CN116835614A - Method for preparing lithium carbonate by using lithium-containing waste residues and application thereof - Google Patents
Method for preparing lithium carbonate by using lithium-containing waste residues and application thereof Download PDFInfo
- Publication number
- CN116835614A CN116835614A CN202310791764.6A CN202310791764A CN116835614A CN 116835614 A CN116835614 A CN 116835614A CN 202310791764 A CN202310791764 A CN 202310791764A CN 116835614 A CN116835614 A CN 116835614A
- Authority
- CN
- China
- Prior art keywords
- lithium
- containing waste
- carbonate
- leaching
- liquid
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 title claims abstract description 188
- 229910052744 lithium Inorganic materials 0.000 title claims abstract description 188
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 title claims abstract description 102
- 229910052808 lithium carbonate Inorganic materials 0.000 title claims abstract description 102
- 239000002699 waste material Substances 0.000 title claims abstract description 101
- 238000000034 method Methods 0.000 title claims abstract description 82
- 239000012535 impurity Substances 0.000 claims abstract description 98
- 238000002386 leaching Methods 0.000 claims abstract description 94
- 239000007788 liquid Substances 0.000 claims abstract description 90
- 238000006243 chemical reaction Methods 0.000 claims abstract description 43
- JLVVSXFLKOJNIY-UHFFFAOYSA-N Magnesium ion Chemical compound [Mg+2] JLVVSXFLKOJNIY-UHFFFAOYSA-N 0.000 claims abstract description 41
- 229910001425 magnesium ion Inorganic materials 0.000 claims abstract description 41
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 claims abstract description 40
- BHPQYMZQTOCNFJ-UHFFFAOYSA-N Calcium cation Chemical compound [Ca+2] BHPQYMZQTOCNFJ-UHFFFAOYSA-N 0.000 claims abstract description 39
- 229910001424 calcium ion Inorganic materials 0.000 claims abstract description 37
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 37
- 238000001556 precipitation Methods 0.000 claims abstract description 37
- 229910001416 lithium ion Inorganic materials 0.000 claims abstract description 31
- 238000000926 separation method Methods 0.000 claims abstract description 31
- 229910052742 iron Inorganic materials 0.000 claims abstract description 26
- 239000003456 ion exchange resin Substances 0.000 claims abstract description 23
- 229920003303 ion-exchange polymer Polymers 0.000 claims abstract description 23
- NWUYHJFMYQTDRP-UHFFFAOYSA-N 1,2-bis(ethenyl)benzene;1-ethenyl-2-ethylbenzene;styrene Chemical compound C=CC1=CC=CC=C1.CCC1=CC=CC=C1C=C.C=CC1=CC=CC=C1C=C NWUYHJFMYQTDRP-UHFFFAOYSA-N 0.000 claims abstract description 22
- -1 iron ions Chemical class 0.000 claims abstract description 20
- ACMQFLCUSWMWKH-UHFFFAOYSA-N 2-oxoheptylphosphonic acid Chemical compound CCCCCC(=O)CP(O)(O)=O ACMQFLCUSWMWKH-UHFFFAOYSA-N 0.000 claims abstract description 19
- 239000002253 acid Substances 0.000 claims abstract description 18
- 238000004519 manufacturing process Methods 0.000 claims abstract description 17
- 239000007800 oxidant agent Substances 0.000 claims abstract description 15
- 230000001590 oxidative effect Effects 0.000 claims abstract description 13
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 claims abstract description 11
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 11
- 238000002156 mixing Methods 0.000 claims abstract description 11
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims description 22
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 18
- QAOWNCQODCNURD-UHFFFAOYSA-N sulfuric acid Substances OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 17
- 229910021529 ammonia Inorganic materials 0.000 claims description 7
- 239000003513 alkali Substances 0.000 claims description 4
- 238000004064 recycling Methods 0.000 abstract description 7
- 238000003912 environmental pollution Methods 0.000 abstract description 6
- 239000000243 solution Substances 0.000 description 78
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 48
- 239000011777 magnesium Substances 0.000 description 25
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 24
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 24
- 239000011575 calcium Substances 0.000 description 24
- 239000011347 resin Substances 0.000 description 21
- 229920005989 resin Polymers 0.000 description 21
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 20
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 20
- 229910052749 magnesium Inorganic materials 0.000 description 20
- 230000000052 comparative effect Effects 0.000 description 19
- 239000012452 mother liquor Substances 0.000 description 19
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 18
- 239000011574 phosphorus Substances 0.000 description 18
- 229910052698 phosphorus Inorganic materials 0.000 description 18
- 229910052791 calcium Inorganic materials 0.000 description 17
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 description 17
- 239000010413 mother solution Substances 0.000 description 16
- 239000012528 membrane Substances 0.000 description 13
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 12
- 235000011114 ammonium hydroxide Nutrition 0.000 description 12
- 229910000029 sodium carbonate Inorganic materials 0.000 description 12
- ATRRKUHOCOJYRX-UHFFFAOYSA-N Ammonium bicarbonate Chemical compound [NH4+].OC([O-])=O ATRRKUHOCOJYRX-UHFFFAOYSA-N 0.000 description 11
- 239000001099 ammonium carbonate Substances 0.000 description 11
- 238000003756 stirring Methods 0.000 description 11
- 239000000203 mixture Substances 0.000 description 10
- 238000005406 washing Methods 0.000 description 8
- 238000001704 evaporation Methods 0.000 description 7
- 230000001105 regulatory effect Effects 0.000 description 7
- 239000000126 substance Substances 0.000 description 7
- 235000012501 ammonium carbonate Nutrition 0.000 description 6
- 239000003153 chemical reaction reagent Substances 0.000 description 6
- 238000010612 desalination reaction Methods 0.000 description 6
- 238000001035 drying Methods 0.000 description 6
- 230000008020 evaporation Effects 0.000 description 6
- 239000002244 precipitate Substances 0.000 description 6
- 239000013535 sea water Substances 0.000 description 6
- 239000002893 slag Substances 0.000 description 6
- 229910000013 Ammonium bicarbonate Inorganic materials 0.000 description 5
- 230000032683 aging Effects 0.000 description 5
- 235000012538 ammonium bicarbonate Nutrition 0.000 description 5
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 4
- 239000000706 filtrate Substances 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- 238000011084 recovery Methods 0.000 description 4
- 239000002351 wastewater Substances 0.000 description 4
- 239000005955 Ferric phosphate Substances 0.000 description 3
- WMFOQBRAJBCJND-UHFFFAOYSA-M Lithium hydroxide Chemical compound [Li+].[OH-] WMFOQBRAJBCJND-UHFFFAOYSA-M 0.000 description 3
- 229910019142 PO4 Inorganic materials 0.000 description 3
- 238000004090 dissolution Methods 0.000 description 3
- 229940032958 ferric phosphate Drugs 0.000 description 3
- 239000003337 fertilizer Substances 0.000 description 3
- 238000001914 filtration Methods 0.000 description 3
- 238000005189 flocculation Methods 0.000 description 3
- 230000016615 flocculation Effects 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- WBJZTOZJJYAKHQ-UHFFFAOYSA-K iron(3+) phosphate Chemical compound [Fe+3].[O-]P([O-])([O-])=O WBJZTOZJJYAKHQ-UHFFFAOYSA-K 0.000 description 3
- 229910000399 iron(III) phosphate Inorganic materials 0.000 description 3
- INHCSSUBVCNVSK-UHFFFAOYSA-L lithium sulfate Inorganic materials [Li+].[Li+].[O-]S([O-])(=O)=O INHCSSUBVCNVSK-UHFFFAOYSA-L 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 239000010452 phosphate Substances 0.000 description 3
- 239000002994 raw material Substances 0.000 description 3
- RBTVSNLYYIMMKS-UHFFFAOYSA-N tert-butyl 3-aminoazetidine-1-carboxylate;hydrochloride Chemical compound Cl.CC(C)(C)OC(=O)N1CC(N)C1 RBTVSNLYYIMMKS-UHFFFAOYSA-N 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 2
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonium chloride Substances [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 description 2
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 2
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 2
- 239000010405 anode material Substances 0.000 description 2
- OSGAYBCDTDRGGQ-UHFFFAOYSA-L calcium sulfate Chemical compound [Ca+2].[O-]S([O-])(=O)=O OSGAYBCDTDRGGQ-UHFFFAOYSA-L 0.000 description 2
- 230000001276 controlling effect Effects 0.000 description 2
- 238000005265 energy consumption Methods 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 229910001386 lithium phosphate Inorganic materials 0.000 description 2
- BWHMMNNQKKPAPP-UHFFFAOYSA-L potassium carbonate Chemical compound [K+].[K+].[O-]C([O-])=O BWHMMNNQKKPAPP-UHFFFAOYSA-L 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 230000001698 pyrogenic effect Effects 0.000 description 2
- 239000010865 sewage Substances 0.000 description 2
- TWQULNDIKKJZPH-UHFFFAOYSA-K trilithium;phosphate Chemical compound [Li+].[Li+].[Li+].[O-]P([O-])([O-])=O TWQULNDIKKJZPH-UHFFFAOYSA-K 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229910019440 Mg(OH) Inorganic materials 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- WFGBXPXOFAFPTO-UHFFFAOYSA-N [P].[Fe].[Li] Chemical compound [P].[Fe].[Li] WFGBXPXOFAFPTO-UHFFFAOYSA-N 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- MXZRMHIULZDAKC-UHFFFAOYSA-L ammonium magnesium phosphate Chemical compound [NH4+].[Mg+2].[O-]P([O-])([O-])=O MXZRMHIULZDAKC-UHFFFAOYSA-L 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910000019 calcium carbonate Inorganic materials 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000013522 chelant Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 229960004887 ferric hydroxide Drugs 0.000 description 1
- 239000008394 flocculating agent Substances 0.000 description 1
- GPRLSGONYQIRFK-UHFFFAOYSA-N hydron Chemical class [H+] GPRLSGONYQIRFK-UHFFFAOYSA-N 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- RUTXIHLAWFEWGM-UHFFFAOYSA-H iron(3+) sulfate Chemical compound [Fe+3].[Fe+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O RUTXIHLAWFEWGM-UHFFFAOYSA-H 0.000 description 1
- IEECXTSVVFWGSE-UHFFFAOYSA-M iron(3+);oxygen(2-);hydroxide Chemical compound [OH-].[O-2].[Fe+3] IEECXTSVVFWGSE-UHFFFAOYSA-M 0.000 description 1
- 229910000360 iron(III) sulfate Inorganic materials 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 239000012071 phase Substances 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 1
- 239000007774 positive electrode material Substances 0.000 description 1
- 229910000027 potassium carbonate Inorganic materials 0.000 description 1
- 230000001376 precipitating effect Effects 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 238000001223 reverse osmosis Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000007790 solid phase Substances 0.000 description 1
- 239000002910 solid waste Substances 0.000 description 1
- 229910052567 struvite Inorganic materials 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 239000002912 waste gas Substances 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
-
- 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
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Processing Of Solid Wastes (AREA)
Abstract
The invention relates to the technical field of recycling of lithium-containing waste resources, in particular to a method for preparing lithium carbonate by utilizing lithium-containing waste residues and application thereof. The method for preparing lithium carbonate by using the lithium-containing waste residues comprises the following steps: mixing lithium-containing waste residues, acid and an oxidant, leaching, and carrying out solid-liquid separation to obtain a lithium-containing leaching solution, wherein the leaching rate of lithium ions in the leaching solution is more than 95%, and the leaching rate of iron ions is less than 0.05%; mixing the leaching solution with impurity removing agent to remove calcium ion, magnesium ion and HPO 4 2‑ Impurities, and carrying out solid-liquid separation to obtain lithium-containing impurity-removing liquid; removing residual calcium ion and magnesium ion impurities from the impurity removing liquid through ion exchange resin to obtain lithium-rich liquid; and carrying out solid-liquid separation to obtain lithium carbonate after lithium precipitation reaction between the lithium-rich liquid and carbonate. The method has the advantages of simple process flow, low production cost, high lithium yield, high resource utilization rate, high added value and little environmental pollution, and can realize the high-efficiency recycling of lithium-containing waste residuesAnd the like.
Description
Technical Field
The invention relates to the technical field of recycling of lithium-containing waste resources, in particular to a method for preparing lithium carbonate by utilizing lithium-containing waste residues and application thereof.
Background
In recent years, the new energy industry has rapidly developed, and lithium iron phosphate batteries have most rapidly developed due to the outstanding safety. In the production process of lithium iron phosphate, a large amount of wastewater containing lithium and phosphorus is generated, the wastewater has the characteristics of high COD, high phosphorus and the like, and usually iron-based and calcium-based flocculants are added for flocculation precipitation, and the treated wastewater is discharged after reaching the standard. The lithium-containing waste residue generated after sewage treatment is used as solid waste, so that the waste disposal cost can be increased, and the loss of lithium and phosphorus resources can be caused.
In general, the recovery of lithium iron phosphate materials adopts two paths of a pyrogenic process and a wet process, for example, patent CN112111651 discloses a pyrogenic recovery process of waste lithium ion battery powder, and the powder, a carbon-containing material and a hydrogen ion salt are uniformly mixed and roasted, and the roasting is carried out in two stages; dissolving the roasted product in alkaline solution with pH of 10-11, introducing CO 2 Filtering and washing until the pH value is 8-9 to obtain filtrate and filter residue; and heating and evaporating the filtrate to obtain lithium carbonate. As further patent CN108899601 discloses a method for recovering lithium and iron from lithium iron phosphate, dissolving scrapped lithium iron phosphate slag with sulfuric acid and ferric sulfate, leaching out iron, lithium and phosphorus, then adding oxidant, reacting iron and phosphate to produce ferric phosphate precipitate and a small amount of ferric hydroxide, converting lithium into lithium sulfate solution dissolved in water, filtering to obtain lithium sulfate solution, and adding sodium carbonate into the lithium sulfate solution to prepare lithium carbonate product.
However, the waste slag containing lithium and phosphorus generated in the production process of the lithium iron phosphate contains a large amount of calcium, magnesium, phosphorus and iron impurities after flocculation precipitation, the lithium content is low, the cost for extracting lithium by using a fire method is extremely high, and the roasting waste gas is excessive, so that the environmental protection requirement is difficult to reach; the wet method is used for extracting lithium, so that the amount of the concentrated acid is extremely large, the impurities are more, and the components of the leaching solution are complex; the chemical method has the advantages of high consumption of impurity removing reagents, complicated steps and low lithium yield.
Therefore, the preparation process of the battery-grade lithium carbonate is environment-friendly, realizes the resource utilization of lithium-containing waste residues, and has important significance.
In view of this, the present invention has been made.
Disclosure of Invention
The first aim of the invention is to provide a method for preparing lithium carbonate by using lithium-containing waste residues, which aims to solve the problems of poor recovery effect and high cost of the existing lithium iron phosphate materials.
The second object of the invention is to provide an application of lithium carbonate prepared by the method for preparing lithium carbonate by using lithium-containing waste residues in a lithium ion battery.
In order to achieve the above object of the present invention, the following technical solutions are specifically adopted:
the invention provides a method for preparing lithium carbonate by utilizing lithium-containing waste residues, which comprises the following steps:
mixing lithium-containing waste residues, acid and an oxidant, and performing leaching treatment, and performing solid-liquid separation to obtain a lithium-containing leaching solution, wherein the leaching rate of lithium ions in the leaching solution is more than 95%, and the leaching rate of iron ions is less than 0.05%;
mixing the leaching solution with impurity removing agent to remove calcium ion, magnesium ion and HPO 4 2- Impurities, and carrying out solid-liquid separation to obtain lithium-containing impurity-removing liquid;
removing residual calcium ion and magnesium ion impurities from the impurity removing liquid through ion exchange resin to obtain lithium-rich liquid;
and carrying out solid-liquid separation to obtain lithium carbonate after lithium precipitation reaction between the lithium-rich liquid and carbonate.
The invention solves the problems of environmental pollution and resource waste caused by waste residues generated in the battery production process. The method has the advantages of simple process flow, high lithium yield, high resource utilization rate, high added value, low production cost, small environmental pollution and the like.
The invention also provides application of the lithium carbonate prepared by the method for preparing lithium carbonate by using the lithium-containing waste residue in a lithium ion battery.
The battery grade lithium carbonate prepared by the method for preparing lithium carbonate by using the lithium-containing waste residues can be used as a raw material for preparing the anode material of the lithium ion battery, so that not only can the resource waste be avoided, but also the production cost of the lithium ion battery is reduced.
Compared with the prior art, the invention has the beneficial effects that:
(1) The method for preparing lithium carbonate by using the lithium-containing waste residue provided by the invention realizes the efficient recycling of the lithium-containing waste residue, and has the advantages of low production cost, high lithium yield, simple process and little environmental pollution.
(2) The method for preparing lithium carbonate by utilizing the lithium-containing waste residue provided by the invention can obtain battery-grade lithium carbonate and has high added value.
(3) The method for preparing lithium carbonate by using the lithium-containing waste residue provided by the invention has the advantages that the acid consumption is small, iron ions are not leached in the leaching process, the key steps are omitted for subsequent impurity removal, and the reagent consumption is reduced.
(4) According to the method for preparing lithium carbonate by utilizing the lithium-containing waste residues, impurities such as calcium, magnesium and phosphorus are removed efficiently by adopting a mode of combining a chemical method and a resin method for removing impurities.
(5) The battery grade lithium carbonate prepared by the method for preparing lithium carbonate by using the lithium-containing waste residue is used as a preparation raw material for preparing the lithium ion battery, so that the production cost of the lithium ion battery can be obviously reduced.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present invention, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.
Fig. 1 is a process flow chart of a method for preparing lithium carbonate by using lithium-containing waste residues according to example 1 of the present invention.
Detailed Description
The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and detailed description, but it will be understood by those skilled in the art that the examples described below are some, but not all, examples of the present invention, and are intended to be illustrative of the present invention only and should not be construed as limiting the scope of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention. The specific conditions are not noted in the examples and are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.
According to the method for preparing lithium carbonate by utilizing the lithium-containing waste residues, namely the method for recycling lithium carbonate from the lithium-containing waste residues, which is used for solving the problem of waste of lithium resources caused by the lithium-phosphorus-iron waste residues generated after treatment of lithium iron phosphate production wastewater, comprises the main components of the lithium-containing waste residues obtained after flocculation precipitation treatment of sewage generated in the process of producing lithium iron phosphate, and impurity elements such as iron, calcium and magnesium, wherein the content of the lithium element in the lithium-containing waste residues is 2500-3500 mg/kg. The method for preparing lithium carbonate by using the lithium-containing waste residues specifically comprises the following steps:
step (1), mixing lithium-containing waste residues, acid and oxidant, and leaching to leach out lithium elements, wherein the main reactions during leaching are as follows:
2LiFePO 4 +H 2 SO 4 +H 2 O 2 ＝2FePO 4 ↓+2H 2 O+Li 2 SO 4 。
in the embodiment of the invention, iron ions are not leached in the leaching process, solid-liquid separation is carried out after leaching is finished, leaching liquid (namely filtrate) and leaching waste residue (namely filter residue) are respectively obtained, and the leaching liquid containing lithium and no iron is reserved for subsequent impurity removal, so that a critical step is omitted for subsequent impurity removal, the consumption of reagents is reduced, and the leaching waste residue can be used for extracting and preparing ferric phosphate.
Step (2), mixing the leaching solution obtained in the step (1) with a impurity removing agent to remove calcium ions, magnesium ions and HPO 4 2- Impurities, then solid-liquid separation is carried out to realize the high-efficiency separation of impurities such as calcium, magnesium, phosphorus and the like from the solution, and impurity removing liquid (namely filtrate) and impurity removing waste residue (namely filter residue) are respectively obtained, wherein the impurity removing liquid is used for subsequent reaction and impurity removingP in waste residue 2 O 5 Content of>12wt.% of the fertilizer can be used for subsequent phosphoric acid production or as fertilizer.
The calcium ions and the magnesium ions in the step (2) are excessive relative to the phosphate radical, so that the phosphate radical is thoroughly removed; and because the calcium and magnesium ions are excessive, the resin method is adopted to remove the calcium and magnesium impurities in the step (3).
And (3) removing residual calcium ion and magnesium ion impurities from the impurity removing liquid through ion exchange resin to obtain lithium-rich liquid with the main component of lithium ions.
And (4) mixing the lithium-rich liquid with carbonate, and performing a lithium precipitation reaction, namely generating a precipitation reaction of lithium carbonate, and performing solid-liquid separation after the lithium precipitation reaction is completed to obtain the lithium carbonate.
In a preferred embodiment, the lithium carbonate comprises battery grade lithium carbonate which can be used for preparing lithium iron phosphate as a positive electrode material of a lithium ion battery, and has high added value.
The invention firstly adopts acid leaching to selectively leach lithium in waste residue, and then removes calcium ions, magnesium ions and HPO from the leaching solution 4 2- And (3) removing impurities from the impurity removing liquid by a resin method, further removing calcium, magnesium and phosphorus impurities to obtain refined lithium-rich liquid, and finally obtaining lithium carbonate by precipitating lithium.
The invention solves the problems of environmental pollution and resource waste caused by waste residues generated in the battery production process. The method has the advantages of simple process flow, low production cost and high lithium yield; realizes the high-efficiency recycling of lithium ferrophosphorus waste slag, has high resource utilization rate, high added value, little environmental pollution and environmental protection.
In a preferred embodiment, in the step (1), the acid includes concentrated sulfuric acid. The calcium content of the lithium-containing waste residue is high, and because the calcium sulfate is slightly dissolved, a large amount of sulfate radicals introduced by sulfuric acid leaching can inhibit the dissolution of calcium ions, so that the subsequent impurity removal difficulty is reduced.
When concentrated sulfuric acid is used, calcium impurities in the lithium-containing waste residue are partially dissolved out and react with sulfate ions to generate precipitate, namely Ca 2+ +SO 4 2- ＝CaSO 4 ↓。
In a preferred embodiment, the acid is added in an amount to the ph=3 to 4 of the lithium-containing waste slag, acid and oxidant mixed system, including but not limited to any one of the point values or range values between any two of 3.2, 3.4, 3.5, 3.7, 3.9.
According to the embodiment of the invention, the pH value of the mixture in the leaching treatment process is adjusted to 3-4, so that the leaching of iron ions can be inhibited (the harm of the iron ions to the subsequent RO membrane is avoided). Under the leaching condition, the leaching rate of lithium ions can be kept above 95%, and the leaching rate of iron ions is below 0.05%.
In a preferred embodiment, the ratio of the volume of acid to the mass of lithium-containing waste residue is 1L: 6-9 kg, e.g. 1L:7kg or 1L:8kg.
The acid has the main functions of regulating and controlling pH, avoiding iron dissolution and providing sulfate radical to inhibit calcium dissolution.
The method provided by the embodiment of the invention has the advantages that the acid consumption is small, the iron ions in the leaching link are not leached, the key steps are omitted for the subsequent impurity removal reaction, and the reagent consumption is reduced.
The lithium iron phosphate has stable structure, the lithium is arranged at the right center of the 8-face body lattice of the lithium iron phosphate, and the oxidant is used for oxidizing the lithium iron phosphate to destroy the lithium iron phosphate lattice and release the lithium in the lattice.
In a preferred embodiment, in the step (1), the oxidizing agent includes a hydrogen peroxide solution.
The hydrogen peroxide solution is adopted as the oxidant, so that other impurity ions are not introduced; lithium in the waste residue mainly exists in the form of lithium iron phosphate, the chemical property of the lithium iron phosphate is particularly stable, the Fenton reaction can be carried out between hydrogen peroxide and iron ions in the waste residue to improve the oxidability, the crystal lattice of the lithium iron phosphate is damaged, and the recovery rate of the lithium is further improved.
In a preferred embodiment, the mass fraction of hydrogen peroxide in the hydrogen peroxide solution (meaning the aqueous hydrogen peroxide solution, i.e. hydrogen peroxide) is 20% to 30%, for example 22%, 24%, 25%, 27% or 29%.
In a preferred embodiment, water is also added in the mixing process of the lithium-containing waste residue, the acid and the oxidant, and the solid-liquid ratio (the ratio of the solid phase mass to the liquid phase volume in the mixture) is controlled to be 1: 6-15 g/ml.
The contact area among the lithium-containing waste residues, the acid and the oxidant can be increased by adding water, the reaction rate is accelerated, lithium ions are leached into the water, and the lithium-containing leaching solution can be obtained through filtration.
By adopting the solid-liquid ratio in the range, the water consumption and the water heating energy consumption can be saved. If the water quantity is too small, stirring and reacting are not uniform; if the water amount is too large, the water consumption and the heating energy consumption are increased.
In a preferred embodiment, the volume of oxidant is 1% to 5%, such as 2%, 3% or 4% of the volume of water added as described above.
In a preferred embodiment, in the step (1), the temperature of the leaching process (i.e. the temperature of the mixture during the leaching process) is 40 to 60 ℃, including but not limited to any one of 45 ℃, 50 ℃, 55 ℃ or a range between any two.
In a preferred embodiment, the time of the leaching process is 3 to 8 hours, including but not limited to a point value of any one of 4 hours, 5 hours, 6 hours, 7 hours, or a range value between any two.
The leaching temperature is adopted, so that the leaching rate is improved.
In a preferred embodiment, during the leaching process, the mixture is stirred at a rotation speed of 400 to 1000rpm, for example 500rpm, 600rpm, 700rpm, 800rpm or 900rpm, in order to increase the leaching efficiency.
In a preferred embodiment, in the step (2), the impurity removing agent includes an alkali and/or ammonia source.
In a preferred embodiment, the ammonia source comprises at least one of ammonia gas, an aqueous ammonia solution, an ammonium carbonate solution, and an ammonium bicarbonate solution.
Ammonia gas and/or ammonium ion are introduced, and react with phosphorus impurities and magnesium impurities to form magnesium ammonium phosphate precipitate, so that the purpose of removing phosphorus and magnesium impurities is achieved. Introducing carbonate ions to facilitate the removal of calcium due to lithium carbonate and calcium carbonate k sp The phase difference is very large, so lithium is not lost.
In a preferred embodiment, the base comprises at least one of sodium hydroxide, sodium hydroxide and lithium hydroxide. More preferably sodium hydroxide, which is low cost.
In a preferred embodiment, in step (2), in order to improve the impurity removal efficiency, the impurity removal agent adopts an alkali and an ammonia source, wherein the alkali is mainly used for adjusting the pH value so as to lead calcium ions and magnesium ions to be respectively combined with HPO 4 2- And/or OH - The precipitate is formed and the ammonia source is mainly used for providing NH 4 + To remove magnesium ions, calcium ions, magnesium ions and HPO 4 2- The reactions that mainly occur during impurities include:
Ca 2+ +HPO 4 2- ＝CaHPO 4 ↓；
3Ca 2+ +2OH - +2HPO 4 2- ＝Ca 3 (PO 4 ) 2 ↓+2H 2 O；
Ca 2+ +CO 3 2- ＝CaCO 3 ↓；
Mg 2+ +NH 3 ·H 2 O+HPO 4 2- ＝H 2 O+Mg(NH 4 )PO 4 ↓；
Mg 2+ +HPO 4 2- ＝MgHPO 4 ↓；
Mg 2+ +2OH - ＝Mg(OH) 2 ↓；
3Mg 2+ +2OH - +2HPO 4 2- ＝Mg 3 (PO 4 ) 2 ↓+2H 2 O。
in a preferred embodiment, the molar ratio of the N element (or ammonium ion) in the ammonia source to the magnesium element in the leachate is 0.7-1.5: 1, for example 0.8:1, 0.9:1, 1:1, 1.2:1 or 1.4:1.
In a preferred embodiment, in the step (2), the calcium ion, magnesium ion and HPO are removed 4 2- The pH of the impurity system is 8.5-9.5,including but not limited to a point value of any one of 8.7, 8.8, 9.0, 9.2, 9.4 or a range value therebetween.
Removing calcium ions, magnesium ions and HPO from the mixed system of the leaching solution and the impurity removing agent in the step (2) 4 2- The pH of the impurity is 8.5-9.5, and the lithium phosphate precipitation can be avoided, so that the lithium yield is reduced.
In a preferred embodiment, calcium, magnesium and HPO are removed 4 2- The reaction time of the impurity is 1 to 5 hours, including but not limited to any one of the point values of 2 hours, 3 hours and 4 hours or a range value between any two.
In a preferred embodiment, in step (3), the method further comprises a step of first concentrating the impurity removing solution before removing residual calcium ion and magnesium ion impurities by the ion exchange resin in order to increase the lithium ion concentration.
In a preferred embodiment, in the step (4), in order to further increase the concentration of lithium ions so as to complete the lithium precipitation reaction, the step of concentrating the lithium-rich solution for the second time is further included before the lithium precipitation reaction.
In a preferred embodiment, the first concentration comprises RO concentration (i.e., reverse osmosis concentration), the RO concentration power consumption is about 1/20 of the evaporation concentration power consumption, and thus the concentration cost can be reduced by adopting RO concentration for the first concentration.
In a preferred embodiment, the RO membrane used for RO concentration is a high pressure sea water desalination membrane, and the operating pressure of RO concentration is 4-8 Mpa, including but not limited to any one of 5Mpa, 6Mpa, 7Mpa, or a range between any two.
In a preferred embodiment, the pH of the decontaminating solution is adjusted to a pH of 5 to 6, including but not limited to a point value of any one of 5.3, 5.5, 5.8 or a range value between any two, prior to RO concentration.
In a preferred embodiment, to provide better operation of the RO apparatus, and to avoid damage to the apparatus from calcium ion scaling, the RO is concentrated to a TDS (total dissolved solids) of 50 to 60g/L for the decontaminated liquid, including but not limited to a point value of any one of 53g/L, 55g/L, 58g/L, or a range of values between any two.
In a preferred embodiment, the second concentrating comprises evaporative concentration. The concentration efficiency of evaporation concentration is high, and the lithium-rich liquid with high concentration is obtained, so that the lithium precipitation efficiency is improved.
In a preferred embodiment, the concentration by evaporation is such that the lithium element content in the lithium-rich liquid is 15-30 g/L, including but not limited to a point value of any one of 20g/L, 23g/L, 25g/L, 28g/L or a range value between any two.
In a preferred embodiment, in the step (3), in order to further remove the impurity elements such as calcium, magnesium, iron, etc. remaining in the impurity removing liquid and to improve the impurity removing efficiency, the ion exchange resin is a chelate ion exchange resin.
In a preferred embodiment, the volume of water fed during the removal of residual calcium and magnesium ion impurities using ion exchange resins is 60-200 times the volume of the ion exchange resin, including but not limited to any one of 80 times, 100 times, 150 times, 180 times, or any range between the two; the water inflow velocity is 5-15 BV/h, including but not limited to any one point value or range value between any two of 8BV/h, 10BV/h and 13 BV/h; the pH of the inlet water is controlled to be 7.0-8.5, including but not limited to any one point value or range value between any two of 7.3, 7.5, 7.8, 8.0 and 8.3.
In a preferred embodiment, in the step (4), the temperature of the lithium precipitation reaction (i.e. the temperature of the mixture during the lithium precipitation reaction) is 80-100 ℃, including, but not limited to, any one of the point values or any range between the two values of 85 ℃, 90 ℃ and 95 ℃.
In a preferred embodiment, the time of the lithium precipitation reaction is 1 to 5 hours, including but not limited to a point value of any one of 2 hours, 3 hours, 4 hours or a range value between any two.
In a preferred embodiment, after solid-liquid separation after the lithium precipitation reaction, the method further comprises the step of washing and drying the obtained lithium carbonate in sequence, wherein the washed and dried lithium carbonate is battery grade lithium carbonate. Wherein, water with the temperature of 80-90 ℃ is adopted for washing, and the volume of the water is 2-5 times of that of the lithium carbonate.
In a preferred embodiment, the carbonate comprises at least one of sodium carbonate, potassium carbonate and ammonium carbonate.
In a preferred embodiment, pure water obtained after RO concentration and/or evaporation concentration can be recycled to step (1) for leaching treatment.
According to the method, through the combination of chemical impurity removal and resin impurity removal, the content of impurity elements such as calcium, magnesium, phosphorus and the like can be reduced to below 10ppm through detection, and lithium precipitation is carried out on refined lithium-rich liquid obtained in the process, so that the standard of battery-grade lithium carbonate can be achieved.
In a second aspect, the invention provides an application of the lithium carbonate prepared by the method for preparing lithium carbonate by using lithium-containing waste residues in a lithium ion battery.
The battery grade lithium carbonate prepared by the method for preparing lithium carbonate by using the lithium-containing waste residues can be used as a raw material for preparing the anode material of the lithium ion battery, and the waste lithium-containing waste residues are used for preparing the battery grade lithium carbonate, so that not only can the waste of lithium resources be avoided, but also the production cost of the lithium ion battery is reduced.
Embodiments of the present invention will be described in detail below with reference to examples, but it will be understood by those skilled in the art that the following examples are only for illustrating the present invention and should not be construed as limiting the scope of the present invention. The specific conditions are not noted in the examples and are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.
The lithium element content in the lithium-containing waste slag used in the following examples of the present invention was about 3000mg/kg (i.e., about 3000mg of lithium element per kg of lithium-containing waste slag).
Example 1
The method for preparing lithium carbonate by using the lithium-containing waste residues provided by the embodiment comprises the following steps:
adding water to lithium-containing waste residues until the solid-to-liquid ratio is 1:10g/ml, and then adding 98% by mass of concentrated sulfuric acid and 27% by mass of hydrogen peroxide solution into the mixture, wherein the ratio of the volume of the concentrated sulfuric acid to the mass of the lithium-containing waste residues is 1L:8.5kg, wherein the volume of the hydrogen peroxide solution is 3% of the volume of the added water, leaching treatment is carried out under the condition that the pH is 3.1, the reaction temperature of the leaching treatment is controlled to be 60 ℃, the stirring speed is 500rpm, and solid-liquid separation is carried out after the reaction for 4 hours, so that leaching liquid is obtained, the leaching rate of lithium ions is 96.7%, and the leaching rate of iron ions is 0.03%;
step (2), adding an ammonia water solution with the mass fraction of 22% into the leaching solution obtained in the step (1), so that the molar ratio of ammonium ions in the ammonia water solution to magnesium ions in the leaching solution is 0.8:1, and adding 2mol/L sodium hydroxide solution to control the pH value to 8.9, and removing calcium ion, magnesium ion and HPO 4 2- Carrying out solid-liquid separation on impurities after reacting for 1h to obtain impurity-removing liquid;
step (3), after the pH value of the impurity removal liquid obtained in the step (2) is adjusted to 5.5, performing first concentration through an RO membrane (high pressure sea water desalination membrane), wherein the pressure of RO concentration is 6Mpa, so as to obtain a concentrated liquid, and TDS=55.4 g/L of the concentrated liquid;
step (4), after regulating the pH value of the concentrated solution obtained in the step (3) to 7.5, passing through an ion exchange resin tower (the resin used is chelating ion exchange resin, specifically Dusheng resin CH-90), and removing residual calcium ion and magnesium ion impurities, wherein the volume of water is 60 times of that of the resin, the water inflow flow rate is 10BV/h, so as to obtain refined lithium-rich mother solution (namely lithium-rich solution), and detecting that the content of magnesium element in the refined lithium-rich mother solution is 2.8ppm, the content of calcium element is 1.9ppm, and the content of phosphorus element is less than 3.7ppm;
concentrating (namely second concentrating) the refined lithium-rich mother liquor obtained in the step (5) and the step (4) through an evaporator to obtain refined lithium-precipitating mother liquor, wherein the content of lithium element in the refined lithium-precipitating mother liquor is 16.5g/L;
adding a sodium carbonate solution with the mass fraction of 30% into the refined lithium precipitation mother solution obtained in the step (5), enabling the molar ratio of carbonate ions in the sodium carbonate solution to lithium ions in the refined lithium precipitation mother solution to be 1.1:2, carrying out lithium precipitation reaction at the reaction temperature of 90 ℃, stirring at the rotation speed of 400rpm, aging for 1.5h after the reaction is carried out for 2h, and carrying out solid-liquid separation to obtain crude lithium carbonate; and adding 90 ℃ hot water with the mass being 2 times that of the crude lithium carbonate, performing secondary water washing and drying to obtain battery grade lithium carbonate, wherein the lithium yield of the embodiment is 83.7%.
And (3) RO concentration and pure water obtained after evaporation concentration in the step (5) are recycled to the next step (1) for preparing lithium carbonate, and are used as water sources for leaching treatment. And recovering the leaching waste residue obtained after the solid-liquid separation in the step (1) for extracting ferric phosphate; and (3) recycling the impurity-removed waste residue obtained after the solid-liquid separation in the step (2) for preparing phosphoric acid or serving as a chemical fertilizer.
The process flow chart of the method for preparing lithium carbonate by using the lithium-containing waste residues provided by the embodiment is shown in fig. 1.
Example 2
The method for preparing lithium carbonate by using the lithium-containing waste residues provided by the embodiment comprises the following steps:
adding water to lithium-containing waste residues until the solid-to-liquid ratio is 1:8g/ml, and then adding 98% by mass of concentrated sulfuric acid and 25% by mass of hydrogen peroxide solution into the solution, wherein the ratio of the volume of the concentrated sulfuric acid to the mass of the lithium-containing waste residues is 1L:8kg, wherein the volume of the hydrogen peroxide solution is 4% of the volume of the added water, leaching treatment is carried out under the condition that the pH is 3.2, the reaction temperature of the leaching treatment is controlled to be 60 ℃, the stirring speed is 450rpm, and solid-liquid separation is carried out after the reaction for 4 hours, so that a leaching solution is obtained, the leaching rate of lithium ions is 95.8%, and the leaching rate of iron ions is 0.04%;
step (2), adding an ammonia water solution with the mass fraction of 22% and an ammonium bicarbonate solution with the mass fraction of 10% into the leaching solution obtained in the step (1), so that the molar ratio of total ammonium ions in the ammonia water solution and the ammonium bicarbonate solution to magnesium ions in the leaching solution is 1:1, and adding 2mol/L sodium hydroxide solution to control the pH value to 9.0, removing calcium ion, magnesium ion and HPO 4 2- Carrying out solid-liquid separation on impurities after reacting for 1.5 hours to obtain impurity-removing liquid;
step (3), after the pH value of the impurity removal liquid obtained in the step (2) is regulated to 6.0, performing first concentration through an RO membrane (high pressure sea water desalination membrane), wherein the pressure of RO concentration is 5.8Mpa, so as to obtain a concentrated liquid, and TDS=54 g/L of the concentrated liquid;
step (4), after regulating the pH value of the concentrated solution obtained in the step (3) to 8.0, passing through an ion exchange resin tower (the resin used is chelating ion exchange resin, specifically being Dusheng resin CH-90), and removing residual calcium ion and magnesium ion impurities, wherein the volume of water is 80 times of that of the resin, the water inflow flow rate is 12BV/h, so as to obtain refined lithium-rich mother liquor (namely lithium-rich liquor), and detecting that the content of magnesium element in the refined lithium-rich mother liquor is 5.1ppm, the content of calcium element is 4.5ppm, and the content of phosphorus element is less than 6.2ppm;
concentrating (namely second concentrating) the refined lithium-rich mother liquor obtained in the step (5) and the step (4) through an evaporator to obtain refined lithium-precipitating mother liquor, wherein the content of lithium element in the refined lithium-precipitating mother liquor is 16.7g/L;
adding a sodium carbonate solution with the mass fraction of 20% into the refined lithium precipitation mother solution obtained in the step (5), enabling the molar ratio of carbonate ions in the sodium carbonate solution to lithium ions in the refined lithium precipitation mother solution to be 1.1:2, carrying out lithium precipitation reaction at the reaction temperature of 90 ℃, stirring at the rotation speed of 450rpm, aging for 1.5h after the reaction is carried out for 2h, and carrying out solid-liquid separation to obtain crude lithium carbonate; and adding hot water with the mass of 90 ℃ which is 3 times that of the crude lithium carbonate, performing secondary water washing, and drying to obtain battery grade lithium carbonate, wherein the lithium yield of the embodiment is 81.8%.
Example 3
The method for preparing lithium carbonate by using the lithium-containing waste residues provided by the embodiment comprises the following steps:
adding water to lithium-containing waste residues until the solid-to-liquid ratio is 1:12g/ml, and then adding 98% by mass of concentrated sulfuric acid and 27% by mass of hydrogen peroxide solution into the mixture, wherein the ratio of the volume of the concentrated sulfuric acid to the mass of the lithium-containing waste residues is 1L:8.5kg, wherein the volume of the hydrogen peroxide solution is 4% of the volume of the added water, leaching treatment is carried out under the condition that the pH value is 3.4, the reaction temperature of the leaching treatment is controlled to be 50 ℃, the stirring speed is 500rpm, and solid-liquid separation is carried out after the reaction for 4 hours, so that leaching liquid is obtained, the leaching rate of lithium ions is 97.1%, and the leaching rate of iron ions is 0.03%;
step (2), adding an ammonia water solution with the mass fraction of 22% and an ammonium carbonate solution with the mass fraction of 10% into the leaching solution obtained in the step (1) to enable the ammonia water solution and the ammonium carbonate solution to be inThe molar ratio of total ammonium ions to magnesium ions in the leaching solution is 1:1, and adding 2mol/L sodium hydroxide solution to control the pH value to 9.0, removing calcium ion, magnesium ion and HPO 4 2- Carrying out solid-liquid separation on impurities after reacting for 1.5 hours to obtain impurity-removing liquid;
step (3), after the pH value of the impurity removal liquid obtained in the step (2) is adjusted to 5.5, performing first concentration through an RO membrane (high pressure sea water desalination membrane), wherein the pressure of RO concentration is 5.6Mpa, so as to obtain a concentrated liquid, and TDS=51.5 g/L of the concentrated liquid;
step (4), after regulating the pH value of the concentrated solution obtained in the step (3) to 8.5, passing through an ion exchange resin tower (the resin used is chelating ion exchange resin, specifically Dusheng resin CH-93) to remove residual calcium ion and magnesium ion impurities, wherein the volume of water is 80 times of that of the resin, the water inflow flow rate is 13BV/h to obtain refined lithium-rich mother solution (namely lithium-rich solution), and detecting that the content of magnesium element in the refined lithium-rich mother solution is 6.2ppm, the content of calcium element is 3.5ppm and the content of phosphorus element is 4.1ppm;
concentrating (namely second concentrating) the refined lithium-rich mother liquor obtained in the step (5) and the step (4) through an evaporator to obtain refined lithium-precipitating mother liquor, wherein the content of lithium element in the refined lithium-precipitating mother liquor is 18.2g/L;
adding 20% sodium carbonate solution into the refined lithium precipitation mother solution obtained in the step (5) to enable the molar ratio of carbonate ions in the sodium carbonate solution to lithium ions in the refined lithium precipitation mother solution to be 1.05:2, carrying out lithium precipitation reaction at 90 ℃, stirring at 500rpm, aging for 2 hours after reacting for 1.5 hours, and carrying out solid-liquid separation to obtain crude lithium carbonate; and adding hot water with the mass of 90 ℃ which is 3 times that of the crude lithium carbonate, performing secondary water washing, and drying to obtain battery grade lithium carbonate, wherein the lithium yield of the embodiment is 82.9%.
Example 4
The method for preparing lithium carbonate by using the lithium-containing waste residues provided by the embodiment comprises the following steps:
adding water to lithium-containing waste residues until the solid-to-liquid ratio is 1:15g/ml, and then adding 98% by mass of concentrated sulfuric acid and 20% by mass of hydrogen peroxide solution into the mixture, wherein the ratio of the volume of the concentrated sulfuric acid to the mass of the lithium-containing waste residues is 1L:7kg, wherein the volume of the hydrogen peroxide solution is 5% of the volume of the added water, leaching treatment is carried out under the condition that the pH is 3.6, the reaction temperature of the leaching treatment is controlled to be 40 ℃, the stirring speed is 400rpm, and after 5 hours of reaction, solid-liquid separation is carried out to obtain leaching solution, the leaching rate of lithium ions is 95.9%, and the leaching rate of iron ions is 0.03%;
step (2), adding an ammonia water solution with the mass fraction of 22% into the leaching solution obtained in the step (1), so that the molar ratio of total ammonium ions in the ammonia water solution and the ammonium bicarbonate solution to magnesium ions in the leaching solution is 1:1, and adding 2mol/L sodium hydroxide solution to control the pH value to 8.9, and removing calcium ion, magnesium ion and HPO 4 2- Carrying out solid-liquid separation on impurities after reacting for 1.5 hours to obtain impurity-removing liquid;
step (3), after the pH value of the impurity removal liquid obtained in the step (2) is adjusted to 5.5, performing first concentration through an RO membrane (high pressure sea water desalination membrane), wherein the pressure of RO concentration is 5.9Mpa, so as to obtain a concentrated liquid, and the TDS=56.1 g/L of the concentrated liquid;
step (4), after regulating the pH value of the concentrated solution obtained in the step (3) to 8.4, passing through an ion exchange resin tower (the resin used is chelating ion exchange resin, specifically Dusheng resin CH-93) to remove residual calcium ion and magnesium ion impurities, wherein the volume of water is 110 times of that of the resin, the water inflow flow rate is 15BV/h to obtain refined lithium-rich mother solution (namely lithium-rich solution), and detecting to obtain the refined lithium-rich mother solution, wherein the content of magnesium element is 4.8ppm, the content of calcium element is 2.3ppm and the content of phosphorus element is 3.7ppm;
concentrating (namely second concentrating) the refined lithium-rich mother liquor obtained in the step (5) and the step (4) through an evaporator to obtain refined lithium-precipitating mother liquor, wherein the content of lithium element in the refined lithium-precipitating mother liquor is 15.9g/L;
adding a sodium carbonate solution with the mass fraction of 20% into the refined lithium precipitation mother solution obtained in the step (5), enabling the molar ratio of carbonate ions in the sodium carbonate solution to lithium ions in the refined lithium precipitation mother solution to be 1.06:2, carrying out lithium precipitation reaction at the reaction temperature of 90 ℃, stirring at the rotation speed of 430rpm, aging for 1.5h after reacting for 2h, and carrying out solid-liquid separation to obtain crude lithium carbonate; and adding hot water with the mass of 90 ℃ which is 3 times that of the crude lithium carbonate, performing secondary water washing, and drying to obtain battery grade lithium carbonate, wherein the lithium yield of the embodiment is 81.9%.
Example 5
The method for preparing lithium carbonate by using the lithium-containing waste residues provided by the embodiment comprises the following steps:
adding water to lithium-containing waste residues until the solid-to-liquid ratio is 1:15g/ml, and then adding 98% by mass of concentrated sulfuric acid and 30% by mass of hydrogen peroxide solution into the mixture, wherein the ratio of the volume of the concentrated sulfuric acid to the mass of the lithium-containing waste residues is 1L:7.5kg, wherein the volume of the hydrogen peroxide solution is 3.5% of the volume of the added water, leaching treatment is carried out under the condition that the pH value is 3.7, the reaction temperature of the leaching treatment is controlled to be 40 ℃, the stirring speed is 1000rpm, and after 5.5 hours of reaction, solid-liquid separation is carried out, so that leaching liquid is obtained, the leaching rate of lithium ions is 96.2%, and the leaching rate of iron ions is 0.02%;
step (2), adding an ammonia water solution with the mass fraction of 22% and an ammonium carbonate solution with the mass fraction of 10% into the leaching solution obtained in the step (1), so that the molar ratio of total ammonium ions in the ammonia water solution and the ammonium carbonate solution to magnesium ions in the leaching solution is 1:1, and adding 2mol/L sodium hydroxide solution to control the pH value to 9.0, removing calcium ion, magnesium ion and HPO 4 2- Carrying out solid-liquid separation on impurities after reacting for 1.5 hours to obtain impurity-removing liquid;
step (3), after the pH value of the impurity removal liquid obtained in the step (2) is adjusted to 5.3, performing first concentration through an RO membrane (high pressure sea water desalination membrane), wherein the pressure of RO concentration is 6Mpa, so as to obtain a concentrated liquid, and TDS=56.9 g/L of the concentrated liquid;
step (4), after regulating the pH value of the concentrated solution obtained in the step (3) to 8.5, passing through an ion exchange resin tower (the resin used is chelating ion exchange resin, specifically being Dusheng resin CH-90), and removing residual calcium ion and magnesium ion impurities, wherein the volume of water is 150 times of that of the resin, the water inflow flow rate is 15BV/h, so as to obtain refined lithium-rich mother liquor (namely lithium-rich liquor), and detecting to obtain the refined lithium-rich mother liquor, wherein the magnesium element content is 7.8ppm, the calcium element content is 4.1ppm and the phosphorus element content is 3.4ppm;
concentrating (namely second concentrating) the refined lithium-rich mother liquor obtained in the step (5) and the step (4) through an evaporator to obtain refined lithium-precipitating mother liquor, wherein the content of lithium element in the refined lithium-precipitating mother liquor is 17.5g/L;
adding a sodium carbonate solution with the mass fraction of 20% into the refined lithium precipitation mother solution obtained in the step (5), enabling the molar ratio of carbonate ions in the sodium carbonate solution to lithium ions in the refined lithium precipitation mother solution to be 1.07:2, carrying out lithium precipitation reaction at the reaction temperature of 85 ℃, stirring at the rotation speed of 460rpm, aging for 1.5h after the reaction is carried out for 1.5h, and carrying out solid-liquid separation to obtain crude lithium carbonate; and adding 90 ℃ hot water with the mass of 4 times to the crude lithium carbonate, performing secondary water washing and drying to obtain battery grade lithium carbonate, wherein the lithium yield of the embodiment is 82.2%.
Example 6
The method for preparing lithium carbonate by using the lithium-containing waste residue provided in this example is basically the same as that of example 5, except that in step (1), leaching treatment is performed under the condition of pH 3.8, and the lithium yield of this example is 81.1%.
Example 7
The method for producing lithium carbonate using the lithium-containing waste residue according to this example is substantially the same as in example 5, except that in step (2), the removal of calcium ions, magnesium ions and HPO is controlled 4 2- The pH during the impurity procedure was 9.1 and the lithium yield of this example was 82.1%.
Comparative example 1
The method for producing lithium carbonate using lithium-containing waste residue provided in this comparative example was substantially the same as in example 5, except that in step (1), leaching treatment was performed at a pH of 2.0.
Comparative example 2
The method for producing lithium carbonate using the lithium-containing waste residue provided in this comparative example was substantially the same as in example 5, except that in step (1), a hydrogen peroxide solution was not added.
The comparative example had a lithium ion leaching rate reduced due to the absence of the oxidizing agent, and the lithium yield of the comparative example was 47.1%.
Comparative example 3
The method for preparing lithium carbonate using the lithium-containing waste residue provided in this comparative example was substantially the same as in example 5, except that in step (2), an aqueous ammonia solution and an ammonium bicarbonate solution were not added.
Comparative example 4
The method for preparing lithium carbonate using lithium-containing waste residue provided in this comparative example is substantially the same as in example 5, except that the RO concentration of step (3) and the evaporation concentration of step (5) are not performed. Since the intermediate liquid is not concentrated, resulting in low lithium concentration of the refined lithium-rich mother liquid obtained after removing residual calcium ion and magnesium ion impurities, lithium carbonate precipitate cannot be formed in the lithium precipitation process, and thus battery grade lithium carbonate is not obtained in this comparative example.
Comparative example 5
The comparative example provides a method for preparing lithium carbonate using lithium-containing waste residue substantially the same as in example 5, except that the step (4) of removing residual calcium and magnesium ion impurities is not performed (i.e., the concentrated solution is not passed through the ion exchange resin column).
Comparative example 6
The method for preparing lithium carbonate by using the lithium-containing waste residue is basically the same as that of example 5, except that in the step (2), the leaching solution is controlled to be mixed with a impurity removing agent to remove calcium ions, magnesium ions and HPO 4 2- The pH of the impurity system was 10.5.
In this comparative example, calcium ion, magnesium ion and HPO are removed by controlling the mixture of the leachate and the impurity removing agent 4 2- Too high a pH of the impurity system results in the formation of lithium phosphate precipitates, resulting in a decrease in lithium carbonate yield to 69.6%.
Experimental example 1
The impurity contents in the battery-grade lithium carbonate prepared in each of the above examples and the lithium carbonate prepared in each of the comparative examples were separately examined, and the results are shown in table 1.
TABLE 1 impurity element content in lithium carbonate
As can be seen from Table 1, the impurity content in the lithium carbonate prepared in each example meets the standard of battery grade lithium carbonate, and therefore, the method for preparing lithium carbonate by using lithium-containing waste residue provided by the invention can obtain battery grade lithium carbonate, and has high added value and high resource utilization rate.
In contrast, comparative example 1 leached iron due to too low pH during leaching, resulting in a higher iron content in the lithium carbonate produced. In comparative example 3, the impurity removal efficiency is low because no ammonia source is added in the chemical impurity removal process, so that the content of calcium and magnesium impurities in the prepared lithium carbonate is high. Comparative example 5 has higher contents of calcium and magnesium impurities in the prepared lithium carbonate because the resin impurity removal is not performed.
Therefore, the method for preparing lithium carbonate by utilizing the lithium-containing waste residue provided by the invention can efficiently remove impurities such as calcium, magnesium, phosphorus and the like by adopting a mode of combining a chemical method and a resin method for removing impurities, and the battery-grade lithium carbonate with low impurity content and meeting the requirements is obtained.
While the invention has been illustrated and described with reference to specific embodiments, it is to be understood that the above embodiments are merely illustrative of the technical aspects of the invention and not restrictive thereof; those of ordinary skill in the art will appreciate that: modifications may be made to the technical solutions described in the foregoing embodiments, or equivalents may be substituted for some or all of the technical features thereof, without departing from the spirit and scope of the present invention; such modifications and substitutions do not depart from the spirit of the corresponding technical solutions; it is therefore intended to cover in the appended claims all such alternatives and modifications as fall within the scope of the invention.
Claims (10)
1. The method for preparing lithium carbonate by using the lithium-containing waste residue is characterized by comprising the following steps:
mixing lithium-containing waste residues, acid and an oxidant, and performing leaching treatment, and performing solid-liquid separation to obtain a lithium-containing leaching solution, wherein the leaching rate of lithium ions in the leaching solution is more than 95%, and the leaching rate of iron ions is less than 0.05%;
mixing the leaching solution with impurity removing agent to remove calcium ion, magnesium ion and HPO 4 2- Impurity, solid-liquid separation to obtainLithium-containing impurity removing liquid;
removing residual calcium ion and magnesium ion impurities from the impurity removing liquid through ion exchange resin to obtain lithium-rich liquid;
and carrying out solid-liquid separation to obtain lithium carbonate after lithium precipitation reaction between the lithium-rich liquid and carbonate.
2. The method for preparing lithium carbonate by using lithium-containing waste residue according to claim 1, wherein the acid comprises concentrated sulfuric acid;
and/or the addition amount of the acid is to the pH=3-4 of the lithium-containing waste residue, acid and oxidant mixed system.
3. The method for preparing lithium carbonate using lithium-containing waste residue according to claim 1, wherein the oxidizing agent comprises a hydrogen peroxide solution.
4. The method for preparing lithium carbonate by using lithium-containing waste residue according to claim 1, wherein the leaching treatment temperature is 40-60 ℃;
and/or the leaching treatment time is 3-8 h.
5. The method for preparing lithium carbonate by using lithium-containing waste residue according to claim 1, wherein the impurity removing agent comprises at least one of an alkali and an ammonia source;
and/or mixing the leaching solution with a impurity removing agent to remove calcium ions, magnesium ions and HPO 4 2- The pH value of the impurity system is 8.5-9.5;
and/or, the removal of calcium ions, magnesium ions and HPO 4 2- The impurity time is 1-5 h.
6. The method for preparing lithium carbonate by using lithium-containing waste residue according to claim 1, wherein the impurity removing liquid is subjected to a first concentration step before residual calcium ion and magnesium ion impurities are removed by ion exchange resin;
and/or, before the lithium precipitation reaction, the method further comprises the step of carrying out second concentration on the lithium-rich liquid.
7. The method for preparing lithium carbonate using lithium-containing waste residue according to claim 6, wherein the first concentrating comprises RO concentrating;
and/or, the second concentrating comprises evaporative concentration.
8. The method for preparing lithium carbonate using lithium-containing waste residue according to claim 1, wherein the ion exchange resin comprises a chelating ion exchange resin.
9. The method for preparing lithium carbonate by using lithium-containing waste residue according to claim 1, wherein the temperature of the lithium precipitation reaction is 80-100 ℃;
and/or the time of the lithium precipitation reaction is 1-5 h.
10. Use of the lithium carbonate produced by the method for producing lithium carbonate using lithium-containing waste residue according to any one of claims 1 to 9 in lithium ion batteries.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310791764.6A CN116835614A (en) | 2023-06-29 | 2023-06-29 | Method for preparing lithium carbonate by using lithium-containing waste residues and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310791764.6A CN116835614A (en) | 2023-06-29 | 2023-06-29 | Method for preparing lithium carbonate by using lithium-containing waste residues and application thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116835614A true CN116835614A (en) | 2023-10-03 |
Family
ID=88164680
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310791764.6A Pending CN116835614A (en) | 2023-06-29 | 2023-06-29 | Method for preparing lithium carbonate by using lithium-containing waste residues and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116835614A (en) |
-
2023
- 2023-06-29 CN CN202310791764.6A patent/CN116835614A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109554545B (en) | Method for selectively extracting lithium from lithium iron phosphate waste | |
| JP2023522088A (en) | Comprehensive recovery and utilization method for used lithium iron phosphate batteries | |
| CN113896211B (en) | Treatment method for funding waste lithium iron phosphate battery | |
| JP2011168461A (en) | Method for producing high-concentration lithium liquid from lithium-containing liquid and method for producing lithium carbonate | |
| JP2019533628A (en) | Method for producing lithium compound | |
| KR102035712B1 (en) | Method of preparing lithium compound | |
| CN104944400A (en) | Technology for preparing iron phosphate through hydrolytic method | |
| CN114655969B (en) | Method for preparing lithium carbonate and iron phosphate by recycling high-impurity lithium iron phosphate positive electrode waste material | |
| CN113354177B (en) | System and method for recycling iron phosphate ammonia nitrogen-containing wastewater | |
| CN113415793B (en) | Method for preparing high-purity iron phosphate from lithium iron phosphate battery waste | |
| CN110835683A (en) | Method for selectively extracting lithium from waste lithium ion battery material | |
| JP2020132951A (en) | Lithium recovery method | |
| CN109534372A (en) | The method for preparing lithium carbonate using LiFePO4 waste material | |
| CN112645396B (en) | Method for treating fluorine-containing nickel slag generated in nitrogen trifluoride preparation process | |
| KR101973475B1 (en) | Manufacturing Method of Controlling Size and High Purity Lithium Carbonate Using Lithium Sulfate and Low Purity Barium Hydroxide | |
| CN112850679A (en) | Method for preparing iron phosphate by using waste acid | |
| CN116835614A (en) | Method for preparing lithium carbonate by using lithium-containing waste residues and application thereof | |
| CN217323729U (en) | System for ferric phosphate contains full element resourceful treatment of ammonia nitrogen waste water | |
| CN115637326A (en) | Waste phosphoric acid etching solution and decommissioned LiFePO 4 Power battery co-processing method | |
| CN210560650U (en) | Reaction device | |
| CN112011692A (en) | Method for extracting vanadium by composite roasting of solid waste slag | |
| CN219972063U (en) | Treatment system for waste water in iron phosphate production | |
| CN112758962B (en) | Method for treating lithium ion-containing solution with pH value less than 4 | |
| CN112777580B (en) | Industrial method for treating substance containing lithium iron phosphate | |
| KR102466505B1 (en) | Manufacturing method of lithium compound |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |