CN107803108B - Deep purification method for tail gas emitted by tissue in aluminum electrolysis production process - Google Patents
Deep purification method for tail gas emitted by tissue in aluminum electrolysis production process Download PDFInfo
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- B01D53/34—Chemical or biological purification of waste gases
- B01D53/46—Removing components of defined structure
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- B01D53/34—Chemical or biological purification of waste gases
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- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
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Abstract
A method for deeply purifying tail gas emitted by tissue in the aluminum electrolysis production process comprises the following steps: (1) leading the tail gas with organized emission into a moving bed filled with gamma-alumina, and carrying out deep defluorination through the gamma-alumina; (2) simultaneously blowing the defluorinated tail gas and ozone into a desulfurization reactor filled with zinc oxide slurry, and under the action of ozone and stirring conditions, removing SO in the defluorinated tail gas2Reacting with zinc oxide to generate zinc sulfate, and performing desulfurization reaction on the zinc sulfate to form a zinc sulfate solution in water; (3) heating, evaporating, concentrating, filtering and drying the discharged zinc sulfate solution to obtain a zinc sulfate heptahydrate product; (4) introducing a calcium ion-containing solution into a water inlet of the Venturi jet reactor, simultaneously introducing desulfurization tail gas for mineralization reaction, and discharging decarburization tail gas from a gas outlet. The method of the invention prepares zinc sulfate heptahydrate and calcium carbonate products, and recovers SO in the aluminum electrolysis tail gas2、CO2The resource solves the pollution problem of the waste carbide slag slurry, and greatly reduces the flue gas treatment cost.
Description
Technical Field
The invention belongs to the technical field of metallurgy and environmental protection, and particularly relates to a method for deeply purifying tail gas emitted by an organization in an aluminum electrolysis production process.
Background
In the process of aluminum electrolysis, the carbon anode and alumina generate electrochemical reaction in the cryolite melt to generate a certain amount of SO2、CO2And containing fluorine and Al2O3The smoke of the dust is collected by a gas collecting hood at the upper part of the aluminum electrolytic cell and then is discharged from a chimney through the purification treatment of a smoke discharging system and a device, and the aluminum electrolytic smoke is generally called primary smoke and is also called organized discharge smoke; at present, the fluoride in the organized emission of aluminum electrolysis is mainly removed by dry purification in China, but SO in flue gas2And CO2No relevant purge recovery measures are taken. With the gradual increase of the use amount of high-sulfur petroleum coke in the production of prebaked anode, SO in the aluminum electrolysis exhaust flue gas of part of enterprises2The concentration of the active carbon reaches 200-600 mg/Nm3Exceeding the new environmental standard limit value; the new aluminum industry pollutant emission standard (GB25465-2010) is regulated by a repair order, and the fluoride emission limit value of the aluminum electrolysis industry in partial regions is 3mg/Nm3，SO2Is 100mg/Nm3The existing purification process is difficult to reach the new emission standard, and the problem of overproof fluorine and sulfur in the tail gas discharged by dry purification is solved.
Electrolytic aluminium is CO in nonferrous smelting industry2The industry with the largest emission, the emission per year is more than 6000 million tons, and the emission accounts for CO in China24% of the discharge amount is undoubtedly a 'huge carbon source'; large amount of CO2The global "greenhouse effect" caused by the gas emission and a serious environmental problem have attracted the attention of all countries in the world, and the gas emission is regarded as the key point of greenhouse gas reduction and control. Therefore, the research of the aluminum electrolysis organized emission tail gas deep purification, defluorination and desulfurization process needs to consider recycling CO in the flue gas2To realize the true aluminum electrolysis industryEnergy conservation and emission reduction are achieved, so that the method is beneficial to the healthy and sustainable development of the aluminum electrolysis industry.
Disclosure of Invention
Aiming at the problem of organized exhaust of flue gas in the existing aluminum electrolysis production process, the invention provides a method for deeply purifying organized exhaust in the aluminum electrolysis production process, which comprises the steps of deeply removing HF, and absorbing SO by using zinc oxide slurry2And forcibly oxidized to obtain ZnSO4Separating the solution from zinc oxide, concentrating to produce ZnSO4·7H2O, simultaneous CO capture2The light calcium carbonate is obtained, and various beneficial elements are comprehensively utilized while pollution is reduced.
The method of the invention is carried out according to the following steps:
(1) leading the tail gas with organized emission into a moving bed filled with gamma-alumina, and carrying out deep defluorination by the gamma-alumina to form defluorinated tail gas after the deep defluorination; wherein the tail gas discharged by the organization enters from the lower part of the moving bed and flows upwards, the gamma-alumina moves from top to bottom in the moving bed, the flow velocity of the tail gas discharged by the organization is controlled to be 0.1-3 m/s, the moving velocity of the gamma-alumina is controlled to be 0.01-0.04 m/h, and the solid-gas ratio is controlled to be 25-40 g/m3；
(2) Simultaneously spraying the defluorinated tail gas and ozone into a desulfurization reactor filled with zinc oxide slurry, wherein the zinc oxide slurry consists of water and zinc oxide, and the zinc oxide accounts for 10-20% of the total weight of the water under the initial condition; under the action of ozone and stirring condition, removing SO from tail gas2Reacting with zinc oxide to generate zinc sulfate, and performing desulfurization reaction on the zinc sulfate to form a zinc sulfate solution in water; the residual gas after the desulfurization reaction forms desulfurization tail gas to be discharged; when the concentration of the zinc sulfate solution in the reaction tank reaches 150-300 g/L, discharging 1/3-1/4 of the whole zinc sulfate solution in the reactor; the mass flow ratio of the ozone to the defluorinated tail gas is 1: 3;
(3) heating the discharged zinc sulfate solution, evaporating and concentrating, cooling to 25 +/-1 ℃ under the condition of water bath when crystals are separated out, preserving heat for 10-60 min, filtering to obtain a crystalline solid phase and a filtrate, and drying the obtained crystalline solid phase at 40-50 ℃ to remove non-crystalline water to obtain zinc sulfate heptahydrate;
(4) introducing a calcium ion-containing solution into a water inlet of the Venturi jet reactor, wherein the calcium ion concentration of the calcium ion-containing solution is 1.0-2.0 g/L; simultaneously introducing the desulfurization tail gas into an air inlet of the Venturi jet reactor, mixing the desulfurization tail gas with a calcium ion-containing solution for mineralization reaction, and trapping CO in the desulfurization tail gas2(ii) a The injection pressure of the calcium ion-containing solution is 0.5-2.0 MPa, and the injection pressure of the desulfurization tail gas is 0.2-1.2 MPa; reaction ore pulp containing calcium carbonate solid particles is obtained at the water outlet of the Venturi jet reactor, and decarbonized tail gas is discharged from the gas outlet.
The solid-gas ratio refers to the weight ratio of gamma-alumina to the volume ratio of the organized exhaust emission.
The purity of the gamma-alumina is more than or equal to 98 percent, and the specific surface area is 200-350 m2A pore volume of 0.4 to 0.46cm3/g。
The discharging of 1/3-1/4 of the whole zinc sulfate solution is discharged through a filtering device in the desulfurization reactor.
The concentration of HF in the organized exhaust tail gas is 1.2-6 mg/Nm3，SO2The concentration of (A) is 250-1000 mg/Nm3，CO2The concentration of (A) is 8000-13000 mg/Nm3。
Concentration of HF in the above-mentioned defluorinated exhaust gas<0.001mg/Nm3SO in desulfurized tail gas2Concentration of (2)<20mg/Nm3CO in the decarbonized tail gas2The concentration of (A) is 350-600 mg/Nm3。
The reaction ore pulp is dried and dehydrated to obtain calcium carbonate, the purity is more than or equal to 98.0 percent, and the whiteness is more than or equal to 85.0 percent.
The calcium ion-containing solution is a filtrate obtained by dissolving and filtering waste carbide slag and is used as the calcium ion-containing solution.
The decarbonized tail gas is directly discharged.
In the method, the heat generated in the reaction process of the Venturi jet reactor is taken out from the reaction ore pulp, and is subjected to heat exchange through the heat exchanger to be used as a heat source for evaporation concentration, heat preservation and drying of the zinc sulfate solution.
In the step (2), after 1/3-1/4 of all zinc sulfate solution is filtered and discharged, zinc oxide and water are supplemented into the desulfurization reactor to initial conditions, and then the desulfurization reaction is continued; the water comprises the filtrate of the step (3).
The desulfurization reactor comprises a closed shell, and a stirring paddle and a filtering device which are arranged in the closed shell, wherein the top of the shell is provided with a feed inlet and an air outlet, and the bottom of the shell is provided with an ozone inlet and a defluorinated tail gas inlet; wherein the filter device is fixed on the side wall of the shell; the filtering device consists of a filter screen and a filter shell, the filter shell is fixed with the shell, the filter screen and a part of the shell enclose a filtering cavity, and the side wall of the shell is provided with a liquid discharge port for communicating the filtering cavity with the outside of the shell; the ozone inlet and the defluorination tail gas inlet are respectively communicated with the ozone cavity and the tail gas cavity, and gas distributors are respectively arranged above the ozone cavity and the tail gas cavity.
The stirring paddle is composed of an upper SSB-D stirring paddle and a lower Intermig stirring paddle which are coaxial.
The decarbonized tail gas generated by the method is far lower than the existing emission standard, the ultralow emission of flue gas is realized, the problem that fluorine and sulfur in the defluorinated tail gas purified by the current aluminum electrolysis organized emission dry method exceed the standard is solved, and CO in the tail gas is mineralized and trapped2The carbon emission of the aluminum electrolysis is greatly reduced, and the tail gas emitted by the current aluminum electrolysis organized emission is further purified and defluorinated deeply so as to reduce the pressure of the traditional dry purification; the invention adopts a counter-flow dry moving bed, utilizes high-activity gamma-alumina to further purify and remove HF in tail gas deeply, improves the defluorination effect of the whole system, and reduces the corrosion of hydrogen fluoride to equipment in the subsequent wet desulphurization process; the defluorinated alumina can be directly returned to the aluminum electrolysis system.
In the invention, zinc oxide and SO are added in a zinc oxide desulfurization reactor2The reaction and direct oxidation generate soluble zinc sulfate, thereby preventing equipment scaling and pipeline blockage; the zinc sulfate product can be directly sold, the economic value is considerable, and the high-valued recycling of waste gas is realized; after preliminary budget, 1 ton of SO is processed2Can produce about 4 tons of zinc sulfate products, and has direct economic benefit of about 3000 yuan/ton SO2；SO2Gas-liquid-solid in the absorption processThree phases are fully dispersed and mixed, SO that the high-efficiency dissolution of zinc oxide in a liquid phase and the micronization distribution of bubbles of tail gas and ozone in the liquid phase are realized, and the improvement on the utilization rate of zinc oxide and the improvement on SO2The absorption rate of (a); further mineralizing and trapping CO in desulfurized tail gas by using waste carbide slag in PVC (polyvinyl chloride) industry2Preparing a light calcium carbonate product with high added value; solves the pollution problem of waste carbide slag slurry in PVC industry, and effectively recovers CO in the aluminum electrolysis tail gas2Resource, forming an integrated technology of defluorination, desulfurization and decarburization for the tail gas exhausted by the aluminum electrolysis organized mode; the system is provided with a heat exchanger for obtaining heat generated in the desulfurization and decarburization processes, and the system can be used for the evaporation crystallization process of zinc sulfate solution, thereby greatly reducing the flue gas treatment cost.
Drawings
FIG. 1 is a schematic flow chart of a method for deeply purifying tail gas discharged by an organization in an aluminum electrolysis production process according to an embodiment of the present invention;
FIG. 2 is a schematic view of a desulfurization reactor in an embodiment of the present invention; in the figure, 1, a shell, 2, a stirring shaft, 3, an SSB-D stirring paddle, 4, an intermixg stirring paddle, 5, a filter screen, 6, a filter shell, 7, a filter cavity, 8, a feed inlet, 9, an air outlet, 10, an ozone inlet, 11, a defluorination tail gas inlet, 12, an ozone cavity, 13, a defluorination tail gas cavity, 14, a gas distributor, 15, zinc oxide slurry, 16 and a liquid discharge port.
Detailed Description
In the embodiment of the invention, the desulfurization tail gas is introduced into the Venturi jet reactor, and when the desulfurization tail gas is mixed with the calcium ion-containing solution in the Venturi jet reactor, the flow rate of the calcium ion-containing solution is 50-350 m3/h。
In the embodiment of the invention, the content of the decarbonized tail gas, the content of the defluorinated tail gas and the content of HF are detected on line, and the type of detection equipment is JC-5Q pump suction type five-in-one (SO)2、O2、CO2NO, HF) flue gas analyzer.
In the embodiment of the invention, the concentration of zinc sulfate in the desulfurization reactor adopts MPR E-Scan-ZnSO4And (4) detecting the zinc sulfate concentration on line by using a zinc sulfate concentration detector.
The moving bed adopted in the embodiment of the invention is a counter-flow moving bed, alumina is quantitatively added from the top of the moving bed through a star-shaped feeder at a constant speed, gas enters from the bottom of the moving bed, the flow rate of the gas is controlled to be 0.1-3 m/s, the moving speed of the alumina is 0.01-0.04 m/h, the alumina and the moving bed are in full contact, internal components in various shapes are arranged in the moving bed, the pressure drop of the bed layer is reduced, and a bell mouth discharging device is designed at the bottom to realize the continuous discharging of the alumina.
The desulfurization reactor structure adopted in the embodiment of the invention is shown in figure 2, and comprises a closed shell 1, an upper SSB-D stirring paddle 3 fixed on the same stirring shaft 2, a lower intermix stirring paddle 4 and a filtering device, wherein the top of the shell 1 is provided with a feed inlet 8 and an air outlet 9, and the bottom of the shell 1 is provided with an ozone inlet 10 and a defluorination tail gas inlet 11; the filtering device is fixed on the side wall of the shell 1; the filtering device consists of a filter screen 5 and a filter shell 6, the filter shell 6 is fixed with the shell 1, the filter shell 6, the filter screen 5 and a part of the shell 1 enclose a filtering cavity 7, and the side wall of the shell 1 is provided with a liquid outlet 16 for communicating the filtering cavity 7 with the outside of the shell 1; the ozone inlet 10 and the defluorinated tail gas inlet 11 are respectively communicated with an ozone cavity 12 and a tail gas cavity 13, and a plurality of gas distributors 14 are respectively arranged above the ozone cavity 12 and the tail gas cavity 13.
The filter screen in the embodiment of the invention adopts a 316L stainless steel corrosion-resistant rigid screen with more than 300 meshes, and is made into an arc shape for trapping zinc oxide particles in the desulfurization reactor.
The SSB-D stirring paddle in the embodiment of the invention is an SSB-D mechanical stirring paddle improved on the basis of a cross paddle type and mentioned in 'numerical simulation research on behavior of bubbles in metallurgical solution'.
The Intermig stirring in the embodiment of the invention is a novel Intermig paddle mentioned in patent CN2848823Y, and the ratio of the paddle diameter to the groove diameter of the Intermig stirring paddle is 0.3-0.6, so that the suspension of the zinc oxide slurry is ensured.
The distance and the paddle diameter ratio of the Intermig stirring paddle to the SSB-D stirring paddle in the embodiment of the invention are 0.5-1.1.
The gas distributor in the embodiment of the invention is an annular gas distribution ring, the ratio of the diameter of the gas distribution ring to the inner diameter of the desulfurization reactor is 0.2-0.3, the diameter of each opening is 2-5 mm, and the opening is upwards formed; wherein the number ratio of the openings of the gas distributor of the defluorination tail gas cavity to the openings of the gas distributor of the ozone cavity is (2-3) to 1.
The ratio of the liquid level height of the zinc oxide slurry in the desulfurization reactor to the inner diameter of the desulfurization reactor in the embodiment of the invention is 1.2-1.6.
The use method of the desulfurization reactor in the embodiment of the invention comprises the following steps: blowing defluorinated tail gas and ozone at the bottom of a desulfurization reactor, adding zinc oxide slurry from an upper feeding port, suspending the zinc oxide slurry through a stirring paddle, smashing gas bubbles, micronizing the bubbles, and fully and uniformly mixing gas, liquid and solid phases; quantitatively discharging zinc sulfate solution from the desulfurization reactor through a liquid outlet, intercepting unreacted zinc oxide in the desulfurization reactor by a filter screen, discharging the reacted desulfurization tail gas from the top of the desulfurization reactor, and performing mineralization and CO capture2Provided is a system.
The Venturi jet reactor adopted in the embodiment of the invention is a multistage jet reaction device CO in patent CN103446868B2The mineralization capture system is formed by connecting three or more stages of jet reactors in series.
In the embodiment of the invention, the pH value of the calcium ion-containing solution is 12-13.
In the embodiment of the invention, the introduction speed of the defluorination tail gas blown into the desulfurization reaction tank is 10-12 m/s, the stirring speed is 150-350 rpm, and the ozone introduction speed is 2-5 g/h.
In the embodiment of the invention, the time of the desulfurization reaction is 10-15 h.
The purity of the gamma-alumina in the embodiment of the invention is more than or equal to 98%, and the specific surface area is 200-350 m2A pore volume of 0.4 to 0.46cm3/g。
Example 1
The concentration of HF in the tail gas discharged by the organization is 1.2mg/Nm3，SO2At a concentration of 1000mg/Nm3，CO2At a concentration of 8000mg/Nm3；
Leading the tail gas with organized emission into a moving bed filled with gamma-alumina, and carrying out deep defluorination by the gamma-alumina to form defluorinated tail gas after the deep defluorination; wherein there is an organized emission of exhaust gases fromThe lower part of the moving bed enters and flows upwards, the gamma-alumina moves from top to bottom in the moving bed, the flow velocity of tail gas discharged by the organization is controlled to be 3m/s, the moving velocity of the gamma-alumina is controlled to be 0.04m/h, and the solid-gas ratio is controlled to be 25g/m3(ii) a The solid-gas ratio refers to the ratio of the weight of the gamma-alumina to the volume of the tail gas emitted by the organization;
concentration of HF in defluorination tail gas<0.001mg/Nm3；
Simultaneously spraying defluorinated tail gas and ozone into a desulfurization reactor filled with zinc oxide slurry, wherein the zinc oxide slurry consists of water and zinc oxide, and the zinc oxide accounts for 20% of the total weight of the water under the initial condition; under the action of ozone and stirring condition, removing SO from tail gas2Reacting with zinc oxide to generate zinc sulfate, and performing desulfurization reaction on the zinc sulfate to form a zinc sulfate solution in water; the residual gas after the desulfurization reaction forms desulfurization tail gas to be discharged; when the concentration of the zinc sulfate solution in the reaction tank reaches 300g/L, discharging 1/3 of the whole zinc sulfate solution in the reactor; the mass flow ratio of the ozone to the defluorinated tail gas is 1: 3; after part of the zinc sulfate solution is discharged, supplementing zinc oxide and water into the desulfurization reactor to initial conditions, and then continuing the desulfurization reaction;
SO in desulfurized tail gas2Concentration of (3) 19mg/Nm3；
Heating the discharged zinc sulfate solution, evaporating and concentrating, when crystals are separated out, cooling to 25 +/-1 ℃ under the condition of water bath, preserving heat for 10min, then filtering to obtain a crystalline solid phase and filtrate, drying the obtained crystalline solid phase at 40 ℃ to remove non-crystalline water to obtain zinc sulfate heptahydrate, and analyzing to reach the industrial grade requirement; the filtrate is used for preparing zinc oxide slurry and returns to the desulfurization step;
introducing a calcium ion-containing solution into a water inlet of the Venturi jet reactor, wherein the calcium ion concentration of the calcium ion-containing solution is 1.0 g/L; simultaneously introducing the desulfurization tail gas into an air inlet of the Venturi jet reactor, mixing the desulfurization tail gas with a calcium ion-containing solution for mineralization reaction, and trapping CO in the desulfurization tail gas2(ii) a The injection pressure of the calcium ion-containing solution is 0.5MPa, and the injection pressure of the desulfurization tail gas is 0.2 MPa; obtaining reaction ore pulp containing calcium carbonate solid particles at the water outlet of the Venturi jet reactor, and discharging gasDischarging decarbonized tail gas from the outlet, and discharging the decarbonized tail gas into the atmosphere through a chimney; the calcium ion-containing solution is obtained by dissolving and filtering waste carbide slag (PVC carbide slag) to obtain filtrate as calcium ion-containing solution;
the heat generated by the Venturi jet reactor in the reaction process is taken out by the reaction ore pulp, and is subjected to heat exchange by the heat exchanger to be used as a heat source for evaporation concentration, heat preservation and drying of the zinc sulfate solution;
CO in decarbonization tail gas2At a concentration of 350mg/Nm3；
The reaction ore pulp is dried and dehydrated to obtain the light calcium carbonate, the purity is more than or equal to 98.0 percent, and the whiteness is more than or equal to 85.0 percent.
Example 2
The method is the same as example 1, except that:
(1) the concentration of HF in the tail gas discharged by the organization is 2.1mg/Nm3，SO2At a concentration of 780mg/Nm3，CO2At a concentration of 9000mg/Nm3；
(2) The gamma-alumina moves from top to bottom in the moving bed, the flow velocity of the tail gas discharged by the organization is controlled to be 2m/s, the moving velocity of the gamma-alumina is controlled to be 0.03m/h, and the solid-gas ratio is controlled to be 28g/m3；
(3) The initial condition of the desulfurization reactor is that zinc oxide accounts for 18 percent of the total weight of water; when the concentration of the zinc sulfate solution in the reaction tank reaches 260g/L, discharging 1/3 of the whole zinc sulfate solution in the reactor;
(4) SO in desulfurized tail gas2Concentration of 12mg/Nm3；
(5) Cooling to 25 + -1 deg.C in water bath, maintaining the temperature for 20min, and filtering to obtain crystalline solid phase, and drying at 45 deg.C;
(6) the calcium ion concentration of the calcium ion-containing solution is 1.5g/L, the injection pressure is 1.0MPa, and the injection pressure of the desulfurization tail gas is 0.4 MPa; CO in decarbonization tail gas2At a concentration of 400mg/Nm3。
Example 3
The method is the same as example 1, except that:
(1) the concentration of HF in the tail gas discharged by the organization is 3.3mg/Nm3，SO2At a concentration of 590mg/Nm3，CO2Has a concentration of 10000mg/Nm3；
(2) The gamma-alumina moves from top to bottom in the moving bed, the flow velocity of the tail gas discharged by the organization is controlled to be 1m/s, the moving velocity of the gamma-alumina is controlled to be 0.02m/h, and the solid-gas ratio is controlled to be 32g/m3；
(3) The initial condition of the desulfurization reactor is that zinc oxide accounts for 15 percent of the total weight of water; when the concentration of the zinc sulfate solution in the reaction tank reaches 220g/L, discharging 1/3 of the whole zinc sulfate solution in the reactor;
(4) SO in desulfurized tail gas2Concentration of (2) 10mg/Nm3；
(5) Cooling to 25 + -1 deg.C in water bath, keeping the temperature for 30min, and filtering to obtain crystalline solid phase, and drying at 45 deg.C;
(6) the calcium ion concentration of the calcium ion-containing solution is 1.5g/L, the injection pressure is 1.0MPa, and the injection pressure of the desulfurization tail gas is 0.6 MPa; CO in decarbonization tail gas2Has a concentration of 490mg/Nm3。
Example 4
The method is the same as example 1, except that:
(1) the concentration of HF in the tail gas discharged by the organization is 4.6mg/Nm3，SO2At a concentration of 380mg/Nm3，CO2At a concentration of 12000mg/Nm3；
(2) The gamma-alumina moves from top to bottom in the moving bed, the flow velocity of the tail gas discharged by the organization is controlled to be 0.5m/s, the moving velocity of the gamma-alumina is controlled to be 0.02m/h, and the solid-gas ratio is controlled to be 36g/m3；
(3) The initial condition of the desulfurization reactor is that zinc oxide accounts for 12 percent of the total weight of water; when the concentration of the zinc sulfate solution in the reaction tank reaches 180g/L, discharging 1/4 of the whole zinc sulfate solution in the reactor;
(4) SO in desulfurized tail gas2Concentration of 8mg/Nm3；
(5) Cooling to 25 + -1 deg.C in water bath, keeping the temperature for 40min, and filtering to obtain crystalline solid phase, and drying at 50 deg.C;
(6) the calcium ion concentration of the calcium ion-containing solution is 2.0g/L, the injection pressure is 1.5MPa, and the injection pressure of the desulfurization tail gas is 1.0 MPa; CO in decarbonization tail gas2At a concentration of 540mg/Nm3。
Example 5
The method is the same as example 1, except that:
(1) the concentration of HF in the tail gas discharged by the organization is 6mg/Nm3，SO2At a concentration of 250mg/Nm3，CO2Has a concentration of 13000mg/Nm3；
(2) The gamma-alumina moves from top to bottom in the moving bed, the flow velocity of the tail gas discharged by the organization is controlled to be 0.1m/s, the moving velocity of the gamma-alumina is controlled to be 0.01m/h, and the solid-gas ratio is controlled to be 40g/m3；
(3) The initial condition of the desulfurization reactor is that zinc oxide accounts for 10 percent of the total weight of water; when the concentration of the zinc sulfate solution in the reaction tank reaches 150g/L, discharging 1/4 of the whole zinc sulfate solution in the reactor;
(4) SO in desulfurized tail gas2Concentration of (3) 6mg/Nm3；
(5) Cooling to 25 + -1 deg.C in water bath, maintaining the temperature for 60min, and filtering to obtain crystalline solid phase, and drying at 50 deg.C;
(6) the calcium ion concentration of the calcium ion-containing solution is 2.0g/L, the injection pressure is 2.0MPa, and the injection pressure of the desulfurization tail gas is 1.2 MPa; CO in decarbonization tail gas2At a concentration of 600mg/Nm3。
Claims (2)
1. A method for deeply purifying tail gas emitted by tissue in the aluminum electrolysis production process is characterized by comprising the following steps:
(1) leading the tail gas with organized emission into a moving bed filled with gamma-alumina, and carrying out deep defluorination by the gamma-alumina to form defluorinated tail gas after the deep defluorination; wherein the tail gas discharged by the organization enters from the lower part of the moving bed and flows upwards, the gamma-alumina moves from top to bottom in the moving bed, the flow velocity of the tail gas discharged by the organization is controlled to be 0.1-3 m/s, the moving velocity of the gamma-alumina is controlled to be 0.01-0.04 m/h, and the solid-gas ratio is controlled to be 25-40 g/m3(ii) a The purity of the gamma-alumina is more than or equal to 98 percent, and the specific surface area is 200-350 m2A pore volume of 0.4 to 0.46cm3(ii)/g; the concentration of HF in the organized exhaust tail gas is 1.2-6 mg/Nm3，SO2The concentration of (A) is 250-1000 mg/Nm3，CO2The concentration of (A) is 8000-13000 mg/Nm3(ii) a The concentration of HF in the defluorinated tail gas<0.001mg/Nm3(ii) a The moving bed is a counter-flow moving bed, alumina is quantitatively added from the top of the moving bed through a star-shaped feeder at a constant speed, gas enters from the bottom of the moving bed and is fully contacted with the moving bed, internal components in various shapes are arranged in the moving bed, the pressure drop of a bed layer is reduced, and a bell mouth discharging device is designed at the bottom to realize continuous discharging of the alumina;
(2) simultaneously spraying the defluorinated tail gas and ozone into a desulfurization reactor filled with zinc oxide slurry, wherein the zinc oxide slurry consists of water and zinc oxide, and the zinc oxide accounts for 10-20% of the total weight of the water under the initial condition; under the action of ozone and stirring condition, removing SO from tail gas2Reacting with zinc oxide to generate zinc sulfate, and performing desulfurization reaction on the zinc sulfate to form a zinc sulfate solution in water; the residual gas after the desulfurization reaction forms desulfurization tail gas to be discharged; SO in desulfurized tail gas2Concentration of (2)<20mg/Nm3(ii) a When the concentration of the zinc sulfate solution in the reaction tank reaches 150-300 g/L, discharging 1/3-1/4 of the whole zinc sulfate solution in the reactor; the mass flow ratio of the ozone to the defluorinated tail gas is 1: 3; the desulfurization reactor comprises a closed shell, and a stirring paddle and a filtering device which are arranged in the closed shell, wherein the stirring paddle is formed by combining an upper SSB-D stirring paddle and a lower intermix stirring paddle which are coaxial; the top of the shell is provided with a feed inlet and an air outlet, and the bottom of the shell is provided with an ozone inlet and a defluorination tail gas inlet; wherein the filter device is fixed on the side wall of the shell; the filtering device consists of a filter screen and a filter shell, the filter shell is fixed with the shell, the filter screen and a part of the shell enclose a filtering cavity, and the side wall of the shell is provided with a liquid discharge port for communicating the filtering cavity with the outside of the shell; the ozone inlet and the defluorinated tail gas inlet are respectively communicated with the ozone cavity and the tail gas cavity, and gas distributors are respectively arranged above the ozone cavity and the tail gas cavity; the use method of the desulfurization reactor comprises the following steps: blowing defluorinated tail gas and ozone at the bottom of the desulfurizing reactor, adding zinc oxide slurry from the upper feeding port, suspending the zinc oxide slurry by stirring paddles, breaking gas bubbles, micronizing the bubbles, and fully mixing gas, liquid and solid phasesMixing uniformly; quantitatively discharging zinc sulfate solution from the desulfurization reactor through a liquid outlet, intercepting unreacted zinc oxide in the desulfurization reactor by a filter screen, discharging the reacted desulfurization tail gas from the top of the desulfurization reactor, and performing mineralization and CO capture2A system;
(3) heating the discharged zinc sulfate solution, evaporating and concentrating, cooling to 25 +/-1 ℃ under the condition of water bath when crystals are separated out, preserving heat for 10-60 min, filtering to obtain a crystalline solid phase and a filtrate, and drying the obtained crystalline solid phase at 40-50 ℃ to remove non-crystalline water to obtain zinc sulfate heptahydrate;
(4) introducing a calcium ion-containing solution into a water inlet of the Venturi jet reactor, wherein the calcium ion concentration of the calcium ion-containing solution is 1.0-2.0 g/L; simultaneously introducing the desulfurization tail gas into an air inlet of the Venturi jet reactor, mixing the desulfurization tail gas with a calcium ion-containing solution for mineralization reaction, and trapping CO in the desulfurization tail gas2(ii) a The injection pressure of the calcium ion-containing solution is 0.5-2.0 MPa, and the injection pressure of the desulfurization tail gas is 0.2-1.2 MPa; obtaining reaction ore pulp containing calcium carbonate solid particles at a water outlet of the Venturi jet reactor, and discharging decarbonized tail gas from a gas outlet; CO in decarbonization tail gas2The concentration of (A) is 350-600 mg/Nm3。
2. The method for deeply purifying the tail gas discharged organically in the aluminum electrolysis production process according to claim 1, wherein the reaction ore pulp is dried and dehydrated to obtain calcium carbonate, the purity is more than or equal to 98.0 percent, and the whiteness is more than or equal to 85.0 percent.
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3911080A (en) * | 1971-09-10 | 1975-10-07 | Wright H Dudley | Air pollution control |
| CN101348924A (en) * | 2008-08-27 | 2009-01-21 | 商丘市丰源铝电有限责任公司 | Dry and wet methods combined aluminum electrolysis flue gas deep treatment process |
| CN102755826A (en) * | 2012-07-06 | 2012-10-31 | 江苏恒丰伟业科技工程有限公司 | Tail gas desulfuration adopting zinc oxide method in smelting industry |
| CN103446867A (en) * | 2013-08-28 | 2013-12-18 | 东北大学 | Method for preparing calcium carbonate and recycling CO by collecting and mineralizing CO2 in aluminum electrolysis flue gas |
| CN104911631A (en) * | 2015-06-18 | 2015-09-16 | 中国科学院过程工程研究所 | Novel method for efficiently purifying aluminum electrolysis fluorine-containing flue gas by using porous alumina |
| CN105836778A (en) * | 2016-03-24 | 2016-08-10 | 东北大学 | Method of producing carbonates and recycling energy by cyclically capturing and mineralizing CO2 |
| CN105879647A (en) * | 2016-01-13 | 2016-08-24 | 韦建初 | Waste-gypsum-residue-free desulfuration system and process thereof |
| CN107008141A (en) * | 2017-06-12 | 2017-08-04 | 北京中海威环保科技有限公司 | Desulfurization defluorinate device is devoked suitable for the dry method dust of aluminum i ndustry |
| CN107161957A (en) * | 2017-05-23 | 2017-09-15 | 西北矿冶研究院 | Method for preparing liquid sulfur dioxide by using acid-making tail gas |
-
2017
- 2017-11-27 CN CN201711202915.0A patent/CN107803108B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3911080A (en) * | 1971-09-10 | 1975-10-07 | Wright H Dudley | Air pollution control |
| CN101348924A (en) * | 2008-08-27 | 2009-01-21 | 商丘市丰源铝电有限责任公司 | Dry and wet methods combined aluminum electrolysis flue gas deep treatment process |
| CN102755826A (en) * | 2012-07-06 | 2012-10-31 | 江苏恒丰伟业科技工程有限公司 | Tail gas desulfuration adopting zinc oxide method in smelting industry |
| CN103446867A (en) * | 2013-08-28 | 2013-12-18 | 东北大学 | Method for preparing calcium carbonate and recycling CO by collecting and mineralizing CO2 in aluminum electrolysis flue gas |
| CN104911631A (en) * | 2015-06-18 | 2015-09-16 | 中国科学院过程工程研究所 | Novel method for efficiently purifying aluminum electrolysis fluorine-containing flue gas by using porous alumina |
| CN105879647A (en) * | 2016-01-13 | 2016-08-24 | 韦建初 | Waste-gypsum-residue-free desulfuration system and process thereof |
| CN105836778A (en) * | 2016-03-24 | 2016-08-10 | 东北大学 | Method of producing carbonates and recycling energy by cyclically capturing and mineralizing CO2 |
| CN107161957A (en) * | 2017-05-23 | 2017-09-15 | 西北矿冶研究院 | Method for preparing liquid sulfur dioxide by using acid-making tail gas |
| CN107008141A (en) * | 2017-06-12 | 2017-08-04 | 北京中海威环保科技有限公司 | Desulfurization defluorinate device is devoked suitable for the dry method dust of aluminum i ndustry |
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