CN114634189B - Recovery method and system for aluminum electrolysis overhaul slag - Google Patents
Recovery method and system for aluminum electrolysis overhaul slag Download PDFInfo
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- CN114634189B CN114634189B CN202210211645.4A CN202210211645A CN114634189B CN 114634189 B CN114634189 B CN 114634189B CN 202210211645 A CN202210211645 A CN 202210211645A CN 114634189 B CN114634189 B CN 114634189B
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- 239000002893 slag Substances 0.000 title claims abstract description 97
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 title claims abstract description 73
- 229910052782 aluminium Inorganic materials 0.000 title claims abstract description 73
- 238000005868 electrolysis reaction Methods 0.000 title claims abstract description 68
- 238000011084 recovery Methods 0.000 title claims abstract description 50
- 238000000034 method Methods 0.000 title claims abstract description 44
- 239000007788 liquid Substances 0.000 claims abstract description 175
- 238000002386 leaching Methods 0.000 claims abstract description 141
- 238000000926 separation method Methods 0.000 claims abstract description 67
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 65
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 claims abstract description 30
- 238000004064 recycling Methods 0.000 claims abstract description 25
- PUZPDOWCWNUUKD-UHFFFAOYSA-M sodium fluoride Chemical compound [F-].[Na+] PUZPDOWCWNUUKD-UHFFFAOYSA-M 0.000 claims description 58
- 239000002699 waste material Substances 0.000 claims description 37
- 238000003756 stirring Methods 0.000 claims description 35
- 239000000047 product Substances 0.000 claims description 31
- 239000011775 sodium fluoride Substances 0.000 claims description 29
- 235000013024 sodium fluoride Nutrition 0.000 claims description 29
- XFXPMWWXUTWYJX-UHFFFAOYSA-N Cyanide Chemical compound N#[C-] XFXPMWWXUTWYJX-UHFFFAOYSA-N 0.000 claims description 23
- 239000007787 solid Substances 0.000 claims description 21
- PQXKHYXIUOZZFA-UHFFFAOYSA-M lithium fluoride Chemical compound [Li+].[F-] PQXKHYXIUOZZFA-UHFFFAOYSA-M 0.000 claims description 20
- 239000013078 crystal Substances 0.000 claims description 19
- 230000008569 process Effects 0.000 claims description 17
- 238000001914 filtration Methods 0.000 claims description 15
- 239000011819 refractory material Substances 0.000 claims description 15
- 239000000843 powder Substances 0.000 claims description 14
- 238000006243 chemical reaction Methods 0.000 claims description 13
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims description 12
- 238000002425 crystallisation Methods 0.000 claims description 12
- 230000008025 crystallization Effects 0.000 claims description 12
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 claims description 10
- 229910052731 fluorine Inorganic materials 0.000 claims description 10
- 239000011737 fluorine Substances 0.000 claims description 10
- 238000005406 washing Methods 0.000 claims description 9
- 239000003795 chemical substances by application Substances 0.000 claims description 8
- 238000001035 drying Methods 0.000 claims description 7
- 238000001704 evaporation Methods 0.000 claims description 6
- 238000000605 extraction Methods 0.000 claims description 5
- 239000000706 filtrate Substances 0.000 claims description 5
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims description 4
- 239000012153 distilled water Substances 0.000 claims description 4
- 229910052744 lithium Inorganic materials 0.000 claims description 4
- 238000007711 solidification Methods 0.000 claims description 4
- 230000008023 solidification Effects 0.000 claims description 4
- 238000002156 mixing Methods 0.000 claims description 3
- 238000005201 scrubbing Methods 0.000 claims description 3
- 239000000126 substance Substances 0.000 description 9
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 6
- 238000006115 defluorination reaction Methods 0.000 description 6
- 230000004048 modification Effects 0.000 description 5
- 238000012986 modification Methods 0.000 description 5
- 238000013019 agitation Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 230000009471 action Effects 0.000 description 3
- 239000004566 building material Substances 0.000 description 3
- 230000008020 evaporation Effects 0.000 description 3
- 150000004673 fluoride salts Chemical class 0.000 description 3
- 239000013505 freshwater Substances 0.000 description 3
- 229910001105 martensitic stainless steel Inorganic materials 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 229910000029 sodium carbonate Inorganic materials 0.000 description 3
- 239000007790 solid phase Substances 0.000 description 3
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 description 2
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 2
- 229910000963 austenitic stainless steel Inorganic materials 0.000 description 2
- 239000001110 calcium chloride Substances 0.000 description 2
- 229910001628 calcium chloride Inorganic materials 0.000 description 2
- OSGAYBCDTDRGGQ-UHFFFAOYSA-L calcium sulfate Chemical compound [Ca+2].[O-]S([O-])(=O)=O OSGAYBCDTDRGGQ-UHFFFAOYSA-L 0.000 description 2
- 238000007599 discharging Methods 0.000 description 2
- 229910001039 duplex stainless steel Inorganic materials 0.000 description 2
- 239000003344 environmental pollutant Substances 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 239000002920 hazardous waste Substances 0.000 description 2
- 229910000040 hydrogen fluoride Inorganic materials 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 229910001506 inorganic fluoride Inorganic materials 0.000 description 2
- JMANVNJQNLATNU-UHFFFAOYSA-N oxalonitrile Chemical compound N#CC#N JMANVNJQNLATNU-UHFFFAOYSA-N 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 238000005192 partition Methods 0.000 description 2
- 231100000614 poison Toxicity 0.000 description 2
- 231100000719 pollutant Toxicity 0.000 description 2
- 230000008719 thickening Effects 0.000 description 2
- 239000003440 toxic substance Substances 0.000 description 2
- 239000002351 wastewater Substances 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 125000001153 fluoro group Chemical group F* 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
- C01D3/00—Halides of sodium, potassium or alkali metals in general
- C01D3/02—Fluorides
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
- C01D15/00—Lithium compounds
- C01D15/04—Halides
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/80—Compositional purity
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Inorganic Chemistry (AREA)
- Processing Of Solid Wastes (AREA)
- Electrolytic Production Of Metals (AREA)
- Manufacture And Refinement Of Metals (AREA)
Abstract
The application discloses a recovery method and a recovery system of aluminum electrolysis overhaul slag, which relate to the technical field of aluminum industry, can improve the recovery rate and recovery purity of fluoride, save water and avoid secondary pollution. The recovery method of the aluminum electrolysis overhaul slag comprises the following steps: carrying out at least one leaching and at least one solid-liquid separation on the aluminum electrolysis overhaul slag by using leaching liquid; recycling leaching solution obtained by solid-liquid separation.
Description
Technical Field
The application relates to the technical field of aluminum industry, in particular to a recycling method and system of aluminum electrolysis overhaul slag.
Background
The overhaul slag is slag generated in the process of repairing the breakage of the aluminum electrolysis cell and mainly comprises waste cathodes, waste refractory materials and the like. With the improvement of the aluminum output in China, the external discharge of overhaul slag is also increased year by year. The overhaul slag is an unavoidable solid dangerous waste in the aluminum electrolysis production, contains inorganic fluoride and cyanide which are toxic substances exceeding the standard, has extremely great harm to the environment, and is listed in the national hazardous waste directory, and the overhaul slag is urgently needed to be utilized and treated and is indistinct.
However, the existing overhaul slag recovery system improves the recovery rate of fluoride through repeated water washing, wastes water and generates wastewater to easily cause secondary pollution.
Disclosure of Invention
The embodiment of the application provides a recovery method and a recovery system for aluminum electrolysis overhaul slag, which can improve the recovery rate and recovery purity of fluoride, save water and avoid secondary pollution.
In a first aspect of the embodiments of the present application, a method for recovering aluminum electrolysis overhaul slag is provided, including:
carrying out at least one leaching and at least one solid-liquid separation on the aluminum electrolysis overhaul slag by using leaching liquid;
recycling leaching solution obtained by solid-liquid separation.
In some embodiments, the method further comprises, before at least one leaching and at least one solid-liquid separation of the aluminum electrolysis overhaul slag using the leaching solution:
classifying the aluminum electrolysis overhaul slag to obtain a waste cathode and a waste refractory material respectively;
and respectively preparing the waste cathode and the waste refractory material into powder to obtain waste cathode powder and waste refractory material powder.
In some embodiments, the at least one leaching and at least one solid-liquid separation of aluminum electrolysis overhaul slag using a leaching solution comprises:
performing primary leaching on the aluminum electrolysis overhaul slag by using the leaching solution, controlling the solid-to-liquid ratio to be in the range of 1:1-1:5, and controlling the leaching time to be in the range of 15-60min so as to dissolve cyanide and fluoride in the aluminum electrolysis overhaul slag and remove the cyanide by using a cyanide remover, wherein the cyanide remover comprises hydrogen peroxide;
carrying out solid-liquid separation on the solid-liquid mixed product after primary leaching;
performing secondary leaching on leaching slag obtained by solid-liquid separation after primary leaching, and controlling the solid-liquid ratio to be in the range of 1:1-1:5, wherein the leaching time is in the range of 15-60min so as to continuously dissolve fluoride in the leaching slag;
carrying out solid-liquid separation on the solid-liquid mixed product after the secondary leaching;
and recycling leaching solution obtained by solid-liquid separation after the secondary leaching in the primary leaching process.
In some embodiments, the utilizing leaching solution, at least one leaching and at least one solid-liquid separation of aluminum electrolysis overhaul slag, further comprises:
further curing fluoride in leaching residues obtained after secondary leaching by using a curing agent, and controlling the solid-liquid ratio to be in the range of 1:2-1:4, wherein the curing time is in the range of 15-60min;
carrying out solid-liquid separation on the further solidified leaching slag to obtain fluorine-fixing slag;
and recycling the liquid obtained by solid-liquid separation of the leaching residues which are further solidified to the further solidification of the fluoride.
In some embodiments, the recycling of the leaching solution obtained by solid-liquid separation comprises:
circulating the leaching solution obtained by solid-liquid separation after the primary leaching to obtain circulating liquid;
crystallizing the circulating liquid under the condition that the total dissolved solids of the circulating liquid is higher than 25 g/L;
and controlling the circulating liquid to be recycled in the secondary leaching under the condition that the total dissolved solids of the circulating liquid is 25g/L or less than 25 g/L.
In some embodiments, the crystallizing the circulating liquid in the case that the total dissolved solids of the circulating liquid is higher than 25g/L comprises:
purifying and filtering the circulating liquid under the condition that the total dissolved solids of the circulating liquid is higher than 25 g/L;
crystallizing the filtrate obtained by purifying and filtering to obtain sodium fluoride crystals;
washing the sodium fluoride crystals;
drying the washed sodium fluoride crystals;
extracting lithium fluoride from the concentrated solution obtained after crystallization.
In a second aspect of the embodiments of the present application, there is provided a recovery system of aluminum electrolysis overhaul slag, using the recovery method of aluminum electrolysis overhaul slag according to the first aspect, including:
the primary recovery subsystem comprises at least one stirring tank and at least one filter, wherein the stirring tank is used for carrying out solid-liquid mixing on aluminum electrolysis overhaul slag and leaching solution, and the filter is used for solid-liquid separation;
the secondary recovery subsystem comprises a first circulating water tank, an inlet of the first circulating water tank is communicated with at least one filter, and an outlet of the first circulating water tank is communicated with at least one stirring tank.
In some embodiments, the first-stage recovery subsystem comprises a first stirring tank, a second stirring tank, a first filter and a second filter, wherein the first filter is used for carrying out solid-liquid separation on the solid-liquid mixed product output by the first stirring tank, and the second filter is used for carrying out solid-liquid separation on the solid-liquid mixed product output by the second stirring tank;
the first stirring tank is communicated with a liquid outlet of the second filter, and the first circulating water tank is used for injecting the liquid output by the first filter into the second stirring tank after circulating;
the first circulating water tank is of a separation structure and is used for storing circulating liquid and distilled water respectively.
In some embodiments, the first-stage recovery subsystem further comprises a fluorine removal reaction bin, a solid-liquid separator and a second circulating water tank, wherein the fluorine removal reaction bin is respectively communicated with the solid-liquid separator and the second filter, the second circulating water tank is respectively communicated with the fluorine removal reaction bin and the solid-liquid separator, and the solid-liquid separator is used for obtaining fluorine-fixing slag.
In some embodiments, the secondary recovery subsystem further comprises:
the filtering purifier is used for purifying and filtering the liquid in the first circulating water tank;
the evaporator is used for evaporating and crystallizing the liquid obtained by filtering by the filtering purifier to obtain sodium fluoride crystals;
a scrubber for scrubbing the sodium fluoride crystals;
the dryer is used for drying the washed sodium fluoride crystals;
and the lithium extraction reaction bin is used for extracting lithium fluoride in the concentrated solution in the evaporator.
According to the recovery method and the recovery system for the aluminum electrolysis overhaul slag, at least one leaching and at least one solid-liquid separation are carried out on the aluminum electrolysis overhaul slag, harmful substances such as cyanide and the like can be removed after soluble substances in the aluminum electrolysis overhaul slag are dissolved, the leaching liquid obtained through the solid-liquid separation can be used for obtaining solid-phase fluoride through subsequent evaporation, the purity and the recovery rate of the fluoride are improved, the leaching liquid is recycled, new water can be not required to be repeatedly added, water can be saved, and secondary pollution cannot be caused.
Drawings
FIG. 1 is a schematic flow chart of a method for recycling aluminum electrolysis overhaul slag provided in an embodiment of the present application;
FIG. 2 is a schematic block diagram of a recycling system of aluminum electrolysis overhaul slag according to an embodiment of the present application;
fig. 3 is a schematic block diagram of another recovery system for aluminum electrolysis overhaul slag according to an embodiment of the present application.
Detailed Description
In order to better understand the technical solutions provided by the embodiments of the present specification, the following detailed description of the technical solutions of the embodiments of the present specification is made through the accompanying drawings and the specific embodiments, and it should be understood that the specific features of the embodiments of the present specification are detailed descriptions of the technical solutions of the embodiments of the present specification, and not limit the technical solutions of the present specification, and the technical features of the embodiments of the present specification may be combined with each other without conflict.
In this document, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element. The term "two or more" includes two or more cases.
The overhaul slag is slag generated in the process of repairing the breakage of the aluminum electrolysis cell and mainly comprises waste cathodes, waste refractory materials and the like. The yield of electrolytic aluminum in China is the first in the stable world in 2001, and the discharge amount of overhaul slag is huge. The overhaul slag contains inorganic fluoride and cyanide which are toxic substances exceeding the standard, has extremely great harm to the environment, is listed in the national hazardous waste directory, and needs to be utilized and treated urgently, and is indistinct. However, the existing overhaul slag recovery system improves the recovery purity of fluoride by repeated water washing, wastes water and generates wastewater which is liable to cause secondary pollution.
In view of this, the embodiment of the application provides a recovery method and a recovery system for aluminum electrolysis overhaul slag, which can improve the recovery rate and recovery purity of fluoride, save water and avoid secondary pollution.
Fig. 1 is a schematic flow chart of a method for recovering aluminum electrolysis overhaul slag according to an embodiment of the present application. As shown in fig. 1, the method for recovering aluminum electrolysis overhaul slag provided in the embodiment of the application includes:
s100: and (3) leaching the aluminum electrolysis overhaul slag at least once and carrying out solid-liquid separation at least once by using the leaching solution. The leaching can be realized by using a stirring tank, the easily soluble substances in the aluminum electrolysis overhaul slag, such as cyanide and fluoride, can be dissolved, the cyanide removal effect can be realized, and the cyanide removal agent can comprise hydrogen peroxide and the like. The solid-liquid separation can be achieved by using a filter, and the embodiments of the present application are not particularly limited. The leaching solution obtained by at least one solid-liquid separation can be repeatedly used in leaching, and leaching residues obtained by the solid-liquid separation can be used for subsequent treatment. The leaching solution can be clear water for dissolving harmful substances in the aluminum electrolysis overhaul slag, such as fluoride and cyanide, and can also comprise other leaching agents, such as a cyanide remover and the like, and can be set according to the specific substances to be dissolved, and the embodiment of the application is not particularly limited.
S200: recycling leaching solution obtained by solid-liquid separation. The leaching solution obtained by solid-liquid separation can be circulated by using the circulating water tank, so that new water does not need to be repeatedly added, and water can be saved.
According to the recycling method of the aluminum electrolysis overhaul slag, at least one leaching and at least one solid-liquid separation are carried out on the aluminum electrolysis overhaul slag, harmful substances such as cyanide and the like can be removed after soluble substances in the aluminum electrolysis overhaul slag are dissolved, the leaching liquid obtained through solid-liquid separation can be used for subsequent treatment to obtain solid-phase fluoride, the purity and the recovery rate of the fluoride are improved, the leaching liquid is recycled, new water can be not required to be repeatedly added, water can be saved, and secondary pollution cannot be caused.
In some embodiments, prior to step S100, further comprising:
classifying the aluminum electrolysis overhaul slag to obtain a waste cathode and a waste refractory material respectively. Because of the higher carbon content in the spent cathode, after fluoride extraction, the final product can be used to prepare graphitized products. After fluoride is extracted from the waste refractory materials, the waste refractory materials are used for preparing building material related materials, and the aluminum electrolysis overhaul slag is reasonably utilized by classification, so that the resource waste is reduced.
And respectively preparing the waste cathode and the waste refractory material into powder to obtain waste cathode powder and waste refractory material powder. The powder is more convenient for the leaching process, improves the leaching efficiency and shortens the leaching time. The waste cathode powder and the waste refractory powder are treated separately.
In some embodiments, step S100 may include:
and (3) carrying out primary leaching on the aluminum electrolysis overhaul slag by using leaching solution, controlling the solid-to-liquid ratio to be in the range of 1:1-1:5, and controlling the leaching time to be in the range of 15-60min so as to dissolve cyanide and fluoride in the aluminum electrolysis overhaul slag, wherein the leaching solution comprises water and the cyanide remover comprises hydrogen peroxide. The solid-to-liquid ratio of the primary leaching may be 1:1, 1:2, 1:3, 1:4 or 1:5, and may be set according to the concentration of the leaching solution, the granularity of the aluminum electrolysis overhaul slag, and the like, and the embodiment of the application is not particularly limited. The leaching time can be controlled to be 60min, 50min, 40min, 30min or 15min, can be specifically limited according to the solid-liquid ratio and the like, and can be controlled by controlling the outflow speed of the solid-liquid mixed product. Hydrogen peroxide reacts primarily with cyanide for cyanide removal and sodium fluoride dissolves in the liquid.
And (3) carrying out solid-liquid separation on the solid-liquid mixed product after primary leaching. After primary leaching, the solid-liquid separation is carried out correspondingly, and the leaching solution after the solid-liquid separation can be recycled.
And (3) carrying out secondary leaching on leaching residues obtained by solid-liquid separation after primary leaching, and controlling the solid-liquid ratio to be in the range of 1:1-1:5, wherein the leaching time is in the range of 15-60min so as to continuously dissolve cyanide and fluoride in the leaching residues. The solid-to-liquid ratio of the secondary leaching may be 1:1, 1:2, 1:3, 1:4 or 1:5, and may be set according to the concentration of the leaching solution, the granularity of the aluminum electrolysis overhaul slag, and the like, and the embodiment of the application is not particularly limited. The leaching time can be controlled at 60min, 50min, 40min, 30min or 15min.
And carrying out solid-liquid separation on the solid-liquid mixed product after the secondary leaching. The secondary leaching corresponds to the secondary solid-liquid separation.
And recycling the leaching solution obtained by solid-liquid separation after the secondary leaching in the primary leaching process.
According to the recycling method of the aluminum electrolysis overhaul slag, fluoride in the aluminum electrolysis overhaul slag is subjected to continuous leaching twice, the obtained leaching liquid is directly evaporated to obtain a sodium fluoride product, a fluoride salt product conversion agent is not needed, repeated water washing of the product is not needed, the recycled sodium fluoride product is high in value, and meanwhile, the leaching slag is subjected to further fluorine fixing, so that the national standard requirement is met. The whole technical process is short, the efficiency is high, the cost is low, and no secondary pollutant is generated.
In some embodiments, step S100 further comprises:
further curing fluoride in leaching residues obtained after secondary leaching by using a curing agent, and controlling the solid-liquid ratio to be in the range of 1:2-1:4, wherein the curing time is in the range of 15-60min; the solidifying agent may include calcium chloride or calcium sulfate.
Carrying out solid-liquid separation on the further solidified leaching slag to obtain fluorine-fixing slag; the fluorine-fixing slag corresponding to the waste cathode can be used for preparing graphitized products, and the fluorine-fixing slag corresponding to the waste refractory material can be used for preparing building materials.
The liquid obtained by solid-liquid separation of the leaching residue after further solidification is recycled to the further solidification of fluoride, and the liquid recycling in the step can be realized through a circulating water tank.
In some embodiments, recycling the leaching solution obtained by solid-liquid separation includes:
and circulating the leaching solution obtained by solid-liquid separation after primary leaching to obtain circulating liquid. This step can be implemented using a circulating water pond.
The circulating liquid is subjected to crystallization treatment in the case where the total dissolved solids of the circulating liquid is higher than 25 g/L.
And controlling the circulating liquid to be recycled in the secondary leaching under the condition that the total dissolved solids of the circulating liquid is 25g/L or less than 25 g/L. Namely, the leaching solution obtained by solid-liquid separation after secondary leaching is recycled in the primary leaching process, and the leaching solution obtained by solid-liquid separation after primary leaching is recycled through a circulating water tank, so that repeated addition of new water is not needed, water can be saved, and secondary pollution is not caused.
In some embodiments, where the total dissolved solids of the circulating liquid is greater than 25g/L, the crystallizing treatment of the circulating liquid comprises:
the circulating liquid is purified and filtered under the condition that the total dissolved solids of the circulating liquid is higher than 25 g/L. Some solid impurities and impurity ions can be filtered out.
And crystallizing the filtered slag to obtain sodium fluoride crystals. The crystallization treatment may be a crystallization process of an evaporation process, and may be a thickening crystallization or a thermal crystallization.
Washing the sodium fluoride crystals. The crystallized particles are discharged after surface washing.
And drying the washed sodium fluoride crystals. Drying may be performed using a dryer.
Extracting lithium fluoride in the concentrated solution obtained after crystallization treatment, wherein the concentrated solution mainly comprises lithium fluoride and sodium carbonate, introducing hydrogen fluoride gas into the concentrated solution to recover lithium fluoride product, and simultaneously converting the sodium carbonate into sodium fluoride. The collected sodium fluoride and lithium fluoride are reused, so that the resource can be reused, the resource waste is avoided, and the secondary pollution problem of discharged products can be avoided.
In a second aspect of the embodiments of the present application, a recovery system of aluminum electrolysis overhaul slag is provided, and fig. 2 is a schematic structural block diagram of the recovery system of aluminum electrolysis overhaul slag provided in the embodiments of the present application. As shown in fig. 2, the recovery system of aluminum electrolysis overhaul slag provided in the embodiment of the present application, using the recovery method as described in the first aspect, includes: the primary recovery subsystem 300 comprises at least one stirring tank and at least one filter, wherein the stirring tank is used for carrying out solid-liquid mixing on the aluminum electrolysis overhaul slag and the leaching solution, and the filter is used for carrying out solid-liquid separation; the secondary recovery subsystem 400 comprises a first circulating water tank, an inlet of the first circulating water tank is communicated with the at least one filter, and an outlet of the first circulating water tank is communicated with the at least one stirring tank. The leaching solution obtained by solid-liquid separation can be circulated by using the circulating water tank, so that new water does not need to be repeatedly added, and water can be saved. The cyclic utilization of leaching solution can be realized between stirred tank and the filter, and the recycling of leaching solution can be realized to first circulating water pond.
According to the recovery system for the aluminum electrolysis overhaul slag, at least one leaching and at least one solid-liquid separation are carried out on the aluminum electrolysis overhaul slag, harmful substances such as cyanogen and the like can be removed after soluble substances in the aluminum electrolysis overhaul slag are dissolved, the leaching liquid obtained through the solid-liquid separation can be used for obtaining solid-phase fluoride through subsequent treatment, the purity and the recovery rate of the fluoride are improved, the leaching liquid is recycled, new water can be not required to be repeatedly added, water can be saved, and secondary pollution cannot be caused.
In some embodiments, fig. 3 is a schematic block diagram of another recovery system for aluminum electrolysis overhaul slag provided in the examples of the present application. As shown in fig. 3, the primary recovery subsystem 300 includes a first agitation tank 301, a second agitation tank 303, a first filter 302, and a second filter 304, wherein the first filter 302 is used for performing solid-liquid separation on the solid-liquid mixture output from the first agitation tank 301, and the second filter 304 is used for performing solid-liquid separation on the solid-liquid mixture output from the second agitation tank 303. The second stirring tank 303 is further provided with a fresh water inlet, the first stirring tank 301 is communicated with a liquid outlet of the second filter 304, and the first circulating water tank 401 is used for circulating the liquid output by the first filter 302 and then injecting the liquid into the second stirring tank 303. The first circulating water tank 401 is a partition structure, and the first circulating water tank 401 of the partition structure is used for respectively storing circulating liquid and distilled water, and the distilled water is used for leaching in the second stirring tank 303. Illustratively, the first filter 302 may be one of a vertical filter, a flat disc filter, a horizontal belt filter, and a rotary drum filter, and the second filter 304 may be one of a vertical filter, a flat disc filter, a horizontal belt filter, and a rotary drum filter. The water content of the leaching residue after solid-liquid separation is 20% -35%.
According to the recovery system of the aluminum electrolysis overhaul slag, fluoride in the aluminum electrolysis overhaul slag is subjected to continuous leaching twice, the obtained leaching liquid is directly evaporated to obtain a sodium fluoride product, a fluoride salt product conversion agent is not needed, repeated water washing of the product is not needed, the recovered sodium fluoride product is high in value, and meanwhile, fluoride is further fixed to the leaching slag, so that the national standard requirement is met. The whole technical process is short, the efficiency is high, the cost is low, and no secondary pollutant is generated.
In some embodiments, the first-stage recovery subsystem 300 further includes a defluorination reaction bin 305, a solid-liquid separator 306 and a second circulating water tank 307, the defluorination reaction bin 305 is respectively communicated with the solid-liquid separator 306 and the second filter 304, the second circulating water tank 307 is respectively communicated with the defluorination reaction bin 305 and the solid-liquid separator 306, the solid-liquid separator 306 is used for carrying out solid-liquid separation on solid-liquid mixed products in the defluorination reaction bin 305 to obtain solid fluorine residues, and the filtrate flows back to the second circulating water tank 307.
In some embodiments, the secondary recovery subsystem 400 further comprises: a filter purifier 402 for purifying and filtering the liquid in the first circulation tank 401; an evaporator 403 for evaporating and crystallizing the filtrate obtained by the purification and filtration of the filter purifier 402 to obtain sodium fluoride crystals; the evaporator can be made of 410S martensitic stainless steel, 430 martensitic stainless steel, 304L austenitic stainless steel, 316L austenitic stainless steel, 2205 duplex stainless steel or 2507 duplex stainless steel. The crystallization process in the evaporation process can be thickening crystallization or thermal crystallization, and the crystallized particles are discharged after surface washing. A scrubber 404 for scrubbing the sodium fluoride crystals; a dryer 406 for drying the washed sodium fluoride crystals; and a lithium extraction reaction bin 405 for extracting lithium fluoride from the concentrated solution in the evaporator 403.
Illustratively, with continued reference to fig. 3, the aluminum electrolysis overhaul slag is classified into a waste cathode and a waste refractory, and crushed into powder respectively. Continuously adding powder into a first stirring tank 301 through a chute, adding hydrogen peroxide and leaching solution (fresh water and secondary leaching solution) into the first stirring tank 301, controlling the solid-liquid ratio to be 1:1, performing primary leaching for removing cyanide and fluoride salt, and controlling the outflow speed of a solid-liquid mixed product to ensure that the solid-liquid mixed product stays in the first stirring tank 301 for 60min. Continuously discharging at the bottom of the first stirring tank 301, feeding the first filtering machine 302 for solid-liquid separation, enabling primary leaching solution to flow into a circulating water tank, conveying primary leaching residues (with the water content of 30%) to the second stirring tank 303 through a conveyor, adding leaching solution, namely circulating water tank liquid with fresh water and TDS (total dissolved solids) lower than 25g/L, into the second stirring tank 303, controlling the solid-liquid ratio to be 1:5, and controlling the outflow speed of a solid-liquid mixed product to ensure that the solid-liquid mixed product stays in the second stirring tank 303 for 15min. The continuous discharging at the bottom of the second stirring tank is subjected to solid-liquid separation through a second filter 304, the secondary leaching solution is added into the first stirring tank 301, and the secondary leaching residue (the water content of 35%) is conveyed to a defluorination reaction bin 305 through a conveyor. Calcium chloride is added into the defluorination reaction bin 305, the solid-liquid ratio is 1:2, the reaction time is 15min, the mixture enters the solid-liquid separator 306 after the reaction, the filtrate flows into the second circulating water tank 307 for recycling, the solid fluorine slag is classified and recycled, the graphitized product is prepared from the waste cathode solid fluorine slag, and the building material is prepared from the waste refractory material solid fluorine slag. The circulating liquid with total dissolved solids greater than 25g/L in the first circulating water tank 401 is filtered by a filter purifier 402 and then enters an evaporator 403, the evaporator 403 is made of 410S or 430 martensitic stainless steel, a thermal crystallization process is adopted, sodium fluoride crystals obtained by a scrubber 404 are dried by a dryer 406, a sodium fluoride product meets the sodium fluoride (YS/T517-2009) standard, concentrated solution is added into a lithium extraction reaction bin 405, hydrogen fluoride gas is introduced to recover lithium fluoride product, and sodium carbonate in the concentrated solution is converted into sodium fluoride.
While preferred embodiments of the present description have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. It is therefore intended that the following claims be interpreted as including the preferred embodiments and all such alterations and modifications as fall within the scope of the disclosure.
It will be apparent to those skilled in the art that various modifications and variations can be made in the present specification without departing from the spirit or scope of the specification. Thus, if such modifications and variations of the present specification fall within the scope of the claims and the equivalents thereof, the present specification is also intended to include such modifications and variations.
Claims (6)
1. The method for recycling the aluminum electrolysis overhaul slag is characterized by comprising the following steps of:
carrying out at least one leaching and at least one solid-liquid separation on the aluminum electrolysis overhaul slag by using leaching liquid;
recycling leaching solution obtained by solid-liquid separation;
the method for leaching and separating solid from liquid at least once for aluminum electrolysis overhaul slag by using leaching solution comprises the following steps:
performing primary leaching on the aluminum electrolysis overhaul slag by using the leaching solution, controlling the solid-to-liquid ratio to be in the range of 1:1-1:5, and controlling the leaching time to be in the range of 15-60min so as to dissolve cyanide and fluoride in the aluminum electrolysis overhaul slag and remove the cyanide by using a cyanide remover, wherein the cyanide remover comprises hydrogen peroxide;
carrying out solid-liquid separation on the solid-liquid mixed product after primary leaching;
performing secondary leaching on leaching slag obtained by solid-liquid separation after primary leaching, and controlling the solid-liquid ratio to be in the range of 1:1-1:5, wherein the leaching time is in the range of 15-60min so as to continuously dissolve fluoride in the leaching slag;
carrying out solid-liquid separation on the solid-liquid mixed product after the secondary leaching;
recycling leaching solution obtained by solid-liquid separation after the secondary leaching in the primary leaching process;
further curing fluoride in the leaching residue obtained after the secondary leaching by using a curing agent, and controlling the solid-liquid ratio to be in the range of 1:2-1:4, wherein the curing time is in the range of 15-60min;
carrying out solid-liquid separation on the further solidified leaching slag to obtain fluorine-fixing slag;
and recycling the liquid obtained by solid-liquid separation of the leaching residues which are further solidified to the further solidification of the fluoride.
2. The method for recycling aluminum electrolysis overhaul slag according to claim 1, wherein before the aluminum electrolysis overhaul slag is subjected to at least one leaching and at least one solid-liquid separation by using leaching solution, the method further comprises:
classifying the aluminum electrolysis overhaul slag to obtain a waste cathode and a waste refractory material respectively;
and respectively preparing the waste cathode and the waste refractory material into powder to obtain waste cathode powder and waste refractory material powder.
3. The method for recycling aluminum electrolysis overhaul slag according to claim 1, wherein the recycling of the leaching solution obtained by the solid-liquid separation comprises:
circulating the leaching solution obtained by solid-liquid separation after the primary leaching to obtain circulating liquid;
crystallizing the circulating liquid under the condition that the total dissolved solids of the circulating liquid is higher than 25 g/L;
and controlling the circulating liquid to be recycled in the secondary leaching under the condition that the total dissolved solids of the circulating liquid is 25g/L or less than 25 g/L.
4. The method for recovering aluminum electrolytic overhaul slag as recited in claim 3, wherein the crystallizing the circulating liquid in a case where the total dissolved solids of the circulating liquid is higher than 25g/L comprises:
purifying and filtering the circulating liquid under the condition that the total dissolved solids of the circulating liquid is higher than 25 g/L;
crystallizing the filtrate obtained by purifying and filtering to obtain sodium fluoride crystals;
washing the sodium fluoride crystals;
drying the washed sodium fluoride crystals;
extracting lithium fluoride from the concentrated solution obtained after crystallization.
5. A recycling system of aluminum electrolysis overhaul slag, characterized by using the recycling method of aluminum electrolysis overhaul slag as claimed in any one of claims 1 to 4, comprising:
the primary recovery subsystem comprises at least one stirring tank and at least one filter, wherein the stirring tank is used for carrying out solid-liquid mixing on aluminum electrolysis overhaul slag and leaching solution, and the filter is used for solid-liquid separation;
the second-stage recovery subsystem comprises a first circulating water tank, an inlet of the first circulating water tank is communicated with at least one filter, and an outlet of the first circulating water tank is communicated with at least one stirring tank;
the first-stage recovery subsystem comprises a first stirring tank, a second stirring tank, a first filter and a second filter, wherein the first filter is used for carrying out solid-liquid separation on the solid-liquid mixed product output by the first stirring tank, and the second filter is used for carrying out solid-liquid separation on the solid-liquid mixed product output by the second stirring tank;
the first stirring tank is communicated with a liquid outlet of the second filter, and the first circulating water tank is used for injecting the liquid output by the first filter into the second stirring tank after circulating;
the first circulating water tank is of a separation structure and is used for storing circulating liquid and distilled water respectively;
the first-stage recovery subsystem further comprises a fluorine removal reaction bin, a solid-liquid separator and a second circulating water tank, wherein the fluorine removal reaction bin is respectively communicated with the solid-liquid separator and the second filter, the second circulating water tank is respectively communicated with the fluorine removal reaction bin and the solid-liquid separator, and the solid-liquid separator is used for obtaining fluorine-fixing slag.
6. The aluminum electrolysis overhaul slag recovery system of claim 5, wherein the secondary recovery subsystem further comprises:
the filtering purifier is used for purifying and filtering the liquid in the first circulating water tank;
the evaporator is used for evaporating and crystallizing the liquid obtained by filtering by the filtering purifier to obtain sodium fluoride crystals;
a scrubber for scrubbing the sodium fluoride crystals;
the dryer is used for drying the washed sodium fluoride crystals;
and the lithium extraction reaction bin is used for extracting lithium fluoride in the concentrated solution in the evaporator.
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| CN115959689B (en) * | 2022-12-28 | 2024-03-22 | 云南云铝润鑫铝业有限公司 | Method for enriching and extracting lithium salt from overhaul slag and carbon slag |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105923643A (en) * | 2016-04-12 | 2016-09-07 | 郑州鸿跃环保科技有限公司 | Method and system of recycling calcium fluoride from aluminium electrolysis cell overhaul slag |
| CN109332352A (en) * | 2018-09-17 | 2019-02-15 | 新疆生产建设兵团第八师天山铝业股份有限公司 | A kind of curing method of electrolytic aluminium slag from delining soluble fluorine |
| CN109437271A (en) * | 2018-12-10 | 2019-03-08 | 湖南绿脉环保科技有限公司 | A method of recycling electrolytic aluminium fluorine-containing resource |
| CN110284157A (en) * | 2019-07-01 | 2019-09-27 | 北京科技大学 | A kind of anode breeze and aluminium electrolyte recoverying and utilizing method |
| CN110357126A (en) * | 2019-08-23 | 2019-10-22 | 中国恩菲工程技术有限公司 | The recovery method of fluorine-containing molten-salt electrolysis slag |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2947675B2 (en) * | 1992-09-08 | 1999-09-13 | オルガノ株式会社 | Method for treating wastewater containing fluorine ions and hydrogen peroxide |
-
2022
- 2022-03-01 CN CN202210211645.4A patent/CN114634189B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105923643A (en) * | 2016-04-12 | 2016-09-07 | 郑州鸿跃环保科技有限公司 | Method and system of recycling calcium fluoride from aluminium electrolysis cell overhaul slag |
| CN109332352A (en) * | 2018-09-17 | 2019-02-15 | 新疆生产建设兵团第八师天山铝业股份有限公司 | A kind of curing method of electrolytic aluminium slag from delining soluble fluorine |
| CN109437271A (en) * | 2018-12-10 | 2019-03-08 | 湖南绿脉环保科技有限公司 | A method of recycling electrolytic aluminium fluorine-containing resource |
| CN110284157A (en) * | 2019-07-01 | 2019-09-27 | 北京科技大学 | A kind of anode breeze and aluminium electrolyte recoverying and utilizing method |
| CN110357126A (en) * | 2019-08-23 | 2019-10-22 | 中国恩菲工程技术有限公司 | The recovery method of fluorine-containing molten-salt electrolysis slag |
Non-Patent Citations (3)
| Title |
|---|
| 曲胜利.《黄金冶金新技术》.冶金工业出版社,2018,第272页第1-2段. * |
| 杜婷婷等.铝电解大修渣处置技术探讨.《世界有色金属》.2020,(第1期),第14-15页. * |
| 铝电解大修渣处置技术探讨;杜婷婷等;《世界有色金属》(第1期);第14-15页 * |
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