Treatment method of non-ferrous metal flue gas
By combining pretreatment, semi-dry desulfurization, wet electrostatic precipitator and modified activated carbon adsorption, the problems of high cost and low efficiency in the treatment of non-ferrous metal flue gas have been solved, achieving efficient removal of heavy metal particles and gaseous pollutants, and reducing equipment investment and operating costs.
Patent Information
- Application Number
- CN202511469205.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-15
- Publication Date
- 2025-12-02
AI Technical Summary
Existing methods for treating non-ferrous metal flue gas suffer from high operating costs, unstable removal of gaseous pollutants, and low treatment efficiency. In particular, it is difficult to remove heavy metal particles and gaseous pollutants simultaneously.
A combined process of pretreatment, semi-dry desulfurization, wet electrostatic precipitator and heavy metal adsorption is adopted. Modified activated carbon loaded with sulfides is used for deep treatment. Heavy metal particles and gaseous pollutants are removed by cyclone dust removal, injection of quicklime slurry, wet electrostatic precipitator and modified activated carbon adsorption respectively.
It achieves efficient removal of heavy metal particles, SO2 and heavy metal vapors, with SO2 removal efficiency of 98% and mercury vapor and heavy metal particles removal efficiency of 98%, reducing equipment investment and operating costs and significantly improving the adsorption performance of gaseous pollutants.
Abstract
Description
Technical Field
[0001] This invention relates to the field of industrial waste gas treatment technology, and in particular to a method for treating non-ferrous metal fumes. Background Technology
[0002] Non-ferrous metal smelting processes generate large amounts of flue gas containing heavy metals (such as lead, cadmium, and mercury) and sulfur dioxide (SO2). Direct emission of this flue gas poses serious threats to the environment and human health. Common flue gas treatment methods currently include wet scrubbing, electrostatic precipitators, and bag filters. However, these traditional methods struggle to simultaneously remove both heavy metal particles and gaseous pollutants (SO2, heavy metal vapors), and suffer from low treatment efficiency, high equipment investment, and high operating costs. Particularly for gaseous pollutants, the adsorption materials used in existing treatment methods (such as activated carbon) have limitations due to their inactive surface chemistry, poor pore structure adaptability, poor adsorption selectivity, low capacity, and susceptibility to poisoning and deactivation by other components in the flue gas. This results in unstable and inefficient removal of gaseous pollutants.
[0003] Therefore, it is of great significance to develop an economical, environmentally friendly method for treating non-ferrous metal fumes that can simultaneously and efficiently remove heavy metal particles and gaseous pollutants. Summary of the Invention
[0004] In view of this, the present invention provides a method for treating non-ferrous metal fumes, in order to solve the problems of high operating costs, unstable removal effect on gaseous pollutants, and low treatment efficiency of existing non-ferrous metal fumes treatment methods.
[0005] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides a method for treating non-ferrous metal fumes, comprising the following steps: 1) Pretreatment: The non-ferrous metal flue gas is subjected to cyclone dust removal to obtain preliminarily purified flue gas; 2) Semi-dry desulfurization: The quicklime slurry is atomized and sprayed into the pre-purified flue gas for semi-dry desulfurization to obtain desulfurized flue gas; 3) Wet electrostatic precipitator: The desulfurization flue gas is treated with a wet electrostatic precipitator to obtain wet purified flue gas; 4) Heavy metal adsorption: Wet purification flue gas is mixed with modified activated carbon for heavy metal adsorption treatment to obtain purified flue gas, which is then demisted before being discharged. The modified activated carbon is activated carbon loaded with sulfides; the sulfides include sodium sulfide and / or potassium sulfide.
[0006] Preferably, the method for preparing the modified activated carbon includes the following steps: S1: Immerse activated carbon in an oxidant solution for pretreatment to obtain oxidized activated carbon; S2: Immerse the oxidized activated carbon in an aqueous solution of sulfide to perform modification treatment and obtain modified activated carbon.
[0007] Preferably, the activated carbon in step S1 has a particle size of 20-40 mesh; the oxidant solution includes one or more of nitric acid, sulfuric acid and hydrogen peroxide; the mass concentration of the nitric acid is 50-60%, the mass concentration of the sulfuric acid is 90-95%, and the mass concentration of the hydrogen peroxide is 30-35%.
[0008] Preferably, the pretreatment temperature in step S1 is 50~80℃ and the time is 6~8 h.
[0009] Preferably, the sulfide in the aqueous solution of the sulfide in step S2 includes sodium sulfide and / or potassium sulfide; the mass concentration of the sulfide in the aqueous solution of the sulfide is 15-20%.
[0010] Preferably, the temperature of the modification treatment in step S2 is 40~60℃ and the time is 4~8 h.
[0011] Preferably, the temperature of the non-ferrous metal flue gas in step 1) is 200~400℃, and the inlet wind speed of the cyclone dust collector is 16~20 m / s.
[0012] Preferably, the mass concentration of the quicklime slurry in step 2) is 20-30%; the molar ratio of S in the preliminarily purified flue gas to Ca in the quicklime slurry is 1.2-1.8:1; and the temperature of the semi-dry desulfurization is 110-130℃, and the time is 8-15 s.
[0013] Preferably, the temperature of the desulfurized flue gas in step 3) is 20~40℃; the voltage of the wet electrostatic precipitator is 40~70 kV and the time is 5~20 s.
[0014] Preferably, the volume-to-mass ratio of the wet-process purified flue gas to the modified activated carbon in step 4) is 1 Nm³. 3 The concentration of heavy metals is 100~120 mg; the temperature for heavy metal adsorption treatment is 20~40℃ and the time is 1~30 s; the demisting is performed using a wet electrostatic precipitator; the voltage of the wet electrostatic precipitator is 30~80 kV.
[0015] As can be seen from the above technical solution, compared with the prior art, the beneficial effects of the present invention are as follows: This invention utilizes pretreatment of non-ferrous metal flue gas, semi-dry desulfurization, wet electrostatic precipitator, and heavy metal adsorption to simultaneously remove heavy metal particles, SO2, and heavy metal vapors. The removal efficiency reaches 98% for SO2, 98% for mercury vapor, and 99% for lead chloride and cadmium oxide particles, achieving synergistic treatment of multiple pollutants. Specifically, this invention employs sulfide-loaded activated carbon for deep treatment of the flue gas, significantly enhancing the removal of gaseous pollutants. This sulfide-loaded activated carbon is obtained through a two-step process: oxidant pretreatment and sulfide modification. The oxidant introduces numerous oxygen-containing functional groups, such as carboxyl (-COOH), hydroxyl (-OH), and carbonyl (C=O), onto the activated carbon surface. These functional groups can adsorb Pb from the flue gas. 2+ Cd 2+ The method effectively removes heavy metal ions and synergistically enhances the effect of subsequent sulfide modification. The sulfides used in the modification process are water-soluble ionic compounds. After pretreatment with an oxidant, the surface of the activated carbon changes from hydrophobic to hydrophilic, making it easier for the sulfide aqueous solution to fully wet and penetrate into its internal pores. This allows for a more uniform and abundant loading of sulfides, thereby improving the adsorption performance for gaseous pollutants and solving the problems of unstable and inefficient removal of gaseous pollutants by traditional adsorption materials. Furthermore, the non-ferrous metal flue gas treatment method of this invention, through a combination of dry and wet treatment, not only improves the removal efficiency of heavy metal particles, SO2, and heavy metal vapors but also reduces equipment investment and operating costs, resulting in significant economic benefits. Detailed Implementation
[0016] This invention provides a method for treating non-ferrous metal fumes, comprising the following steps: 1) Pretreatment: The non-ferrous metal flue gas is subjected to cyclone dust removal to obtain preliminarily purified flue gas; 2) Semi-dry desulfurization: The quicklime slurry is atomized and sprayed into the pre-purified flue gas for semi-dry desulfurization to obtain desulfurized flue gas; 3) Wet electrostatic precipitator: The desulfurization flue gas is treated with a wet electrostatic precipitator to obtain wet purified flue gas; 4) Heavy metal adsorption: Wet purification flue gas is mixed with modified activated carbon for heavy metal adsorption treatment to obtain purified flue gas, which is then demisted before being discharged. The modified activated carbon is activated carbon loaded with sulfides; the sulfides include sodium sulfide and / or potassium sulfide.
[0017] In this invention, the method for preparing the modified activated carbon includes the following steps: S1: Immerse activated carbon in an oxidant solution for pretreatment to obtain oxidized activated carbon; S2: Immerse the oxidized activated carbon in an aqueous solution of sulfide to perform modification treatment and obtain modified activated carbon.
[0018] In this invention, the activated carbon in step S1 has a particle size of 20-40 mesh, preferably 22-38 mesh, more preferably 25-35 mesh, and even more preferably 30 mesh; the oxidant solution includes one or more of nitric acid, sulfuric acid, and hydrogen peroxide; the mass concentration of the nitric acid is 50-60%, preferably 52-58%, more preferably 53-55%; the mass concentration of the sulfuric acid is 90-95%, preferably 91-94%, more preferably 92-93%; and the mass concentration of the hydrogen peroxide is 30-35%, preferably 31-34%, more preferably 32-33%.
[0019] In this invention, the temperature of the pretreatment in step S1 is 50~80℃, preferably 55~75℃, more preferably 60~72℃, and even more preferably 65~70℃; the time of the pretreatment is 6~8 h, preferably 6.2~7.8 h, more preferably 6.5~7.5 h, and even more preferably 6.8~7.0 h.
[0020] In this invention, the pretreatment in step S1 preferably includes a drying operation to remove moisture; the drying temperature is preferably 105~115℃, more preferably 108~113℃, and even more preferably 110~112℃; the drying time is preferably 6~12 h, more preferably 7~10 h, and even more preferably 8~9 h.
[0021] In this invention, the sulfide in the aqueous solution of the sulfide in step S2 includes sodium sulfide and / or potassium sulfide; the mass concentration of the sulfide in the aqueous solution of the sulfide is 15-20%, preferably 16-19%, and more preferably 17-18%.
[0022] In this invention, the temperature of the modification treatment in step S2 is 40~60℃, preferably 42~58℃, more preferably 45~55℃, and even more preferably 48~50℃; the time of the modification treatment is 4~8 h, preferably 4.5~7.5 h, more preferably 5~7 h, and even more preferably 5.5~6 h.
[0023] In this invention, the modification treatment in step S2 preferably includes a drying operation; the drying atmosphere is preferably an inert atmosphere; the inert atmosphere is preferably nitrogen and / or argon; the drying temperature is preferably 105~120℃, more preferably 108~115℃, and more preferably 110~112℃; the drying time is preferably 6~12 h, more preferably 7~11 h, and more preferably 8~10 h.
[0024] In this invention, the temperature of the non-ferrous metal flue gas in step 1) is 200~400℃, preferably 220~380℃, more preferably 250~350℃, and even more preferably 280~300℃; the inlet wind speed of the cyclone dust collector is 16~20 m / s, preferably 16.5~19 m / s, more preferably 17~18.5 m / s, and even more preferably 17.5~18 m / s.
[0025] In this invention, the mass concentration of the quicklime slurry in step 2) is 20-30%, preferably 22-28%, more preferably 24-26%, and even more preferably 25%; the molar ratio of S in the pre-purified flue gas to Ca in the quicklime slurry is 1.2-1.8:1, preferably 1.3-1.7:1, more preferably 1.4-1.6:1, and even more preferably 1.5:1; the temperature of the semi-dry desulfurization is 110-130℃, preferably 112-128℃, more preferably 115-125℃, and even more preferably 120-122℃; the time of the semi-dry desulfurization is 8-15 s, preferably 9-14 s, more preferably 10-13 s, and even more preferably 11-12 s; after the quicklime slurry in step 2) is atomized and sprayed into the pre-purified flue gas, it reacts with SO2 in the pre-purified flue gas to generate CaSO3 and CaSO4, thereby improving the desulfurization efficiency.
[0026] In this invention, the temperature of the desulfurized flue gas in step 3) is 20~40℃, preferably 22~38℃, more preferably 25~35℃, and even more preferably 28~30℃; the voltage of the wet electrostatic precipitator is 40~70 kV, preferably 43~68 kV, more preferably 45~65 kV, and even more preferably 50~60 kV; the time of the wet electrostatic precipitator is 5~20 s, preferably 8~18 s, more preferably 10~16 s, and even more preferably 12~15 s.
[0027] In this invention, the volume-to-mass ratio of the wet-process purified flue gas to the modified activated carbon in step 4) is 1 Nm. 3 100~120 mg, preferably 1 Nm 3 105~118 mg, more preferably 1 Nm 3 108~115 mg, more preferably 1 Nm 3The concentration of heavy metals is 110~112 mg; the temperature for heavy metal adsorption treatment is 20~40℃, preferably 22~38℃, more preferably 25~35℃, and even more preferably 28~30℃; the time for heavy metal adsorption treatment is 1~30 s, preferably 2~25 s, more preferably 5~20 s, and even more preferably 8~15 s; the demisting is performed using a wet electrostatic precipitator; the voltage of the wet electrostatic precipitator is 30~80 kV, preferably 35~75 kV, more preferably 40~70 kV, and even more preferably 50~60 kV.
[0028] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.
[0029] Example 1
[0030] 1) Pretreatment: Simulated non-ferrous metal flue gas at 300℃ (SO2 volume concentration of 1200 ppm, mercury vapor volume concentration of 1.5 mg / Nm³) was used. 3 The volume concentration of lead chloride particles was 50 mg / Nm³. 3 The volume concentration of cadmium oxide particles was 20 mg / Nm³. 3 The flue gas is introduced into a cyclone dust collector, and the inlet velocity is controlled at 16 m / s to obtain preliminary purified flue gas. 2) Semi-dry desulfurization: The slaked lime slurry (mass concentration of 20%) is atomized and sprayed into the pre-purified flue gas (the molar ratio of S in the pre-purified flue gas to Ca in the slaked lime slurry is 1.2:1). Semi-dry desulfurization is carried out at 110℃ for 15s to obtain desulfurized flue gas. 3) Wet electrostatic precipitator: The desulfurized flue gas at 20℃ is passed into a wet electrostatic precipitator and treated for 20 seconds under a high-voltage electric field of 40 kV to obtain wet purified flue gas; 4) Heavy metal adsorption: First, 40-mesh activated carbon is immersed in a nitric acid solution (mass concentration of 55%) and stirred at 50℃ for 6 h, then dried at 105℃ for 12 h to obtain oxidized activated carbon; the oxidized activated carbon is then immersed in an aqueous solution of sodium sulfide (mass concentration of 15%) and modified at 40℃ for 8 h, then dried at 105℃ for 12 h under a nitrogen protective atmosphere to obtain modified activated carbon; then, the wet-process purified flue gas is passed into a fixed-bed adsorption tower, which is filled with the above-mentioned modified activated carbon, and the volume-to-mass ratio of wet-process purified flue gas to modified activated carbon is controlled at 1 Nm³. 3 100 mg of the sample was reacted at 20°C for 30 seconds to obtain purified flue gas. The purified flue gas was then passed into a wet electrostatic precipitator to remove residual mist droplets at a voltage of 30 kV, resulting in the final purified flue gas, which was then discharged by an induced draft fan.
[0031] The SO2 content in the exhaust gas from the induced draft fan was detected using an infrared flue gas analyzer, the Hg content using a cold atomic absorption spectrometer, and the content of lead chloride particles and cadmium oxide particles using an inductively coupled plasma mass spectrometer. The results showed that the SO2 removal efficiency reached 97%, the mercury vapor removal efficiency reached 95%, and the lead chloride and cadmium oxide particle removal efficiency reached 97%.
[0032] Example 2
[0033] 1) Pretreatment: Simulated non-ferrous metal flue gas at 400℃ (SO2 volume concentration of 1200 ppm, mercury vapor volume concentration of 1.5 mg / Nm³) was used. 3 The volume concentration of lead chloride particles was 50 mg / Nm³. 3 The volume concentration of cadmium oxide particles was 20 mg / Nm³. 3 The flue gas is introduced into a cyclone dust collector, and the inlet velocity is controlled at 18 m / s to obtain preliminary purified flue gas. 2) Semi-dry desulfurization: The slaked lime slurry (mass concentration of 25%) is atomized and sprayed into the pre-purified flue gas (the molar ratio of S in the pre-purified flue gas to Ca in the slaked lime slurry is 1.5:1). Semi-dry desulfurization is carried out at 120℃ for 10s to obtain desulfurized flue gas. 3) Wet electrostatic precipitator: The desulfurized flue gas at 30℃ is passed into a wet electrostatic precipitator and treated for 15 seconds under a high-voltage electric field of 55 kV to obtain wet purified flue gas; 4) Heavy metal adsorption: First, 30-mesh activated carbon is immersed in a sulfuric acid solution (mass concentration of 92%) and stirred at 65℃ for 7.5 h, then dried at 110℃ for 10 h to obtain oxidized activated carbon; the oxidized activated carbon is then immersed in an aqueous solution of potassium sulfide (sodium sulfide mass concentration of 18%) and modified at 50℃ for 6 h, then dried at 115℃ for 10 h under a nitrogen protective atmosphere to obtain modified activated carbon; then, the wet-process purified flue gas is passed into a fixed-bed adsorption tower, which is filled with the above-mentioned modified activated carbon, and the volume-to-mass ratio of wet-process purified flue gas to modified activated carbon is controlled at 1 Nm³. 3 110 mg was reacted at 30°C for 20 seconds to obtain purified flue gas. Finally, the purified flue gas was passed into a wet electrostatic precipitator to remove residual mist droplets at a voltage of 55 kV, and the final purified flue gas was discharged by an induced draft fan.
[0034] SO2, mercury vapor, lead chloride particles, and cadmium oxide particles in the exhaust gas of the induced draft fan were detected using the same detection method as in Example 1. The results showed that the removal efficiency of SO2 reached 98%, the removal efficiency of mercury vapor reached 96%, and the removal efficiency of lead chloride particles and cadmium oxide particles reached 98%.
[0035] Example 3
[0036] 1) Pretreatment: Simulated non-ferrous metal flue gas at 400℃ (SO2 volume concentration of 1200 ppm, mercury vapor volume concentration of 1.5 mg / Nm³) was used. 3 The volume concentration of lead chloride particles was 50 mg / Nm³. 3 The volume concentration of cadmium oxide particles was 20 mg / Nm³. 3 The flue gas is introduced into a cyclone dust collector, and the inlet velocity is controlled at 20 m / s to obtain preliminary purified flue gas. 2) Semi-dry desulfurization: The slaked lime slurry (mass concentration of 30%) is atomized and sprayed into the pre-purified flue gas (the molar ratio of S in the pre-purified flue gas to Ca in the slaked lime slurry is 1.8:1). Semi-dry desulfurization is carried out at 130℃ for 8 s to obtain desulfurized flue gas. 3) Wet electrostatic precipitator: The desulfurized flue gas at 40℃ is passed into a wet electrostatic precipitator and treated for 5 seconds under a high voltage electric field of 70 kV to obtain wet purified flue gas; 4) Heavy metal adsorption: First, 20-mesh activated carbon is immersed in a nitric acid solution (60% mass concentration) and stirred at 80℃ for 6 h, then dried at 115℃ for 6 h to obtain oxidized activated carbon; the oxidized activated carbon is then immersed in an aqueous solution of sodium sulfide (20% mass concentration) and modified at 60℃ for 4 h, then dried at 120℃ for 6 h under a nitrogen protective atmosphere to obtain modified activated carbon; then, the wet-process purified flue gas is passed into a fixed-bed adsorption tower, which is filled with the above-mentioned modified activated carbon, and the volume-to-mass ratio of wet-process purified flue gas to modified activated carbon is controlled at 1 Nm³. 3 120 mg was reacted at 40°C for 5 seconds to obtain purified flue gas. Finally, the purified flue gas was passed into a wet electrostatic precipitator to remove residual mist droplets at a voltage of 80 kV, and the final purified flue gas was discharged by an induced draft fan.
[0037] SO2, mercury vapor, lead chloride particles, and cadmium oxide particles in the exhaust gas of the induced draft fan were detected using the same detection method as in Example 1. The results showed that the removal efficiency of SO2 reached 98%, the removal efficiency of mercury vapor reached 98%, and the removal efficiency of lead chloride particles and cadmium oxide particles reached 99%.
[0038] Comparative Example 1
[0039] The only difference between Comparative Example 1 and Example 3 is that unmodified activated carbon was used in step 4).
[0040] SO2, mercury vapor, lead chloride particles, and cadmium oxide particles in the exhaust gas of the induced draft fan were detected using the same detection method as in Example 1. The results showed that the removal efficiency of SO2 reached 70%, the removal efficiency of mercury vapor reached 68%, and the removal efficiency of lead chloride particles and cadmium oxide particles reached 75%.
[0041] Comparative Example 2
[0042] The only difference between Comparative Example 2 and Example 3 is that the modified activated carbon in step 4) is prepared by immersing 20-mesh activated carbon in an aqueous solution of sodium sulfide (sodium sulfide mass concentration of 20%), modifying it at 60°C for 4 h, and then drying it at 120°C for 6 h under a nitrogen protective atmosphere to obtain modified activated carbon.
[0043] SO2, mercury vapor, lead chloride particles, and cadmium oxide particles in the exhaust gas of the induced draft fan were detected using the same detection method as in Example 1. The results showed that the removal efficiency of SO2 reached 78%, the removal efficiency of mercury vapor reached 72%, and the removal efficiency of lead chloride particles and cadmium oxide particles reached 80%.
[0044] Comparative Example 3
[0045] The only difference between Comparative Example 3 and Example 3 is that the modified activated carbon in step 4) is prepared by immersing 20-mesh activated carbon in a nitric acid solution (mass concentration of 60%), stirring and reacting at 80°C for 6 h, and then drying at 115°C for 6 h to obtain modified activated carbon.
[0046] SO2, mercury vapor, lead chloride particles, and cadmium oxide particles in the exhaust gas of the induced draft fan were detected using the same detection method as in Example 1. The results showed that the removal efficiency of SO2 reached 75%, the removal efficiency of mercury vapor reached 68%, and the removal efficiency of lead chloride particles and cadmium oxide particles reached 76%.
[0047] As can be seen from Examples 1-3 above, the treatment method of the present invention can achieve a SO2 removal efficiency of 98%, a mercury vapor removal efficiency of 98%, and a lead chloride particle and cadmium oxide particle removal efficiency of 99% when treating non-ferrous metal flue gas, greatly improving the removal efficiency of heavy metal particles, SO2, and heavy metal vapors. Furthermore, the activated carbon used in Comparative Examples 1 and 3 was not loaded with sulfides, resulting in poor adsorption selectivity and easy deactivation by other components in the flue gas, leading to unstable and low efficiency in the removal of gaseous pollutants. Although the activated carbon used in Comparative Example 2 was loaded with sulfides, it was not pretreated with an oxidant, resulting in uneven and low sulfide loading, leading to poor removal of gaseous pollutants. In contrast, the modified activated carbon used in Example 3 of the present invention was uniformly loaded with a large amount of sulfides, greatly improving the removal efficiency of gaseous pollutants and solving the problem of unstable removal efficiency and low treatment efficiency of existing treatment methods for gaseous pollutants.
[0048] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A method for treating non-ferrous metal fumes, characterized in that, Includes the following steps: 1) Pretreatment: The non-ferrous metal flue gas is subjected to cyclone dust removal to obtain preliminarily purified flue gas; 2) Semi-dry desulfurization: The quicklime slurry is atomized and sprayed into the pre-purified flue gas for semi-dry desulfurization to obtain desulfurized flue gas; 3) Wet electrostatic precipitator: The desulfurization flue gas is treated with a wet electrostatic precipitator to obtain wet purified flue gas; 4) Heavy metal adsorption: Wet purification flue gas is mixed with modified activated carbon for heavy metal adsorption treatment to obtain purified flue gas, which is then demisted before being discharged. The modified activated carbon is sulfide-loaded activated carbon; The sulfides include sodium sulfide and / or potassium sulfide.
2. The method for treating non-ferrous metal fumes according to claim 1, characterized in that, The method for preparing the modified activated carbon includes the following steps: S1: Immerse activated carbon in an oxidant solution for pretreatment to obtain oxidized activated carbon; S2: Immerse the oxidized activated carbon in an aqueous solution of sulfide to perform modification treatment and obtain modified activated carbon.
3. The method for treating non-ferrous metal fumes according to claim 2, characterized in that, The activated carbon in step S1 has a particle size of 20-40 mesh; the oxidant solution includes one or more of nitric acid, sulfuric acid, and hydrogen peroxide. The mass concentration of the nitric acid is 50-60%, the mass concentration of the sulfuric acid is 90-95%, and the mass concentration of the hydrogen peroxide is 30-35%.
4. The method for treating non-ferrous metal fumes according to claim 3, characterized in that, The pretreatment temperature in step S1 is 50~80℃, and the time is 6~8 h.
5. The method for treating non-ferrous metal fumes according to claim 4, characterized in that, The sulfides in the aqueous solution of the sulfides mentioned in step S2 include sodium sulfide and / or potassium sulfide; The mass concentration of sulfide in the aqueous solution of the sulfide is 15-20%.
6. The method for treating non-ferrous metal fumes according to claim 5, characterized in that, The modification treatment in step S2 is carried out at a temperature of 40~60℃ for 4~8 hours.
7. A method for treating non-ferrous metal fumes according to any one of claims 1 to 6, characterized in that, The temperature of the non-ferrous metal flue gas in step 1) is 200~400℃, and the inlet wind speed of the cyclone dust collector is 16~20 m / s.
8. The method for treating non-ferrous metal fumes according to claim 7, characterized in that, The mass concentration of the slaked lime slurry mentioned in step 2) is 20-30%; The molar ratio of S in the preliminarily purified flue gas to Ca in the slaked lime slurry is 1.2~1.8:1; The semi-dry desulfurization process involves a temperature of 110~130℃ and a time of 8~15 s.
9. The method for treating non-ferrous metal fumes according to claim 8, characterized in that, The temperature of the desulfurized flue gas mentioned in step 3) is 20~40℃; The voltage of the wet electrostatic precipitator is 40~70 kV, and the time is 5~20 s.
10. The method for treating non-ferrous metal fumes according to claim 9, characterized in that, In step 4), the volume-to-mass ratio of the wet-process purified flue gas to the modified activated carbon is 1 Nm³. 3 100~120 mg; The heavy metal adsorption treatment is performed at a temperature of 20~40℃ for a time of 1~30 s. The demisting process employs a wet electrostatic precipitator; the voltage of the wet electrostatic precipitator is 30~80 kV.