CN114053834A - External circulation cleaning treatment method and system for cyanogen-containing SRG gas - Google Patents

External circulation cleaning treatment method and system for cyanogen-containing SRG gas Download PDF

Info

Publication number
CN114053834A
CN114053834A CN202010779000.1A CN202010779000A CN114053834A CN 114053834 A CN114053834 A CN 114053834A CN 202010779000 A CN202010779000 A CN 202010779000A CN 114053834 A CN114053834 A CN 114053834A
Authority
CN
China
Prior art keywords
washing tower
wastewater
gas
sulfuric acid
tower
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202010779000.1A
Other languages
Chinese (zh)
Other versions
CN114053834B (en
Inventor
李佳
朱刚
杨本涛
彭建宏
罗同维
肖海娟
肖祁春
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hunan Zhongye Changtian Energy Conservation And Environmental Protection Technology Co ltd
Zhongye Changtian International Engineering Co Ltd
Original Assignee
Hunan Zhongye Changtian Energy Conservation And Environmental Protection Technology Co ltd
Zhongye Changtian International Engineering Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hunan Zhongye Changtian Energy Conservation And Environmental Protection Technology Co ltd, Zhongye Changtian International Engineering Co Ltd filed Critical Hunan Zhongye Changtian Energy Conservation And Environmental Protection Technology Co ltd
Priority to CN202010779000.1A priority Critical patent/CN114053834B/en
Publication of CN114053834A publication Critical patent/CN114053834A/en
Application granted granted Critical
Publication of CN114053834B publication Critical patent/CN114053834B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • 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
    • B01D53/14—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 by absorption
    • B01D53/1406—Multiple stage absorption
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D47/00—Separating dispersed particles from gases, air or vapours by liquid as separating agent
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D47/00—Separating dispersed particles from gases, air or vapours by liquid as separating agent
    • B01D47/06—Spray cleaning
    • 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
    • B01D53/14—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 by absorption
    • B01D53/1456—Removing acid components
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B17/00—Sulfur; Compounds thereof
    • C01B17/69—Sulfur trioxide; Sulfuric acid
    • C01B17/74—Preparation
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/20—Treatment of water, waste water, or sewage by degassing, i.e. liberation of dissolved gases
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F9/00—Multistage treatment of water, waste water or sewage
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/20—Halogens or halogen compounds
    • B01D2257/202—Single element halogens
    • B01D2257/2025—Chlorine
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/20—Halogens or halogen compounds
    • B01D2257/202—Single element halogens
    • B01D2257/2027—Fluorine
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/40—Nitrogen compounds
    • B01D2257/408—Cyanides, e.g. hydrogen cyanide (HCH)
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F2001/007—Processes including a sedimentation step
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
    • C02F2103/18—Nature of the water, waste water, sewage or sludge to be treated from the purification of gaseous effluents

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Chemistry (AREA)
  • Water Supply & Treatment (AREA)
  • Environmental & Geological Engineering (AREA)
  • Hydrology & Water Resources (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Analytical Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Inorganic Chemistry (AREA)
  • Treating Waste Gases (AREA)
  • Gas Separation By Absorption (AREA)

Abstract

An external circulation cleaning treatment method of cyanogen-containing SRG gas comprises the following steps: 1) the cyanogen-containing SRG gas sequentially passes through a first-stage washing tower, a second-stage washing tower and a third-stage washing tower, and the washed gas is discharged from the top of the third-stage washing tower; 2) discharged from a three-stage washing towerThe gas enters an acid making system to make acid to obtain concentrated sulfuric acid; 3) the process water is washed and purified by a third-stage washing tower, a second-stage washing tower and a first-stage washing tower in sequence, the waste water in the first-stage washing tower after washing and purification is discharged to a primary settling tank, and the waste water at the upper part of the primary settling tank enters SO2A desorption tower; SO (SO)2SO in desorption tower desorption wastewater2Then discharging the wastewater to a wastewater collection tank; 4) conveying process water and concentrated sulfuric acid into a concentrated sulfuric acid diluter for mixing to obtain dilute sulfuric acid; and (3) introducing dilute sulfuric acid into a wastewater collection tank, reacting the dilute sulfuric acid with wastewater, and discharging acidic washing wastewater. The invention prevents secondary pollution and improves the yield of acid production by acidification stripping and waste gas circulation to the inside of the system.

Description

External circulation cleaning treatment method and system for cyanogen-containing SRG gas
Technical Field
The invention relates to a method for treating SRG gas, in particular to an external circulation cleaning treatment method and system for cyanogen-containing SRG gas, and belongs to the field of resource environment protection.
Background
Sintering flue gas in the steel industry is subjected to a flue gas purification process by adopting an activated carbon method for desulfurization and denitrification, and sulfur dioxide gas collected by activated carbon is concentrated and released and then is sent to a sulfur resource workshop to produce sulfur resources. The flue gas enriched with sulfur dioxide gas is called sulfur-enriched gas (SRG flue gas) for short, and the gas can be processed by the procedures of purification, drying, conversion, absorption and the like to prepare sulfur resources meeting the national standard, and the resource recovery value is high. But the purification process in the process of producing sulfur resources can simultaneously wash impurities and harmful elements in the flue gas and enter the acidic washing wastewater, and meanwhile, part of sulfur dioxide gas in the flue gas can also be absorbed by water vapor and brought into the wastewater.
In general, acidic scrubbing wastewater tends to be acidic because the amount of acidic species in the SRG gas is greater than the amount of basic species. When cyanide and derivatives thereof exist in the front-end flue gas, the cyanide and the derivatives thereof enter the SRG gas and are finally dissolved in the acidic washing wastewater, so that the alkalinity of the wastewater is increased (for example, cyanic acid is hydrolyzed to generate ammonia nitrogen), and the acidic washing wastewater is neutral. The acidic washing wastewater is neutral, SO a large amount of SO in SRG gas can be caused2The acid gas dissolves, causing a sharp increase in the hydrogen sulfite in the wastewater. The detection result shows that the concentration of the bisulfite in the acidic washing wastewater generated by the washing of the cyanide-free SRG gas is 2-5 g/L, and the concentration of the bisulfite in the acidic washing wastewater generated by the washing of the cyanide-containing SRG gas is 240-300 g/L.
If the acidic washing wastewater with high concentration of bisulfite enters a subsequent wastewater treatment system, the treatment difficulty is huge. On one hand, the alkali consumption is increased sharply, the waste of liquid alkali is caused, and the discharge amount of waste water is increased; in addition, sodium sulfite crystals are formed and precipitated in the process of adding alkali, and system blockage and paralysis are caused.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide an external circulation cleaning treatment method and system for cyanogen-containing SRG gas. The invention dilutes part of concentrated sulfuric acid prepared in the acid making process, adjusts the washing wastewater into acidity, and then discharges the washing wastewater, and utilizes the system to treat the waste gas, thereby preventing secondary pollution, and realizing that the salt content of the acidic washing wastewater is greatly reduced and the yield of sulfuric acid is greatly improved.
According to a first embodiment of the present invention, there is provided a method for the external recycle cleaning remediation of cyanogen-containing SRG gas.
An external circulation cleaning treatment method of cyanogen-containing SRG gas comprises the following steps:
1) and (2) introducing the SRG gas containing cyanogen into the first-stage washing tower from the lower part, sequentially passing the SRG gas through the first-stage washing tower, the second-stage washing tower and the third-stage washing tower, respectively carrying out countercurrent contact on the SRG gas and the washing solution in each tower, and discharging the washed gas from the top of the third-stage washing tower.
2) And (4) gas discharged from the top of the third-stage washing tower enters an acid making system to make acid, so that concentrated sulfuric acid is obtained.
3) The process water enters a third-stage washing tower from the bottom, the process water sequentially passes through the third-stage washing tower, a second-stage washing tower and a first-stage washing tower to wash and purify the SRG gas containing cyanogen, the wastewater in the first-stage washing tower after washing and purification is discharged to a primary settling tank, and the wastewater at the upper part of the primary settling tank enters SO2A desorption tower. SO (SO)2Desorption tower for removing physically dissolved SO from wastewater2And then discharging the wastewater to a wastewater collection tank.
4) Conveying the process water and the concentrated sulfuric acid prepared in the step 2) into a concentrated sulfuric acid diluter for mixing to obtain dilute sulfuric acid. And (3) introducing dilute sulfuric acid into a wastewater collection tank, reacting the dilute sulfuric acid with wastewater, and discharging acidic washing wastewater after reaction.
In the present invention, the method comprises: 5) using the concentrated sulfuric acid prepared in the step 2) for sale.
Preferably, in the step 4), compressed air is introduced into the waste water collecting tank when the dilute sulfuric acid reacts with the waste water.
Preferably, in the step 3), the wastewater at the lower part of the primary settling tank is introduced into a wastewater collection tank. Preferably, the wastewater at the lower part of the primary settling tank is also introduced into a sludge storage tank.
In the invention, one part of the wastewater at the lower part (or the bottom) of the primary settling tank is introduced into a wastewater collecting tank, and the other part of the wastewater is introduced into a sludge storage tank for further treatment. The amount of the wastewater introduced into the wastewater collection tank is 1/20-1/30 of the total amount of the wastewater in the primary sedimentation tank.
Preferably, in step 1), the SRG gas is firstly mixed with SO after passing through the first-stage washing tower2The sulfur-containing gas generated by the desorption tower is converged and then enters a secondary washing tower for washing and purification. Preferably, in the step 4), the waste gas after the reaction of the dilute sulfuric acid and the waste water is introduced into SO2A desorption tower.
Preferably, in step 3), SO is removed from the wastewater2In time, toSO2And introducing air into the desorption tower.
In step 3) of the present invention, a part of the wastewater in the upper part of the primary settling tank enters (overflows to) SO2The other part of the desorption tower is introduced into (overflows to) the first-stage washing tower.
In the invention, the wastewater at the upper part of the primary settling tank enters SO2The volume ratio of the waste water amount of the desorption tower to the waste water amount introduced into the first-stage washing tower is 1: 5-10.
Preferably, in the step 3), a part of the process water entering the third-stage washing tower is recycled in the third-stage washing tower, and the other part of the process water enters the second-stage washing tower. And a part of the process water entering the second-stage washing tower from the third-stage washing tower is recycled in the second-stage washing tower, and the other part of the process water enters the first-stage washing tower.
In the invention, the primary washing tower, the secondary washing tower and the tertiary washing tower aim to remove impurities in the SRG gas by wet washing, and the gas and the solution in the washing towers are in reverse contact, namely the gas flows from bottom to top, and the solution flows from top to bottom. Wherein the volume ratio of the solution amount recycled in the third washing tower to the solution amount introduced into the second washing tower is 5-12: 1. The volume ratio of the solution amount recycled in the secondary washing tower to the solution amount introduced into the primary washing tower is 5-12: 1.
In the step 4), the pH value of the acidic washing wastewater after the reaction of the dilute sulfuric acid and the wastewater is 0-3, preferably 0.5-2.5, and more preferably 1-2.
Preferably, in the step 4), the amount of the dilute sulfuric acid introduced into the wastewater collection tank is such that the ratio of the molar amount of the hydrogen ions in the dilute sulfuric acid to the molar amount of the sulfite ions in the wastewater is 1:0.1-1, preferably 1:0.2-0.6, and more preferably 1: 0.3-0.5.
That is, in the present invention, only a part of the concentrated sulfuric acid produced in step 2) is fed (as needed) to the primary washing tower, and the remaining part of the concentrated sulfuric acid is still available for sale.
Preferably, the concentration of the sulfuric acid in the dilute sulfuric acid is 30-80%, preferably 40-70%, and more preferably 50-60%.
In the step 3), the pH value of the liquid entering the three-stage washing tower is 5-7, preferably 5.5-6.5.
Preferably, in the step 3), the pH value of the liquid entering the secondary washing tower is 3-5, and preferably 3.5-4.5.
Preferably, in the step 3), the pH value of the liquid entering the first-stage washing tower is 2-4, and preferably 2.5-3.5.
Preferably, in the step 3), the pH value of the liquid discharged from the primary washing tower is 4-6, preferably 4.5-5.5.
In step 1) of the present invention, the temperature of the SRG gas entering the primary scrubber is 250 to 480 ℃, preferably 300 to 450 ℃, and more preferably 380 to 430 ℃.
Preferably, in the step 1), the temperature of the gas entering the secondary washing tower is 50-150 ℃, and preferably 70-100 ℃.
Preferably, in the step 1), the temperature of the gas entering the third-stage washing tower is 10-80 ℃, and preferably 30-60 ℃.
Preferably, in the step 1), the temperature of the gas discharged from the third-stage washing tower is 10 to 60 ℃, and preferably 20 to 40 ℃.
In the step 3), the temperature of the liquid entering the third-stage washing tower is 10-60 ℃, and preferably 20-40 ℃.
Preferably, in the step 3), the temperature of the liquid entering the secondary washing tower is 10-80 ℃, and preferably 30-60 ℃.
Preferably, in the step 3), the temperature of the liquid entering the first-stage washing tower is 30-100 ℃, and preferably 50-80 ℃.
Preferably, in the step 3), the temperature of the liquid discharged from the primary washing tower is 50 to 120 ℃, and preferably 70 to 90 ℃.
In the invention, the concentration of suspended matters in the wastewater collection tank is 600-2500 mg/L, preferably 800-2300 mg/L.
In the invention, a part of the wastewater at the bottom of the primary settling tank is introduced into the wastewater collection tank, so that the content of suspended matters in the wastewater collection tank is controlled, and the adsorption of colloidal sulfur is realized.
In the step 3), the concentration of suspended matters in the wastewater at the upper part of the primary settling tank is 0-100 mg/L, preferably 1-80 mg/L, and more preferably 2-50 mg/L.
The primary settling tank removes suspended matters through the settling action of the self gravity of the suspended matters.
According to a second embodiment of the present invention, an external circulation cleaning abatement system for cyanogen-containing SRG gas is provided.
A system for clean remediation of cyanogen-containing SRG gas using the above method, the system comprising: a first-stage washing tower, a second-stage washing tower, a third-stage washing tower, an acid making system, a primary settling tank and SO2Desorption tower, waste water collecting tank, concentrated sulfuric acid diluter. The SRG gas conveying pipeline is connected to a gas inlet of the first-stage washing tower, a gas outlet of the first-stage washing tower is connected to a gas inlet of the second-stage washing tower through a first pipeline, a gas outlet of the second-stage washing tower is connected to a gas inlet of the third-stage washing tower through a second pipeline, and a gas outlet of the third-stage washing tower is connected to an acid making system through a third pipeline.
The first process water conveying pipeline is connected to a bottom liquid inlet of the third-stage washing tower, a liquid outlet of the third-stage washing tower is connected to a lower liquid inlet of the second-stage washing tower through a fourth pipeline, a liquid outlet of the second-stage washing tower is connected to a lower liquid inlet of the first-stage washing tower through a fifth pipeline, a liquid outlet of the first-stage washing tower is connected to the primary settling tank through a sixth pipeline, an upper liquid outlet of the primary settling tank is connected to the SO through a seventh pipeline2A liquid inlet of the desorption column. SO (SO)2The liquid outlet of the desorption tower is connected to a waste water collecting tank through an eighth pipeline. A liquid outlet of the acid making system is connected to the concentrated sulfuric acid diluter through a concentrated sulfuric acid conveying pipeline, and a second process water conveying pipeline is connected to the concentrated sulfuric acid diluter. And a liquid outlet of the concentrated sulfuric acid diluter is connected to a liquid inlet of the wastewater collecting tank through a ninth pipeline.
Preferably, the compressed air delivery conduit is connected to the gas inlet of the waste water collection tank.
Preferably, the bottom liquid outlet of the primary settling tank is connected to the liquid inlet of the wastewater collection tank via a tenth pipe. Preferably, an eleventh pipeline branches from the tenth pipeline, and the eleventh pipeline is connected to the sludge storage tank.
Preferably, a twelfth conduit leading from the waste gas outlet of the waste water collecting tank is connected to the SO2A gas inlet of the desorption tower. SO (SO)2The gas outlet of the desorption column is connected to the first conduit via a thirteenth conduit.
Preferably, the air delivery duct is connected to the twelfth duct.
Preferably, a fourteenth pipe branches off from the seventh pipe, and the fourteenth pipe is connected to the upper liquid inlet of the primary scrubber.
Preferably, a fifteenth pipe branches off from the fifth pipe, and the fifteenth pipe is connected to the upper liquid inlet of the secondary scrubber. And a sixteenth pipeline is branched from the fourth pipeline, and the sixteenth pipeline is connected to the upper liquid inlet of the third-stage washing tower.
In the invention, the gas inlet of the first-stage washing tower, the second-stage washing tower or the third-stage washing tower is arranged at the lower part of the corresponding device, and the gas outlet is arranged at the top of the corresponding device. The bottom liquid inlet is typically located at the bottom of the device. While the upper liquid inlet and the lower liquid inlet are a relative concept, generally, the upper liquid inlet is disposed at an upper portion of the apparatus, the lower liquid inlet is disposed at a lower portion of the apparatus, and the upper liquid inlet is located above the lower liquid inlet. The upper liquid outlet and the lower liquid outlet are also a relative concept, and in general, the upper liquid outlet is located above the lower liquid outlet.
In the prior art, after SRG gas is washed and purified by process water, sulfur dioxide gas with higher purity is obtained and used for two-conversion and two-absorption acid making, and waste water generated after washing is finally discharged from a system after passing through a stripping tower to form acid washing waste water. Generally, the acid species in the SRG gas are greater than the amount of basic species, and therefore, the acidic wash wastewater tends to be acidic. However, when cyanide and its derivatives exist in the front-end flue gas, the cyanide and its derivatives enter the SRG gas and finally dissolve in the washing wastewater, and the dissolution of cyanide and its derivatives increases the alkalinity of the washing wastewater due to the hydrolysis of cyanic acid to generate ammonia nitrogen, so that the washing wastewater is neutral. When the washing wastewater is neutral, a large amount of SO in the SRG gas is generated2The acid gas dissolves, causing a sharp increase in sulfite in the wastewater. The treatment difficulty of the washing wastewater of the high-concentration sulfite is huge.
Considering the condition that cyanide and derivatives thereof exist in front-end flue gas, the self-generated sulfuric acid is diluted and then is discharged after the washing wastewater is adjusted to be acidic, and the self-generated sulfuric acid is utilized to treat the waste gas. Through this improvement, there are the following advantages:
the cyanide and the derivative thereof are finally hydrolyzed into ammonium ions, so that the washing liquid is weakly acidic or neutral. According to SO3 2-The ion fraction curve of (2) shows that SO is present in a weakly acidic or neutral solution2Will dissolve to become bisulfite. Thus, the solution used to scrub SRG is primarily ammonium bisulfite (NH)4HSO3) In the presence of a cyanide compound and its derivatives, which are obtainable by the reactions (1) and (2), a sulfur dioxide can be reacted with one cyanide compound. Because the formation of bisulfate requires lower pH, dilute sulfuric acid is added into the wastewater, and ammonium bisulfite can be decomposed into SO by reasonable control2The solution is mainly present as ammonium sulfate. According to reaction (3), two cyanides and derivatives thereof are required to react with one sulfate.
Hydrolysis of cyanide and its derivatives: HOCN + H2O→NH3+CO2 (1)
The solution reacts under weak acidity or neutrality: NH (NH)3+SO2+H2O→NH4HSO3 (2)
After the solution is adjusted to be acid: 2NH4HSO3+H2SO4→(NH4)2SO4+2H2O+2SO2 (3)
According to the reaction process, the salt content of the acidic washing wastewater can be greatly reduced, and the yield of sulfuric acid can be greatly improved. Before the process of the invention is adopted, the amount of wastewater is 4m according to the detection result3The chloride ion content is 40g/L, the total concentration of sulfate radical and bisulfite radical is 238g/L, and the concentration of bisulfite radical is 160g/L。
Figure BDA0002619532750000051
The mass concentration of the salt is reduced, namely the mass concentration of ammonium bisulfite-the mass concentration of ammonium sulfate,
Figure BDA0002619532750000052
thus, the percentage reduction in the salt mass concentration is the ratio of the salt mass concentration reduced after the process of the invention to the salt mass concentration before the process of the invention:
the salt concentration reduction percentage is reduced salt mass concentration ÷ (original ammonium sulfate mass concentration + ammonium bisulfite mass concentration + ammonium chloride mass concentration);
obtaining the following components:
Figure BDA0002619532750000053
the reaction does not occur completely due to the presence of incomplete reaction. Therefore, according to the actual improvement result, the salt content in the acidic wastewater can be reduced by about 14.4% after the process of the invention is adopted.
Further, from the reaction (3), it is understood that 1mol of sulfur dioxide is generated in the post-reforming process corresponding to 1mol of the reaction system, while 0.5mol of sulfuric acid is consumed, that is, 0.5mol of sulfuric acid is generated. According to the detection result, the acid yield before process modification is 32 t/d. The reaction process for preparing sulfuric acid by using sulfur dioxide comprises the following steps:
and a sulfur dioxide conversion process: 2SO2+O2→2SO3 (4)
An absorption process: SO (SO)3+H2O→H2SO4 (5)
Thus, the increase in 98% sulfuric acid yield is the amount of sulfuric acid added per cubic water x the amount of water x 24h ÷ sulfuric acid mass fraction;
namely: increase the sulfuric acid yield of 98% ═ 160/81 × 98 × 4 × 24/1000/98% ═ 18.96 t/d;
the reaction consumed 98% of sulfuric acid 160/81 × 98 × 4 × 24/1000/98%/2 ═ 9.48 t/d;
the total increase in sulfuric acid (increase in 98% sulfuric acid production-98% sulfuric acid consumed by the reaction) x actual reaction efficiency, i.e.:
the total increased sulfuric acid amount is 9.48 × 14.4/17.95 ═ 7.61 t/d;
the acid yield reaches 39.61t/d after modification.
Thus, the sulfuric acid yield increased by 23.78% using the process of the present invention.
Secondly, after the acid washing wastewater in the wastewater collection tank reacts with dilute sulfuric acid, ammonium bisulfite can be decomposed into SO2After compressed air is introduced, the reaction is intensified and a large amount of acid gas is discharged. If the acid gas is discharged randomly, the air pollution can be caused. Due to SO2The desorption tower adopts negative pressure gas inlet to introduce the acidic gas generated by the reaction into SO2The desorption tower further enters a secondary washing tower, so that atmospheric pollution can be avoided and sulfur resource recovery can be realized.
The sulfuric acid produced by the two-rotation and two-absorption process is directly added into the system, so that the internal recycling of sulfur resources is realized, additional substances are avoided, the operation is simple, and the improvement is convenient.
In addition, in the prior art, the SRG gas is washed by the washing solution in the first-stage washing tower, the waste water at the lower part of the first-stage washing tower after washing and purification is introduced into the conical settling tank, and the waste water at the upper part of the conical settling tank overflows to the supernatant storage tank. According to actual research, carbon powder in the washing wastewater is fine, and when a conical settling tank and a supernatant storage tank are adopted, the carbon powder is not sufficiently settled due to large disturbance in water in the operation process, so that the solution circulated to the first-stage washing tower also contains more carbon powder. After circulating for several times, the carbon powder amount in the solution will increase rapidly, and in order to avoid the blockage of the washing nozzle, the discharge of acid-making waste water needs to be increased. In the invention, the primary settling tank is adopted to replace a conical settling tank and a supernatant storage tank. Because the primary settling tank adopts a mode of feeding the middle part and discharging the carbon powder from two sides, the hydraulic disturbance is less, and the carbon powder is favorably settled, so the discharge amount of the acid-making wastewater is less.
Before the process of the invention is adopted, because the suspended substances in the wastewater are higher and have to be discharged, the concentration of the chloride ions in the water is generally 50000 mg/L. After improvement, the suspended matter is low and is no longer used as a control index. The control index can be adjusted to detect the chloride ion concentration in the primary settling tank to be 70000 mg/L. The waste water can be concentrated by 1.4 times, and the water quantity can be reduced by 28.6 percent. According to practical improvement results, the amount of water entering the wastewater collection tank can be reduced by about 25%.
The invention provides an external circulation cleaning treatment method and system for cyanogen-containing SRG gas, wherein the technical process and the technical principle are briefly described as follows:
carrying out three-stage washing: according to the SRG gas composition properties, three-stage washing is adopted, wherein the first stage is used for removing dust, cyanide and derivatives thereof and a small amount of fluorine and chlorine in the SRG gas, and simultaneously reducing the temperature of the flue gas. The second stage is mainly used for removing fluorine and chlorine, deeply removing impurities and further reducing the temperature of the SRG gas. The third stage is a pollutant deep removal section for removing pollutants which cannot be removed due to fluctuation of the first two stages.
② separating carbon powder: the carbon powder is removed by utilizing the principle that the carbon powder is easy to settle by the self gravity. According to the invention, the primary settling tank is adopted to replace a conical settling tank and a supernatant storage tank, and the primary settling tank adopts a mode of feeding water into the middle and discharging the water from the middle and from the two sides, so that the water inlet and the water outlet and the sludge discharge are independent, disturbance basically does not exist, and secondary suspension of settled fine carbon powder can be avoided.
Thirdly, acidification stripping: the pH value of the wastewater solution generated by washing in the first-stage washing tower is 4-6, and the wastewater solution contains a large amount of ammonium bisulfite. After addition of dilute sulfuric acid to the solution, bisulfite in the ammonium bisulfite is converted to sulfurous acid. Sulfurous acid decomposes to release sulfur dioxide under acid and air turbulence. One sulfate is used to replace two bisulfite groups, thereby reducing the salt concentration. The research shows that the acidification stripping is an endothermic reaction, and the risk of bumping does not exist. However, the concentration of the added dilute sulfuric acid is not too high, which can cause equipment corrosion, and the reaction is violent, which generates local high temperature. But the concentration of the added dilute sulfuric acid is not too low, and if the concentration of the added dilute sulfuric acid is too low, the reaction speed is slow, the average acid consumption is increased, and a large amount of wastewater is generated. Therefore, the concentration of the dilute sulfuric acid is preferably selected to be medium-high (for example, the concentration of the sulfuric acid in the dilute sulfuric acid is 30 to 80%, preferably 40 to 70%, and more preferably 50 to 60%).
④SO2Stripping and recovering: the acidic washing wastewater contains a certain amount of sulfurous acid in SO2Air is introduced into the desorption tower, so that the decomposition of the sulfurous acid can be accelerated, and the sulfur dioxide is blown out. In addition, sulfur dioxide removed by acidification and blowing enters SO2The negative pressure pipeline of the desorption tower prevents sulfur dioxide from escaping, and simultaneously can recover sulfur resources and improve the yield of sulfuric acid.
Adsorbing colloidal sulfur: studies have shown that SRG gas, which contains sulfur vapor, is washed into solution in the first-stage column and further reacts with bisulfite to form thiosulfate. The thiosulfate radicals enter a wastewater collection tank along with wastewater and are decomposed under an acidic condition to generate colloidal sulfur. Based on the property of adsorbing colloidal sulfur by activated carbon, the invention transfers the wastewater (namely the carbon powder part) at the bottom of the primary precipitation tank into a wastewater collection tank, realizes the deep removal of the colloidal sulfur and prevents the colloidal sulfur from sticking equipment to cause blockage.
The external circulation cleaning treatment method and the external circulation cleaning treatment system for the cyanogen-containing SRG gas can be used for treating desorption gas of an adsorbent by an adsorption method, and the cyanogen-containing SRG gas is only one of the cyanogen-containing SRG gas. Wherein the adsorbent comprises solid or liquid, for example, the adsorbent is one or more of activated carbon, molecular sieves, MOFs, ionic liquids, and organic amines.
Compared with the prior art, the invention has the following beneficial technical effects:
1. the invention can realize the clean treatment of the SRG gas by reasonably designing the SRG gas washing process and utilizing the SRG product and reasonably designing the washing and purifying process on the basis of not adding other substances.
2. The invention circulates the waste gas to the inside of the system through acidification stripping and simultaneously based on the characteristics of the system, thereby preventing secondary pollution and improving the yield of acid.
3. The salt content of the acidic washing wastewater discharged by the invention is greatly reduced, the treatment cost of the acidic washing wastewater is correspondingly reduced, and the subsequent treatment cost can be reduced.
4. The invention adopts neutral washing to convert the elemental sulfur into a dissolved state, avoids blocking washing equipment, and combines the adsorption of the waste carbon powder to control the decomposed colloidal sulfur source and avoid blocking the equipment.
Drawings
FIG. 1 is a process flow diagram of the external circulation cleaning treatment method of cyanogen-containing SRG gas of the present invention;
FIG. 2 is a schematic structural diagram of an external circulation cleaning and treating system for cyanogen-containing SRG gas according to the present invention;
FIG. 3 is SO3 2-Ion fraction graph of (a).
Reference numerals: 1: a first-stage washing tower; 2: a secondary washing tower; 3: a third stage washing tower; 4: an acid making system; 5: primary settling tank; 6: SO (SO)2A desorption tower; 7: a wastewater collection tank; 8: a concentrated sulfuric acid diluter; 9: a sludge storage tank;
la: an SRG gas delivery line; lb: a first process water delivery pipeline; lc: a concentrated sulfuric acid delivery pipeline; and Ld: a second process water delivery pipeline; le: a compressed air delivery conduit; lf: an air delivery conduit;
l1: a first conduit; l2: a second conduit; l3: a third pipeline; l4: a fourth conduit; l5: a fifth pipeline; l6: a sixth pipeline; l7: a seventh pipe; l8: an eighth conduit; l9: a ninth conduit; l10: a tenth conduit; l11: an eleventh pipe; l12: a twelfth duct; l13: a thirteenth pipe; l14: a fourteenth pipe; l15: a fifteenth conduit; l16: a sixteenth conduit.
Detailed Description
According to a first embodiment of the present invention, there is provided a method for the external recycle cleaning remediation of cyanogen-containing SRG gas.
An external circulation cleaning treatment method of cyanogen-containing SRG gas comprises the following steps:
1) the SRG gas containing cyanogen enters a first-stage washing tower 1 from the lower part, the SRG gas sequentially passes through the first-stage washing tower 1, a second-stage washing tower 2 and a third-stage washing tower 3, the SRG gas is respectively in countercurrent contact with washing solutions in the towers, and the washed gas is discharged from the top of the third-stage washing tower 3.
2) And gas discharged from the top of the third-stage washing tower 3 enters an acid making system 4 to make acid, so that concentrated sulfuric acid is obtained.
3) The process water enters a third-stage washing tower 3 from the bottom, the process water washes and purifies the cyanogen-containing SRG gas through the third-stage washing tower 3, a second-stage washing tower 2 and a first-stage washing tower 1 in sequence, the wastewater in the first-stage washing tower 1 after washing and purification is discharged to a primary settling tank 5, and the wastewater on the upper part of the primary settling tank 5 enters SO2And a desorption tower 6. SO (SO)2 Desorption tower 6 for removing SO physically dissolved in wastewater2And then discharges the wastewater to the wastewater collection tank 7.
4) Conveying the process water and the concentrated sulfuric acid prepared in the step 2) into a concentrated sulfuric acid diluter 8 for mixing to obtain dilute sulfuric acid. Dilute sulfuric acid is introduced into a wastewater collection tank 7, the dilute sulfuric acid reacts with wastewater, and acidic washing wastewater is discharged after the reaction.
In the present invention, the method comprises: 5) using the concentrated sulfuric acid prepared in the step 2) for sale.
Preferably, in step 4), compressed air is introduced into the waste water collecting tank 7 when the dilute sulfuric acid reacts with the waste water.
Preferably, in the step 3), the wastewater at the lower part of the primary settling tank 5 is introduced into a wastewater collection tank 7. Preferably, the wastewater in the lower part of the primary settling tank 5 is also introduced into a sludge storage tank 9.
Preferably, in step 1), the SRG gas is firstly mixed with SO after passing through the first-stage washing tower 12The sulfur-containing gas generated by the desorption tower 6 is converged and then enters the second-stage washing tower 2 for washing and purification. Preferably, in the step 4), the waste gas after the reaction of the dilute sulfuric acid and the waste water is introduced into SO2And a desorption tower 6.
Preferably, in step 3), SO is removed from the wastewater2To SO2Air is introduced into the desorption tower 6.
In the step 3) of the present invention, a part of the wastewater in the upper part of the primary settling tank 5 enters SO2The other part of the desorption tower 6 is introduced into the first-stage washing tower 1.
Preferably, in step 3), a part of the process water entering the third washing tower 3 is recycled in the third washing tower 3, and the other part of the process water enters the second washing tower 2. A part of the process water entering the second-stage washing tower 2 from the third-stage washing tower 3 is recycled in the second-stage washing tower 2, and the other part of the process water enters the first-stage washing tower 1.
In the step 4), the pH value of the acidic washing wastewater after the reaction of the dilute sulfuric acid and the wastewater is 0-3, preferably 0.5-2.5, and more preferably 1-2.
Preferably, in the step 4), the amount of the dilute sulfuric acid introduced into the wastewater collection tank 7 is such that the ratio of the molar amount of the hydrogen ions in the dilute sulfuric acid to the molar amount of the sulfite ions in the wastewater is 1:0.1-1, preferably 1:0.2-0.6, and more preferably 1: 0.3-0.5.
Preferably, the concentration of the sulfuric acid in the dilute sulfuric acid is 30-80%, preferably 40-70%, and more preferably 50-60%.
In the step 3), the pH value of the liquid entering the three-stage washing tower 3 is 5-7, preferably 5.5-6.5.
Preferably, in the step 3), the pH value of the liquid entering the secondary washing tower 2 is 3-5, and preferably 3.5-4.5.
Preferably, in the step 3), the pH value of the liquid entering the first-stage washing tower 1 is 2-4, and preferably 2.5-3.5.
Preferably, in the step 3), the pH value of the liquid discharged from the primary washing tower 1 is 4 to 6, preferably 4.5 to 5.5.
In step 1) of the present invention, the temperature of the SRG gas introduced into the primary washing column 1 is 250 to 480 ℃, preferably 300 to 450 ℃, and more preferably 380 to 430 ℃.
Preferably, in the step 1), the temperature of the gas entering the secondary washing tower 2 is 50-150 ℃, and preferably 70-100 ℃.
Preferably, in the step 1), the temperature of the gas entering the third-stage washing tower 3 is 10-80 ℃, and preferably 30-60 ℃.
Preferably, in the step 1), the temperature of the gas discharged from the third washing tower 3 is 10 to 60 ℃, and preferably 20 to 40 ℃.
In the step 3), the temperature of the liquid entering the third-stage washing tower 3 is 10-60 ℃, and preferably 20-40 ℃.
Preferably, in the step 3), the temperature of the liquid entering the secondary washing tower 2 is 10-80 ℃, and preferably 30-60 ℃.
Preferably, in the step 3), the temperature of the liquid entering the first-stage washing tower 1 is 30-100 ℃, and preferably 50-80 ℃.
Preferably, in the step 3), the temperature of the liquid discharged from the primary washing tower 1 is 50 to 120 ℃, and preferably 70 to 90 ℃.
In the invention, the concentration of suspended matters in the wastewater collection tank 7 is 600-2500 mg/L, preferably 800-2300 mg/L.
In the step 3) of the present invention, the concentration of suspended matters in the wastewater at the upper part of the primary settling tank 5 is 0 to 100mg/L, preferably 1 to 80mg/L, and more preferably 2 to 50 mg/L.
According to a second embodiment of the present invention, an external circulation cleaning abatement system for cyanogen-containing SRG gas is provided.
A system for clean remediation of cyanogen-containing SRG gas using the above method, the system comprising: a first-stage washing tower 1, a second-stage washing tower 2, a third-stage washing tower 3, an acid making system 4, a primary settling tank 5 and SO2Desorption tower 6, waste water collecting tank 7, concentrated sulfuric acid diluter 8. SRG gas transmission pipeline LaIs connected to the gas inlet of the primary washing tower 1, the gas outlet of the primary washing tower 1 is connected to the gas inlet of the secondary washing tower 2 via a first pipeline L1, the gas outlet of the secondary washing tower 2 is connected to the gas inlet of the tertiary washing tower 3 via a second pipeline L2, and the gas outlet of the tertiary washing tower 3 is connected to the acid making system 4 via a third pipeline L3.
First process water conveying pipeline LbIs connected to the bottom liquid inlet of the third washing tower 3, the liquid outlet of the third washing tower 3 is connected to the lower liquid inlet of the second washing tower 2 via a fourth pipeline L4, the liquid outlet of the second washing tower 2 is connected to the lower liquid inlet of the first washing tower 1 via a fifth pipeline L5, the liquid outlet of the first washing tower 1 is connected to the primary settling tank 5 via a sixth pipeline L6, the upper liquid outlet of the primary settling tank 5 is connected to SO via a seventh pipeline L72Desorption tower6. SO (SO)2The liquid outlet of the desorption tower 6 is connected to the wastewater collection tank 7 via an eighth conduit L8. The liquid outlet of the acid making system 4 is connected to the concentrated sulfuric acid diluter 8 via a concentrated sulfuric acid conveying pipeline Lc, and a second process water conveying pipeline LdIs connected to a concentrated sulfuric acid diluter 8. The liquid outlet of the concentrated sulfuric acid diluter 8 is connected to the liquid inlet of the wastewater collection tank 7 via a ninth conduit L9.
Preferably, the compressed air delivery line Le is connected to the gas inlet of the waste water collection tank 7.
Preferably, the bottom liquid outlet of the primary settling tank 5 is connected to the liquid inlet of the wastewater collection tank 7 via a tenth pipe L10. Preferably, an eleventh pipe L11 branches off from the tenth pipe L10, and the eleventh pipe L11 is connected to the sludge storage tank 9.
Preferably, a twelfth conduit L12 leading from the waste gas outlet of the waste water collecting tank 7 is connected to the SO2A gas inlet of the desorption column 6. SO (SO)2The gas outlet of the desorption tower 6 is connected to the first conduit L1 via a thirteenth conduit L13.
Preferably, the air delivery duct Lf is connected to a twelfth duct L12.
Preferably, a fourteenth line L14 branches off from the seventh line L7, and the fourteenth line L14 is connected to the upper liquid inlet of the primary washing column 1.
Preferably, a fifteenth conduit L15 branches off from the fifth conduit L5, and the fifteenth conduit L15 is connected to the upper liquid inlet of the secondary scrubber 2. A sixteenth line L16 branches off from the fourth line L4, and a sixteenth line L16 is connected to the upper liquid inlet of the third washing column 3.
Example 1
As shown in fig. 2, an external circulation cleaning and treating system for cyanogen-containing SRG gas comprises: a first-stage washing tower 1, a second-stage washing tower 2, a third-stage washing tower 3, an acid making system 4, a primary settling tank 5 and SO2Desorption tower 6, waste water collecting tank 7, concentrated sulfuric acid diluter 8. SRG gas transmission pipeline LaIs connected to the gas inlet of the primary scrubber 1, the gas outlet of the primary scrubber 1 is connected to the gas inlet of the secondary scrubber 2 via a first pipe L1, and the gas outlet of the secondary scrubber 2 is connected to the gas inlet of the secondary scrubber 2 via a second pipeL2 is connected to the gas inlet of the tertiary scrubber 3, and the gas outlet of the tertiary scrubber 3 is connected to the acid making system 4 via a third conduit L3.
First process water conveying pipeline LbIs connected to the bottom liquid inlet of the third washing tower 3, the liquid outlet of the third washing tower 3 is connected to the lower liquid inlet of the second washing tower 2 via a fourth pipeline L4, the liquid outlet of the second washing tower 2 is connected to the lower liquid inlet of the first washing tower 1 via a fifth pipeline L5, the liquid outlet of the first washing tower 1 is connected to the primary settling tank 5 via a sixth pipeline L6, the upper liquid outlet of the primary settling tank 5 is connected to SO via a seventh pipeline L72Liquid inlet of the desorption column 6. SO (SO)2The liquid outlet of the desorption tower 6 is connected to the wastewater collection tank 7 via an eighth conduit L8. The liquid outlet of the acid making system 4 is connected to the concentrated sulfuric acid diluter 8 via a concentrated sulfuric acid conveying pipeline Lc, and a second process water conveying pipeline LdIs connected to a concentrated sulfuric acid diluter 8. The liquid outlet of the concentrated sulfuric acid diluter 8 is connected to the liquid inlet of the wastewater collection tank 7 via a ninth conduit L9.
Example 2
Example 1 was repeated except that the compressed air supply line Le was connected to the gas inlet of the waste water collection tank 7.
Example 3
Example 2 was repeated except that the bottom liquid outlet of the primary settling tank 5 was connected to the liquid inlet of the wastewater collection tank 7 via a tenth pipe L10. An eleventh pipe L11 branches off from the tenth pipe L10, and the eleventh pipe L11 is connected to the sludge storage tank 9.
Example 4
Example 3 is repeated, except that a twelfth line L12 leading from the waste gas outlet of the waste water collecting tank 7 is connected to the SO2A gas inlet of the desorption column 6. SO (SO)2The gas outlet of the desorption tower 6 is connected to the first conduit L1 via a thirteenth conduit L13. The air delivery duct Lf is connected to a twelfth duct L12.
Example 5
Example 4 was repeated except that a fourteenth line L14 was branched from the seventh line L7, and the fourteenth line L14 was connected to the upper liquid inlet of the primary washing column 1. A fifteenth conduit L15 branches off from the fifth conduit L5, and a fifteenth conduit L15 is connected to the upper liquid inlet of the secondary scrubber 2. A sixteenth line L16 branches off from the fourth line L4, and a sixteenth line L16 is connected to the upper liquid inlet of the third washing column 3.
Example 6
As shown in FIG. 1, an external circulation cleaning and treating method for cyanogen-containing SRG gas, using the system of example 5, comprises the following steps:
1) the SRG gas containing cyanogen enters a first-stage washing tower 1 from the lower part, the SRG gas sequentially passes through the first-stage washing tower 1, a second-stage washing tower 2 and a third-stage washing tower 3, the SRG gas is respectively in countercurrent contact with washing solutions in the towers, and the washed gas is discharged from the top of the third-stage washing tower 3.
Wherein the temperature of the SRG gas entering the primary scrubber 1 is 400 ℃. The temperature of the gas entering the secondary washing column 2 was 80 ℃. The temperature of the gas entering the third washing column 3 was 40 ℃. The temperature of the gas discharged from the tertiary washing tower 3 was 30 ℃.
2) And gas discharged from the top of the third-stage washing tower 3 enters an acid making system 4 to make acid, so that concentrated sulfuric acid is obtained.
3) The process water enters a third-stage washing tower 3 from the bottom, the process water washes and purifies the cyanogen-containing SRG gas through the third-stage washing tower 3, a second-stage washing tower 2 and a first-stage washing tower 1 in sequence, the wastewater in the first-stage washing tower 1 after washing and purification is discharged to a primary settling tank 5, and the wastewater on the upper part of the primary settling tank 5 enters SO2And a desorption tower 6. SO (SO)2 Desorption tower 6 for removing SO physically dissolved in wastewater2And then discharges the wastewater to the wastewater collection tank 7.
Wherein the pH value of the liquid entering the three-stage washing tower 3 is 6, and the temperature is 30 ℃. The liquid entering the secondary washing column 2 had a pH of 3 and a temperature of 50 ℃. The pH of the liquid entering the first washing column 1 was 2.5 and the temperature was 60 ℃. The pH of the liquid discharged from the primary washing column 1 was 5 and the temperature was 80 ℃. The concentration of suspended matters in the wastewater at the upper part of the primary settling tank 5 is 3 mg/L.
4) Conveying the process water and the concentrated sulfuric acid prepared in the step 2) into a concentrated sulfuric acid diluter 8 for mixing to obtain dilute sulfuric acid. Dilute sulfuric acid is introduced into a wastewater collection tank 7, the dilute sulfuric acid reacts with wastewater, and acidic washing wastewater is discharged after the reaction.
Wherein, the amount of the dilute sulfuric acid introduced into the wastewater collection tank 7 is that the ratio of the molar weight of hydrogen ions in the dilute sulfuric acid to the molar weight of sulfite ions in the wastewater is 1: 0.4. The concentration of sulfuric acid in the dilute sulfuric acid is 60%. The pH value of the acid washing wastewater after the reaction of the dilute sulfuric acid and the wastewater is 2. The concentration of the suspended matter in the wastewater collection tank 7 was 1600 mg/L.
Example 7
Example 6 was repeated except that the method included: 5) using the concentrated sulfuric acid prepared in the step 2) for sale.
Example 8
Example 7 was repeated except that in step 4), compressed air was introduced into the waste water collection tank 7 while reacting dilute sulfuric acid with waste water.
Example 9
Example 8 was repeated except that in step 3), the waste water in the lower part of the primary precipitation tank 5 was passed into the waste water collection tank 7. The waste water at the lower part of the primary sedimentation tank 5 is also introduced into a sludge storage tank 9.
Example 10
Example 9 was repeated except that in step 1), the gas discharged from the primary washing column 1 was reacted with SO2The sulfur-containing gas generated by the desorption tower 6 is converged and then enters the second-stage washing tower 2 for washing and purification. In the step 4), introducing SO into the waste gas after the reaction of dilute sulfuric acid and waste water2And a desorption tower 6.
Example 11
Example 10 was repeated except that in step 3), a part of the wastewater in the upper part of the primary settling tank 5 overflowed to SO2The other part overflows to the first-stage washing tower 1 through the desorption tower 6. In the step 3), a part of the process water entering the third-stage washing tower 3 is recycled in the third-stage washing tower 3, and the other part of the process water enters the second-stage washing tower 2. A part of the process water entering the second-stage washing tower 2 from the third-stage washing tower 3 is recycled in the second-stage washing tower 2, and the other part of the process water enters the first-stage washing tower 1.
Example 12
Example 11 is repeated, except that in step 3), SO is removed from the waste water2To SO2Air is introduced into the desorption tower 6.
Experiments were conducted according to the external circulation cleaning treatment method for cyanogen-containing SRG gas provided in this example. The amount of wastewater, the concentration of suspended matters in the wastewater, (sulfuric acid, sulfite) salt concentration, chloride ion concentration, and sulfuric acid yield before the process of this example were measured. The amount of wastewater, the concentration of suspended matter in the wastewater, (sulfuric acid, sulfite) salt concentration, chloride ion concentration, and sulfuric acid yield after the process described in this example were then measured.
Detecting the index Before the process of this example was used After the process of the embodiment is adopted
Amount of waste water, m3/h 4 5
Concentration of suspended matter in g/L 3.2 0.1
(sulfuric acid, sulfurous acid) salt concentration, g/L 238 197
Concentration of chloride ion, g/L 40 42
Sulfuric acid yield, t/d 32 39.61

Claims (13)

1. An external circulation cleaning treatment method of cyanogen-containing SRG gas comprises the following steps:
1) the method comprises the following steps that (1) cyanogen-containing SRG gas enters a first-stage washing tower (1) from the lower part, the SRG gas sequentially passes through the first-stage washing tower (1), a second-stage washing tower (2) and a third-stage washing tower (3), the SRG gas is in countercurrent contact with washing solutions in the towers respectively, and the washed gas is discharged from the top of the third-stage washing tower (3);
2) gas discharged from the top of the three-stage washing tower (3) enters an acid making system (4) to make acid, so that concentrated sulfuric acid is obtained;
3) the process water enters a three-stage washing tower (3) from the bottom, the process water washes and purifies the cyanogen-containing SRG gas through the three-stage washing tower (3), a two-stage washing tower (2) and a one-stage washing tower (1) in sequence, the wastewater in the one-stage washing tower (1) after washing and purification is discharged to a primary settling tank (5), and the wastewater on the upper part of the primary settling tank (5) enters SO2A desorption tower (6); SO (SO)2Desorption tower (6) for removing the physically dissolved SO in the wastewater2Then discharging the wastewater to a wastewater collection tank (7);
4) conveying the process water and the concentrated sulfuric acid prepared in the step 2) into a concentrated sulfuric acid diluter (8) for mixing to obtain dilute sulfuric acid; and (3) introducing dilute sulfuric acid into a wastewater collection tank (7), reacting the dilute sulfuric acid with wastewater, and discharging acidic washing wastewater after reaction.
2. The method of claim 1, wherein: the method comprises the following steps: 5) using the concentrated sulfuric acid prepared in the step 2) for selling;
preferably, in the step 4), when the dilute sulfuric acid reacts with the wastewater, compressed air is introduced into the wastewater collection tank (7); and/or
In the step 3), the wastewater at the lower part of the primary sedimentation tank (5) is introduced into a wastewater collection tank (7); preferably, the waste water at the lower part of the primary sedimentation tank (5) is also introduced into a sludge storage tank (9).
3. The method according to claim 1 or 2, characterized in that: in the step 1), SRG gas passes through a first-stage washing tower (1) and then is mixed with SO2The sulfur-containing gas generated by the desorption tower (6) is converged and then enters the secondary washing tower (2) for washing and purification; preferably, in the step 4), the waste gas after the reaction of the dilute sulfuric acid and the waste water is introduced into SO2A desorption tower (6); and/or
In step 3), SO in the wastewater is removed2To SO2Air is introduced into the desorption tower (6).
4. The method according to any one of claims 1-3, wherein: in the step 3), part of the wastewater at the upper part of the primary settling tank (5) enters SO2The other part of the desorption tower (6) is introduced into the first-stage washing tower (1); and/or
In the step 3), part of the process water entering the third-stage washing tower (3) is recycled in the third-stage washing tower (3), and the other part of the process water enters the second-stage washing tower (2); one part of the process water entering the secondary washing tower (2) from the third washing tower (3) is recycled in the secondary washing tower (2), and the other part of the process water enters the first washing tower (1).
5. The method according to any one of claims 1-4, wherein: in the step 4), the pH value of the acidic washing wastewater after the reaction of the dilute sulfuric acid and the wastewater is 0-3, preferably 0.5-2.5, and more preferably 1-2;
preferably, in the step 4), the amount of the dilute sulfuric acid introduced into the wastewater collection tank (7) is that the ratio of the molar amount of the hydrogen ions in the dilute sulfuric acid to the molar amount of the sulfite ions in the wastewater is 1:0.1-1, preferably 1:0.2-0.6, and more preferably 1: 0.3-0.5;
preferably, the concentration of the sulfuric acid in the dilute sulfuric acid is 30-80%, preferably 40-70%, and more preferably 50-60%.
6. The method according to any one of claims 1-5, wherein: in the step 3), the pH value of the liquid entering the third-stage washing tower (3) is 5-7, preferably 5.5-6.5; and/or
In the step 3), the pH value of the liquid entering the secondary washing tower (2) is 3-5, preferably 3.5-4.5; and/or
In the step 3), the pH value of the liquid entering the primary washing tower (1) is 2-4, preferably 2.5-3.5; and/or
In the step 3), the pH value of the liquid discharged from the first-stage washing tower (1) is 4-6, preferably 4.5-5.5.
7. The method according to any one of claims 1-6, wherein: in the step 1), the temperature of the SRG gas entering the first-stage washing tower (1) is 250-480 ℃, preferably 300-450 ℃, and more preferably 380-430 ℃; and/or
In the step 1), the temperature of the gas entering the secondary washing tower (2) is 50-150 ℃, and preferably 70-100 ℃; and/or
In the step 1), the temperature of the gas entering the third-stage washing tower (3) is 10-80 ℃, and preferably 30-60 ℃; and/or
In the step 1), the temperature of the gas discharged from the third-stage washing tower (3) is 10-60 ℃, and preferably 20-40 ℃.
8. The method according to any one of claims 1-7, wherein: in the step 3), the temperature of the liquid entering the third-stage washing tower (3) is 10-60 ℃, and preferably 20-40 ℃; and/or
In the step 3), the temperature of the liquid entering the secondary washing tower (2) is 10-80 ℃, and preferably 30-60 ℃; and/or
In the step 3), the temperature of the liquid entering the first-stage washing tower (1) is 30-100 ℃, and preferably 50-80 ℃; and/or
In the step 3), the temperature of the liquid discharged from the primary washing tower (1) is 50-120 ℃, and preferably 70-90 ℃.
9. The method according to any one of claims 1-8, wherein: the concentration of suspended matters in the wastewater collection tank (7) is 600-2500 mg/L, preferably 800-2300 mg/L; and/or
In the step 3), the concentration of suspended matters in the wastewater at the upper part of the primary settling tank (5) is 0-100 mg/L, preferably 1-80 mg/L, and more preferably 2-50 mg/L.
10. A system for clean remediation of cyanogen-containing SRG gas using the method of any of claims 1 to 9, the system comprising: a first-stage washing tower (1), a second-stage washing tower (2), a third-stage washing tower (3), an acid making system (4), a primary settling tank (5), SO2A desorption tower (6), a waste water collecting tank (7) and a concentrated sulfuric acid diluter (8); SRG gas transmission pipeline (L)a) A gas inlet connected to the primary scrubber (1), a gas outlet of the primary scrubber (1) being connected to a gas inlet of the secondary scrubber (2) via a first conduit (L1), a gas outlet of the secondary scrubber (2) being connected to a gas inlet of the tertiary scrubber (3) via a second conduit (L2), a gas outlet of the tertiary scrubber (3) being connected to the acid production system (4) via a third conduit (L3); and
first process water conveying pipeline (L)b) Is connected to the bottom liquid inlet of the third washing tower (3), the liquid outlet of the third washing tower (3) is connected to the lower liquid inlet of the second washing tower (2) via a fourth pipeline (L4), the liquid outlet of the second washing tower (2) is connected to the lower liquid inlet of the first washing tower (1) via a fifth pipeline (L5), the liquid outlet of the first washing tower (1) is connected to the primary settling tank (5) via a sixth pipeline (L6), the upper liquid outlet of the primary settling tank (5) is connected to SO 7 via a seventh pipeline (L7)2A liquid inlet of the desorption column (6); SO (SO)2The liquid outlet of the desorption tower (6) is connected to the waste water collecting tank (7) through an eighth pipeline (L8); the liquid outlet of the acid making system (4) is connected to the concentrated sulfuric acid diluter (8) through a concentrated sulfuric acid conveying pipeline (Lc), and a second conveying pipeline (L) for process waterd) Is connected to a concentrated sulfuric acid diluter (8); the liquid outlet of the concentrated sulfuric acid diluter (8) is connected to the liquid inlet of the wastewater collection tank (7) via a ninth conduit (L9).
11. The system of claim 10, wherein: the compressed air conveying pipeline (Le) is connected to a gas inlet of the waste water collecting tank (7); and/or
Preferably, the bottom liquid outlet of the primary settling tank (5) is connected to the liquid inlet of the wastewater collection tank (7) via a tenth conduit (L10); preferably, an eleventh pipeline (L11) branches off from the tenth pipeline (L10), and the eleventh pipeline (L11) is connected to the sludge storage tank (9).
12. The system according to claim 10 or 11, characterized in that: a twelfth conduit (L12) leading from the waste gas outlet of the waste water collecting tank (7) is connected to the SO2A gas inlet of the desorption column (6); SO (SO)2The gas outlet of the desorption column (6) is connected to the first conduit (L1) via a thirteenth conduit (L13);
preferably, the air delivery duct (Lf) is connected to the twelfth duct (L12).
13. The system according to any one of claims 10-12, wherein: a fourteenth pipeline (L14) branches off from the seventh pipeline (L7), and the fourteenth pipeline (L14) is connected to the upper liquid inlet of the primary washing tower (1); and/or
A fifteenth line (L15) branches off from the fifth line (L5), the fifteenth line (L15) being connected to the upper liquid inlet of the secondary washing column (2); a sixteenth line (L16) branches off from the fourth line (L4), the sixteenth line (L16) being connected to the upper liquid inlet of the tertiary scrubber tower (3).
CN202010779000.1A 2020-08-05 2020-08-05 External circulation cleaning treatment method and system for cyanogen-containing SRG gas Active CN114053834B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010779000.1A CN114053834B (en) 2020-08-05 2020-08-05 External circulation cleaning treatment method and system for cyanogen-containing SRG gas

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010779000.1A CN114053834B (en) 2020-08-05 2020-08-05 External circulation cleaning treatment method and system for cyanogen-containing SRG gas

Publications (2)

Publication Number Publication Date
CN114053834A true CN114053834A (en) 2022-02-18
CN114053834B CN114053834B (en) 2024-01-02

Family

ID=80232189

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010779000.1A Active CN114053834B (en) 2020-08-05 2020-08-05 External circulation cleaning treatment method and system for cyanogen-containing SRG gas

Country Status (1)

Country Link
CN (1) CN114053834B (en)

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5690899A (en) * 1995-07-29 1997-11-25 Lentjes Bischoff Gmbh Process for removing sulphur dioxide from flue gas
CN1600410A (en) * 2003-09-24 2005-03-30 北京国纬达环保科技有限公司 Integration method for ammonia process of desulfurizing flue gas and multiple utilizing desulfurized products and equipment
CN101723411A (en) * 2009-12-18 2010-06-09 聊城鲁西化工第五化肥厂 Process and equipment for producing potassium sulfate compound fertilizer by integrally utilizing tail gas generated in sulphuric acid production
CN201930584U (en) * 2010-12-29 2011-08-17 攀钢集团钢铁钒钛股份有限公司 Sedimentation tower
CN108939767A (en) * 2018-07-13 2018-12-07 中冶长天国际工程有限责任公司 A method of the purification of the wet high-effective of flue gas containing elemental sulfur
CN109499289A (en) * 2018-11-07 2019-03-22 襄阳泽东化工集团有限公司 A kind of processing method and processing device of desulfidation tail gas
CN110124507A (en) * 2018-02-02 2019-08-16 中冶长天国际工程有限责任公司 A kind of method and device thereof of multi-pollutant flue gas cleaning treatment

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5690899A (en) * 1995-07-29 1997-11-25 Lentjes Bischoff Gmbh Process for removing sulphur dioxide from flue gas
CN1600410A (en) * 2003-09-24 2005-03-30 北京国纬达环保科技有限公司 Integration method for ammonia process of desulfurizing flue gas and multiple utilizing desulfurized products and equipment
CN101723411A (en) * 2009-12-18 2010-06-09 聊城鲁西化工第五化肥厂 Process and equipment for producing potassium sulfate compound fertilizer by integrally utilizing tail gas generated in sulphuric acid production
CN201930584U (en) * 2010-12-29 2011-08-17 攀钢集团钢铁钒钛股份有限公司 Sedimentation tower
CN110124507A (en) * 2018-02-02 2019-08-16 中冶长天国际工程有限责任公司 A kind of method and device thereof of multi-pollutant flue gas cleaning treatment
CN108939767A (en) * 2018-07-13 2018-12-07 中冶长天国际工程有限责任公司 A method of the purification of the wet high-effective of flue gas containing elemental sulfur
CN109499289A (en) * 2018-11-07 2019-03-22 襄阳泽东化工集团有限公司 A kind of processing method and processing device of desulfidation tail gas

Also Published As

Publication number Publication date
CN114053834B (en) 2024-01-02

Similar Documents

Publication Publication Date Title
CN110127918B (en) Zero-discharge treatment method and device for acidic flue gas washing wastewater
TWI751430B (en) Acid gas treatment
CN110124507B (en) Method and device for cleaning and treating multi-pollutant flue gas
CN107774082B (en) Method and device for flue gas desulfurization
CN112403186B (en) Method for cooperatively treating and recycling multi-pollutant flue gas and ferrous ammonium sulfite
CN108975570A (en) A kind of device and method handling industrially desulfurized waste water using stack gases
CN110745989B (en) Activated carbon flue gas purification acid-making wastewater zero-discharge process and system
CN103936189A (en) Processing method for recovery processing of high ammonia nitrogen wastewater
CN105348145A (en) Method for producing by-product cyclohexanone-oxime through flue gas desulphurization by ammonia method
CN114053839B (en) Method and system for cleaning and treating cyanide-containing SRG gas and purifying tail gas of hot blast stove
CN204619726U (en) Copper making ring collection flue gas desulfur device
CN106268241A (en) Copper making ring collection fume desulphurization method and device
CN114053834B (en) External circulation cleaning treatment method and system for cyanogen-containing SRG gas
CN114053840B (en) Internal circulation cleaning treatment method and system for cyanide-containing SRG gas
CN112299626A (en) Method for purifying flue gas at tail of sintering machine and cooperatively treating waste water
CN102688677B (en) Method for enhancing total mercury recovery rate of metallurgical fume by reducing bivalent mercury
CN216062697U (en) Inside and outside bucket self-loopa airlift wet flue gas desulfurization device
CN214437868U (en) Two-stage tandem type alkali washing treatment equipment for copper smelting waste gas
CN101703878A (en) Smoke discharging device and method
CN211770758U (en) Sintering machine tail gas cleaning and waste water concurrent processing system
CN112295385B (en) Tail gas purification and waste heat utilization method and device of hot blast stove for active carbon desorption
CN209193691U (en) A kind of equipment handling industrially desulfurized waste water using stack gases
CN111282436A (en) Purification process and system for waste gas containing high-concentration reductive sulfide in sewage station
CN115180753B (en) Method for catalyzing and desalting SRG washing wastewater and system for catalyzing and desalting SRG washing wastewater
CN107789953B (en) Method and device for flue gas desulfurization

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant