CN116409769A - Method for preparing battery-grade ferric phosphate and lithium carbonate by using crude lithium phosphate - Google Patents
Method for preparing battery-grade ferric phosphate and lithium carbonate by using crude lithium phosphate Download PDFInfo
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- 229910001386 lithium phosphate Inorganic materials 0.000 title claims abstract description 78
- TWQULNDIKKJZPH-UHFFFAOYSA-K trilithium;phosphate Chemical compound [Li+].[Li+].[Li+].[O-]P([O-])([O-])=O TWQULNDIKKJZPH-UHFFFAOYSA-K 0.000 title claims abstract description 78
- WBJZTOZJJYAKHQ-UHFFFAOYSA-K iron(3+) phosphate Chemical compound [Fe+3].[O-]P([O-])([O-])=O WBJZTOZJJYAKHQ-UHFFFAOYSA-K 0.000 title claims abstract description 69
- 238000000034 method Methods 0.000 title claims abstract description 66
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 title claims abstract description 63
- 229910052808 lithium carbonate Inorganic materials 0.000 title claims abstract description 63
- 239000005955 Ferric phosphate Substances 0.000 title claims abstract description 48
- 229940032958 ferric phosphate Drugs 0.000 title claims abstract description 48
- 229910000399 iron(III) phosphate Inorganic materials 0.000 title claims abstract description 48
- 229910052744 lithium Inorganic materials 0.000 claims abstract description 58
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims abstract description 57
- 238000000605 extraction Methods 0.000 claims abstract description 34
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims abstract description 32
- 239000011574 phosphorus Substances 0.000 claims abstract description 32
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 32
- 239000012535 impurity Substances 0.000 claims abstract description 26
- 239000007788 liquid Substances 0.000 claims abstract description 22
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 claims abstract description 14
- 238000001914 filtration Methods 0.000 claims abstract description 14
- 238000005984 hydrogenation reaction Methods 0.000 claims abstract description 14
- 230000001590 oxidative effect Effects 0.000 claims abstract description 10
- 230000001376 precipitating effect Effects 0.000 claims abstract description 10
- 238000001035 drying Methods 0.000 claims abstract description 9
- 238000000227 grinding Methods 0.000 claims abstract description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 28
- 238000006243 chemical reaction Methods 0.000 claims description 26
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 25
- 229910000398 iron phosphate Inorganic materials 0.000 claims description 21
- 238000001556 precipitation Methods 0.000 claims description 20
- 238000007127 saponification reaction Methods 0.000 claims description 18
- 238000000746 purification Methods 0.000 claims description 11
- 239000002253 acid Substances 0.000 claims description 8
- 238000000354 decomposition reaction Methods 0.000 claims description 8
- 239000007800 oxidant agent Substances 0.000 claims description 8
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims description 7
- 239000012074 organic phase Substances 0.000 claims description 7
- 230000001105 regulatory effect Effects 0.000 claims description 5
- 150000003839 salts Chemical class 0.000 claims description 4
- 229910052760 oxygen Inorganic materials 0.000 claims description 3
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 claims description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 2
- 239000001301 oxygen Substances 0.000 claims description 2
- DHCDFWKWKRSZHF-UHFFFAOYSA-N sulfurothioic S-acid Chemical compound OS(O)(=O)=S DHCDFWKWKRSZHF-UHFFFAOYSA-N 0.000 claims description 2
- 230000003647 oxidation Effects 0.000 claims 1
- 238000007254 oxidation reaction Methods 0.000 claims 1
- 238000000926 separation method Methods 0.000 abstract description 13
- 238000004519 manufacturing process Methods 0.000 abstract description 4
- 239000000243 solution Substances 0.000 description 81
- 239000011575 calcium Substances 0.000 description 21
- 239000000047 product Substances 0.000 description 21
- 229910052782 aluminium Inorganic materials 0.000 description 20
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 18
- -1 alkyl phosphonic acid Chemical compound 0.000 description 17
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 16
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 14
- 229910001416 lithium ion Inorganic materials 0.000 description 14
- 229910019142 PO4 Inorganic materials 0.000 description 13
- 229910052742 iron Inorganic materials 0.000 description 13
- 239000010452 phosphate Substances 0.000 description 13
- 239000007787 solid Substances 0.000 description 13
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 description 12
- 238000011084 recovery Methods 0.000 description 11
- 229910001448 ferrous ion Inorganic materials 0.000 description 10
- 238000005406 washing Methods 0.000 description 10
- BHPQYMZQTOCNFJ-UHFFFAOYSA-N Calcium cation Chemical compound [Ca+2] BHPQYMZQTOCNFJ-UHFFFAOYSA-N 0.000 description 9
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 9
- 229910052791 calcium Inorganic materials 0.000 description 9
- 229910001424 calcium ion Inorganic materials 0.000 description 9
- 239000000706 filtrate Substances 0.000 description 9
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 7
- WMFOQBRAJBCJND-UHFFFAOYSA-M Lithium hydroxide Chemical compound [Li+].[OH-] WMFOQBRAJBCJND-UHFFFAOYSA-M 0.000 description 6
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 6
- 239000011790 ferrous sulphate Substances 0.000 description 6
- 235000003891 ferrous sulphate Nutrition 0.000 description 6
- 239000012065 filter cake Substances 0.000 description 6
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 description 6
- 229910000359 iron(II) sulfate Inorganic materials 0.000 description 6
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 6
- 239000003350 kerosene Substances 0.000 description 5
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 4
- 239000006227 byproduct Substances 0.000 description 4
- 230000001276 controlling effect Effects 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 4
- 150000002500 ions Chemical class 0.000 description 4
- KWGKDLIKAYFUFQ-UHFFFAOYSA-M lithium chloride Chemical compound [Li+].[Cl-] KWGKDLIKAYFUFQ-UHFFFAOYSA-M 0.000 description 4
- 239000011777 magnesium Substances 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 239000012452 mother liquor Substances 0.000 description 4
- 239000012071 phase Substances 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 3
- ILRRQNADMUWWFW-UHFFFAOYSA-K aluminium phosphate Chemical compound O1[Al]2OP1(=O)O2 ILRRQNADMUWWFW-UHFFFAOYSA-K 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N iron oxide Inorganic materials [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 3
- 239000011259 mixed solution Substances 0.000 description 3
- 239000002244 precipitate Substances 0.000 description 3
- 230000035484 reaction time Effects 0.000 description 3
- 239000002893 slag Substances 0.000 description 3
- 239000011734 sodium Substances 0.000 description 3
- 238000000967 suction filtration Methods 0.000 description 3
- 235000010215 titanium dioxide Nutrition 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 2
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 229910000019 calcium carbonate Inorganic materials 0.000 description 2
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 2
- 239000000920 calcium hydroxide Substances 0.000 description 2
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 2
- 229910002091 carbon monoxide Inorganic materials 0.000 description 2
- 239000003085 diluting agent Substances 0.000 description 2
- 239000000284 extract Substances 0.000 description 2
- 229910021645 metal ion Inorganic materials 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000005191 phase separation Methods 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 238000004537 pulping Methods 0.000 description 2
- 238000004064 recycling Methods 0.000 description 2
- CHQMHPLRPQMAMX-UHFFFAOYSA-L sodium persulfate Chemical compound [Na+].[Na+].[O-]S(=O)(=O)OOS([O-])(=O)=O CHQMHPLRPQMAMX-UHFFFAOYSA-L 0.000 description 2
- 239000002699 waste material Substances 0.000 description 2
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- VTLYFUHAOXGGBS-UHFFFAOYSA-N Fe3+ Chemical compound [Fe+3] VTLYFUHAOXGGBS-UHFFFAOYSA-N 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- JLVVSXFLKOJNIY-UHFFFAOYSA-N Magnesium ion Chemical compound [Mg+2] JLVVSXFLKOJNIY-UHFFFAOYSA-N 0.000 description 1
- 229910002651 NO3 Inorganic materials 0.000 description 1
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 1
- OEMGCAOEZNBNAE-UHFFFAOYSA-N [P].[Li] Chemical compound [P].[Li] OEMGCAOEZNBNAE-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 235000011114 ammonium hydroxide Nutrition 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 239000010405 anode material Substances 0.000 description 1
- 239000008346 aqueous phase Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000012267 brine Substances 0.000 description 1
- BRPQOXSCLDDYGP-UHFFFAOYSA-N calcium oxide Chemical compound [O-2].[Ca+2] BRPQOXSCLDDYGP-UHFFFAOYSA-N 0.000 description 1
- 239000000292 calcium oxide Substances 0.000 description 1
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 1
- 238000000975 co-precipitation Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 239000008367 deionised water Substances 0.000 description 1
- 229910021641 deionized water Inorganic materials 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 229960002089 ferrous chloride Drugs 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 229910000041 hydrogen chloride Inorganic materials 0.000 description 1
- IXCSERBJSXMMFS-UHFFFAOYSA-N hydrogen chloride Substances Cl.Cl IXCSERBJSXMMFS-UHFFFAOYSA-N 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- NMCUIPGRVMDVDB-UHFFFAOYSA-L iron dichloride Chemical compound Cl[Fe]Cl NMCUIPGRVMDVDB-UHFFFAOYSA-L 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 238000002386 leaching Methods 0.000 description 1
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- ZLNQQNXFFQJAID-UHFFFAOYSA-L magnesium carbonate Chemical compound [Mg+2].[O-]C([O-])=O ZLNQQNXFFQJAID-UHFFFAOYSA-L 0.000 description 1
- 239000001095 magnesium carbonate Substances 0.000 description 1
- 229910000021 magnesium carbonate Inorganic materials 0.000 description 1
- 229910001425 magnesium ion Inorganic materials 0.000 description 1
- 239000010413 mother solution Substances 0.000 description 1
- 238000006386 neutralization reaction Methods 0.000 description 1
- 230000006911 nucleation Effects 0.000 description 1
- 238000010899 nucleation Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000036632 reaction speed Effects 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 229910000030 sodium bicarbonate Inorganic materials 0.000 description 1
- 235000017557 sodium bicarbonate Nutrition 0.000 description 1
- 229910000029 sodium carbonate Inorganic materials 0.000 description 1
- AKHNMLFCWUSKQB-UHFFFAOYSA-L sodium thiosulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=S AKHNMLFCWUSKQB-UHFFFAOYSA-L 0.000 description 1
- 235000019345 sodium thiosulphate Nutrition 0.000 description 1
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 239000002912 waste gas Substances 0.000 description 1
Images
Classifications
-
- 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
- C01B25/37—Phosphates of heavy metals
- C01B25/375—Phosphates of heavy metals of iron
-
- 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
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/80—Compositional purity
-
- 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
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Manufacture And Refinement Of Metals (AREA)
Abstract
The invention discloses a method for preparing battery-grade ferric phosphate and lithium carbonate by using crude lithium phosphate. Grinding, dissolving and filtering crude lithium phosphate in sequence to obtain crude lithium phosphate solution; separation of Al from crude lithium phosphate solution by extraction 3+ And Ca 2+ Oxidizing and precipitating phosphorus in the raffinate to obtain hydrated ferric phosphate and phosphorus-precipitated liquid, and drying the hydrated ferric phosphate to obtain battery-grade ferric phosphate; and (3) deeply removing impurities from the phosphorus-precipitated solution, and precipitating lithium through carbonate to obtain crude lithium carbonate, wherein the crude lithium carbonate is purified through a hydrogenation method to obtain the battery-grade lithium carbonate. The method can comprehensively recover the phosphorus and the lithium in the crude lithium phosphate, and simultaneously obtain the battery-grade ferric phosphate and the lithium carbonate, and has the advantages of simple operation, short flow, low cost and contribution to mass production.
Description
Technical Field
The invention relates to a method for recycling crude lithium phosphate, in particular to a method for preparing battery-grade ferric phosphate and lithium carbonate by utilizing crude lithium phosphate, and belongs to the technical field of lithium resource recycling.
Background
The low-concentration lithium solution can be produced after lithium ore decomposition, waste lithium ion battery recovery and salt lake brine extraction to precipitate lithium carbonate. In the industrial production process, the part of low-concentration lithium solution is generally precipitated and concentrated by adding phosphate to obtain crude lithium phosphate, and the crude lithium phosphate obtained in the way cannot be directly used as a lithium source for the next step, because two points exist: on the one hand, lithium carbonate contains a large amount of metal impurity ions (such as Mn, mg, ca, zn, al, ti, K, na, etc.), and the content of each metal varies greatly according to the difference of raw materials, on the other hand, lithium phosphate has low reactivity due to phosphate radicals with high stability, so that the purpose of utilization is difficult to achieve by simple separation and purification, and the separation difficulty coefficient of main components and metal impurity ions is large due to complex components in lithium carbonate slag.
Industrial scale crude lithium phosphate refining process: dissolving crude lithium phosphate in a dilute hydrochloric acid solution, adding a calcium-containing compound (such as calcium oxide, calcium hydroxide and calcium carbonate) for conversion reaction to obtain a lithium chloride mother solution and calcium hydrophosphate precipitate, and carrying out solid-liquid separation step by step to realize lithium and phosphorus recovery. The process recovers lithium and phosphorus, but has large acid and alkali consumption, and the involved process releases heat severely, so that hydrogen chloride gas overflows, and the operation condition is extremely bad. In addition, the cost of the subsequent purification and impurity removal process of the lithium chloride mother liquor is increased due to the introduction of calcium, and a large amount of low-added-value calcium hydrophosphate slag which is difficult to treat is also generated. Thus, currently coarse lithium phosphate utilization is mainly focused on preparing lithium products, such as chinese patent CN106586995A and chinese patent CN108928839a, not only is lithium recovery hopeful to be further improved, but also by-products generated in the lithium recovery process present potential environmental risks. For example, chinese patent CN109264748B discloses a process for preparing battery grade lithium carbonate and iron phosphate by recovering lithium phosphorus from crude lithium phosphate, which specifically comprises processes of pulping crude lithium phosphate, preparing iron phosphate, preparing lithium carbonate, and the like, although the recovery of phosphorus and lithium is comprehensively considered in the technology of this patent, there are the following disadvantages: (1) The lithium phosphate pulping process does not adequately account for insoluble and poorly soluble impurities; (2) The crude lithium phosphate contains a certain amount of Al, based on aluminum phosphate (K sp ＝9.84×10 ～21 ) And hydrated ferric phosphate (K) sp ＝1.30×10 ～22 ) The chemical structure of the aluminum phosphate is similar, and the aluminum phosphate coprecipitation is accompanied in the synthesis process of the hydrated ferric phosphate, so that the purpose of separating impurity aluminum is achieved only by regulating and controlling the stirring speed, which is obviously difficult to realize; (3) The water content of the synthesized hydrated ferric phosphate is greatly increased under the conditions of ferric iron source and pH=2-3, so that most of lithium can only be recovered from washing water, the content of washing water lithium is low, the subsequent lithium recovery cost and recovery difficulty are increased, and the economical efficiency is reduced; in addition, the filtration performance of hydrated iron phosphate is poor. Chinese patent CN110342483a suffers from similar problems (ph=1.8-3.0). In addition, chinese patent CN113802017A discloses a method for separating and recovering aluminum in acid leaching solution of waste lithium iron phosphate battery anode material by an extraction method, wherein the aluminum in a Li-Fe-P-Al system is extracted by an organic phase containing a long-chain alkyl phosphonic acid extractant, so that a better separation effect is obtained, but the concentration range of the aluminum in a solution system suitable for the technology of the patent is 0.5-12.8 g/L, the concentration of lithium ions is 3.1-15.7 g/L, namely the molar ratio of Li/Al is 0.95-120; and it adopts P204 after saponification to Li + The method has certain extraction capacity, the content of aluminum in crude lithium phosphate is generally 0.05% -0.4%, the content of lithium is 15.0% -17.0%, the molar ratio of Li/Al is 140-1330, for a solution system with high Li/Al molar ratio, more than 10% of lithium can be extracted in the process of extracting and separating aluminum by using saponified P204, the loss is large, and although the extracted lithium can be recovered after back extraction, the concentration of lithium in the solution can be reduced, so that the subsequent lithium precipitation process is not facilitated.
Disclosure of Invention
Aiming at the defects of the prior art on the utilization technology of crude lithium phosphate, the invention aims to provide a method for preparing battery-grade ferric phosphate and lithium carbonate by utilizing the crude lithium phosphate, and the method can comprehensively recover phosphorus and lithium in the crude lithium phosphate and simultaneously obtain the battery-grade ferric phosphate and the lithium carbonate, and has the advantages of simple operation, short flow, low cost and contribution to mass production.
In order to achieve the technical object, the present invention provides a method for preparing battery grade iron phosphate and lithium carbonate by using crude lithium phosphate, the method comprising the following steps:
1) Grinding, dissolving and filtering the crude lithium phosphate in sequence to obtain a crude lithium phosphate solution;
2) Adjusting the pH value of the crude lithium phosphate solution to 0.1-3.0, extracting and separating Al by using an organic relatively crude lithium phosphate solution containing P204 with the conversion rate of 60-80 percent 3+ And Ca 2+ Obtaining raffinate;
3) Subjecting the raffinate to pH and P/Fe 2+ After the molar ratio is adjusted, oxidizing and precipitating phosphorus to obtain hydrated ferric phosphate and phosphorus-precipitated liquid, and drying the hydrated ferric phosphate to obtain battery-grade ferric phosphate;
4) Deep impurity removal is carried out on the phosphorus-precipitated liquid to obtain lithium-rich purifying liquid;
5) And precipitating lithium from the lithium-rich purification liquid through carbonate to obtain crude lithium carbonate, and purifying the crude lithium carbonate by a hydrogenation method to obtain the battery-grade lithium carbonate.
According to the technical scheme, through perfect combination of processes such as dissolution, extraction and impurity removal, ferric salt phosphorus precipitation, neutralization deep impurity removal, carbonate precipitation and the like, useful components such as phosphorus, lithium and the like in the crude lithium phosphate can be efficiently separated and recovered, the influence of impurities such as aluminum ions, calcium ions and the like on the purity of the product is avoided, high-value-added high-purity ferric phosphate and lithium carbonate products are obtained, and comprehensive utilization of the crude lithium phosphate is realized. More specifically, the key point of the technical scheme of the invention is that the selective separation of aluminum ions and calcium ions is realized by an extraction method in a phosphate solution system with high Li/Al (140-1330) and Li/Ca molar ratio and smaller Al and Ca concentration (below 0.5 g/L), when the Li/Al and Li/Ca molar ratio is higher, the extraction selectivity of the extractant P204 to the aluminum ions and the calcium ions is reduced, a large amount of lithium ions also enter an extraction organic phase, the concentration of the lithium ions in the lithium phosphate solution is reduced, meanwhile, the subsequent additional process is required to recover the lithium ions, and the conditions of water phase pH, extractant saponification rate and the like are cooperatively controlled, so that the high selective extraction of P204 to the aluminum ions and the calcium ions in the phosphate system can be realized, the concentrations of the aluminum ions and the calcium ions in the phosphate system are respectively reduced from 0.1-0.5 g/L and 0.2-0.5 g/L to below 10mg/L, the residual quantity of the aluminum ions and the calcium ions in the raffinate is low, the aluminum content in the final ferric phosphate product is lower than 5ppm, and the calcium content in the lithium carbonate product is lower than 50ppm; the concentration of lithium ions in the phosphate system is kept at 20-35 g/L, lithium is hardly lost, and the impurity removing effect is good and stable. According to the technical scheme, two key impurity metal ions of aluminum ions and calcium ions are removed, loss of lithium ions is avoided, subsequent obtaining of a battery-grade iron phosphate product and a lithium carbonate product with higher purity is facilitated, meanwhile, lithium recovery efficiency is improved, and a lithium recovery process is simplified.
As a preferable mode, the concentration of the crude lithium phosphate solution is 0.1-0.5 g/mL. The concentration of the crude lithium phosphate solution is more preferably 0.25 to 0.35g/mL. If the concentration of the crude lithium phosphate solution is higher, the removal of metal impurities is not facilitated, and if the concentration of the crude lithium phosphate solution is lower, the concentration of the finally obtained lithium ion solution is lower, and the precipitation recovery is not facilitated.
As a preferred embodiment, the crude lithium phosphate solution is adjusted to pH 1.2-2.7. P204 extractant pair Al at preferred pH 3+ And Ca 2+ With Li + Has larger extraction capacity difference and is more beneficial to Al 3+ And Ca 2+ Is extracted and separated. Further preferably, the pH is adjusted to 1.9 to 2.5.
As a preferred embodiment, the extraction method separates Al 3+ And Ca 2+ In the process, the volume concentration of P204 in the organic phase is 10-45%, the oil-water ratio is 1:9-8:1 (volume ratio), and the oil-water ratio is more preferably 1:1, a step of; the temperature is 10-40 ℃, and the extraction time is 2-40 min. The temperature is more preferably 30 to 40 ℃, and the extraction time is more preferably 5 to 15 minutes. The diluent in the organic phase is kerosene. The volume concentration of the extractant in the organic phase is more preferably 25 to 35%. Under the condition of strictly controlling the pH of the crude lithium phosphate solution, the preferred extraction conditions can be adopted to realize the process that Al 3+ And Ca 2+ The high-efficiency extraction and separation of the lithium ion battery can reduce the loss of lithium ions. As a preferred embodiment, the saponification rate of the extractant P204 is 60% -80. In the preferred saponificationThe extraction capacity of P204 to aluminum is stronger under the condition of the rate, and the extraction amount to lithium is low. The saponification rate of P204 is more preferably 70% to 80%, and if the saponification rate of P204 is too low, the saponification rate is further preferably 70% to 80%, the saponification rate is too low 3+ And Ca 2+ Is poor in the removal effect of P204, if the saponification rate of P204 is too high, the reaction is carried out against Li + Since the extraction capacity of P204 is enhanced, the lithium ions are entrained and lost, the extraction capacity of P204 for aluminum ions and calcium ions is stronger under the preferable saponification rate condition, and the extraction amount of the lithium ions is low.
As a preferred embodiment, the pH of the raffinate is adjusted to 0.2 to 1.5, P/Fe 2+ The molar ratio is adjusted to 0.95-1.2. The phosphorus/iron molar ratio is further preferably adjusted to 1.0 to 1.1. The pH is further preferably adjusted to 0.6 to 0.9. Adjusting P/Fe 2+ The iron source adopted by the molar ratio is a solution containing ferrous ions, such as ferrous sulfate solution, titanium white byproduct ferrous sulfate solution, an acid solution of elemental iron, ferrous chloride solution and ferrous nitrate solution. Further preferably, ferrous sulfate solution, sulfuric acid solution of elemental iron, ferrous sulfate such as titanium white byproduct ferrous sulfate.
As a preferable scheme, the oxidizing agent with 1 to 1.3 times of the theoretical amount is added in the oxidizing process, and the oxidizing agent comprises at least one of hydrogen peroxide, thiosulfate, peroxo salt, ozone, oxygen and air. The theoretical amount of oxidant is calculated as the stoichiometric amount (molar amount) of ferrous to ferric oxide ions. The addition amount of the oxidant is 1.05 to 1.2 times of the theoretical amount. Further preferred oxidizing agents are hydrogen peroxide, peroxo salts.
As a preferable scheme, the phosphorus precipitation process is carried out at the temperature of 80-110 ℃ for 2-21 h. The nucleation process of the ferric phosphate is cooperatively controlled by the initial pH value and the reaction temperature in the process of precipitating the phosphorus, so that Mn can be effectively avoided 2+ 、Mg 2+ The isodivalent metal ions enter the ferric phosphate crystal lattice, so that the ferric phosphate product can be controlled to have lower water content, and meanwhile, the generated hydrated ferric phosphate has high crystallinity, and lithium ions are prevented from being entrained due to the fact that the hydrated ferric phosphate contains more free water. The temperature is more preferably 90 to 100℃and the time is more preferably 6.0 to 10.0h。
As a preferable scheme, in the deep impurity removal process, the pH value of the solution after phosphorus precipitation is adjusted to 11-13, and the solution is reacted for 0.5-3.0 h at the temperature of 60-100 ℃. Deep purification and impurity removal of the solution after phosphorus precipitation can be realized by utilizing a hydrolysis mode 3+ 、Fe 3+ 、Mg 2+ 、Mn 2+ 、PO 4 3～ And the impurities are removed efficiently. The pH of the solution after phosphorus precipitation is further preferably adjusted to 11.5 to 12. The reaction time is more preferably 1.5 to 2.0 hours at a temperature of 85 to 95 ℃. The pH is adjusted by at least one of sodium hydroxide, ammonia water, potassium hydroxide, lithium hydroxide, sodium carbonate and sodium bicarbonate. Further preferred are strongly alkaline substances such as sodium hydroxide, potassium hydroxide and lithium hydroxide.
As a preferable scheme, in the process of precipitating lithium, carbonate with the theoretical amount of 1-2 times is added, and the reaction is carried out for 0.5-3 hours at the temperature of 80-100 ℃ to precipitate lithium. The theoretical amount of carbonate is measured as the molar amount of carbonate required to fully convert lithium ions to lithium carbonate. The carbonate amount is more preferably 1.1 to 1.5 times the theoretical amount. The reaction temperature is more preferably 90 to 100 ℃. The reaction time is more preferably 0.5 to 1.5 hours;
as a preferable scheme, in the hydrogenation purification process, the solid-to-liquid ratio is 1:22 to 40 percent of CO 2 The flow rate is 1-3L/min, and the decomposition temperature is 80-100 ℃. The solid-to-liquid ratio is further preferably 1: 22-30. CO 2 The flow rate is more preferably 1 to 2L/min. The decomposition temperature is more preferably 90 to 100 ℃.
The invention relates to a method for preparing battery grade ferric phosphate and lithium carbonate by using crude lithium phosphate, which comprises the following specific steps:
(1) Adding deionized water into 1g of crude lithium phosphate according to the liquid-solid ratio of (3-8) mL, then adjusting the pH value of the solution to 0.1-3.0, and filtering and separating to obtain crude lithium phosphate solution;
(2) Extracting and separating organic relatively crude lithium phosphate solution containing P204, saponifying the P204 by using 20% NaOH solution, wherein the saponification rate is 60% -80%, the volume concentration of the P204 in an organic phase is 10-45%, kerosene is a diluent, the ratio of oil to water is 1:9-8:1, the pH of an aqueous phase is adjusted to be 1.2-2.7, extracting is carried out for 2-40 min at 10-40 ℃, standing and phase separation are carried out to obtain raffinate, and the raffinate is the aluminum and calcium removing solution;
(3) Adding an iron source to raffinate according to the molar ratio of P/Fe of 0.95-1.2, regulating the pH value of the solution to 0.2-1.5, calculating the theoretical dosage of the oxidant according to the chemical dosage from ferrous oxide ion to iron ion, wherein the specific dosage is 1.0-1.3 times of the theoretical dosage, the reaction temperature is 80-110 ℃, the reaction time is 2-21 h, filtering and washing after the reaction is finished, and drying a filter cake to obtain battery grade ferric phosphate, wherein filtrate is phosphorus precipitation post-liquid;
(4) Adding a pH regulator into the solution after phosphorus precipitation to regulate the pH of the solution to 11-13, reacting at 60-100 ℃ for 0.5-3.0 h, and filtering to obtain filtrate, namely a lithium-rich solution;
(5) Adding carbonate with the theoretical dosage of 1.0-2.0 times to the lithium-rich solution, reacting for 0.5-3 hours at the temperature of 80-100 ℃ to precipitate lithium, filtering, wherein a filter cake is lithium carbonate, and after the filter cake is dried, performing solid-liquid mass ratio of 1:22 to 40 percent of CO 2 The flow rate is 1-3L/min, the primary lithium carbonate is purified at the decomposition temperature of 80-100 ℃, and the battery grade lithium carbonate is obtained after the purification.
Compared with the prior art, the technology provided by the invention has the beneficial effects that:
1. the method for preparing the battery-grade ferric phosphate and the lithium carbonate by using the crude lithium phosphate adopts an all-wet process, does not need roasting or autoclaving treatment of slag, has low energy consumption in the production process and does not cause the problems of waste gas emission and the like;
2. the method for preparing the battery grade ferric phosphate and the lithium carbonate by using the crude lithium phosphate can realize high Li by controlling the pH condition and the saponification rate of the P204 extractant + /Al 3+ And L + /Ca 2+ Al in crude lithium phosphate solution 3+ And Ca 2+ Extraction separation can not only realize the separation of impurity Al 3+ 、Ca 2+ And hardly extracts lithium in the solution;
3. the method for preparing the battery-grade ferric phosphate and the lithium carbonate by utilizing the crude lithium phosphate preferably recovers the phosphate radical in the crude lithium phosphate under the condition of high acid, so that not only can the effective separation of the phosphate radical and the lithium be realized, but also the high-value utilization of the phosphate radical can be realized, the loss of the lithium can not be caused, and an effective solution is provided for the utilization of the phosphorus.
4. According to the method for preparing the battery-grade ferric phosphate and the lithium carbonate by utilizing the crude lithium phosphate, disclosed by the invention, the phosphorus and the lithium in the crude lithium phosphate can be comprehensively and efficiently recovered, the battery-grade ferric phosphate and the lithium carbonate with high added values can be obtained at the same time, and the purpose of value-added utilization of the crude lithium phosphate can be achieved.
Drawings
Fig. 1 is a process flow diagram of preparing battery grade iron phosphate and lithium carbonate from crude lithium phosphate.
Detailed Description
The following specific examples are intended to further illustrate the present invention, but not to limit the scope of the claims.
TABLE 1 elemental composition of crude lithium phosphate
Example 1
Firstly, 100g of crude lithium phosphate is weighed, 450ml of pure water is added, 9mol/L of sulfuric acid is added until the solution is clear and transparent (pH=2.0), and the crude lithium phosphate solution is obtained by filtering, wherein Al in the solution 3+ The concentration is 0.3g/L, ca 2+ The concentration was 0.2g/L. Extracting lithium phosphate solution under the conditions of 30% of P204+70% of kerosene as extractant, 70% of P204 saponification rate, O/A=1:1, extraction temperature of 25 ℃ and extraction time of 15min, standing and layering after reaction, separating phases to obtain raffinate, and detecting to obtain raffinate Al 3+ The concentration is 0.03g/L, ca 2+ The concentration was 2mg/L. Adding FeSO 4 ·7H 2 O is added in raffinate, the ratio of ferrous ions to phosphate radicals is 1.1:1, 9mol/L sulfuric acid is added to adjust the pH value of the mixed solution to 0.7, hydrogen peroxide solution with the dosage of 1.2 times that required by ferrous ions is slowly added dropwise, after the ferrous ions are completely oxidized into iron ions, the iron ions are transferred into an oil bath pot to react for 7 hours at the constant temperature of 95 ℃, after the reaction is finished, vacuum suction filtration is carried out, filtrate is phosphorus-precipitating liquid, and filter cake is obtained after washing and dryingHydrated iron phosphate product having tap density of 0.69g/cm -3 The yield of phosphorus is 98.82%, and the lithium loss is less than 0.2%. And (5) returning washing water to the complex acid to dissolve the crude lithium phosphate for use.
And adding NaOH solid into the solution after phosphorus precipitation to adjust the pH to 11.5, reacting for 2 hours, and filtering to obtain a filtrate which is a lithium-rich solution. Adding Na which is 1.2 times of the dosage required by lithium precipitation 2 CO 3 Carrying out solid-liquid separation on the solid at the constant temperature of 95 ℃ for 1h, and drying the solid according to the solid-liquid ratio of 1: 22. CO 2 The flow rate is 1L/min, the decomposition temperature is 90 ℃ for hydrogenation purification, and the purified solid is washed with water and dried to obtain the battery grade lithium carbonate. The mother liquor of the hydrogenation process is used for dissolving lithium carbonate in the next hydrogenation process.
Example 2
Firstly, 100g of crude lithium phosphate is weighed, 350ml of pure water is added, 9mol/L of sulfuric acid is added until the solution is clear and transparent (pH=2.2), and the crude lithium phosphate solution is obtained by filtering, wherein Al in the solution 3+ The concentration is 0.3g/L, ca 2+ The concentration was 0.3g/L. Then, extracting the crude lithium phosphate solution under the conditions that the volume concentration is 35% of P204+65% of kerosene is used as an extractant, the saponification rate of P204 is 75%, the O/A=1:1, the extraction temperature is 25 ℃ and the extraction time is 15min, standing and layering, and then separating phases to obtain raffinate, and detecting to obtain raffinate Al 3+ The concentration is 0.04g/L, ca 2+ The concentration is 5mg/L. Adding a titanium white byproduct ferrous sulfate solution to raffinate, wherein the ratio of ferrous ions to phosphate radicals is 1.01:1, adding sulfuric acid with the concentration of 9mol/L to adjust the pH value of the mixed solution to 0.8, slowly dropwise adding a sodium thiosulfate solution with the theoretical quantity of 1.2 times that of the ferrous ions, after the ferrous ions are completely oxidized into iron ions, transferring the iron ions into an oil bath kettle, reacting for 7 hours at the constant temperature of 95 ℃, after the reaction is finished, carrying out vacuum suction filtration, wherein the filtrate is a phosphorus-precipitating solution, washing and drying a filter cake to obtain a hydrated ferric phosphate product, and the tap density is 0.71g/cm -3 The yield of phosphorus is 99.01%, and the lithium loss is less than 0.2%. And (5) returning washing water to the complex acid to dissolve the crude lithium phosphate for use.
And adding NaOH solid into the solution after phosphorus precipitation to adjust the pH to 12, reacting for 2 hours, and filtering to obtain a filtrate which is a lithium-rich solution. Adding 1.2 times of Na 2 CO 3 Carrying out solid-liquid separation on the solid at the constant temperature of 95 ℃ for 1h, and drying the solid according to the solid-liquid ratio of 1: 22. CO 2 The flow rate is 1L/minAnd (3) carrying out hydrogenation purification at the decomposition temperature of 95 ℃, and washing and drying the purified solid to obtain the battery-grade lithium carbonate. The mother liquor of the hydrogenation process is used for dissolving lithium carbonate in the next hydrogenation process.
Example 3
Firstly, 100g of crude lithium phosphate is weighed, 350ml of pure water is added, 9mol/L of sulfuric acid is added until the solution is clear and transparent (pH=2.0), and the crude lithium phosphate solution is obtained by filtering, wherein Al in the solution 3+ The concentration is 0.3g/L, ca 2+ The concentration was 0.3g/L. Then, taking kerosene with the volume concentration of 40% P204+60% as an extractant, the saponification rate of P204 being 80%, O/A=1:1, the extraction temperature being 35 ℃ and the extraction time being 20min for carrying out extraction reaction, standing and layering after the reaction, and separating phases to obtain raffinate, wherein Al in the raffinate 3+ The concentration is 0.02g/L, ca 2+ The concentration was 8mg/L. Adding sulfuric acid solution of simple substance iron into raffinate, wherein the ratio of ferrous ions to phosphate radicals is 1.1:1, adding sulfuric acid of 9mol/L to regulate the pH value of the mixed solution to 0.8, slowly dropwise adding sodium peroxodisulfate solution of which the dosage is 1.2 times that of the ferrous ions, completely oxidizing the ferrous ions into iron ions, transferring the iron ions into an oil bath pot of 100 ℃ for constant-temperature reaction for 7 hours, after the reaction is finished, carrying out vacuum suction filtration, obtaining a filtrate after phosphorus precipitation, washing and drying a filter cake to obtain a hydrated ferric phosphate product, wherein the tap density is 0.71g/cm -3 The yield of phosphorus is 98.54%, and the lithium loss is less than 0.2%. And (5) returning washing water to the complex acid to dissolve the crude lithium phosphate for use.
And adding NaOH solid into the solution after phosphorus precipitation to adjust the pH to 12, reacting for 2 hours, and filtering to obtain a filtrate which is a lithium-rich solution. Adding Na 1.3 times of theoretical amount required by lithium precipitation 2 CO 3 Solid is reacted for 1h at the constant temperature of 100 ℃ to carry out solid-liquid separation, and the solid is dried and then mixed with CO according to the solid-liquid ratio of 1:25 2 The flow rate is 1.5L/min, the decomposition temperature is 95 ℃ for hydrogenation purification, and the purified solid is washed with water and dried to obtain the battery grade lithium carbonate. The mother liquor of the hydrogenation process is used for dissolving lithium carbonate in the next hydrogenation process.
Comparative example 1
The phosphorus removal temperature is 70 ℃, the rest conditions and the rest processes are the same as those of the case 1, and the experimental results are as follows: the yield of the hydrated ferric phosphate product is only 70.3%, the lithium loss is 0.1%, and the tap density is only 0.45g/cm 3 Far lower than the national standard of 0.6g/cm 3 . Because ofThe activation energy of the ferric phosphate reaction is high, the reaction rate is greatly influenced by the temperature, and the reaction rate is low when the temperature is low, so the reaction is incomplete.
Comparative example 2
Except for iron phosphate, the initial pH value is 2.5, the rest conditions and the rest processes are the same as those of case 2, and the experimental result is that: the solution becomes paste during the reaction, the Al content in the ferric phosphate product is up to 0.04%, exceeds the national standard upper limit by 0.03%, the water content of the ferric phosphate reaches 60%, the ferric phosphate is difficult to filter, the filtrate is basically absent, and the next lithium extraction cannot be performed. The pH is a key factor affecting the preparation of iron phosphate, the lower the acidity in the solution, the faster the reaction rate of iron phosphate, and Al 3+ And Fe (Fe) 3+ Is similar in nature and is also susceptible to reaction with phosphate to form a precipitate. When the pH environment in the solution is 2.5, the generation speed of the ferric phosphate is extremely high, and the generated precipitate wraps impurities, and Al 3+ At this time, precipitation is also rapidly generated, and the impurity content of the iron phosphate product is too high to be qualified. The reaction speed of the ferric phosphate is high, and the generated ferric phosphate has small particles and strong water absorption, so that the ferric phosphate has high water content and the solution is difficult to filter.
Comparative example 3
Except that Al and Ca are not extracted before the preparation of the ferric phosphate, the rest conditions and the rest processes are the same as those of case 3, and the experimental results are as follows: the Al content in the product hydrated ferric phosphate is 0.07%, exceeds the national standard upper limit, and the recovery yield of phosphorus is 98.62%. The calcium content in the lithium carbonate product is 0.15 percent, which does not meet the standard of battery grade lithium carbonate. Because calcium hydroxide is slightly soluble in water, ca cannot be deeply removed by simply regulating and controlling pH 2+ And Ca 2+ With Li + The solubility of calcium carbonate in water is extremely low in preference to Li and carbonate reactions, and therefore, even a trace amount of calcium ions in solution will react with carbonate in solution to reduce the purity of the lithium carbonate product.
Comparative example 4
The conditions and procedures were the same as in case 1 except that the saponification rate of the extractant was 100%, and the experimental results were: although Al is contained in the extract 3+ The concentration was reduced to 2mg// L, but the solution was severely emulsified and phase separation was difficult. 30% of the lithium is extracted and lithium is lost severelyThe weight is more than 30 percent, and the lithium concentration in the solution is reduced from 30g/L to 18g/L. Because P204 is H after saponification + Is covered by Na + Substituted, but the impurity ion content in the solution is low, when the impurity ion is extracted, the saponified P204 still has a considerable extraction capacity, and Li + The binding capacity with P204 is stronger than that of Na + In addition, the concentration of Li in the solution is high and is more than 30g/L, so that the saponified P204 continues to be matched with Li + The extraction reaction is carried out, so that part of Li in the solution is extracted, the concentration of Li in the solution is greatly reduced, and the subsequent lithium precipitation reaction is adversely affected.
Comparative example 5
Except that the saponification rate of the extractant is 50%, the conditions and the processes are the same as those of the case 1, and the experimental results are as follows: the Al concentration in the raffinate was 0.2g/L, only 33% of Al was extracted, the raffinate was used to prepare iron phosphate according to the conditions of case 1, the Al content in the product was 0.07%, and the impurity Al content in the product was unacceptable.
Comparative example 6
The rest conditions and the process are the same as those of the first case except that the pH value of the solution after phosphorus precipitation is adjusted to 9.0, and the experimental result is as follows: the content of magnesium in the purified lithium carbonate impurity is more than 0.05 percent, and the requirement of battery grade lithium carbonate is not met. Due to Mg 2+ With Li + The solubility of magnesium carbonate in water is extremely low in preference to Li and carbonate reactions, and therefore, even a trace amount of magnesium ions in solution will react with carbonate in solution to reduce the purity of the lithium carbonate product.
TABLE 2 analysis of hydrated iron phosphate composition
Table 3: lithium carbonate component content for battery
As can be seen from Table 2, the lithium carbonate prepared by the method meets the standard, has lower impurity content and higher purity, and the purity of the obtained lithium carbonate product is more than 99.5 percent, and the lithium carbonate prepared by the method can be directly used as lithium carbonate for batteries.
Claims (10)
1. A method for preparing battery grade ferric phosphate and lithium carbonate by using crude lithium phosphate, which is characterized in that: the method comprises the following steps:
1) Grinding, dissolving and filtering the crude lithium phosphate in sequence to obtain a crude lithium phosphate solution;
2) Adjusting the pH value of the crude lithium phosphate solution to 0.1-3.0, extracting and separating Al by using an organic relatively crude lithium phosphate solution containing P204 with a saponification rate of 60-80% 3+ And Ca 2+ Obtaining raffinate;
3) Subjecting the raffinate to pH and P/Fe 2+ After the molar ratio is adjusted, oxidizing and precipitating phosphorus to obtain hydrated ferric phosphate and phosphorus-precipitated liquid, and drying the hydrated ferric phosphate to obtain battery-grade ferric phosphate;
4) Deep impurity removal is carried out on the phosphorus-precipitated liquid to obtain lithium-rich purifying liquid;
5) And precipitating lithium from the lithium-rich purification liquid through carbonate to obtain crude lithium carbonate, and purifying the crude lithium carbonate by a hydrogenation method to obtain the battery-grade lithium carbonate.
2. The method for preparing battery grade iron phosphate and lithium carbonate from crude lithium phosphate according to claim 1, wherein: the concentration of the crude lithium phosphate solution is 0.1-0.5 g/mL.
3. The method for preparing battery grade iron phosphate and lithium carbonate from crude lithium phosphate according to claim 1, wherein: the pH of the crude lithium phosphate solution is adjusted to 1.2-2.7.
4. A method for preparing battery grade ferric phosphate and lithium carbonate by using crude lithium phosphate according to claim 1, 2 or 3, which is characterized in thatThe method is characterized in that: the extraction separates Al 3+ And Ca 2+ In the process, the volume concentration of P204 in the organic phase is 10-45%, the oil-water ratio is 1:9-8:1, the temperature is 10-40 ℃, and the extraction time is 2-40 min.
5. The method for preparing battery grade iron phosphate and lithium carbonate from crude lithium phosphate according to claim 1, wherein: the pH of the raffinate is regulated to be 0.2-1.5, and the P/Fe ratio is regulated to be 0.2-1.5 2+ The molar ratio is adjusted to 0.95-1.2.
6. The method for preparing battery grade iron phosphate and lithium carbonate from crude lithium phosphate according to claim 1, wherein: in the oxidation process, an oxidant with the theoretical amount of 1-1.3 times is added, wherein the oxidant comprises at least one of hydrogen peroxide, thiosulfate, peroxo acid salt, ozone, oxygen and air.
7. The method for preparing battery grade iron phosphate and lithium carbonate from crude lithium phosphate according to claim 1, wherein: in the process of precipitating phosphorus, the reaction is carried out for 2 to 21 hours at the temperature of 80 to 110 ℃.
8. The method for preparing battery grade iron phosphate and lithium carbonate from crude lithium phosphate according to claim 1, wherein: in the process of deep impurity removal, the pH value of the solution after phosphorus precipitation is adjusted to 11-13, and the solution reacts for 0.5-3.0 h at the temperature of 60-100 ℃.
9. The method for preparing battery grade iron phosphate and lithium carbonate from crude lithium phosphate according to claim 1, wherein: in the process of precipitating lithium, adding carbonate with the theoretical amount of 1-2 times, and reacting for 0.5-3 h at the temperature of 80-100 ℃.
10. The method for preparing battery grade iron phosphate and lithium carbonate from crude lithium phosphate according to claim 1, wherein: in the hydrogenation purification process, the solid-liquid mass ratio is 1:22～40，CO 2 The flow rate is 1-3L/min, and the decomposition temperature is 80-100 ℃.
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Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104745823A (en) * | 2015-03-12 | 2015-07-01 | 湖南邦普循环科技有限公司 | Method for recycling lithium from waste lithium ion battery |
| CN106784824A (en) * | 2017-02-24 | 2017-05-31 | 赣南师范大学 | A kind of method that lithium iron manganese phosphate anode material prepares lithium carbonate |
| CN107720716A (en) * | 2017-11-21 | 2018-02-23 | 成都开飞高能化学工业有限公司 | The technique for preparing battery-level lithium carbonate and ferric phosphate from crude product lithium phosphate recovery lithium phosphorus |
| CN108821255A (en) * | 2018-07-11 | 2018-11-16 | 方嘉城 | A kind of preparation method of ferric phosphate |
| CN109167118A (en) * | 2018-07-26 | 2019-01-08 | 中国科学院过程工程研究所 | The method of comprehensive utilization of ferric phosphate lithium cell electrode material |
| US20190161357A1 (en) * | 2016-08-26 | 2019-05-30 | Hunan Jinyuan New Materials Co., Ltd. | Method for preparing lithium carbonate from lithium iron phosphate battery scraps and lithium carbonate thereof |
| CN110013822A (en) * | 2018-01-07 | 2019-07-16 | 中南大学 | A kind of method of waste and old lithium ion battery recycling co-production lithium adsorbent |
| CN111924817A (en) * | 2020-07-24 | 2020-11-13 | 中南大学 | Method for comprehensively utilizing waste lithium iron phosphate anode material |
| CN113800494A (en) * | 2021-09-14 | 2021-12-17 | 广东中金岭南环保工程有限公司 | Method for selectively recovering aluminum from acid leaching solution of waste lithium iron phosphate battery material |
| CN113802017A (en) * | 2021-09-14 | 2021-12-17 | 湖南中金岭南康盟环保科技有限公司 | Method for separating and recovering aluminum in acid leachate of waste lithium iron phosphate battery positive electrode material by extraction method |
| WO2022228233A1 (en) * | 2021-04-25 | 2022-11-03 | 湖南金源新材料股份有限公司 | Method for extracting and preparing battery-grade lithium carbonate from p507 raffinate, and extraction device |
| US20230038978A1 (en) * | 2021-08-02 | 2023-02-09 | Ascend Elements, Inc. | Lithium Iron Phosphate (LFP) battery recycling |
| US20230050044A1 (en) * | 2020-11-23 | 2023-02-16 | Hunan Jin Yuan New Materials Joint Stock Company Limited | Comprehensive recycling method for waste lithium iron phosphate battery |
-
2023
- 2023-04-20 CN CN202310428116.4A patent/CN116409769A/en active Pending
Patent Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104745823A (en) * | 2015-03-12 | 2015-07-01 | 湖南邦普循环科技有限公司 | Method for recycling lithium from waste lithium ion battery |
| US20190161357A1 (en) * | 2016-08-26 | 2019-05-30 | Hunan Jinyuan New Materials Co., Ltd. | Method for preparing lithium carbonate from lithium iron phosphate battery scraps and lithium carbonate thereof |
| CN106784824A (en) * | 2017-02-24 | 2017-05-31 | 赣南师范大学 | A kind of method that lithium iron manganese phosphate anode material prepares lithium carbonate |
| CN107720716A (en) * | 2017-11-21 | 2018-02-23 | 成都开飞高能化学工业有限公司 | The technique for preparing battery-level lithium carbonate and ferric phosphate from crude product lithium phosphate recovery lithium phosphorus |
| CN110013822A (en) * | 2018-01-07 | 2019-07-16 | 中南大学 | A kind of method of waste and old lithium ion battery recycling co-production lithium adsorbent |
| CN108821255A (en) * | 2018-07-11 | 2018-11-16 | 方嘉城 | A kind of preparation method of ferric phosphate |
| CN109167118A (en) * | 2018-07-26 | 2019-01-08 | 中国科学院过程工程研究所 | The method of comprehensive utilization of ferric phosphate lithium cell electrode material |
| CN111924817A (en) * | 2020-07-24 | 2020-11-13 | 中南大学 | Method for comprehensively utilizing waste lithium iron phosphate anode material |
| US20230050044A1 (en) * | 2020-11-23 | 2023-02-16 | Hunan Jin Yuan New Materials Joint Stock Company Limited | Comprehensive recycling method for waste lithium iron phosphate battery |
| WO2022228233A1 (en) * | 2021-04-25 | 2022-11-03 | 湖南金源新材料股份有限公司 | Method for extracting and preparing battery-grade lithium carbonate from p507 raffinate, and extraction device |
| US20230038978A1 (en) * | 2021-08-02 | 2023-02-09 | Ascend Elements, Inc. | Lithium Iron Phosphate (LFP) battery recycling |
| CN113800494A (en) * | 2021-09-14 | 2021-12-17 | 广东中金岭南环保工程有限公司 | Method for selectively recovering aluminum from acid leaching solution of waste lithium iron phosphate battery material |
| CN113802017A (en) * | 2021-09-14 | 2021-12-17 | 湖南中金岭南康盟环保科技有限公司 | Method for separating and recovering aluminum in acid leachate of waste lithium iron phosphate battery positive electrode material by extraction method |
Non-Patent Citations (1)
| Title |
|---|
| 周有池;文小强;郭春平;刘雯雯;: "铁锂废料制备电池级碳酸锂和磷酸铁工艺研究", 有色金属(冶炼部分), no. 04, 12 April 2019 (2019-04-12), pages 78 - 82 * |
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