A system for treating exhaust gas from antimony ingot production

Abstract

The application relates to the technical field of waste gas treatment, in particular to an antimony ingot production waste gas treatment system which comprises a cooling unit, a dust removal unit and an adsorption unit; the adsorption unit comprises a first adsorption unit and a second adsorption unit; the first adsorption unit reduces the SO2 content in waste gas through a sodium alkali method to obtain low SO2 concentration waste gas; the second adsorption unit processes the low SO2 concentration waste gas through an ultracrosslinked porous ionic polymer to obtain purified waste gas; after being processed by the system, the SO2 content in the waste gas is less than or equal to 50 mg / m 3 , which meets the waste gas emission standard.

Description

Technical Field

[0001] This invention relates to the field of waste gas treatment technology, specifically to a waste gas treatment system for antimony ingot production. Background Technology

[0002] Antimony smelting technology is divided into pyrometallurgical and hydrometallurgical methods. Currently, pyrometallurgical technology is dominant. The representative process of pyrometallurgical antimony smelting is the "blast furnace volatilization smelting - reverberatory furnace reduction" process.

[0003] The blast furnace volatilization smelting process has advantages such as strong raw material adaptability, high metal recovery rate, large production capacity, and easy mechanical operation. However, this process has disadvantages such as large waste gas generation and high SO2 concentration in the flue gas. Summary of the Invention

[0004] Purpose of the invention: To address the above-mentioned technical problems, this invention proposes a waste gas treatment system for antimony ingot production.

[0005] The technical solution adopted is as follows:

[0006] A waste gas treatment system for antimony ingot production includes a cooling unit, a dust removal unit, and an adsorption unit;

[0007] The adsorption unit includes a first adsorption unit and a second adsorption unit;

[0008] The first adsorption unit reduces the SO2 content in the waste gas using the sodium alkali method, resulting in waste gas with low SO2 concentration.

[0009] The second adsorption unit treats low SO2 concentration waste gas with a hypercrosslinked porous ionomer to obtain purified waste gas.

[0010] Furthermore, the hypercrosslinked porous ionic polymer is prepared from 1-(4-vinylbenzyl)-1H-imidazolium as a raw material.

[0011] Furthermore, the preparation method of the hypercrosslinked porous ionomer is as follows:

[0012] The super-crosslinked porous ionic polymer is obtained by self-polymerization of 1-(4-vinylbenzyl)-1H-imidazolium, followed by quaternization with a haloalkylamine and finally anion exchange.

[0013] Furthermore, the preparation method of the hypercrosslinked porous ionomer is as follows:

[0014] Under a protective gas atmosphere, 1-(4-vinylbenzyl)-1H-imidazolium and a free radical catalyst are added to the first solvent, mixed and stirred until homogeneous, heated and reacted for 8-12 hours, then restored to room temperature and filtered. The resulting solid is washed and dried, added to the second solvent, and then a haloalkylamine is added. The mixture is heated and reacted for 24-48 hours, concentrated under reduced pressure, and the resulting solid is washed and dried with the third solvent. The mixture is added to the fourth solvent, and then sodium proline is added. The mixture is reacted at room temperature for 48-60 hours, filtered, and the filtrate is collected and concentrated under reduced pressure.

[0015] Furthermore, the first solvent, the second solvent, the third solvent, and the fourth solvent are any one or more combinations of petroleum ether, acetone, methanol, ethanol, dichloromethane, ethyl acetate, benzene, toluene, DMF, DMSO, or water.

[0016] Furthermore, the haloalkylamine is a chlorine, bromine, or iodine-substituted alkylamine, and the alkylamine has ≥4 carbon atoms.

[0017] Furthermore, the haloalkylamine is chlorobutylamine or chloropentamine.

[0018] Furthermore, the first adsorption unit includes a packed tower and packing material filled in the packed tower. After being cooled by the cooling unit, the waste gas enters the packed tower from the air inlet at the bottom of the packed tower and comes into contact with the absorbent liquid flowing in from the liquid inlet at the top of the packed tower.

[0019] Furthermore, the absorbent is a sodium hydroxide solution or a sodium carbonate solution.

[0020] Furthermore, the packing material is a rectangular saddle ring, a Raschig ring, or a Pall ring.

[0021] The beneficial effects of this invention are:

[0022] This invention provides a waste gas treatment system for antimony ingot production. By combining a first adsorption unit and a second adsorption unit, the SO2 content in the waste gas is reduced to meet emission standards. While the sodium alkali method is technically mature and the generated ash can be recycled as building materials after precipitation, it has become increasingly unsuitable due to stricter emission standards. In recent years, researchers have attempted to develop ionic porous organic polymers and, by controlling the polymer's framework structure and altering the types of equilibrium ions, regulate its structure and properties. This has led to its broad application prospects in proton conduction, heterogeneous catalysis, antibacterial applications, and wastewater treatment. The super-crosslinked porous ionic polymer prepared from 1-(4-vinylbenzyl)-1H-imidazolium in this invention exhibits high specific surface area, good water and thermal stability, and significantly enhanced SO2 adsorption by introducing polar functional groups (amine groups) and two basic adsorption sites (carboxylic acid anion and amine group) from the proline anion. After treatment, the SO2 content in the waste gas is ≤50 mg / m³.3 It meets the exhaust emission standards. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the antimony ingot production waste gas treatment system in Embodiment 1 of the present invention. The numbers in the diagram represent:

[0024] 1-Cooling unit, 2-Liquid storage tank, 3-Pall ring packing, 4-Nozzle, 5-First adsorption unit, 6-Second adsorption unit, 7-Hypercrosslinked porous ion polymer, 8-Dust removal unit.

[0025] Figure 2 This is a SEM image of the hypercrosslinked porous ionomer in Example 1. Detailed Implementation

[0026] Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer should be followed. Reagents or instruments whose manufacturers are not specified are all commercially available products. Techniques not mentioned in this invention refer to existing technologies.

[0027] Example 1:

[0028] refer to Figure 1 This embodiment provides an antimony ingot production waste gas treatment system, including a cooling unit (1), a dust removal unit (8), a first adsorption unit (5), and a second adsorption unit (6) connected by pipelines.

[0029] The cooling unit (1) is a spiral plate heat exchanger;

[0030] The dust removal unit (8) is a pulse bag filter;

[0031] The first adsorption unit (5) includes a packed tower and Pall ring packing (3) filled in the packed tower. After the exhaust gas is cooled by the cooling unit (1) and dusted by the dust removal unit (8), it enters the packed tower from the air inlet at the bottom of the packed tower. 1.5 mol / L sodium hydroxide solution is stored in the storage tank (2) as the absorbent. After being pumped by the water pump, it flows into the top of the packed tower through the pipe. After being sprayed by the nozzle (4), it passes through the Pall ring packing (3) from top to bottom and is absorbed by the exhaust gas from bottom to top. Finally, it is discharged from the bottom of the tower to the receiving tank (not shown in the figure). After the exhaust gas is treated once, it becomes low SO2 concentration exhaust gas. The low SO2 concentration exhaust gas enters the second adsorption unit (6) through the pipe. The second adsorption unit (6) adsorbs the low SO2 concentration exhaust gas through the hypercrosslinked porous ion polymer (7) to obtain purified exhaust gas.

[0032] The preparation method of the hypercrosslinked porous ionic polymer is as follows: ;

[0033] Add 200g of 1-(4-vinylbenzyl)-1H-imidazole and 10g of AIBN to 500mL of ethanol, mix and stir well, heat to 70℃ and react for 8-12h, then restore to room temperature and filter. Wash the obtained solid with ethanol and dry it. Add 184g of the solid to 650mL of DMSO, then add 128g of 4-chloro-1-butanamine, heat to 80℃ and react for 24-48h. Concentrate under reduced pressure to remove DMSO, wash the obtained solid with petroleum ether and dry it to obtain an intermediate. Add 200g of the intermediate to 1L of xylene, then add 80g of sodium proline, react at room temperature for 48-60h, filter, collect the filtrate, concentrate under reduced pressure and dry the obtained solid.

[0034] The composition of the antimony ingot production waste gas, excluding dust, was simulated. The main components of the simulated waste gas were SO2, N2, and O2, with an SO2 concentration of 8540 mg / m³. 3 The temperature was 625℃ and the total volumetric flow rate was 500 mL·min. -1 After being cooled by the cooling unit (1), the temperature dropped to 132℃. After being treated by the dust removal and first adsorption unit (5), the SO2 content in the exhaust gas dropped to 1652 mg / m³. 3 The temperature was 68℃, and after treatment by the second adsorption unit (6), the SO2 content in the waste gas was reduced to 31 mg / m³. 3 It fully meets the emission requirements of the "Emission Standard of Air Pollutants for Industrial Furnaces and Kilns" (DB411066-2020).

[0035] Example 2:

[0036] It is basically the same as Example 1, except that 4-chloro-1-butanamine is replaced with the same amount of 4-chloro-1-pentanamine.

[0037] The composition of the antimony ingot production waste gas, excluding dust, was simulated. The main components of the simulated waste gas were SO2, N2, and O2, with an SO2 concentration of 8540 mg / m³. 3 The temperature was 625℃ and the total volumetric flow rate was 500 mL·min. -1 After being cooled by the cooling unit (1), the temperature dropped to 127℃. After being treated by the dust removal and first adsorption unit (5), the SO2 content in the exhaust gas dropped to 1664 mg / m³. 3 The temperature was 62℃, and the SO2 content in the exhaust gas was reduced to 28 mg / m³ after treatment by the second adsorption unit (6). 3 It fully meets the emission requirements of the "Emission Standard of Air Pollutants for Industrial Furnaces and Kilns" (DB411066-2020).

[0038] Comparative Example 1:

[0039] The method is basically the same as in Example 1, except that an intermediate is used as an adsorbent to treat waste gas with low SO2 concentration.

[0040] The composition of the antimony ingot production waste gas, excluding dust, was simulated. The main components of the simulated waste gas were SO2, N2, and O2, with an SO2 concentration of 8540 mg / m³. 3 The temperature was 625℃ and the total volumetric flow rate was 500 mL·min. -1 After being cooled by the cooling unit (1), the temperature dropped to 135℃. After being treated by the dust removal and first adsorption unit (5), the SO2 content in the exhaust gas dropped to 1670mg / m³. 3 The temperature was 70℃, and the SO2 content in the waste gas was reduced to 207 mg / m³ after treatment by the second adsorption unit (6). 3 .

[0041] Comparative Example 2:

[0042] It is basically the same as Example 1, except that 1-chlorobutane is used instead of 4-chloro-1-butamine.

[0043] The composition of the antimony ingot production waste gas, excluding dust, was simulated. The main components of the simulated waste gas were SO2, N2, and O2, with an SO2 concentration of 8540 mg / m³. 3 The temperature was 625℃ and the total volumetric flow rate was 500 mL·min. -1 After being cooled by the cooling unit (1), the temperature dropped to 140℃. After being treated by the dust removal and first adsorption unit (5), the SO2 content in the exhaust gas dropped to 1637 mg / m³. 3 The temperature was 65℃, and after treatment by the second adsorption unit (6), the SO2 content in the waste gas was reduced to 116 mg / m³. 3 .

[0044] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A waste gas treatment system for antimony ingot production, characterized in that, Includes a cooling unit, a dust removal unit, and an adsorption unit; The adsorption unit includes a first adsorption unit and a second adsorption unit; the first adsorption unit reduces the SO2 content in the waste gas by sodium alkali method to obtain waste gas with low SO2 concentration. The second adsorption unit treats low SO2 concentration waste gas using a hypercrosslinked porous ionomer to obtain purified waste gas. The hypercrosslinked porous ionic polymer was prepared from 1-(4-vinylbenzyl)-1H-imidazol as a raw material; The preparation method of the hypercrosslinked porous ionomer is as follows: Under a protective gas atmosphere, 1-(4-vinylbenzyl)-1H-imidazolium and a free radical catalyst were added to the first solvent, mixed and stirred until homogeneous, and heated to react for 8-12 h. After restoring to room temperature, the mixture was filtered, and the resulting solid was washed and dried. It was then added to the second solvent, followed by the addition of a haloalkylamine, and heated to react for 24-48 h. The mixture was concentrated under reduced pressure, and the resulting solid was washed and dried with the third solvent. It was then added to the fourth solvent, followed by the addition of sodium proline. The mixture was reacted at room temperature for 48-60 h, filtered, and the filtrate was collected and concentrated under reduced pressure. The halogenated alkylamine is a chlorine, bromine, or iodine-substituted alkylamine, and the alkylamine has ≥4 carbon atoms.

2. The antimony ingot production waste gas treatment system as described in claim 1, characterized in that, The first solvent, the second solvent, the third solvent, and the fourth solvent are any one or more combinations of petroleum ether, acetone, methanol, ethanol, dichloromethane, ethyl acetate, benzene, toluene, DMF, DMSO, or water.

3. The antimony ingot production waste gas treatment system as described in claim 1, characterized in that, The haloalkylamine is chlorobutylamine or chloropentamine.

4. The antimony ingot production waste gas treatment system as described in claim 1, characterized in that, The first adsorption unit includes a packed tower and packing material filled in the packed tower. After being cooled by the cooling unit, the waste gas enters the packed tower from the air inlet at the bottom of the packed tower and comes into contact with the absorbent liquid flowing in from the liquid inlet at the top of the packed tower.

5. The antimony ingot production waste gas treatment system as described in claim 4, characterized in that, The absorbent is a sodium hydroxide solution or a sodium carbonate solution.

6. The antimony ingot production waste gas treatment system as described in claim 4, characterized in that, The packing material is a rectangular saddle ring, Raschig ring, or Pall ring.

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