CN115676856B - Method and system for extracting lithium from salt lake - Google Patents
Method and system for extracting lithium from salt lake Download PDFInfo
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- CN115676856B CN115676856B CN202211364848.3A CN202211364848A CN115676856B CN 115676856 B CN115676856 B CN 115676856B CN 202211364848 A CN202211364848 A CN 202211364848A CN 115676856 B CN115676856 B CN 115676856B
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- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 title claims abstract description 100
- 229910052744 lithium Inorganic materials 0.000 title claims abstract description 99
- 238000000034 method Methods 0.000 title claims abstract description 69
- 238000001728 nano-filtration Methods 0.000 claims abstract description 381
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 281
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 claims abstract description 115
- 239000012267 brine Substances 0.000 claims abstract description 107
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 claims abstract description 90
- 238000001556 precipitation Methods 0.000 claims abstract description 62
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 claims abstract description 58
- 229910052796 boron Inorganic materials 0.000 claims abstract description 58
- 238000002425 crystallisation Methods 0.000 claims abstract description 55
- 229910001416 lithium ion Inorganic materials 0.000 claims abstract description 53
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 claims abstract description 52
- 229910052808 lithium carbonate Inorganic materials 0.000 claims abstract description 52
- 230000008025 crystallization Effects 0.000 claims abstract description 51
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 claims abstract description 44
- 239000012452 mother liquor Substances 0.000 claims abstract description 43
- 238000000502 dialysis Methods 0.000 claims abstract description 42
- 238000001704 evaporation Methods 0.000 claims abstract description 42
- 238000001914 filtration Methods 0.000 claims abstract description 40
- 230000008020 evaporation Effects 0.000 claims abstract description 38
- 238000001179 sorption measurement Methods 0.000 claims abstract description 33
- 238000003860 storage Methods 0.000 claims abstract description 23
- 238000002156 mixing Methods 0.000 claims abstract description 13
- 238000010992 reflux Methods 0.000 claims abstract description 13
- 239000010413 mother solution Substances 0.000 claims abstract description 12
- 238000000926 separation method Methods 0.000 claims description 38
- 239000000047 product Substances 0.000 claims description 34
- 150000001450 anions Chemical class 0.000 claims description 31
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 claims description 28
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 claims description 25
- 239000012141 concentrate Substances 0.000 claims description 22
- 238000000605 extraction Methods 0.000 claims description 22
- 238000011084 recovery Methods 0.000 claims description 21
- 239000011777 magnesium Substances 0.000 claims description 17
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims description 16
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 claims description 16
- 239000011575 calcium Substances 0.000 claims description 16
- 229910052749 magnesium Inorganic materials 0.000 claims description 16
- 229910052791 calcium Inorganic materials 0.000 claims description 15
- 150000003839 salts Chemical class 0.000 claims description 15
- 239000007787 solid Substances 0.000 claims description 13
- BVKZGUZCCUSVTD-UHFFFAOYSA-M Bicarbonate Chemical compound OC([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-M 0.000 claims description 12
- 239000007864 aqueous solution Substances 0.000 claims description 11
- 239000002244 precipitate Substances 0.000 claims description 11
- 229920005989 resin Polymers 0.000 claims description 11
- 239000011347 resin Substances 0.000 claims description 11
- 239000003513 alkali Substances 0.000 claims description 9
- 239000006228 supernatant Substances 0.000 claims description 9
- 239000000084 colloidal system Substances 0.000 claims description 6
- 239000012528 membrane Substances 0.000 description 25
- 150000001768 cations Chemical class 0.000 description 14
- GCICAPWZNUIIDV-UHFFFAOYSA-N lithium magnesium Chemical compound [Li].[Mg] GCICAPWZNUIIDV-UHFFFAOYSA-N 0.000 description 12
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 9
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 8
- 229910001414 potassium ion Inorganic materials 0.000 description 8
- 229910001415 sodium ion Inorganic materials 0.000 description 8
- 239000000243 solution Substances 0.000 description 8
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical group [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 7
- JLVVSXFLKOJNIY-UHFFFAOYSA-N Magnesium ion Chemical compound [Mg+2] JLVVSXFLKOJNIY-UHFFFAOYSA-N 0.000 description 7
- 229920001429 chelating resin Polymers 0.000 description 7
- 150000002500 ions Chemical class 0.000 description 7
- 229910001425 magnesium ion Inorganic materials 0.000 description 7
- 238000000108 ultra-filtration Methods 0.000 description 7
- WMFOQBRAJBCJND-UHFFFAOYSA-M Lithium hydroxide Chemical compound [Li+].[OH-] WMFOQBRAJBCJND-UHFFFAOYSA-M 0.000 description 6
- WCUXLLCKKVVCTQ-UHFFFAOYSA-M Potassium chloride Chemical compound [Cl-].[K+] WCUXLLCKKVVCTQ-UHFFFAOYSA-M 0.000 description 6
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 6
- 229910001424 calcium ion Inorganic materials 0.000 description 6
- 238000006243 chemical reaction Methods 0.000 description 6
- 238000004140 cleaning Methods 0.000 description 6
- 239000012535 impurity Substances 0.000 description 6
- 239000000203 mixture Substances 0.000 description 6
- BHPQYMZQTOCNFJ-UHFFFAOYSA-N Calcium cation Chemical compound [Ca+2] BHPQYMZQTOCNFJ-UHFFFAOYSA-N 0.000 description 5
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 5
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 5
- 235000011941 Tilia x europaea Nutrition 0.000 description 5
- BVKZGUZCCUSVTD-UHFFFAOYSA-N carbonic acid Chemical compound OC(O)=O BVKZGUZCCUSVTD-UHFFFAOYSA-N 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 239000004571 lime Substances 0.000 description 5
- 239000011591 potassium Substances 0.000 description 5
- 238000001223 reverse osmosis Methods 0.000 description 5
- 239000007790 solid phase Substances 0.000 description 5
- 238000010438 heat treatment Methods 0.000 description 4
- 239000007788 liquid Substances 0.000 description 4
- 229910003002 lithium salt Inorganic materials 0.000 description 4
- 159000000002 lithium salts Chemical class 0.000 description 4
- 239000008267 milk Substances 0.000 description 4
- 210000004080 milk Anatomy 0.000 description 4
- 235000013336 milk Nutrition 0.000 description 4
- 239000011780 sodium chloride Substances 0.000 description 4
- 229910000019 calcium carbonate Inorganic materials 0.000 description 3
- 125000005587 carbonate group Chemical group 0.000 description 3
- 150000003841 chloride salts Chemical class 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 229910052700 potassium Inorganic materials 0.000 description 3
- 239000001103 potassium chloride Substances 0.000 description 3
- 235000011164 potassium chloride Nutrition 0.000 description 3
- 230000001376 precipitating effect Effects 0.000 description 3
- 238000000746 purification Methods 0.000 description 3
- 238000004064 recycling Methods 0.000 description 3
- 239000011435 rock Substances 0.000 description 3
- 239000012266 salt solution Substances 0.000 description 3
- 229910000029 sodium carbonate Inorganic materials 0.000 description 3
- ODINCKMPIJJUCX-UHFFFAOYSA-N Calcium oxide Chemical compound [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 2
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 description 2
- ZFXVRMSLJDYJCH-UHFFFAOYSA-N calcium magnesium Chemical compound [Mg].[Ca] ZFXVRMSLJDYJCH-UHFFFAOYSA-N 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 238000005265 energy consumption Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000000887 hydrating effect Effects 0.000 description 2
- KWGKDLIKAYFUFQ-UHFFFAOYSA-M lithium chloride Chemical compound [Li+].[Cl-] KWGKDLIKAYFUFQ-UHFFFAOYSA-M 0.000 description 2
- VTHJTEIRLNZDEV-UHFFFAOYSA-L magnesium dihydroxide Chemical group [OH-].[OH-].[Mg+2] VTHJTEIRLNZDEV-UHFFFAOYSA-L 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 1
- 239000003463 adsorbent Substances 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 1
- 239000000920 calcium hydroxide Substances 0.000 description 1
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 1
- USOPFYZPGZGBEB-UHFFFAOYSA-N calcium lithium Chemical compound [Li].[Ca] USOPFYZPGZGBEB-UHFFFAOYSA-N 0.000 description 1
- 239000000292 calcium oxide Substances 0.000 description 1
- 235000012255 calcium oxide Nutrition 0.000 description 1
- 238000003763 carbonization Methods 0.000 description 1
- 239000006071 cream Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- GDVKFRBCXAPAQJ-UHFFFAOYSA-A dialuminum;hexamagnesium;carbonate;hexadecahydroxide Chemical compound [OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[Mg+2].[Mg+2].[Mg+2].[Mg+2].[Mg+2].[Mg+2].[Al+3].[Al+3].[O-]C([O-])=O GDVKFRBCXAPAQJ-UHFFFAOYSA-A 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 239000010459 dolomite Substances 0.000 description 1
- 229910000514 dolomite Inorganic materials 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000000909 electrodialysis Methods 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 239000013505 freshwater Substances 0.000 description 1
- 239000010440 gypsum Substances 0.000 description 1
- 229910052602 gypsum Inorganic materials 0.000 description 1
- 229960001545 hydrotalcite Drugs 0.000 description 1
- 229910001701 hydrotalcite Inorganic materials 0.000 description 1
- 230000008676 import Effects 0.000 description 1
- 238000002386 leaching Methods 0.000 description 1
- VVNXEADCOVSAER-UHFFFAOYSA-N lithium sodium Chemical compound [Li].[Na] VVNXEADCOVSAER-UHFFFAOYSA-N 0.000 description 1
- DHRRIBDTHFBPNG-UHFFFAOYSA-L magnesium dichloride hexahydrate Chemical compound O.O.O.O.O.O.[Mg+2].[Cl-].[Cl-] DHRRIBDTHFBPNG-UHFFFAOYSA-L 0.000 description 1
- 239000000347 magnesium hydroxide Substances 0.000 description 1
- 229910001862 magnesium hydroxide Inorganic materials 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910021645 metal ion Inorganic materials 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000011045 prefiltration Methods 0.000 description 1
- 238000002203 pretreatment Methods 0.000 description 1
- NGVDGCNFYWLIFO-UHFFFAOYSA-N pyridoxal 5'-phosphate Chemical compound CC1=NC=C(COP(O)(O)=O)C(C=O)=C1O NGVDGCNFYWLIFO-UHFFFAOYSA-N 0.000 description 1
- 230000003134 recirculating effect Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 235000017557 sodium bicarbonate Nutrition 0.000 description 1
- 229910000030 sodium bicarbonate Inorganic materials 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 230000002194 synthesizing effect Effects 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
- 239000002918 waste heat Substances 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Abstract
The invention relates to a method and a system for extracting lithium from a salt lake, wherein the method for extracting lithium from the salt lake comprises the following steps: pretreating raw brine; pre-nanofiltration of the pretreated raw brine, wherein the pre-nanofiltration comprises at least two nanofiltration processes; performing primary evaporation crystallization on the water produced after the pre-nanofiltration to obtain mother solution containing lithium ions; performing multi-stage nanofiltration comprising at least three nanofiltration processes on the mother liquor, and performing secondary evaporation crystallization on produced water; performing secondary dialysis nanofiltration on part of concentrated water after the multistage nanofiltration, and refluxing produced water to the multistage nanofiltration; performing first boron removal adsorption on the mother solution after secondary evaporation crystallization to obtain produced water for forming lithium carbonate precipitation; mixing part of the concentrated water after the pre-nanofiltration with the concentrated water after the secondary dialysis nanofiltration to carry out carbonate storage and filtration, refluxing the produced water to pretreatment, carrying out second boron removal adsorption on the concentrated water, and mixing the produced water after the second boron removal adsorption with the produced water after the first boron removal adsorption to form lithium carbonate precipitation.
Description
Technical Field
The invention relates to the technical field of salt lake brine lithium extraction, in particular to a salt lake lithium extraction method and system.
Background
The global lithium resource distribution is concentrated, the lithium storage in the domestic salt lake is rich, and lithium is taken as white petroleum in the new era and is widely applied to rechargeable batteries in the fields of mobile phones, notebook computers, electric vehicles and the like. With the development of new energy fields in the whole society, the strategic economic value of lithium resources is further improved.
From a resource morphology perspective, global lithium resource supply sources mainly include hard rock ore (including pegmatite, dolomite, dan Yingmai, and sedimentary mud), salt lake brine, underground brine, geothermal brine, and the like. Salt lake brine is mainly concentrated in Argentina, chilean, the United states and the Qinghai-Tibet area of China, and the salt lake brine has more cost advantage than hard rock ore lithium extraction, so that the salt lake brine is a main way for producing world lithium products.
The salt lake brine contains a large amount of elements such as sodium, potassium, boron, magnesium and the like besides lithium, so that impurity ions are required to be separated and purified in the lithium extraction process, and the technology of extracting lithium from the salt lake is different due to different salt compositions of the salt lake at home and abroad, wherein the technology is most difficult when magnesium and lithium are separated. Compared with the extraction of lithium from hard rock ore, the extraction of lithium from salt lake brine has more cost advantage. The salt lake lithium extraction is generally carried out by extracting from residual brine after potassium element extraction, extracting lithium ions or lithium chloride solution from old brine after potassium extraction by sun-drying natural evaporation or evaporator concentration, and then preparing lithium carbonate product by adding carbonate.
Compared with abroad, most of salt lakes in China are mainly concentrated in Qinghai and Tibet, wherein the Qinghai salt lake brine has large resource reserve and good exploitation environment, but has high magnesium-lithium ratio, high sodium-lithium ratio and high separation difficulty, so that the lithium loss rate in the lithium extraction process is high, the development cost is high and the comprehensive exploitation and utilization degree is low. The Tibetan salt lake belongs to carbonate type salt mine, and has better quality, and the magnesium-lithium ratio is lower, for example, the Zaboje salt lake is positioned on a plateau with an altitude 4400 meters although the magnesium-lithium ratio is as low as 0.019, the natural environment condition is poorer, and the exploitation difficulty is higher.
CN103074502a discloses a salt lake brine treatment method for separating lithium from salt lake brine with high magnesium-to-lithium ratio, comprising the steps of: evaporating the salt lake brine in a multi-stage salt field to obtain first old brine; sulfur removal: lime cream is added into the first old brine to separate out gypsum, so as to obtain second old brine; evaporating the second old brine in a salt field, and separating out bischofite to obtain third old brine; diluting the third old brine, and sending the third old brine into a nanofiltration membrane device for nanofiltration treatment to obtain lithium-rich produced water and lithium-poor concentrated water; and (3) delivering the produced water in the previous step into a reverse osmosis membrane device for reverse osmosis treatment to obtain reverse osmosis concentrated water and fresh water.
CN105177288A discloses a method for preparing lithium hydroxide by utilizing salt lake brine with high magnesium-lithium ratio, which specifically comprises the following steps: the method comprises the steps of taking salt lake brine with high magnesium-lithium ratio as a raw material, adding a certain amount of soluble trivalent metal salt, reducing the magnesium-lithium ratio in the salt lake brine with high magnesium-lithium ratio by synthesizing a magnesium-based layered functional material, separating magnesium and lithium in the salt lake brine with high magnesium-lithium ratio, removing magnesium in the brine, and preparing lithium hydroxide by using lithium-rich hydrotalcite mother liquor.
CN101508450 discloses a method for extracting lithium salt from salt lake brine with low magnesium-lithium ratio by calcium cycle solid phase conversion method, comprising: concentrating brine: evaporating and concentrating salt lake brine with low magnesium-lithium ratio; lime milk magnesium removal: mixing the mother liquor after concentrating and concentrating the brine with lime milk, performing solid phase conversion reaction, and removing magnesium in the mother liquor in a magnesium hydroxide form through solid phase conversion from calcium hydroxide to magnesium hydroxide; separation of calcium from lithium carbonate: mixing the magnesium-removed calcium-lithium solution with solid lithium carbonate, performing solid phase conversion reaction, and separating and removing calcium in the solution in a calcium carbonate form through solid phase conversion of the lithium carbonate to calcium carbonate to obtain a purified lithium salt solution; concentrating lithium salt, precipitating crystalline lithium carbonate and calcium carbonate, thermally decomposing and hydrating: evaporating and concentrating the purified lithium salt solution obtained in the step of separating calcium from lithium carbonate; adding sodium carbonate to react with the sodium carbonate, and precipitating crystalline lithium carbonate; and (3) carrying out thermal decomposition on the calcium carbonate obtained in the step of separating calcium from the lithium carbonate to obtain quicklime, hydrating to obtain lime milk, and returning to the lime milk demagging step for demagging.
A plurality of processes are developed aiming at the salt lake brine lithium extraction technology, and each process has advantages in the aspects of cost, operation process, selectivity, energy consumption, recovery rate and the like, but has no small limitation. For example, the precipitation method has long process flow, large material consumption and complicated operation, and is only suitable for salt lakes with low magnesium-lithium ratio. The adsorption method is poor in fluidity and adsorptivity because the adsorbents are mostly powder, and is liable to cause the decrease of adsorption performance. Membrane pollution is easy to occur during separation by a nanofiltration membrane method, so that the separation efficiency is reduced, and most of aluminum membranes with excellent performances are mostly dependent on import, so that the cost is extremely high. Electrodialysis membranes are difficult to separate monovalent cations, are easily contaminated, and are costly. The extraction method has long process flow, is easy to cause equipment corrosion, and the extractant generally has physicochemical properties of water solubility, flammability, volatility and the like. The solar cell and carbonization method is easily limited by geographical condition factors, has low replicability, is difficult to popularize in a large area, and has low grade of actually produced lithium products. The calcination leaching method has complex flow, easy equipment corrosion and high energy consumption.
Therefore, in order to solve at least one or more technical problems in the prior art, it is needed to provide a process and a system for extracting lithium from salt lake brine, in particular to a method for purifying lithium ions from salt lake brine in high altitude areas such as Tibet and the like.
Furthermore, there are differences in one aspect due to understanding to those skilled in the art; on the other hand, since the applicant has studied a lot of documents and patents while making the present invention, the text is not limited to details and contents of all but it is by no means the present invention does not have these prior art features, but the present invention has all the prior art features, and the applicant remains in the background art to which the right of the related prior art is added.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a method and a system for extracting lithium from a salt lake, which aim to solve at least one or more technical problems in the prior art.
In order to achieve the above object, the present invention provides a method for extracting lithium from a salt lake, comprising:
pre-nanofiltration of the pretreated raw brine, wherein the pre-nanofiltration comprises at least two nanofiltration processes;
performing primary evaporation crystallization on the pre-nanofiltration produced water to obtain mother liquor containing lithium ions;
subjecting the mother liquor to a multi-stage nanofiltration comprising at least three nanofiltration processes;
performing secondary evaporation crystallization on the water produced after the multistage nanofiltration;
performing secondary dialysis nanofiltration on part of concentrated water after the multi-stage nanofiltration, and refluxing the produced water after the secondary dialysis nanofiltration to the multi-stage nanofiltration;
Performing first boron removal adsorption on the mother solution after secondary evaporation crystallization to obtain produced water for forming lithium carbonate precipitation;
mixing part of concentrated water after pre-nanofiltration with concentrated water after secondary dialysis nanofiltration to carry out carbonate storage and filtration, and enabling the produced water after carbonate storage and filtration to flow back to pretreatment, and carrying out second boron removal adsorption on the concentrated water after carbonate storage and filtration, so that the produced water after second boron removal adsorption and the produced water after first boron removal adsorption are mixed to form lithium carbonate precipitation.
Preferably, the pre-nanofiltration of raw brine extracted from a salt lake, comprising at least two nanofiltration processes, further comprises:
pretreating raw brine extracted from a salt lake, and the pretreatment comprises:
carrying out heat exchange treatment on the raw brine to heat the raw brine to a preset temperature;
performing multistage filtration on the heated raw brine to remove colloid and suspended matters in the raw brine;
and (3) carrying out resin adsorption on the raw brine subjected to the multistage filtration to reduce the hardness of calcium and magnesium in water.
Particularly, the raw brine after the salt lake water is concentrated in the pre-concentrated salt field has low temperature, so that the separation and the filtration treatment are inconvenient, and the raw brine needs to be subjected to a certain temperature rise treatment. Further, impurities such as colloid and suspended matters in water are filtered through a filter, an ultrafiltration membrane device and the like, and the water hardness is reduced through resin adsorption, so that subsequent nanofiltration separation treatment of anions and cations in water is facilitated, and the grade of a later-stage lithium ion purification product is improved.
Preferably, the pre-nanofiltration of the pretreated raw brine, comprising at least two nanofiltration processes, comprises:
carrying out first-stage nanofiltration on the pretreated raw brine to carry out first-stage separation on chloride ions, carbonate radicals and sulfate radicals in the raw brine, wherein concentrated water subjected to the first-stage nanofiltration flows back to a salt lake;
and carrying out second-stage nanofiltration on the first-stage nanofiltration produced water to carry out second separation on chloride ions, carbonate and sulfate radicals, wherein the produced water of the second-stage nanofiltration flows to primary evaporation crystallization, and the concentrated water of the second-stage nanofiltration flows to carbonate to be back to storage filtration. Particularly, as the concentrated water of the first-stage nanofiltration has high carbonate and sulfate radical contents (relatively small amount of chloride ions), the concentrated water needs to be refluxed to the salt lake, and waste heat can be recovered through heat exchange equipment in the process so as to improve the energy utilization rate. Furthermore, the pH of the water produced by the first-stage nanofiltration is lower than that of the water produced by the first-stage nanofiltration due to the nature of the nanofiltration membrane, so that the water produced contains part of bicarbonate, and the bicarbonate can be converted into carbonate through alkali liquor such as sodium hydroxide to improve the corresponding concentration or content, so that chloride ions and carbonate are further separated through the second-stage nanofiltration, and the separation ratio or effect is improved. On the other hand, based on the difference of melting boiling points among potassium ions, sodium ions and lithium ions in the secondary nanofiltration produced water, the potassium ions and the sodium ions in the water are separated out into sodium chloride and potassium chloride crystals by primary evaporation crystallization so as to be removed, and the lithium ions which are not separated out are further concentrated.
Preferably, performing a multistage nanofiltration of the mother liquor comprising at least three nanofiltration processes comprises:
carrying out third nanofiltration on the mother solution after primary evaporation crystallization to carry out third separation on chloride ions, carbonate radicals and sulfate radicals, wherein concentrated water of the third nanofiltration flows to the second dialysis nanofiltration;
performing fourth-stage nanofiltration on the third-stage nanofiltration produced water to perform fourth separation on chloride ions, carbonate and sulfate, wherein concentrated water of the fourth-stage nanofiltration flows to the second-stage dialysis nanofiltration;
and carrying out fifth-stage nanofiltration on the fourth-stage nanofiltration product water to carry out fifth separation on chloride ions, carbonate and sulfate radicals, wherein concentrated water of the fifth-stage nanofiltration product water flows to a middle salt pan, and the fifth-stage nanofiltration product water flows to secondary evaporation crystallization. Particularly, after primary evaporation and crystallization in the early stage, the concentration of lithium ions is increased, so that lithium carbonate is not precipitated in water produced during five-stage nanofiltration, the concentration of carbonate in water is greatly reduced through three-stage nanofiltration, bicarbonate in water obtained through four-stage nanofiltration is converted into lithium carbonate, and chloride ions, lithium ions and carbonate in water are separated for multiple times through three-stage nanofiltration, four-stage nanofiltration and five-stage nanofiltration, so that the separation degree of lithium ions and carbonate is improved.
Preferably, the second-stage dialysis nanofiltration of the part of the concentrated water after the multistage nanofiltration comprises:
mixing the concentrated water of the third level nanofiltration with the concentrated water of the fourth level nanofiltration, sequentially carrying out first-level dialysis nanofiltration and second-level dialysis nanofiltration on the mixed concentrated water flow to separate and recycle lithium ions and carbonate radicals in the mixed concentrated water flow,
wherein, the produced water after the second-stage dialysis nanofiltration is provided to the water inlet end of the fourth-stage nanofiltration. In particular, the three-stage nanofiltration product water and the four-stage nanofiltration concentrated water have relatively high carbonate content, so that the three-stage nanofiltration product water and the four-stage nanofiltration concentrated water are required to be further separated and treated through the two-stage dialysis nanofiltration so as to reflux lithium ions in the three-stage nanofiltration product water and the four-stage nanofiltration concentrated water to the water inlet end of the fourth-stage nanofiltration product water, thereby improving the purification concentration and grade of the lithium ions in the later stage. Particularly, part of the concentrated water after the multi-stage nanofiltration is still not separated from lithium ions and carbonate, so that the lithium ions and carbonate in the concentrated water are required to be separated and recovered again through the secondary dialysis nanofiltration.
Preferably, the method further comprises, before the second stage nanofiltration of the first stage nanofiltration product water:
and adjusting the PH of the first-stage nanofiltration produced water by alkali liquor so as to convert bicarbonate in the first-stage nanofiltration produced water into carbonate.
Preferably, the method further comprises, before performing the fourth stage nanofiltration on the third stage nanofiltration product water:
And adjusting the PH of the third-stage nanofiltration produced water by alkali liquor so as to convert bicarbonate in the third-stage nanofiltration produced water into carbonate.
Preferably, mixing the second boron-removed adsorbed product water with the first boron-removed adsorbed product water to form lithium carbonate precipitate further comprises:
filtering the supernatant after forming lithium carbonate precipitation to form lithium precipitation mother liquor;
carrying out lithium precipitation nanofiltration on the lithium precipitation mother solution to separate and recycle lithium ions and carbonate radicals in the lithium precipitation mother solution;
refluxing the precipitated lithium nanofiltration product water to form a lithium carbonate precipitate; and
and enabling the concentrated water after lithium precipitation nanofiltration to flow to carbonate radicals for storage and filtration.
Preferably, refluxing the carbonate-containing filtered produced water to the pretreatment comprises:
and (3) enabling the produced water after the carbonate storage filtration to flow back to the water inlet end of the multi-stage filtration so as to be mixed with the original brine after temperature rise to carry out the multi-stage filtration.
Preferably, the present invention provides a salt lake lithium extraction system for implementing the salt lake lithium extraction method of the present invention, the system comprising:
the pretreatment unit is used for pretreating raw brine extracted from the salt lake;
the pre-nanofiltration unit is used for carrying out pre-nanofiltration comprising at least two nanofiltration processes on the pretreated raw brine;
The first evaporation crystallization device is used for performing primary evaporation crystallization on the pre-nanofiltration produced water so as to obtain mother liquor containing lithium ions;
a multi-stage nanofiltration unit for performing multi-stage nanofiltration comprising at least three nanofiltration processes on the mother liquor;
the second evaporation crystallization device is used for performing secondary evaporation crystallization on the produced water after the multistage nanofiltration;
the two-stage dialysis nanofiltration unit is used for carrying out secondary dialysis nanofiltration on part of concentrated water after the multistage nanofiltration and providing produced water to the multistage nanofiltration unit;
the first boron removing device is used for carrying out first boron removing adsorption on the mother solution after the secondary evaporation crystallization to obtain produced water for forming lithium carbonate precipitation;
the back storage and filtration unit is used for carrying out carbonate concentration treatment on part of concentrated water provided by the pre-nanofiltration unit and the concentrated water provided by the two-stage dialysis nanofiltration unit and providing produced water for back flow to the pretreatment unit;
and the second boron removing device is used for carrying out second boron removing adsorption on the concentrated water discharged by the recovery nanofiltration unit so as to provide produced water which is used for being mixed with the produced water after the first boron removing adsorption to form lithium carbonate precipitation.
And the lithium precipitation nanofiltration unit is used for separating lithium ions and carbonate ions in the supernatant liquid provided by the step of lithium carbonate precipitation and providing a step of refluxing produced water to form lithium carbonate precipitation.
The beneficial technical effects of the invention include: the method comprises the steps of firstly carrying out heating and impurity removal treatment on salt lake brine through pretreatment, then repeatedly separating monovalent anions and cations and divalent anions and cations in the brine through multistage nanofiltration for many times, separating out a large amount of sodium ions and potassium ions through primary evaporation crystallization in the process of many times of nanofiltration, and then carrying out secondary evaporation crystallization on nanofiltration produced water to separate out and remove the residual sodium ions and potassium ions so as to provide produced water containing relatively high lithium ions. On the other hand, the concentrate discharged from the whole multistage nanofiltration process contains a relatively high content of carbonate ions. Particularly, carbonate ions and lithium ions in brine are subjected to nanofiltration separation for a plurality of times, and are respectively combined, and finally the carbonate ions and the lithium ions which are respectively separated are mixed and reacted to form lithium carbonate, so that the extraction of the lithium ions is realized. For salt lake brine with high magnesium-lithium ratio, negative ions and positive ions, especially target ions, namely carbonate ions and lithium ions, in the brine are improved by repeated nanofiltration separation and circulating reflux of treatment products in part of process stages, so that the lithium ions in the brine can be recovered to the greatest extent, the waste of lithium resources is reduced, the quality of lithium products is improved, and the environmental pollution is reduced by recycling the reflux products, so that the cost is greatly saved compared with the traditional membrane separation process.
Drawings
Fig. 1 is a process flow chart of a salt lake lithium extraction method according to a preferred embodiment of the present invention.
List of reference numerals
1: a heat exchanger; 2: a multi-media filter; 3: self-cleaning the filter; 4: an ultrafiltration membrane device; 5: chelating resin towers; 6: a first stage nanofiltration device; 7: a secondary nanofiltration device; 8: a middle salt pan; 9: a first evaporative crystallization device; 10: a three-stage nanofiltration device; 11: a four-stage nanofiltration device; 12: a five-stage nanofiltration device; 13: a second evaporative crystallization device; 14: a first boron removal device; 15: a two-stage dialysis nanofiltration unit; 16: a back-receiving filter unit; 17: a second boron removal device; 18: a filtering device; 19: a lithium precipitation nanofiltration unit; 20: a lithium precipitation factory building; 21: salt lake; 100: raw brine; 200: producing water; 300: concentrated water; 400: a mother liquor; 500: a chloride salt; 600: lithium carbonate; 700: supernatant; 800: and precipitating lithium mother solution.
Detailed Description
The following detailed description refers to the accompanying drawings.
The invention provides a method for extracting lithium from a salt lake, and fig. 1 shows a process flow of the method for extracting lithium from the salt lake and a connection schematic diagram of a salt lake lithium extraction system corresponding to the method for extracting lithium from the salt lake. Particularly, the method for extracting lithium from the salt lake is particularly suitable for extracting lithium ions from salt lake brine in the altitude areas such as Tibet and the like.
Specifically, as shown in fig. 1, the method for extracting lithium from a salt lake of the present invention may include: raw brine 100 to be treated is provided from a salt lake 21. Further, the raw brine 100 enters a pretreatment unit for heating and impurity removal pretreatment.
According to a preferred embodiment, the raw brine 100 after the salt lake water is concentrated in the pre-concentrated salt pan is required to be preheated for the subsequent process treatment due to the low temperature (average-0.4 ℃). Specifically, the raw brine 100 is warmed to about 30 ℃ by the heat exchanger 1. In particular, in the present invention, the heat exchanger 1 may be a plate heat exchanger. The heat exchanger 1 may be, for example, a PLP 30-type plate heat exchanger.
According to a preferred embodiment, as shown in fig. 1, raw brine 100 heated by a heat exchanger 1 flows through a multi-medium filter 2, a self-cleaning filter 3 and an ultrafiltration membrane device 4 in sequence to remove colloid and suspended particles in the raw brine 100. In particular, the multimedia filter 2 may be, for example, a LF-SYS500 type multimedia filter. The self-cleaning filter 3 may be, for example, a JSY-AC20 type self-cleaning filter. The ultrafiltration membrane apparatus 4 may be, for example, a SUF-102NS type ultrafiltration membrane apparatus.
According to a preferred embodiment, as shown in fig. 1, raw brine 100 with colloid and suspended particulate matters filtered is fed into a chelating resin tower 5 to undergo displacement reaction with part of metal ions in the raw brine 100 through chelating resin, so as to reduce the calcium-magnesium hardness in the raw brine 100. Further, the raw brine 100 enters a subsequent pre-nanofiltration unit for further filtration and separation treatment. The chelating resin column 5 may be, for example, an RTF type chelating resin column.
According to a preferred embodiment, the effluent requirement after pretreatment is for example Mg 2+ The content is less than 20mg/L. SDI is less than 3. Turbidity is less than 0.1NTU. The discharge pressure is not less than 0.4MPaG.
According to a preferred embodiment, the requirements for the resin include, for example: the absolute value of the difference between the effective particle diameters of the resins is not more than 0.1mm. The wet true density difference of the resin is more than or equal to 0.15g/ml. The temperature resistance of the resin is more than or equal to 75 ℃, and the pressure resistance is more than or equal to 0.80MPa.
According to a preferred embodiment, as shown in fig. 1, the pre-nanofiltration unit may comprise a primary nanofiltration device 6 and a secondary nanofiltration device 7 connected in sequence in the present invention. Specifically, the raw brine 100 first enters the primary nanofiltration device 6, so that monovalent chloride ions and divalent carbonate and sulfate radicals in the raw brine 100 are separated by the primary nanofiltration device 6. In particular, the retention rate of sulfate radical and carbonate radical is about 97% and about 85% respectively through the first-stage nanofiltration device 6.
Further, as shown in fig. 1, the raw brine 100 is filtered and separated by the first-stage nanofiltration device 6, and the discharged concentrated water 300 (containing a large amount of carbonate and sulfate) is recycled by a heat exchange device (e.g. a plate heat exchanger) to be returned to the salt lake 21 to be mixed with the salt lake water in the salt lake 21 so as to circulate the pretreatment and the first-stage nanofiltration process.
On the other hand, the raw brine 100 is filtered and separated by the first-stage nanofiltration device 6, and the discharged produced water 200 enters the second-stage nanofiltration device 7 for further filtration and separation. Specifically, based on the nature of nanofiltration membranes, the PH of the produced water 200 discharged from the primary nanofiltration device 6 after the primary brine 100 is treated may be lower than the previous value, i.e., the produced water 200 contains a small amount of bicarbonate and carbonate. Before the secondary nanofiltration water (the produced water 200 of the primary nanofiltration device 6) enters the secondary nanofiltration device 7, the PH of the water is adjusted by liquid alkali (for example, 20% sodium hydroxide solution), namely, bicarbonate is converted into carbonate, and then the secondary nanofiltration water (the produced water 200 of the primary nanofiltration device 6) is conveyed to the secondary nanofiltration device 7 for treatment.
According to a preferred embodiment, as shown in fig. 1, the produced water 200 of the primary nanofiltration device 6 enters the secondary nanofiltration device 7 for further filtration and separation treatment after the pH value of the produced water is regulated by liquid alkali, so as to further separate monovalent chloride ions and divalent carbonate radicals.
According to a preferred embodiment, the prefilter unit discharge requirements are, for example: the sulfate radical content is less than 0.05g/L, and the carbonate radical content is less than 0.3g/L. The recovery rate of lithium ions is not less than 36%. The outlet water pressure is not less than 0.4MpaG. The water yield at the outlet is not lower than 456m3/h.
According to a preferred embodiment, as shown in fig. 1, the produced water 200 (which contains only small amounts of divalent anions: sulfate and carbonate and large amounts of monovalent cations: chloride) discharged from the secondary nanofiltration device 7 flows into the intermediate salt pan 8 and further enters the first crystallization evaporation device 9 for evaporation crystallization treatment. Specifically, the produced water 200 discharged from the secondary nanofiltration device 7 enters the first crystallization evaporation device 9 to be crystallized to separate out chloride salt 500 (sodium chloride and potassium chloride). Further, when the chloride 500 is precipitated, lithium ions are not precipitated yet, and the produced water 200 is evaporated and crystallized to discharge the mother liquor 400 containing lithium ions. The mother liquor 400 with low temperature (about 8 ℃) after evaporation and crystallization enters a multi-stage nanofiltration system for further filtration and separation treatment. In particular, the mother liquor 400 is concentrated in lithium ions after evaporation and crystallization, and also in sulfate and carbonate ions.
On the other hand, as shown in fig. 1, the concentrated water 300 (containing carbonate) discharged from the secondary nanofiltration device 7 enters the storage and filtration unit 16 for subsequent treatment. Specifically, as shown in fig. 1, the recovery nanofiltration unit 16 further concentrates carbonate in the concentrated water 300 discharged from the secondary nanofiltration device 7. Further, the produced water 200 discharged from the recovery nanofiltration unit 16 is returned to the pretreatment unit, and specifically to the water inlet end of the multimedia filter 2.
Further, as shown in fig. 1, the multi-stage nanofiltration unit of the present invention may include a three-stage nanofiltration device 10, a four-stage nanofiltration device 11, and a five-stage nanofiltration device 12. Specifically, the mother liquor 400 discharged from the first crystallization and evaporation device 9 is subjected to heating treatment and then enters the three-stage nanofiltration device 10, so that monovalent chloride ions, divalent carbonate radicals and sulfate radicals in the incoming water (mother liquor 400) are filtered and separated by the three-stage nanofiltration device 10.
According to a preferred embodiment, as shown in fig. 1, the produced water 200 discharged from the three-stage nanofiltration device 10 enters the four-stage nanofiltration device 11 for further filtration and separation treatment. Specifically, before the secondary water from the secondary nanofiltration (the produced water 200 discharged from the tertiary nanofiltration device 10) enters the secondary nanofiltration device 11, the PH of the secondary nanofiltration device is adjusted by liquid alkali so as to convert bicarbonate in the secondary nanofiltration device into carbonate, namely sodium bicarbonate into sodium carbonate. Further, the secondary water from the four-stage nanofiltration (produced water 200 discharged from the three-stage nanofiltration device 10) enters the four-stage nanofiltration device 11 to further separate monovalent chloride ions from divalent carbonate ions therein.
According to a preferred embodiment, as shown in fig. 1, the five-stage nanofiltration incoming water (produced water 200 discharged from the four-stage nanofiltration device 11) enters the five-stage nanofiltration device 12 to further separate monovalent chloride ions and divalent carbonate groups.
According to a preferred embodiment, as shown in fig. 1, the concentrate 300 discharged from the five-stage nanofiltration device 12 is returned to the intermediate salt pan 8. The produced water 200 discharged from the five-stage nanofiltration device 12 enters the second evaporation crystallization device 13, and is crystallized to separate out chloride salt 500 (sodium chloride and potassium chloride) in sequence. At this time, the produced water 200 is evaporated and crystallized by the second evaporation and crystallization device 13, and then the mother liquor 400 containing lithium ions is discharged. Further, the mother liquor 400 enters the first boron removal device 14 for further processing.
According to a preferred embodiment, the following table shows the elemental composition (in g/L) of the feed water to the multi-stage nanofiltration unit in an alternative embodiment.
In particular, since the concentration of lithium ions increases after the treatment by the first evaporative crystallization device 9 in the early stage and lithium carbonate is not precipitated when the water produced by the five-stage nanofiltration passes through the second evaporative crystallization device 13, the mother liquor 400 needs to be treated by the three-stage nanofiltration device 10 to reduce the concentration of carbonate in the water produced by the nanofiltration entering the second evaporative crystallization device 13 to be low (carbonate content < 100 mg/L).
According to a preferred embodiment, the discharge requirements of the five-stage nanofiltration device 12 are, for example: does not contain bicarbonate and carbonate. The boron content is less than 20mg/L. The recovery rate of lithium ions is not less than 95%. The pressure of the five-stage nanofiltration concentrated water, the five-stage nanofiltration produced water and the two-stage dialysis nanofiltration concentrated water is not less than 0.4MPaG.
According to a preferred embodiment, as shown in fig. 1, the mother liquor 400 discharged from the second evaporative crystallization device 13 enters the first boron removal device 14 to perform boron removal resin adsorption on the mother liquor 400. In particular, the mother liquor 400 entering the first boron removal device 14 at this time contains a large amount of lithium ions after multi-stage nanofiltration and multi-stage evaporative crystallization. Further, as shown in fig. 1, the mother liquor 400 treated by the first boron removal device 14 enters the lithium precipitation plant 20 for further treatment. Specifically, the mother liquor 400 (containing a large amount of lithium ions) forms lithium carbonate precipitate after precipitation treatment in the lithium precipitation plant 20.
According to a preferred embodiment, as shown in fig. 1, the mother liquor 400 is treated by the filtration device 18 to form a lithium precipitation mother liquor 800 after the supernatant 700 discharged from the lithium precipitation plant 20 after the lithium precipitation treatment, and the lithium precipitation mother liquor 800 enters the lithium precipitation nanofiltration unit 19 for further treatment.
Further, as shown in fig. 1, after the lithium precipitation mother liquor 800 is treated by the lithium precipitation nanofiltration unit 19, the discharged product water 200 is returned to the lithium precipitation plant 20 for reaction to form lithium carbonate precipitate. On the other hand, the concentrated water 300 discharged from the lithium precipitation nanofiltration unit 19 enters the back storage filtration unit 16 to further concentrate carbonate ions in the concentrated water 300 through the back storage filtration unit 16.
According to a preferred embodiment, as shown in fig. 1, the feed to the pre-nanofiltration unit comprises three streams of concentrate 300 from the primary nanofiltration unit 6, produced water 200 from the recovery nanofiltration unit 16 and flash condensate from the evaporative crystallisation unit (9, 13), respectively. In particular, the following table shows the elemental composition (in g/L) of the feed water to the pre-nanofiltration unit in an alternative embodiment.
According to a preferred embodiment, as shown in fig. 1, in the present invention, the recovery nanofiltration unit 16 is used to treat the concentrate 300 discharged from the secondary nanofiltration device 7, the two-stage dialysis nanofiltration unit 15 and the lithium precipitation nanofiltration unit 19. Specifically, the recovery nanofiltration unit 16 processes the three mixed concentrate streams for carbonate concentration. Further, the produced water 200 discharged from the recovery nanofiltration unit 16 is returned to the water inlet end of the multi-media filter 2, so that the part of the produced water 200 circulates the above-mentioned pretreatment, multi-stage nanofiltration, evaporative crystallization, boron removal adsorption, lithium precipitation nanofiltration treatment, etc. On the other hand, the concentrate 300 discharged from the recovery nanofiltration unit 16 enters the second boron removal apparatus 17 to perform boron removal resin adsorption. In particular, the concentrate 300 entering the second boron removal device 17 is a mixed concentrate stream obtained by multiple nanofiltration separations in the early stage, and contains a large amount of carbonate ions.
According to a preferred embodiment, the following table shows an alternative embodiment for recovering the elemental composition (in g/L) of the feed water to nanofiltration unit 16.
According to a preferred embodiment, the discharge requirements of the recovery nanofiltration unit 16 are for example: and the reclaimed filtered produced water and the reclaimed nanofiltration concentrated water do not contain bicarbonate. The carbonate content of the water produced by the back storage filtration is less than 0.5g/L. And (5) back-storing the filtered product water and recycling nanofiltration concentrated water, wherein the water outlet pressure is not less than 0.4MPaG.
According to a preferred embodiment, the first boron removal device 14 is used for performing boron removal adsorption treatment on the mother liquor 400 discharged from the second evaporative crystallization device 13. In particular, the mother liquor 500 entering the first boron removal apparatus 14 contains a significant amount of lithium ions. The second boron removal device 17 is for performing boron removal adsorption treatment on the concentrated water 300 discharged from the recovery nanofiltration unit 16. In particular, the concentrate 300 entering the second boron removal device 17 contains a significant amount of carbonate ions.
According to a preferred embodiment, the following table shows the elemental composition (in g/L) of the feed water to the first boron removal device 14 and the second boron removal device 17, in an alternative embodiment.
According to a preferred embodiment, the discharge requirements of the first boron removal device 14 are, for example: boron removal in produced water B - The content is less than 10ppm. The recovery rate of lithium is more than or equal to 98 percent. The water outlet pressure of the boron-removed produced water is not less than 0.4MPaG. The discharge requirements of the second boron removal device 17 are, for example: boron removal in produced water B - The content is less than 10ppm. The water outlet pressure of the boron-removing produced water is not less than0.4MpaG。
Further, after the produced water 200 discharged from each of the first and second boron removing apparatuses 14 and 17 enters the lithium precipitation plant 20, it is mixed in a predetermined ratio to form lithium carbonate precipitate by reaction. As shown in fig. 1, the supernatant 700 after lithium precipitation is filtered and then enters the lithium precipitation nanofiltration unit 19 for treatment. The produced water 200 discharged from the lithium precipitation nanofiltration unit 19 is returned to the lithium precipitation plant 20 to circulate the above-mentioned lithium carbonate precipitation reaction. The concentrated water 300 discharged from the lithium precipitation nanofiltration unit 19 enters the storage filtration unit 16 to circulate the above-mentioned carbonate concentration process.
According to a preferred embodiment, the following table shows the elemental composition (in g/L) of the feed water to the lithium precipitation nanofiltration unit 19 in an alternative embodiment.
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According to a preferred embodiment, the discharge requirements of the lithium precipitation nanofiltration unit 19 are, for example: lithium ions are remained on the water producing side as much as possible, and the lithium recovery rate is more than or equal to 90 percent. The carbonate content in the lithium precipitation nanofiltration produced water is less than 0.5g/L. The water yield of the lithium precipitation nanofiltration is not less than 0.4MPaG.
In particular, in the present invention, the multiple nanofiltration is to repeatedly separate monovalent anions, cations and divalent anions, cations, wherein the nanofiltration product water 200 generally contains relatively high contents of chloride, lithium, potassium and sodium ions, and relatively low contents of carbonate, bicarbonate and sulfate ions. The concentrated nanofiltration water 300 typically contains relatively high levels of carbonate, bicarbonate and sulfate ions, and relatively low levels of chloride, lithium, potassium and sodium ions. Particularly, in the invention, carbonate ions and lithium ions in the original brine 100 are separated for a plurality of times and are respectively combined, and finally the carbonate ions and the lithium ions which are respectively separated are mixed and reacted to form lithium carbonate, so that the extraction of the lithium ions is realized.
According to a preferred embodiment, as described above, the salt lake lithium extraction process of the present invention involves a plurality of circulating reflux treatment processes of concentrated water 300 and produced water 200, and specifically includes: the concentrated water 300 discharged from the first-stage nanofiltration device 6 is returned to the salt lake 21 to be mixed with the raw brine 100 and then recycled for the pretreatment, the pre-nanofiltration treatment, and the like. The produced water 200 discharged after the carbonate concentration treatment by the back receiving and filtering unit 16 flows back to the water inlet list of the multi-medium filter 2. The concentrated water 300 discharged after the carbonate concentration treatment by the back storage filter unit 16 enters the second boron removal device 17 and circulates the above-mentioned lithium precipitation treatment. Preferably, the recovery rate of the whole lithium ion purification process is improved by recirculating the brine after each stage of treatment.
According to a preferred embodiment, as shown in fig. 1, the present invention relates to a salt lake lithium extraction system, which may include:
the pretreatment unit is used for heating the raw brine 100, filtering out impurity particles therein and reducing the hardness of calcium and magnesium.
A pre-nanofiltration unit comprising at least two nanofiltration steps for separating chloride ions and carbonate ions from the raw brine 100 provided by the pretreatment unit, and providing produced water 200 to the first evaporative crystallisation apparatus 9 and a portion of the concentrate water 300 to the recovery nanofiltration unit 16.
A first evaporative crystallization device 9 for extracting sodium ions and potassium ions in the produced water 200 provided from the pre-nanofiltration unit to convert them into chloride 500 and providing a mother liquor 400 containing lithium ions to the multi-stage nanofiltration unit.
A multi-stage nanofiltration unit comprising at least three nanofiltration steps for separating chloride ions and carbonate ions from the produced water 200 provided by the first evaporative crystallisation apparatus 9 and providing the produced water 200 to the second evaporative crystallisation apparatus 13 and a portion of the concentrate 300 to the two-stage dialysis nanofiltration unit 15.
And a second evaporative crystallization device 13 for extracting sodium ions and potassium ions in the produced water 200 provided by the multi-stage nanofiltration unit to convert them into chloride 500, and providing a mother liquor 400 containing lithium ions to the first boron removal device 14.
A two-stage dialysis nanofiltration unit 15 for separating lithium ions and carbonate ions in a portion of the concentrate 300 provided by the multi-stage nanofiltration unit, and providing the produced water 200 to flow back to the multi-stage nanofiltration unit and the concentrate 300 to the recovery nanofiltration unit 16.
The first boron removing device 14 is used for performing boron removing resin adsorption on the mother liquor 400 provided by the second evaporation and crystallization device 13 and providing the produced water 200 to the lithium precipitation factory building 20.
The back receiving and filtering unit 16 is used for performing carbonate concentration treatment on the concentrated water 300 provided by the pre-nanofiltration unit and the two-stage dialysis nanofiltration unit 15, and providing the produced water 200 to flow back to the pre-treatment unit and providing the concentrated water 300 to the second boron removal device 17.
The second boron removing device 17 is used for performing boron removing resin adsorption on the concentrated water 300 provided by the recovery nanofiltration unit 16 and providing the produced water 200 to the lithium precipitation factory building 20.
A lithium precipitation plant 20 for mixing the produced water supplied from the first and second boron removal devices 14 and 17 in a predetermined ratio to form lithium carbonate precipitate, and supplying the supernatant 700 to the lithium precipitation nanofiltration unit 19.
The lithium precipitation nanofiltration unit 19 is used for separating lithium ions and carbonate ions in the supernatant 700 provided by the lithium precipitation plant 20, and providing the produced water 200 to flow back to the lithium precipitation plant 20 and the concentrated water 300 to flow back to the recovery nanofiltration unit 16.
According to a preferred embodiment, as shown in fig. 1, the pretreatment unit may comprise a heat exchanger 1, a multi-media filter 2, a self-cleaning filter 3, an ultrafiltration membrane apparatus 4, and a chelating resin column 5 connected in this order. Specifically, the raw brine 100 is first warmed up by the heat exchanger 1. Further, the raw brine 100 flows through the multi-medium filter 2, the self-cleaning filter 3 and the ultrafiltration membrane device 4 in sequence to filter out colloid and suspended particulate matters in the raw brine 100. The raw brine 100 is thereafter fed to a chelating resin column 5 for reducing the calcium magnesium hardness in the water.
According to a preferred embodiment, as shown in fig. 1, the pre-nanofiltration unit may comprise a primary nanofiltration device 6 and a secondary nanofiltration device 7. Specifically, the raw brine 100 flows through the primary nanofiltration device 6 and the secondary nanofiltration device 7 in sequence, so that monovalent chloride ions, secondary carbonate and sulfate radicals in the raw brine 100 are separated in the primary nanofiltration device 6 and the secondary nanofiltration device 7 respectively. Further, the concentrated water 300 produced by the first stage nanofiltration device 6 is returned to the salt lake 21. The concentrated water 300 produced by the secondary nanofiltration device 7 enters the storage and filtration unit 16.
According to a preferred embodiment, as shown in fig. 1, the multi-stage nanofiltration unit may comprise a three-stage nanofiltration device 10, a four-stage nanofiltration device 11 and a five-stage nanofiltration device 12. Specifically, the produced water discharged from the secondary nanofiltration device 7 in the pre-nanofiltration unit is first subjected to an evaporation crystallization treatment by the first crystallization evaporation device 9 to discharge the mother liquor 400 containing lithium ions. Further, the mother liquor 400 sequentially flows through the three-stage nanofiltration device 10, the four-stage nanofiltration device 11 and the five-stage nanofiltration device 12 to separate monovalent chloride ions and divalent carbonate and sulfate ions in the mother liquor 400 for multiple times by each stage nanofiltration.
In particular, the concentrated water 300 discharged from the three-stage nanofiltration device 10 and the four-stage nanofiltration device 11 is mixed into the two-stage dialysis nanofiltration unit 15 for recovering or separating monovalent lithium ions and divalent carbonate groups from the incoming water. Specifically, the two-stage dialysis nanofiltration unit 15 may include a first-stage dialysis nanofiltration device and a second-stage dialysis nanofiltration device connected in sequence, and the concentrate 300 enters the first-stage dialysis nanofiltration device and the second-stage dialysis nanofiltration device first and second and then to perform separation treatment of target ions. Further, the produced water 200 (containing more lithium ions) of the two-stage dialysis nanofiltration unit 15 flows back to the water inlet end of the four-stage nanofiltration device 11. The concentrated water 300 (containing more carbonate ions) discharged from the two-stage dialysis nanofiltration unit 15 enters the storage and filtration unit 16.
On the other hand, the concentrated water 300 discharged through the five-stage nanofiltration device 12 in the multi-stage nanofiltration unit is returned to the intermediate salt pan 8 downstream of the two-stage nanofiltration device 7.
According to a preferred embodiment, although a significant amount of calcium and magnesium has been removed by a pretreatment process prior to nanofiltration separation of the brine containing calcium and magnesium impurities, there is no guarantee that the raw brine 100 entering the nanofiltration stage does not contain any calcium and magnesium ions, even if its content is reduced to a negligible level. If the calcium and magnesium content in the final extracted lithium-containing product is high, the quality of the lithium carbonate product is affected, and especially for industrial grade lithium carbonate products, the requirements are more strict. These technical grade lithium carbonate products are often used as raw materials for battery grade lithium carbonate, which is used at high risk and significantly reduced in performance when the calcium and magnesium content is too high. Therefore, the content of calcium ions and magnesium ions is strictly controlled in the nanofiltration separation stage, so that the influence on the quality of lithium carbonate is reduced.
According to a preferred embodiment, the separation of anions and cations from the brine by nanofiltration is based on the selective permeability of nanofiltration membranes to ions of different valence states. In general, nanofiltration membranes are more prone to repel divalent ions. In most cases, nanofiltration membranes may be more selective rejection of divalent anions (including sulfate, carbonate) than divalent cations (including calcium, magnesium). Thus, when the raw brine 100 is passed through each nanofiltration device (6,7,10,11,12) for separation of anions and cations, more divalent anions (including sulfate, carbonate) may be more easily filtered out than divalent cations (including calcium, magnesium). In particular, after the concentration of divalent anions in the incoming water is continuously reduced, the separation repulsive effect on divalent cations may be inferior.
According to a preferred embodiment, the nanofiltration membrane will produce electrostatic adsorption against the separation rejection of divalent anions (e.g. sulfate, carbonate) in the incoming water when a certain concentration percentage is higher than the Total Dissolved Solids (TDS), e.g. calcium, magnesium ions. The electrostatic adsorption can improve separation and rejection of the nanofiltration membrane on divalent cations (comprising calcium ions and magnesium ions), especially in the state that the divalent cations in the residual produced water are low. In particular, the concentration percentage of divalent anions (e.g., sulfate, carbonate) compared to Total Dissolved Solids (TDS) can be determined by the designer through a limited number of experimental analyses.
According to a preferred embodiment, the concentration of divalent anions (e.g., sulfate, carbonate) in the raw brine 100 is generally higher than the concentration of dissolved total solids (TDS). When the raw brine 100 is subjected to nanofiltration separation by, for example, the primary nanofiltration device 6, the content of divalent anions in the produced water 200 of the primary nanofiltration device 6 is reduced, and the hardness is reduced. However, when the produced water 200 of the primary nanofiltration device 6 enters the secondary nanofiltration device 7, the hardness of the produced water 200 of the secondary nanofiltration device 7 may not be significantly reduced, and the desired softening degree may not be achieved. This is because the raw brine 100 has filtered out a large amount of divalent anions (including sulfate and carbonate) by the primary nanofiltration device 6, and the concentration difference between the divalent anions and the Total Dissolved Solids (TDS) in the incoming water of the secondary nanofiltration device 7 (the produced water 200 of the primary nanofiltration device 6) is smaller than that of the incoming water of the primary nanofiltration device 6, so that no obvious electrostatic adsorption effect is generated, and the separation rejection of the nanofiltration membrane on calcium ions and magnesium ions is remarkably reduced.
According to a preferred embodiment, in order to increase the filtering effect of the downstream nanofiltration device on calcium ions and magnesium ions in the incoming water, an aqueous solution containing divalent anions (including sulfate and carbonate) with a preset concentration may be mixed into the produced water of the upper nanofiltration device before the produced water of the upper nanofiltration device enters the lower nanofiltration device. Specifically, depending on the concentration value of the Total Dissolved Solids (TDS) in the produced water of the upper stage nanofiltration device, the produced water of the upper stage nanofiltration device is mixed in such a manner that the concentration value of the aqueous solution containing divalent anions (including sulfate, carbonate) and the concentration value of the Total Dissolved Solids (TDS) at present are maintained in a predetermined concentration ratio interval. For example, the concentration of the aqueous solution containing divalent anions (including sulfate, carbonate) mixed into the water produced by the upper nanofiltration device may be 0.7 to 0.9 times the concentration of the Total Dissolved Solids (TDS) therein or more. Preferably, when the concentration of divalent anions (including sulfate, carbonate) and the concentration of dissolved total solids (TDS) in water are maintained in a predetermined concentration ratio interval, there is no large concentration difference between divalent anions (including sulfate, carbonate) and dissolved total solids (TDS). Further, when filtration against divalent anions (including sulfate, carbonate) is provided by the nanofiltration membrane, the nanofiltration membrane produces electrostatic adsorption against divalent anions (including sulfate, carbonate) separation rejection, which promotes separation rejection of the nanofiltration membrane against dissolved total solids (including calcium ions, magnesium ions), thereby significantly improving the water quality hardness of the upstream produced water or the downstream water.
According to a preferred embodiment, in particular, the aqueous solution containing divalent anions (including sulfate, carbonate) may come partly from the nanofiltration concentrate of each stage. Preferably, the aqueous solution containing divalent anions (including sulfate, carbonate) may be derived from the primary nanofiltration concentrate, since the primary nanofiltration concentrate has a relatively high sulfate, carbonate content. Preferably, the molar concentration of divalent anions (including sulfate, carbonate) in the primary nanofiltration concentrate can be adjusted by solution configuration. The partial aqueous solution containing divalent anions (including sulfate radicals and carbonate radicals) in the original brine 100 is mixed into the incoming water of the lower nanofiltration device, so that the hardness of the produced water of the lower nanofiltration device can be obviously reduced, the recycling of substances can be realized, and the input consumption of resources outside a system can be reduced.
Preferably, the present invention comprises a multi-stage nanofiltration process. Before the water produced by any stage of nanofiltration enters a lower stage nanofiltration device, the hardness of the water produced by multistage nanofiltration is obviously reduced by mixing an aqueous solution containing divalent anions (including sulfate radicals and carbonate radicals) and keeping the concentration value of the aqueous solution and the concentration value of Total Dissolved Solids (TDS) in the aqueous solution within a preset concentration ratio range.
According to a preferred embodiment, the salt lake lithium extraction system of the present invention may further include a pure water reverse osmosis unit (not shown). The pure water reverse osmosis unit is used for preparing pure water solvent for preparing alkali liquor (sodium hydroxide solution) and salt solution (sodium chloride solution).
It should be noted that the above-described embodiments are exemplary, and that a person skilled in the art, in light of the present disclosure, may devise various solutions that fall within the scope of the present disclosure and fall within the scope of the present disclosure. It should be understood by those skilled in the art that the present description and drawings are illustrative and not limiting to the claims. The scope of the invention is defined by the claims and their equivalents. The description of the invention encompasses multiple inventive concepts, such as "preferably," "according to a preferred embodiment," or "optionally," all means that the corresponding paragraph discloses a separate concept, and that the applicant reserves the right to filed a divisional application according to each inventive concept.
Claims (10)
1. A method for extracting lithium from a salt lake, comprising the steps of:
pre-nanofiltration of raw brine (100) extracted from a salt lake (21) comprising at least two nanofiltration processes;
Performing primary evaporative crystallization on the pre-nanofiltration produced water (200) to obtain a mother solution (400) containing lithium ions;
subjecting the mother liquor (400) to a multistage nanofiltration comprising at least three nanofiltration processes;
performing secondary evaporation crystallization on the product water (200) after the multistage nanofiltration;
performing secondary dialysis nanofiltration on part of concentrated water (300) after the multistage nanofiltration, and refluxing produced water (200) after the secondary dialysis nanofiltration to the multistage nanofiltration;
performing a first boron removal adsorption on the mother liquor (400) after the secondary evaporation crystallization to obtain produced water (200) for forming lithium carbonate precipitate;
mixing the part of concentrated water (300) after the pre-nanofiltration and the concentrated water (300) after the secondary dialysis nanofiltration to carry out carbonate storage and filtration, and enabling the product water (200) after the carbonate storage and filtration to flow back to pretreatment, and carrying out second boron removal adsorption on the concentrated water (300) after the carbonate storage and filtration, so that the product water (200) after the second boron removal adsorption and the product water (200) after the first boron removal adsorption are mixed to form lithium carbonate precipitation.
2. The method according to claim 1, characterized in that before the pre-nanofiltration of the raw brine (100) extracted from the salt lake (21) comprising at least two nanofiltration processes, it further comprises:
Pretreatment of raw brine (100) extracted from a salt lake (21), and the pretreatment comprises:
carrying out heat exchange treatment on the raw brine (100) to heat the raw brine to a preset temperature;
performing multistage filtration on the raw brine (100) after temperature rise to remove colloid and suspended matters in the raw brine;
and (3) carrying out resin adsorption on the raw brine (100) subjected to the multistage filtration to reduce the hardness of calcium and magnesium in water.
3. The method according to claim 1, wherein said pre-nanofiltration of the pre-treated raw brine (100) comprising at least two nanofiltration processes comprises:
carrying out first-stage nanofiltration on the pretreated raw brine (100) to carry out first-stage separation on chloride ions, carbonate and sulfate radicals in the raw brine (100), wherein concentrated water (300) subjected to the first-stage nanofiltration flows back to a salt lake (21);
and carrying out second-stage nanofiltration on the first-stage nanofiltration produced water (200) so as to carry out second separation on the chloride ions, carbonate and sulfate radicals, wherein the second-stage nanofiltration produced water (200) flows to the primary evaporation crystallization, and the second-stage nanofiltration concentrated water (300) flows to the carbonate back storage filtration.
4. The method according to claim 1, wherein said subjecting the mother liquor (400) to a multi-stage nanofiltration comprising at least three nanofiltration processes comprises:
Performing third-stage nanofiltration on the mother liquor (400) after primary evaporation crystallization to perform third separation on chloride ions, carbonate and sulfate, wherein concentrated water (300) of the third-stage nanofiltration flows to the second-stage dialysis nanofiltration;
performing a fourth stage nanofiltration of the third stage nanofiltration product water (200) to fourth separate the chloride ions and carbonate and sulfate, wherein the fourth stage nanofiltration concentrate water (300) flows to the second stage dialysis nanofiltration;
and carrying out fifth-stage nanofiltration on the fourth-stage nanofiltration produced water (200) so as to carry out fifth separation on the chloride ions, carbonate and sulfate radicals, wherein concentrated water (300) of the fifth-stage nanofiltration flows to an intermediate salt pan (8), and the fifth-stage nanofiltration produced water (200) flows to the secondary evaporation crystallization.
5. The method of claim 4, wherein said performing a second-stage dialysis nanofiltration of said multi-stage nanofiltration of said partially concentrated water (300) comprises:
mixing the third-stage nanofiltration concentrated water (300) and the fourth-stage nanofiltration concentrated water (300), sequentially performing first-stage dialysis nanofiltration and second-stage dialysis nanofiltration on the mixed concentrated water flow to separate and recycle lithium ions and carbonate radicals,
Wherein the product water (200) after the second-stage dialysis nanofiltration is provided to the water inlet end of the fourth-stage nanofiltration.
6. A method according to claim 3, characterized in that before the second stage nanofiltration of the first stage nanofiltration produced water (200) further comprises:
and adjusting the pH of the first-stage nanofiltration produced water (200) by alkali liquor so as to convert bicarbonate in the first-stage nanofiltration produced water (200) into carbonate.
7. The method of claim 4, further comprising, prior to fourth stage nanofiltration of the third stage nanofiltration produced water (200):
and adjusting the pH of the third-stage nanofiltration produced water (200) by alkali liquor so as to convert bicarbonate in the third-stage nanofiltration produced water (200) into carbonate.
8. The method of claim 1, wherein the mixing the second boron-depleted water (200) with the first boron-depleted water (200) to form a lithium carbonate precipitate further comprises:
filtering the supernatant (700) after the lithium carbonate precipitation to form a lithium precipitation mother solution (800);
carrying out lithium precipitation nanofiltration on the lithium precipitation mother solution (800) so as to separate and recycle lithium ions and carbonate radicals in the lithium precipitation mother solution;
a step of refluxing the lithium precipitation nanofiltration product water (200) to form the lithium carbonate precipitate; and
And enabling the concentrated water (300) after the lithium precipitation nanofiltration to flow to the carbonate storage filter.
9. The method according to claim 1, characterized in that an aqueous solution containing divalent anions is mixed into the produced water (200) of the upper nanofiltration device in such a way that its concentration value is kept in a predetermined concentration ratio interval with the concentration value of dissolved total solids in the produced water (200) of the upper nanofiltration device before the produced water (200) of the upper nanofiltration device enters the lower nanofiltration device, wherein the aqueous solution containing divalent anions is at least partly derived from the concentrate (300) of the upper nanofiltration device.
10. A salt lake lithium extraction system, comprising:
a pretreatment unit for pretreating raw brine (100) extracted from a salt lake (21);
a pre-nanofiltration unit for pre-nanofiltration of the pretreated raw brine (100) comprising at least two nanofiltration processes;
a first evaporative crystallization device (9) for performing primary evaporative crystallization on the pre-nanofiltration produced water (200) to obtain a mother liquor (400) containing lithium ions;
a multi-stage nanofiltration unit for performing multi-stage nanofiltration of the mother liquor (400) comprising at least three nanofiltration processes;
The second evaporation crystallization device (13) is used for performing secondary evaporation crystallization on the product water (200) after the multistage nanofiltration;
a two-stage dialysis nanofiltration unit (15) for performing a two-stage dialysis nanofiltration on a part of the concentrated water (300) after the multi-stage nanofiltration and providing produced water (200) to the multi-stage nanofiltration unit;
a first boron removal device (14) for performing a first boron removal adsorption on the mother liquor (400) after the secondary evaporation crystallization to obtain a produced water (200) for forming lithium carbonate precipitate;
a back storage filter unit (16) for carrying out carbonate concentration treatment on part of the concentrated water (300) provided by the pre-nanofiltration unit and the concentrated water (300) provided by the two-stage dialysis nanofiltration unit (15), and providing produced water (200) to flow back to the pretreatment unit;
a second boron removal device (17) for performing a second boron removal adsorption on the concentrated water (300) discharged from the recovery nanofiltration unit (16) to provide a produced water (200) for mixing with the first boron removed adsorbed produced water (200) to form a lithium carbonate precipitate;
a lithium precipitation nanofiltration unit (19) for separating lithium ions and carbonate ions in the supernatant (700) provided by the step of lithium carbonate precipitation, and providing a reflux of produced water (200) to the step of forming the lithium carbonate precipitation.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106082284A (en) * | 2016-06-08 | 2016-11-09 | 北京清源创智科技有限公司 | The production method of LITHIUM BATTERY pure Lithium Carbonate |
| CN108275703A (en) * | 2018-04-10 | 2018-07-13 | 中蓝长化工程科技有限公司 | A kind of technique for producing lithium carbonate and salt potassium coproduction with the nanofiltration production water containing lithium |
| CN108314065A (en) * | 2018-02-09 | 2018-07-24 | 陕西省膜分离技术研究院有限公司 | Divide the full membrane separating method that salt produces lithium liquor by salt lake bittern multistage nanofiltration |
| CN111252788A (en) * | 2020-04-03 | 2020-06-09 | 启迪清源（北京）科技有限公司 | Method for preparing high-purity lithium carbonate by using fractional crystallization technology |
| CN111606334A (en) * | 2020-07-01 | 2020-09-01 | 启迪清源（北京）科技有限公司 | Method for converting carbonate type salt lake brine into chloride type brine |
| CN218434927U (en) * | 2022-11-02 | 2023-02-03 | 倍杰特集团股份有限公司 | Salt lake lithium extraction process system |
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| US10669168B2 (en) * | 2016-11-29 | 2020-06-02 | China Petroleum & Chemical Corporation | Method and system for treating brine waste water |
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Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106082284A (en) * | 2016-06-08 | 2016-11-09 | 北京清源创智科技有限公司 | The production method of LITHIUM BATTERY pure Lithium Carbonate |
| CN108314065A (en) * | 2018-02-09 | 2018-07-24 | 陕西省膜分离技术研究院有限公司 | Divide the full membrane separating method that salt produces lithium liquor by salt lake bittern multistage nanofiltration |
| CN108275703A (en) * | 2018-04-10 | 2018-07-13 | 中蓝长化工程科技有限公司 | A kind of technique for producing lithium carbonate and salt potassium coproduction with the nanofiltration production water containing lithium |
| CN111252788A (en) * | 2020-04-03 | 2020-06-09 | 启迪清源（北京）科技有限公司 | Method for preparing high-purity lithium carbonate by using fractional crystallization technology |
| CN111606334A (en) * | 2020-07-01 | 2020-09-01 | 启迪清源（北京）科技有限公司 | Method for converting carbonate type salt lake brine into chloride type brine |
| CN218434927U (en) * | 2022-11-02 | 2023-02-03 | 倍杰特集团股份有限公司 | Salt lake lithium extraction process system |
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