CN110713197A - Method for recovering lithium salt from mother liquor generated in preparation of lithium iron phosphate by hydrothermal method - Google Patents
Method for recovering lithium salt from mother liquor generated in preparation of lithium iron phosphate by hydrothermal method Download PDFInfo
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- CN110713197A CN110713197A CN201810757777.0A CN201810757777A CN110713197A CN 110713197 A CN110713197 A CN 110713197A CN 201810757777 A CN201810757777 A CN 201810757777A CN 110713197 A CN110713197 A CN 110713197A
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- Prior art keywords
- lithium
- suspension
- iron phosphate
- mother liquor
- drying
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- 238000000034 method Methods 0.000 title claims abstract description 70
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 title claims abstract description 67
- 239000012452 mother liquor Substances 0.000 title claims abstract description 59
- 238000001027 hydrothermal synthesis Methods 0.000 title claims abstract description 53
- 159000000002 lithium salts Chemical class 0.000 title claims abstract description 39
- 229910003002 lithium salt Inorganic materials 0.000 title claims abstract description 38
- 238000002360 preparation method Methods 0.000 title claims abstract description 13
- 239000000725 suspension Substances 0.000 claims abstract description 70
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 claims abstract description 46
- 229910001416 lithium ion Inorganic materials 0.000 claims abstract description 39
- 238000010008 shearing Methods 0.000 claims abstract description 29
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 claims abstract description 25
- 238000006243 chemical reaction Methods 0.000 claims abstract description 24
- 238000010333 wet classification Methods 0.000 claims abstract description 23
- 230000001804 emulsifying effect Effects 0.000 claims abstract description 21
- 238000004108 freeze drying Methods 0.000 claims abstract description 21
- 239000000843 powder Substances 0.000 claims abstract description 21
- 238000000227 grinding Methods 0.000 claims abstract description 19
- 239000000463 material Substances 0.000 claims abstract description 19
- 229910017053 inorganic salt Inorganic materials 0.000 claims abstract description 18
- 238000001035 drying Methods 0.000 claims abstract description 17
- 238000000352 supercritical drying Methods 0.000 claims abstract description 16
- 239000010413 mother solution Substances 0.000 claims abstract description 12
- 239000010405 anode material Substances 0.000 claims abstract description 9
- 238000010532 solid phase synthesis reaction Methods 0.000 claims abstract description 7
- 230000001376 precipitating effect Effects 0.000 claims abstract description 6
- 239000007784 solid electrolyte Substances 0.000 claims abstract description 4
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 42
- 238000001914 filtration Methods 0.000 claims description 37
- 239000012535 impurity Substances 0.000 claims description 34
- 229910052808 lithium carbonate Inorganic materials 0.000 claims description 33
- 239000000243 solution Substances 0.000 claims description 33
- 238000001556 precipitation Methods 0.000 claims description 28
- 229910001386 lithium phosphate Inorganic materials 0.000 claims description 24
- TWQULNDIKKJZPH-UHFFFAOYSA-K trilithium;phosphate Chemical compound [Li+].[Li+].[Li+].[O-]P([O-])([O-])=O TWQULNDIKKJZPH-UHFFFAOYSA-K 0.000 claims description 24
- 239000002244 precipitate Substances 0.000 claims description 21
- 230000008569 process Effects 0.000 claims description 21
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims description 19
- 229910052744 lithium Inorganic materials 0.000 claims description 19
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 claims description 17
- 238000010438 heat treatment Methods 0.000 claims description 17
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 claims description 16
- 239000000706 filtrate Substances 0.000 claims description 16
- 239000000203 mixture Substances 0.000 claims description 15
- 239000002002 slurry Substances 0.000 claims description 15
- GCLGEJMYGQKIIW-UHFFFAOYSA-H sodium hexametaphosphate Chemical compound [Na]OP1(=O)OP(=O)(O[Na])OP(=O)(O[Na])OP(=O)(O[Na])OP(=O)(O[Na])OP(=O)(O[Na])O1 GCLGEJMYGQKIIW-UHFFFAOYSA-H 0.000 claims description 14
- 235000019982 sodium hexametaphosphate Nutrition 0.000 claims description 14
- 239000001577 tetrasodium phosphonato phosphate Substances 0.000 claims description 14
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims description 13
- VMHLLURERBWHNL-UHFFFAOYSA-M Sodium acetate Chemical compound [Na+].CC([O-])=O VMHLLURERBWHNL-UHFFFAOYSA-M 0.000 claims description 13
- 150000001768 cations Chemical class 0.000 claims description 13
- 239000001632 sodium acetate Substances 0.000 claims description 13
- 235000017281 sodium acetate Nutrition 0.000 claims description 13
- 238000011084 recovery Methods 0.000 claims description 12
- AKHNMLFCWUSKQB-UHFFFAOYSA-L sodium thiosulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=S AKHNMLFCWUSKQB-UHFFFAOYSA-L 0.000 claims description 12
- 235000019345 sodium thiosulphate Nutrition 0.000 claims description 12
- USFZMSVCRYTOJT-UHFFFAOYSA-N Ammonium acetate Chemical compound N.CC(O)=O USFZMSVCRYTOJT-UHFFFAOYSA-N 0.000 claims description 11
- 239000005695 Ammonium acetate Substances 0.000 claims description 11
- 229940043376 ammonium acetate Drugs 0.000 claims description 11
- 235000019257 ammonium acetate Nutrition 0.000 claims description 11
- 229920002545 silicone oil Polymers 0.000 claims description 10
- 238000005406 washing Methods 0.000 claims description 10
- 238000004064 recycling Methods 0.000 claims description 9
- 229910000147 aluminium phosphate Inorganic materials 0.000 claims description 8
- 239000010406 cathode material Substances 0.000 claims description 8
- 239000007788 liquid Substances 0.000 claims description 8
- 229910000029 sodium carbonate Inorganic materials 0.000 claims description 8
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims description 7
- 229910002092 carbon dioxide Inorganic materials 0.000 claims description 7
- 239000006185 dispersion Substances 0.000 claims description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 7
- 235000011114 ammonium hydroxide Nutrition 0.000 claims description 6
- 239000001569 carbon dioxide Substances 0.000 claims description 6
- 238000004945 emulsification Methods 0.000 claims description 6
- 238000000926 separation method Methods 0.000 claims description 6
- 239000007787 solid Substances 0.000 claims description 6
- 238000003756 stirring Methods 0.000 claims description 6
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims description 5
- 239000003513 alkali Substances 0.000 claims description 5
- 238000001704 evaporation Methods 0.000 claims description 5
- 229910052698 phosphorus Inorganic materials 0.000 claims description 5
- 239000011574 phosphorus Substances 0.000 claims description 5
- 239000007774 positive electrode material Substances 0.000 claims description 5
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 claims description 4
- 229910019142 PO4 Inorganic materials 0.000 claims description 4
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 claims description 4
- 150000001450 anions Chemical class 0.000 claims description 4
- 239000002518 antifoaming agent Substances 0.000 claims description 4
- 239000000919 ceramic Substances 0.000 claims description 4
- 238000002425 crystallisation Methods 0.000 claims description 4
- 230000008025 crystallization Effects 0.000 claims description 4
- 239000012065 filter cake Substances 0.000 claims description 4
- HQRPHMAXFVUBJX-UHFFFAOYSA-M lithium;hydrogen carbonate Chemical compound [Li+].OC([O-])=O HQRPHMAXFVUBJX-UHFFFAOYSA-M 0.000 claims description 4
- 238000004519 manufacturing process Methods 0.000 claims description 4
- 238000005374 membrane filtration Methods 0.000 claims description 4
- 238000003825 pressing Methods 0.000 claims description 4
- 229910052938 sodium sulfate Inorganic materials 0.000 claims description 4
- 235000011152 sodium sulphate Nutrition 0.000 claims description 4
- 230000008020 evaporation Effects 0.000 claims description 3
- 239000003792 electrolyte Substances 0.000 claims description 2
- 238000005194 fractionation Methods 0.000 claims description 2
- 239000010842 industrial wastewater Substances 0.000 claims description 2
- 150000002500 ions Chemical class 0.000 claims description 2
- 239000007773 negative electrode material Substances 0.000 claims description 2
- 238000001694 spray drying Methods 0.000 claims description 2
- 239000002270 dispersing agent Substances 0.000 claims 1
- 239000003995 emulsifying agent Substances 0.000 claims 1
- 239000007790 solid phase Substances 0.000 claims 1
- 239000002245 particle Substances 0.000 abstract description 26
- 238000005054 agglomeration Methods 0.000 abstract description 9
- 230000002194 synthesizing effect Effects 0.000 abstract description 8
- 230000002776 aggregation Effects 0.000 abstract description 5
- 239000005955 Ferric phosphate Substances 0.000 abstract description 2
- 229940032958 ferric phosphate Drugs 0.000 abstract description 2
- WBJZTOZJJYAKHQ-UHFFFAOYSA-K iron(3+) phosphate Chemical compound [Fe+3].[O-]P([O-])([O-])=O WBJZTOZJJYAKHQ-UHFFFAOYSA-K 0.000 abstract description 2
- 229910000399 iron(III) phosphate Inorganic materials 0.000 abstract description 2
- KWGKDLIKAYFUFQ-UHFFFAOYSA-M lithium chloride Chemical compound [Li+].[Cl-] KWGKDLIKAYFUFQ-UHFFFAOYSA-M 0.000 description 10
- 230000000052 comparative effect Effects 0.000 description 9
- 238000002156 mixing Methods 0.000 description 5
- 239000007789 gas Substances 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- 238000005086 pumping Methods 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 239000012295 chemical reaction liquid Substances 0.000 description 3
- 238000009616 inductively coupled plasma Methods 0.000 description 3
- 239000011159 matrix material Substances 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 239000002994 raw material Substances 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- JJLJMEJHUUYSSY-UHFFFAOYSA-L copper(II) hydroxide Inorganic materials [OH-].[OH-].[Cu+2] JJLJMEJHUUYSSY-UHFFFAOYSA-L 0.000 description 2
- AEJIMXVJZFYIHN-UHFFFAOYSA-N copper;dihydrate Chemical compound O.O.[Cu] AEJIMXVJZFYIHN-UHFFFAOYSA-N 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000011790 ferrous sulphate Substances 0.000 description 2
- 235000003891 ferrous sulphate Nutrition 0.000 description 2
- 239000011888 foil Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 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
- FLTRNWIFKITPIO-UHFFFAOYSA-N iron;trihydrate Chemical compound O.O.O.[Fe] FLTRNWIFKITPIO-UHFFFAOYSA-N 0.000 description 2
- 229910000032 lithium hydrogen carbonate Inorganic materials 0.000 description 2
- IPJKJLXEVHOKSE-UHFFFAOYSA-L manganese dihydroxide Chemical compound [OH-].[OH-].[Mn+2] IPJKJLXEVHOKSE-UHFFFAOYSA-L 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 238000007670 refining Methods 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- 239000002351 wastewater Substances 0.000 description 2
- 238000005303 weighing Methods 0.000 description 2
- WQZGKKKJIJFFOK-GASJEMHNSA-N Glucose Natural products OC[C@H]1OC(O)[C@H](O)[C@@H](O)[C@@H]1O WQZGKKKJIJFFOK-GASJEMHNSA-N 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- 239000003125 aqueous solvent Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000006258 conductive agent Substances 0.000 description 1
- 238000009831 deintercalation Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 239000002612 dispersion medium Substances 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000007580 dry-mixing Methods 0.000 description 1
- 239000000839 emulsion Substances 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 239000008103 glucose Substances 0.000 description 1
- 238000009775 high-speed stirring Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000009830 intercalation Methods 0.000 description 1
- 230000002687 intercalation Effects 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- INHCSSUBVCNVSK-UHFFFAOYSA-L lithium sulfate Inorganic materials [Li+].[Li+].[O-]S([O-])(=O)=O INHCSSUBVCNVSK-UHFFFAOYSA-L 0.000 description 1
- 239000002609 medium Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000010450 olivine Substances 0.000 description 1
- 229910052609 olivine Inorganic materials 0.000 description 1
- 238000000643 oven drying Methods 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 239000002243 precursor Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000012047 saturated solution Substances 0.000 description 1
- 229910001251 solid state electrolyte alloy Inorganic materials 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
- C01D15/00—Lithium compounds
- C01D15/08—Carbonates; Bicarbonates
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B25/00—Phosphorus; Compounds thereof
- C01B25/16—Oxyacids of phosphorus; Salts thereof
- C01B25/26—Phosphates
- C01B25/30—Alkali metal phosphates
- C01B25/301—Preparation from liquid orthophosphoric acid or from an acid solution or suspension of orthophosphates
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/54—Reclaiming serviceable parts of waste accumulators
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/51—Particles with a specific particle size distribution
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/60—Particles characterised by their size
- C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer
-
- 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
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/84—Recycling of batteries or fuel cells
Abstract
The invention discloses a method for recovering lithium salt from mother liquor generated in preparation of lithium iron phosphate by a hydrothermal method, which comprises the following steps: 1) li is carried out on mother solution generated by preparing lithium iron phosphate by hydrothermal method+Precipitating; 2) then adding inorganic salt grinding aid into the obtained lithium salt-containing suspension for shearing, emulsifying and dispersing under the condition of the rotating speed of more than or equal to 2000 r/min; 3) wet classification; 4) and (3) drying by adopting a freeze drying and/or supercritical drying mode, and recovering to obtain the lithium salt. The method of the invention can not only prevent the agglomeration of particles during the reaction generation, but also prevent the re-agglomeration during the subsequent wet classification and drying, obtain the superfine lithium carbonate powder or the lithium iron phosphate powder with good uniformity and good dispersibility, and the obtained superfine lithium carbonate powder can be directly used for preparing lithium ion battery materials by a solid phase method or preparing full-scale lithium ion battery materialsA solid electrolyte; the obtained superfine ferric phosphate powder can be directly used for synthesizing the lithium iron phosphate anode material by a hydrothermal method.
Description
Technical Field
The invention relates to the field of lithium ion battery anode materials, relates to a method for recovering lithium salt from a mother liquor generated by preparing lithium iron phosphate by a hydrothermal method, and particularly relates to a method for recovering superfine lithium carbonate or superfine lithium phosphate from the mother liquor generated by preparing lithium iron phosphate by the hydrothermal method.
Background
In 1997, Goodenough and the like report for the first time that lithium iron phosphate with an olivine structure can be used as a lithium battery, and have attracted extensive attention and a great deal of research, the lithium iron phosphate has a theoretical specific capacity of 170mAh/g and a 3.5V lithium charging platform, and compared with the traditional lithium battery material, the lithium iron phosphate has the advantages of wide raw material source, low cost, no environmental pollution, good cycle performance, good thermal stability, outstanding safety performance and the like, and is an ideal anode material of a power type lithium ion battery.
Domestic lithium iron phosphate anode material production and manufacturing enterprises are limited by technical reserve and early investment, and adopt solid-phase synthesis processes. In recent years, with the continuous temperature rise of lithium ion battery applications, especially in new energy vehicles and energy storage applications, the industry still shows a high-speed growth situation. The "industry structure adjustment guide catalogue" issued by the national improvement commission places the manufacture of high-tech green batteries such as lithium ion batteries and the like as a high-tech industry in a position with priority for development. Along with the increase of national policy and the continuous widening of the application field of the lithium iron phosphate battery, the demand and the performance requirement on the lithium iron phosphate cathode material are also continuously improved, the product consistency of the hydrothermal synthesis process is high, and the multiplying power and the low-temperature performance are excellent, so that the hydrothermal synthesis process is undoubtedly the optimal choice for meeting the current application demand. However, the hydrothermal process has a certain defect that the utilization rate of lithium in the raw material is low, and a large amount of lithium exists in the form of ions in the mother liquor after the reaction due to the limitation of the reaction conditions.
For example, CN 101327920a discloses a flaky lithium iron phosphate nanocrystalline powder and a preparation method thereof, wherein a flaky nanocrystalline lithium iron phosphate anode material with an obvious (020) orientation is obtained by mixing a lithium source, an iron source and a phosphorus source and transferring the mixture to a hydrothermal reaction kettle for reaction for a period of time, and the material has a developed lithium ion intercalation/deintercalation channel. CN 102897803B discloses a method for recycling mother liquor generated in a method for preparing lithium iron phosphate by a hydrothermal method, which comprises the steps of preparing a blending solution, LiCl slurry, a lithium chloride solution, a LiCl refining solution 1, a LiCl refining solution 2, and the like, thereby realizing the recycling of lithium in the mother liquor for synthesizing lithium iron phosphate by the hydrothermal method, but the lithium salt obtained by recycling in the method is lithium chloride, while the lithium salt for synthesizing a lithium battery material at present is lithium carbonate, so the method cannot directly utilize the recycled lithium salt in the synthesis of the material.
Therefore, the comprehensive utilization rate of the lithium source in the process of preparing the lithium iron phosphate by the hydrothermal method is improved, so that the popularization of the hydrothermal method preparation process is facilitated, and the preparation of the high-quality lithium salt which can be directly used for preparing the lithium ion battery has important practical significance.
Disclosure of Invention
Aiming at the defects of the prior art, the invention aims to provide a method for recovering lithium salt from a mother liquor generated by preparing lithium iron phosphate by a hydrothermal method.
The "superfine" in the "superfine lithium carbonate powder" and the "superfine lithium phosphate powder" of the present invention means: the particle size distribution has a D90<10 μm.
In order to achieve the purpose, the invention adopts the following technical scheme:
the invention provides a method for recovering lithium salt from a mother solution generated by preparing lithium iron phosphate by a hydrothermal method, which comprises the following steps:
(1) li is carried out on mother solution generated by preparing lithium iron phosphate by hydrothermal method+Precipitating;
(2) then adding inorganic salt grinding aid into the obtained lithium salt suspension, and carrying out shearing, emulsifying and dispersing under the condition of the rotating speed of more than or equal to 2000 r/min;
(3) wet classification;
(4) and (3) drying by adopting a freeze drying and/or supercritical drying mode, and recovering to obtain the lithium salt.
The rotating speed of the shearing, emulsifying and dispersing in the step (2) of the invention is more than or equal to 2000r/min, such as 2000r/min, 3000r/min, 4500r/min, 6000r/min, 6500r/min, 7000r/min, 8000r/min, 9000r/min, 10000r/min, 12000r/min, 13500r/min, 15000r/min, 17000r/min, 18000r/min, 19000r/min or 20000r/min, and the like, and is preferably 6000r/min-20000 r/min.
The "freeze drying and/or supercritical drying method" in step (4) of the present invention means: the drying may be freeze-drying, supercritical drying, or a combination of freeze-drying and supercritical drying.
According to the invention, the inorganic salt grinding aid is used for shearing, emulsifying and dispersing at a rotating speed of more than or equal to 2000r/min, and then the wet classification is carried out to remove large particles, so that not only can agglomeration of particles generated by reaction be avoided, but also the particle size uniformity of the particles can be improved, and finally, the freeze drying and/or supercritical drying manner adopted by drying can avoid the problem of re-agglomeration of solid particles caused by volatilization of a conventional drying and dispersing medium, so that ultrafine powder with uniform particle size can be obtained.
The method is only suitable for recovering the lithium salt from the mother liquor generated by preparing the lithium iron phosphate by the hydrothermal method, but not suitable for recovering the lithium salt from the mother liquor generated by preparing the lithium iron phosphate by other non-aqueous solvent thermal methods.
In the invention, in the mother liquor generated by preparing lithium iron phosphate by the hydrothermal method, the main cation is Li+The main anion being SO4 2-。
Preferably, in the mother liquor generated by preparing lithium iron phosphate by the hydrothermal method, Li+At a concentration of 0-1.2g/100g, e.g., 0, 0.1g/100g, 0.5g/100g, 0.6g/100g, 0.7g/100g, 0.8g/100g, 0.9g/100g, 1.0g/100g, 1.1g/100g, or 1.2g/100g, etc., of the Li+The concentration of 0 means that Li is not contained in the mother solution generated by preparing lithium iron phosphate by a hydrothermal method+。
Preferably, in the mother liquor generated in the hydrothermal method for preparing lithium iron phosphate, the cations further include Fe2+And/or Fe3+(ii) a The anion also comprising PO4 3-、HPO4 2-Or H2PO4 -Any one or a combination of at least two of them.
Preferably, in the mother liquor generated by preparing lithium iron phosphate by the hydrothermal method, the cations may also include doped cations, and the doped cations include Cu2+、Co3+、Ni2+Or Mn2+Any one or a combination of at least two of them.
As a preferable embodiment of the recovery method of the present invention, the recovery method further comprises: in Li+Step (1)' is performed before precipitation: the mother liquor is subjected to impurity removal so as to remove Li+And removing other cations from the mother liquor, and taking the filtrate to obtain the mother liquor after impurity removal.
Preferably, the step (1)' the specific step of removing impurities comprises: heating mother liquor generated by preparing lithium iron phosphate by a hydrothermal method, adding alkali to adjust the pH value, filtering after the reaction is finished, and taking filtrate to obtain the mother liquor after impurity removal.
Preferably, in the step (1)' impurity removal process, the heating is carried out at a temperature of 70 ℃ to 95 ℃, for example, 70 ℃, 72 ℃, 75 ℃, 80 ℃, 84 ℃, 86 ℃, 90 ℃ or 95 ℃.
Preferably, in the process of removing impurities in step (1)', the heating rate is 0.1 ℃/min-5 ℃/min, such as 0.1 ℃/min, 0.5 ℃/min, 1 ℃/min, 1.5 ℃/min, 2 ℃/min, 3 ℃/min, 3.5 ℃/min, 4 ℃/min or 5 ℃/min, etc.
Preferably, in the process of removing impurities in the step (1)', the alkali is sodium hydroxide powder or sodium hydroxide solution.
Preferably, during the removal of impurities in step (1)', the pH is adjusted to a value of 8-12, such as 8, 9, 10, 11 or 12, etc.
Preferably, in the process of removing impurities in the step (1)', the filtration method includes, but is not limited to, any one of centrifugal filtration, ceramic membrane filtration or plate-and-frame filter pressing.
As a preferable embodiment of the recovery method of the present invention, the recovery method further comprises: after wet fractionation, before freeze-drying and/or supercritical drying, step (4)': filtering and washing the solid obtained by filtering, or concentrating, filtering and washing the solid obtained by filtering.
Preferably, the inorganic salt grinding aid in the step (2) is any one or a mixture of at least two of sodium acetate, ammonium acetate, sodium thiosulfate or sodium hexametaphosphate, and the mixture is typically but not limited to: mixtures of sodium acetate and ammonium acetate, mixtures of sodium acetate and sodium thiosulfate, mixtures of sodium acetate and sodium hexametaphosphate, mixtures of ammonium acetate and sodium thiosulfate, mixtures of sodium acetate, ammonium acetate, sodium thiosulfate, and sodium hexametaphosphate, and the like.
Preferably, the shearing emulsifying and dispersing process in the step (2) further comprises an antifoaming agent, and the antifoaming agent is silicone oil.
Preferably, the mass ratio of the inorganic salt-based grinding aid in the step (2) to the lithium salt in the lithium salt-containing suspension is 0.05% to 5%, for example, 0.05%, 0.08%, 0.1%, 0.2%, 0.3%, 0.5%, 0.8%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5%, and the like, and preferably 0.1% to 1%.
Preferably, the equipment adopted in the wet classification in the step (4) is a cyclone classifier.
Preferably, the cyclone separator can be a single cyclone separator, or can be formed by combining at least two cyclone separators.
Preferably, the cyclone classifier has a diameter of <200mm, such as 180mm, 170mm, 160mm, 150mm, 140mm, 130mm, 120mm, 100mm, 80mm, 70mm, 60mm or 50mm etc., preferably 50mm to 150 mm.
Preferably, the slurry pressure of the cyclone classifier is not less than 0.2MPa, such as 0.2MPa, 0.4MPa, 0.5MPa, 0.7MPa, 0.8MPa, 1MPa, 1.2MPa, 1.5MPa, 2MPa or 3MPa, and preferably 0.6MPa to 1.0 MPa.
In the preferable technical scheme, the diameter of the cyclone classifier and the slurry pressure of the cyclone classifier are preferably selected, so that the effect of removing large particles can be better realized, and good dispersibility among the particles is ensured.
The lithium salt obtained by the recovery method of the present invention includes: the lithium salt is used for preparing the lithium ion battery material by a solid phase method, is used for preparing all-solid electrolyte, or is used for preparing the lithium iron phosphate anode material by a hydrothermal method.
Preferably, the lithium ion battery material comprises any one of a lithium ion battery positive electrode material or a lithium ion battery negative electrode material.
In the present invention, Li is carried out on the mother liquor of the step (1) by the following two different routes, respectively, depending on the use of the obtained lithium salt+And (4) precipitating.
Preferably, when lithium salt is recycled for preparing the lithium ion battery material by the solid-phase method or preparing the all-solid-state electrolyte, the step (1) of Li is carried out on the mother liquor generated by preparing lithium iron phosphate by the hydrothermal method+The method of precipitation is route ①, which introduces Li by introducing a carbonate precipitant+Precipitation gives lithium carbonate, more specifically including: adding sodium carbonate into mother liquor generated by preparing lithium iron phosphate by a hydrothermal method to generate white lithium carbonate precipitate to obtain a first suspension;
the first suspension obtained by the preferred technical scheme is the suspension containing lithium salt in the step (2), and the final superfine lithium carbonate powder can be obtained by adopting the suspension to continuously carry out subsequent shearing, emulsifying, dispersing, wet classification, freeze drying and/or supercritical drying, wherein the particle size D90 of the superfine lithium carbonate is less than 10 mu m, the particles have good uniformity and dispersibility, and the first suspension can be used for preparing a lithium ion battery anode material and a lithium ion battery cathode material by a solid phase method or preparing an all-solid electrolyte.
Preferably, the Li is said to be in step (1) when step (1) is carried out using path ①+And (3) during precipitation, evaporating and crystallizing the filtrate obtained by filtering in the step (4)', so as to obtain sodium sulfate and realize the reutilization of lithium salt and sulfate.
Preferably, the evaporative crystallization adopts a drying mode comprising: any one of evaporation, spray drying or flash drying of an industrial waste water (MVR) evaporator.
Preferably, the Li is said to be in step (1) when step (1) is carried out using path ①+And (4) drying in a freeze drying mode in the step (4) during precipitation.
Preferably, when the lithium salt is recycled for preparing the lithium iron phosphate cathode material by the hydrothermal method, Li is carried out on the mother liquor generated in the hydrothermal method for preparing the lithium iron phosphate in the step (1)+The method of precipitation is path ②, which specifically includes:
(a) introduction of carbonate precipitant to Li+Precipitating to generate lithium carbonate, carrying out solid-liquid separation to obtain the lithium carbonate, and then adding the lithium carbonate into water under the stirring condition to form suspension;
(b) introducing carbon dioxide gas into the suspension obtained in the step (a) until all precipitates are dissolved to obtain a solution;
(c) adding phosphoric acid into the solution obtained in the step (b), and adjusting the pH value by using ammonia water;
(d) and raising the temperature to perform a precipitation reaction to generate lithium phosphate precipitate to obtain a second suspension.
The second suspension obtained by the preferred technical scheme is the suspension containing lithium salt in the step (2), and the final superfine lithium phosphate powder can be obtained by adopting the suspension to continuously carry out subsequent shearing, emulsifying, dispersing, wet-method grading, freeze drying and/or supercritical drying, wherein the particle size D90 of the superfine lithium phosphate is less than 10 mu m, the uniformity and the dispersibility of the particles are good, and the second suspension can be used for synthesizing the lithium iron phosphate cathode material by a hydrothermal method.
Preferably, the solid-liquid separation in step (a) includes any one of centrifugal filtration, ceramic membrane filtration or plate-and-frame filter pressing.
Preferably, the solution obtained after the precipitate of step (b) is completely dissolved is a lithium bicarbonate solution.
Preferably, in step (c), the phosphoric acid is added in a molar ratio of lithium to phosphorus (1-1.05):1, for example 1:1, 1.02:1, 1.03:1, 1.04:1 or 1.05:1, etc.
Preferably, step (c) adjusts the pH to 8-9, e.g., 8, 8.2, 8.5, or 9, etc.
Preferably, step (d) raises the temperature to 90-95 ℃, e.g., 90 ℃, 93 ℃, 94 ℃, or 95 ℃, etc.
Preferably, the Li is said to be in step (1) when step (1) is carried out using path ②+When in precipitation, the step (4) adopts freeze drying or supercritical dryingDrying is carried out in the manner of (1).
As a preferable embodiment of the recovery method of the present invention, the recovery method includes the steps of:
(1) ' removing impurities from mother liquor
Heating reaction liquid for preparing lithium iron phosphate by a hydrothermal method to 70-95 ℃ at the speed of 0.1-5 ℃/min, then adding sodium hydroxide or sodium hydroxide solution to adjust the pH value to 8-12, and after the reaction is finished, Cu in mother liquor2+、Co3+、Fe3+And Mn2+Separating out metal cations from the solution in the form of hydroxide precipitation, filtering, and taking filtrate to obtain mother liquor after impurity removal;
in this process Li will be excluded+Other than Cu, e.g.2+、Co3+、Fe3+And Mn2+The principle of the removal of the iso-compounds is as follows:
Cu2++OH-→Cu(OH)2↓
Fe3++OH-→Fe(OH)3↓
Co3++OH-→Cu(OH)3↓
Mn2++OH-→Mn(OH)2↓
(1) li is carried out on the mother liquor after impurity removal+Precipitation of
Adding sodium carbonate into the mother liquor after impurity removal to generate white lithium carbonate precipitate to obtain a first suspension;
in this process Li+The principle of precipitation is as follows:
Li++CO3 2-→Li2CO3↓
(2) shear emulsification dispersion
Adding an inorganic salt grinding aid into the first suspension, and performing shearing, emulsifying and dispersing at the rotating speed of 6000r/min-20000 r/min;
the inorganic salt grinding aid is any one or a mixture of at least two of sodium acetate, ammonium acetate, silicone oil, sodium thiosulfate or sodium hexametaphosphate;
(3) wet classification
Wet grading the suspension after wet grading by using a cyclone classifier, wherein the diameter of the cyclone classifier is 50-150 mm, and the pressure of the slurry is 0.6-1.0 MPa;
large particles in the waste water can be removed through wet classification treatment;
(4) ' filtering and washing the suspension after wet classification;
(4) freeze-drying the filter cake obtained by filtering in the step (4)', and recovering to obtain superfine lithium carbonate powder;
(5) and (4) carrying out evaporative crystallization on the filtrate obtained by filtering in the step (4)' to obtain sodium sulfate.
As a preferable embodiment of the recovery method of the present invention, the recovery method includes the steps of:
(1) ' removing impurities from mother liquor
Heating reaction liquid for preparing lithium iron phosphate by a hydrothermal method to 70-95 ℃ at the speed of 0.1-5 ℃/min, then adding sodium hydroxide or sodium hydroxide solution to adjust the pH value to 8-12, and after the reaction is finished, Cu in mother liquor2+、Co3+、Fe3+And Mn2+Separating out metal cations from the solution in the form of hydroxide precipitation, filtering, and taking filtrate to obtain mother liquor after impurity removal;
in this process Li will be excluded+Other than Cu, e.g.2+、Co3+、Fe3+And Mn2+The principle of the removal of the iso-compounds is as follows:
Cu2++OH-→Cu(OH)2↓
Fe3++OH-→Fe(OH)3↓
Co3++OH-→Cu(OH)3↓
Mn2++OH-→Mn(OH)2↓
(1) li is carried out on the mother liquor after impurity removal+Precipitation of
(a) Adding sodium carbonate into the mother liquor after impurity removal to generate white lithium carbonate precipitate to obtain a first suspension, carrying out solid-liquid separation to obtain lithium carbonate, and then adding the lithium carbonate into water under the stirring condition to form a suspension;
in this process Li+The principle of precipitation is as follows:
Li++CO3 2-→Li2CO3↓
(b) introducing carbon dioxide gas into the suspension obtained in the step (a) until all precipitates are dissolved to obtain a lithium bicarbonate solution;
the principle of dissolution of the lithium carbonate precipitate in this process is as follows:
Li2CO3+CO2+H2O→LiHCO3
(c) adding phosphoric acid into the solution obtained in the step (b) to ensure that the molar ratio of lithium to phosphorus is (1-1.05):1, and adjusting the pH value to 8-9 by using ammonia water;
(d) raising the temperature to 90-95 ℃, and carrying out precipitation reaction to generate lithium phosphate precipitate to obtain a second suspension;
the principle of formation of lithium phosphate precipitate in this process is as follows:
LiHCO3+H3PO4+NH3.H2O→Li3PO4↓
(2) shear emulsification dispersion
Adding inorganic salt grinding aid into the second suspension, and performing shearing, emulsifying and dispersing at the rotating speed of 6000r/min-20000 r/min;
the inorganic salt grinding aid is any one or a mixture of at least two of sodium acetate, ammonium acetate, silicone oil, sodium thiosulfate or sodium hexametaphosphate;
(3) wet classification
Wet grading the suspension after wet grading by using a cyclone classifier, wherein the diameter of the cyclone classifier is 50-150 mm, and the pressure of the slurry is 0.6-1.0 MPa;
large particles in the waste water can be removed through wet classification treatment;
(4) ' filtering and washing the suspension after wet classification;
(4) and (4) carrying out freeze drying or supercritical drying on the filter cake obtained by filtering in the step (4)', and recovering to obtain superfine lithium phosphate powder.
Compared with the prior art, the invention has the following beneficial effects:
the invention takes reaction liquid obtained after the lithium iron phosphate reaction prepared by a hydrothermal method as mother solution to carry out Li on the mother solution+After precipitation, adding an inorganic salt grinding aid, shearing, emulsifying and dispersing at a rotating speed of more than or equal to 2000r/min, and then removing large particles by wet classification, so that not only can the agglomeration of particles during reaction generation be prevented, but also the reagglomeration during subsequent wet classification and drying can be prevented, and the superfine lithium carbonate powder or lithium phosphate powder with good uniformity and good dispersibility can be obtained, and the obtained superfine lithium carbonate powder can be directly used for preparing lithium ion battery materials by a solid phase method or preparing all-solid-state electrolytes; the obtained superfine ferric phosphate powder can be directly used for synthesizing the lithium iron phosphate anode material by a hydrothermal method.
The recovery method is simple and environment-friendly, the comprehensive utilization rate of the lithium source in the lithium iron phosphate prepared by the hydrothermal method is improved, and the prepared lithium salt is ultrafine lithium carbonate powder or ultrafine lithium phosphate powder and can be directly used for preparing the lithium ion battery material, wherein the ultrafine lithium carbonate can effectively reduce local residual alkali and improve the capacity in the dry mixing process, and the ultrafine lithium phosphate can effectively improve the capacity in the lithium iron phosphate prepared by the hydrothermal method.
Detailed Description
The technical solution of the present invention is further explained by the following embodiments.
Example 1
(1) Taking 2000ml of mother liquor obtained after the reaction for preparing the lithium iron phosphate by a hydrothermal method, measuring the lithium concentration in the mother liquor by ICP to be 7.1g/L, heating the mother liquor to 70-95 ℃ at the speed of 0.1-5 ℃/min, then adding sodium hydroxide into the mother liquor, adjusting the pH value to 8-10, and then filtering to obtain a first filtrate;
(2) adding 107.5g of sodium carbonate into the first filtrate to obtain a first suspension;
(3) adding 0.35g of sodium acetate, 0.2g of silicone oil and 0.2g of sodium hexametaphosphate into the first suspension, and performing high-speed shearing, emulsification and dispersion at a rotating speed of 3000r/min by using a shearing machine to obtain a second suspension;
(4) pumping the second turbid liquid into a cyclone classifier for classification, wherein the pressure of the slurry is 0.3MPa, the diameter of the cyclone classifier is 50mm, the classification mode is that a single cyclone classifier performs classification, and removing large particles in the single cyclone classifier to obtain a third turbid liquid;
(5) and filtering and washing the third suspension, and freeze-drying at the temperature of minus 78 ℃ and the vacuum degree of 20pa to obtain superfine lithium carbonate powder which can be directly used for synthesizing lithium ion battery materials.
Example 2
(1) 11.1g of lithium carbonate obtained in example 1 was added to 2000ml of water with stirring to form a suspension a;
(2) introducing carbon dioxide gas into the suspension A until the precipitate is completely dissolved to obtain a solution B;
(3) adding 11.53g of phosphoric acid into the solution B, adding ammonia water to adjust the pH value to be 8-9, and heating to 75 ℃ to obtain a suspension C containing lithium phosphate precipitate;
(4) adding 0.2g of sodium hexametaphosphate, 0.25g of ammonium acetate and 0.05g of silicone oil into the suspension C, and carrying out high-speed shearing, emulsifying and dispersing at the rotating speed of a shearing machine of 2500r/min to obtain a suspension D;
(5) pumping the suspension D into a cyclone classifier for classification, wherein the pressure of the slurry is 0.25MPa, the diameter of the cyclone classifier is 70mm, the classification mode is combined classification, and removing large particles to obtain a suspension E;
(6) and introducing the suspension E into a supercritical drying system, heating to 374 ℃, and maintaining the pressure for 1h to obtain superfine lithium phosphate powder for preparing the matrix material of the lithium iron phosphate by a hydrothermal method.
Example 3
(1) Taking 2000ml of mother liquor obtained after the reaction for preparing the lithium iron phosphate by a hydrothermal method, measuring the lithium concentration in the mother liquor by ICP (inductively coupled plasma), heating the mother liquor to 85 ℃ at the speed of 5 ℃/min, adding sodium hydroxide into the mother liquor, adjusting the pH value to 9, and filtering to obtain first filtrate;
(2) adding 107.5g of sodium carbonate into the first filtrate to obtain a first suspension;
(3) adding 0.2g of sodium hexametaphosphate and 0.25g of sodium thiosulfate into the first suspension, and performing high-speed shearing, emulsifying and dispersing at the rotating speed of a shearing machine of 6000r/min to obtain a second suspension;
(4) pumping the second suspension into a cyclone classifier for classification, wherein the pressure of the slurry is 0.5MPa, the diameter of the cyclone classifier is 100mm, the classification mode is combined for classification, the classifier is formed by combining at least two cyclone separators, and after large particles in the classifier are removed, the third suspension is obtained;
(5) and filtering and washing the third suspension, and freeze-drying at the temperature of minus 78 ℃ and the vacuum degree of 20pa to obtain superfine lithium carbonate powder which can be directly used for synthesizing lithium ion battery materials.
Example 4
(1) 11.1g of lithium carbonate obtained in example 1 was added to 2000ml of water with stirring to form a suspension a;
(2) introducing carbon dioxide gas into the suspension A until the precipitate is completely dissolved to obtain a solution B;
(3) adding 11.53g of phosphoric acid into the solution B, adding ammonia water to adjust the pH value to be 8-9, and heating to 75 ℃ to obtain a suspension C containing lithium phosphate;
(4) adding 0.2g of sodium hexametaphosphate, 0.25g of ammonium acetate and 0.05g of silicone oil into the suspension C, and carrying out high-speed shearing, emulsifying and dispersing at the rotating speed of a shearing machine of 8000r/min to obtain a suspension D;
(5) pumping the suspension D into a cyclone classifier for classification, wherein the pressure of slurry is 0.65MPa, the diameter of the cyclone classifier is 120mm, the classification mode is that a single cyclone classifier performs classification, and removing large particles to obtain a suspension E;
(6) and introducing the suspension E into a supercritical drying system, heating to 374 ℃, and maintaining the pressure for 1h to obtain superfine lithium phosphate powder for preparing the matrix material of the lithium iron phosphate by a hydrothermal method.
Example 5
The procedure of example 1 was repeated except that sodium acetate was replaced with sodium thiosulfate, the rotational speed of the shearing machine was adjusted to 10000r/min, the slurry pressure was adjusted to 0.5MPa, and the diameter of the cyclone classifier was replaced with 60 mm.
The superfine lithium carbonate powder obtained in the embodiment can be directly used for synthesizing lithium ion battery materials.
Example 6
The procedure of example 2 was repeated except that sodium hexametaphosphate was replaced with sodium thiosulfate, the rotational speed of the shearing machine was adjusted to 18000r/min, the slurry pressure was adjusted to 1MPa, and the cyclone classifier diameter was replaced with 175 mm.
The superfine lithium phosphate powder obtained in the embodiment is used for preparing a matrix material of lithium iron phosphate by a hydrothermal method.
Comparative example 1
The procedure was as in example 1 except that step (5) was replaced by drying in an oven.
In the conventional oven drying process, the dispersion medium volatilizes to cause re-agglomeration of solid particles, so that the dispersibility is poor.
Comparative example 2
The procedure was as in example 1 except that the steps (3) and (4) were not carried out.
The comparative example did not have the shear emulsion dispersion and wet classification materials, so that agglomeration occurred as lithium carbonate was generated and lithium carbonate had poor uniformity.
Comparative example 3
The procedure of example 1 was repeated except that the rotation speed in step (3) was adjusted to 500 r/min.
In comparative example 3, the rotating speed of the shearing, emulsifying and dispersing is too low, and the functions of sodium acetate, silicone oil and sodium hexametaphosphate as grinding aids cannot be well played.
The lithium carbonate is agglomerated when being generated, and the dispersibility is poor.
As can be seen from examples 1 to 6, in the present invention, Li was added to a reaction solution obtained by hydrothermal preparation of lithium iron phosphate as a mother solution+After precipitation, inorganic salt grinding aid is added to carry out shearing emulsification dispersion under the condition of the rotating speed of more than or equal to 2000r/min, and then large particles are removed by wet classification, so that not only can the agglomeration of the particles during reaction generation be prevented, but also the re-agglomeration during subsequent wet classification and drying can be prevented, and the superfine lithium carbonate powder or lithium phosphate powder with good uniformity and good dispersibility can be obtained. While comparative examples 1-3 did not employ the technique of the present inventionAccording to the scheme, the obtained product has poor dispersity and uniformity, and cannot achieve the technical effect claimed by the invention.
The products of the examples and comparative examples were particle size characterized and the results are shown in table 1.
TABLE 1
The ultrafine lithium carbonate powders of example 1, example 3, example 5 and comparative examples 1 to 3 were used to prepare a ternary positive electrode material (abbreviated as NCM622 material) by the following specific steps: and mixing the lithium carbonate and the precursor for 2 hours by a three-dimensional mixer according to the lithium/metal molar ratio of Li/Me 1.05, placing the mixture in an oxygen atmosphere, and sintering the mixture for 10 hours at 700 ℃ to obtain the ternary cathode material.
The carbon-coated lithium iron phosphate positive electrode material (LFP material for short) was prepared using the lithium phosphate powders of example 2, example 4, and example 6, and the specific steps were as follows: respectively weighing lithium phosphate and ferrous sulfate according to a molar ratio of 1:1, transferring the lithium phosphate into a high-pressure reaction kettle containing a ferrous sulfate saturated solution, introducing nitrogen for oxygen removal, heating to 200 ℃ under high-speed stirring, preserving heat for 4 hours, filtering to obtain lithium iron phosphate powder, mixing the lithium iron phosphate powder with glucose according to a mass ratio of 100:9, and sintering at 700 ℃ for 10 hours to obtain the carbon-coated lithium iron phosphate.
The button cell is prepared by adopting the ternary cathode material and the carbon-coated lithium iron phosphate as the cathode material of the lithium ion battery, and the method comprises the following specific steps:
weighing the positive electrode material, the conductive agent and the binder according to the mass ratio of 8:1:1, mixing to prepare slurry, dispersing the solvent, coating the dispersed solution on an aluminum foil current collector, and baking the aluminum foil current collector for 2 to 6 hours at 85 ℃ to prepare a wafer; the 2032 type button cell is made by using lithium plate as cathode.
Electrochemical performance tests were performed on button cells using each of the examples and comparative examples, and the results are shown in table 2.
TABLE 2
The applicant states that the present invention is illustrated in detail by the above examples, but the present invention is not limited to the above detailed methods, i.e. it is not meant that the present invention must rely on the above detailed methods for its implementation. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.
Claims (10)
1. A method for recovering lithium salt from a mother liquor generated in preparation of lithium iron phosphate by a hydrothermal method is characterized by comprising the following steps:
(1) li is carried out on mother solution generated by preparing lithium iron phosphate by hydrothermal method+Precipitating to obtain a suspension containing lithium salt;
(2) then adding inorganic salt grinding aid into the obtained lithium salt-containing suspension for shearing, emulsifying and dispersing under the condition of the rotating speed of more than or equal to 2000 r/min;
(3) wet classification;
(4) and (3) drying by adopting a freeze drying and/or supercritical drying mode, and recovering to obtain the lithium salt.
2. The recycling method of claim 1, wherein the mother liquor generated in the hydrothermal preparation of lithium iron phosphate contains Li as a main cation+The main anion being SO4 2-；
Preferably, in the mother liquor generated by preparing lithium iron phosphate by the hydrothermal method, Li+The concentration is 0-1.2g/100 g;
preferably, the mother solution generated in the preparation of lithium iron phosphate by the hydrothermal method is subjected to neutralizationThe ions also including Fe2+And/or Fe3+(ii) a The anion also comprising PO4 3-、HPO4 2-Or H2PO4 -Any one or a combination of at least two of;
preferably, in the mother liquor generated in the preparation of lithium iron phosphate by the hydrothermal method, the cations further include doped cations, and the doped cations include Cu2+、Co3+、Ni2+Or Mn2+Any one or a combination of at least two of them.
3. The recycling method according to claim 1 or 2, further comprising: in Li+Step (1)' is performed before precipitation: the mother liquor is subjected to impurity removal so as to remove Li+Removing other cations from the mother liquor, and taking the filtrate to obtain the mother liquor after impurity removal;
preferably, the step (1)' the specific step of removing impurities comprises: heating mother liquor generated by preparing lithium iron phosphate by a hydrothermal method, adding alkali to adjust the pH value, filtering after the reaction is finished, and taking filtrate to obtain the mother liquor after impurity removal;
preferably, during the impurity removal of the step (1)', the heating is carried out to the temperature of 70-95 ℃;
preferably, in the impurity removing process in the step (1)', the temperature rise speed during heating is 0.1 ℃/min-5 ℃/min;
preferably, in the process of removing impurities in the step (1)', the alkali is sodium hydroxide powder or sodium hydroxide solution;
preferably, during the impurity removal in the step (1)', the pH value is adjusted to 8-12;
preferably, in the impurity removing process of step (1)', the filtration method comprises any one of centrifugal filtration, ceramic membrane filtration or plate-and-frame filter pressing.
4. A recycling method according to any one of claims 1 to 3, characterized in that it further comprises: after wet fractionation, before freeze-drying and/or supercritical drying, step (4)': filtering and washing the solid obtained by filtering, or concentrating, filtering and washing the solid obtained by filtering.
5. The recovery method as claimed in any one of claims 1 to 4, wherein the inorganic salt grinding aid in step (2) is any one or a mixture of at least two of sodium acetate, ammonium acetate, sodium thiosulfate or sodium hexametaphosphate;
preferably, the shearing, emulsifying and dispersing process in the step (2) further comprises a defoaming agent, wherein the defoaming agent is silicone oil;
preferably, the mass ratio of the inorganic salt grinding aid in the step (2) to the lithium salt in the lithium salt-containing suspension is 0.05% -5%, and preferably 0.1% -1%;
preferably, the equipment adopted for the shearing, emulsifying and dispersing in the step (3) is a high-speed shearing, emulsifying and dispersing agent, and the rotating speed of the shearing, emulsifying and dispersing is preferably 6000r/min-20000 r/min;
preferably, the equipment adopted in the wet classification in the step (4) is a cyclone classifier;
preferably, the cyclone separator is a single cyclone separator or is formed by combining at least two cyclone separators;
preferably, the cyclone classifier has a diameter <200mm, preferably 50mm-150 mm;
preferably, the slurry pressure of the cyclone classifier is more than or equal to 0.2MPa, and preferably 0.6MPa-1.0 MPa.
6. The recovery method according to any one of claims 1 to 5, wherein the use of the lithium salt comprises: the lithium salt is used for preparing the lithium ion battery material by a solid phase method, is used for preparing all-solid electrolyte, or is used for preparing the lithium iron phosphate anode material by a hydrothermal method;
preferably, the lithium ion battery material comprises any one of a lithium ion battery positive electrode material or a lithium ion battery negative electrode material.
7. The method of claim 6, wherein the lithium salt is recovered when the lithium salt is used in a solid phase process for preparing lithium ionWhen the cell material or the all-solid-state electrolyte is prepared, the Li is carried out on the mother solution generated by preparing the lithium iron phosphate by the hydrothermal method in the step (1)+The method of precipitation is route ①, which introduces Li by introducing a carbonate precipitant+Precipitation gives lithium carbonate, more specifically including: adding sodium carbonate into mother liquor generated by preparing lithium iron phosphate by a hydrothermal method to generate white lithium carbonate precipitate to obtain a first suspension;
preferably, the Li is said to be in step (1) when step (1) is carried out using path ①+During precipitation, evaporating and crystallizing the filtrate obtained by filtering in the step (4)' to obtain sodium sulfate;
preferably, the evaporative crystallization adopts a drying mode comprising: any one of industrial wastewater MVR evaporator evaporation, spray drying or flash evaporation drying;
preferably, the Li is said to be in step (1) when step (1) is carried out using path ①+And (4) drying in a freeze drying mode in the step (4) during precipitation.
8. The recycling method according to claim 6, wherein when the lithium salt is recycled for hydrothermal preparation of the lithium iron phosphate cathode material, Li is applied to the mother liquor generated in step (1) hydrothermal preparation of lithium iron phosphate+The method of precipitation is path ②, which specifically includes:
(a) introduction of carbonate precipitant to Li+Precipitating to generate lithium carbonate, carrying out solid-liquid separation to obtain the lithium carbonate, and then adding the lithium carbonate into water under the stirring condition to form suspension;
(b) introducing carbon dioxide gas into the suspension obtained in the step (a) until all precipitates are dissolved to obtain a solution;
(c) adding phosphoric acid into the solution obtained in the step (b), and adjusting the pH value by using ammonia water;
(d) raising the temperature, and carrying out precipitation reaction to generate lithium phosphate precipitate to obtain a second suspension;
preferably, the solid-liquid separation mode in the step (a) comprises any one of centrifugal filtration, ceramic membrane filtration or plate-and-frame filter pressing;
preferably, the solution obtained after the precipitate in the step (b) is completely dissolved is a lithium bicarbonate solution;
preferably, the phosphoric acid of step (c) is added in a molar ratio of lithium to phosphorus (1-1.05): 1;
preferably, step (c) adjusts the pH to 8-9;
preferably, step (d) raises the temperature to 90 ℃ -95 ℃;
preferably, the Li is said to be in step (1) when step (1) is carried out using path ②+And (4) during precipitation, drying in a freeze drying or supercritical drying mode in the step (4).
9. A recycling method according to any one of claims 1 to 8, characterized in that it comprises the following steps:
(1) ' removing impurities from mother liquor
Heating a reaction solution for preparing lithium iron phosphate by a hydrothermal method to 70-95 ℃ at the speed of 0.1-5 ℃/min, then adding sodium hydroxide or a sodium hydroxide solution to adjust the pH value to 8-12, filtering after the reaction is finished, and taking a filtrate to obtain a mother solution after impurity removal;
(1) li is carried out on the mother liquor after impurity removal+Precipitation of
Adding sodium carbonate into the mother liquor after impurity removal to generate white lithium carbonate precipitate to obtain a first suspension;
(2) shear emulsification dispersion
Adding an inorganic salt grinding aid into the first suspension, and performing shearing, emulsifying and dispersing at the rotating speed of 6000r/min-20000 r/min;
the inorganic salt grinding aid is any one or a mixture of at least two of sodium acetate, ammonium acetate, silicone oil, sodium thiosulfate or sodium hexametaphosphate;
(3) wet classification
Wet grading the suspension after wet grading by using a cyclone classifier, wherein the diameter of the cyclone classifier is 50-150 mm, and the pressure of the slurry is 0.6-1.0 MPa;
(4) ' filtering and washing the suspension after wet classification;
(4) freeze-drying the filter cake obtained by filtering in the step (4)', and recovering to obtain superfine lithium carbonate powder;
(5) and (4) carrying out evaporative crystallization on the filtrate obtained by filtering in the step (4)' to obtain sodium sulfate.
10. A recycling method according to any one of claims 1 to 8, characterized in that it comprises the following steps:
(1) ' removing impurities from mother liquor
Heating a reaction solution for preparing lithium iron phosphate by a hydrothermal method to 70-95 ℃ at the speed of 0.1-5 ℃/min, then adding sodium hydroxide or a sodium hydroxide solution to adjust the pH value to 8-12, filtering after the reaction is finished, and taking a filtrate to obtain a mother solution after impurity removal;
(1) li is carried out on the mother liquor after impurity removal+Precipitation of
(a) Adding sodium carbonate into the mother liquor after impurity removal to generate white lithium carbonate precipitate to obtain a first suspension, carrying out solid-liquid separation to obtain lithium carbonate, and then adding the lithium carbonate into water under the stirring condition to form a suspension;
(b) introducing carbon dioxide gas into the suspension obtained in the step (a) until all precipitates are dissolved to obtain a lithium bicarbonate solution;
(c) adding phosphoric acid into the solution obtained in the step (b) to ensure that the molar ratio of lithium to phosphorus is (1-1.05):1, and adjusting the pH value to 8-9 by using ammonia water;
(d) raising the temperature to 90-95 ℃, and carrying out precipitation reaction to generate lithium phosphate precipitate to obtain a second suspension;
(2) shear emulsification dispersion
Adding inorganic salt grinding aid into the second suspension, and performing shearing, emulsifying and dispersing at the rotating speed of 6000r/min-20000 r/min;
the inorganic salt grinding aid is any one or a mixture of at least two of sodium acetate, ammonium acetate, silicone oil, sodium thiosulfate or sodium hexametaphosphate;
(3) wet classification
Wet grading the suspension after wet grading by using a cyclone classifier, wherein the diameter of the cyclone classifier is 50-150 mm, and the pressure of the slurry is 0.6-1.0 MPa;
(4) ' filtering and washing the suspension after wet classification;
(4) and (4) carrying out freeze drying or supercritical drying on the filter cake obtained by filtering in the step (4)', and recovering to obtain superfine lithium phosphate powder.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112408437A (en) * | 2020-11-19 | 2021-02-26 | 江西天新药业股份有限公司 | Method for recovering lithium salt |
| CN115818608A (en) * | 2022-08-01 | 2023-03-21 | 芜湖天弋能源科技有限公司 | LiFePO 4 Separation and purification method of |
Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102030320A (en) * | 2009-09-25 | 2011-04-27 | 上海中锂实业有限公司 | Preparation method of lithium phosphate |
| CN102432045A (en) * | 2011-09-26 | 2012-05-02 | 江苏海龙锂业科技有限公司 | Preparation method of ultra-high purity lithium carbonate |
| CN102897803A (en) * | 2012-10-22 | 2013-01-30 | 四川天齐锂业股份有限公司 | Method for recycling mother solution generated in lithium iron phosphate preparation method based on liquid phase method |
| CN203139923U (en) * | 2013-03-15 | 2013-08-21 | 温州百力仕龙野轻工设备有限公司 | High-shear dispersing emulsification pump |
| CN103962251A (en) * | 2014-04-18 | 2014-08-06 | 松阳县中奇环境工程有限公司 | Shearing emulsifying smashing device for processing materials containing ferrites |
| CN104857931A (en) * | 2015-05-14 | 2015-08-26 | 江苏玖川纳米材料科技有限公司 | Production method of printing and dyeing wastewater adsorption, flocculation and photocatalysis materials |
| CN106586999A (en) * | 2015-10-18 | 2017-04-26 | 深圳市沃特玛电池有限公司 | Method for preparing lithium iron phosphate precursor by virtue of vacuum freeze drying |
| CN106800305A (en) * | 2017-01-11 | 2017-06-06 | 浙江海虹控股集团有限公司 | A kind of method that multistep processes prepares battery-level lithium carbonate |
| CN107265485A (en) * | 2017-07-05 | 2017-10-20 | 武汉理工大学 | Fluorination calcination process spodumene puies forward the method that lithium prepares lithium carbonate |
| CN107915239A (en) * | 2017-12-08 | 2018-04-17 | 天齐锂业股份有限公司 | A kind of method for recycling hydro-thermal method production LiFePO4 waste liquid and preparing high-purity sulphuric acid lithium |
| CN107986301A (en) * | 2017-12-27 | 2018-05-04 | 江西赣锋锂业股份有限公司 | A kind of method using battery-level lithium carbonate sinker mother liquor production LITHIUM BATTERY lithium hydroxide |
| CN108134150A (en) * | 2017-12-20 | 2018-06-08 | 山东高佳新能源有限公司 | The method of valuable element in hydro-thermal synthetical recovery waste lithium iron phosphate positive electrode |
-
2018
- 2018-07-11 CN CN201810757777.0A patent/CN110713197B/en active Active
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102030320A (en) * | 2009-09-25 | 2011-04-27 | 上海中锂实业有限公司 | Preparation method of lithium phosphate |
| CN102432045A (en) * | 2011-09-26 | 2012-05-02 | 江苏海龙锂业科技有限公司 | Preparation method of ultra-high purity lithium carbonate |
| CN102897803A (en) * | 2012-10-22 | 2013-01-30 | 四川天齐锂业股份有限公司 | Method for recycling mother solution generated in lithium iron phosphate preparation method based on liquid phase method |
| CN203139923U (en) * | 2013-03-15 | 2013-08-21 | 温州百力仕龙野轻工设备有限公司 | High-shear dispersing emulsification pump |
| CN103962251A (en) * | 2014-04-18 | 2014-08-06 | 松阳县中奇环境工程有限公司 | Shearing emulsifying smashing device for processing materials containing ferrites |
| CN104857931A (en) * | 2015-05-14 | 2015-08-26 | 江苏玖川纳米材料科技有限公司 | Production method of printing and dyeing wastewater adsorption, flocculation and photocatalysis materials |
| CN106586999A (en) * | 2015-10-18 | 2017-04-26 | 深圳市沃特玛电池有限公司 | Method for preparing lithium iron phosphate precursor by virtue of vacuum freeze drying |
| CN106800305A (en) * | 2017-01-11 | 2017-06-06 | 浙江海虹控股集团有限公司 | A kind of method that multistep processes prepares battery-level lithium carbonate |
| CN107265485A (en) * | 2017-07-05 | 2017-10-20 | 武汉理工大学 | Fluorination calcination process spodumene puies forward the method that lithium prepares lithium carbonate |
| CN107915239A (en) * | 2017-12-08 | 2018-04-17 | 天齐锂业股份有限公司 | A kind of method for recycling hydro-thermal method production LiFePO4 waste liquid and preparing high-purity sulphuric acid lithium |
| CN108134150A (en) * | 2017-12-20 | 2018-06-08 | 山东高佳新能源有限公司 | The method of valuable element in hydro-thermal synthetical recovery waste lithium iron phosphate positive electrode |
| CN107986301A (en) * | 2017-12-27 | 2018-05-04 | 江西赣锋锂业股份有限公司 | A kind of method using battery-level lithium carbonate sinker mother liquor production LITHIUM BATTERY lithium hydroxide |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112408437A (en) * | 2020-11-19 | 2021-02-26 | 江西天新药业股份有限公司 | Method for recovering lithium salt |
| CN112408437B (en) * | 2020-11-19 | 2023-03-28 | 江西天新药业股份有限公司 | Method for recovering lithium salt |
| CN115818608A (en) * | 2022-08-01 | 2023-03-21 | 芜湖天弋能源科技有限公司 | LiFePO 4 Separation and purification method of |
| CN115818608B (en) * | 2022-08-01 | 2024-02-23 | 芜湖天弋能源科技有限公司 | LiFePO 4 Is separated and purified by the method |
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