CN118086678A - Method for recovering valuable metals in magnesium-containing wastewater - Google Patents
Method for recovering valuable metals in magnesium-containing wastewater Download PDFInfo
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- CN118086678A CN118086678A CN202410193658.2A CN202410193658A CN118086678A CN 118086678 A CN118086678 A CN 118086678A CN 202410193658 A CN202410193658 A CN 202410193658A CN 118086678 A CN118086678 A CN 118086678A
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- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 title claims abstract description 206
- 239000011777 magnesium Substances 0.000 title claims abstract description 206
- 229910052749 magnesium Inorganic materials 0.000 title claims abstract description 206
- 239000002351 wastewater Substances 0.000 title claims abstract description 124
- 229910052751 metal Inorganic materials 0.000 title claims abstract description 69
- 239000002184 metal Substances 0.000 title claims abstract description 67
- 150000002739 metals Chemical class 0.000 title claims abstract description 56
- 238000000034 method Methods 0.000 title claims abstract description 50
- 238000000605 extraction Methods 0.000 claims abstract description 234
- 239000007788 liquid Substances 0.000 claims abstract description 124
- 229910017052 cobalt Inorganic materials 0.000 claims abstract description 74
- 239000010941 cobalt Substances 0.000 claims abstract description 74
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims abstract description 74
- 239000000284 extract Substances 0.000 claims abstract description 62
- 239000000243 solution Substances 0.000 claims abstract description 58
- 239000012266 salt solution Substances 0.000 claims abstract description 49
- 238000002156 mixing Methods 0.000 claims abstract description 45
- 229910003002 lithium salt Inorganic materials 0.000 claims abstract description 21
- 159000000002 lithium salts Chemical class 0.000 claims abstract description 21
- 150000002815 nickel Chemical class 0.000 claims abstract description 16
- 150000001868 cobalt Chemical class 0.000 claims abstract description 10
- 159000000003 magnesium salts Chemical class 0.000 claims abstract description 10
- 230000001105 regulatory effect Effects 0.000 claims abstract description 9
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 94
- 229910052759 nickel Inorganic materials 0.000 claims description 47
- 238000007127 saponification reaction Methods 0.000 claims description 31
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims description 23
- 229910052744 lithium Inorganic materials 0.000 claims description 23
- 238000002386 leaching Methods 0.000 claims description 21
- QUXFOKCUIZCKGS-UHFFFAOYSA-N bis(2,4,4-trimethylpentyl)phosphinic acid Chemical compound CC(C)(C)CC(C)CP(O)(=O)CC(C)CC(C)(C)C QUXFOKCUIZCKGS-UHFFFAOYSA-N 0.000 claims description 18
- 238000001556 precipitation Methods 0.000 claims description 18
- 239000003513 alkali Substances 0.000 claims description 15
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 14
- 239000000843 powder Substances 0.000 claims description 14
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 claims description 10
- 239000013067 intermediate product Substances 0.000 claims description 10
- 239000012452 mother liquor Substances 0.000 claims description 9
- 229910000029 sodium carbonate Inorganic materials 0.000 claims description 5
- 229910052979 sodium sulfide Inorganic materials 0.000 claims description 4
- GRVFOGOEDUUMBP-UHFFFAOYSA-N sodium sulfide (anhydrous) Chemical compound [Na+].[Na+].[S-2] GRVFOGOEDUUMBP-UHFFFAOYSA-N 0.000 claims description 4
- 238000004064 recycling Methods 0.000 abstract description 6
- 239000012071 phase Substances 0.000 description 137
- 238000011084 recovery Methods 0.000 description 45
- 239000012535 impurity Substances 0.000 description 21
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 20
- 238000000926 separation method Methods 0.000 description 20
- 239000003795 chemical substances by application Substances 0.000 description 15
- 239000000047 product Substances 0.000 description 14
- 230000008569 process Effects 0.000 description 11
- SEGLCEQVOFDUPX-UHFFFAOYSA-N di-(2-ethylhexyl)phosphoric acid Chemical compound CCCCC(CC)COP(O)(=O)OCC(CC)CCCC SEGLCEQVOFDUPX-UHFFFAOYSA-N 0.000 description 10
- 238000005406 washing Methods 0.000 description 10
- 239000000203 mixture Substances 0.000 description 9
- 238000004519 manufacturing process Methods 0.000 description 8
- 239000002904 solvent Substances 0.000 description 8
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 7
- XLJKHNWPARRRJB-UHFFFAOYSA-N cobalt(2+) Chemical compound [Co+2] XLJKHNWPARRRJB-UHFFFAOYSA-N 0.000 description 7
- 229910052748 manganese Inorganic materials 0.000 description 7
- 239000011572 manganese Substances 0.000 description 7
- 239000002994 raw material Substances 0.000 description 7
- QXZUUHYBWMWJHK-UHFFFAOYSA-N [Co].[Ni] Chemical compound [Co].[Ni] QXZUUHYBWMWJHK-UHFFFAOYSA-N 0.000 description 6
- 229910021645 metal ion Inorganic materials 0.000 description 6
- SOXUFMZTHZXOGC-UHFFFAOYSA-N [Li].[Mn].[Co].[Ni] Chemical compound [Li].[Mn].[Co].[Ni] SOXUFMZTHZXOGC-UHFFFAOYSA-N 0.000 description 5
- 239000002253 acid Substances 0.000 description 5
- 239000000543 intermediate Substances 0.000 description 5
- 239000002893 slag Substances 0.000 description 5
- CSNNHWWHGAXBCP-UHFFFAOYSA-L Magnesium sulfate Chemical compound [Mg+2].[O-][S+2]([O-])([O-])[O-] CSNNHWWHGAXBCP-UHFFFAOYSA-L 0.000 description 4
- ABLZXFCXXLZCGV-UHFFFAOYSA-N Phosphorous acid Chemical compound OP(O)=O ABLZXFCXXLZCGV-UHFFFAOYSA-N 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 125000000740 n-pentyl group Chemical group [H]C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])* 0.000 description 4
- 239000002244 precipitate Substances 0.000 description 4
- 230000008901 benefit Effects 0.000 description 3
- 239000003153 chemical reaction reagent Substances 0.000 description 3
- 229910000361 cobalt sulfate Inorganic materials 0.000 description 3
- 229940044175 cobalt sulfate Drugs 0.000 description 3
- KTVIXTQDYHMGHF-UHFFFAOYSA-L cobalt(2+) sulfate Chemical compound [Co+2].[O-]S([O-])(=O)=O KTVIXTQDYHMGHF-UHFFFAOYSA-L 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 150000002696 manganese Chemical class 0.000 description 3
- LGQLOGILCSXPEA-UHFFFAOYSA-L nickel sulfate Chemical compound [Ni+2].[O-]S([O-])(=O)=O LGQLOGILCSXPEA-UHFFFAOYSA-L 0.000 description 3
- 229910000363 nickel(II) sulfate Inorganic materials 0.000 description 3
- 239000012074 organic phase Substances 0.000 description 3
- 239000002699 waste material Substances 0.000 description 3
- LJKDOMVGKKPJBH-UHFFFAOYSA-N 2-ethylhexyl dihydrogen phosphate Chemical compound CCCCC(CC)COP(O)(O)=O LJKDOMVGKKPJBH-UHFFFAOYSA-N 0.000 description 2
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 238000005238 degreasing Methods 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 229910052943 magnesium sulfate Inorganic materials 0.000 description 2
- 235000019341 magnesium sulphate Nutrition 0.000 description 2
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 238000000746 purification Methods 0.000 description 2
- 238000007670 refining Methods 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 1
- 229910021503 Cobalt(II) hydroxide Inorganic materials 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- 235000011941 Tilia x europaea Nutrition 0.000 description 1
- XTOOSYPCCZOKMC-UHFFFAOYSA-L [OH-].[OH-].[Co].[Ni++] Chemical compound [OH-].[OH-].[Co].[Ni++] XTOOSYPCCZOKMC-UHFFFAOYSA-L 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- BRPQOXSCLDDYGP-UHFFFAOYSA-N calcium oxide Chemical compound [O-2].[Ca+2] BRPQOXSCLDDYGP-UHFFFAOYSA-N 0.000 description 1
- 239000003245 coal Substances 0.000 description 1
- 229910001429 cobalt ion Inorganic materials 0.000 description 1
- -1 cobalt salts Chemical class 0.000 description 1
- INPLXZPZQSLHBR-UHFFFAOYSA-N cobalt(2+);sulfide Chemical compound [S-2].[Co+2] INPLXZPZQSLHBR-UHFFFAOYSA-N 0.000 description 1
- ASKVAEGIVYSGNY-UHFFFAOYSA-L cobalt(ii) hydroxide Chemical compound [OH-].[OH-].[Co+2] ASKVAEGIVYSGNY-UHFFFAOYSA-L 0.000 description 1
- 230000008094 contradictory effect Effects 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 238000009854 hydrometallurgy Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 239000011504 laterite Substances 0.000 description 1
- 229910001710 laterite Inorganic materials 0.000 description 1
- 239000004571 lime Substances 0.000 description 1
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 description 1
- 229910052808 lithium carbonate Inorganic materials 0.000 description 1
- 239000000395 magnesium oxide Substances 0.000 description 1
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 1
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 1
- 238000000197 pyrolysis Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000012216 screening Methods 0.000 description 1
- WWNBZGLDODTKEM-UHFFFAOYSA-N sulfanylidenenickel Chemical compound [Ni]=S WWNBZGLDODTKEM-UHFFFAOYSA-N 0.000 description 1
- 238000005486 sulfidation Methods 0.000 description 1
- 238000004073 vulcanization Methods 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
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- Manufacture And Refinement Of Metals (AREA)
Abstract
The application discloses a method for recycling valuable metals in magnesium-containing wastewater, and belongs to the technical field of metal resource recycling. The method comprises the following steps: mixing the first magnesium-containing wastewater with a first extractant for extraction, and collecting a first raffinate phase; mixing the first raffinate phase with a second extractant to perform multistage extraction, collecting a first extract phase with a first preset stage number, and collecting a second extract phase with a second preset stage number and a lithium salt solution; carrying out multistage back extraction on the second extraction phase, and collecting a first back extraction liquid with a third preset stage number; mixing the first back extraction liquid with a third extractant for extraction, and collecting a second extraction phase and a nickel salt solution; taking the first extraction phase as cobalt solution, and carrying out back extraction on the cobalt solution to obtain cobalt salt solution; and carrying out back extraction on the second extraction phase to obtain a second back extraction liquid, taking the second back extraction liquid as magnesium liquid, and regulating the pH value of the magnesium liquid to obtain a magnesium salt solution. The application at least partially solves the technical problem that the quality of the product recovered from valuable metals in the magnesium-containing wastewater is poor.
Description
Technical Field
The application relates to the technical field of metal resource recycling, in particular to a method for recycling valuable metals in magnesium-containing wastewater.
Background
Magnesium is an important raw material for the modern industry and has a variety of uses. The metallurgical raw materials used in the conventional nickel cobalt manganese lithium hydrometallurgy industry comprise: the waste lithium battery broken powder, the pole piece broken powder, the processed cobalt nickel hydroxide, the waste containing nickel cobalt and the like contain magnesium, and further the magnesium-containing waste water can be produced by utilizing the raw materials to produce nickel cobalt manganese lithium, and the magnesium-containing waste water can also contain valuable metals such as nickel, cobalt and the like.
The recovery of valuable metals from wastewater in conventional technology mostly uses a sulfidation precipitation method. However, for magnesium-containing wastewater, magnesium is easily brought into precipitation slag in the process of generating nickel sulfide and cobalt sulfide precipitation by a vulcanization precipitation method, so that the obtained products are low in purity and poor in quality.
The foregoing is provided merely for the purpose of facilitating understanding of the technical solutions of the present application and is not intended to represent an admission that the foregoing is prior art.
Disclosure of Invention
The application mainly aims to provide a method for recovering valuable metals in magnesium-containing wastewater, which aims to solve the technical problem of poor quality of products recovered from the valuable metals in the conventional magnesium-containing wastewater.
In order to achieve the above purpose, the application provides a method for recovering valuable metals in magnesium-containing wastewater, which comprises the following steps:
Mixing the first magnesium-containing wastewater with a first extractant for extraction, and collecting a first raffinate phase;
Mixing the first raffinate phase with a second extractant for multistage extraction, collecting a first extract phase with a first preset level, and collecting a second extract phase with a second preset level and a lithium salt solution, wherein the first preset level is smaller than the second preset level;
carrying out multistage back extraction on the second extraction phase, and collecting a first back extraction liquid with a third preset stage number;
mixing the first back extraction liquid with a third extractant for extraction, and collecting a second extraction phase and a nickel salt solution;
taking the first extraction phase as cobalt liquid, and carrying out back extraction on the cobalt liquid to obtain cobalt salt solution;
And carrying out back extraction on the second extraction phase to obtain a second back extraction liquid, taking the second back extraction liquid as magnesium liquid, and regulating the pH value of the magnesium liquid to obtain a magnesium salt solution.
Optionally, the method further comprises:
Mixing the second magnesium-containing wastewater with the first extractant for extraction, and collecting a second raffinate phase;
Taking the second raffinate phase as a first solution, mixing the first solution with the second extractant to perform multistage extraction, collecting a third extract phase with a fourth preset level, and collecting a fourth extract phase with a fifth preset level, wherein the fourth preset level is smaller than the fifth preset level;
taking the third extract phase as the cobalt liquid;
and carrying out back extraction on the fourth extraction phase to obtain third extraction liquid, wherein the third extraction liquid is used as the magnesium liquid.
Optionally, after the step of collecting the first strip liquor of the third preset stage number, the method further comprises:
collecting fourth stripping liquid with a sixth preset stage number, wherein the sixth preset stage number is larger than the third preset stage number;
and taking the fourth strip liquor as the first solution.
Optionally, the method further comprises:
the method further comprises the steps of:
Mixing third magnesium-containing wastewater with the first extractant for extraction, and collecting a third raffinate phase;
mixing the third raffinate phase with the second extractant to extract, and collecting a fifth extract phase and a fourth raffinate phase;
Carrying out back extraction on the fifth extraction phase to obtain a fourth back extraction liquid, and taking the fourth back extraction liquid as the first solution;
Mixing the fourth raffinate phase with the third extractant, extracting, and collecting a sixth extract phase and a nickel salt solution;
and carrying out back extraction on the sixth extraction phase to obtain a fifth back extraction liquid, and taking the fifth back extraction liquid as the magnesium liquid.
Optionally, the first magnesium-containing wastewater comprises: black powder leaching liquid;
And/or, the second magnesium-containing wastewater comprises: leaching solution of cobalt intermediate products;
And/or, the third magnesium-containing wastewater comprises: leaching the nickel intermediate product.
Optionally, the first extractant includes: p204;
and/or, the second extractant comprises: p507;
and/or, the third extractant comprises: cyanex272.
Optionally, the volume fraction of the first extractant is 20-30%;
and/or the volume fraction of the second extractant is 20-30%;
And/or the volume fraction of the third extractant is 10-20%.
Optionally, the first extractant is a saponified extractant, and the saponification rate of the first extractant is 30-60%;
and/or the second extractant is a saponified extractant, and the saponification rate of the second extractant is 30-60%;
and/or the third extractant is a saponified extractant, and the saponification rate of the third extractant is 20-50%.
Optionally, the step of adjusting the pH value of the magnesium solution includes:
Adding alkali liquor into the magnesium liquor to adjust the pH value, wherein the alkali liquor comprises the following components: sodium sulfide, sodium carbonate, sodium hydroxide.
Optionally, after the step of collecting the second extraction phase and the lithium salt solution of the second preset number of stages, further comprises:
carrying out lithium precipitation treatment on the lithium salt solution to obtain lithium salt and lithium precipitation mother liquor;
And taking the lithium precipitation mother liquor as the alkali liquor.
The application discloses a recovery method of valuable metals in magnesium-containing wastewater, which comprises the steps of mixing and extracting first magnesium-containing wastewater with a first extractant, and removing impurities in the first magnesium-containing wastewater by utilizing the difference of the extraction capacities of the first extractant on different metals to obtain a first raffinate phase; mixing the first raffinate phase with a second extractant to perform multistage extraction, collecting a first extract phase with a first preset level and rich in cobalt element by utilizing the difference of the second extractant on the extraction capacity of different metals, and collecting a second extract phase with a second preset level and rich in nickel and magnesium and a corresponding raffinate phase (namely lithium salt solution) to realize the recovery of lithium element; performing multistage back extraction on the second extraction phase, and collecting first back extraction liquid with a third preset stage number; mixing the first back extraction liquid with a third extractant for extraction, and collecting a second extraction phase rich in magnesium and a nickel salt solution to realize recovery of nickel element; and then the first extraction phase is used as cobalt liquid, and the cobalt liquid is back extracted to obtain cobalt salt solution, so that recovery of cobalt element is realized; and carrying out back extraction on the second extraction phase to obtain second back extraction liquid, taking the second back extraction liquid as magnesium liquid, regulating the pH value of the magnesium liquid to obtain magnesium salt solution, converting a small amount of nickel and cobalt elements contained in the magnesium liquid into nickel cobalt slag precipitate, and carrying out solid-liquid separation to obtain magnesium salt solution so as to realize recovery of magnesium elements. By utilizing the difference of extraction sequences of different extracting agents on different metal elements, the efficient recovery of lithium, nickel, cobalt and magnesium elements in the first magnesium-containing wastewater is realized, the recovery process is simple, the effective separation of each element can be realized, and the purity and the product quality of the recovered metal product are effectively improved.
Drawings
FIG. 1 is a schematic flow chart of a method for recovering valuable metals in magnesium-containing wastewater according to an embodiment of the application;
FIG. 2 is a process flow diagram of a method for recovering valuable metals in magnesium-containing wastewater according to an embodiment of the application;
FIG. 3 is a graph showing the relationship between P507 metal extraction rate and pH value according to the embodiment of the present application.
The achievement of the objects, functional features and advantages of the present application will be further described with reference to the accompanying drawings, in conjunction with the embodiments.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be clearly and completely described below. 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.
In addition, the meaning of "and/or" as it appears throughout includes three parallel schemes, for example "A and/or B", including the A scheme, or the B scheme, or the scheme where A and B are satisfied simultaneously. In addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be regarded as not exist and not within the protection scope of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.
An embodiment of the present application provides a method for recovering valuable metals from magnesium-containing wastewater, referring to fig. 1 and 2, the method for recovering valuable metals from magnesium-containing wastewater includes:
Step S10, mixing the first magnesium-containing wastewater with a first extractant for extraction, and collecting a first raffinate phase;
In one possible embodiment, impurities in the first magnesium-containing wastewater need to be removed before valuable metal recovery is performed, and then the first magnesium-containing wastewater is mixed with the first extractant, so that the impurities in the first magnesium-containing wastewater enter an organic phase (extract phase) of the first extractant, and a first raffinate phase is collected by separation. The corresponding extract phase contains manganese and other impurities, and manganese salt can be further prepared by using the extract phase after impurity removal.
Optionally, the first magnesium-containing wastewater comprises: black powder leaching solution. The black powder is waste lithium battery black powder or pole piece powder in a lithium battery, namely, black powder containing nickel, cobalt, manganese, copper, iron, aluminum, lithium and other metals and carbon powder, which is obtained through the procedures of disassembly, crushing, screening, pyrolysis, sorting and the like, and the powder is usually used for recycling valuable metals such as nickel, cobalt, manganese, lithium and the like. Illustratively, the black powder is subjected to acid leaching to obtain black powder leaching liquid.
Optionally, the first extractant includes: p204. P204 is di (2-ethylhexyl) phosphoric acid, and the extraction sequence of metal ions is ：Fe3+＞Zn2+＞Ca2+＞Al3+＞Mn2+＞Cu2+＞Co2+＞Ni2+＞Mg2+;, and since the extraction sequence of P204 on nickel and cobalt is later, the separation effect on the two is not ideal. However, P204 has a strong capability of extracting impurity elements such as Zn 2+、Ca2+、Cu2+、Fe3+, and thus P204 is used as impurity removal extraction before nickel-cobalt separation.
Optionally, the volume fraction of the first extractant is 20-30%. The first extractant is a mixture of a pure extractant and solvent oil, wherein the volume fraction of di (2-ethylhexyl) phosphoric acid in the first extractant is 20-30%; for example, 20%, 22%, 24%, 26%, 28%, 30%, etc.
Optionally, the first extractant is a saponified extractant, and the saponification rate of the first extractant is 30-60%, for example, 30%, 35%, 40%, 45%, 50%, 55%, 60%, etc. The first extractant is saponified before being used to stabilize the pH value of the first extractant and enhance the extraction capacity of the first extractant. Since the extraction capacities of the extracting agents for the metals under different pH values are different, the saponification rate of the first extracting agent is determined to be 30-60% in order to ensure the recovery purity of valuable metals in the magnesium-containing wastewater.
Optionally, mixing the first magnesium-containing wastewater with a first extractant, performing 8-12-stage countercurrent extraction, and 8-10-stage countercurrent washing, and collecting a first raffinate phase.
Step S20, mixing the first raffinate phase with a second extractant to perform multistage extraction, collecting a first extract phase with a first preset stage number, and collecting a second extract phase with a second preset stage number and a lithium salt solution, wherein the first preset stage number is smaller than the second preset stage number;
In one possible embodiment, after removing impurities, valuable metals such as lithium, magnesium, nickel, cobalt and the like contained in the first raffinate phase are required to be recovered continuously, the first raffinate phase and the second extractant are mixed for multistage extraction, a first extract phase with a first preset level and rich in cobalt is collected, and a second extract phase with a second preset level and rich in nickel and magnesium and a corresponding raffinate phase (namely lithium salt solution) are collected, wherein the first preset level is smaller than the second preset level.
Optionally, the second extractant includes: p507; p507 refers to 2-ethylhexyl phosphate 2-ethylhexyl ester, and referring to fig. 3, the metal ion extraction sequence is: fe 3+＞Zn2+＞Cu2+≈Mn2+≈Ca2+＞Co2+＞Mg2+＞Ni2+, wherein the extraction curves of nickel and cobalt are far apart, so that the separation coefficient of P507 to cobalt and nickel is higher than that of P204, and the method can be used for separating cobalt and nickel.
Optionally, the volume fraction of the second extractant is 20-30%; the second extractant is a mixture of a pure extractant and solvent oil, wherein the volume fraction of 2-ethylhexyl phosphate 2-ethylhexyl ester in the second extractant is 20-30%; for example, 20%, 22%, 24%, 26%, 28%, 30%, etc.
Optionally, the second extractant is a saponified extractant, and the saponification rate of the second extractant is 30-60%; for example, 30%, 35%, 40%, 45%, 50%, 55%, 60%, etc. The second extractant is saponified before being used to stabilize the pH value of the second extractant and enhance the extraction capacity of the second extractant. Since the extractant has different extraction capacities for each metal under different pH values, the saponification rate of the second extractant is determined to be 30-60% in order to ensure the recovery purity of valuable metals in the magnesium-containing wastewater.
Optionally, evaporating and crystallizing the lithium salt solution to obtain lithium salt.
Alternatively, the number of stages of the multistage extraction may be 16-24 stages.
In a possible embodiment, after the step of collecting the second extraction phase and the lithium salt solution of the second preset number of stages in step S20, it further comprises:
step S23, carrying out lithium precipitation treatment on the lithium salt solution to obtain lithium salt and lithium precipitation mother liquor;
and step S24, taking the lithium precipitation mother liquor as the alkali liquor.
In a possible embodiment, adding soluble carbonate into the lithium salt solution to perform lithium precipitation treatment to obtain lithium salt and lithium precipitation mother liquor; the lithium precipitation mother liquor contains a large amount of carbonate which does not react completely, such as sodium carbonate; conventionally, the lithium precipitation mother liquor is used as alkali liquor for regulating the pH value of the magnesium liquor to realize the recycling of resources.
Step S30, carrying out multistage back extraction on the second extraction phase, and collecting a first back extraction liquid with a third preset stage number;
In one possible embodiment, the second extract phase rich in nickel and magnesium is subjected to multistage stripping, and the first stripping liquid rich in nickel of a third preset stage is collected.
Alternatively, the stripping agent may be sulfuric acid.
In one possible embodiment, after the step of collecting the first strip liquor of the third preset stage number in step S30, the method further includes:
Step S31, collecting fourth stripping liquid with a sixth preset stage number, wherein the sixth preset stage number is larger than the third preset stage number;
In one possible embodiment, when the second extraction phase is stripped, since the second extraction phase contains cobalt, magnesium and nickel, and the nickel is stripped preferentially, a first stripping solution is obtained, and the stripping is further carried out until a sixth preset level, so as to obtain a fourth stripping solution rich in cobalt and magnesium.
Although the second extractant can be used for realizing complete extraction and separation of cobalt and magnesium in actual production, the saponification rate of the second extractant needs to be improved, namely the flow of liquid alkali needs to be increased, at the moment, part of nickel is extracted, a large amount of acid is needed to be washed down later, and auxiliary materials are consumed, so that the application uses the second extractant with the saponification rate of 30-60%, and synchronously extracted cobalt and magnesium are introduced into a production line of second magnesium-containing wastewater during extraction, thereby realizing further extraction.
And step S32, taking the fourth strip liquor as the first solution.
In a possible embodiment, since the fourth strip liquor contains cobalt and magnesium, in order to improve the purity of the product, reduce the process equipment and the process cost, the fourth strip liquor is used as the first solution, so that the fourth strip liquor is extracted together with the second raffinate phase obtained based on the second magnesium-containing wastewater, and the recovery processes of different magnesium-containing wastewater can be combined with each other, so that the treatment efficiency and the process cost are improved, and the cost and the efficiency are reduced.
Step S40, mixing the first strip liquor with a third extractant for extraction, and collecting a second extraction phase and a nickel salt solution;
In one possible embodiment, a portion of magnesium may also be present in the nickel-rich first strip liquor, which is mixed with a third extractant to extract in order to increase the purity of the product, and the second extract phase and the corresponding raffinate phase (i.e., nickel salt solution) are collected.
Optionally, the third extractant includes: cyanex272; the main component of Cyanex272 is di (2, 4-trimethyl amyl) phosphonic acid; under the same conditions, the separation coefficient of the Cyanex272 to nickel and cobalt is higher than that of P507 by an order of magnitude, wherein the cis- ：Fe3+>Zn2+>Cu2+>Mn2+>Co2+>Mg2+>Ca2+>Ni2+. of the Cyanex272 to metal ion extraction preferentially extracts magnesium under the same extraction conditions, so that nickel and magnesium can be separated efficiently, but meanwhile, compared with P204 and P507, the Cyanex272 has higher cost, so that the Cyanex272 is reused when valuable metals of magnesium-containing wastewater are recycled, and the process cost is effectively reduced on the basis of ensuring the purity of products.
Optionally, the volume fraction of the third extractant is 10-20%. The third extractant is a mixture of a pure extractant and solvent oil, wherein the volume fraction of the di (2, 4-trimethyl amyl) phosphonic acid in the third extractant is 10-20%; for example, 10%, 12%, 14%, 16%, 18%, 20%, etc.
Optionally, the third extractant is a saponified extractant, and the saponification rate of the third extractant is 20-50%. For example, 20%, 25%, 30%, 35%, 40%, 45%, 50%, etc. The third extractant is saponified before being used to stabilize the pH value of the third extractant and enhance the extraction capacity of the third extractant. Since the extraction capacities of the extracting agents for the metals under different pH values are different, the saponification rate of the third extracting agent is determined to be 20-50% in order to ensure the recovery purity of valuable metals in the magnesium-containing wastewater.
Optionally, the resulting nickel salt solution is subjected to degreasing, refining, etc., to obtain a battery grade nickel salt, e.g., battery grade nickel sulfate.
Optionally, the third extractant is mixed with the first stripping solution after 4-6-level countercurrent soap-washing, 8-10-level countercurrent extraction and 4-8-level countercurrent washing are carried out, and the second extract phase and the nickel salt solution are collected. And carrying out back extraction on the second extraction phase to obtain second back extraction liquid, and taking the second back extraction liquid as magnesium liquid.
Step S50, taking the first extraction phase as cobalt liquid, and carrying out back extraction on the cobalt liquid to obtain cobalt salt solution;
in one possible embodiment, the first extraction phase is rich in cobalt, and the first extraction phase is used as cobalt solution, and the cobalt solution is further back extracted to obtain cobalt salt solution.
Alternatively, sulfuric acid may be used for stripping.
Optionally, the resulting cobalt salt solution is subjected to degreasing, refining, etc., to obtain a battery grade cobalt salt, e.g., battery grade cobalt sulfate.
And step S60, carrying out back extraction on the second extraction phase to obtain second back extraction liquid, taking the second back extraction liquid as magnesium liquid, and regulating the pH value of the magnesium liquid to obtain magnesium salt solution.
In a possible embodiment, the second extraction phase rich in magnesium is back-extracted to obtain a second back-extracted solution; and the second stripping liquid is used as magnesium liquid, and the pH value of the magnesium liquid is regulated so as to convert a small amount of nickel and cobalt elements contained in the magnesium liquid into nickel and cobalt slag precipitate, and a magnesium salt solution is obtained after solid-liquid separation, thereby realizing the recovery of the magnesium elements.
Alternatively, sulfuric acid may be used for stripping.
In a possible embodiment, step S60, the step of adjusting the pH value of the magnesium solution includes:
step S61, adding alkali liquor into the magnesium liquor to adjust the pH value, wherein the alkali liquor comprises the following components: sodium sulfide, sodium carbonate, sodium hydroxide.
In a possible embodiment, adding alkali liquor into the magnesium liquor to adjust the pH value of the magnesium liquor so as to convert a small amount of nickel and cobalt elements contained in the magnesium liquor into nickel and cobalt slag precipitates, and obtaining magnesium salt solution after solid-liquid separation to realize recovery of magnesium elements; wherein, alkali lye includes: sodium sulfide, sodium carbonate, sodium hydroxide.
In the embodiment, the first magnesium-containing wastewater is mixed with a first extractant for extraction, and impurities in the first magnesium-containing wastewater are removed by utilizing the difference of the extraction capacities of the first extractant on different metals to obtain a first raffinate phase; mixing the first raffinate phase with a second extractant to perform multistage extraction, collecting a first extract phase with a first preset level and rich in cobalt element by utilizing the difference of the second extractant on the extraction capacity of different metals, and collecting a second extract phase with a second preset level and rich in nickel and magnesium and a corresponding raffinate phase (namely lithium salt solution) to realize the recovery of lithium element; performing multistage back extraction on the second extraction phase, and collecting first back extraction liquid with a third preset stage number; mixing the first back extraction liquid with a third extractant for extraction, and collecting a second extraction phase rich in magnesium and a nickel salt solution to realize recovery of nickel element; and then the first extraction phase is used as cobalt liquid, and the cobalt liquid is back extracted to obtain cobalt salt solution, so that recovery of cobalt element is realized; and carrying out back extraction on the second extraction phase to obtain second back extraction liquid, taking the second back extraction liquid as magnesium liquid, regulating the pH value of the magnesium liquid to obtain magnesium salt solution, converting a small amount of nickel and cobalt elements contained in the magnesium liquid into nickel cobalt slag precipitate, and carrying out solid-liquid separation to obtain magnesium salt solution so as to realize recovery of magnesium elements. By utilizing the difference of extraction sequences of different extracting agents on different metal elements, the efficient recovery of lithium, nickel, cobalt and magnesium elements in the first magnesium-containing wastewater is realized, the recovery process is simple, the effective separation of each element can be realized, and the purity and the product quality of the recovered metal product are effectively improved.
Further, based on the first embodiment, a second embodiment of the method for recovering valuable metals in magnesium-containing wastewater is provided, and in this embodiment, the method further includes:
Step A10, mixing second magnesium-containing wastewater with the first extractant for extraction, and collecting a second raffinate phase;
In one possible embodiment, the purification of nickel cobalt manganese lithium materials from different raw materials can produce similar but somewhat different magnesium-containing wastewater, including a second magnesium-containing wastewater in addition to the first magnesium-containing wastewater; removing impurities from the second magnesium-containing wastewater before valuable metal recovery is carried out on the second magnesium-containing wastewater; and mixing the second magnesium-containing wastewater with the first extractant to enable impurities in the second magnesium-containing wastewater to enter an organic phase (extract phase) of the first extractant, and collecting a second raffinate phase through separation. The corresponding extract phase contains manganese and other impurities, and manganese salt can be further prepared by using the extract phase after impurity removal.
Optionally, the second magnesium-containing wastewater comprises: leaching solution of cobalt intermediate product. Cobalt intermediates are raw materials for making cobalt-series compounds, i.e., cobalt ion-containing compounds, including cobalt salts, crude cobalt hydroxide, and the like. Illustratively, acid leaching is performed on the cobalt intermediate product to obtain a cobalt intermediate product leaching solution.
Optionally, the first extractant includes: p204. P204 is di (2-ethylhexyl) phosphoric acid, and the extraction sequence of metal ions is ：Fe3+＞Zn2+＞Ca2+＞Al3+＞Mn2+＞Cu2+＞Co2+＞Ni2+＞Mg2+;, and since the extraction sequence of P204 on nickel and cobalt is later, the separation effect on the two is not ideal. However, P204 has a strong capability of extracting impurity elements such as Zn 2+、Ca2+、Cu2+、Fe3+, and thus P204 is used as impurity removal extraction before nickel-cobalt separation.
Optionally, the volume fraction of the first extractant is 20-30%. The first extractant is a mixture of a pure extractant and solvent oil, wherein the volume fraction of di (2-ethylhexyl) phosphoric acid in the first extractant is 20-30%; for example, 20%, 22%, 24%, 26%, 28%, 30%, etc.
Optionally, the first extractant is a saponified extractant, and the saponification rate of the first extractant is 30-60%, for example, 30%, 35%, 40%, 45%, 50%, 55%, 60%, etc. The first extractant is saponified before being used to stabilize the pH value of the first extractant and enhance the extraction capacity of the first extractant. Since the extraction capacities of the extracting agents for the metals under different pH values are different, the saponification rate of the first extracting agent is determined to be 30-60% in order to ensure the recovery purity of valuable metals in the magnesium-containing wastewater.
Optionally, mixing the second magnesium-containing wastewater with the first extractant, performing 8-12-stage countercurrent extraction, and 8-10-stage countercurrent washing, and collecting a second raffinate phase.
Step A20, taking the second raffinate phase as a first solution, mixing the first solution with the second extractant to perform multistage extraction, collecting a third extract phase with a fourth preset level, and collecting a fourth extract phase with a fifth preset level, wherein the fourth preset level is smaller than the fifth preset level;
In one possible embodiment, the second raffinate phase is used as the first solution, and since the first solution contains cobalt, magnesium and nickel, it is necessary to separate the metals by multistage extraction; and mixing the first solution with the second extractant to perform multistage extraction, collecting a third extract phase rich in cobalt and having a fourth preset level, and collecting a fourth extract phase rich in magnesium and having a fifth preset level.
Optionally, the second extractant includes: p507; p507 is 2-ethylhexyl phosphate, which can be used for separating cobalt and magnesium.
Optionally, the volume fraction of the second extractant is 20-30%; the second extractant is a mixture of a pure extractant and solvent oil, wherein the volume fraction of 2-ethylhexyl phosphate 2-ethylhexyl ester in the second extractant is 20-30%; for example, 20%, 22%, 24%, 26%, 28%, 30%, etc.
Optionally, the second extractant is a saponified extractant, and the saponification rate of the second extractant is 30-60%; for example, 30%, 35%, 40%, 45%, 50%, 55%, 60%, etc. The second extractant is saponified before being used to stabilize the pH value of the second extractant and enhance the extraction capacity of the second extractant. Since the extractant has different extraction capacities for each metal under different pH values, the saponification rate of the second extractant is determined to be 30-60% in order to ensure the recovery purity of valuable metals in the magnesium-containing wastewater.
Alternatively, the number of stages of the multistage extraction may be 16-24 stages.
Step A30, taking the third extract phase as the cobalt liquid;
In a possible embodiment, the third extraction phase is used as cobalt liquid, so that the cobalt is back-extracted together with the first extraction phase obtained based on the first coal-containing wastewater, and the efficient combination of different recovery production lines is realized.
And step A40, carrying out back extraction on the fourth extraction phase to obtain a third extraction liquid, and taking the third extraction liquid as the magnesium liquid.
In a possible embodiment, the fourth extraction phase rich in magnesium is back-extracted to obtain a third extraction liquid, and the third extraction liquid is further used as a magnesium liquid together with the second back-extraction liquid obtained based on the first magnesium-containing wastewater because the third extraction liquid is rich in magnesium, so that efficient recovery of magnesium is realized.
In the embodiment, the efficient recovery of valuable metals in the second magnesium-containing wastewater is realized by using the same reagent (extractant, back extractant and the like) as the first magnesium-containing wastewater, and meanwhile, the recovery production lines of the first magnesium-containing wastewater and the second magnesium-containing wastewater are skillfully combined together, so that the recovery efficiency is improved, the production cost is effectively reduced, and the cost and the synergy are realized.
Further, based on the first and/or second embodiment, a third embodiment of a method for recovering valuable metals in magnesium-containing wastewater according to the present application is provided, and in this embodiment, the method further includes:
step B10, mixing third magnesium-containing wastewater with the first extractant for extraction, and collecting a third raffinate phase;
In a possible embodiment, the purification of nickel cobalt manganese lithium materials from different raw materials can produce similar but somewhat different magnesium-containing wastewater, and include a third magnesium-containing wastewater in addition to the first magnesium-containing wastewater and the second magnesium-containing wastewater; removing impurities from the third magnesium-containing wastewater before valuable metal recovery is carried out on the third magnesium-containing wastewater; and mixing the third magnesium-containing wastewater with the first extractant, allowing impurities in the third magnesium-containing wastewater to enter an organic phase (extract phase) of the first extractant, and collecting a third raffinate phase through separation. The corresponding extract phase contains manganese and other impurities, and manganese salt can be further prepared by using the extract phase after impurity removal.
Optionally, the first magnesium-containing wastewater, the second magnesium-containing wastewater and the third magnesium-containing wastewater are magnesium-containing wastewater generated by purifying and producing nickel cobalt manganese lithium materials by different raw materials, and the elements of the first magnesium-containing wastewater, the second magnesium-containing wastewater and the third magnesium-containing wastewater have similar compositions but have slight differences; therefore, the process production line for recovering valuable metals of the three magnesium-containing wastewater is combined, so that the setting of process equipment can be reduced, the overall process cost is reduced, and the cost and efficiency are reduced on the basis of ensuring the purity of the product.
Optionally, the third magnesium-containing wastewater comprises: leaching the nickel intermediate product. The nickel intermediate is prepared by adopting liquid alkali, lime and magnesium oxide precipitation after pressurizing or normal pressure acid leaching of laterite nickel ore, and the main component is alkali sulfate of nickel, cobalt and manganese. Illustratively, acid leaching is performed on the nickel intermediate product to obtain a nickel intermediate product leaching solution.
Optionally, the first extractant includes: p204. P204 is di (2-ethylhexyl) phosphoric acid, and the extraction sequence of metal ions is ：Fe3+＞Zn2+＞Ca2+＞Al3+＞Mn2+＞Cu2+＞Co2+＞Ni2+＞Mg2+;, and since the extraction sequence of P204 on nickel and cobalt is later, the separation effect on the two is not ideal. However, P204 has a strong capability of extracting impurity elements such as Zn 2+、Ca2+、Cu2+、Fe3+, and thus P204 is used as impurity removal extraction before nickel-cobalt separation.
Optionally, the volume fraction of the first extractant is 20-30%. The first extractant is a mixture of a pure extractant and solvent oil, wherein the volume fraction of di (2-ethylhexyl) phosphoric acid in the first extractant is 20-30%; for example, 20%, 22%, 24%, 26%, 28%, 30%, etc.
Optionally, the first extractant is a saponified extractant, and the saponification rate of the first extractant is 30-60%, for example, 30%, 35%, 40%, 45%, 50%, 55%, 60%, etc. The first extractant is saponified before being used to stabilize the pH value of the first extractant and enhance the extraction capacity of the first extractant. Since the extraction capacities of the extracting agents for the metals under different pH values are different, the saponification rate of the first extracting agent is determined to be 30-60% in order to ensure the recovery purity of valuable metals in the magnesium-containing wastewater.
Optionally, the first extractant is mixed with the third magnesium-containing wastewater after 4-6-level countercurrent soap-washing, 8-12-level countercurrent extraction and 8-10-level countercurrent washing are carried out, and a third raffinate phase is collected.
Step B20, mixing the third raffinate phase with the second extractant for extraction, and collecting a fifth extract phase and a fourth raffinate phase;
In one possible embodiment, the third raffinate phase is mixed with the second extractant for fine extraction, and the fifth extract phase and the fourth raffinate phase which are rich in cobalt and magnesium are collected.
Optionally, the second extractant includes: p507; p507 is 2-ethylhexyl phosphate, which can be used for separating cobalt and magnesium.
Optionally, the volume fraction of the second extractant is 20-30%; the second extractant is a mixture of a pure extractant and solvent oil, wherein the volume fraction of 2-ethylhexyl phosphate 2-ethylhexyl ester in the second extractant is 20-30%; for example, 20%, 22%, 24%, 26%, 28%, 30%, etc.
Optionally, the second extractant is a saponified extractant, and the saponification rate of the second extractant is 30-60%; for example, 30%, 35%, 40%, 45%, 50%, 55%, 60%, etc. The second extractant is saponified before being used to stabilize the pH value of the second extractant and enhance the extraction capacity of the second extractant. Since the extractant has different extraction capacities for each metal under different pH values, the saponification rate of the second extractant is determined to be 30-60% in order to ensure the recovery purity of valuable metals in the magnesium-containing wastewater.
Optionally, the second extractant is mixed with the third raffinate phase after 4-6-level countercurrent soap-washing, 8-12-level countercurrent extraction and 8-10-level countercurrent washing, and the fifth extract phase and the fourth raffinate phase are collected.
Step B30, carrying out back extraction on the fifth extraction phase to obtain a fourth back extraction liquid, and taking the fourth back extraction liquid as the first solution;
In a possible embodiment, the fifth extract phase rich in cobalt and magnesium is back extracted to obtain a fourth back extract solution, and in order to further separate cobalt and magnesium in the fourth back extract solution, the fourth back extract solution is used as a first solution, so as to be extracted and separated together with a second raffinate phase generated based on the second magnesium-containing wastewater.
Step B40, mixing the fourth raffinate phase with the third extractant, extracting, and collecting a sixth extract phase and a nickel salt solution;
In one possible embodiment, the fourth raffinate phase is mixed with a third extractant for extraction, and then the magnesium-rich sixth extract phase and the corresponding raffinate phase (i.e., nickel salt solution) are collected.
Optionally, the third extractant includes: cyanex272; the main component of Cyanex272 is di (2, 4-trimethyl amyl) phosphonic acid; under the same conditions, the separation coefficient of the Cyanex272 to nickel and cobalt is higher than that of P507 by an order of magnitude, wherein the cis- ：Fe3+>Zn2+>Cu2+>Mn2+>Co2+>Mg2+>Ca2+>Ni2+. of the Cyanex272 to metal ion extraction preferentially extracts magnesium under the same extraction conditions, so that nickel and magnesium can be separated efficiently, but meanwhile, compared with P204 and P507, the Cyanex272 has higher cost, so that the Cyanex272 is reused when valuable metals of magnesium-containing wastewater are recycled, and the process cost is effectively reduced on the basis of ensuring the purity of products.
Optionally, the volume fraction of the third extractant is 10-20%. The third extractant is a mixture of a pure extractant and solvent oil, wherein the volume fraction of the di (2, 4-trimethyl amyl) phosphonic acid in the third extractant is 10-20%; for example, 10%, 12%, 14%, 16%, 18%, 20%, etc.
Optionally, the third extractant is a saponified extractant, and the saponification rate of the third extractant is 20-50%. For example, 20%, 25%, 30%, 35%, 40%, 45%, 50%, etc. The third extractant is saponified before being used to stabilize the pH value of the third extractant and enhance the extraction capacity of the third extractant. Since the extraction capacities of the extracting agents for the metals under different pH values are different, the saponification rate of the third extracting agent is determined to be 20-50% in order to ensure the recovery purity of valuable metals in the magnesium-containing wastewater.
Optionally, the third extractant is mixed with the fourth raffinate phase after 4-6-level countercurrent soap-washing, 8-10-level countercurrent extraction and 4-8-level countercurrent washing, and the sixth extract phase and nickel salt solution are collected.
And step B50, carrying out back extraction on the sixth extraction phase to obtain a fifth back extraction liquid, and taking the fifth back extraction liquid as the magnesium liquid.
In a possible embodiment, the sixth extraction phase is back extracted to obtain a fifth back extraction solution, and the fifth back extraction solution is used as magnesium solution, so that the fifth back extraction solution and the magnesium solution obtained based on other magnesium-containing wastewater are treated together, and efficient recovery of magnesium is realized.
Alternatively, sulfuric acid may be used for stripping.
In the embodiment, the efficient recovery of valuable metals in the third magnesium-containing wastewater is realized by using the same reagents (extraction agent, stripping agent and the like) as the first magnesium-containing wastewater and the first magnesium-containing wastewater, and meanwhile, the recovery production lines of the first magnesium-containing wastewater, the second magnesium-containing wastewater and the third magnesium-containing wastewater are skillfully combined together, so that the recovery efficiency is improved, the production cost is effectively reduced, and the cost reduction and synergy are realized.
In order that the details and operation of the above embodiments of the present application may be clearly understood by those skilled in the art, and that the improvement performance of the recovery method of valuable metals in magnesium-containing wastewater according to the embodiments of the present application may be significantly embodied, the above technical solutions are exemplified by the following examples.
Example 1
1) Obtaining black powder leaching liquid to be used as first magnesium-containing wastewater, wherein the black powder leaching liquid comprises the following components: cobalt content 19.27g/L, nickel content 48.89g/L, manganese content 23.06g/L, lithium content 8.04g/L, and magnesium content 0.38g/L;
2) Mixing the first magnesium-containing wastewater with P204 for 10-level extraction, and collecting a first raffinate phase; wherein the volume fraction of P204 is 25%, and the saponification rate is 50%;
3) Mixing the first raffinate phase with P507 for multistage extraction, collecting the first extract phase of 12 th stage, and collecting the second extract phase of 24 th stage and lithium salt solution, wherein the volume fraction of P507 is 25%, and the saponification rate is 60%;
4) Carrying out multistage back extraction on the second extraction phase by using sulfuric acid, collecting 12 th-stage first back extraction liquid and 24 th-stage fourth back extraction liquid, mixing the first back extraction liquid with Cyanex272 for 6-stage extraction, and collecting the second extraction phase and nickel sulfate solution, wherein the volume fraction of Cyanex272 is 15%, and the saponification rate is 50%;
5) The fourth strip liquor is taken as the first solution to enter a treatment section of the second magnesium-containing wastewater in the embodiment 2 for treatment;
6) Taking the first extraction phase as cobalt liquid, and carrying out 12-stage back extraction on the cobalt liquid by using sulfuric acid to obtain a cobalt sulfate solution;
7) Carrying out 12-level back extraction on the second extraction phase by using sulfuric acid to obtain second back extraction liquid, taking the second back extraction liquid as magnesium liquid, regulating the pH value of the magnesium liquid, and carrying out solid-liquid separation to obtain magnesium sulfate solution;
Example 2
1) Obtaining cobalt intermediate leaching liquid as second magnesium-containing wastewater, wherein the cobalt intermediate leaching liquid comprises the following components: 63.05g/L cobalt, 1.39g/L nickel, 8.19g/L manganese and 9.16g/L magnesium;
2) Mixing the second magnesium-containing wastewater with P204 for 12-level extraction, and collecting a second raffinate phase, wherein the volume fraction of P204 is 25%, and the saponification rate is 50%;
3) Taking the second raffinate phase as a first solution, mixing the first solution with P507 for multistage extraction, collecting a third extract phase of a 12 th stage, and collecting a fourth extract phase of a 24 th stage, wherein the volume fraction of P507 is 25%, and the saponification rate is 60%;
4) Taking the third extraction phase as cobalt liquid, and introducing the cobalt liquid into a treatment section of the first magnesium-containing wastewater in the embodiment 1 for treatment;
5) The fourth extract phase is subjected to 12-stage back extraction by sulfuric acid to obtain a third extract liquid, and the third extract liquid is taken as magnesium liquid to enter a treatment section of the first magnesium-containing wastewater of the embodiment 1 for treatment.
Example 3
1) Obtaining a nickel intermediate leaching solution as third magnesium-containing wastewater, wherein the third magnesium-containing wastewater comprises the following components: cobalt content 5.39g/L, nickel content 69.22g/L, manganese content 4.48g/L, and magnesium content 5.48g/L;
2) Mixing the third magnesium-containing wastewater with P204 for 12-level extraction, and collecting a third raffinate phase, wherein the volume fraction of P204 is 25%, and the saponification rate is 50%;
3) Mixing the third raffinate phase with P507 for 12-level extraction, and collecting a fifth extract phase and a fourth raffinate phase;
4) Carrying out 12-stage back extraction on the fifth extraction phase by using sulfuric acid to obtain fourth back extraction liquid, and taking the fourth back extraction liquid as a first solution to enter a treatment section of the second magnesium-containing wastewater in the embodiment 2 for treatment;
5) Mixing the fourth raffinate phase with Cyanex272 and performing 8-stage extraction, and collecting a sixth extract phase and nickel salt solution, wherein the Cyanex272 has a volume fraction of 15% and a saponification rate of 50%;
6) And carrying out 12-stage back extraction on the sixth extraction phase by using sulfuric acid to obtain a fifth back extraction liquid, and taking the fifth back extraction liquid as magnesium liquid to enter a treatment section of the first magnesium-containing wastewater of the embodiment 1 for treatment.
Through the steps, the recovery rate of nickel is 98.62%, the recovery rate of magnesium is 97.31%, the recovery rate of cobalt is 96.33%, and the recovery rate of lithium is 96.28%; the purity of nickel sulfate in the obtained product is more than 99%, the purity of magnesium sulfate is more than 99%, the purity of cobalt sulfate is more than 99%, and the purity of lithium carbonate is more than 99%. According to the embodiment 1-3, the recovery method of valuable metals in the magnesium-containing wastewater can effectively separate the valuable metals, improve the purity of the product and realize efficient recovery; and the recovery process is simple, the process cost is low, and the economic benefit is good.
The foregoing is merely a preferred embodiment of the present application and is not intended to limit the scope of the present application, but various modifications and variations will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the present application.
Claims (10)
1. The method for recovering valuable metals in the magnesium-containing wastewater is characterized by comprising the following steps of:
Mixing the first magnesium-containing wastewater with a first extractant for extraction, and collecting a first raffinate phase;
Mixing the first raffinate phase with a second extractant for multistage extraction, collecting a first extract phase with a first preset level, and collecting a second extract phase with a second preset level and a lithium salt solution, wherein the first preset level is smaller than the second preset level;
carrying out multistage back extraction on the second extraction phase, and collecting a first back extraction liquid with a third preset stage number;
mixing the first back extraction liquid with a third extractant for extraction, and collecting a second extraction phase and a nickel salt solution;
taking the first extraction phase as cobalt liquid, and carrying out back extraction on the cobalt liquid to obtain cobalt salt solution;
And carrying out back extraction on the second extraction phase to obtain a second back extraction liquid, taking the second back extraction liquid as magnesium liquid, and regulating the pH value of the magnesium liquid to obtain a magnesium salt solution.
2. The method for recovering valuable metals from magnesium containing waste water as claimed in claim 1, wherein said method further comprises:
Mixing the second magnesium-containing wastewater with the first extractant for extraction, and collecting a second raffinate phase;
Taking the second raffinate phase as a first solution, mixing the first solution with the second extractant to perform multistage extraction, collecting a third extract phase with a fourth preset level, and collecting a fourth extract phase with a fifth preset level, wherein the fourth preset level is smaller than the fifth preset level;
taking the third extract phase as the cobalt liquid;
and carrying out back extraction on the fourth extraction phase to obtain third extraction liquid, wherein the third extraction liquid is used as the magnesium liquid.
3. The method for recovering valuable metals from magnesium containing wastewater as claimed in claim 2, further comprising, after said step of collecting the first strip liquor of a third predetermined level:
collecting fourth stripping liquid with a sixth preset stage number, wherein the sixth preset stage number is larger than the third preset stage number;
and taking the fourth strip liquor as the first solution.
4. The method for recovering valuable metals from magnesium-containing wastewater as claimed in claim 2, wherein the method further comprises:
Mixing third magnesium-containing wastewater with the first extractant for extraction, and collecting a third raffinate phase;
mixing the third raffinate phase with the second extractant to extract, and collecting a fifth extract phase and a fourth raffinate phase;
Carrying out back extraction on the fifth extraction phase to obtain a fourth back extraction liquid, and taking the fourth back extraction liquid as the first solution;
Mixing the fourth raffinate phase with the third extractant, extracting, and collecting a sixth extract phase and a nickel salt solution;
and carrying out back extraction on the sixth extraction phase to obtain a fifth back extraction liquid, and taking the fifth back extraction liquid as the magnesium liquid.
5. The method for recovering valuable metals from magnesium containing waste water as claimed in claim 4, wherein said first magnesium containing waste water comprises: black powder leaching liquid;
And/or, the second magnesium-containing wastewater comprises: leaching solution of cobalt intermediate products;
And/or, the third magnesium-containing wastewater comprises: leaching the nickel intermediate product.
6. The method for recovering valuable metals in magnesium containing wastewater according to any one of claims 1 to 4, wherein the first extractant comprises: p204;
and/or, the second extractant comprises: p507;
and/or, the third extractant comprises: cyanex272.
7. The method for recovering valuable metals in magnesium-containing wastewater according to any one of claims 1 to 4, wherein the volume fraction of the first extractant is 20 to 30%;
and/or the volume fraction of the second extractant is 20-30%;
And/or the volume fraction of the third extractant is 10-20%.
8. The method for recovering valuable metals in magnesium-containing wastewater according to any one of claims 1 to 4, wherein the first extractant is a saponified extractant, and the saponification rate of the first extractant is 30 to 60%;
and/or the second extractant is a saponified extractant, and the saponification rate of the second extractant is 30-60%;
and/or the third extractant is a saponified extractant, and the saponification rate of the third extractant is 20-50%.
9. The method for recovering valuable metals in magnesium-containing wastewater according to any one of claims 1 to 4, wherein the step of adjusting the pH value of the magnesium solution comprises:
Adding alkali liquor into the magnesium liquor to adjust the pH value, wherein the alkali liquor comprises the following components: sodium sulfide, sodium carbonate, sodium hydroxide.
10. The method for recovering valuable metals from magnesium containing wastewater of claim 9, further comprising, after said step of collecting a second extraction phase and a lithium salt solution of a second predetermined number of stages:
carrying out lithium precipitation treatment on the lithium salt solution to obtain lithium salt and lithium precipitation mother liquor;
And taking the lithium precipitation mother liquor as the alkali liquor.
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| CN202410193658.2A CN118086678A (en) | 2024-02-21 | 2024-02-21 | Method for recovering valuable metals in magnesium-containing wastewater |
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