primary washing tower through the first alkali liquor dosing pump, and the oxidation liquid dosing barrel is communicated with a liquid inlet of the primary washing tower through the oxidation liquid dosing pump;
the first alkali liquor dosing pump is electrically connected with the first pH controller, the oxidizing liquid dosing pump is electrically connected with the first ORP controller, alkali liquor is arranged in the first alkali liquor dosing barrel and comprises Na2CO3At least one of NaOH; NaClO and NaClO are arranged in the oxidizing liquid dosing barrel2、NaClO3At least one of (1).
5. The waste gas treatment system for the circuit board nitric acid stripping hanging rack of claim 1, wherein the secondary dosing mechanism comprises a second alkaline solution dosing barrel, a second alkaline solution dosing pump, a reducing solution dosing barrel, a reducing solution dosing pump, a second pH controller and a second ORP controller, the second alkaline solution dosing barrel is communicated with a liquid inlet of the secondary washing tower through the second alkaline solution dosing pump, and the reducing solution dosing barrel is communicated with a liquid inlet of the secondary washing tower through the reducing solution dosing pump;
the second alkaline solution dosing pump is electrically connected with the second pH controller, the reducing solution dosing pump is electrically connected with the second ORP controller, an alkaline solution is arranged in the second alkaline solution dosing barrel, and the alkaline solution comprises Na2CO3At least one of NaOH; na is arranged in the reducing liquid medicine adding barrel2S2O3。
6. The waste gas treatment system for the circuit board nitric acid stripping and hanging rack of claim 1, wherein the third-level dosing mechanism comprises a third alkali liquor dosing barrel, a third alkali liquor dosing pump, a neutralization washing liquid dosing barrel, a neutralization washing liquid dosing pump, a third pH controller and a third ORP controller, the third alkali liquor dosing barrel is communicated with the liquid inlet of the third-level washing tower through the third alkali liquor dosing pump, and the neutralization washing liquid dosing barrel is communicated with the liquid inlet of the third-level washing tower through the neutralization washing liquid dosing pump;
the third alkali liquor dosing pump and the standThe third pH controller is electrically connected, the neutralization washing liquid dosing pump is electrically connected with the third ORP controller, an alkali liquid is arranged in the third alkali liquid dosing barrel, and the alkali liquid comprises Na2CO3At least one of NaOH; na is arranged in the neutralization washing liquid medicine adding barrel2S2O3。
7. The waste gas treatment system for the circuit board nitric acid stripping rack of claim 1, wherein the discharge device comprises an exhaust pipe, an exhaust valve and an exhaust fan, the gas outlet of the three-stage washing tower is connected with the exhaust fan through the exhaust pipe, and the exhaust valve is arranged on the exhaust pipe.
8. A method for treating waste gas from nitric acid stripping racks of circuit boards using the system of any of claims 1-7, comprising the steps of:
s1, adding a nitric acid volatilization inhibitor into the nitric acid stripping groove through a nitric acid volatilization inhibitor adding device, wherein the concentration of nitric acid in the nitric acid stripping groove is 40-45%; the concentration of the nitric acid volatilization inhibitor is 90-99%, and the addition amount is 25-100L/day; the nitric acid volatilization inhibitor comprises 5 to 15 weight percent of sulfonic acid, 5 to 15 weight percent of ferric nitrate, 0.1 to 0.5 weight percent of formaldehyde solution, 0.3 to 0.7 weight percent of benzotriazole and 0.1 to 1 weight percent of PEG; wherein the sulfonic acid is one or two of sulfamic acid and alkyl sulfonic acid; the PEG is one or more of PEG 200-PEG 6000;
s2, opening a primary oxygen supplementing mechanism to add air volume into the primary washing tower; opening a first-stage dosing mechanism to add liquid medicine into the first-stage washing tower for washing;
s3, opening a secondary oxygen supplementing mechanism to add air volume into the secondary washing tower; opening a secondary dosing mechanism to add liquid medicine into a secondary washing tower for washing;
s4, opening a three-stage oxygen supplementing mechanism to add air volume into the three-stage washing tower; opening a three-stage dosing mechanism to add liquid medicine into the three-stage washing tower for washing;
and S5, opening the discharging device, and discharging the waste gas which reaches the standard after being treated by the three-stage washing tower at high altitude through the discharging device.
9. The method of claim 8, wherein in step S2, the alkaline oxidizer solution comprises a separate alkali solution and an oxidizing solution, and the alkali solution comprises Na2CO3At least one of NaOH; the oxidizing solution comprises NaClO and NaClO2、NaClO3At least one of; the pH value control range of the alkali liquor is 9-11; the ORP value control range of the oxidation liquid is 20-200 mv; the reaction time of the waste gas with the alkali liquor and the oxidizing liquid is 1.5-5 seconds;
in the step S3, the alkaline reducing agent solution includes an alkaline solution and a reducing solution separately stored, and the alkaline solution includes Na2CO3At least one of NaOH; the reducing solution comprises Na2S2O3Solution of said Na2S2O3The concentration of the solution is controlled to be 2-10 percent; the reaction time of the waste gas, the alkali liquor and the reducing liquid is 4-15 seconds; the pH value control range of the alkali liquor is 9-11; the ORP value control range of the reducing liquid is-160 to-100 mv;
in the step S4, the alkaline reducing agent solution includes an alkaline solution and a neutralizing washing solution, the alkaline solution includes Na2CO3At least one of NaOH; the neutralization washing solution comprises Na2S2O3Solution of said Na2S2O3The concentration of the solution is controlled to be 2-10 percent; the reaction time of the waste gas with the alkali liquor and the neutralization washing liquid is 4-15 seconds; the pH value control range of the alkali liquor is 9-12; the ORP value of the stock solution of the neutralization washing liquid is controlled within the range of-160 to-100 mv.
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Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
"印制电路板产污环节分析和清洁生产";张仲仪;《印制电路信息》;20081231;57 *

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