CN219991386U - System for phosphoric acid is retrieved to iron phosphate waste water - Google Patents
System for phosphoric acid is retrieved to iron phosphate waste water Download PDFInfo
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- CN219991386U CN219991386U CN202321664088.8U CN202321664088U CN219991386U CN 219991386 U CN219991386 U CN 219991386U CN 202321664088 U CN202321664088 U CN 202321664088U CN 219991386 U CN219991386 U CN 219991386U
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- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 title claims abstract description 106
- 229910000147 aluminium phosphate Inorganic materials 0.000 title claims abstract description 53
- WBJZTOZJJYAKHQ-UHFFFAOYSA-K iron(3+) phosphate Chemical compound [Fe+3].[O-]P([O-])([O-])=O WBJZTOZJJYAKHQ-UHFFFAOYSA-K 0.000 title claims abstract description 23
- 239000002351 wastewater Substances 0.000 title claims abstract description 21
- 229910000398 iron phosphate Inorganic materials 0.000 title claims abstract description 19
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 343
- 238000001223 reverse osmosis Methods 0.000 claims abstract description 173
- 238000001728 nano-filtration Methods 0.000 claims abstract description 153
- 238000000108 ultra-filtration Methods 0.000 claims abstract description 127
- 238000004519 manufacturing process Methods 0.000 claims abstract description 72
- 238000004064 recycling Methods 0.000 claims abstract description 16
- 239000012141 concentrate Substances 0.000 claims abstract description 9
- 239000012528 membrane Substances 0.000 claims description 116
- 238000004140 cleaning Methods 0.000 claims description 88
- 238000010926 purge Methods 0.000 claims description 3
- 150000001768 cations Chemical class 0.000 abstract description 15
- 229910052751 metal Inorganic materials 0.000 abstract description 9
- 239000002184 metal Substances 0.000 abstract description 9
- 238000001914 filtration Methods 0.000 abstract description 7
- 239000003344 environmental pollutant Substances 0.000 abstract description 5
- 231100000719 pollutant Toxicity 0.000 abstract description 5
- 229910021645 metal ion Inorganic materials 0.000 abstract description 4
- 238000009825 accumulation Methods 0.000 abstract description 3
- 239000003814 drug Substances 0.000 abstract description 2
- 238000005265 energy consumption Methods 0.000 abstract description 2
- 230000010354 integration Effects 0.000 abstract description 2
- 238000004065 wastewater treatment Methods 0.000 abstract description 2
- 239000000243 solution Substances 0.000 description 33
- 238000005406 washing Methods 0.000 description 23
- 239000000126 substance Substances 0.000 description 22
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 description 21
- 238000010992 reflux Methods 0.000 description 14
- 238000000034 method Methods 0.000 description 13
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 11
- 238000011010 flushing procedure Methods 0.000 description 8
- 238000011084 recovery Methods 0.000 description 7
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 6
- 239000012535 impurity Substances 0.000 description 6
- 239000007788 liquid Substances 0.000 description 6
- 229910052742 iron Inorganic materials 0.000 description 5
- 239000012452 mother liquor Substances 0.000 description 5
- 238000007254 oxidation reaction Methods 0.000 description 5
- 238000002791 soaking Methods 0.000 description 5
- 239000005955 Ferric phosphate Substances 0.000 description 4
- 239000002253 acid Substances 0.000 description 4
- 229940032958 ferric phosphate Drugs 0.000 description 4
- 229910000399 iron(III) phosphate Inorganic materials 0.000 description 4
- 230000003647 oxidation Effects 0.000 description 4
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 3
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 229910052748 manganese Inorganic materials 0.000 description 3
- 239000011572 manganese Substances 0.000 description 3
- 229910017604 nitric acid Inorganic materials 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 238000005273 aeration Methods 0.000 description 2
- 125000004122 cyclic group Chemical group 0.000 description 2
- 239000011790 ferrous sulphate Substances 0.000 description 2
- 235000003891 ferrous sulphate Nutrition 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- 229910002804 graphite Inorganic materials 0.000 description 2
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 description 2
- 229910000359 iron(II) sulfate Inorganic materials 0.000 description 2
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000007935 neutral effect Effects 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- 239000002243 precursor Substances 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- LFVGISIMTYGQHF-UHFFFAOYSA-N ammonium dihydrogen phosphate Chemical compound [NH4+].OP(O)([O-])=O LFVGISIMTYGQHF-UHFFFAOYSA-N 0.000 description 1
- 229910000387 ammonium dihydrogen phosphate Inorganic materials 0.000 description 1
- 235000011114 ammonium hydroxide Nutrition 0.000 description 1
- 150000003863 ammonium salts Chemical class 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 238000011001 backwashing Methods 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 239000012459 cleaning agent Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 229960004887 ferric hydroxide Drugs 0.000 description 1
- 239000003337 fertilizer Substances 0.000 description 1
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N iron oxide Inorganic materials [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 1
- IEECXTSVVFWGSE-UHFFFAOYSA-M iron(3+);oxygen(2-);hydroxide Chemical compound [OH-].[O-2].[Fe+3] IEECXTSVVFWGSE-UHFFFAOYSA-M 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 1
- 235000019837 monoammonium phosphate Nutrition 0.000 description 1
- 239000006012 monoammonium phosphate Substances 0.000 description 1
- 239000005416 organic matter Substances 0.000 description 1
- NDLPOXTZKUMGOV-UHFFFAOYSA-N oxo(oxoferriooxy)iron hydrate Chemical compound O.O=[Fe]O[Fe]=O NDLPOXTZKUMGOV-UHFFFAOYSA-N 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
Landscapes
- Separation Using Semi-Permeable Membranes (AREA)
Abstract
The utility model belongs to the field of wastewater treatment, and discloses a system for recycling phosphoric acid from wastewater in iron phosphate production. Comprises a raw water tank, an ultrafiltration filter unit, a first-stage nanofiltration filter unit, a first-stage reverse osmosis unit, a second-stage nanofiltration unit and a second-stage reverse osmosis unit. The system of the utility model adopts two-stage nanofiltration and reverse osmosis to purify and concentrate the wastewater of iron phosphate production, and the nanofiltration removes metal cations, which is used as pretreatment of reverse osmosis, can slow down the accumulation of metal ions on the surface of the reverse osmosis, and prolongs the service life of the reverse osmosis. The system does not need repeated acid-base regulation, so that the medicament is saved; the repeated heat exchangers such as temperature rise, temperature reduction and the like are not needed, and the energy consumption is low; the normal temperature physical filtration is adopted, no external pollutant is brought, the system integration level is high, the popularization is convenient, and the gradient recycling of phosphoric acid can be realized.
Description
Technical Field
The utility model belongs to the field of wastewater treatment, and relates to a system for recycling phosphoric acid from wastewater in iron phosphate production.
Background
In recent years, the capacity of lithium iron phosphate has been increasing year by year due to the development of new energy batteries and energy storage industries. Iron phosphate is also in increasing demand as a precursor for lithium iron phosphate batteries. The main production process of the ferric phosphate used as a precursor comprises the following steps: (1) The ferrous sulfate reacts with sufficient phosphoric acid and hydrogen peroxide through oxidation and precipitation, alkali or ammonia water is added to adjust the pH value, and the precipitation of ferric phosphate is promoted; (2) Ferrous sulfate reacts with industrial monoammonium phosphate, and ferric phosphate is generated under the condition that hydrogen peroxide promotes oxidization; (3) Iron powder, iron blocks, ferric oxide or ferric hydroxide directly react with phosphoric acid, and hydrogen peroxide is added for oxidation to promote the generation of ferric phosphate.
The process (1) and the process (2) are widely applied, the generated mother liquor and washing water treatment process are relatively mature, and ammonium salt is obtained through purification, concentration and evaporation and is used for preparing chemical fertilizers.
The iron phosphate line of the prior art (3) is continuously popularized in industry, and the generated washing water and mother liquor do not contain sulfate radical, so the method has the feasibility of recycling phosphoric acid.
Aiming at the iron phosphate production wastewater without sulfate radical, the patent with the publication number of CN114873824A discloses a treatment method of the battery grade iron phosphate production wastewater, wherein the ultrafiltration and two-stage RO+ graphite evaporator technology is adopted to concentrate phosphoric acid and recycle the phosphoric acid, but the actual phosphoric acid wastewater contains more metal cation impurities, especially iron, manganese, calcium, magnesium and the like, if the phosphoric acid wastewater directly enters a reverse osmosis system or a graphite evaporator, the problems of system scaling, insufficient purity of the recovered phosphoric acid and the like are caused.
Disclosure of Invention
Aiming at the problems in the prior art, the utility model aims to provide a system for recycling phosphoric acid from iron phosphate production wastewater, which adopts two-stage nanofiltration and reverse osmosis to purify and concentrate the iron phosphate production wastewater to obtain qualified phosphoric acid solution.
In order to achieve the above purpose, the technical scheme adopted by the utility model is as follows:
the system for recycling phosphoric acid from waste water in iron phosphate production comprises a raw water tank, an ultrafiltration filter unit, a first-stage nanofiltration filter unit, a first-stage reverse osmosis unit, a second-stage nanofiltration unit and a second-stage reverse osmosis unit, wherein:
the ultrafiltration unit comprises an ultrafiltration membrane component connected with the raw water tank, and the water producing end of the ultrafiltration membrane component is connected with an ultrafiltration water producing tank;
the primary nanofiltration unit comprises a primary nanofiltration membrane component connected with an ultrafiltration water production tank, and the water production end of the primary nanofiltration membrane component is connected with the primary nanofiltration water production tank;
the first-stage reverse osmosis unit comprises a first-stage reverse osmosis membrane component connected with a first-stage nanofiltration water production tank, the water production end of the first-stage reverse osmosis membrane component is connected with the first-stage reverse osmosis water production tank, and the concentrated water end of the first-stage reverse osmosis membrane component is connected with the first-stage reverse osmosis concentrated water tank;
the secondary nanofiltration unit comprises a secondary nanofiltration membrane component connected with the primary reverse osmosis concentrated water tank, and the water producing end of the secondary nanofiltration membrane component is connected with a secondary nanofiltration water producing tank;
the secondary reverse osmosis unit comprises a secondary reverse osmosis membrane assembly connected with a secondary nanofiltration water production tank, the water production end of the secondary reverse osmosis membrane assembly is connected with the secondary reverse osmosis water production tank, and the dense water end of the secondary reverse osmosis membrane assembly is connected with the secondary reverse osmosis dense water tank.
Further, the ultrafiltration filter unit further comprises an ultrafiltration cleaning water tank, and the ultrafiltration cleaning water tank is connected with the water inlet end and the concentrated water end of the ultrafiltration membrane component.
Further preferably, the ultrafiltration cleaning water tank is connected with the water producing end of the ultrafiltration membrane component through an ultrafiltration backwash pump and a pipeline.
Further preferably, the ultrafiltration cleaning water tank is connected with the water producing end of the primary reverse osmosis membrane component and the water producing end of the secondary reverse osmosis membrane component.
Further, the first-stage nanofiltration unit further comprises a first-stage nanofiltration cleaning water tank, and the first-stage nanofiltration cleaning water tank is connected with the water inlet end and the concentrated water end of the first-stage nanofiltration membrane component.
The first-stage reverse osmosis unit further comprises a first-stage reverse osmosis cleaning water tank, and the first-stage reverse osmosis cleaning water tank is connected with the water inlet end and the concentrated water end of the first-stage reverse osmosis membrane component.
Further, the system also comprises a secondary cleaning water tank; the secondary cleaning water tank is connected with the water inlet end and the concentrated water end of the secondary nanofiltration membrane component; the second-stage cleaning water tank is connected with the water inlet end and the concentrated water end of the second-stage reverse osmosis membrane component.
Further, the concentrated water end of the first-stage nanofiltration membrane component is connected with a raw water tank.
Further, the concentrated water end of the secondary nanofiltration membrane component is connected with a raw water tank.
Further:
the raw water tank is connected with an ultrafiltration membrane component through an ultrafiltration water inlet pump and a pipeline;
the ultrafiltration water producing tank is connected with the primary nanofiltration membrane component through a primary nanofiltration water inlet pump and a pipeline;
the first-stage nanofiltration product water tank is connected with a first-stage reverse osmosis membrane assembly through a first-stage reverse osmosis water inlet pump and a pipeline;
the first-stage reverse osmosis concentrated water tank is connected with a second-stage nanofiltration membrane component through a second-stage nanofiltration water inlet pump and a pipeline;
the secondary nanofiltration water production tank is connected with the secondary reverse osmosis membrane assembly through a secondary reverse osmosis water inlet pump and a pipeline.
Further preferably, a valve is provided on the pipe.
Compared with the prior art, the utility model has the beneficial effects that:
(1) The system of the utility model adopts two-stage nanofiltration and reverse osmosis to purify and concentrate the wastewater of iron phosphate production, and the nanofiltration removes metal cations, which is used as pretreatment of reverse osmosis, can slow down the accumulation of metal ions on the surface of the reverse osmosis, and prolongs the service life of the reverse osmosis. The system does not need repeated acid-base regulation, so that the medicament is saved; the repeated heat exchangers such as temperature rise, temperature reduction and the like are not needed, and the energy consumption is low; the normal temperature physical filtration is adopted, no external pollutant is brought, the system integration level is high, the popularization is convenient, and the gradient recycling of phosphoric acid can be realized.
(2) The system can effectively clean and recover the first-stage nanofiltration by using citric acid and nitric acid, and can effectively clean and recover the first-stage reverse osmosis progress by using citric acid and phosphoric acid. And under each working condition, two kinds of acid are used alternately, so that accumulation of metal ions on the membrane surface is effectively removed, and a better cleaning effect can be achieved. The two-stage nanofiltration and the two-stage reverse osmosis share the same chemical cleaning water tank, so that the equipment investment is reduced.
(3) The ultrafiltration, nanofiltration and reverse osmosis can be designed to run at low pressure and low load, the cleaning period is shorter than the conventional reverse osmosis cleaning period, and the nanofiltration and reverse osmosis are synchronously cleaned, so that the long-term stable running of the system is ensured.
(4) The backwash water of a general ultrafiltration system is membrane produced water, and is physically cleaned by adopting a gas-water cleaning or gas-water backwash process, and the recovery rate of the system is 90% -95%; the system of the utility model considers that raw water is a high-value phosphoric acid solution, ensures the filtration and impurity removal of raw water to the maximum extent, and the ultrafiltration cleaning water tank is connected with the water producing end of the primary reverse osmosis membrane module and the water producing end of the secondary reverse osmosis membrane module, the cleaning water connected with the ultrafiltration filter unit adopts reverse osmosis water producing, and the water recovery rate is improved to 99% -99.5% by adopting forward flushing and back flushing. The loss of the raw material liquid can be reduced to the greatest extent, and meanwhile, the oxidation of aeration to metal ions in water is avoided.
Drawings
The accompanying drawings are included to provide a further understanding of the utility model and are incorporated in and constitute a part of this specification, illustrate the utility model and together with the embodiments of the utility model, serve to explain the utility model. In the drawings:
FIG. 1 is a schematic diagram of a system for recovering phosphoric acid from iron phosphate production wastewater according to the present utility model;
in the figure: 1 raw water tank, 2 ultrafiltration water inlet pump front valve, 3 ultrafiltration water inlet pump, 4 ultrafiltration water inlet pump rear valve, 5 ultrafiltration membrane component, 6 ultrafiltration water producing valve, 7 ultrafiltration water producing tank, 8 level nanofiltration water inlet pump front valve, 9 level nanofiltration water inlet pump, 10 level nanofiltration water inlet pump rear valve, 11 level nanofiltration membrane component, 12 level nanofiltration water producing valve, 13 level nanofiltration water producing tank, 14 level reverse osmosis water inlet pump front valve, 15 level reverse osmosis water inlet pump, 16 level reverse osmosis water inlet pump rear valve, 17 level reverse osmosis membrane component, 18 level reverse osmosis water producing tank, 19 level reverse osmosis water concentrating valve, 20 level reverse osmosis water concentrating tank, 21 level nanofiltration water inlet pump front valve, 22 level nanofiltration water inlet pump, 23 level nanofiltration water inlet pump rear valve, 24 level nanofiltration water producing valve, 26 level nanofiltration water producing tank, 27 level reverse osmosis water inlet pump regulating valve a 28 second-level reverse osmosis water inlet pump, a 29 second-level reverse osmosis water inlet pump back valve, a 30 second-level reverse osmosis membrane component, a 31 second-level reverse osmosis water production tank, a 32 second-level reverse osmosis water valve, a 33 second-level reverse osmosis water tank, a 34 second-level reverse osmosis cleaning reflux valve, a 35 second-level reverse osmosis cleaning water inlet valve, a 36 second-level nanofiltration water valve, a 37 second-level nanofiltration water washing reflux valve, a 38 second-level cleaning water tank, a 39 second-level nanofiltration water washing inlet valve, a 40 first-level reverse osmosis cleaning reflux valve, a 41 first-level reverse osmosis cleaning water inlet valve, a 42 first-level reverse osmosis cleaning water tank, a 43 first-level nanofiltration water valve, a 44 first-level nanofiltration water washing reflux valve, a 45 first-level nanofiltration water washing inlet valve, a 46 ultrafiltration cleaning water tank, a 47 ultrafiltration cleaning reflux valve, a 48 ultrafiltration backwash pump front valve, a 49 ultrafiltration backwash pump, a 50 ultrafiltration pump back valve, a 51 ultrafiltration upper discharge valve, a 52 ultrafiltration lower discharge valve, a 53 ultrafiltration cleaning water inlet valve, 54-stage nanofiltration cleaning water tank.
Detailed Description
The present utility model will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments are shown, for the purpose of illustrating the utility model, but the scope of the utility model is not limited to the specific embodiments shown.
Unless defined otherwise, all technical and scientific terms used hereinafter have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the scope of the present utility model.
Unless otherwise specifically indicated, the various raw materials, reagents, instruments, equipment and the like used in the present utility model are commercially available or may be prepared by existing methods.
Example 1
As shown in fig. 1, the embodiment discloses a system for recycling phosphoric acid from iron phosphate production wastewater, which comprises a raw water tank 1, an ultrafiltration filter unit, a first nanofiltration filter unit, a first reverse osmosis unit, a second nanofiltration unit and a second reverse osmosis unit.
The ultrafiltration filter unit comprises an ultrafiltration membrane component 5 connected with the raw water tank 1, and the water producing end of the ultrafiltration membrane component 5 is connected with an ultrafiltration water producing tank 7. An ultrafiltration upper drain pipeline is arranged at the concentrated water end of the ultrafiltration membrane component 5, an ultrafiltration lower drain pipeline is arranged at the bottom end of the ultrafiltration membrane component 5, an ultrafiltration upper drain valve 51 is arranged on the ultrafiltration upper drain pipeline, and an ultrafiltration lower drain valve 52 is arranged on the ultrafiltration lower drain pipeline; the ultrafiltration filter unit further comprises an ultrafiltration cleaning water tank 46, wherein the ultrafiltration cleaning water tank 46 is connected with the water inlet end of the ultrafiltration membrane component 5 through a pipeline and an ultrafiltration cleaning water inlet valve 53, and the ultrafiltration cleaning water tank 46 is connected with the concentrated water end of the ultrafiltration membrane component 5 through a pipeline and an ultrafiltration cleaning reflux valve 47 to form circulation. The ultrafiltration cleaning water tank 46 is connected with the water producing end of the ultrafiltration membrane component 5 through an ultrafiltration backwash pump front valve 48, an ultrafiltration backwash pump 49, an ultrafiltration backwash pump rear valve 50 and pipelines.
The primary nanofiltration unit comprises a primary nanofiltration membrane component 11 connected with the ultrafiltration water production tank 7, and the water production end of the primary nanofiltration membrane component 11 is connected with a primary nanofiltration water production tank 13. The primary nanofiltration unit further comprises a primary nanofiltration cleaning water tank 54, the primary nanofiltration washing water tank 54 is connected with the water inlet end of the primary nanofiltration membrane assembly 11 through a pipeline and a primary nanofiltration washing water inlet valve 45, and the primary nanofiltration washing water tank 54 is connected with the concentrated water end of the primary nanofiltration membrane assembly 11 through a pipeline and a primary nanofiltration washing reflux valve 44 to form circulation.
The primary reverse osmosis unit comprises a primary reverse osmosis membrane assembly 17 connected with a primary nanofiltration water production tank 13, the water production end of the primary reverse osmosis membrane assembly 17 is connected with a primary reverse osmosis water production tank 18, and the concentrated water end of the primary reverse osmosis membrane assembly 17 is connected with a primary reverse osmosis concentrated water tank 20; the primary reverse osmosis unit further comprises a primary reverse osmosis cleaning water tank 42, the primary reverse osmosis cleaning water tank 42 is connected with the water inlet end of the primary reverse osmosis membrane assembly 17 through a pipeline and a primary reverse osmosis cleaning water inlet valve 41, and the primary reverse osmosis cleaning water tank 42 is connected with the concentrated water end of the primary reverse osmosis membrane assembly 17 through a pipeline and a primary reverse osmosis cleaning reflux valve 40 to form circulation.
The secondary nanofiltration unit comprises a secondary nanofiltration membrane assembly 24 connected with the primary reverse osmosis concentrated water tank 20, and the water producing end of the secondary nanofiltration membrane assembly 24 is connected with a secondary nanofiltration water producing tank 26;
the secondary reverse osmosis unit comprises a secondary reverse osmosis membrane assembly 30 connected with a secondary nanofiltration water production tank 26, the water production end of the secondary reverse osmosis membrane assembly 30 is connected with a secondary reverse osmosis water production tank 31, and the concentrated water end of the secondary reverse osmosis membrane assembly 30 is connected with a secondary reverse osmosis concentrated water tank 33.
The system also includes a secondary purge tank 38; the secondary cleaning water tank 38 is connected with the water inlet end of the secondary nanofiltration membrane assembly 24 through a pipeline and a secondary nanofiltration washing water inlet valve 39, and the secondary cleaning water tank 38 is connected with the concentrated water end of the secondary nanofiltration membrane assembly 24 through a pipeline and a secondary nanofiltration washing reflux valve 37 to form circulation; the secondary cleaning water tank 38 is connected with the water inlet end of the secondary reverse osmosis membrane assembly 30 through a pipeline and the secondary reverse osmosis cleaning water inlet valve 35, and the secondary cleaning water tank 38 is connected with the concentrated water end of the secondary reverse osmosis membrane assembly 30 through a pipeline and the secondary reverse osmosis cleaning reflux valve 34 to form circulation.
In this embodiment, the concentrated water end of the first-stage nanofiltration membrane module 11 is connected with the raw water tank 1 through a pipeline and a first-stage nanofiltration concentrated water valve 43; the concentrated water end of the secondary nanofiltration membrane assembly 24 is connected with the raw water tank 1 through a pipeline and a secondary nanofiltration concentrated water valve 36. The ultrafiltration cleaning water tank 46 is connected with the water producing end of the primary reverse osmosis membrane component 17 and the water producing end of the secondary reverse osmosis membrane component 30.
The raw water tank 1 is connected with an ultrafiltration membrane component 5 through an ultrafiltration water inlet pump front valve 2, an ultrafiltration water inlet pump 3, an ultrafiltration water inlet pump rear valve 4 and a pipeline;
the ultrafiltration water producing tank is connected with a primary nanofiltration membrane component 11 through a primary nanofiltration water inlet pump front valve 8, a primary nanofiltration water inlet pump 9, a primary nanofiltration water inlet pump rear valve 10 and a pipeline;
the first-stage nanofiltration water production tank 13 is connected with a first-stage reverse osmosis membrane module 17 through a first-stage reverse osmosis water inlet pump front valve 14, a first-stage reverse osmosis water inlet pump 15, a first-stage reverse osmosis water inlet pump rear valve 16 and a pipeline;
the first-stage reverse osmosis concentrated water tank 20 is connected with a second-stage nanofiltration membrane component 24 through a second-stage nanofiltration water inlet pump front valve 21, a second-stage nanofiltration water inlet pump 22, a second-stage nanofiltration water inlet pump rear valve 23 and a pipeline;
the secondary nanofiltration water production tank 26 is connected with a secondary reverse osmosis membrane assembly 30 through a secondary reverse osmosis water inlet regulating valve 27, a secondary reverse osmosis water inlet pump 28, a secondary reverse osmosis water inlet pump rear valve 29 and a pipeline.
As one of the preferable modes of the present embodiment, the system operation principle of the present embodiment is as follows:
the phosphoric acid solution containing impurities in the raw water tank 1 is lifted by the ultrafiltration water inlet pump 3, enters the ultrafiltration membrane component 5, and entraps suspended matters and impurities to obtain transparent and clear produced water, and the transparent and clear produced water enters the ultrafiltration water production tank 7. The impurity-removed phosphoric acid solution in the ultrafiltration water production tank 7 is pumped into the first-stage nanofiltration membrane component 11 through the first-stage nanofiltration water inlet pump 9, the phosphoric acid solution with metal cations removed enters the first-stage nanofiltration water production tank 13, the phosphoric acid solution with cations removed is pumped into the first-stage reverse osmosis water production tank 13 through the first-stage reverse osmosis water inlet pump 15, the low-concentration phosphoric acid solution is concentrated through the first-stage reverse osmosis component 17, the phosphoric acid solution with concentration of 2-4 times enters the first-stage reverse osmosis concentrated water tank 20, and the produced water enters the first-stage reverse osmosis water production tank 18 for recycling.
The concentrated phosphoric acid solution in the first reverse osmosis concentrate tank 20 increases in phosphoric acid concentration, and consequently increases in metal cation concentration, so that further cation removal is required. The phosphoric acid solution in the first-stage reverse osmosis concentrated water tank 20 is pumped into the second-stage nanofiltration water inlet pump 22 and the second-stage nanofiltration membrane component 24 to remove metal cations, the produced water enters the second-stage nanofiltration water production tank 26, the phosphoric acid solution in the second-stage nanofiltration water production tank 26 is pumped into the second-stage reverse osmosis component 30 through the second-stage reverse osmosis water inlet pump 28, after phosphoric acid is further concentrated, the concentration multiple is 1-3 times, the produced water enters the second-stage reverse osmosis water production tank 31, and the concentrated water enters the second-stage reverse osmosis concentrated water tank 33, so that the phosphoric acid solution with the concentration of 20% -30% meeting the recycling requirement is obtained.
The phosphoric acid solution in the first-stage reverse osmosis concentrated water tank 20, the second-stage nanofiltration water production tank 26 and the second-stage reverse osmosis concentrated water tank 33 all reach the recycling standard, and can be recycled step by step according to the requirements of the front-stage production process or can be recycled after the high-concentration phosphoric acid solution is obtained.
The waste water from iron phosphate production contains trace organic matter, COD is less than 50mg/L, the pollutant is mainly metal salt, the aqueous solution is strong acid, and air washing is easy to lead to oxidation of the metal salt in the solution, so that the ultrafiltration filter unit adopts an external pressing membrane, dead end full-scale filtration is performed, aeration cleaning is not performed, and chemical cleaning is performed after … … n cycles of water production, positive flushing, water production and back flushing are performed. The operation steps are as follows:
ultrafiltration water production stage: the front valve 2 of the ultrafiltration water inlet pump and the ultrafiltration water producing valve 6 are opened, and other valves and pumps of the ultrafiltration filter unit are closed. The raw water enters an ultrafiltration water production tank 7 after being filtered and decontaminated by an ultrafiltration membrane component 5, the water production period of the filtration mother liquor is 20-30 min, and the water production period of the filtration washing water is 40-60 min. The end of the water production enters the positive washing stage.
Ultrafiltration forward rinse stage: the ultrafiltration cleaning water inlet valve 53, the ultrafiltration water inlet pump 3, the ultrafiltration water inlet pump rear valve 4 and the ultrafiltration upper discharge valve 51 are opened, the ultrafiltration water inlet pump 3 is utilized to pump reverse osmosis product water in the ultrafiltration cleaning water tank 46 into the ultrafiltration membrane component 5, and the lower inlet and upper outlet modes are adopted to flush pollutants on the membrane surface. After the positive flushing is finished, the ultrafiltration lower discharge valve 52 is opened, the cleaning water in the ultrafiltration membrane component 5 is emptied, and the ultrafiltration water production stage is entered. The positive washing time is 30-60 s, and the water yield of the washing water is 3-6 times of the water yield.
Ultrafiltration back flush stage: the ultrafiltration backwash pump front valve 48, the ultrafiltration backwash pump 49, the ultrafiltration backwash pump rear valve 50 and the ultrafiltration upper discharge valve 51 are opened, reverse osmosis water in the ultrafiltration cleaning water tank 46 is backwashed from the membrane wire inside to clean the ultrafiltration membrane component 5, the ultrafiltration lower discharge valve 52 is opened after the backwashing is finished, cleaning water in the ultrafiltration membrane component 5 is emptied, and the ultrafiltration water enters the ultrafiltration water production stage. The back flushing time is 30-60 s, and the back flushing water quantity is 1.5-3 times of the water yield.
Ultrafiltration chemical cleaning stage: the ultrafiltration cleaning water inlet valve 53, the ultrafiltration water inlet pump 3, the ultrafiltration water inlet pump rear valve 4 and the ultrafiltration cleaning reflux valve 47 are opened, and the ultrafiltration cleaning water tank 46 is pumped into the membrane module 5 by the ultrafiltration water inlet pump 3 and circulated. And (3) circulating for 1h, soaking for 1h, and alternately carrying out until the pH value is no longer changed, evacuating water in the assembly, and flushing with clear water to be neutral. Entering into the water producing stage. The chemical cleaning liquid is a citric acid solution with the concentration of 0.05-0.2 mol/L, a sodium hydroxide solution with the concentration of 200-500 ppm and a phosphoric acid solution with the concentration of 0.5-1%.
The operation conditions of the first-stage nanofiltration filter unit, the first-stage reverse osmosis unit, the second-stage nanofiltration unit and the second-stage reverse osmosis unit comprise: water production and chemical cleaning. Wherein the first-stage nanofiltration filter unit and the first-stage reverse osmosis unit are respectively provided with an independent cleaning water tank, and the second-stage nanofiltration unit and the second-stage reverse osmosis unit share one cleaning water tank. The water production process is not repeated.
The chemical cleaning procedure is as follows:
first-stage nanofiltration chemical cleaning: the first-stage nanofiltration water-washing valve 45, the first-stage nanofiltration water inlet pump 9, the first-stage nanofiltration water inlet pump rear valve 10 and the first-stage nanofiltration water-washing reflux valve 44 are opened, and the other valves of the first-stage nanofiltration filter unit are closed. The chemical cleaning liquid in the first-stage nanofiltration cleaning water tank 54 is pumped into the first-stage nanofiltration membrane assembly 11, and the chemical cleaning liquid is circularly soaked for 1h and 1h, and alternately runs, so that the pH of the chemical cleaning liquid is not changed any more. 0.05-0.2 mol/L citric acid solution or 0.01-0.1 mol/L nitric acid solution of chemical cleaning solution.
Primary reverse osmosis chemical cleaning: the method comprises the steps of starting a first-stage reverse osmosis cleaning water inlet valve 41, a first-stage reverse osmosis water inlet pump 15, a first-stage reverse osmosis water inlet pump rear valve 16 and a first-stage reverse osmosis cleaning reflux valve 40, pumping chemical cleaning liquid in a first-stage reverse osmosis cleaning water tank 42 into a first-stage reverse osmosis assembly 17, circularly soaking for 1h, alternately running, and keeping the pH of the chemical cleaning unchanged. 0.05-0.2 mol/L citric acid solution or 0.05-0.1 mol/L phosphoric acid solution of chemical cleaning solution.
After the primary nanofiltration and the reverse osmosis are used for purifying and concentrating phosphoric acid, the content of impurities and cations in the phosphoric acid solution is obviously reduced, the secondary nanofiltration and the secondary reverse osmosis are used for further purifying and concentrating the phosphoric acid solution, and a small amount of trapped metal cations are retained, so that the secondary nanofiltration unit and the secondary reverse osmosis unit share a set of chemical cleaning water tank, and the cleaning agents are citric acid solutions of 0.05-0.2 mol/L.
The operation steps are as follows:
the second nanofiltration water inlet valve 39, the second nanofiltration water inlet pump 22, the second nanofiltration water inlet pump rear valve 23, the second nanofiltration water outlet valve 37 and the second nanofiltration water outlet valve 37 are opened, and the other valves of the second nanofiltration unit are closed. The chemical cleaning solution in the secondary cleaning water tank 38 is pumped into the secondary nanofiltration assembly 24, and is circularly soaked for 1 hour, and the soaking is alternately operated for 1 hour until the pH is stable and unchanged.
Secondary reverse osmosis chemical cleaning: the second-stage nanofiltration washing water inlet valve 39, the second-stage reverse osmosis water inlet pump 28, the second-stage reverse osmosis water inlet pump rear valve 29, the second-stage reverse osmosis washing reflux valve 34 and other valves of the second-stage reverse osmosis unit are opened. The chemical cleaning solution in the secondary cleaning solution tank 38 is pumped into the secondary reverse osmosis membrane module 30, and the cyclic soaking is performed alternately, and the cyclic soaking is performed for 1h, and the alternate operation is performed, so that the pH of the chemical cleaning solution is not changed any more.
The solution prepared in the chemical cleaning process is citric acid, phosphoric acid or nitric acid with a certain concentration, when the solution reacts with pollutants on the surface of the membrane, the pH value is increased until the reaction is finished, and the pH value is not changed any more, so that the pH value is tested every 1h in the cleaning process until the pH value is not changed any more, namely the cleaning end point, and the membrane system is washed clean to be neutral by reverse osmosis produced water.
Example 2
The embodiment provides a process method of a system for recycling phosphoric acid by using the wastewater from the iron phosphate production in embodiment 1, which specifically comprises the following steps:
s1: the iron phosphate production wastewater in the raw water tank is washing water, mother liquor or mixed liquor of washing water and mother liquor, the concentration of phosphoric acid is 1% -16%, and the incoming water temperature is 40-50 ℃;
s2: removing large-particle impurities and suspended matters in the production wastewater by adopting an ultrafiltration filter unit, wherein the pore diameter of the membrane is 0.02-0.1 micrometer, the dead end total filtration is carried out, and the recovery rate is 99% -99.5%;
s3: and purifying the primary phosphoric acid, namely intercepting cations in the production wastewater by adopting a primary nanofiltration filter unit, and purifying the phosphoric acid. The nanofiltration membrane is an acid-resistant nanofiltration membrane, the removal rate of cations such as iron, manganese and the like is more than 90%, the recovery rate is 80-85%, and concentrated water returns to the original water tank;
s4: and (3) concentrating the primary phosphoric acid, namely concentrating the primary nanofiltration produced water in the step S3 by adopting a primary reverse osmosis unit, and improving the concentration of the phosphoric acid. An acid-resistant reverse osmosis membrane is adopted, and the recovery rate is 50% -80%; the concentration multiple of phosphoric acid is 2-5 times. And (5) recycling produced water, and enabling concentrated water to enter a first-stage reverse osmosis concentrated water tank.
S5: purifying secondary phosphoric acid, enriching cations such as iron and manganese in the primary reverse osmosis concentrated water, increasing the concentration, setting a secondary nanofiltration unit for treating the reverse osmosis concentrated water, further removing the cations, and having a removal rate of more than 80 percent and a recovery rate of more than 70-85 percent for the cations such as iron and manganese. The nanofiltration product water enters a secondary phosphoric acid concentration process section, and the concentrated water returns to the original water tank.
S6: and concentrating the secondary phosphoric acid, adopting a secondary reverse osmosis unit, wherein the recovery rate is 50% -75%, the concentration multiple is 1.5-4 times, recycling the secondary reverse osmosis produced water, and recycling the concentrated water, namely the qualified phosphoric acid product, to the front-stage production process.
The above is only a preferred embodiment of the present utility model, and is not intended to limit the present utility model, but various modifications and variations can be made to the present utility model by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model should be included in the scope of the present utility model.
Claims (10)
1. The system for recycling phosphoric acid from waste water in iron phosphate production is characterized by comprising a raw water tank, an ultrafiltration filter unit, a first-stage nanofiltration filter unit, a first-stage reverse osmosis unit, a second-stage nanofiltration unit and a second-stage reverse osmosis unit, wherein:
the ultrafiltration unit comprises an ultrafiltration membrane component connected with the raw water tank, and the water producing end of the ultrafiltration membrane component is connected with an ultrafiltration water producing tank;
the primary nanofiltration unit comprises a primary nanofiltration membrane component connected with an ultrafiltration water production tank, and the water production end of the primary nanofiltration membrane component is connected with the primary nanofiltration water production tank;
the first-stage reverse osmosis unit comprises a first-stage reverse osmosis membrane component connected with a first-stage nanofiltration water production tank, the water production end of the first-stage reverse osmosis membrane component is connected with the first-stage reverse osmosis water production tank, and the concentrated water end of the first-stage reverse osmosis membrane component is connected with the first-stage reverse osmosis concentrated water tank;
the secondary nanofiltration unit comprises a secondary nanofiltration membrane component connected with the primary reverse osmosis concentrated water tank, and the water producing end of the secondary nanofiltration membrane component is connected with a secondary nanofiltration water producing tank;
the secondary reverse osmosis unit comprises a secondary reverse osmosis membrane assembly connected with a secondary nanofiltration water production tank, the water production end of the secondary reverse osmosis membrane assembly is connected with the secondary reverse osmosis water production tank, and the dense water end of the secondary reverse osmosis membrane assembly is connected with the secondary reverse osmosis dense water tank.
2. The system of claim 1, wherein the ultrafiltration filter unit further comprises an ultrafiltration wash tank connected to the water inlet end, the concentrate end of the ultrafiltration membrane module.
3. The system of claim 2, wherein the ultrafiltration wash tank is connected to a water producing end of the primary reverse osmosis membrane module and a water producing end of the secondary reverse osmosis membrane module.
4. The system of claim 2, wherein the ultrafiltration wash tank is connected to the water producing end of the ultrafiltration membrane module by an ultrafiltration backwash pump, tubing.
5. The system of claim 1, wherein the primary nanofiltration unit further comprises a primary nanofiltration wash tank connected to the water inlet end, the concentrate end of the primary nanofiltration membrane module.
6. The system of claim 1, wherein the primary reverse osmosis unit further comprises a primary reverse osmosis purge tank connected to the water inlet end, the concentrate end of the primary reverse osmosis membrane module.
7. The system of claim 1, further comprising a secondary purge tank; the secondary cleaning water tank is connected with the water inlet end and the concentrated water end of the secondary nanofiltration membrane component; the second-stage cleaning water tank is connected with the water inlet end and the concentrated water end of the second-stage reverse osmosis membrane component.
8. The system of claim 1, wherein the concentrate end of the primary nanofiltration membrane module is connected to a raw water tank; the concentrated water end of the secondary nanofiltration membrane component is connected with a raw water tank.
9. The system of any one of claims 1-8, wherein:
the raw water tank is connected with an ultrafiltration membrane component through an ultrafiltration water inlet pump and a pipeline;
the ultrafiltration water producing tank is connected with the primary nanofiltration membrane component through a primary nanofiltration water inlet pump and a pipeline;
the first-stage nanofiltration product water tank is connected with a first-stage reverse osmosis membrane assembly through a first-stage reverse osmosis water inlet pump and a pipeline;
the first-stage reverse osmosis concentrated water tank is connected with a second-stage nanofiltration membrane component through a second-stage nanofiltration water inlet pump and a pipeline;
the secondary nanofiltration water production tank is connected with the secondary reverse osmosis membrane assembly through a secondary reverse osmosis water inlet pump and a pipeline.
10. The system of claim 9, wherein a valve is disposed on the conduit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202321664088.8U CN219991386U (en) | 2023-06-28 | 2023-06-28 | System for phosphoric acid is retrieved to iron phosphate waste water |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202321664088.8U CN219991386U (en) | 2023-06-28 | 2023-06-28 | System for phosphoric acid is retrieved to iron phosphate waste water |
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| CN202321664088.8U Active CN219991386U (en) | 2023-06-28 | 2023-06-28 | System for phosphoric acid is retrieved to iron phosphate waste water |
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