CN116812872A - Method and system for continuously recycling iodine from low-grade iodine-containing feed liquid - Google Patents
Method and system for continuously recycling iodine from low-grade iodine-containing feed liquid Download PDFInfo
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- 239000011630 iodine Substances 0.000 title claims abstract description 542
- 229910052740 iodine Inorganic materials 0.000 title claims abstract description 542
- ZCYVEMRRCGMTRW-UHFFFAOYSA-N 7553-56-2 Chemical compound [I] ZCYVEMRRCGMTRW-UHFFFAOYSA-N 0.000 title claims abstract description 529
- 239000007788 liquid Substances 0.000 title claims abstract description 289
- 238000000034 method Methods 0.000 title claims abstract description 89
- 238000004064 recycling Methods 0.000 title claims abstract description 10
- 238000001179 sorption measurement Methods 0.000 claims abstract description 535
- 239000003480 eluent Substances 0.000 claims abstract description 133
- 230000008929 regeneration Effects 0.000 claims abstract description 65
- 238000011069 regeneration method Methods 0.000 claims abstract description 65
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 62
- 239000012459 cleaning agent Substances 0.000 claims abstract description 43
- 238000004458 analytical method Methods 0.000 claims abstract description 41
- XMBWDFGMSWQBCA-UHFFFAOYSA-M iodide Chemical compound [I-] XMBWDFGMSWQBCA-UHFFFAOYSA-M 0.000 claims abstract description 37
- 238000012163 sequencing technique Methods 0.000 claims abstract description 37
- -1 iodide ions Chemical class 0.000 claims abstract description 34
- 238000011084 recovery Methods 0.000 claims abstract description 30
- 238000002425 crystallisation Methods 0.000 claims abstract description 25
- 230000008025 crystallization Effects 0.000 claims abstract description 24
- 238000005831 deiodination reaction Methods 0.000 claims abstract description 23
- 230000001105 regulatory effect Effects 0.000 claims abstract description 17
- 238000010924 continuous production Methods 0.000 claims abstract description 14
- 230000001172 regenerating effect Effects 0.000 claims abstract description 12
- 238000003860 storage Methods 0.000 claims abstract description 12
- 238000010979 pH adjustment Methods 0.000 claims abstract description 9
- 238000007781 pre-processing Methods 0.000 claims abstract description 8
- 239000007800 oxidant agent Substances 0.000 claims description 42
- 230000001590 oxidative effect Effects 0.000 claims description 40
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims description 36
- 239000000243 solution Substances 0.000 claims description 35
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 33
- 230000008569 process Effects 0.000 claims description 33
- 238000003556 assay Methods 0.000 claims description 32
- 239000000969 carrier Substances 0.000 claims description 28
- 238000004140 cleaning Methods 0.000 claims description 27
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 25
- 239000002253 acid Substances 0.000 claims description 25
- 238000006243 chemical reaction Methods 0.000 claims description 25
- 238000002156 mixing Methods 0.000 claims description 24
- 239000000126 substance Substances 0.000 claims description 24
- 238000001914 filtration Methods 0.000 claims description 22
- 238000010992 reflux Methods 0.000 claims description 22
- 239000003513 alkali Substances 0.000 claims description 18
- 239000003795 chemical substances by application Substances 0.000 claims description 18
- 239000003153 chemical reaction reagent Substances 0.000 claims description 17
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 16
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 14
- 230000000694 effects Effects 0.000 claims description 14
- 229910052799 carbon Inorganic materials 0.000 claims description 12
- 239000002244 precipitate Substances 0.000 claims description 12
- PNDPGZBMCMUPRI-UHFFFAOYSA-N iodine Chemical compound II PNDPGZBMCMUPRI-UHFFFAOYSA-N 0.000 claims description 11
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 claims description 10
- 230000007613 environmental effect Effects 0.000 claims description 9
- 238000001556 precipitation Methods 0.000 claims description 9
- 239000003814 drug Substances 0.000 claims description 8
- 239000013049 sediment Substances 0.000 claims description 8
- LPXPTNMVRIOKMN-UHFFFAOYSA-M sodium nitrite Chemical compound [Na+].[O-]N=O LPXPTNMVRIOKMN-UHFFFAOYSA-M 0.000 claims description 8
- GEHJYWRUCIMESM-UHFFFAOYSA-L sodium sulfite Chemical compound [Na+].[Na+].[O-]S([O-])=O GEHJYWRUCIMESM-UHFFFAOYSA-L 0.000 claims description 8
- 239000012527 feed solution Substances 0.000 claims description 7
- 239000003242 anti bacterial agent Substances 0.000 claims description 6
- 229940088710 antibiotic agent Drugs 0.000 claims description 6
- 244000052616 bacterial pathogen Species 0.000 claims description 6
- 238000011068 loading method Methods 0.000 claims description 6
- 150000003839 salts Chemical class 0.000 claims description 6
- 229920000049 Carbon (fiber) Polymers 0.000 claims description 5
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims description 5
- LSNNMFCWUKXFEE-UHFFFAOYSA-N Sulfurous acid Chemical group OS(O)=O LSNNMFCWUKXFEE-UHFFFAOYSA-N 0.000 claims description 5
- 150000007513 acids Chemical class 0.000 claims description 5
- 239000003463 adsorbent Substances 0.000 claims description 5
- 229910000147 aluminium phosphate Inorganic materials 0.000 claims description 5
- 238000013459 approach Methods 0.000 claims description 5
- 239000004917 carbon fiber Substances 0.000 claims description 5
- 230000001276 controlling effect Effects 0.000 claims description 5
- 229910021389 graphene Inorganic materials 0.000 claims description 5
- 230000001788 irregular Effects 0.000 claims description 5
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims description 5
- 229910017604 nitric acid Inorganic materials 0.000 claims description 5
- 239000011347 resin Substances 0.000 claims description 5
- 229920005989 resin Polymers 0.000 claims description 5
- 238000003756 stirring Methods 0.000 claims description 5
- 238000000967 suction filtration Methods 0.000 claims description 5
- 239000012445 acidic reagent Substances 0.000 claims description 4
- 239000002585 base Substances 0.000 claims description 4
- 238000000354 decomposition reaction Methods 0.000 claims description 4
- 238000010894 electron beam technology Methods 0.000 claims description 4
- 239000000835 fiber Substances 0.000 claims description 4
- 239000012528 membrane Substances 0.000 claims description 4
- 239000003607 modifier Substances 0.000 claims description 4
- 230000007935 neutral effect Effects 0.000 claims description 4
- 230000003472 neutralizing effect Effects 0.000 claims description 4
- 235000010288 sodium nitrite Nutrition 0.000 claims description 4
- 235000010265 sodium sulphite Nutrition 0.000 claims description 4
- AKHNMLFCWUSKQB-UHFFFAOYSA-L sodium thiosulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=S AKHNMLFCWUSKQB-UHFFFAOYSA-L 0.000 claims description 4
- 235000019345 sodium thiosulphate Nutrition 0.000 claims description 4
- 230000015556 catabolic process Effects 0.000 claims description 3
- 238000006731 degradation reaction Methods 0.000 claims description 3
- 238000010438 heat treatment Methods 0.000 claims description 3
- 239000012080 ambient air Substances 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 abstract description 17
- 239000000463 material Substances 0.000 abstract description 16
- 239000002351 wastewater Substances 0.000 description 15
- 239000007789 gas Substances 0.000 description 12
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 9
- 239000003570 air Substances 0.000 description 8
- 239000002699 waste material Substances 0.000 description 8
- 238000010521 absorption reaction Methods 0.000 description 7
- 238000003795 desorption Methods 0.000 description 7
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 6
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 description 6
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 6
- 238000007664 blowing Methods 0.000 description 6
- 239000012535 impurity Substances 0.000 description 6
- 239000011259 mixed solution Substances 0.000 description 6
- 238000002360 preparation method Methods 0.000 description 6
- 238000002386 leaching Methods 0.000 description 5
- 230000035484 reaction time Effects 0.000 description 5
- 239000007787 solid Substances 0.000 description 5
- 238000000265 homogenisation Methods 0.000 description 4
- XMBWDFGMSWQBCA-UHFFFAOYSA-N hydrogen iodide Chemical compound I XMBWDFGMSWQBCA-UHFFFAOYSA-N 0.000 description 4
- 238000005342 ion exchange Methods 0.000 description 4
- 238000011160 research Methods 0.000 description 4
- YMWUJEATGCHHMB-UHFFFAOYSA-N Dichloromethane Chemical compound ClCCl YMWUJEATGCHHMB-UHFFFAOYSA-N 0.000 description 3
- WMFOQBRAJBCJND-UHFFFAOYSA-M Lithium hydroxide Chemical compound [Li+].[OH-] WMFOQBRAJBCJND-UHFFFAOYSA-M 0.000 description 3
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- 239000013078 crystal Substances 0.000 description 3
- 125000004122 cyclic group Chemical group 0.000 description 3
- 238000007599 discharging Methods 0.000 description 3
- 238000007726 management method Methods 0.000 description 3
- 239000003595 mist Substances 0.000 description 3
- 239000003960 organic solvent Substances 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- 239000002994 raw material Substances 0.000 description 3
- 239000010802 sludge Substances 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- 241000894006 Bacteria Species 0.000 description 2
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 2
- HEDRZPFGACZZDS-UHFFFAOYSA-N Chloroform Chemical compound ClC(Cl)Cl HEDRZPFGACZZDS-UHFFFAOYSA-N 0.000 description 2
- AFVFQIVMOAPDHO-UHFFFAOYSA-N Methanesulfonic acid Chemical compound CS(O)(=O)=O AFVFQIVMOAPDHO-UHFFFAOYSA-N 0.000 description 2
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 2
- RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 description 2
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 2
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical group [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 2
- 229940027989 antiseptic and disinfectant iodine product Drugs 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 239000012267 brine Substances 0.000 description 2
- 239000000460 chlorine Substances 0.000 description 2
- 229910052801 chlorine Inorganic materials 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 238000011437 continuous method Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000005265 energy consumption Methods 0.000 description 2
- 239000003344 environmental pollutant Substances 0.000 description 2
- 238000000605 extraction Methods 0.000 description 2
- 239000000706 filtrate Substances 0.000 description 2
- 230000004907 flux Effects 0.000 description 2
- 230000008676 import Effects 0.000 description 2
- 230000010354 integration Effects 0.000 description 2
- OKJPEAGHQZHRQV-UHFFFAOYSA-N iodoform Chemical compound IC(I)I OKJPEAGHQZHRQV-UHFFFAOYSA-N 0.000 description 2
- 230000005865 ionizing radiation Effects 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 231100000719 pollutant Toxicity 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 230000005855 radiation Effects 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 description 2
- 230000002194 synthesizing effect Effects 0.000 description 2
- JOXIMZWYDAKGHI-UHFFFAOYSA-N toluene-4-sulfonic acid Chemical compound CC1=CC=C(S(O)(=O)=O)C=C1 JOXIMZWYDAKGHI-UHFFFAOYSA-N 0.000 description 2
- XCZXGTMEAKBVPV-UHFFFAOYSA-N trimethylgallium Chemical compound C[Ga](C)C XCZXGTMEAKBVPV-UHFFFAOYSA-N 0.000 description 2
- NWZSZGALRFJKBT-KNIFDHDWSA-N (2s)-2,6-diaminohexanoic acid;(2s)-2-hydroxybutanedioic acid Chemical group OC(=O)[C@@H](O)CC(O)=O.NCCCC[C@H](N)C(O)=O NWZSZGALRFJKBT-KNIFDHDWSA-N 0.000 description 1
- RYHBNJHYFVUHQT-UHFFFAOYSA-N 1,4-Dioxane Chemical compound C1COCCO1 RYHBNJHYFVUHQT-UHFFFAOYSA-N 0.000 description 1
- JKFYKCYQEWQPTM-UHFFFAOYSA-N 2-azaniumyl-2-(4-fluorophenyl)acetate Chemical compound OC(=O)C(N)C1=CC=C(F)C=C1 JKFYKCYQEWQPTM-UHFFFAOYSA-N 0.000 description 1
- BZSXEZOLBIJVQK-UHFFFAOYSA-N 2-methylsulfonylbenzoic acid Chemical compound CS(=O)(=O)C1=CC=CC=C1C(O)=O BZSXEZOLBIJVQK-UHFFFAOYSA-N 0.000 description 1
- JWUJQDFVADABEY-UHFFFAOYSA-N 2-methyltetrahydrofuran Chemical compound CC1CCCO1 JWUJQDFVADABEY-UHFFFAOYSA-N 0.000 description 1
- OSWFIVFLDKOXQC-UHFFFAOYSA-N 4-(3-methoxyphenyl)aniline Chemical compound COC1=CC=CC(C=2C=CC(N)=CC=2)=C1 OSWFIVFLDKOXQC-UHFFFAOYSA-N 0.000 description 1
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- LSNNMFCWUKXFEE-UHFFFAOYSA-M Bisulfite Chemical compound OS([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-M 0.000 description 1
- 206010067997 Iodine deficiency Diseases 0.000 description 1
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 description 1
- 229910021612 Silver iodide Inorganic materials 0.000 description 1
- AUYYCJSJGJYCDS-LBPRGKRZSA-N Thyrolar Chemical class IC1=CC(C[C@H](N)C(O)=O)=CC(I)=C1OC1=CC=C(O)C(I)=C1 AUYYCJSJGJYCDS-LBPRGKRZSA-N 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 239000002250 absorbent Substances 0.000 description 1
- 230000002745 absorbent Effects 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000001476 alcoholic effect Effects 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 235000011114 ammonium hydroxide Nutrition 0.000 description 1
- 239000003963 antioxidant agent Substances 0.000 description 1
- 230000003078 antioxidant effect Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 210000004556 brain Anatomy 0.000 description 1
- 239000002738 chelating agent Substances 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 239000002872 contrast media Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 239000000645 desinfectant Substances 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
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- 238000002848 electrochemical method Methods 0.000 description 1
- 238000010828 elution Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000005188 flotation Methods 0.000 description 1
- 238000011010 flushing procedure Methods 0.000 description 1
- 235000019253 formic acid Nutrition 0.000 description 1
- 231100001261 hazardous Toxicity 0.000 description 1
- IKDUDTNKRLTJSI-UHFFFAOYSA-N hydrazine monohydrate Substances O.NN IKDUDTNKRLTJSI-UHFFFAOYSA-N 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 229940006461 iodide ion Drugs 0.000 description 1
- 150000002496 iodine Chemical class 0.000 description 1
- 235000006479 iodine deficiency Nutrition 0.000 description 1
- 238000011031 large-scale manufacturing process Methods 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
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- 229940098779 methanesulfonic acid Drugs 0.000 description 1
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- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 230000020477 pH reduction Effects 0.000 description 1
- 239000000825 pharmaceutical preparation Substances 0.000 description 1
- 229940127557 pharmaceutical product Drugs 0.000 description 1
- 239000002367 phosphate rock Substances 0.000 description 1
- VKJKEPKFPUWCAS-UHFFFAOYSA-M potassium chlorate Chemical compound [K+].[O-]Cl(=O)=O VKJKEPKFPUWCAS-UHFFFAOYSA-M 0.000 description 1
- 239000003755 preservative agent Substances 0.000 description 1
- 230000002335 preservative effect Effects 0.000 description 1
- 238000002203 pretreatment Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
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- 230000001737 promoting effect Effects 0.000 description 1
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- 239000000700 radioactive tracer Substances 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 238000010405 reoxidation reaction Methods 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 229940045105 silver iodide Drugs 0.000 description 1
- 239000002893 slag Substances 0.000 description 1
- 238000002791 soaking Methods 0.000 description 1
- 238000001694 spray drying Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 238000004659 sterilization and disinfection Methods 0.000 description 1
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 1
- 239000005495 thyroid hormone Substances 0.000 description 1
- 229940036555 thyroid hormone Drugs 0.000 description 1
- 239000011573 trace mineral Substances 0.000 description 1
- 235000013619 trace mineral Nutrition 0.000 description 1
- 238000003828 vacuum filtration Methods 0.000 description 1
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- 239000011701 zinc Substances 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
- 239000011787 zinc oxide Substances 0.000 description 1
Abstract
The invention discloses a method and a system for continuously recycling iodine from low-grade iodine-containing feed liquid, wherein the method comprises the following steps: step one, preprocessing; step two, pH adjustment; step three, regulating iodide ions; step four, iodine adsorption; step five, regenerating the carrier; and step six, iodine recovery. The system comprises an iodine-containing material liquid tank, a pretreatment tank, a filter I, a pH adjusting tank, a filter II, an iodine ion adjusting tank, a pump, a flowmeter, an adsorption tower group, a deiodination material liquid storage tank, an iodine eluent preparing tank, an iodine eluent tank, a water tank, a cleaning agent tank, a crystallization tank, a suction filter and the like. According to the invention, the liquid flow direction is controlled by the valve, so that the front-back sequencing of the adsorption towers is changed, the adsorption towers are programmed with new adsorption sequencing or are withdrawn from adsorption work according to the production sequencing requirement, and the operations of independently completing iodine adsorption, analysis, carrier regeneration, re-use and the like of part of the adsorption towers are realized on the premise of ensuring that the device is not stopped, so that the continuous production of the device is ensured.
Description
Technical Field
The invention belongs to the technical field of iodine recovery, relates to a method and a system for recovering iodine, and in particular relates to a method and a system for continuously recovering iodine from low-grade iodine-containing feed liquid.
Background
According to the research report of deep market research and key areas of the global iodine industry of 2020-2024 issued by the research center of New Si industry, iodine is one of essential trace elements of human body, is a main raw material for synthesizing thyroid hormone, and has an important effect on promoting the growth and development of brain. In 2019, the iodine output of China is less than 1.0 kiloton, the iodine import amount is more than 6.6 kiloton, and the domestic iodine demand amount exceeds 7.4 kiloton, so that the iodine output of China can not meet the domestic market demand, and iodine is seriously imported. Iodine and its compounds are used in a wide variety of applications, for example, alcoholic solutions of iodine are commonly used as disinfectants; silver iodide can be used as a sensitizer and a seed crystal during artificial rainfall; iodoform can be used as preservative; iodine can be used as a tracer for geothermal system monitoring, and is also an important raw material for the production of iodine series medical contrast agents and various chemical pharmaceutical products.
In 2021, the yield of phosphate rock in China is 10289.9 ten thousand tons, the grade of symbiotic iodine is 15-40ppm, and the iodine content is about 2572.5 tons according to the average grade of 25ppm, so that the production cost is high and the average grade is limited due to the existing mastering technology, and most of iodine is lost from gas and liquid phases; iodine carried in iodine unit wastewater in industrial production is still 0.2-1% unrenewed, and most of the iodine is discharged into the nature through water bodies; the loss of iodine not only causes resource waste and long-term loss and enrichment, but also causes serious pollution to the environment. The recovery of the associated iodine in the natural mineral production process and the residual iodine resources in the production wastewater of iodine units is significant for relieving the iodine deficiency current situation of China, reducing iodine import and reducing the dependence of China on international iodine resources.
The existing iodine recovery process mainly comprises an air blowing method, an ion exchange method, an active carbon adsorption method, a liquid film separation method, a solvent flotation method, an electrochemical method and the like, and other processes are in a research stage and are not applied in large scale except that the air blowing method, the ion exchange method and the active carbon adsorption method are more applied.
Air blowing method: the iodine-containing waste liquid is acidified by hydrochloric acid, then is oxidized by introducing chlorine, simultaneously free iodine is blown out by blowing air, and after absorption by sulfur dioxide, iodine is released by introducing chlorine (US 4013780, US3346331, US6004465, CN101323434A, etc.).
Ion exchange method: adding acid into salt brine containing iodide, brine or soaking solution, acidifying, adding oxidant to oxidize iodine-containing raw material solution, and adsorbing iodine by ion exchange column; eluting with sulfite solution, and separating iodine with potassium chlorate; the other is eluting with sodium hydroxide solution to generate iodide, acidifying with sulfuric acid in a reactor to precipitate free iodine, separating, and refining to obtain iodine.
Activated carbon adsorption method: the method is adopted in the United states at the earliest time, and the available iodine solution can be obtained by firstly absorbing iodine by using active carbon under the acidic condition, then eluting by using sodium hydroxide solution and further acidifying.
Research and development on iodine recovery have proposed corresponding iodine recovery methods, such as:
the Chinese patent application No. 201610881847.4 discloses a method for recovering iodine from a sulfonic acid-containing waste liquid of an acetic acid plant, which comprises the following steps: firstly, loading iodine-containing waste liquid of an acetic acid plant into an oxidation reactor, starting a stirrer, controlling the rotating speed of the stirrer to be 30-40 rps/min, and simultaneously controlling the rotating speed to be 8-10: 1-2: ozone and hydrogen peroxide are slowly introduced in a volume ratio of 0.2, the reaction time is 30-60 min, the iodine-containing waste liquid changes color, and then the volume ratio is 1: adding a proper amount of benzene or toluene as an organic solvent in a proportion of 0.2-0.3, suspending the color-changing body on the liquid surface, separating the color-changing body suspended on the liquid surface into another reactor, and simultaneously mixing the components in a proportion of 1: adding ethyl acetate as an eluent in a volume ratio of 0.1-0.2; the liquid obtained after elution was taken up in 1L: adding sodium nitrite into the mixture in a volume ratio of 0.01-0.1 mg for reoxidation to obtain black liquid iodine.
Chinese patent application No. 201710401832.8 discloses a method for recovering crude iodine from zinc suboxide, which comprises the steps of: alkaline leaching, namely adding alkali to the secondary zinc oxide material for leaching, and separating liquid from solid to obtain iodine-containing alkaline leaching liquid and leaching slag; acidifying, namely adding sulfuric acid or hydrochloric acid into the alkaline leaching solution to acidify to obtain iodine-containing liquid; oxidizing and blowing out, adding an oxidant into the acidified iodine-containing liquid, and blowing air into the solution to oxidize iodine into iodine steam to escape and separate; trapping, namely trapping iodine vapor by using a reducing agent to obtain iodine-enriched liquid; and (3) crystallizing and separating, namely adding oxidant into the iodine-enriched liquid for crystallization to obtain black and purple solid crystals, and carrying out vacuum filtration and separation to obtain crude iodine.
The Chinese patent application No. 201810685070.3 discloses a method for recovering iodine from iodine-containing trimethylgallium waste liquid, which comprises the following steps: s1: the temperature of the iodine-containing trimethylgallium waste liquid is raised to 100-160 ℃, the organic solvent is completely distilled out and is connected to a collecting bottle through a connecting pipe, the collecting bottle collects the organic solvent, and the rest is first solution; s2: adding 30-36% of concentrated hydrochloric acid into the first solution, and heating to 40-50 ℃ to form a second solution; s3: adding sodium chlorate into the second solution to form a first mixed solution; filtering the first mixed solution to obtain crude iodine and a third solution; s4: sublimating the crude iodine to obtain refined iodine.
The Chinese patent application No. 202111023658. X discloses a recovery method for recycling solid iodine in iodine-containing wastewater by a steam iodine extraction method, which comprises the following specific steps: firstly, pretreatment and classification of wastewater containing iodine to be extracted; detecting iodine concentration and PH value of iodine-containing wastewater in an iodine-containing wastewater storage tank, classifying and storing, pumping wastewater with similar detection results and regularly generated back flushing water into a reaction precipitation tank, adding acid and alkali into the mixed solution to adjust PH, uniformly mixing, generating part of iodine gas and acid mist gas, and conveying the part of iodine gas and acid mist gas into an iodine gas absorption tower through a pipeline; (II) reacting to generate solid iodine; sampling the residual mixed solution, detecting the concentration of iodine, adding an antioxidant, a chelating agent and hydrogen peroxide, and reacting to generate iodine precipitation and iodine gas, wherein the iodine gas is conveyed into an iodine gas absorption tower through a pipeline; (III) centrifugal dehydration; detecting the reaction state of the solution, discharging the reactant from the reaction precipitation tank into a centrifugal dehydrator after the precipitation reaction is finished, and centrifugally dehydrating to obtain solid iodine; (IV) steam stripping iodine recycling; discharging filtrate discharged from the centrifugal dehydrator into a steam stripping iodine tank, performing constant temperature treatment on the filtrate to obtain iodine steam, and discharging the treated wastewater and waste gas; (V) iodine gas absorption; iodine vapor generated in the first step, the second step and the fourth step is independently conveyed into an iodine gas absorption tower through pipelines respectively, one part of the iodine vapor is concentrated by an iodine absorbent to become iodine absorption liquid, and the second step is repeated again; the other part of the generated acid mist enters an iodine gas absorption tower, is treated by an alkali spraying device and is discharged by an exhaust funnel.
Chinese patent application No. 201910363801.7 discloses a continuous method and continuous device for extracting iodide from iodine-containing wastewater. The continuous method comprises the following steps: continuously conveying the iodine-containing wastewater, acid and oxidant into a continuous reaction device for continuous reaction, wherein the continuous reaction device is filled with activated carbon; continuously conveying alkali liquor and eluent into a continuous reaction device for continuous desorption reaction to obtain desorption liquid containing iodide ions; extracting the desorption solution containing iodide ions to obtain iodide. The continuous process further comprises, prior to continuously delivering the iodine-containing wastewater, the acid, and the oxidizing agent to a continuous reaction apparatus: mixing the iodine-containing wastewater with the acid to obtain a first mixed solution; conveying the first mixed solution and the oxidant to the continuous reaction device respectively; preferably, the ratio of the iodine ions in the iodine-containing wastewater to the mole numbers of the acid and the oxidant is 1 (0.5-4): 0.25-0.5. The temperature of the continuous reaction is 0-120 ℃, and the reaction time is 10-120 min; preferably, the temperature of the continuous reaction is 10-30 ℃ and the reaction time is 20-60 min. The acid is selected from one or more of the group consisting of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, formic acid, acetic acid, p-toluenesulfonic acid and methanesulfonic acid; preferably, the iodine value of the activated carbon is more than or equal to 900mg/g, and the particle size is 2-5 mm. The oxidant is selected from hydrogen peroxide, ozone or oxygen; when the oxidant is hydrogen peroxide, the concentration of the hydrogen peroxide is 30wt%. The temperature of the continuous desorption reaction is 0-120 ℃, and the reaction time is 10-120 min; preferably, the temperature of the continuous desorption reaction is 0-30 ℃ and the reaction time is 20-60 min. The serialization method further comprises: continuously inputting a solvent into the continuous reaction device in the continuous reaction and/or continuous desorption reaction process; preferably, the solvent is selected from one or more of the group consisting of water, chloroform, dichloromethane, ethyl acetate, tetrahydrofuran, 2-methyltetrahydrofuran, 1, 4-dioxane, benzene, toluene and xylene. The continuous reaction device is selected from a continuous column reactor, a tubular reactor or a grid reactor. The extraction treatment method is selected from continuous concentration method, continuous crystallization method or continuous spray drying method. The eluent is selected from hydrazine hydrate and/or ammonia water; the alkali liquor is alkali aqueous solution, and alkali in the alkali aqueous solution is selected from one or more of sodium hydroxide, potassium hydroxide and lithium hydroxide. The method does not pretreat and filter impurities from the iodine-containing feed liquid, impurities in the feed liquid, alkali liquor and acid liquor in large-scale production enter a reactor, and sediment generated in a complex mixing process is easy to block active carbon pores, so that the adsorption rate of the active carbon to iodine is reduced; the process of frequently replacing the active carbon in the reactor can influence the production continuity, and the alkaline solution is used as the desorption liquid, so that the residual liquid is difficult to recycle and dispose after the iodine is extracted by acidification, and the method is not environment-friendly; the used activated carbon has unsafe hidden trouble and great supervision difficulty in the replacement, outward transportation and disposal processes of dangerous waste in the exposed environment of the site.
Therefore, at present, people have obtained a lot of results on research on iodine recovery, but in actual production, the iodine recovery method still has some defects, such as insufficient continuous production capacity, limited productivity, high energy consumption, high operation cost, limited grade of iodine-containing feed liquid, environment protection and potential safety hazard caused by device integration and insufficient sealing.
Disclosure of Invention
The invention aims to provide a method and a system for continuously recycling iodine from low-grade iodine-containing feed liquid. The method mainly comprises the steps of firstly, preprocessing and filtering iodine-containing feed liquid to remove impurities, then adding an oxidant in combination with the content of iodine ions in the feed liquid to adjust iodine ions into elemental iodine, and then, introducing the feed liquid subjected to preprocessing and iodine ion adjustment into an adsorption tower provided with a carrier, and adsorbing iodine by using the carrier in the tower; the iodine-containing feed liquid is guided to enter from the lower part and flow out from the upper part of the first adsorption tower connected in series through the pipeline, then enters from the lower part and flows out from the upper part of the next adsorption tower, and the turbulent flow effect formed by the liquid flow in the adsorption towers and the multiple adsorption capturing structure of the carriers in the adsorption towers connected in series are utilized to quickly finish the iodine adsorption, so that the adsorption rate and the efficiency of iodine are improved; when iodine adsorbed by the carrier in the adsorption tower is close to saturation, closing an incoming valve, evacuating residual feed liquid, and introducing an iodine remover to clean and regenerate the carrier in the adsorption tower for repeated use; iodine contained in the iodine remover for regenerating the carrier is oxidized, crystallized, precipitated, recovered and refined by the oxidant to obtain an iodine product; the iodine remover after iodine recovery is reused, so that the environment is protected; the carrier and the adsorption tower form a closed assembly structure, and the valves and flanges are arranged at two ends of the carrier and the adsorption tower, so that the valves at the two ends can be integrally disassembled, replaced and transported after being closed, and potential safety hazards caused by exposing and storing the carrier in an irregular field are avoided; the same parallel adsorption device is utilized, or an upper annular pipeline and a lower annular pipeline which are connected in parallel are added to a plurality of adsorption towers which are connected in series, the liquid flow direction is controlled through a valve, the front-back sequencing of the adsorption towers is changed, the adsorption towers are programmed into new adsorption sequencing or are withdrawn from adsorption work according to the production sequencing requirement, the partial adsorption towers are independently completed on the premise of ensuring that the device is not stopped, the work such as iodine adsorption, analysis, carrier regeneration, re-use and the like is ensured, and the device can be produced continuously.
In order to achieve the above purpose, the present invention adopts the following technical scheme:
a method for continuously recovering iodine from low-grade iodine-containing feed liquid comprises the following steps:
step one, preprocessing;
the components restricting iodine recovery in the iodine-containing feed liquid and harmful substances are combined for pretreatment and filtration, and the harmful substances are removed;
step two, pH adjustment;
the pH value of the pretreated iodine-containing feed liquid is adjusted to 1-4 by an acid/alkali medicament;
step three, regulating iodide ions;
adding an oxidant in combination with the content of iodide ions in the iodine-containing feed liquid with the adjusted pH value, and adjusting the iodide ions into elemental iodine;
step four, iodine adsorption;
the method comprises the steps of utilizing an adsorption tower and loose carriers arranged in the tower in series to adsorb iodine in iodine-containing feed liquid after iodine ion adjustment, adopting a mode of leading the iodine-containing feed liquid to enter from the lower part and flow out from the upper part of the adsorption tower and then entering from the lower part and flow out from the upper part of the next adsorption tower, and utilizing turbulence, the adsorption effect of different carriers on iodine and multiple enrichment capacity to improve the iodine adsorption rate;
step five, regenerating the carrier;
calculating the iodine adsorption amount and the analysis regeneration time of the carrier in the adsorption tower by using a flowmeter, the iodine content in the iodine-containing feed liquid before adsorption, the carrier loading amount in the adsorption tower, the adsorption rate of different mediums on iodine and the residual iodine content in the iodine-containing feed liquid after adsorption;
When iodine absorbed by the carrier approaches the analysis point, the valve is closed, so that the adsorption tower needing analysis and regeneration temporarily exits the adsorption work, then residual feed liquid is pumped back, then iodine eluent is introduced from the lower part and the upper part of the adsorption tower through the parallel pipeline and flows out, and the iodine eluent is circulated through the eluent groove, so that the carrier can finish the deiodination and regeneration in the adsorption tower;
the concentration of the iodine eluent is combined with the assay data and the regeneration requirement of the carrier in the adsorption tower is adjusted by dripping new eluent;
the carrier is cleaned and regenerated by the iodine eluent, then the residual iodine remover in the adsorption tower is refluxed to an eluent blending tank by a control valve, the carrier in the adsorption tower is cleaned by a cleaning agent or clear water through a parallel pipeline, the cleaning agent or clear water enters from the lower part of the adsorption tower, forms turbulent mixing with the carrier in the tower and then flows out from the upper part of the adsorption tower, and then forms a circulation with the clear water tank, thereby realizing automatic secondary cleaning; the adsorption tower and the carrier are reused after the carrier regeneration and cleaning;
step six, iodine recovery;
the iodine eluent containing iodine after the carrier regeneration is put into an iodine crystallization tank, crystallization precipitation of iodine is gradually realized by dropwise adding hydrogen peroxide for a plurality of times, stirring and standing, and the iodine eluent are separated by suction filtration, so that the iodine recovery is completed; the iodine eluent is recycled.
In the invention, a loose iodine adsorption carrier is arranged in the middle of an adsorption tower, a certain space is reserved, and filter screens are arranged at the two ends of the tower to prevent the carrier from losing; the adsorption towers are provided with the same or different adsorption carriers, and the adsorption carriers are combined with components to be adsorbed in the feed liquid for use; the feed liquid enters from the lower pipe orifice of the adsorption tower, the feed liquid which is continuously flushed into the tower from bottom to top and the carrier in the tower are rolled together to form turbulent flow and are fully mixed, wherein iodine contained in the feed liquid is quickly adsorbed by the carrier and then flows out from the upper pipe orifice of the tower, so that the flux is improved; in order to improve the adsorption rate of iodine, the adsorption towers are used in groups of more than 2, in parallel, in series, and the feed liquid enters from the lower part of the adsorption tower in the first series, is mixed with the adsorption carrier in the tower and flows out from the upper part, then enters from the lower part of the adsorption tower in the second series, is mixed with the adsorption carrier in the tower again and flows out from the upper part, and so on, so as to form multiple adsorption capturing capacity, the iodine in the feed liquid is adsorbed and depleted step by step and is reduced to a design interval; the serial number of the adsorption towers and the types of the carriers are set according to the requirements; in a grouping state of guaranteeing the adsorption rate, adding an adsorption tower to an adsorption tower group filled with different carriers respectively to serve as a standby rotation so as to replace when any one of the same adsorption towers in operation is out of adsorption order; when the combined adsorption of different carrier adsorption tower groups is adopted, the grouping of more than 2 adsorption towers is firstly carried out on the same carrier tower in series according to the method, and then the front and back series connection is carried out on the different carrier adsorption tower groups; when the adsorption carriers in the adsorption towers are different, the same carrier towers can be respectively connected in series for grouping according to the method, and then different carrier adsorption tower groups are connected in series front and back; the feed liquid with iodine components removed is conveyed to a storage tank or directly used for other production lines; when iodine absorbed by the carrier in the adsorption tower is close to saturation, the adsorption tower is withdrawn from the adsorption work, residual feed liquid is refluxed, the carrier in the adsorption tower is regenerated and cleaned by the iodine remover and the cleaning liquid respectively and then reused, and the final sequencing of the same adsorption carrier is woven when the adsorption tower is put into line. When the carrier is regenerated or the equipment is overhauled, the feed liquid is adjusted to the next sequencing adsorption tower through a bridge type pipeline, so that the uninterrupted operation of the device is ensured.
In the pretreatment of the invention, substances which remain in the iodine-containing feed liquid and affect the iodine adsorption of the process are dissolved, neutralized, coated or precipitated by adding the medicament. The solidified material is filtered and analyzed by assay, and the environment-friendly treatment is carried out by combining the attribute of the solidified material.
In the invention, a reflux device and a residue filtering device are arranged on iodine-containing feed liquid, iodine eluent, cleaning agent or clear water which are remained in the adsorption tower in the carrier regeneration process, so that the influence of residual liquid on the process is reduced; and after the filter residues are analyzed by an assay, the environment-friendly treatment is carried out on the combined components.
The invention further describes that the pretreatment in the first step is specifically as follows: firstly adding a pretreatment agent into the iodine-containing feed liquid, and filtering the iodine-containing feed liquid through a filter after full reaction; the filter is any one or a combination of a plurality of microporous filters, membrane filters, fibers and sponges;
the acid/alkali agent in the second step is any one or a combination of more than one of sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid and sodium hydroxide;
the oxidant in the third step is hydrogen peroxide or sodium nitrite;
the carrier in the adsorption tower in the fourth step is any one or a combination of more than one of active carbon, resin, carbon fiber and graphene;
In the fifth step, the analysis point is that the iodine adsorption amount is 4% of the weight of the carrier; the iodine eluent is sulfurous acid solution, sodium sulfite solution or sodium thiosulfate solution; the cleaning agent is sodium hydroxide solution.
In the first step, when the iodine-containing feed liquid contains refractory organic matters, antibiotics and pathogenic bacteria, the iodine-containing feed liquid is subjected to irradiation decomposition, degradation treatment and filtration by adopting electron beams generated by an electron accelerator, and then is subjected to pretreatment. The electron accelerator accelerates electrons to a high speed and has large energy, and ionizing radiation can be generated when the electrons are irradiated into water, so that a series of reactions are initiated, and the generated strong oxidizing substances are decomposed, interact with pollutants, bacteria and the like in the water to decompose and degrade the strong oxidizing substances, thereby improving the treatment efficiency of complex and difficult-to-degrade organic matters or hazardous matters and reducing the treatment cost; the electron accelerator used is free of nuclide and radiation, high in safety and capable of being stably controlled in a combined mode. The solidified material is filtered and analyzed by assay, and the environment-friendly treatment is carried out by combining the attribute of the solidified material.
The invention is further illustrated by the inclusion of pre-treatment agents including, but not limited to, various types of oxidants, acids, bases, salt modifiers, neutralising agents or adsorbents.
The invention further describes that the pH adjustment in the second step is specifically: carrying out assay analysis on the iodine-containing feed liquid from which the harmful substances are removed, dripping corresponding reagents into an acidic reagent tank, a neutral reagent tank or an alkaline reagent tank according to assay data, and adjusting the pH value of the feed liquid to a range of 1-4 so as to meet the later process requirements; filtering out precipitate from the iodine-containing feed liquid with the pH value adjusted through a filter, carrying out assay analysis on the precipitate, and carrying out environmental protection treatment by combining components; the iodine-containing feed liquid after removing the sediment enters an iodine ion adjusting tank.
The invention further describes that the iodine ion adjustment in the step three is specifically as follows: the iodine-containing feed liquid with the sediment removed is subjected to assay analysis in an iodine ion regulating tank, and an oxidant is dripped from an oxidant tank to enter the iodine ion regulating tank to convert iodine ions contained in the feed liquid, so that the iodine ions contained in the feed liquid are converted into elemental iodine, and the adsorption of a carrier is facilitated; the oxidant added is mainly hydrogen peroxide, and the addition amount is that the iodine ion rate in the feed liquid is reduced to below 5 percent of the content; according to different components in the feed liquid and combining process requirements, a small amount of other reagents can be added for component adjustment; the iodine-containing feed liquid regulated by iodine ions enters an iodine adsorption process.
In the fourth step, the adsorption towers are provided with more than two adsorption towers, and each adsorption tower can independently withdraw from the adsorption work without influencing the adsorption work of the other adsorption towers.
In the fourth step, more than two adsorption towers with the same carrier are arranged, the adsorption towers are used in parallel, in series and in groups, the adsorption rate is improved by utilizing the multiple adsorption capacity, and the upper limit of the number of the adsorption towers is flexibly set according to the requirement of the adsorption rate and economic indexes; the same adsorption towers are arranged in each group of adsorption towers to serve as replacement, so that when any one same adsorption tower exits the adsorption work, the adsorption towers are immediately put into the group for replacement; the bridge type pipeline and the valve are arranged on the upper part and the lower part of the adsorption tower group, so that the adsorption sequencing can be flexibly adjusted according to the grouping requirement among each adsorption tower; the adsorption towers are basically woven into the final adsorption sequence according to the first regeneration of the first application and the last application so as to ensure the adsorption efficiency of the adsorption tower group to iodine.
The adsorption tower can realize the work of withdrawing, regenerating and cleaning any one adsorption tower on line and putting into use again through bridge type pipeline control on the premise of not needing to be disassembled and assembled, and can automatically operate; the iodine-containing regenerated liquid after the regeneration of the adsorption tower carrier can also finish the oxidation crystallization of iodine and recover iodine products on site.
In the fifth step, the invention further illustrates that in the carrier regeneration process, a reflux device and a residue filtering device are arranged on the iodine-containing feed liquid, the iodine eluent, the cleaning agent or the clear water which are remained in the adsorption tower, so that the influence of residual liquid on the process is reduced; in the carrier regeneration process, a heating device and a thermocouple are arranged on a delivery pipeline of the iodine remover, the cleaning liquid or the clear water, the temperature can be automatically controlled, and after the requirements of the process on the ambient air temperature and the feed liquid temperature are set, the system can be automatically controlled in a reasonable interval.
The invention also provides a system for continuously recycling iodine from low-grade iodine-containing feed liquid, which comprises an iodine-containing feed liquid tank, a pretreatment tank, a filter I, a pH adjusting tank, a filter II, an iodine ion adjusting tank, a pump, a flowmeter, an adsorption tower group, a deiodination feed liquid storage tank, an iodine eluent preparing tank, an iodine eluent tank, a water tank, a cleaning agent tank, a crystallization tank and a suction filter; the iodine-containing material liquid tank, the pretreatment tank, the filter I, the pH adjusting tank, the filter II, the iodine ion adjusting tank, the pump, the flowmeter, the adsorption tower group and the deiodination material liquid storage tank are sequentially communicated; the adsorption tower group consists of more than two adsorption towers which are connected in series, a carrier for adsorbing iodine is arranged in each adsorption tower, a liquid inlet is arranged at the bottom of each adsorption tower, and a liquid outlet is arranged at the top of each adsorption tower; the flowmeter is communicated with the liquid inlet of each adsorption tower in the adsorption tower group, and each passage is provided with a valve and a flange; the liquid outlet of each adsorption tower in the adsorption tower group is communicated with the deiodination liquid storage tank, and each passage is provided with a valve and a flange; each passage is provided with a control valve, and each adsorption tower in the adsorption tower group can independently withdraw from adsorption work without affecting the adsorption work of other adsorption towers; the water pool is communicated with the liquid inlet of each adsorption tower in the adsorption tower group through a pump, and each passage is provided with a valve; the water pool is also communicated with the liquid outlet of each adsorption tower in the adsorption tower group, and each passage is provided with a valve; the iodine eluent mixing tank is communicated with the liquid inlet of each adsorption tower in the adsorption tower group through a pump, and each passage is provided with a valve; the iodine eluent mixing tank is also communicated with the liquid outlet of each adsorption tower in the adsorption tower group, and each passage is provided with a valve; the iodine eluent preparing groove is communicated with the crystallization groove, and valves are arranged on the passages; the liquid inlet of the suction filter is communicated with the crystallization tank, and the liquid outlet of the suction filter is communicated with the iodine eluent mixing tank.
The invention also provides an adsorption tower, which comprises a tower body; the bottom of the tower body is provided with a liquid inlet, the top of the tower body is provided with a liquid outlet, two filter screens are arranged in the tower body, and an adsorption carrier is loaded between the filter screens; the liquid inlet and the liquid outlet are also provided with valves and flanges; the valve and the flange at two ends of the tower body form a closed assembly structure for the adsorption tower and the adsorption carrier, so that the adsorption tower is integrally disassembled, replaced and transported after the valve is closed, and the carrier is prevented from being exposed in an irregular place to generate potential safety hazards and environmental protection hazards.
The invention also provides application of the adsorption tower, wherein the adsorption tower is applied to a continuous process for recovering iodine from low-grade iodine-containing feed liquid, and the adsorption tower is provided with more than two adsorption towers and is used in a parallel, serial and marshalling connection mode; the bridge type pipeline and the valve are arranged on the upper portion and the lower portion of the adsorption tower group, and the adsorption sequencing can be flexibly adjusted by combining grouping among the adsorption towers through controlling the valve.
The invention has the advantages and effects that:
1. the method can enable the device to continuously operate, has large processing capacity, low energy consumption and low operation cost; the device has high tightness, integration and strong automation degree, and ensures safer, environment-friendly and economical process.
2. The carrier and the adsorption tower form a closed assembly structure, and the two ends of the carrier are provided with the valves and the flanges, so that the carrier can be integrally disassembled, replaced and transported after the valves are closed, the potential safety hazard caused by the exposure of the carrier on an irregular site is avoided, and the carrier is safer.
3. The iodine-containing feed liquid is pretreated and filtered to remove impurities and precipitates, so that the problem that the adsorption efficiency of the carrier to iodine is restricted or the active carbon pores are blocked to shorten the service cycle is avoided.
4. The waste water containing complex organic matters, antibiotics and pathogenic bacteria is irradiated by electron beams, the difficult-to-decompose structure of the waste water is rapidly destroyed and is degraded, the treatment efficiency of the complex difficult-to-decompose organic matters is improved, and the treatment cost is reduced; the electron accelerator has no nuclide, no radiation, high safety and stable combined control.
5. When iodine adsorbed by the carrier in the adsorption tower is close to saturation, introducing an iodine remover for cleaning and regenerating for reuse; the iodine eluent is recycled, and is more environment-friendly.
6. Iodine in the pretreated iodine-containing feed liquid is concentrated in a targeted and high-efficiency manner by the carrier in the adsorption tower, and then iodine is recovered only by the concentrated carrier, so that the consumption of iodine recovery materials and the power cost are reduced, the method is more economical, and the grade limit of the iodine recovery feed liquid is widened.
7. When the carrier is regenerated or the equipment is overhauled, the feed liquid to be treated can be adjusted to the next sequencing adsorption tower through a bridge type pipeline, so that the uninterrupted operation of the device is ensured; therefore, the adsorption tower wheel can be replaced to finish the work of iodine adsorption, analysis, carrier regeneration, maintenance or replacement, doubling, and the like.
8. The iodine-containing feed liquid is pretreated, filtered to remove impurities and adjust the PH value, iodine ions in the feed liquid are adjusted to elemental iodine by dropwise adding oxidant for oxidation, and then the capture capacity of turbulent mixing and multiple adsorption carriers formed by the serial adsorption towers and the iodine adsorption carriers and liquid flow in the towers is utilized, so that the iodine recovery rate and efficiency are improved; when iodine adsorption carriers in the adsorption towers are different, after serial grouping is respectively carried out according to the method, serial grouping is respectively carried out before and after the serial grouping is respectively carried out, so that the process is not damaged when part of the adsorption towers exit the adsorption sequencing.
9. In the carrier regeneration process, a reflux device and a residue filtering device are arranged on the iodine-containing feed liquid, iodine eluent, cleaning agent or clear water which are remained in the adsorption tower, so that the influence of residual liquid on the process can be reduced as much as possible.
10. The device in the method can realize unattended and large-flux production through an automatic system.
11. The device adsorbs the carrier to enrich the iodine in the feed liquid, and then recovers and refines the iodine aiming at the enriched carrier, thereby reducing the consumption of materials, power, manpower and the like, reducing the restriction conditions of capacity requirement, comprehensive cost, iodine-containing feed liquid grade and the like, and having stronger recycling capability.
Drawings
FIG. 1 is a schematic process flow diagram of an embodiment of the present invention.
Fig. 2 is a schematic diagram of an iodine recovery process path according to an embodiment of the present invention.
Detailed Description
Example 1:
a method for continuously recovering iodine from low-grade iodine-containing feed liquid, as shown in figure 1, comprising the following steps:
step one, preprocessing;
the components restricting iodine recovery in the iodine-containing feed liquid and harmful substances are combined for pretreatment and filtration, and the harmful substances are removed;
step two, pH adjustment;
the pH value of the pretreated iodine-containing feed liquid is adjusted to 1-4 by an acid/alkali medicament;
step three, regulating iodide ions;
adding an oxidant in combination with the content of iodide ions in the iodine-containing feed liquid with the adjusted pH value, and adjusting the iodide ions into elemental iodine;
step four, iodine adsorption;
the method comprises the steps of utilizing an adsorption tower and loose carriers arranged in the tower in series to adsorb iodine in iodine-containing feed liquid after iodine ion adjustment, adopting a mode of leading the iodine-containing feed liquid to enter from the lower part and flow out from the upper part of the adsorption tower and then entering from the lower part and flow out from the upper part of the next adsorption tower, and utilizing turbulence, the adsorption effect of different carriers on iodine and multiple enrichment capacity to improve the iodine adsorption rate;
Step five, regenerating the carrier;
calculating the iodine adsorption amount and the analysis regeneration time of the carrier in the adsorption tower by using a flowmeter, the iodine content in the iodine-containing feed liquid before adsorption, the carrier loading amount in the adsorption tower, the adsorption rate of different mediums on iodine and the residual iodine content in the iodine-containing feed liquid after adsorption;
when iodine absorbed by the carrier approaches the analysis point, the valve is closed, so that the adsorption tower needing analysis and regeneration temporarily exits the adsorption work, then residual feed liquid is pumped back, then iodine eluent is introduced from the lower part and the upper part of the adsorption tower through the parallel pipeline and flows out, and the iodine eluent is circulated through the eluent groove, so that the carrier can finish the deiodination and regeneration in the adsorption tower;
the concentration of the iodine eluent is combined with the assay data and the regeneration requirement of the carrier in the adsorption tower is adjusted by dripping new eluent;
the carrier is cleaned and regenerated by the iodine eluent, then the residual iodine remover in the adsorption tower is refluxed to an eluent blending tank by a control valve, the carrier in the adsorption tower is cleaned by a cleaning agent or clear water through a parallel pipeline, the cleaning agent or clear water enters from the lower part of the adsorption tower, forms turbulent mixing with the carrier in the tower and then flows out from the upper part of the adsorption tower, and then forms a circulation with the clear water tank, thereby realizing automatic secondary cleaning; the adsorption tower and the carrier are reused after the carrier regeneration and cleaning;
Step six, iodine recovery;
the iodine eluent containing iodine after the carrier regeneration is put into an iodine crystallization tank, crystallization precipitation of iodine is gradually realized by dropwise adding hydrogen peroxide for a plurality of times, stirring and standing, and the iodine eluent are separated by suction filtration, so that the iodine recovery is completed; the iodine eluent is recycled.
Example 2:
a method for continuously recovering iodine from low-grade iodine-containing feed liquid comprises the following steps:
step one, preprocessing;
the components restricting iodine recovery in the iodine-containing feed liquid and harmful substances are combined for pretreatment and filtration, and the harmful substances are removed; the method comprises the following steps: firstly adding a pretreatment agent into the iodine-containing feed liquid, and filtering the iodine-containing feed liquid through a filter after full reaction; the filter is any one or a combination of a plurality of microporous filters, membrane filters, fibers and sponges; the pretreatment agent includes, but is not limited to, various oxidizing agents, acids, bases, salt modifiers, neutralizing agents, or adsorbents;
step two, pH adjustment;
the pH value of the pretreated iodine-containing feed liquid is adjusted to 1-4 by an acid/alkali medicament; the acid/alkali agent is any one or a combination of more of sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid and sodium hydroxide;
Step three, regulating iodide ions;
adding an oxidant in combination with the content of iodide ions in the iodine-containing feed liquid with the adjusted pH value, and adjusting the iodide ions into elemental iodine; the oxidant is hydrogen peroxide or sodium nitrite;
step four, iodine adsorption;
the method comprises the steps of utilizing an adsorption tower and loose carriers arranged in the tower in series to adsorb iodine in iodine-containing feed liquid after iodine ion adjustment, adopting a mode of leading the iodine-containing feed liquid to enter from the lower part and flow out from the upper part of the adsorption tower and then entering from the lower part and flow out from the upper part of the next adsorption tower, and utilizing turbulence, the adsorption effect of different carriers on iodine and multiple enrichment capacity to improve the iodine adsorption rate;
the carrier in the adsorption tower is any one or a combination of more of active carbon, resin, carbon fiber and graphene;
step five, regenerating the carrier;
calculating the iodine adsorption amount and the analysis regeneration time of the carrier in the adsorption tower by using a flowmeter, the iodine content in the iodine-containing feed liquid before adsorption, the carrier loading amount in the adsorption tower, the adsorption rate of different mediums on iodine and the residual iodine content in the iodine-containing feed liquid after adsorption;
when iodine absorbed by the carrier approaches the analysis point, the valve is closed, so that the adsorption tower needing analysis and regeneration temporarily exits the adsorption work, then residual feed liquid is pumped back, then iodine eluent is introduced from the lower part and the upper part of the adsorption tower through the parallel pipeline and flows out, and the iodine eluent is circulated through the eluent groove, so that the carrier can finish the deiodination and regeneration in the adsorption tower;
The concentration of the iodine eluent is combined with the assay data and the regeneration requirement of the carrier in the adsorption tower is adjusted by dripping new eluent;
the carrier is cleaned and regenerated by the iodine eluent, then the residual iodine remover in the adsorption tower is refluxed to an eluent blending tank by a control valve, the carrier in the adsorption tower is cleaned by a cleaning agent or clear water through a parallel pipeline, the cleaning agent or clear water enters from the lower part of the adsorption tower, forms turbulent mixing with the carrier in the tower and then flows out from the upper part of the adsorption tower, and then forms a circulation with the clear water tank, thereby realizing automatic secondary cleaning; the adsorption tower and the carrier are reused after the carrier regeneration and cleaning;
the analysis point is that the iodine adsorption amount is 4% of the weight of the carrier; the iodine eluent is sulfurous acid solution, sodium sulfite solution or sodium thiosulfate solution; the cleaning agent is sodium hydroxide solution;
step six, iodine recovery;
the iodine eluent containing iodine after the carrier regeneration is put into an iodine crystallization tank, crystallization precipitation of iodine is gradually realized by dropwise adding hydrogen peroxide for a plurality of times, stirring and standing, and the iodine eluent are separated by suction filtration, so that the iodine recovery is completed; the iodine eluent is recycled.
Example 3:
A method for continuously recovering iodine from low-grade iodine-containing feed liquid comprises the following steps:
step one, preprocessing;
the components restricting iodine recovery in the iodine-containing feed liquid and harmful substances are combined for pretreatment and filtration, and the harmful substances are removed; the method comprises the following steps: firstly adding a pretreatment agent into the iodine-containing feed liquid, and filtering the iodine-containing feed liquid through a filter after full reaction; the filter is any one or a combination of a plurality of microporous filters, membrane filters, fibers and sponges; the pretreatment agent includes, but is not limited to, various oxidizing agents, acids, bases, salt modifiers, neutralizing agents, or adsorbents;
step two, pH adjustment;
the pH value of the pretreated iodine-containing feed liquid is adjusted to 1-4 by an acid/alkali medicament; the method comprises the following steps: carrying out assay analysis on the iodine-containing feed liquid from which the harmful substances are removed, dripping corresponding reagents into an acidic reagent tank, a neutral reagent tank or an alkaline reagent tank according to assay data, and adjusting the pH value of the feed liquid to a range of 1-4 so as to meet the later process requirements; filtering out precipitate from the iodine-containing feed liquid with the pH value adjusted through a filter, carrying out assay analysis on the precipitate, and carrying out environmental protection treatment by combining components; the iodine-containing feed liquid after removing the sediment enters an iodine ion adjusting tank; the acid/alkali agent is any one or a combination of more of sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid and sodium hydroxide;
Step three, regulating iodide ions;
adding an oxidant in combination with the content of iodide ions in the iodine-containing feed liquid with the adjusted pH value, and adjusting the iodide ions into elemental iodine; the method comprises the following steps: the iodine-containing feed liquid with the sediment removed is subjected to assay analysis in an iodine ion regulating tank, and an oxidant is dripped from an oxidant tank to enter the iodine ion regulating tank to convert iodine ions contained in the feed liquid, so that the iodine ions contained in the feed liquid are converted into elemental iodine, and the adsorption of a carrier is facilitated; the oxidant added is mainly hydrogen peroxide, and the addition amount is that the iodine ion rate in the feed liquid is reduced to below 5 percent of the content; according to different components in the feed liquid and combining process requirements, a small amount of other reagents can be added for component adjustment; the iodine-containing feed liquid regulated by iodine ions enters an iodine adsorption process;
step four, iodine adsorption;
the method comprises the steps of utilizing an adsorption tower and loose carriers arranged in the tower in series to adsorb iodine in iodine-containing feed liquid after iodine ion adjustment, adopting a mode of leading the iodine-containing feed liquid to enter from the lower part and flow out from the upper part of the adsorption tower and then entering from the lower part and flow out from the upper part of the next adsorption tower, and utilizing turbulence, the adsorption effect of different carriers on iodine and multiple enrichment capacity to improve the iodine adsorption rate;
The carrier in the adsorption tower is any one or a combination of more of active carbon, resin, carbon fiber and graphene;
step five, regenerating the carrier;
calculating the iodine adsorption amount and the analysis regeneration time of the carrier in the adsorption tower by using a flowmeter, the iodine content in the iodine-containing feed liquid before adsorption, the carrier loading amount in the adsorption tower, the adsorption rate of different mediums on iodine and the residual iodine content in the iodine-containing feed liquid after adsorption;
when iodine absorbed by the carrier approaches the analysis point, the valve is closed, so that the adsorption tower needing analysis and regeneration temporarily exits the adsorption work, then residual feed liquid is pumped back, then iodine eluent is introduced from the lower part and the upper part of the adsorption tower through the parallel pipeline and flows out, and the iodine eluent is circulated through the eluent groove, so that the carrier can finish the deiodination and regeneration in the adsorption tower;
the concentration of the iodine eluent is combined with the assay data and the regeneration requirement of the carrier in the adsorption tower is adjusted by dripping new eluent;
the carrier is cleaned and regenerated by the iodine eluent, then the residual iodine remover in the adsorption tower is refluxed to an eluent blending tank by a control valve, the carrier in the adsorption tower is cleaned by a cleaning agent or clear water through a parallel pipeline, the cleaning agent or clear water enters from the lower part of the adsorption tower, forms turbulent mixing with the carrier in the tower and then flows out from the upper part of the adsorption tower, and then forms a circulation with the clear water tank, thereby realizing automatic secondary cleaning; the adsorption tower and the carrier are reused after the carrier regeneration and cleaning;
The analysis point is that the iodine adsorption amount is 4% of the weight of the carrier; the iodine eluent is sulfurous acid solution, sodium sulfite solution or sodium thiosulfate solution; the cleaning agent is sodium hydroxide solution;
step six, iodine recovery;
the iodine eluent containing iodine after the carrier regeneration is put into an iodine crystallization tank, crystallization precipitation of iodine is gradually realized by dropwise adding hydrogen peroxide for a plurality of times, stirring and standing, and the iodine eluent are separated by suction filtration, so that the iodine recovery is completed; the iodine eluent is recycled.
Example 4:
this embodiment differs from embodiment 3 in that: in the first step, when the iodine-containing feed liquid contains refractory organic matters, antibiotics and pathogenic bacteria, the iodine-containing feed liquid is subjected to irradiation decomposition, degradation treatment and filtration by adopting electron beams generated by an electron accelerator, and then is subjected to pretreatment.
The system used in the above embodiment comprises an iodine-containing liquid tank 1, a pretreatment tank 7, a filter I9, a pH adjusting tank 10, a filter II 14, an iodine ion adjusting tank 15, a pump 17, a flowmeter 18, an adsorption tower group, a deiodination liquid storage tank 53, an iodine eluent preparing tank 67, an iodine eluent tank 70, a water tank 61, a cleaning agent tank 59, a crystallization tank 75 and a suction filter 76;
The iodine-containing liquid tank 1, the pretreatment tank 7, the filter I9, the pH adjusting tank 10, the filter II 14, the iodine ion adjusting tank 15, the pump 17, the flowmeter 18, the adsorption tower group and the deiodination liquid storage tank 53 are sequentially communicated;
the adsorption tower group consists of more than two adsorption towers which are connected in series, a carrier for adsorbing iodine is arranged in each adsorption tower, a liquid inlet is arranged at the bottom of each adsorption tower, and a liquid outlet is arranged at the top of each adsorption tower;
the flow meter 18 is communicated with the liquid inlet of each adsorption tower in the adsorption tower group, and each passage is provided with a valve and a flange; the liquid outlet of each adsorption tower in the adsorption tower group is communicated with the deiodination liquid storage tank 18, and each passage is provided with a valve and a flange; each passage is provided with a control valve, and each adsorption tower in the adsorption tower group can independently withdraw from adsorption work without affecting the adsorption work of other adsorption towers;
the water tank 61 is communicated with the liquid inlet of each adsorption tower in the adsorption tower group through a pump, and each passage is provided with a valve; the water tank 61 is also communicated with the liquid outlet of each adsorption tower in the adsorption tower group, and each passage is provided with a valve;
The iodine eluent mixing groove 67 is communicated with the liquid inlet of each adsorption tower in the adsorption tower group through a pump, and each passage is provided with a valve; the iodine eluent mixing groove 67 is also communicated with the liquid outlet of each adsorption tower in the adsorption tower group, and each passage is provided with a valve;
the iodine eluent preparing groove 67 is communicated with the crystallizing groove 75, and valves are arranged on the passages;
the liquid inlet of the suction filter 76 is communicated with the crystallization tank 75, and the liquid outlet of the suction filter 76 is communicated with the iodine eluent mixing tank 67.
Example 5:
an adsorption tower comprises a tower body; the bottom of the tower body is provided with a liquid inlet, the top of the tower body is provided with a liquid outlet, two filter screens are arranged in the tower body, and an adsorption carrier is loaded between the filter screens; the liquid inlet and the liquid outlet are also provided with valves and flanges; the valve and the flange at two ends of the tower body form a closed assembly structure for the adsorption tower and the adsorption carrier, so that the adsorption tower is integrally disassembled, replaced and transported after the valve is closed, and the carrier is prevented from being exposed in an irregular place to generate potential safety hazards and environmental protection hazards.
The adsorption tower of the embodiment 5 is applied to a continuous process for recovering iodine from low-grade iodine-containing feed liquid, and the adsorption tower is provided with more than two adsorption towers and is used in a parallel, serial and marshalling connection mode; the bridge type pipeline and the valve are arranged on the upper portion and the lower portion of the adsorption tower group, and the adsorption sequencing can be flexibly adjusted by combining grouping among the adsorption towers through controlling the valve.
In order to make the present invention more clearly understood by those skilled in the art, the above embodiments may be implemented smoothly, and the specific flow paths of the various stages involved in the process of the present invention will be described in further detail with reference to the accompanying drawings.
As shown in fig. 2:
1. pretreatment of
The iodine and harmful substances in the iodine-containing material liquid tank 1 are subjected to assay analysis, the harmful substances and pretreatment requirements are combined to treat complex organic matters, antibiotics, pathogenic bacteria and the like in the iodine-containing material liquid tank through the electron accelerator 3 and the electron irradiation reactor 2 respectively, electrons are accelerated to a high speed and have high energy, ionizing radiation can be generated after being irradiated into water, a series of reactions are initiated, strong oxidizing substances generated through decomposition interact with pollutants, bacteria and the like in the water, the purposes of oxidative decomposition and disinfection are achieved, the iodine-containing material liquid tank is further treated through the biochemical device 5, and corresponding medicaments are added from the medicament tank 4 into the biochemical treatment device 5 according to the requirements; the feed liquid after biochemical treatment enters a pretreatment tank 7 after filter mud is removed by a filter 6; the filter mud is subjected to assay analysis and environmental protection treatment by combining properties; if the feed liquid in the iodine-containing feed liquid tank 1 is tested, no complex excessive organic matters, antibiotics, pathogenic bacteria and the like exist, and the feed liquid can directly enter the pretreatment tank 7;
The feed liquid in the pretreatment tank 7 is analyzed by assay, and the binding component is added dropwise with a pretreatment agent from the reagent tank 8 into the pretreatment tank 7 to dissolve, neutralize, wrap and precipitate the residual harmful substances, wherein the pretreatment agent comprises various oxidants, acids, alkalis, salt regulators, neutralizers or adsorbents; the precipitate is removed by a filter I9; the filtered filter mud is subjected to assay analysis and environmental protection treatment by combining the attribute of the filter mud; the iodine-containing feed liquid with the harmful substances filtered out enters a pH adjusting tank 10.
2. PH adjustment
Carrying out assay analysis on the iodine-containing feed liquid with harmful substances removed in the pH adjusting tank 10, dripping corresponding reagents into the acidic reagent tank 11, the neutral reagent tank 12 or the alkaline reagent tank 13 according to assay data, and adjusting the pH value of the feed liquid to 1-4 so as to meet the later process requirements; filtering out precipitate from the iodine-containing feed liquid with the adjusted pH value through a filter II 14, carrying out assay analysis on the precipitate, and carrying out environmental protection treatment by combining components; the iodine-containing feed solution from which the precipitate is removed is fed into an iodine ion adjusting tank 15.
3. Iodide ion modulation
The iodine-containing feed liquid with the sediment removed is subjected to assay analysis in an iodine ion adjusting tank 15, and an oxidant is dripped from an oxidant tank 16 to enter the iodine ion adjusting tank 15 to convert iodine ions contained in the feed liquid, so that the iodine ions contained in the feed liquid are converted into elemental iodine, and the adsorption of a carrier is facilitated; the oxidant added is mainly hydrogen peroxide, and the addition amount is that the iodine ion rate in the feed liquid is reduced to below 5 percent of the content; and a small amount of other reagents can be added for component adjustment according to different components in the feed liquid and combining process requirements. The iodine-containing feed liquid regulated by iodine ions enters an iodine adsorption process.
4. Iodine adsorption
The iodine-containing liquid which reaches the index through the adjustment of the oxidant in the iodine ion adjusting tank 15 is delivered by a pump 17 and metered by a flowmeter 18. Closing valve 20, valve 22, valve 29, valve 30, valve 31, valve 38, valve 39, valve 40, valve 46, valve 47, valve 48, valve 49, valve 50 and valve 51, opening valve 19, valve 21, valve 24, valve 26, valve 28, valve 33, valve 35, valve 37, valve 42, valve 44 and valve 52, and allowing iodine-containing feed liquid to be subjected to iodine adsorption by pump 17, flowmeter 18, valve 19, valve 21, valve 24, adsorption tower 25, valve 26, valve 28, valve 33, adsorption tower 34, valve 35, valve 37, valve 42 and adsorption tower 43; the two ends of the adsorption tower are provided with the filter screens, so that the loss of the carrier is prevented, the middle is provided with a loose carrier, a certain space is reserved, the carrier floats and rolls in the adsorption tower under the action of liquid flow from bottom to top, and the adsorption contact surface, the homogenization and the efficiency of iodine are improved; the iodine adsorption carrier in the adsorption tower can be combined with the adsorption characteristics of iodine and accompanying substances in the feed liquid, and is mainly one or a combination of more of active carbon, resin, carbon fiber, graphene and the like; iodine in the iodine-containing feed liquid is adsorbed by carriers in the multiple adsorption towers, the iodine content is depleted step by step, and the number of the serial adsorption towers can be set by combining the step-by-step depletion degree of the iodine content in the feed liquid and the running economy of the device; the material liquid with iodine adsorption is fed into deiodinated material liquid tank 53 via valve 44 and valve 52 for standby or is fed to other production lines via valve 54.
According to the analysis of the iodine content of the feed liquid in the iodine ion regulating tank 15, the flux of the flowmeter 18 and the iodine residual rate of the iodine-removing feed liquid discharged from the pipe orifice of the deiodination feed liquid tank 53, the quantity of the adsorption carriers in the adsorption towers 25, 34 and 43 and the adsorption rate of the carriers to iodine, the adsorption saturation of the iodine of the adsorption carriers in the adsorption towers 25, 34 and 43 is calculated, and when the iodine adsorption saturation reaches a reasonable economic concentration, the carrier regeneration work is started.
5. Carrier regeneration
The regeneration of the carrier is carried out in principle in a sequential order and is recycled. Firstly, the iodine-containing feed liquid is subjected to regeneration of carriers in the adsorption tower with the first order, and after the regeneration is finished, the carriers are arranged in the last adsorption order of the group for use. Before the carrier is regenerated, the adsorption tower to be regenerated is withdrawn from the adsorption work by opening and closing the relevant valve; then, according to the second adsorption sequence, the third adsorption sequence is arranged at the front, and so on, grouping and continuous operation are carried out; after the regeneration of the carrier in the first sequencing adsorption tower is finished, the carrier is integrated into the final adsorption sequencing; when the adsorption tower needing to regenerate the adsorption carrier stops running, the valves at the two ends are closed, and liquid flow is led into the next adsorption sequencing tower through the bridge type pipeline, so that the continuous production of the device is ensured. In the following, the working flows of 3 adsorption towers (tower 25, tower 34, tower 43 are exemplified to describe the operation of respectively withdrawing from adsorption, regenerating the carriers in the adsorption towers on line, re-entering the grouping and sequencing after regenerating the carriers in the adsorption towers, etc. the method can also be used for grouping more than 3 adsorption towers in series according to the same principle by combining the requirements and the operation economy.
1. Regeneration of the carrier in the adsorption tower 25:
in order to regenerate the carrier in the adsorption tower 25, the adsorption tower is controlled by a valve to withdraw from adsorption operation, iodine-containing feed liquid can be sequentially adjusted to form a new duplex grouping by taking the adsorption tower 34 as a first order and the adsorption tower 43 as a second order through opening and closing the valve, so that continuous operation of production is maintained, and meanwhile, the regeneration, dismantling, replacement or maintenance of the carrier in the adsorption tower 25 is performed on line; after the regeneration of the carrier in the adsorption tower 25 is completed, the carrier is re-programmed into a third order for use. The method comprises the following steps: the adsorption tower 25 is first withdrawn from the adsorption operation. Valve 20, valve 21, valve 29, valve 31, valve 38, valve 39, valve 40, valve 46, valve 48, valve 49, valve 50 and valve 51 are closed, valve 30, valve 33, valve 35, valve 37, valve 42, valve 44 and valve 52 are opened, iodine-containing feed liquid enters the deiodination feed liquid tank 53 through the pump 17, the flow meter 18, the valve 19, the valve 30, the valve 33, the adsorption tower 34, the valve 35, the valve 37, the valve 42, the adsorption tower 43, the valve 44 and the valve 52 and can enter other production lines through the valve 54 for use; at this time, the adsorption tower 25 successfully exits the adsorption operation;
the iodine-containing feed liquid remaining in the reflux adsorption column 25. Closing the valves 57, 62, 68 and 72, opening the valves 79, 47, 26, 24, 22 and 55, starting the pumps 56 and the filters 80, and enabling the residual iodine-containing feed liquid in the adsorption tower 25 to flow back to the iodine ion adjusting tank 15 through the valves 24, 22, 55, 56 and the filters 80; the upper port of the adsorption tower is communicated with a pipe orifice erected on the water tank 61 through a valve 26, a valve 47, a valve 79 and a pipeline, so as to ensure the balance of the air pressure in the tower when the pump 56 is started to reflux the feed liquid in the adsorption tower 25; the sludge generated in the filter 80 is environmentally treated according to the assay analysis properties.
And regenerating and cleaning the carrier in the adsorption tower 25 on line. Firstly, iodine eluent is adopted to carry out deiodination regeneration on carriers in an adsorption tower 25, valve 20, valve 21, valve 29, valve 31, valve 38, valve 39, valve 40, valve 46, valve 28, valve 48, valve 49, valve 50, valve 51, valve 79, valve 68, valve 55, valve 57 and valve 65 are checked and closed, valve 66, valve 62, valve 22, valve 24, valve 26, valve 47 and valve 72 are opened, a pump 64 is started, a heater 63 is started according to the temperature requirement, so that the iodine remover prepared in an iodine eluent preparation tank 67 flows back to the iodine eluent preparation tank 67 through valve 66, pump 64, heater 63, valve 62, valve 22, valve 24, adsorption tower 25, valve 26, valve 47 and valve 72; when the activity of the eluent in the iodine eluent preparing tank 67 is reduced, a valve 71 is opened, new iodine eluent is dripped from an eluent tank 70 into the tank 67, and the circulating liquid flow of the reflux is utilized for homogenization; when the iodine-containing grade of the iodine eluent in the iodine eluent preparing tank 67 is close to the iodine-containing grade difference of the iodine eluent entering the iodine eluent preparing tank 67 from the valve 72, stopping the cyclic regeneration of the iodine eluent on the adsorption tower 25; refluxing the iodine eluent, closing pump 64, heater 63, valve 62; opening the valve 68, starting the pump 69, and refluxing the iodine eluent remained in the adsorption tower 25 to the iodine eluent preparing tank 67 through the valve 24, the valve 22, the valve 68 and the pump 69; cleaning agent or clean water cleans the carrier in the adsorption tower 25, the pump 69 and the valves 68 and 72 are closed, the valves 65 and 62, the valves 22 and 24 are opened, the valves 26 and 47 are opened, the valves 79 and the pump 64 are started, and the heater 63 is opened according to the requirements, so that the clean water in the water tank 61 is returned to the water tank 61 through the valves 65 and 64, the heater 63, the valves 62 and 22, the valves 24 and 25, the valves 26 and 47 and the valves 79 to form circulation, and a certain amount of cleaning agent can be added from the cleaning agent tank 59 to the water tank 61 according to the cleaning requirements by opening the valves 60 so as to improve the cleaning effect on the carrier in the adsorption tower 25; after the cleaning agent enters the water tank 61, the cleaning agent is homogenized by circulation of liquid flow; after the cleaning, the clean water or the cleaning agent remaining in the adsorption tower 25 is refluxed, the heater 63, the pump 64 and the valve 62 are turned off, the valve 57 is turned on, the pump 58 is turned on, the cleaning agent remaining in the adsorption tower 25 is refluxed to the water tank 61 through the valve 24, the valve 22, the valve 57 and the pump 58, and the valves and the equipment are turned off after the reflux is completed.
The adsorption tower 25 is removed and replaced. Checking and closing the valve 20, the valve 21, the valve 22, the valve 24, the valve 26, the valve 47, the valve 48 and the valve 28, removing bolts or bayonets on the flange valve 27 and the flange 23, removing the whole adsorption tower 25, the valve 26 and the valve 24, and forming a closed assembly space by the carrier in the adsorption tower 25, the tower body, the valve 26 and the valve 24 under the closing state of the valve 26 and the valve 24, thereby realizing full-closed management.
The adsorption tower 25 is programmed into the final sequence when it is put back into service. After the adsorption tower 25 is regenerated, cleaned or replaced, the final adsorption sequencing is incorporated, the three-tower combined serial structure is that the adsorption tower 34 is in a first sequencing, the adsorption tower 43 is in a second sequencing, the adsorption tower 25 is in a third sequencing, and the adsorption tower 25 is incorporated into the third sequencing to operate as follows: valve 21, valve 22, valve 29, valve 31, valve 38, valve 39, valve 40, valve 28, valve 47, valve 49, valve 50, valve 51 and valve 52 are closed, valve 30, valve 33, valve 35, valve 37, valve 42, valve 44, valve 46, valve 20, valve 24, valve 26 and valve 48 are opened, so that iodine-containing feed liquid enters the iodine-containing feed liquid tank 53 through the pump 17, the flow meter 18, the valve 19, the valve 30, the valve 33, the adsorption tower 34, the valve 35, the valve 37, the valve 42, the adsorption tower 43, the valve 44, the valve 46, the valve 20, the valve 24, the adsorption tower 25, the valve 26 and the valve 48 to form a sequential adsorption sequencing combination of the iodine-containing feed liquid from the adsorption tower 34 to the adsorption tower 43 to the adsorption tower 25.
2. Regeneration of the carrier in the adsorption column 34:
in order to regenerate the carrier in the adsorption tower 34, the adsorption tower is controlled by a valve to withdraw from adsorption operation, iodine-containing feed liquid can be sequentially adjusted to form a new duplex group by taking the adsorption tower 43 as a first order and the adsorption tower 25 as a second order through opening and closing the valve, so that continuous operation of production is maintained, and meanwhile, the regeneration, dismantling, replacement or overhaul of the carrier in the adsorption tower 34 is carried out on line; after the regeneration of the carrier in the adsorption tower 34 is completed, the carrier is re-programmed into a third sequence for use. The method comprises the following steps: adsorption column 34 is first withdrawn from adsorption operation. Closing valves 21, 22, 29, 30, 38, 40, 28, 37, 47, 50, 51 and 52, opening valves 39, 42, 44, 46, 20, 24, 26 and 48, allowing iodine-containing feed liquid to enter a deiodinated feed liquid tank 53 through a pump 17, a flowmeter 18, 19, 39, 42, an adsorption tower (43, 44, 46, 20, 24, 25, 26 and 48) and allowing iodine-containing feed liquid to enter other production lines through a valve 54, wherein the adsorption tower 34 is successfully withdrawn from adsorption;
the iodine-containing feed liquid remaining in the reflux adsorption column 34. Closing the valves 57, 62, 68 and 72, opening the valves 79, 49, 35, 33, 31 and 55, starting the pumps 56 and the filters 80, and enabling the residual iodine-containing feed liquid in the adsorption tower 34 to flow back to the iodine ion adjusting tank 15 through the valves 33, 31, 55, 56 and the filters 80; the upper port of the adsorption tower is communicated with the pipe orifice on the water tank 61 through a valve 35, a valve 49, a valve 79 and a pipeline to ensure the balance of the air pressure in the tower when the pump 56 is started to reflux the feed liquid in the adsorption tower 34; the sludge generated in the filter 80 is environmentally treated according to the assay analysis properties.
The carrier in the adsorption tower 34 is regenerated and cleaned on line. Firstly, carrying out deiodination regeneration on a carrier in an adsorption tower 34 by adopting an iodine eluent, checking and closing a valve 21, a valve 22, a valve 29, a valve 30, a valve 38, a valve 40, a valve 28, a valve 37, a valve 47, a valve 50, a valve 51, a valve 52, a valve 55, a valve 57, a valve 65, a valve 68 and a valve 79, opening a valve 66, a valve 62, a valve 31, a valve 33, a valve 35, a valve 49 and a valve 72, starting a pump 64, and starting a heater 63 according to the temperature requirement, so that the iodine remover prepared in an iodine eluent preparation tank 67 flows back to the iodine eluent preparation tank 67 through the valve 66, the pump 64, the heater 63, the valve 62, the valve 31, the valve 33, the adsorption tower 34, the valve 35, the valve 49 and the valve 72; when the activity of the eluent in the iodine eluent preparing tank 67 is reduced, a valve 71 is opened, new iodine eluent is dripped from an eluent tank 70 to enter the iodine eluent preparing tank 67, and the circulating liquid flow of the reflux is utilized for homogenization; when the iodine-containing grade of the iodine eluent in the iodine eluent preparing tank 67 is close to the iodine-containing grade difference of the iodine eluent entering the iodine eluent preparing tank 67 from the valve 72, stopping the cyclic regeneration of the iodine eluent on the adsorption tower 34; refluxing the iodine eluent, closing pump 64, heater 63, valve 62; opening the valve 68, starting the pump 69, and refluxing the iodine eluent remained in the adsorption tower 34 to the iodine eluent preparing tank 67 through the valve 33, the valve 31, the valve 68 and the pump 69; cleaning agent or clean water cleans the carrier in the adsorption tower 34, the pump 69 and the valves 68 and 72 are closed, the valves 65 and 62, the valves 31 and 33 are opened, the valves 35 and 49 are opened, the valves 79 are opened, the pump 64 is started, the heater 63 is opened according to the requirements, so that the clean water in the water tank 61 is returned to the water tank 61 through the valves 65 and 64, the heater 63, the valves 62, the valves 31 and 33, the adsorption tower 34, the valves 35 and 49 and 79 to form circulation, the cleaning requirements can be combined, the valves 60 are opened, a certain amount of cleaning agent is added from the cleaning agent tank 59 into the water tank 61, and the cleaning effect on the carrier in the adsorption tower 34 is improved; after the cleaning agent enters the water tank 61, the cleaning agent is homogenized by circulation of liquid flow; after the cleaning, the clean water or the cleaning agent remaining in the adsorption tower 34 is refluxed, the heater 63, the pump 64 and the valve 62 are turned off, the valve 57 is turned on, the pump 58 is started, the cleaning agent remaining in the adsorption tower 34 is refluxed to the water tank 61 through the valve 33, the valve 31, the valve 57 and the pump 58, and the valves and the equipment are turned off after the reflux is completed.
The adsorption tower 34 is removed and replaced. Checking and closing the valve 29, the valve 30, the valve 31, the valve 33, the valve 35, the valve 49, the valve 50 and the valve 37, removing bolts or bayonets on the flange 36 and the flange 32, removing the whole adsorption tower 34, the valve 35 and the valve 33, and forming a closed assembly space by the carrier in the adsorption tower 34, the tower body, the valve 35 and the valve 33 under the closing state of the valve 35 and the valve 33, thereby realizing full-closed management.
The adsorption column 34 is programmed into the final sequence when it is put back into service. After regeneration, cleaning or replacement of the adsorption tower 34, the final adsorption sequencing is incorporated, the three-tower combined serial structure is that the adsorption tower 43 is in the first sequencing, the adsorption tower 25 is in the second sequencing, the adsorption tower 34 is in the third sequencing, and the adsorption tower 34 is incorporated into the third sequencing to operate as follows: valve 21, valve 22, valve 29, valve 30, valve 31, valve 38, valve 40, valve 37, valve 47, valve 48, valve 49, valve 51, valve 52 are closed, valve 39, valve 42, valve 45, valve 46, valve 20, valve 24, valve 26, valve 28, valve 33, valve 35, valve 50 are opened, and the iodine-containing feed liquid is fed into the deiodination feed liquid tank 53 through the pump 17, the flow meter 18, the valve 19, the valve 39, the valve 42, the adsorption tower 43, the valve 44, the valve 46, the valve 20, the valve 24, the adsorption tower 25, the valve 26, the valve 28, the valve 33, the adsorption tower 34, the valve 35 and the valve 50 to form a sequential adsorption sequencing combination of the iodine-containing feed liquid from the adsorption tower 43 to the adsorption tower 25 to the adsorption tower 34.
3. Regeneration of the carrier in the adsorption tower 43:
in order to regenerate the carrier in the adsorption tower 43, the adsorption tower is controlled by a valve to withdraw from adsorption operation, iodine-containing feed liquid can be sequentially adjusted to form a new duplex grouping by taking the adsorption tower 25 as a first order and taking the adsorption tower 34 as a second order through opening and closing the valve, so that continuous operation of production is maintained, and meanwhile, the regeneration, the dismantling, the replacement or the overhaul of the carrier in the adsorption tower 43 is performed on line; after the regeneration of the carrier in the adsorption tower 43 is completed, the carrier is re-organized into a third order for use. The method comprises the following steps: the adsorption tower 43 is first withdrawn from the adsorption operation. Valve 20, valve 22, valve 29, valve 30, valve 31, valve 38, valve 39, valve 37, valve 46, valve 47, valve 48, valve 49 and valve 52 are closed, valve 21, valve 24, valve 26, valve 28, valve 33, valve 35 and valve 50 are opened, iodine-containing feed liquid enters the deiodination feed liquid tank 53 through the pump 17, the flowmeter 18, the valve 19, the valve 21, the valve 24, the adsorption tower 25, the valve 26, the valve 28, the valve 33, the adsorption tower 34, the valve 35 and the valve 50, and can enter other production lines through the valve 54 for use; at this time, the adsorption tower 43 successfully exits the adsorption operation;
the iodine-containing feed liquid remaining in the reflux adsorption column 43. Closing the valves 57, 62, 68 and 72, opening the valves 79, 51, 44, 42, 40 and 55, starting the pumps 56 and the filters 80, and enabling the residual iodine-containing feed liquid in the adsorption tower 43 to flow back to the iodine ion adjusting tank 15 through the valves 42, 40, 55, 56 and the filters 80; the upper port of the adsorption tower is communicated with the pipe orifice on the water tank 61 through a valve 44, a valve 51, a valve 79 and a pipeline to ensure the balance of the air pressure in the tower when the pump 56 is started to reflux the feed liquid in the adsorption tower 43; the sludge generated in the filter 80 is environmentally treated according to the assay analysis properties.
The carrier in the adsorption tower 43 is regenerated and cleaned on line. Firstly, carrying out deiodination regeneration on a carrier in an adsorption tower 43 by adopting an iodine eluent, checking and closing a valve 20, a valve 22, a valve 29, a valve 30, a valve 31, a valve 38, a valve 39, a valve 37, a valve 46, a valve 47, a valve 48, a valve 49, a valve 52, a valve 55, a valve 57, a valve 65, a valve 68 and a valve 79, opening a valve 66, a valve 62, a valve 40, a valve 42, a valve 44, a valve 51 and a valve 72, starting a pump 64, and starting a heater 63 according to the temperature requirement, so that the iodine remover prepared in an iodine eluent preparing tank 67 flows back to the iodine eluent preparing tank 67 through the valve 66, the pump 64, the heater 63, the valve 62, the valve 40, the valve 42, the adsorption tower 43, the valve 44, the valve 51 and the valve 72; when the activity of the eluent in the iodine eluent preparing tank 67 is reduced, a valve 71 is opened, new iodine eluent is dripped from an eluent tank 70 to enter the iodine eluent preparing tank 67, and the circulating liquid flow of the reflux is utilized for homogenization; when the iodine-containing grade of the iodine eluent in the iodine eluent preparing tank 67 is close to the iodine-containing grade difference of the iodine eluent entering the iodine eluent preparing tank 67 from the valve 72, stopping the cyclic regeneration of the iodine eluent on the adsorption tower 43; refluxing the iodine eluent, closing pump 64, heater 63, valve 62; opening the valve 68, starting the pump 69, and refluxing the iodine eluent remained in the adsorption tower 43 to the iodine eluent preparing tank 67 through the valve 42, the valve 40, the valve 68 and the pump 69; cleaning agent or clean water cleans the carrier in the adsorption tower 43, the pump 69 and the valves 68 and 72 are closed, the valves 65 and 62, the valves 40 and 42, the valves 44 and 51 and 79 are opened, the pump valve 64 is started, the heater valve 63 is opened according to the requirements, so that clean water in the pool valve 61 returns to the pool 61 through the valves 65 and 64, the heater 63, the valves 62 and 40, the valves 42 and 79 to form circulation, the cleaning agent can be added into the pool 61 from the cleaning agent tank 59 by opening the valves 60 according to the cleaning requirements, and the cleaning effect on the carrier in the adsorption tower 43 is improved; after the cleaning agent enters the water tank 61, the cleaning agent is homogenized by circulation of liquid flow; after the cleaning, the clean water or the cleaning agent remaining in the adsorption tower 43 is refluxed, the heater 63, the pump 64 and the valve 62 are turned off, the valve 57 is turned on, the pump 58 is started, the cleaning agent remaining in the adsorption tower 43 is refluxed to the water tank 61 through the valve 42, the valve 40, the valve 57 and the pump 58, and the valves and the equipment are turned off after the reflux is completed.
The adsorption tower 43 is removed and replaced. Checking and closing the valve 38, the valve 39, the valve 40, the valve 37, the valve 46, the valve 51, the valve 52, the valve 42 and the valve 44, removing bolts or bayonets on the flange 45 and the flange 41, removing the whole adsorption tower 43, the valve 42 and the valve 44, and forming a closed assembly space by the carrier in the adsorption tower 43, the tower body, the valve 42 and the valve 44 under the closing state of the valve 42 and the valve 44, thereby realizing full-closed management.
The adsorption tower 43 is programmed into the final sequence when it is put back into service. After the regeneration, cleaning or replacement of the adsorption tower 43, the final adsorption sequencing is incorporated, the serial structure of the three towers is that the adsorption tower 25 is in the first sequencing, the adsorption tower 34 is in the second sequencing, and the adsorption tower 43 is in the third sequencing, and the operation of incorporating the adsorption tower 43 into the third sequencing is as follows: valve 20, valve 22, valve 29, valve 30, valve 31, valve 38, valve 39, valve 40, valve 46, valve 47, valve 48, valve 49, valve 50 and valve 51 are closed, valve 21, valve 24, valve 26, valve 28, valve 33, valve 35, valve 37, valve 42, valve 44 and valve 52 are opened, so that iodine-containing feed liquid enters the deiodination feed liquid tank 53 through the pump 17, the flow meter 18, the valve 19, the valve 21, the valve 24, the adsorption tower 25, the valve 26, the valve 28, the valve 33, the adsorption tower 34, the valve 35, the valve 37, the valve 42, the adsorption tower 43, the valve 44 and the valve 52 to form a sequential adsorption sequencing combination of the iodine-containing feed liquid from the adsorption tower 25 to the adsorption tower 34 to the adsorption tower 43.
6. Iodine recovery
According to the assay, when the iodine content carried out in the iodine eluent preparation tank 67 reaches above the economic concentration, the valve 73 is opened to put the iodine-containing eluent in the iodine eluent preparation tank 67 into the crystallization tank 75; starting the stirrer 74, opening the valve 78 to drop the oxidant in the oxidant tank 77 into the crystallization tank 75, wherein the oxidant is hydrogen peroxide; the oxidant is not easy to be added too fast, and can be added for multiple times, stirred and stood for crystallization.
After the iodine crystals in the solution in the crystallization tank 75 are nearly saturated, the suction filter 76 is started to separate the iodine from the solution; the solution returns to the iodine eluent preparing groove 67 for recycling; the filtered iodine is crystal particles, the content is about 90%, and the rest 10% is mainly moisture and a small amount of impurities which cannot be thoroughly removed, so that the iodine can be directly used for synthesizing compounds; can also be refined to produce iodine products with higher purity.
It is to be understood that the above-described embodiments are merely illustrative of the invention and are not intended to limit the practice of the invention. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art; it is not necessary here nor is it exhaustive of all embodiments; and obvious variations or modifications thereof are contemplated as falling within the scope of the present invention.
Claims (11)
1. A method for continuously recovering iodine from low-grade iodine-containing feed liquid is characterized by comprising the following steps:
step one, preprocessing;
the components restricting iodine recovery in the iodine-containing feed liquid and harmful substances are combined for pretreatment and filtration, and the harmful substances are removed;
step two, pH adjustment;
the pH value of the pretreated iodine-containing feed liquid is adjusted to 1-4 by an acid/alkali medicament;
step three, regulating iodide ions;
adding an oxidant in combination with the content of iodide ions in the iodine-containing feed liquid with the adjusted pH value, and adjusting the iodide ions into elemental iodine;
step four, iodine adsorption;
the method comprises the steps of utilizing an adsorption tower and loose carriers arranged in the tower in series to adsorb iodine in iodine-containing feed liquid after iodine ion adjustment, adopting a mode of leading the iodine-containing feed liquid to enter from the lower part and flow out from the upper part of the adsorption tower and then entering from the lower part and flow out from the upper part of the next adsorption tower, and utilizing turbulence, the adsorption effect of different carriers on iodine and multiple enrichment capacity to improve the iodine adsorption rate;
step five, regenerating the carrier;
calculating the iodine adsorption amount and the analysis regeneration time of the carrier in the adsorption tower by using a flowmeter, the iodine content in the iodine-containing feed liquid before adsorption, the carrier loading amount in the adsorption tower, the adsorption rate of different mediums on iodine and the residual iodine content in the iodine-containing feed liquid after adsorption;
When iodine absorbed by the carrier approaches the analysis point, the valve is closed, so that the adsorption tower needing analysis and regeneration temporarily exits the adsorption work, then residual feed liquid is pumped back, then iodine eluent is introduced from the lower part and the upper part of the adsorption tower through the parallel pipeline and flows out, and the iodine eluent is circulated through the eluent groove, so that the carrier can finish the deiodination and regeneration in the adsorption tower;
the concentration of the iodine eluent is combined with the assay data and the regeneration requirement of the carrier in the adsorption tower is adjusted by dripping new eluent;
the carrier is cleaned and regenerated by the iodine eluent, then the residual iodine remover in the adsorption tower is refluxed to an eluent blending tank by a control valve, the carrier in the adsorption tower is cleaned by a cleaning agent or clear water through a parallel pipeline, the cleaning agent or clear water enters from the lower part of the adsorption tower, forms turbulent mixing with the carrier in the tower and then flows out from the upper part of the adsorption tower, and then forms a circulation with the clear water tank, thereby realizing automatic secondary cleaning; the adsorption tower and the carrier are reused after the carrier regeneration and cleaning;
step six, iodine recovery;
the iodine eluent containing iodine after the carrier regeneration is put into an iodine crystallization tank, crystallization precipitation of iodine is gradually realized by dropwise adding hydrogen peroxide for a plurality of times, stirring and standing, and the iodine eluent are separated by suction filtration, so that the iodine recovery is completed; the iodine eluent is recycled.
2. The continuous process for recovering iodine from a low grade iodine containing feed solution according to claim 1, wherein:
the pretreatment in the first step specifically comprises the following steps: firstly adding a pretreatment agent into the iodine-containing feed liquid, and filtering the iodine-containing feed liquid through a filter after full reaction; the filter is any one or a combination of a plurality of microporous filters, membrane filters, fibers and sponges; pretreatment agents include, but are not limited to, various types of oxidizing agents, acids, bases, salt modifiers, neutralizing agents, or adsorbents;
the acid/alkali agent in the second step is any one or a combination of more than one of sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid and sodium hydroxide;
the oxidant in the third step is hydrogen peroxide or sodium nitrite;
the carrier in the adsorption tower in the fourth step is any one or a combination of more than one of active carbon, resin, carbon fiber and graphene;
in the fifth step, the analysis point is that the iodine adsorption amount is 4% of the weight of the carrier; the iodine eluent is sulfurous acid solution, sodium sulfite solution or sodium thiosulfate solution; the cleaning agent is sodium hydroxide solution.
3. The continuous process for recovering iodine from a low-grade iodine-containing feed solution according to claim 2, wherein: in the first step, when the iodine-containing feed liquid contains refractory organic matters, antibiotics and pathogenic bacteria, the iodine-containing feed liquid is subjected to irradiation decomposition, degradation treatment and filtration by adopting electron beams generated by an electron accelerator, and then is subjected to pretreatment.
4. The continuous process for recovering iodine from a low-grade iodine-containing feed solution according to claim 2, wherein: the pH adjustment in the second step is specifically as follows: carrying out assay analysis on the iodine-containing feed liquid from which the harmful substances are removed, dripping corresponding reagents into an acidic reagent tank, a neutral reagent tank or an alkaline reagent tank according to assay data, and adjusting the pH value of the feed liquid to a range of 1-4 so as to meet the later process requirements; filtering out precipitate from the iodine-containing feed liquid with the pH value adjusted through a filter, carrying out assay analysis on the precipitate, and carrying out environmental protection treatment by combining components; the iodine-containing feed liquid after removing the sediment enters an iodine ion adjusting tank.
5. The continuous process for recovering iodine from a low grade iodine containing feed solution according to claim 4, wherein: the iodine ion adjustment in the step three is specifically as follows: the iodine-containing feed liquid with the sediment removed is subjected to assay analysis in an iodine ion regulating tank, and an oxidant is dripped from an oxidant tank to enter the iodine ion regulating tank to convert iodine ions contained in the feed liquid, so that the iodine ions contained in the feed liquid are converted into elemental iodine, and the adsorption of a carrier is facilitated; the oxidant added is mainly hydrogen peroxide, and the addition amount is that the iodine ion rate in the feed liquid is reduced to below 5 percent of the content; according to different components in the feed liquid and combining process requirements, a small amount of other reagents can be added for component adjustment; the iodine-containing feed liquid regulated by iodine ions enters an iodine adsorption process.
6. The continuous process for recovering iodine from a low grade iodine comprising feed liquid according to claim 5, wherein: in the fourth step, more than two adsorption towers are arranged, and each adsorption tower can independently withdraw from the adsorption work without influencing the adsorption work of the other adsorption towers.
7. The continuous process for recovering iodine from a low grade iodine containing feed solution according to claim 6, wherein: in the fourth step, more than two adsorption towers with the same carrier are arranged, and the adsorption towers are used in parallel, in series and in groups, so that the adsorption rate is improved by utilizing the multiple adsorption capacity, and the upper limit of the number of the adsorption towers is flexibly set according to the requirement of the adsorption rate and economic indexes; the same adsorption towers are arranged in each group of adsorption towers to serve as replacement, so that when any one same adsorption tower exits the adsorption work, the adsorption towers are immediately put into the group for replacement; the bridge type pipeline and the valve are arranged on the upper part and the lower part of the adsorption tower group, so that the adsorption sequencing can be flexibly adjusted according to the grouping requirement among each adsorption tower; the adsorption towers are basically woven into the final adsorption sequence according to the first regeneration of the first application and the last application so as to ensure the adsorption efficiency of the adsorption tower group to iodine.
8. The continuous process for recovering iodine from a low grade iodine containing feed solution according to claim 7, wherein: in the fifth step, a reflux device and a residue filtering device are arranged on iodine-containing feed liquid, iodine eluent, cleaning agent or clear water which are remained in the adsorption tower in the carrier regeneration process, so that the influence of residual liquid on the process is reduced; in the carrier regeneration process, a heating device and a thermocouple are arranged on a delivery pipeline of the iodine remover, the cleaning liquid or the clear water, the temperature can be automatically controlled, and after the requirements of the process on the ambient air temperature and the feed liquid temperature are set, the system can be automatically controlled in a reasonable interval.
9. A system for continuously recycling iodine from low-grade iodine-containing feed liquid is characterized in that: the device comprises an iodine-containing feed liquid tank (1), a pretreatment tank (7), a filter I (9), a pH adjusting tank (10), a filter II (14), an iodine ion adjusting tank (15), a pump (17), a flowmeter (18), an adsorption tower group, a deiodination feed liquid storage tank (53), an iodine eluent preparing tank (67), an iodine eluent tank (70), a water tank (61), a cleaning agent tank (59), a crystallization tank (75) and a suction filter (76);
the iodine-containing feed liquid tank (1), the pretreatment tank (7), the filter I (9), the pH adjusting tank (10), the filter II (14), the iodine ion adjusting tank (15), the pump (17), the flowmeter (18), the adsorption tower group and the deiodination feed liquid storage tank (53) are sequentially communicated;
the adsorption tower group consists of more than two adsorption towers which are connected in series, a carrier for adsorbing iodine is arranged in each adsorption tower, a liquid inlet is arranged at the bottom of each adsorption tower, and a liquid outlet is arranged at the top of each adsorption tower;
the flowmeter (18) is communicated with the liquid inlet of each adsorption tower in the adsorption tower group, and each passage is provided with a valve and a flange; the liquid outlet of each adsorption tower in the adsorption tower group is communicated with the deiodination liquid storage tank (18) and each passage is provided with a valve and a flange; each passage is provided with a control valve, and each adsorption tower in the adsorption tower group can independently withdraw from adsorption work without affecting the adsorption work of other adsorption towers;
The water tank (61) is communicated with the liquid inlet of each adsorption tower in the adsorption tower group through a pump, and each passage is provided with a valve; the water tank (61) is also communicated with the liquid outlet of each adsorption tower in the adsorption tower group, and each passage is provided with a valve;
the iodine eluent mixing tank (67) is communicated with the liquid inlet of each adsorption tower in the adsorption tower group through a pump, and each passage is provided with a valve; the iodine eluent mixing tank (67) is also communicated with the liquid outlet of each adsorption tower in the adsorption tower group, and each passage is provided with a valve;
the iodine eluent preparing groove (67) is communicated with the crystallizing groove (75) and valves are arranged on the passages;
the liquid inlet of the suction filter (76) is communicated with the crystallization tank (75), and the liquid outlet of the suction filter (76) is communicated with the iodine eluent mixing tank (67).
10. An adsorption tower comprises a tower body; the method is characterized in that: the bottom of the tower body is provided with a liquid inlet, the top of the tower body is provided with a liquid outlet, two filter screens are arranged in the tower body, and an adsorption carrier is loaded between the filter screens; the liquid inlet and the liquid outlet are also provided with valves and flanges; the valve and the flange at two ends of the tower body form a closed assembly structure for the adsorption tower and the adsorption carrier, so that the adsorption tower is integrally disassembled, replaced and transported after the valve is closed, and the carrier is prevented from being exposed in an irregular place to generate potential safety hazards and environmental protection hazards.
11. Use of an adsorption column according to claim 10 in a continuous process for recovering iodine from a low-grade iodine-containing feed liquid, characterized in that: the adsorption towers are provided with more than two adsorption towers and are used in a parallel, serial and marshalling connection mode; the bridge type pipeline and the valve are arranged on the upper portion and the lower portion of the adsorption tower group, and the adsorption sequencing can be flexibly adjusted by combining grouping among the adsorption towers through controlling the valve.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211367582.8A CN116812872A (en) | 2022-11-03 | 2022-11-03 | Method and system for continuously recycling iodine from low-grade iodine-containing feed liquid |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211367582.8A CN116812872A (en) | 2022-11-03 | 2022-11-03 | Method and system for continuously recycling iodine from low-grade iodine-containing feed liquid |
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| CN202211367582.8A Pending CN116812872A (en) | 2022-11-03 | 2022-11-03 | Method and system for continuously recycling iodine from low-grade iodine-containing feed liquid |
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| CN (1) | CN116812872A (en) |
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