CN115535971A - Method for preparing high-purity electronic grade sulfuric acid from waste sulfuric acid solution - Google Patents
Method for preparing high-purity electronic grade sulfuric acid from waste sulfuric acid solution Download PDFInfo
- Publication number
- CN115535971A CN115535971A CN202110724762.6A CN202110724762A CN115535971A CN 115535971 A CN115535971 A CN 115535971A CN 202110724762 A CN202110724762 A CN 202110724762A CN 115535971 A CN115535971 A CN 115535971A
- Authority
- CN
- China
- Prior art keywords
- sulfuric acid
- purity
- electronic
- concentration
- grade
- 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
Links
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 title claims abstract description 466
- 239000002699 waste material Substances 0.000 title claims abstract description 82
- 238000000034 method Methods 0.000 title claims abstract description 40
- AKEJUJNQAAGONA-UHFFFAOYSA-N sulfur trioxide Chemical compound O=S(=O)=O AKEJUJNQAAGONA-UHFFFAOYSA-N 0.000 claims abstract description 123
- 239000000945 filler Substances 0.000 claims abstract description 17
- 229920001343 polytetrafluoroethylene Polymers 0.000 claims abstract description 11
- 239000004810 polytetrafluoroethylene Substances 0.000 claims abstract description 11
- 229910021645 metal ion Inorganic materials 0.000 claims abstract description 10
- 239000003595 mist Substances 0.000 claims abstract description 6
- 239000002253 acid Substances 0.000 claims abstract description 5
- RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 claims description 87
- 239000007789 gas Substances 0.000 claims description 86
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims description 25
- 238000006243 chemical reaction Methods 0.000 claims description 16
- 238000005336 cracking Methods 0.000 claims description 14
- 230000001590 oxidative effect Effects 0.000 claims description 12
- -1 polytetrafluoroethylene Polymers 0.000 claims description 12
- 238000001704 evaporation Methods 0.000 claims description 10
- 230000008020 evaporation Effects 0.000 claims description 10
- 238000001816 cooling Methods 0.000 claims description 9
- 229920001577 copolymer Polymers 0.000 claims description 9
- 229920001774 Perfluoroether Polymers 0.000 claims description 8
- 238000000746 purification Methods 0.000 claims description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 8
- 239000003054 catalyst Substances 0.000 claims description 7
- 239000000463 material Substances 0.000 claims description 7
- 239000007800 oxidant agent Substances 0.000 claims description 7
- 238000012856 packing Methods 0.000 claims description 7
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 6
- GNTDGMZSJNCJKK-UHFFFAOYSA-N divanadium pentaoxide Chemical group O=[V](=O)O[V](=O)=O GNTDGMZSJNCJKK-UHFFFAOYSA-N 0.000 claims description 6
- 239000001301 oxygen Substances 0.000 claims description 6
- 229910052760 oxygen Inorganic materials 0.000 claims description 6
- 238000001914 filtration Methods 0.000 claims description 5
- LCPVQAHEFVXVKT-UHFFFAOYSA-N 2-(2,4-difluorophenoxy)pyridin-3-amine Chemical compound NC1=CC=CN=C1OC1=CC=C(F)C=C1F LCPVQAHEFVXVKT-UHFFFAOYSA-N 0.000 claims description 3
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 claims description 3
- 239000000428 dust Substances 0.000 claims description 3
- CHQMHPLRPQMAMX-UHFFFAOYSA-L sodium persulfate Substances [Na+].[Na+].[O-]S(=O)(=O)OOS([O-])(=O)=O CHQMHPLRPQMAMX-UHFFFAOYSA-L 0.000 claims description 3
- 229910021642 ultra pure water Inorganic materials 0.000 claims description 3
- 239000012498 ultrapure water Substances 0.000 claims description 3
- 239000011148 porous material Substances 0.000 claims description 2
- 239000004065 semiconductor Substances 0.000 abstract description 9
- 238000004519 manufacturing process Methods 0.000 abstract description 4
- 239000000243 solution Substances 0.000 description 76
- 238000004458 analytical method Methods 0.000 description 12
- HIFJUMGIHIZEPX-UHFFFAOYSA-N sulfuric acid;sulfur trioxide Chemical compound O=S(=O)=O.OS(O)(=O)=O HIFJUMGIHIZEPX-UHFFFAOYSA-N 0.000 description 10
- 238000002835 absorbance Methods 0.000 description 9
- 239000003153 chemical reaction reagent Substances 0.000 description 9
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 7
- 238000010521 absorption reaction Methods 0.000 description 7
- 229910052799 carbon Inorganic materials 0.000 description 7
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 6
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 6
- 239000000126 substance Substances 0.000 description 5
- 238000000870 ultraviolet spectroscopy Methods 0.000 description 5
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 4
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 4
- 238000001514 detection method Methods 0.000 description 4
- 229910052717 sulfur Inorganic materials 0.000 description 4
- 239000011593 sulfur Substances 0.000 description 4
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 3
- 238000011156 evaluation Methods 0.000 description 3
- 229940085991 phosphate ion Drugs 0.000 description 3
- 238000006555 catalytic reaction Methods 0.000 description 2
- 239000003638 chemical reducing agent Substances 0.000 description 2
- 238000011065 in-situ storage Methods 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 239000003921 oil Substances 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 238000004064 recycling Methods 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- 238000010998 test method Methods 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 238000000889 atomisation Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000004737 colorimetric analysis Methods 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 239000011552 falling film Substances 0.000 description 1
- 239000010408 film Substances 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 238000009616 inductively coupled plasma Methods 0.000 description 1
- 238000001095 inductively coupled plasma mass spectrometry Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 229920002120 photoresistant polymer Polymers 0.000 description 1
- 239000012286 potassium permanganate Substances 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 230000001172 regenerating effect Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000010802 sludge Substances 0.000 description 1
- 238000004448 titration Methods 0.000 description 1
- 238000007738 vacuum evaporation Methods 0.000 description 1
- 239000002918 waste heat Substances 0.000 description 1
- 239000002351 wastewater Substances 0.000 description 1
Classifications
-
- 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
- C01B17/90—Separation; Purification
-
- 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
- C01B17/48—Sulfur dioxide; Sulfurous acid
- C01B17/50—Preparation of sulfur dioxide
- C01B17/58—Recovery of sulfur dioxide from acid tar or the like or from any waste sulfuric acid
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
A method for preparing high-purity electronic-grade sulfuric acid from waste sulfuric acid solution comprises the steps of S1 to S7, particularly step S5, in a demisting device comprising at least two demisters mutually connected in series, acid mist containing metal ions and carried by sulfur trioxide gas with first purity is removed, and sulfur trioxide gas with second purity is obtained, each demister comprises a filler unit with a bearing frame and a filler filled in the bearing frame, the bearing frame is made of at least one of PFA and M-PTFE, the filler is made of PFA or M-PTFE, and the waste sulfuric acid solution can be regenerated to prepare the high-purity electronic-grade sulfuric acid, and the prepared high-purity electronic-grade sulfuric acid is particularly suitable for semiconductor manufacturing processes.
Description
Technical Field
The invention relates to a method for recycling a waste sulfuric acid solution, in particular to a method for preparing high-purity electronic-grade sulfuric acid by using the waste sulfuric acid solution.
Background
In the semiconductor industry, in order to remove organic substances such as chemicals and photoresist remaining on the surface of a silicon chip in a front-end process, a large amount of mixed solution containing electronic-grade sulfuric acid and hydrogen peroxide is used for cleaning, and a large amount of waste sulfuric acid solution is generated. If the waste sulfuric acid solution is discharged without proper treatment, it will cause pollution and harm to the environment. In addition, with the explosion of the semiconductor industry, the usage amount of electronic grade sulfuric acid is increased, which means that a large amount of waste sulfuric acid solution is generated continuously. Therefore, how to effectively treat the waste sulfuric acid solution is an important issue to be solved at present.
Disclosure of Invention
The invention aims to provide a method for preparing high-purity electronic-grade sulfuric acid from waste sulfuric acid solution by recycling the waste sulfuric acid solution.
The invention discloses a method for preparing high-purity electronic-grade sulfuric acid by using a waste sulfuric acid solution, which comprises the following steps of:
step S1: sequentially carrying out concentration treatment, cracking treatment and purification treatment on the waste sulfuric acid solution to obtain pure sulfur dioxide gas;
step S2: oxidizing said pure sulfur dioxide gas to sulfur trioxide gas in the presence of a catalyst to obtain a gaseous product comprising sulfur trioxide gas;
and step S3: absorbing sulfur trioxide gas and residual pure sulfur dioxide gas in the gas product by using oleum with first concentration to obtain oleum with second concentration, oxidizing the residual sulfur dioxide in the oleum with second concentration into sulfur trioxide by using an oxidant to form oleum with third concentration, wherein the relationship of the concentrations of the oleum with first concentration, the oleum with second concentration and the sulfur trioxide in the oleum with third concentration is that the oleum with second concentration and the oleum with third concentration are larger than the oleum with first concentration;
and step S4: subjecting the oleum having the third concentration to an evaporation treatment at an evaporation temperature of 130 ℃ to 150 ℃ to extract sulfur trioxide gas from the oleum having the third concentration to obtain sulfur trioxide gas having a first purity;
step S5: removing acid mist containing metal ions entrained by the sulfur trioxide gas with the first purity in a demisting device to obtain sulfur trioxide gas with a second purity, wherein the purity of sulfur trioxide in the sulfur trioxide gas with the second purity is greater than that of sulfur trioxide in the sulfur trioxide gas with the first purity, the demisting device comprises at least two demisters which are connected in series, each demister comprises a filler unit, each filler unit comprises a bearing frame and a filler supported by the bearing frame, the bearing frame is made of at least one of tetrafluoroethylene-perfluoroalkoxy vinyl ether copolymer and modified polytetrafluoroethylene, and the filler is made of tetrafluoroethylene-perfluoroalkoxy vinyl ether copolymer or modified polytetrafluoroethylene;
step S6: absorbing the sulfur trioxide gas with second purity by electronic-grade sulfuric acid with first purity to obtain electronic-grade sulfuric acid with second purity, wherein the concentration of sulfuric acid in the electronic-grade sulfuric acid with second purity is greater than that in the electronic-grade sulfuric acid with first purity; and
step S7: removing residual sulfur dioxide in the electronic-grade sulfuric acid with the second purity to obtain electronic-grade sulfuric acid with a third purity, wherein the concentration of sulfuric acid in the electronic-grade sulfuric acid with the third purity is greater than that in the electronic-grade sulfuric acid with the second purity.
In the method for preparing high-purity electronic-grade sulfuric acid from waste sulfuric acid solution, in the step S5, the filler is in a silk-net shape or a 3D honeycomb shape, and the specific surface area of the filler is 200m 2 /m 3 To 2000m 2 /m 3 。
In the method for preparing high-purity electronic-grade sulfuric acid from waste sulfuric acid solution, in the step S1, the concentration treatment includes concentrating the waste sulfuric acid solution in a vacuum environment to obtain a concentrated waste sulfuric acid solution with a sulfuric acid concentration greater than that of the waste sulfuric acid solution.
In the method for preparing high-purity electronic-grade sulfuric acid from waste sulfuric acid solution, in the step S1, the cracking treatment includes atomizing the concentrated waste sulfuric acid solution to form fog drops, and then performing a cracking reaction at 1000 to 1200 ℃ for 1.5 to 3.5 seconds to obtain a mixed gas containing sulfur dioxide gas, oxygen and water vapor.
In the method for preparing high-purity electronic-grade sulfuric acid from waste sulfuric acid solution, in the step S1, the purification treatment includes cooling the mixed gas from 1000 ℃ to 1200 ℃ to 300 ℃ to 400 ℃, and then purifying and cooling the mixed gas to below 40 ℃ to obtain pure sulfur dioxide gas.
In the method for preparing high-purity electronic-grade sulfuric acid from the waste sulfuric acid solution, in the step S2, the catalyst is selected from vanadium pentoxide.
In the method for preparing high-purity electronic-grade sulfuric acid from a waste sulfuric acid solution according to the present invention, in the step S3, the oxidizing agent is at least one selected from hydrogen peroxide, sodium persulfate and ozone.
In the method for preparing high-purity electronic-grade sulfuric acid from waste sulfuric acid solution, in the step S7, the concentration of the electronic-grade sulfuric acid with the second purity is adjusted by using ultrapure water, and then the electronic-grade sulfuric acid with the third purity is obtained by firstly cooling and reducing the temperature and then removing sulfur dioxide by using compressed dry air without oil and dust.
In the method for preparing high-purity electronic-grade sulfuric acid from waste sulfuric acid solution, in the step S7, the electronic-grade sulfuric acid with the third purity is obtained by oxidizing the residual sulfur dioxide in the electronic-grade sulfuric acid with the electronic-grade hydrogen peroxide and then filtering.
In the method for preparing high-purity electronic-grade sulfuric acid from a waste sulfuric acid solution according to the present invention, in step S7, the filtration is performed in a filter comprising at least three filter elements, wherein the filter elements are connected in series, each filter element has a pore size ranging from 0.003 μm to 0.1 μm, and the material of each filter element comprises at least one of tetrafluoroethylene-perfluoroalkoxy vinyl ether copolymer and modified polytetrafluoroethylene.
The invention has the beneficial effects that: through the mutual matching of the steps S1 to S7, particularly the demisting device used in the step S5 comprises at least two demisters which are connected in series, and the filler made of a specific material is filled in each demister, so that the waste sulfuric acid solution can be effectively regenerated to prepare high-purity electronic-grade sulfuric acid, and the high-purity electronic-grade sulfuric acid is particularly suitable for semiconductor manufacturing processes.
Detailed Description
The invention relates to a method for preparing high-purity electronic-grade sulfuric acid by using a waste sulfuric acid solution, in particular to a method for preparing the high-purity electronic-grade sulfuric acid by regenerating the waste sulfuric acid solution generated in a semiconductor manufacturing process.
As used herein, the term "spent sulfuric acid solution" refers generally to sulfuric acid-containing spent solutions generated during semiconductor processing. In addition to sulfuric acid and water, the waste sulfuric acid solution may also contain chemicals used in semiconductor processing, such as, but not limited to, hydrogen peroxide, and residues thereof. The concentration of sulfuric acid in the waste sulfuric acid solution is not particularly limited, and for example, in the case of a waste sulfuric acid solution generated in a general semiconductor manufacturing process, the concentration of sulfuric acid in the waste sulfuric acid solution is 40wt% to 75wt%.
The first embodiment of the method for preparing high-purity electronic-grade sulfuric acid by using the waste sulfuric acid solution comprises the following steps:
step S1: and sequentially carrying out concentration treatment, cracking treatment and purification treatment on the waste sulfuric acid solution to obtain pure sulfur dioxide gas.
The concentration treatment comprises concentrating the waste sulfuric acid solution in a vacuum environment to obtain a concentrated waste sulfuric acid solution with sulfuric acid concentration greater than that of the waste sulfuric acid solution. For example, the concentration of sulfuric acid in the concentrated waste sulfuric acid solution obtained by performing the concentration may be 80wt% to 90wt% in the case where the concentration of sulfuric acid in the waste sulfuric acid solution is 40wt% to 75wt%. The method for concentrating the waste sulfuric acid solution is not particularly limited, and for example, but not limited to, the waste sulfuric acid solution is heated and evaporated in a vacuum environment by using a vacuum evaporation device to concentrate. The hydrogen peroxide vapor and the water vapor generated in the condensation are introduced into a condensing device and condensed to form an aqueous hydrogen peroxide solution.
The cracking treatment comprises atomizing the concentrated waste sulfuric acid solution to form fog drops, and then carrying out cracking reaction at 1000-1200 ℃ for 1.5-3.5 seconds to obtain a mixed gas containing sulfur dioxide gas, oxygen and water vapor. The manner in which the concentrated spent sulfuric acid solution is atomized to form droplets is not particularly limited, for example, but not limited to, atomizing the concentrated spent sulfuric acid solution to form droplets using a two-fluid atomization spray gun with air at a pressure ranging from 0.3MPa to 0.6 MPa. The manner of carrying out the cracking reaction is not particularly limited, for example, but not limited to, introducing the droplets into a cracking furnace, and introducing natural gas or sulfur into the cracking furnace to generate the heat energy required for the droplets to carry out the cracking reaction.
The purification treatment comprises the steps of cooling the mixed gas from 1000-1200 ℃ to 300-400 ℃, purifying the mixed gas and cooling the mixed gas to below 40 ℃ to obtain pure sulfur dioxide gas. The way of reducing the temperature of the mixed gas from 1000 ℃ to 1200 ℃ to 300 ℃ to 400 ℃ is not particularly limited, and for example, but not limited to, the mixed gas is reduced in temperature by recovering high-temperature heat energy of the mixed gas using one waste heat boiler to generate steam. The way of purifying and cooling the mixed gas to below 40 ℃ is not particularly limited, for example, but not limited to, introducing the mixed gas cooled to 300 ℃ to 400 ℃ into a reverse spray scrubber to further cool the mixed gas and remove the uncracked concentrated waste sulfuric acid solution, the incompletely cracked sulfur trioxide gas, and the refractory sludge from the cracking furnace, etc. in the mixed gas to obtain pure sulfur dioxide gas.
Step S2: oxidizing said pure sulfur dioxide gas to sulfur trioxide gas in the presence of a catalyst to produce a gaseous product comprising sulfur trioxide gas. In some embodiments of the present invention, the pure sulfur dioxide gas is introduced into a catalytic reaction tower filled with the catalyst, and air is introduced into the catalytic reaction tower to oxidize the pure sulfur dioxide gas into sulfur trioxide gas. The catalyst may be of the type typically used to convert sulfur dioxide to sulfur trioxide, such as, but not limited to, vanadium pentoxide, and the like.
And step S3: absorbing sulfur trioxide gas in the gas product and residual pure sulfur dioxide gas by using oleum with first concentration to obtain oleum with second concentration, oxidizing residual sulfur dioxide in the oleum with second concentration into sulfur trioxide by using an oxidizing agent to form oleum with third concentration, wherein the concentrations of sulfur trioxide in the oleum with first concentration, the oleum with second concentration and the oleum with third concentration are in a relation that the oleum with second concentration and the oleum with third concentration are greater than that of the oleum with first concentration. In some embodiments of the present invention, the step S3 is performed in an absorption tower filled with the oleum having the first concentration and an oxidant, such as but not limited to hydrogen peroxide, sodium persulfate, ozone, etc., is added to oxidize the sulfur dioxide remaining in the oleum having the second concentration to sulfur trioxide, wherein the oxidant can be used singly or in combination. In addition, the exhaust gas produced during the absorption of the gaseous product by the oleum having the first concentration is passed through an exhaust gas absorption tower to recover sulfur trioxide gas from the exhaust gas. It is noted that the terms "fuming sulfuric acid having a first concentration", "fuming sulfuric acid having a second concentration", and "fuming sulfuric acid having a third concentration" are intended to mean the high and low levels of the sulfur trioxide concentration in the fuming sulfuric acid, and the concentrations of sulfur trioxide in the fuming sulfuric acid having the first concentration, the fuming sulfuric acid having the second concentration, and the fuming sulfuric acid having the third concentration are not particularly limited, for example, but not limited to, the sulfur trioxide concentration in the fuming sulfuric acid having the second concentration ranges from 25wt% to 40wt% and the sulfur dioxide concentration ranges from 5ppm to 50ppm, and the sulfur trioxide concentration in the fuming sulfuric acid having the third concentration ranges from 25wt% to 40wt% and the sulfur dioxide concentration ranges from 0ppm to 0.5ppm.
And step S4: subjecting the oleum having the third concentration to an evaporation process at an evaporation temperature of 130 ℃ to 150 ℃ to extract sulfur trioxide gas from the oleum having the third concentration to obtain sulfur trioxide gas having the first purity. The evaporation treatment is carried out by introducing the fuming sulfuric acid having the third concentration into an evaporator such as, but not limited to, a rising film evaporator or a falling film evaporator via a preheater. Further, the oleum having the third concentration remaining after the evaporation treatment may be returned to the absorption tower via the preheater as necessary.
It is worth mentioning that the evaporation temperature of the evaporation treatment is controlled to 130 ℃ to 150 ℃, so that the situation that the evaporator is corroded by acid to cause metal dissolution can be avoided.
Step S5: and removing the acid mist containing the metal ions carried by the sulfur trioxide gas with the first purity in a demisting device to obtain the sulfur trioxide gas with the second purity, wherein the sulfur trioxide purity in the sulfur trioxide gas with the second purity is greater than that in the sulfur trioxide gas with the first purity.
The demister apparatus comprises at least two demisters connected in series with each other, and each demister comprises a packing unit. The packing unit is provided with a bearing frame and a packing filled in the bearing frame. The bearing frame is made of at least one of tetrafluoroethylene-perfluoroalkoxy vinyl ether copolymer (PFA) and modified polytetrafluoroethylene (M-PTFE). The material of the filler is selected from tetrafluoroethylene-perfluoroalkoxy vinyl ether copolymer or modified polytetrafluoroethylene. The filler material of the filler units in each demister can be the same or different. Preferably, the filler is in the shape of a wire mesh or a 3D honeycomb, and the specific surface area of the filler ranges from 200m 2 /m 3 To 2000m 2 /m 3 。
Step S6: absorbing the sulfur trioxide gas with the second purity by using electronic-grade sulfuric acid with the first purity to obtain electronic-grade sulfuric acid with the second purity, wherein the concentration of sulfuric acid in the electronic-grade sulfuric acid with the second purity is greater than that in the electronic-grade sulfuric acid with the first purity. In some embodiments of the invention, step S6 is performed in an absorption tower filled with the electronic grade sulfuric acid having the first purity.
Step S7: removing residual sulfur dioxide in the electronic-grade sulfuric acid with the second purity to obtain electronic-grade sulfuric acid with a third purity, wherein the concentration of sulfuric acid in the electronic-grade sulfuric acid with the third purity is greater than that in the electronic-grade sulfuric acid with the second purity. In step S7 of the first embodiment, the electronic-grade sulfuric acid with the second purity is adjusted in concentration by ultra-pure water, and then cooled and then residual sulfur dioxide is removed by Compressed Dry Air (CDA) without oil and dust, thereby obtaining the electronic-grade sulfuric acid with the third purity.
The second embodiment of the method for preparing high-purity electronic-grade sulfuric acid from a waste sulfuric acid solution of the present invention is different from the first embodiment in that in step S7 of the second embodiment, the electronic-grade sulfuric acid with the third purity is obtained by oxidizing the sulfur dioxide remaining in the electronic-grade sulfuric acid with electronic-grade hydrogen peroxide and then filtering the oxidized sulfur dioxide. Wherein the filtration is carried out in a filter comprising at least three filter elements, said filter elements being connected in series. The aperture of each filter element ranges from 0.003 mu M to 0.1 mu M, and the material of each filter element comprises at least one of tetrafluoroethylene-perfluoroalkoxy vinyl ether copolymer (PFA) and modified polytetrafluoroethylene (M-PTFE).
The invention will be further described in the following specific examples, but it should be understood that the examples are for illustrative purposes only and should not be construed as limiting the practice of the invention.
[ examples 1 to 3]
Examples 1 to 3 are processes for treating a spent sulfuric acid solution according to the steps of the first example described above to produce electronic grade sulfuric acid having a third purity. The process parameter conditions for examples 1 to 3 are shown in table 1 below.
[ Property evaluation ]
The test method of each property evaluation item will be described below by taking example 1 as an example, and the other examples are analyzed in the same test method, and the results of the property evaluation are shown in tables 1 and 2.
And (3) analyzing the sulfuric acid content and the hydrogen peroxide content in the waste sulfuric acid solution and the concentrated waste sulfuric acid solution: measuring the waste sulfuric acid solution and the concentrated waste sulfuric acid solution by an automatic titrator to obtain the sulfuric acid content and the hydrogen peroxide content in the waste sulfuric acid solution and the concentrated waste sulfuric acid solution.
Analyzing the total organic carbon content in the waste sulfuric acid solution and the concentrated waste sulfuric acid solution: and measuring the waste sulfuric acid solution and the concentrated waste sulfuric acid solution by using a total organic carbon analyzer to obtain the total organic carbon content in the waste sulfuric acid solution and the concentrated waste sulfuric acid solution.
Analyzing the water content in the waste sulfuric acid solution and the concentrated waste sulfuric acid solution: and deducting the measured sulfuric acid content, hydrogen peroxide content and total organic carbon content in the waste sulfuric acid solution by taking the total amount of the waste sulfuric acid solution as 100wt%, thereby obtaining the water content in the waste sulfuric acid solution. The water content in the concentrated waste sulfuric acid solution is obtained in the same manner, and will not be described in detail.
Oxygen content in the mixed gas of gases containing sulfur dioxide: the oxygen content of the mixed gas containing sulfur dioxide gas in example 1 was measured in situ (in-situ) by an oxygen analyzer.
Sulfur recovery rate of the purification treatment of step S1: (sulfur content in waste sulfuric acid solution-sulfur content in wastewater produced by purification treatment). This content in waste sulfuric acid solution X100%.
Sulfur dioxide conversion in step S2: (content of pure sulfur dioxide gas-sulfur dioxide gas content in the gas product containing sulfur trioxide gas) ÷ content of pure sulfur dioxide gas x 100%.
Sulfur trioxide absorption rate of step S3: (sulfur trioxide gas content in the gaseous product containing sulfur trioxide gas-sulfur trioxide content in the exhaust gas). This sulfur trioxide gas content in the gaseous product containing sulfur trioxide gas X100%.
Purity: the purity of the electronic grade sulfuric acid having the third purity of example 1 was measured by an automatic titrator according to the analytical method of JIS K9905 (1995 edition).
Colorimetric analysis of electronic grade sulfuric acid: the color of the electronic grade sulfuric acid of example 1 having the third purity was measured using a color scale tube having a standard color, using a guidance for analyzing SEMI C1-0310 (2010 version) liquid chemicals.
Ignition residue content analysis: the ignition residue content in electronic grade sulfuric acid having the third purity of example 1 was measured by a method for analyzing high purity sulfuric acid according to JIS K9905 (1995 edition) using a high temperature furnace and a precision balance.
Analysis of content of reducing substances: the content of the reducing substance in the electronic grade sulfuric acid having the third purity of example 1 was obtained by an analytical method of JIS K9905 (1995 edition) high-purity sulfuric acid, and redox titration was performed on the electronic grade sulfuric acid having the third purity of example 1 using potassium permanganate, and then the molecular weight of sulfur dioxide was used as a basis for calculation of the content of the reducing substance in the electronic grade sulfuric acid having the third purity of example 1.
And (3) analyzing the ammonium ion content: according to the analytical method of JIS K9905 (1995 edition) high-purity sulfuric acid, a plurality of electronic-grade sulfuric acid standard products with known ammonium ion content are taken, reaction reagents are utilized to react with ammonium ions in each electronic-grade sulfuric acid standard product, the absorbance of each reacted electronic-grade sulfuric acid standard product is measured by an ultraviolet-visible spectrophotometer, and the absorbance and the ammonium ion content of all the reacted electronic-grade sulfuric acid standard products are made into a detection line, so that a linear equation is obtained. Next, the reaction reagent is added to the electronic grade sulfuric acid with the third purity of example 1, and the reaction reagent reacts with the ammonium ions in the electronic grade sulfuric acid with the third purity of example 1 to obtain a solution to be tested, the ultraviolet-visible spectrophotometer is used to measure the absorbance of the solution to be tested, and the linear equation is used to calculate the ammonium ion content in the electronic grade sulfuric acid with the third purity of example 1.
Analyzing the content of chloride ions: according to an analytical method of JIS K9905 (1995 edition) high-purity sulfuric acid, a plurality of electronic-grade sulfuric acid standard products containing known chloride ion content are taken, reaction reagents are utilized to react with chloride ions in each electronic-grade sulfuric acid standard product, the turbidity of each reacted electronic-grade sulfuric acid standard product is measured by a turbidity meter, and the turbidity and the chloride ion content of all the reacted electronic-grade sulfuric acid standard products are made into detection lines, so that a linear equation is obtained. Next, the reaction reagent is added to the electronic-grade sulfuric acid with the third purity of example 1, and the reaction reagent reacts with the chloride ions in the electronic-grade sulfuric acid with the third purity of example 1 to obtain a solution to be measured, and the turbidity of the solution to be measured is measured by the turbidity meter, and the content of the chloride ions in the electronic-grade sulfuric acid with the third purity of example 1 is calculated by the linear equation.
Nitrate ion content analysis: according to the analytical method of JIS K9905 (1995 edition) high-purity sulfuric acid, a plurality of electronic-grade sulfuric acid standard products containing known nitrate ion content are taken, the absorbance of each electronic-grade sulfuric acid standard product is measured by an ultraviolet-visible spectrophotometer, and the absorbance of all electronic-grade sulfuric acid standard products and the nitrate ion content are made into a detection line, so that a linear equation is obtained. Next, the ultraviolet-visible spectrophotometer is used to measure the absorbance of the electronic grade sulfuric acid with the third purity of example 1, and the linear equation is used to calculate the nitrate ion content in the electronic grade sulfuric acid with the third purity of example 1.
Analysis of phosphate ion content: according to an analytical method of JIS K9905 (1995 edition) high-purity sulfuric acid, a plurality of electronic-grade sulfuric acid standard products containing known phosphate ion content are taken, a reaction reagent is used for reacting with phosphate ions in each electronic-grade sulfuric acid standard product, an ultraviolet-visible spectrophotometer is used for measuring the absorbance of each reacted electronic-grade sulfuric acid standard product, and the absorbance of all reacted electronic-grade sulfuric acid standard products and the phosphate ion content are made into a detection line to obtain a linear equation. Next, the reaction reagent is added to the electronic grade sulfuric acid with the third purity of example 1, and the reaction reagent reacts with phosphate ions in the electronic grade sulfuric acid with the third purity of example 1 to obtain a solution to be tested, and the absorbance of the solution to be tested is measured by the uv-vis spectrometer, and the content of phosphate ions in the electronic grade sulfuric acid with the third purity of example 1 is calculated by the linear equation.
Analysis of total organic carbon: the total organic carbon content of the electronic grade sulfuric acid with the third purity of example 1 was measured by a total organic carbon analyzer under the condition of high temperature catalytic oxidation with non-dispersive infrared (NDIR).
And (3) analyzing the content of metal ions: the metal ion content of the electronic grade sulfuric acid having the third purity of example 1 was analyzed using an inductively coupled plasma mass spectrometer (manufacturer: agilent; model: ICP-MS 8900).
TABLE 1
Referring to table 1, the processes of examples 1 to 3 for preparing high purity electronic-grade sulfuric acid from waste sulfuric acid solutions have a conversion rate of sulfur dioxide of 99.85% or more and an absorption rate of sulfur trioxide of 99.95% or more, which indicates that the processes of examples 1 to 3 can effectively convert sulfur dioxide into sulfur trioxide, and the sulfur trioxide can be effectively absorbed by oleum having a first concentration and then subsequently prepared into electronic-grade sulfuric acid having a third purity through steps S4 to S7, and the concentration of the electronic-grade sulfuric acid having the third purity is as high as 96% or more.
TABLE 2
Referring to table 2, it can be seen from the results of the metal ion content analysis of examples 1 to 3 that the content of each metal ion in the electronic grade sulfuric acid having the third purity of examples 1 to 3 was less than 5ppt. It is worth mentioning that according to the current classification standard of the industry for the purity of electronic grade sulfuric acid, when the content of metal ions in the electronic grade sulfuric acid is less than 10ppt, the electronic grade sulfuric acid is classified as the highest purity electronic grade sulfuric acid, and the highest purity electronic grade sulfuric acid is particularly suitable for the semiconductor process with the line width less than 10 nm, so that the content of metal ions in the electronic grade sulfuric acid with the third purity of examples 1 to 3 meets the current classification standard of the industry for the highest purity electronic grade sulfuric acid.
In summary, the method for preparing high-purity electronic-grade sulfuric acid from waste sulfuric acid solution of the present invention is characterized in that steps S1 to S7 are matched, and particularly, the demister used in step S5 comprises at least two mist eliminators connected in series, and each mist eliminator is filled with the filler made of a specific material, so that the waste sulfuric acid solution can be effectively regenerated to prepare high-purity electronic-grade sulfuric acid.
However, the above description is only an example of the present invention, and the scope of the present invention should not be limited thereby, and all simple equivalent changes and modifications made according to the claims and the contents of the specification should be included in the scope of the present invention.
Claims (10)
1. A method for preparing high-purity electronic-grade sulfuric acid from a waste sulfuric acid solution is characterized by comprising the following steps:
step S1: sequentially carrying out concentration treatment, cracking treatment and purification treatment on the waste sulfuric acid solution to obtain pure sulfur dioxide gas;
step S2: oxidizing said pure sulfur dioxide gas to sulfur trioxide gas in the presence of a catalyst to obtain a gaseous product comprising sulfur trioxide gas;
and step S3: absorbing sulfur trioxide gas and residual pure sulfur dioxide gas in the gas product by using oleum with first concentration to obtain oleum with second concentration, oxidizing the residual sulfur dioxide in the oleum with second concentration into sulfur trioxide by using an oxidant to form oleum with third concentration, wherein the relationship of the concentrations of the oleum with first concentration, the oleum with second concentration and the sulfur trioxide in the oleum with third concentration is that the oleum with second concentration and the oleum with third concentration are larger than the oleum with first concentration;
and step S4: subjecting the oleum having the third concentration to an evaporation treatment at an evaporation temperature of 130 ℃ to 150 ℃ to extract sulfur trioxide gas from the oleum having the third concentration to obtain sulfur trioxide gas having a first purity;
step S5: removing acid mist containing metal ions entrained by the sulfur trioxide gas with the first purity in a demisting device to obtain sulfur trioxide gas with a second purity, wherein the purity of sulfur trioxide in the sulfur trioxide gas with the second purity is greater than that of sulfur trioxide in the sulfur trioxide gas with the first purity, the demisting device comprises at least two demisters connected in series, each demister comprises a packing unit, each packing unit comprises a bearing frame and packing filled in the bearing frame, the bearing frame is made of at least one of tetrafluoroethylene-perfluoroalkoxy vinyl ether copolymer and modified polytetrafluoroethylene, and the packing is made of tetrafluoroethylene-perfluoroalkoxy vinyl ether copolymer or modified polytetrafluoroethylene;
step S6: absorbing the sulfur trioxide gas with second purity by electronic-grade sulfuric acid with first purity to obtain electronic-grade sulfuric acid with second purity, wherein the concentration of sulfuric acid in the electronic-grade sulfuric acid with second purity is greater than that in the electronic-grade sulfuric acid with first purity; and
step S7: removing residual sulfur dioxide in the electronic-grade sulfuric acid with the second purity to obtain electronic-grade sulfuric acid with a third purity, wherein the concentration of sulfuric acid in the electronic-grade sulfuric acid with the third purity is greater than that in the electronic-grade sulfuric acid with the second purity.
2. The method for preparing high-purity electronic-grade sulfuric acid from a waste sulfuric acid solution as claimed in claim 1, wherein: in the step S5, the filler has a wire mesh shape or a 3D honeycomb shape, and has a specific surface area ranging from 200m 2 /m 3 To 2000m 2 /m 3 。
3. The method for preparing high-purity electronic-grade sulfuric acid from a waste sulfuric acid solution as claimed in claim 1, wherein: in the step S1, the concentration treatment includes concentrating the waste sulfuric acid solution in a vacuum environment to obtain a concentrated waste sulfuric acid solution having a sulfuric acid concentration greater than that of the waste sulfuric acid solution.
4. The method of claim 3 for preparing high purity electronic grade sulfuric acid from spent sulfuric acid solution, wherein: in the step S1, the cracking treatment includes atomizing the concentrated waste sulfuric acid solution to form droplets, and then performing a cracking reaction at 1000 to 1200 ℃ for 1.5 to 3.5 seconds to obtain a mixed gas containing sulfur dioxide gas, oxygen and water vapor.
5. The method of claim 4 for preparing high purity electronic grade sulfuric acid from spent sulfuric acid solution, wherein: in the step S1, the purification treatment includes cooling the mixed gas from 1000 ℃ to 1200 ℃ to 300 ℃ to 400 ℃, and then purifying and cooling the mixed gas to below 40 ℃ to obtain pure sulfur dioxide gas.
6. The method for preparing high-purity electronic-grade sulfuric acid from a waste sulfuric acid solution as claimed in claim 1, wherein: in step S2, the catalyst is selected from vanadium pentoxide.
7. The method for preparing high-purity electronic-grade sulfuric acid from a waste sulfuric acid solution as claimed in claim 1, wherein: in the step S3, the oxidizing agent is at least one selected from the group consisting of hydrogen peroxide, sodium persulfate, and ozone.
8. The method for preparing high-purity electronic-grade sulfuric acid from a waste sulfuric acid solution as claimed in claim 1, wherein: in the step S7, after the concentration of the electronic-grade sulfuric acid having the second purity is adjusted by ultrapure water, the electronic-grade sulfuric acid having the third purity is obtained by cooling and then removing sulfur dioxide by using compressed dry air containing no oil or dust.
9. The method for preparing high-purity electronic-grade sulfuric acid from a waste sulfuric acid solution as claimed in claim 1, wherein: in step S7, the residual sulfur dioxide in the electronic grade sulfuric acid with the second purity is oxidized by electronic grade hydrogen peroxide, and then filtered to obtain the electronic grade sulfuric acid with the third purity.
10. The method for preparing high-purity electronic-grade sulfuric acid from a waste sulfuric acid solution as claimed in claim 9, wherein: in the step S7, the filtering is performed in a filter comprising at least three filter elements connected in series, each filter element has a pore size ranging from 0.003 μm to 0.1 μm, and the material of each filter element comprises at least one of a tetrafluoroethylene-perfluoroalkylvinylether copolymer and a modified polytetrafluoroethylene.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110724762.6A CN115535971B (en) | 2021-06-29 | 2021-06-29 | Method for preparing high-purity electronic grade sulfuric acid from waste sulfuric acid solution |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110724762.6A CN115535971B (en) | 2021-06-29 | 2021-06-29 | Method for preparing high-purity electronic grade sulfuric acid from waste sulfuric acid solution |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115535971A true CN115535971A (en) | 2022-12-30 |
| CN115535971B CN115535971B (en) | 2024-02-09 |
Family
ID=84717497
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110724762.6A Active CN115535971B (en) | 2021-06-29 | 2021-06-29 | Method for preparing high-purity electronic grade sulfuric acid from waste sulfuric acid solution |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115535971B (en) |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH1095603A (en) * | 1996-09-24 | 1998-04-14 | Mitsui Eng & Shipbuild Co Ltd | Recovery of sulfuric acid from waste sulfuric acid and apparatus for recovering sulfuric acid |
| US20020192144A1 (en) * | 1999-12-28 | 2002-12-19 | Martin Hostalek | Method for producing high-purity sulphuric acid |
| DE10257093A1 (en) * | 2002-12-05 | 2004-07-08 | Basf Ag | Aerosol separator, especially for purifying sulfur trioxide gas to give a product which can be used in production of electronic-grade sulfuric acid, has a wall of partly perfluoroalkoxylated polytetrafluoroethylene |
| CN105565281A (en) * | 2016-02-16 | 2016-05-11 | 韩功篑 | Preparation method for hyperpure sulphuric acid |
| CN105621374A (en) * | 2016-02-16 | 2016-06-01 | 江苏达诺尔科技股份有限公司 | Preparation method of ultra-pure sulfuric acid |
| CN112174165A (en) * | 2019-07-03 | 2021-01-05 | 强方投顾股份有限公司 | Semiconductor grade ammonia water and sulfuric acid recovery and circulation manufacturing method |
| CN112441567A (en) * | 2021-01-04 | 2021-03-05 | 联仕(昆山)化学材料有限公司 | Production process of electronic-grade sulfuric acid and low-temperature evaporation, purification and absorption device for production |
| CN112850657A (en) * | 2021-02-06 | 2021-05-28 | 岷山环能高科股份公司 | Flue gas separation and purification system for producing electronic-grade sulfuric acid |
| CN112897474A (en) * | 2021-02-06 | 2021-06-04 | 岷山环能高科股份公司 | Sulfur trioxide purifying device |
-
2021
- 2021-06-29 CN CN202110724762.6A patent/CN115535971B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH1095603A (en) * | 1996-09-24 | 1998-04-14 | Mitsui Eng & Shipbuild Co Ltd | Recovery of sulfuric acid from waste sulfuric acid and apparatus for recovering sulfuric acid |
| US20020192144A1 (en) * | 1999-12-28 | 2002-12-19 | Martin Hostalek | Method for producing high-purity sulphuric acid |
| DE10257093A1 (en) * | 2002-12-05 | 2004-07-08 | Basf Ag | Aerosol separator, especially for purifying sulfur trioxide gas to give a product which can be used in production of electronic-grade sulfuric acid, has a wall of partly perfluoroalkoxylated polytetrafluoroethylene |
| CN105565281A (en) * | 2016-02-16 | 2016-05-11 | 韩功篑 | Preparation method for hyperpure sulphuric acid |
| CN105621374A (en) * | 2016-02-16 | 2016-06-01 | 江苏达诺尔科技股份有限公司 | Preparation method of ultra-pure sulfuric acid |
| CN112174165A (en) * | 2019-07-03 | 2021-01-05 | 强方投顾股份有限公司 | Semiconductor grade ammonia water and sulfuric acid recovery and circulation manufacturing method |
| CN112441567A (en) * | 2021-01-04 | 2021-03-05 | 联仕(昆山)化学材料有限公司 | Production process of electronic-grade sulfuric acid and low-temperature evaporation, purification and absorption device for production |
| CN112850657A (en) * | 2021-02-06 | 2021-05-28 | 岷山环能高科股份公司 | Flue gas separation and purification system for producing electronic-grade sulfuric acid |
| CN112897474A (en) * | 2021-02-06 | 2021-06-04 | 岷山环能高科股份公司 | Sulfur trioxide purifying device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115535971B (en) | 2024-02-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7118720B1 (en) | Method for combined removal of mercury and nitrogen oxides from off-gas streams | |
| EP3401004A1 (en) | Method for controlling aerosol production during sulfur dioxide absorption with ammonium salts in flue gas desulfurization | |
| US20140286831A1 (en) | SYSTEM FOR TREATING NOx-CONTAINING GAS STREAMS | |
| EP1308198A1 (en) | Mercury removal method and system | |
| PL172804B1 (en) | Flue gas desulfurisation process | |
| FI56933B (en) | FOER REQUIREMENTS | |
| US4107271A (en) | Wet-treatment of exhaust gases | |
| US4454100A (en) | Condensation process for separating air pollutants from waste gases, and specifically from flue gases | |
| FI62002C (en) | REFERENCE FITTING FOR SEPARATION OF A QUANTIFIED HYDROGEN WITH HYDROGEN GASER | |
| US7404938B2 (en) | Emission control system | |
| TWI765711B (en) | Method for preparing high-purity electronic grade sulfuric acid from waste sulfuric acid solution | |
| Liu et al. | Advanced Oxidative Removal of Nitric Oxide from Flue Gas by Homogeneous Photo‐Fenton in a Photochemical Reactor | |
| CS154892A3 (en) | Process for waste sulfuric acid regeneration | |
| US4206189A (en) | Method of producing hydrogen fluoride and silicon dioxide from silicon tetra-fluoride | |
| CA2298233A1 (en) | Process for preparing pure hydrofluoric acid | |
| CN115535971B (en) | Method for preparing high-purity electronic grade sulfuric acid from waste sulfuric acid solution | |
| CN115535970B (en) | Method for preparing high-purity electronic grade sulfuric acid from waste sulfuric acid solution | |
| US5082645A (en) | Waste acid recovery process | |
| TWI765712B (en) | Method for preparing high-purity electronic grade sulfuric acid from waste sulfuric acid solution | |
| Ghriss et al. | NO x scrubbing with H 2 O 2/HNO 3 solutions achieved with a laboratory bubble contactor | |
| CN217549402U (en) | Processing apparatus of high concentration waste gas | |
| Weisweiler et al. | Absorption of NO2/N2O4 in nitric acid | |
| CN115057415A (en) | Production process of high-purity electronic acid | |
| KR100646113B1 (en) | Process for condensation of sulphuric acid vapours to produce sulphuric acid | |
| WO2017073447A1 (en) | Method and system for recovering acidic gas, and method and system for analysis for iron ion |
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 |