CN117263178A - Method for preparing high-quality graphite by catalytic graphitization of waste cathode carbon - Google Patents
Method for preparing high-quality graphite by catalytic graphitization of waste cathode carbon Download PDFInfo
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- CN117263178A CN117263178A CN202311272454.XA CN202311272454A CN117263178A CN 117263178 A CN117263178 A CN 117263178A CN 202311272454 A CN202311272454 A CN 202311272454A CN 117263178 A CN117263178 A CN 117263178A
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- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 title claims abstract description 161
- 239000002699 waste material Substances 0.000 title claims abstract description 80
- 238000005087 graphitization Methods 0.000 title claims abstract description 71
- 229910052799 carbon Inorganic materials 0.000 title claims abstract description 70
- 229910002804 graphite Inorganic materials 0.000 title claims abstract description 62
- 239000010439 graphite Substances 0.000 title claims abstract description 62
- 238000000034 method Methods 0.000 title claims abstract description 44
- 230000003197 catalytic effect Effects 0.000 title claims abstract description 43
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims abstract description 62
- 239000003054 catalyst Substances 0.000 claims abstract description 36
- 238000002386 leaching Methods 0.000 claims abstract description 36
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 28
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims abstract description 28
- 238000005868 electrolysis reaction Methods 0.000 claims abstract description 25
- 238000005554 pickling Methods 0.000 claims abstract description 21
- 239000002253 acid Substances 0.000 claims abstract description 20
- 238000001704 evaporation Methods 0.000 claims abstract description 18
- 230000008020 evaporation Effects 0.000 claims abstract description 18
- 238000007885 magnetic separation Methods 0.000 claims abstract description 18
- 229910052751 metal Inorganic materials 0.000 claims abstract description 18
- 239000002184 metal Substances 0.000 claims abstract description 18
- 238000002156 mixing Methods 0.000 claims abstract description 12
- 239000013078 crystal Substances 0.000 claims abstract description 11
- 238000004064 recycling Methods 0.000 claims abstract description 7
- 238000001914 filtration Methods 0.000 claims abstract description 5
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 52
- 239000000243 solution Substances 0.000 claims description 36
- 238000005406 washing Methods 0.000 claims description 21
- 229910052593 corundum Inorganic materials 0.000 claims description 13
- 239000010431 corundum Substances 0.000 claims description 13
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 12
- 238000006243 chemical reaction Methods 0.000 claims description 12
- 239000000203 mixture Substances 0.000 claims description 12
- 239000006249 magnetic particle Substances 0.000 claims description 11
- 230000008569 process Effects 0.000 claims description 10
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 9
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 9
- 239000012670 alkaline solution Substances 0.000 claims description 9
- 238000012216 screening Methods 0.000 claims description 9
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 claims description 8
- 239000012298 atmosphere Substances 0.000 claims description 8
- 239000002245 particle Substances 0.000 claims description 8
- 239000000843 powder Substances 0.000 claims description 8
- 238000011049 filling Methods 0.000 claims description 7
- 238000000227 grinding Methods 0.000 claims description 7
- 238000000967 suction filtration Methods 0.000 claims description 7
- 239000007787 solid Substances 0.000 claims description 6
- 239000012300 argon atmosphere Substances 0.000 claims description 5
- 238000001816 cooling Methods 0.000 claims description 5
- 239000000463 material Substances 0.000 claims description 5
- 238000004321 preservation Methods 0.000 claims description 5
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 claims description 4
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 4
- 239000012141 concentrate Substances 0.000 claims description 4
- 229910052759 nickel Inorganic materials 0.000 claims description 4
- 150000003467 sulfuric acid derivatives Chemical class 0.000 claims description 4
- 229910001567 cementite Inorganic materials 0.000 claims description 2
- 229910017052 cobalt Inorganic materials 0.000 claims description 2
- 239000010941 cobalt Substances 0.000 claims description 2
- 229910000428 cobalt oxide Inorganic materials 0.000 claims description 2
- IVMYJDGYRUAWML-UHFFFAOYSA-N cobalt(ii) oxide Chemical compound [Co]=O IVMYJDGYRUAWML-UHFFFAOYSA-N 0.000 claims description 2
- 229910000480 nickel oxide Inorganic materials 0.000 claims description 2
- GNRSAWUEBMWBQH-UHFFFAOYSA-N oxonickel Chemical compound [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 claims description 2
- 239000012279 sodium borohydride Substances 0.000 claims description 2
- 229910000033 sodium borohydride Inorganic materials 0.000 claims description 2
- 230000032683 aging Effects 0.000 claims 1
- 238000001035 drying Methods 0.000 claims 1
- 238000003756 stirring Methods 0.000 claims 1
- 239000002994 raw material Substances 0.000 abstract description 5
- 239000012535 impurity Substances 0.000 abstract description 4
- 238000004134 energy conservation Methods 0.000 abstract description 3
- 230000007613 environmental effect Effects 0.000 abstract description 3
- 150000003839 salts Chemical class 0.000 abstract description 3
- 238000004519 manufacturing process Methods 0.000 abstract description 2
- 238000011084 recovery Methods 0.000 abstract description 2
- 239000000126 substance Substances 0.000 description 7
- 238000005516 engineering process Methods 0.000 description 4
- 238000005188 flotation Methods 0.000 description 4
- 150000001247 metal acetylides Chemical class 0.000 description 4
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 description 3
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 3
- 239000003792 electrolyte Substances 0.000 description 3
- 150000007522 mineralic acids Chemical class 0.000 description 3
- 229910017604 nitric acid Inorganic materials 0.000 description 3
- 238000000926 separation method Methods 0.000 description 3
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 229910001610 cryolite Inorganic materials 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000003628 erosive effect Effects 0.000 description 2
- 150000002222 fluorine compounds Chemical class 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 150000002825 nitriles Chemical class 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 230000035484 reaction time Effects 0.000 description 2
- PUZPDOWCWNUUKD-UHFFFAOYSA-M sodium fluoride Chemical compound [F-].[Na+] PUZPDOWCWNUUKD-UHFFFAOYSA-M 0.000 description 2
- 229910052723 transition metal Inorganic materials 0.000 description 2
- 150000003624 transition metals Chemical class 0.000 description 2
- HLLSOEKIMZEGFV-UHFFFAOYSA-N 4-(dibutylsulfamoyl)benzoic acid Chemical compound CCCCN(CCCC)S(=O)(=O)C1=CC=C(C(O)=O)C=C1 HLLSOEKIMZEGFV-UHFFFAOYSA-N 0.000 description 1
- XFXPMWWXUTWYJX-UHFFFAOYSA-N Cyanide Chemical compound N#[C-] XFXPMWWXUTWYJX-UHFFFAOYSA-N 0.000 description 1
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 description 1
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 1
- 229910002651 NO3 Inorganic materials 0.000 description 1
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 1
- 238000001069 Raman spectroscopy Methods 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 239000004411 aluminium Substances 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 229910003481 amorphous carbon Inorganic materials 0.000 description 1
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 description 1
- 229910001634 calcium fluoride Inorganic materials 0.000 description 1
- 229910021386 carbon form Inorganic materials 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 230000001010 compromised effect Effects 0.000 description 1
- 239000011258 core-shell material Substances 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000003682 fluorination reaction Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 229910021389 graphene Inorganic materials 0.000 description 1
- 239000007770 graphite material Substances 0.000 description 1
- 239000003673 groundwater Substances 0.000 description 1
- 229910000040 hydrogen fluoride Inorganic materials 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000011229 interlayer Substances 0.000 description 1
- 239000010410 layer Substances 0.000 description 1
- 239000012633 leachable Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- LGQLOGILCSXPEA-UHFFFAOYSA-L nickel sulfate Chemical compound [Ni+2].[O-]S([O-])(=O)=O LGQLOGILCSXPEA-UHFFFAOYSA-L 0.000 description 1
- 229910000363 nickel(II) sulfate Inorganic materials 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- 238000002407 reforming Methods 0.000 description 1
- 239000011775 sodium fluoride Substances 0.000 description 1
- 235000013024 sodium fluoride Nutrition 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 239000002341 toxic gas Substances 0.000 description 1
- 231100000419 toxicity Toxicity 0.000 description 1
- 230000001988 toxicity Effects 0.000 description 1
- 238000003828 vacuum filtration Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/20—Graphite
- C01B32/205—Preparation
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Inorganic Chemistry (AREA)
- Carbon And Carbon Compounds (AREA)
- Catalysts (AREA)
Abstract
The invention discloses a method for preparing high-quality graphite by catalytic graphitization of waste cathode carbon, and relates to the technical field of aluminum electrolysis waste cathode carbon recovery. Crushing the waste cathode carbon blocks, and realizing harmless treatment of the waste cathode carbon by alkaline leaching. Uniformly mixing the waste cathode carbon powder subjected to impurity removal with a catalyst, and carrying out catalytic graphitization treatment under the microwave condition. The resultant product was crushed using a ball mill, and then the catalyst and graphite were separated by wet magnetic separation. The catalyst is reused, and the residual catalyst is removed by acid leaching of the graphite, so that high-quality graphite is obtained. Adding ethanol into the pickling solution, filtering to recover metal salt crystals, respectively recovering ethanol by two-stage evaporation of the acid solution, and concentrating the acid solution for recycling. The method has the advantages of low raw material price, high added value of products, energy conservation, high efficiency, environmental protection and easy industrialized mass production.
Description
Technical Field
The invention relates to the technical field of aluminum electrolysis waste cathode carbon recovery, in particular to a method for preparing high-quality graphite by catalytic graphitization of waste cathode carbon.
Background
The cathode carbon block in the aluminum electrolysis cell can deform and break after being used for 4-7 years under the influence of mechanical erosion, chemical erosion and electrolyte permeation due to long-term contact with high-temperature aluminum liquid and electrolyte. The cathode carbon forms a spent cathode carbon block on the basis of absorbing a large amount of harmful substances such as soluble fluorides, cyanides and the like. And the soluble fluoride and cyanide content is well above the safe emission standards. If the aluminum electrolysis waste cathode carbon block is improperly treated (e.g., piled up or buried in the open air), soluble fluorides and cyanides may be dissolved and diffused into soil and groundwater, causing serious damage to the ecological environment. Therefore, the aluminum electrolysis waste cathode carbon block is considered as dangerous waste due to toxicity and leachable property, and harmless treatment is urgently needed. With the rapid development of the electrolytic aluminum industry, the problem of innocent treatment of the aluminum electrolysis waste cathode carbon blocks becomes increasingly prominent, and the problem of bottleneck for restricting the development of the aluminum industry is formed.
The main components of the aluminum electrolysis waste cathode carbon block are carbon, sodium fluoride, cryolite, calcium fluoride, aluminum oxide and the like. The current common treatment methods of the aluminum electrolysis waste cathode carbon block are flotation, heat treatment, fixed fluorination, leaching and the like. However, the above methods have limitations in facing the complex impurities in the spent cathode carbon of aluminum electrolysis. Flotation is used as a physical separation method, and the flotation process is long, so that the separation efficiency is low, and the flotation can only be used as a primary separation process. If only aluminum electrolysis spent cathode carbon blocks are used as a fuel, the highly graphitized spent cathode carbon is wasted during the heat treatment. Patent CN111232947a proposes that dilute sulfuric acid purifies waste cathode carbon of aluminum electrolysis, but acid leaching cannot remove alumina therein, and the dilute sulfuric acid also reacts with cryolite to generate a great deal of toxic gas hydrogen fluoride. The harmless treatment mode cannot deeply remove toxic impurities and does not fully utilize carbon materials in the harmless treatment mode, so that a novel harmless treatment mode for utilizing carbon components in the waste cathode carbon at a high value is urgently needed.
The carbon content in the aluminum electrolysis spent cathode carbon block is about 60%, which is subjected to carbon fixation by a large number of related researchers and practitioners, and the resulting spent cathode carbon powder is used for preparing graphite-based derivative applications. However, the waste cathode carbon block is in a layered structure, a large amount of fluoride is mixed in the waste cathode carbon block, and the common innocent treatment can not remove the fluoride between graphite layers. And although the graphitization degree of the waste cathode carbon of the aluminum electrolysis is improved compared with that of the raw materials, the graphitization degree of the waste cathode carbon of the aluminum electrolysis is obviously different from that of commercial graphite. Patent CN107200320a proposes the preparation of expanded graphite or graphene from electrolytic aluminum spent cathode carbon. However, due to the impurity doping of the spent cathode carbon, the graphitization degree is lower than that of commercial graphite, and the function and effect of the carbonaceous derivative application produced by the spent cathode carbon are greatly compromised. In order to realize high-efficiency and high-added-value utilization of carbonaceous resources, a graphitization technology is taken as an effective means in the preparation technology link of graphite materials, and is widely and deeply researched by students at home and abroad in recent years, but the conventional graphitization technology is not applicable to graphitization of waste cathode carbon. In the aluminium electrolysis process, the amorphous carbon component in the cathode carbon block raw material is graphitized in the electrolyte salt through electrochemical reforming, so the graphitization degree is improved to 60% -88%. High-temperature graphitization and molten salt electrolysis graphitization of the aluminum electrolysis waste cathode carbon cannot realize further improvement of graphitization degree. How to effectively realize the deep graphitization of the aluminum electrolysis waste cathode carbon becomes a technical problem to be solved in the industry field. The graphitization process is catalyzed, and the catalyst and graphite products form a core-shell structure, so that the patent CN114291806A uses inorganic acid to wash to remove the metal catalyst. And this results in a waste of a large amount of catalyst and an increase in the amount of inorganic acid used, resulting in a significant increase in the cost of preparing catalytic graphite. How to recycle the catalyst in the catalytic graphite product becomes a critical problem in catalytic graphitization industrialization.
Disclosure of Invention
The invention provides a method for preparing high-quality graphite by catalytic graphitization of waste cathode carbon, which aims to solve the problems in the background technology.
The scheme of the invention is as follows:
a method for preparing high-quality graphite by catalytic graphitization of waste cathode carbon comprises the following steps:
s1, crushing, grinding and screening the aluminum electrolysis waste cathode carbon blocks to obtain waste cathode carbon powder; then, leaching the waste cathode carbon powder by adopting alkaline solution to realize harmless treatment of the waste cathode carbon;
s2, uniformly mixing the alkaline leached waste cathode carbon powder with a metal catalyst, filling the mixture into a corundum crucible, and then carrying out catalytic graphitization treatment in a microwave high-temperature atmosphere furnace to obtain a graphitized product;
s3, crushing graphitized products by using a ball mill, separating out a metal catalyst by wet magnetic separation, carrying out sulfuric acid washing on the separated graphite components, and carrying out suction filtration to obtain graphite with high graphitization degree and pickling solution respectively;
s4, adding ethanol into the pickling solution, uniformly mixing, and filtering a crystal; the filtered pickling solution is subjected to first-stage evaporation to recover ethanol, and then second-stage evaporation is performed to concentrate at high temperature to increase the concentration of sulfuric acid, so that the recycling of ethanol and sulfuric acid is realized.
As an optimal technical scheme, the waste cathode carbon blocks in the step S1 are crushed by a crusher and a ball mill in sequence, and the waste cathode carbon powder with the particle size of 50-200 meshes is obtained by screening.
As a preferable technical scheme, the alkaline solution in the step S1 is one or a mixture of more of sodium hydroxide, potassium hydroxide and sodium borohydride; the concentration of the alkaline solution in the leaching is 0.5-2 mol/L, the liquid-solid ratio of the alkaline solution in the leaching to the waste cathode carbon powder is 5-15:1, the temperature in the leaching is 20-50 ℃, and the leaching time is 1-4 h.
As a preferable technical scheme, the metal catalyst in S2 is one or a mixture of more of elemental iron, elemental cobalt, elemental nickel, iron carbide, cobalt carbide, nickel carbide, iron oxide, cobalt oxide and nickel oxide; the waste cathode carbon powder and the metal catalyst are uniformly mixed according to the mass ratio of 1-5:1, are filled into a corundum crucible, and are placed into a microwave high-temperature atmosphere furnace.
As a preferred embodiment, the metal catalyst is iron or a carbide thereof.
As an optimal technical scheme, the microwave catalytic graphitization in the S2 is performed under the argon atmosphere, the reaction temperature is 1150-1600 ℃, the heat preservation time is 30-120 min, and the graphitization product is obtained after cooling.
As a preferable technical scheme, after the ball mill in the step S3 breaks the treated product, the powder material product with the particle size of 1-3 mu m accounts for more than 30wt% of the total product.
As an preferable technical scheme, the magnetic field strength of the magnetic separation process of the wet magnetic separation in the step S3 is 1800-2500 oersted, the separated magnetic particles are metal catalysts, and the magnetic particles are still used for microwave catalytic graphitization after being collected.
As a preferable technical scheme, the graphite component separated by magnetic separation in the S3 is subjected to acid washing by using a sulfuric acid solution with the concentration of 4-6 mol/L, the acid washing temperature is 50-80 ℃, and the acid washing time is 8-12 h; and (3) after the acid washing is finished, carrying out vacuum filtration on the solution, and obtaining powder which is the graphite with high graphitization degree.
As a preferable technical scheme, the pickling solution in the S4 is mixed with 70-95% ethanol according to the volume ratio of 1:1-3, stirred for 30-60 min and aged for 1-4 h; the resulting crystals were filtered, which were the sulfate salts of the metal catalysts.
As a preferable technical scheme, the first section in the step S4 is evaporated to recover ethanol, the temperature is set at 60-80 ℃, and the temperature is kept for 45-60 min; the second-stage evaporation is carried out for high-temperature concentration, the temperature is set at 160-270 ℃, and the concentration of sulfuric acid is 5mol/L (the concentration is 26.63%). Sulfuric acid and ethanol are recycled.
Due to the adoption of the technical scheme, the method for preparing high-quality graphite by catalytic graphitization of the waste cathode carbon comprises the following steps of: s1, crushing, grinding and screening the aluminum electrolysis waste cathode carbon blocks to obtain waste cathode carbon powder; then, leaching the waste cathode carbon powder by adopting alkaline solution to realize harmless treatment of the waste cathode carbon; s2, uniformly mixing the alkaline leached waste cathode carbon powder with a metal catalyst, filling the mixture into a corundum crucible, and then carrying out catalytic graphitization treatment in a microwave high-temperature atmosphere furnace to obtain a graphitized product; s3, crushing graphitized products by using a ball mill, separating out a metal catalyst by wet magnetic separation, carrying out sulfuric acid washing on the separated graphite components, and carrying out suction filtration to obtain graphite with high graphitization degree and pickling solution respectively; s4, adding ethanol into the pickling solution, uniformly mixing, and filtering a crystal; the filtered pickling solution is subjected to first-stage evaporation to recover ethanol, and then second-stage evaporation is performed to concentrate at high temperature to increase the concentration of sulfuric acid, so that the recycling of ethanol and sulfuric acid is realized.
The invention has the advantages that:
the method takes harmless waste cathode carbon powder as a carbon source, mixes the carbon powder with a transition metal catalyst, heats the mixture to 1300 ℃ under the microwave condition, and keeps the temperature for 30min, thereby realizing the graphitization degree of 98.2%. Successfully reduces the graphitization temperature from 2800 ℃ to 3200 ℃ to 1300 ℃, reduces the graphitization time from 6 to 24 hours to 30 minutes, and prepares a graphite product superior to commercial flaky graphite.
The method is to realize the recycling of the catalyst and the complete removal of the catalyst components in the graphite, and carry out crushing treatment and wet magnetic separation on the catalyst components. The separated magnetic substance is a catalyst and carbide thereof, and returns to the step of catalytic graphitization for recycling. The separated spheroidal graphite has its surface destroyed, exposing the residual catalyst inside the sphere. And (3) carrying out acid washing on the graphite component by using a 5mol/L sulfuric acid solution to completely remove iron wrapped by graphite, thereby obtaining high-purity graphite.
The method is to recycle valuable components in the pickling solution, and recycle the sulfate of the transition metal by using an ethanol solution crystallization method by utilizing the characteristics that the metal sulfate is easily soluble in water and is difficult to dissolve or insoluble in ethanol solution. Two-stage evaporation is adopted to respectively recover ethanol and concentrate inorganic acid for recycling.
The method has the advantages of low raw material price, high added value of products, energy conservation, high efficiency, environmental protection and easy industrialized mass production;
the Id/Ig ratio of the graphite prepared by using the aluminum electrolysis waste cathode carbon is reduced from 1.05 to 0.08, the graphitization degree is improved from 87.02% to 98.81%, and the graphitization degree is calculated to exceed that of commercial flake graphite (97.8%).
Drawings
FIG. 1 is a process flow diagram of example 1 of the present invention;
FIG. 2 is an XRD pattern of the spent cathode carbon block and product high quality graphite of example 1 of the present invention;
fig. 3 is a Raman diagram of the spent cathode carbon block and the product high quality graphite of example 1 of the present invention.
Detailed Description
The invention is further described in connection with the following embodiments in order to make the technical means, the creation features, the achievement of the purpose and the effect of the invention easy to understand.
Example 1:
s1, crushing, grinding and screening the aluminum electrolysis waste cathode carbon blocks to obtain waste cathode carbon powder with the particle size of 50-200 meshes.
S2, carrying out alkaline leaching treatment by adopting a potassium hydroxide solution, wherein the alkaline leaching concentration is 1.25mol/L, the alkaline leaching solid ratio is 5:1, the alkaline leaching temperature is normal temperature, and the alkaline leaching time is 4 hours, so as to realize harmless treatment of the waste cathode carbon.
S3, uniformly mixing the alkaline leached waste cathode carbon powder and iron powder, filling the mixture into a corundum crucible, and placing the corundum crucible into a microwave high-temperature atmosphere furnace for microwave catalytic graphitization. The microwave catalytic graphitization is carried out under the argon atmosphere, the reaction temperature is 1300 ℃, the heat preservation time is 30min, and the product is obtained after cooling.
S4, crushing and treating the graphitized product by using a ball mill, so that the 1-3 mu m powder material accounts for more than 30wt% of the total amount. The magnetic field intensity of the wet magnetic separation process is 2500 Oerst, the separated magnetic particles are simple substances of the catalyst and carbides thereof, and the catalyst is collected for the next round of microwave catalytic graphitization.
And (3) pickling the graphite component obtained by wet magnetic separation by using a nitric acid solution with the concentration of 5mol/L, wherein the pickling temperature is 60 ℃, and the pickling time is 8 hours. And after the reaction is finished, carrying out vacuum suction filtration on the solution, wherein the graphitization degree of the obtained graphite is 98.91%.
The pickling solution and 95% ethanol are mixed according to the volume ratio of 1:2, stirred for 30min and aged for 1h. The resulting crystals were filtered and the crystals were ferrous nitrate.
And (3) performing first-stage evaporation on the filtered and crystallized solution to recover ethanol, setting the temperature at 78 ℃, and preserving the temperature for 45min. Then, high-temperature concentration was performed by two-stage evaporation, the temperature was set at 220℃and nitric acid was concentrated to 5mol/L (concentration: 26.63%). The nitric acid and the ethanol are repeatedly utilized.
Table 1 shows the properties of the products obtained in example 1 at different temperatures
| Sample of | Interlayer spacing (nm) | Degree of graphitization (%) |
| Raw materials | 0.3365 | 87.02 |
| Catalytic graphite (1155 ℃ C.) | 0.3360 | 92.96 |
| Catalytic graphite (1200 ℃ C.) | 0.3358 | 95.27 |
| Catalytic graphite (1300 ℃ C.) | 0.3354 | 98.91 |
| Commercial flake graphite | 0.3356 | 97.87 |
Example 2:
s1, crushing, grinding and screening the aluminum electrolysis waste cathode carbon blocks to obtain waste cathode carbon powder with the particle size of 50-200 meshes.
S2, performing alkaline leaching treatment by adopting a sodium hydroxide solution, wherein the alkaline leaching concentration is 1.25mol/L, the alkaline leaching solid ratio is 5:1, the alkaline leaching temperature is normal temperature, and the alkaline leaching time is 4 hours, so as to realize harmless treatment of the waste cathode carbon.
S3, uniformly mixing the alkaline leached waste cathode carbon powder and nickel powder, filling the mixture into a corundum crucible, and placing the corundum crucible into a microwave high-temperature atmosphere furnace for microwave catalytic graphitization. The microwave catalytic graphitization is carried out under the argon atmosphere, the reaction temperature is 1300 ℃, the heat preservation time is 30min, and the product is obtained after cooling.
S4, crushing and treating the graphitized product by using a ball mill, so that the 1-3 mu m powder material accounts for more than 30wt% of the total amount. The magnetic field intensity in the wet magnetic separation process is 2500 oersted, the separated magnetic particles are catalyst simple substances and carbides thereof, and the magnetic particles are still used for microwave catalytic graphitization after being collected.
And the graphite component obtained by wet magnetic separation is subjected to acid washing by using a sulfuric acid solution with the concentration of 5mol/L, wherein the acid washing temperature is 60 ℃, and the acid washing time is 8 hours. And after the reaction is finished, carrying out vacuum suction filtration on the solution, wherein the graphitization degree of the obtained graphite is 98.84%.
The pickling solution and 95% ethanol are mixed according to the volume ratio of 1:2, stirred for 30min and aged for 1h. The resulting crystals were filtered, which were nickel sulfate.
And (3) performing first-stage evaporation on the filtered and crystallized solution to recover ethanol, setting the temperature at 78 ℃, and preserving the temperature for 45min. Then, high-temperature concentration was performed by two-stage evaporation, the temperature was set at 220℃and sulfuric acid was concentrated to 5mol/L (concentration: 26.63%). Sulfuric acid and ethanol are recycled.
Example 3:
s1, crushing, grinding and screening the aluminum electrolysis waste cathode carbon blocks to obtain waste cathode carbon powder with the particle size of 50-200 meshes.
S2, carrying out alkaline leaching treatment by adopting a potassium hydroxide solution, wherein the alkaline leaching concentration is 1.25mol/L, the alkaline leaching solid ratio is 5:1, the alkaline leaching temperature is normal temperature, and the alkaline leaching time is 4 hours, so as to realize harmless treatment of the waste cathode carbon.
S3, uniformly mixing the alkaline leached waste cathode carbon powder and iron powder, filling the mixture into a corundum crucible, and placing the corundum crucible into a microwave high-temperature atmosphere furnace for microwave catalytic graphitization. The microwave catalytic graphitization is carried out under the argon atmosphere, the reaction temperature is 1300 ℃, the heat preservation time is 30min, and the product is obtained after cooling.
S4, crushing and treating the graphitized product by using a ball mill, so that the 1-3 mu m powder material accounts for more than 30wt% of the total amount. The magnetic field intensity in the wet magnetic separation process is 2500 oersted, the separated magnetic particles are catalyst simple substances and carbides thereof, and the magnetic particles are still used for microwave catalytic graphitization after being collected.
And the graphite component obtained by wet magnetic separation is subjected to acid washing by using a sulfuric acid solution with the concentration of 5mol/L, wherein the acid washing temperature is 60 ℃, and the acid washing time is 8 hours. And after the reaction is finished, carrying out vacuum suction filtration on the solution, wherein the graphitization degree of the obtained graphite is 98.49%.
The pickling solution and 95% ethanol are mixed according to the volume ratio of 1:2, stirred for 30min and aged for 1h. The resulting crystals were filtered, which were the sulfate salts of the catalyst.
And (3) performing first-stage evaporation on the filtered and crystallized solution to recover ethanol, setting the temperature at 78 ℃, and preserving the temperature for 45min. Then, high-temperature concentration was performed by two-stage evaporation, the temperature was set at 220℃and sulfuric acid was concentrated to 5mol/L (concentration: 26.63%). Sulfuric acid and ethanol are recycled.
Comparative example 1:
crushing, grinding and screening the waste cathode carbon blocks to obtain waste cathode carbon powder with the particle size of 50-200 meshes.
And then, adopting sodium hydroxide solution to carry out alkaline leaching treatment, wherein the alkaline leaching concentration is 1.25mol/L, the alkaline leaching solid ratio is 5:1, the alkaline leaching temperature is normal temperature, and the alkaline leaching time is 4 hours, so as to realize harmless treatment of the waste cathode carbon.
And uniformly mixing the waste cathode carbon powder subjected to alkaline leaching with iron powder, filling the mixture into a corundum crucible, and placing the corundum crucible into a high-temperature resistance furnace for catalytic graphitization. The reaction temperature was 1600 ℃, the temperature was kept for 1h, and the experiment was performed under nitrogen atmosphere.
The graphitized product was crushed using a ball mill so that 1-3 μm powder accounted for more than 30wt% of the total amount. The magnetic field intensity in the wet magnetic separation process is 2500 oersted, the separated magnetic particles are catalyst simple substances and carbides thereof, and the magnetic particles are still used for microwave catalytic graphitization after being collected.
And (3) carrying out acid washing on the graphite component obtained by wet magnetic separation by using a sulfuric acid solution with the concentration of 5mol/L, wherein the acid washing temperature is 60 ℃, and the acid washing time is 8 hours. And after the reaction is finished, carrying out vacuum suction filtration on the solution, wherein the graphitization degree of the obtained graphite is 97.23%.
The pickling solution and 95% ethanol are mixed according to the volume ratio of 1:2, stirred for 30min and aged for 1h. The resulting crystals were filtered, which were the sulfate salts of the catalyst.
And (3) performing first-stage evaporation on the filtered and crystallized solution to recover ethanol, setting the temperature at 78 ℃, and preserving the temperature for 45min. Then, high-temperature concentration was performed by two-stage evaporation, the temperature was set at 220℃and sulfuric acid was concentrated to 5mol/L (concentration: 26.63%). Sulfuric acid and ethanol are recycled.
Comparative example 1 was used to verify that microwave catalyzed graphitization is superior to high temperature graphitization and conventional heated catalyzed graphitization, and reduced reaction temperature and reaction time while achieving higher product graphitization. The method has the advantages of low temperature required by graphitization, short reaction time, energy conservation and environmental protection, and is favorable for preparing high-quality graphite by using the waste cathode carbon in a large-scale industrialized mode.
The foregoing has shown and described the basic principles, main features and advantages of the present invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and that the above embodiments and descriptions are merely illustrative of the principles of the present invention, and various changes and modifications may be made without departing from the spirit and scope of the invention, which is defined in the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.
Claims (10)
1. The method for preparing high-quality graphite by catalytic graphitization of waste cathode carbon is characterized by comprising the following steps:
s1, crushing, grinding and screening the aluminum electrolysis waste cathode carbon blocks to obtain waste cathode carbon powder; then, leaching the waste cathode carbon powder by adopting alkaline solution to realize harmless treatment of the waste cathode carbon;
s2, uniformly mixing the alkaline leached waste cathode carbon powder with a metal catalyst, filling the mixture into a corundum crucible, and then carrying out catalytic graphitization treatment in a microwave high-temperature atmosphere furnace to obtain a graphitized product;
s3, crushing graphitized products by using a ball mill, separating out a metal catalyst by wet magnetic separation, carrying out sulfuric acid washing on the separated graphite components, and carrying out suction filtration to obtain graphite with high graphitization degree and pickling solution respectively;
s4, adding ethanol into the pickling solution, uniformly mixing, and filtering a crystal; the filtered pickling solution is subjected to first-stage evaporation to recover ethanol, and then second-stage evaporation is performed to concentrate at high temperature to increase the concentration of sulfuric acid, so that the recycling of ethanol and sulfuric acid is realized.
2. The method for preparing high-quality graphite by catalytic graphitization of waste cathode carbon according to claim 1, wherein the method comprises the following steps: and (2) crushing the waste cathode carbon blocks in the step S1 by adopting a crusher and a ball mill in sequence, and screening to obtain the waste cathode carbon powder with the particle size of 50-200 meshes.
3. The method for preparing high-quality graphite by catalytic graphitization of waste cathode carbon according to claim 1, wherein the method comprises the following steps: the alkaline solution in the step S1 is one or a mixture of more of sodium hydroxide, potassium hydroxide and sodium borohydride; the concentration of the alkaline solution in the leaching is 0.5-2 mol/L, the liquid-solid ratio of the alkaline solution in the leaching to the waste cathode carbon powder is 5-15:1, the temperature in the leaching is 20-50 ℃, and the leaching time is 1-4 h.
4. The method for preparing high-quality graphite by catalytic graphitization of waste cathode carbon according to claim 1, wherein the method comprises the following steps: the metal catalyst in the S2 is one or a mixture of more of elemental iron, elemental cobalt, elemental nickel, iron carbide, cobalt carbide, nickel carbide, iron oxide, cobalt oxide and nickel oxide; the waste cathode carbon powder and the metal catalyst are uniformly mixed according to the mass ratio of 1-5:1, are filled into a corundum crucible, and are placed into a microwave high-temperature atmosphere furnace.
5. The method for preparing high-quality graphite by catalytic graphitization of waste cathode carbon according to claim 1, wherein the method comprises the following steps: and (2) carrying out microwave catalytic graphitization in the S2 under the argon atmosphere, wherein the reaction temperature is 1150-1600 ℃, the heat preservation time is 30-120 min, and cooling to obtain a graphitized product.
6. The method for preparing high-quality graphite by catalytic graphitization of waste cathode carbon according to claim 1, wherein the method comprises the following steps: after the ball mill in the step S3 breaks the processed product, the powder material product with the particle size of 1-3 mu m accounts for more than 30wt% of the total product.
7. The method for preparing high-quality graphite by catalytic graphitization of waste cathode carbon according to claim 1, wherein the method comprises the following steps: the magnetic field intensity of the wet magnetic separation process in the step S3 is 1800-2500 Oersted, the separated magnetic particles are metal catalysts, and the collected magnetic particles are still used for microwave catalytic graphitization.
8. The method for preparing high-quality graphite by catalytic graphitization of waste cathode carbon according to claim 1, wherein the method comprises the following steps: the graphite component separated by magnetic separation in the step S3 is subjected to acid washing by using sulfuric acid solution with the concentration of 4-6 mol/L, the acid washing temperature is 50-80 ℃, and the acid washing time is 8-12 h; and after the pickling reaction is finished, washing, suction filtering and drying are carried out, and the obtained powder is the graphite with high graphitization degree.
9. The method for preparing high-quality graphite by catalytic graphitization of waste cathode carbon according to claim 1, wherein the method comprises the following steps: mixing the pickling solution in the step S4 with 70-95% ethanol in a volume ratio of 1:1-3, stirring for 30-60 min, and aging for 1-4 h; the resulting crystals were filtered, which were the sulfate salts of the metal catalysts.
10. The method for preparing high-quality graphite by catalytic graphitization of waste cathode carbon according to claim 1, wherein the method comprises the following steps: the first section in the step S4 is evaporated to recover ethanol, the temperature is set at 60-80 ℃, and the temperature is kept for 45-60 min; the second-stage evaporation is carried out for high-temperature concentration, the temperature is set at 160-270 ℃, and the sulfuric acid is concentrated to 5mol/L.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105132950A (en) * | 2015-09-09 | 2015-12-09 | 郑州经纬科技实业有限公司 | System and method for producing fully-graphitized carbon product through waste cathode carbon blocks of electrolyzed aluminum |
| JP2017145151A (en) * | 2016-02-15 | 2017-08-24 | 新日鐵住金株式会社 | Graphite crystallization treatment method of amorphous carbon material, product generated during recovering graphite and graphite |
| CN107857263A (en) * | 2017-11-28 | 2018-03-30 | 国家电投集团远达环保催化剂有限公司 | A kind of ultrasonic wave alkali leaching and the method for pressurized acid leaching Combined Treatment electrolytic aluminium waste cathode carbon block |
| CN112624101A (en) * | 2020-12-23 | 2021-04-09 | 河南省冶金研究所有限责任公司 | Process for wet treatment of electrolytic aluminum waste cathode material |
| CN114644340A (en) * | 2020-12-17 | 2022-06-21 | 卢序 | Preparation method of low-salt silica sol |
| CN114749465A (en) * | 2022-05-02 | 2022-07-15 | 郑州大学 | Method for purifying aluminum electrolysis waste cathode carbon and preparing porous carbon adsorbent |
-
2023
- 2023-09-28 CN CN202311272454.XA patent/CN117263178B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105132950A (en) * | 2015-09-09 | 2015-12-09 | 郑州经纬科技实业有限公司 | System and method for producing fully-graphitized carbon product through waste cathode carbon blocks of electrolyzed aluminum |
| JP2017145151A (en) * | 2016-02-15 | 2017-08-24 | 新日鐵住金株式会社 | Graphite crystallization treatment method of amorphous carbon material, product generated during recovering graphite and graphite |
| CN107857263A (en) * | 2017-11-28 | 2018-03-30 | 国家电投集团远达环保催化剂有限公司 | A kind of ultrasonic wave alkali leaching and the method for pressurized acid leaching Combined Treatment electrolytic aluminium waste cathode carbon block |
| CN114644340A (en) * | 2020-12-17 | 2022-06-21 | 卢序 | Preparation method of low-salt silica sol |
| CN112624101A (en) * | 2020-12-23 | 2021-04-09 | 河南省冶金研究所有限责任公司 | Process for wet treatment of electrolytic aluminum waste cathode material |
| CN114749465A (en) * | 2022-05-02 | 2022-07-15 | 郑州大学 | Method for purifying aluminum electrolysis waste cathode carbon and preparing porous carbon adsorbent |
Non-Patent Citations (1)
| Title |
|---|
| 成来飞: "复合材料原理及工艺", 31 March 2018, 西北工业大学出版社, pages: 226 - 227 * |
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