CN113430578A - Sodium and lithium removing device and method for aluminum electrolysis electrolyte - Google Patents
Sodium and lithium removing device and method for aluminum electrolysis electrolyte Download PDFInfo
- Publication number
- CN113430578A CN113430578A CN202110800389.8A CN202110800389A CN113430578A CN 113430578 A CN113430578 A CN 113430578A CN 202110800389 A CN202110800389 A CN 202110800389A CN 113430578 A CN113430578 A CN 113430578A
- Authority
- CN
- China
- Prior art keywords
- electrophoresis
- cathode
- anode
- metal crucible
- lithium
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
- C25C3/00—Electrolytic production, recovery or refining of metals by electrolysis of melts
- C25C3/06—Electrolytic production, recovery or refining of metals by electrolysis of melts of aluminium
- C25C3/18—Electrolytes
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B7/00—Electrophoretic production of compounds or non-metals
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Molecular Biology (AREA)
- Electrolytic Production Of Metals (AREA)
Abstract
The invention relates to a sodium and lithium removing device and method for an aluminum electrolyte; the device comprises a heating pipe, an anode guide rod, a heat-preservation cover plate, an electrophoresis cathode, an electrophoresis anode, a high-aluminum refractory corrosion-resistant pouring material, a metal crucible and an extraction device; a heat-insulating cover plate is arranged above the metal crucible, an accommodating space is formed between the metal crucible and the heat-insulating cover plate, and an electrophoresis anode and a cathode are arranged in the formed accommodating space; meanwhile, an opening communicated with the outside is also arranged between the metal crucible and the heat-insulating cover plate, an extraction device is arranged at the opening, and lithium salt and sodium salt enriched around the electrophoresis cathode are extracted through the opening; the heating pipe is arranged inside or on the side wall of the metal crucible; the high-alumina refractory corrosion-resistant castable is arranged at the gas-solid-liquid three-phase interface of the side walls at the two ends of the opening of the metal crucible. The method provided by the invention directly adopts an electrophoresis mode to enrich and extract lithium salt and sodium salt from the molten salt without a wet treatment method, is simple and environment-friendly, and the extracted lithium salt can be used as a raw material for producing the lithium ion battery.
Description
Technical Field
The invention belongs to the technical field of aluminum electrolysis, and particularly relates to extraction of sodium salt and lithium salt from an aluminum electrolyte solution.
Background
High-temperature (800-3Or NaF-KF-AlF3The system is used as a solvent to dissolve alumina (Al)2O3) Forming electrolyte, and allowing direct current to pass through anode (which may be consumable carbon anode or non-carbon inert anode with low consumption), electrolyte, and cathode (which may be aluminum liquid or inert cathode) to form CO at anode2(for carbon anodes) orO2(for non-carbon inert anodes) aluminum is extracted at the cathode by deposition. However, since alumina is refined from bauxite by leaching purification with a caustic soda (NaOH) solution, the alumina inevitably contains residual Na2O (content: about 0.5%) and Na2The accumulation of O in the electrolyte consumes fluoride salts,
3Na2O+2AlF3＝Al2O3+6NaF
therefore, in order to maintain a stable electrolyte molecular ratio (i.e., NaF/AlF) during aluminum electrolysis3Molar ratio) to continuously supplement aluminum fluoride (10-30 kg of aluminum fluoride is consumed per ton of aluminum) with higher cost. In addition, bauxite in Henan, Shanxi, China, etc. contains lithium salt, resulting in alumina containing trace amount of Li2O, the lithium is converted into lithium fluoride (LiF) in the electrolyte and gradually accumulated in the electrolyte, the lithium fluoride in the electrolyte of an electrolytic aluminum plant using alumina in Henan, Shanxi and the like can reach more than 6 percent at most, and the lithium salt is too much, so that the solubility of the alumina is influenced, and the quality of aluminum liquid is influenced; on the other hand, lithium salt is an important raw material of lithium ion batteries widely used in the modern society, and has high added value. Thus, there is a need for an economical extraction of Na salts and lithium salts from aluminum electrolytes, which is the object of the present invention.
Disclosure of Invention
Aiming at the problems in the prior art, the invention aims to solve one of the problems, and provides a sodium and lithium removing device and a method for an aluminum electrolyte, lithium salt and sodium salt are directly enriched and extracted from molten salt in an electrophoresis mode without a wet method, redundant sodium salt and lithium salt in the aluminum electrolyte are removed, the extracted lithium salt can be used as a raw material for producing a lithium ion battery, and the electrolyte after sodium and lithium removal can be directly returned to an aluminum electrolytic cell without additional treatment.
In order to achieve the above object, the present invention firstly provides an aluminum electrolytic electrolyte sodium and lithium removing device;
an aluminum electrolysis electrolyte sodium and lithium removing device comprises a heating pipe, an anode guide rod, a heat preservation cover plate, an electrophoresis cathode, an electrophoresis anode, a high-aluminum refractory corrosion-resistant castable, a metal crucible and an extraction device;
the metal crucible is internally provided with an accommodating space with an upper opening for storing molten salt electrolyte; the high-alumina refractory corrosion-resistant castable is arranged at the gas-solid-liquid three-phase interface of the side walls at the two ends of the opening and used for protecting the material of the metal crucible from being oxidized by air;
a heat-insulating cover plate is arranged above the metal crucible, and an accommodating space is formed between the metal crucible and the heat-insulating cover plate; an electrophoresis anode and an electrophoresis cathode are arranged in an accommodating space formed between the metal crucible and the heat-insulating cover plate;
a heating pipe is arranged inside or on the side wall of the metal crucible; one end of the electrophoresis anode is connected with an anode guide rod;
an opening communicated with the outside is also arranged between the metal crucible and the heat-insulating cover plate; the extraction device extracts lithium salts and sodium salts enriched around the electrophoresis cathode through the opening.
Preferably, the electrophoresis anode and the electrophoresis cathode are arranged in parallel and are separated by 5-50 cm.
Preferably, the opening is formed in the heat-insulating cover plate and marked as a through hole A; the right lower part of the through hole A corresponds to the electrophoresis cathode, namely the through hole A and the electrophoresis cathode are in the same straight line.
Preferably, the extraction means comprises a straw or plate-like extraction structure; can enter the metal crucible through the through hole A and is used for extracting lithium salt and sodium salt enriched by the electrophoresis cathode.
Preferably, the electrophoretic cathode can be replaced by an electrophoretic cathode mesh; the metal crucible can be made of graphite; the electrophoresis cathode and the electrophoresis anode are made of any one of graphite, 310S stainless steel, Fe-Cr-Al alloy, NiAl alloy or oxidation-resistant nickel matrix high-temperature alloy; the high-alumina refractory corrosion-resistant castable comprises high-alumina cement.
The working method of the aluminum electrolysis electrolyte sodium and lithium removing device comprises the following specific steps:
firstly, the molten salt electrolyte is extracted from the electrolytic bath and poured into a metal crucible of the sodium-removing and lithium-removing device, the distance between the electrophoresis anode and the electrophoresis cathode is controlled, and the electrolyte is arranged between the electrophoresis anode and the electrophoresis cathodeApplying a certain voltage; under the action of DC electric field, the electrolyte is made of univalent positive ions Li+、Na+Will migrate preferentially to the electrophoretic cathode over other cations and thus electrophoretically concentrate around the electrophoretic cathode, causing (LiF + NaF)/AlF around the cathode3The molecular ratio is higher than that of bulk molten salt in electrolyte, so that enriched LiF and NaF can be treated with Li3AlF6/Na3AlF6The form is extracted, and the extraction of lithium salt and sodium salt in the molten salt is realized.
Preferably, the distance between the electrophoresis anode and the electrophoresis cathode is 10-30 cm; the voltage of the electrophoresis anode and the electrophoresis cathode is 2V-60V.
Preferably, the invention provides another aluminum electrolytic solution sodium and lithium removing device, the electrophoresis cathode can be replaced by a cathode turntable; the extraction device is a scraper conveyor belt, the electrophoresis anode is removed, the metal crucible is used as the electrophoresis anode, and one end of the metal crucible is connected with the anode guide rod;
an electrophoresis cathode turntable is arranged in a containing space formed between the metal crucible and the heat-insulating cover plate, and the electrophoresis cathode turntable is contacted with a molten salt electrolyte in the metal crucible to ensure that lithium salt and sodium salt are enriched and solidified on the surface of the electrophoresis cathode turntable;
the electrophoresis cathode turntable is connected with the first driving device and drives the electrophoresis cathode turntable to rotate;
a scraper conveyor belt is arranged at an opening between the metal crucible and the heat-insulating cover plate; the scraper conveyer belt is provided with a scraper which is in contact with the electrophoresis cathode turntable and is used for scraping lithium salt and sodium salt solidified on the surface of the electrophoresis cathode turntable onto the scraper conveyer belt and conveying the lithium salt and the sodium salt to the collecting device;
the scraper conveyor belt is connected with the second driving device and is used for driving the scraper conveyor belt to run;
the device comprises the following specific working steps:
firstly, extracting molten salt electrolyte from an electrolytic bath and pouring the molten salt electrolyte into a metal crucible of a sodium-removing and lithium-removing device, controlling the distance between an electrophoresis cathode turntable and an anode by taking the metal crucible as the anode, and applying certain electricity between the electrophoresis cathode turntable and the anodeUnder the action of DC electric field, monovalent cations Li + and Na + will migrate to the cathode preferentially to other cations and accumulate electrophoretically on the surface of the cathode turntable to cause (LiF + NaF)/AlF around the cathode3A bulk molten salt having a higher molecular ratio than in the electrolyte; rotating the cathode turntable, starting a scraper conveyor belt to scrape the lithium salt and the sodium salt enriched on the surface of the electrophoresis cathode turntable off the scraper conveyor belt, and conveying the lithium salt and the sodium salt to a collecting device through the conveyor belt to realize extraction of the lithium salt and the sodium salt in the molten salt; the distance between the anode and the electrophoresis cathode turntable is 5-50 cm; the voltage of the anode and the electrophoretic cathode turntable is 2V-60V.
Has the advantages that:
the device is simple and easy to operate, lithium salt and sodium salt are directly enriched and extracted from the molten salt in an electrophoresis mode without a wet treatment method, the method is simple, safe and environment-friendly, the extracted lithium salt can be used as a raw material for producing the lithium ion battery, and the electrolyte after sodium removal and lithium removal can be directly returned to the aluminum electrolytic cell without additional treatment.
Drawings
FIG. 1 is a schematic structural diagram of an aluminum electrolytic electrolyte sodium and lithium removal device in example 1;
FIG. 2 is a schematic view of the structure of the sodium and lithium removing apparatus for aluminum electrolysis electrolytes in example 2;
FIG. 3 is a schematic structural view of an aluminum electrolytic electrolyte sodium and lithium removing device in example 3;
reference numerals: 1-heating a tube; 2-anode guide rod; 3-a heat preservation cover plate; 4-an electrophoretic cathode; 5-an electrophoresis anode; 6-high-aluminum refractory corrosion-resistant castable; 7-a metal crucible; 8-an extraction device.
Detailed Description
The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.
In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "axial," "radial," "vertical," "horizontal," "inner," "outer," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the present invention and for simplicity in description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.
In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
The first device comprises: the device comprises a heating pipe 1, an anode guide rod 2, a heat-preservation cover plate 3, an electrophoresis cathode 4, an electrophoresis anode 5, a high-aluminum refractory corrosion-resistant castable 6, a metal crucible 7 and an extraction device 8;
the metal crucible 7 forms an accommodating space with an upper opening inside for storing molten salt electrolyte; the high-alumina refractory corrosion-resistant castable 6 is arranged at the gas-solid-liquid three-phase interface of the side walls at the two ends of the opening and is used for protecting the material of the metal crucible 7 from being oxidized by air;
a heat-insulating cover plate 3 is arranged above the metal crucible 7, and an accommodating space is formed between the metal crucible 7 and the heat-insulating cover plate 3; an electrophoresis anode 5 and an electrophoresis cathode 4 are arranged in a containing space formed between the metal crucible 7 and the heat-insulating cover plate 3;
a heating pipe 1 is arranged inside or on the side wall of the metal crucible 7; one end of the electrophoresis anode 5 is connected with an anode guide rod 2;
an opening communicated with the outside is also arranged between the metal crucible 7 and the heat-insulating cover plate 3; the extraction device 8 extracts the enriched lithium and sodium salts around the electrophoretic cathode 4 through the opening.
The electrophoresis anode 5 and the electrophoresis cathode 4 are arranged in parallel and are separated by 5-50 cm.
The opening is formed in the heat-insulating cover plate 3 and is marked as a through hole A; the position right below the through hole A corresponds to the electrophoresis cathode 4, namely the through hole A and the electrophoresis cathode 4 are in the same straight line.
The extraction device 8 comprises a suction tube or a plate-like extraction structure; can enter the inside of the metal crucible 7 through the through hole a for extracting the lithium salt and the sodium salt enriched in the electrophoresis cathode 4.
The electrophoresis cathode 4 can be replaced by an electrophoresis cathode net; the metal crucible 7 can be replaced by graphite; the electrophoresis cathode and the electrophoresis anode are made of any one of graphite, 310S stainless steel, Fe-Cr-Al alloy, NiAl alloy or oxidation-resistant nickel matrix high-temperature alloy.
The device comprises the following specific steps:
firstly, extracting molten salt electrolyte from an electrolytic bath, pouring the molten salt electrolyte into a metal crucible 7 of a sodium-removing and lithium-removing device, controlling the distance between an electrophoresis anode 5 and an electrophoresis cathode 4, and applying a certain voltage between the electrophoresis anode 5 and the electrophoresis cathode 4; under the action of DC electric field, the electrolyte is made of univalent positive ions Li+、Na+Will migrate preferentially to the electrophoretic cathode 4 over other cations and thus electrophoretically concentrate around the electrophoretic cathode 4, causing (LiF + NaF)/AlF around the cathode3The molecular ratio is higher than that of bulk molten salt in electrolyte, so that enriched LiF and NaF can be treated with Li3AlF6/Na3AlF6The form is extracted, and the extraction of lithium salt and sodium salt in the molten salt is realized.
In the step, the distance between the electrophoresis anode 5 and the electrophoresis cathode 4 is 10-30 cm; the voltage of the electrophoresis anode 5 and the electrophoresis cathode 4 is 2V-60V.
A second device: the electrophoresis cathode 4 can be replaced by a cathode turntable 4; the extraction device 8 is a scraper conveyor belt (8), the electrophoresis anode 5 is removed, the metal crucible 7 is used as the electrophoresis anode, and one end of the metal crucible is connected with the anode guide rod 2;
an electrophoresis cathode turntable 4 is arranged in a containing space formed between the metal crucible 7 and the heat-insulating cover plate 3, and the electrophoresis cathode turntable 4 is contacted with a molten salt electrolyte in the metal crucible 7 to ensure that lithium salt and sodium salt are enriched and solidified on the surface of the electrophoresis cathode turntable 4;
the electrophoresis cathode turntable 4 is connected with a driving device I and drives the electrophoresis cathode turntable 4 to rotate;
a scraper conveyor belt 9 is arranged at an opening between the metal crucible 7 and the heat-insulating cover plate 3; the scraper conveyer belt 9 is provided with a scraper which is in contact with the electrophoresis cathode turntable 4 and is used for scraping lithium salt and sodium salt solidified on the surface of the electrophoresis cathode turntable 4 onto the scraper conveyer belt 9 and conveying the lithium salt and the sodium salt to a collecting device;
the scraper conveyor belt 9 is connected with the second driving device and used for driving the scraper conveyor belt 9 to run.
The device II comprises the following specific steps:
firstly, molten salt electrolyte is extracted from an electrolytic cell and poured into a metal crucible 7 of a sodium and lithium removing device, the metal crucible 7 is simultaneously used as an anode, the distance between an electrophoresis cathode turntable 4 and the anode is controlled, a certain voltage is applied between the electrophoresis cathode turntable 4 and the anode, and univalent cations Li & lt + & gt and Na & lt + & gt can migrate to the cathode in preference to other cations under the action of a direct current electric field, so that the electrolytes are enriched on the surface of the electrophoresis cathode turntable 4 in an electrophoresis mode to cause (LiF & lt + & gt NaF)/AlF & lt + & gt around the cathode3A bulk molten salt having a higher molecular ratio than in the electrolyte; and then the cathode turntable 4 is rotated, the scraper conveyor belt 9 is started to scrape the lithium salt and the sodium salt which are enriched on the surface of the electrophoresis cathode turntable 4 off the scraper conveyor belt 9, and the lithium salt and the sodium salt are conveyed to a collecting device by the conveyor belt, so that the extraction of the lithium salt and the sodium salt in the molten salt is realized.
In the step, the distance between the anode and the electrophoresis cathode turntable 4 is 5-50 cm; the voltage of the anode and the electrophoretic cathode turntable 4 is 2V-60V.
Example 1:
as shown in fig. 1, the apparatus for extracting lithium salt and sodium salt from cathode by electrophoretic enrichment comprises a heating tube 1 for keeping electrolyte in a molten state, an anode guide rod 2, a heat-preservation cover plate 3, an electrophoretic cathode 4 which is an electrophoretic anode 5, a high-aluminum refractory corrosion-resistant castable 6 for protecting a metal crucible from being oxidized by air, a metal crucible 7, a suction tube 8 for extracting lithium salt and sodium salt enriched in cathode;
the metal crucible 7 forms an accommodating space with an upper opening inside for storing molten salt electrolyte; the high-alumina refractory corrosion-resistant castable 6 is arranged at the gas-solid-liquid three-phase interface of the side walls at the two ends of the opening and is used for protecting the material of the metal crucible 7 from being oxidized by air;
a heat-insulating cover plate 3 is arranged above the opening of the metal crucible 7 and used for sealing the metal crucible 7; an accommodating space is formed between the metal crucible 7 and the heat-insulating cover plate 3; an electrophoresis anode 5 and an electrophoresis cathode 4 are arranged in a containing space formed between the metal crucible 7 and the heat-insulating cover plate 3, namely the metal crucible 7, and the electrophoresis anode 5 and the electrophoresis cathode 4 are arranged in parallel at intervals and are vertical to the bottom surface of the metal crucible 7;
a heating pipe 1 is arranged on the side wall of the metal crucible 7; one end of the electrophoresis anode 5 is connected with an anode guide rod 2, and the other end of the anode guide rod 2 penetrates through the heat-insulating cover plate 3;
the heat-insulating cover plate 3 is also provided with a through hole with a cover (the cover is used for opening and sealing the through hole) which is marked as a through hole A; the position right below the through hole A corresponds to the electrophoresis cathode 4, namely the through hole A and the electrophoresis cathode 4 are in the same straight line;
the device further comprises a suction tube 8; the suction tube 8 can enter the inside of the metal crucible 7 through the through hole a for extracting lithium salts and sodium salts enriched in the electrophoresis cathode 4.
The specific method comprises the following steps:
firstly, extracting molten salt electrolyte from an electrolytic bath, pouring the molten salt electrolyte into a metal crucible 7 of a sodium-removing and lithium-removing device, controlling the distance between an electrophoresis anode 5 and an electrophoresis cathode 4 to be 30cm, and applying 15V voltage between the electrophoresis anode 5 and the electrophoresis cathode 4; under the action of DC electric field, the electrolyte has small ionic radius+、Na+Will migrate towards the cathode preferentially to other cations and thus electrophoretically concentrate around electrophoretic cathode 4, causing molecules around the cathodeRatio ((LiF + NaF)/AlF)3) Is higher than the molten salt in the device, so that the suction pipe 8 enters the metal crucible 7 through the through hole A to collect LiF and NaF and Li3AlF6/Na3AlF6And absorbing the form to realize the extraction of lithium salt and sodium salt in the molten salt.
Example 2:
as shown in fig. 2, the apparatus for extracting lithium salt and sodium salt from cathode by electrophoretic enrichment comprises a heating tube 1 for keeping electrolyte in a molten state, an anode guide rod 2, a heat-preservation cover plate 3, an electrophoretic cathode mesh 4 as an electrophoretic anode 5, a high-alumina refractory corrosion-resistant casting 6 for protecting a metal crucible from air oxidation, a metal crucible 7 and a suction tube 8 for extracting lithium salt and sodium salt enriched in cathode;
the metal crucible 7 forms an accommodating space with an upper opening inside for storing molten salt electrolyte; the high-alumina refractory corrosion-resistant castable 6 is arranged at the gas-solid-liquid three-phase interface of the side walls at the two ends of the opening and is used for protecting the material of the metal crucible 7 from being oxidized by air;
a heat-insulating cover plate 3 is arranged above the opening of the metal crucible 7 and used for sealing the metal crucible 7; a heating pipe 1 is arranged on the side wall of the metal crucible 7; an electrophoresis anode 5 and an electrophoresis cathode net 4 are arranged inside the metal crucible 7, and the electrophoresis anode 5 and the electrophoresis cathode net 4 are arranged in parallel and are separated by a certain distance;
one end of the electrophoresis anode 5 is connected with an anode guide rod 2, and the other end of the anode guide rod 2 penetrates through the heat-insulating cover plate 3;
the heat-insulating cover plate 3 is also provided with a through hole with a cover, which is marked as a through hole A (the cover is used for opening and sealing the through hole), and the position right below the through hole A corresponds to the electrophoresis cathode net 4, namely the through hole A and the electrophoresis cathode net 4 are in the same straight line;
the device further comprises a suction tube 8; the pipette 8 can enter the electrophoresis cathode net 4 through the through hole A and is used for extracting enriched lithium salt and sodium salt.
The specific method comprises the following steps:
firstly, molten salt electrolyte is extracted from an electrolytic bath and poured into a metal crucible 7 of a sodium and lithium removing device, the distance between an electrophoresis anode 5 and an electrophoresis cathode 4 is controlled to be 25cm, and the electrophoresis anode5 applying a voltage of 10V between the electrophoresis cathode 4; under the action of DC electric field, the electrolyte has small ionic radius+、Na+Will migrate towards the cathode preferentially to other cations and thus be electrophoretically concentrated in the hollow cathode mesh (4), giving rise to a molecular ratio ((LiF + NaF)/AlF) around the cathode3) Is higher than the molten salt of the body in the device, thereby leading the suction pipe 8 to enter the hollow cathode net (4) through the through hole A to collect LiF and NaF and Li3AlF6/Na3AlF6And absorbing the form to realize the extraction of lithium salt and sodium salt in the molten salt.
Example 3:
as shown in fig. 3, the device for extracting lithium salt and sodium salt from the cathode by electrophoretic enrichment is provided, and the electrophoretic cathode 4 is replaced by a cathode turntable; the extraction device 8 is a scraper conveyor belt; after replacement, the sodium and lithium removing device comprises a heating pipe 1, an anode guide rod 2, a heat-insulating cover plate 3, an electrophoresis cathode turntable 4, a metal crucible 7 (an electrophoresis anode simultaneously), and a scraper conveyor belt 9 for extracting lithium salt and sodium salt enriched in the cathode.
A heat-insulating cover plate 3 is arranged above the metal crucible 7; an accommodating space is formed between the metal crucible 7 and the heat-insulating cover plate 3, an electrophoresis cathode turntable 4 is arranged in the accommodating space, and the electrophoresis cathode turntable 4 is in contact with a molten salt electrolyte in the metal crucible 7 (namely the lowest point of the turntable is lower than the liquid level of the electrolyte solution in the crucible), so that lithium salt and sodium salt are enriched and solidified on the surface of the electrophoresis cathode turntable 4;
the electrophoresis cathode turntable 4 is connected with a driving device I and drives the electrophoresis cathode turntable 4 to rotate;
an opening communicated with the outside is further formed in the containing space formed by the metal crucible 7 and the heat-insulating cover plate 3, a scraper conveying belt 9 is arranged at the opening, a scraper is arranged on the scraper conveying belt 9 and is in contact with the electrophoresis cathode turntable 4, and the scraper conveying belt is used for scraping lithium salt and sodium salt solidified on the surface of the electrophoresis cathode turntable 4 onto the scraper conveying belt 9 and conveying the lithium salt and the sodium salt to a collecting device;
the scraper conveyor belt 9 is connected with a second driving device and is used for driving the scraper conveyor belt 9 to run;
and high-alumina refractory corrosion-resistant castable 6 is arranged at the gas-solid-liquid three-phase interface of the side walls at the two ends of the opening of the metal crucible 7 and is used for protecting the material of the metal crucible 7 from being oxidized by air.
One end of the metal crucible 7 is connected with the anode guide rod 2 and is used as an electrophoresis anode;
a plurality of heating pipes 1 are arranged on the side wall or inside the metal crucible 7;
the specific method comprises the following steps:
firstly, extracting molten salt electrolyte from an electrolytic bath and pouring the molten salt electrolyte into a metal crucible 7 of a sodium and lithium removing device, wherein a heating pipe 1 is used for heating to keep the electrolyte in a liquid state, and an electrophoresis cathode turntable 4 is in contact with the liquid level of the electrolyte; controlling the distance between the electrophoresis cathode turntable 4 and a metal crucible 7 (as an anode) to be 30 cm; meanwhile, the metal crucible 7 is used as an anode, and the voltage applied between the metal crucible and the electrophoresis cathode turntable 4 is 4 v; starting a driving device to drive the electrophoretic cathode turntable 4 to rotate the electrolyte at a constant speed under the action of a direct current electric field, wherein the ion radius of the univalent cation Li is small+、Na+Will migrate towards the cathode in preference to other cations and thus electrophoretically concentrate on the surface of the electrophoretic cathode disk 4, causing a molecular ratio ((LiF + NaF)/AlF) around the cathode3) Higher than the bulk molten salt in the apparatus;
and then, starting the second driving device, driving the scraper conveyor belt 9 to operate, scraping the lithium salt and the sodium salt which are enriched on the surface of the electrophoresis cathode turntable 4 onto the scraper conveyor belt 9, and conveying the lithium salt and the sodium salt to a collecting device through the conveyor belt to realize extraction of the lithium salt and the sodium salt in the molten salt.
Description of the drawings: the above embodiments are only used to illustrate the present invention and do not limit the technical solutions described in the present invention; thus, while the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted; all such modifications and variations are intended to be included herein within the scope of this disclosure and the present invention and protected by the following claims.
Claims (10)
1. An aluminum electrolysis electrolyte sodium and lithium removing device is characterized by comprising a heating pipe (1), an anode guide rod (2), a heat preservation cover plate (3), an electrophoresis cathode (4), an electrophoresis anode (5), a high-aluminum refractory corrosion-resistant castable (6), a metal crucible (7) and an extraction device (8);
the metal crucible (7) forms an accommodating space with an upper opening inside for storing molten salt electrolyte; the high-alumina refractory corrosion-resistant castable (6) is arranged at the gas-solid-liquid three-phase interface of the side walls at the two ends of the opening and is used for protecting the material of the metal crucible (7) from being oxidized by air;
a heat-insulating cover plate (3) is arranged above the metal crucible (7), and an accommodating space is formed between the metal crucible (7) and the heat-insulating cover plate (3); an electrophoresis anode (5) and an electrophoresis cathode (4) are arranged in an accommodating space formed between the metal crucible (7) and the heat-insulating cover plate (3);
a heating pipe (1) is arranged inside or on the side wall of the metal crucible (7); one end of the electrophoresis anode (5) is connected with an anode guide rod (2);
an opening communicated with the outside is also arranged between the metal crucible (7) and the heat-insulating cover plate (3); the extraction device (8) extracts the enriched lithium salt and sodium salt around the electrophoresis cathode (4) through the opening.
2. The aluminum electrolytic solution sodium and lithium removing device according to claim 1, wherein the electrophoresis anode (5) and the electrophoresis cathode (4) are arranged in parallel and separated by 5-50 cm.
3. The aluminum electrolysis electrolyte sodium and lithium removing device according to claim 1, wherein the opening is formed in the heat-insulating cover plate (3) and is marked as a through hole A; the right lower part of the through hole A corresponds to the electrophoresis cathode (4), namely the through hole A and the electrophoresis cathode (4) are in the same straight line.
4. An aluminium electrolysis electrolyte sodium and lithium removal apparatus according to claim 3, wherein the extraction device (8) comprises a suction pipe or a plate-like extraction structure; can enter the inside of the metal crucible (7) through the through hole A and is used for extracting lithium salt and sodium salt enriched by the electrophoresis cathode (4).
5. The aluminum electrolytic sodium and lithium removal device according to claim 1, wherein the electrophoresis cathode (4) is replaced by an electrophoresis cathode mesh; the metal crucible (7) can be replaced by graphite; the electrophoresis cathode and the electrophoresis anode are made of any one of graphite, 310S stainless steel, Fe-Cr-Al alloy, NiAl alloy or oxidation-resistant nickel matrix high-temperature alloy; the high-alumina refractory corrosion-resistant castable comprises high-alumina cement.
6. An aluminium electrolysis electrolyte sodium and lithium removing apparatus according to claim 1, wherein the electrophoresis cathode (4) is replaceable as a cathode turntable (4); the extraction device (8) is a scraper conveyor belt (8), the electrophoresis anode (5) is removed, the metal crucible (7) is used as the electrophoresis anode, and one end of the metal crucible is connected with the anode guide rod (2);
an electrophoresis cathode turntable (4) is arranged in an accommodating space formed between the metal crucible (7) and the heat-insulating cover plate (3), and the electrophoresis cathode turntable (4) is contacted with a molten salt electrolyte in the metal crucible (7) to ensure that lithium salt and sodium salt are enriched and solidified on the surface of the electrophoresis cathode turntable (4);
the electrophoresis cathode turntable (4) is connected with the first driving device and drives the electrophoresis cathode turntable (4) to rotate;
a scraper conveyor belt (8) is arranged at an opening between the metal crucible (7) and the heat-insulating cover plate (3); the scraper conveyor belt (8) is provided with a scraper which is in contact with the electrophoresis cathode turntable (4) and is used for scraping lithium salt and sodium salt solidified on the surface of the electrophoresis cathode turntable (4) onto the scraper conveyor belt (8) and conveying the lithium salt and the sodium salt to a collecting device;
and the scraper conveyor belt (8) is connected with the second driving device and is used for driving the scraper conveyor belt (8) to run.
7. The working method of the aluminum electrolytic electrolyte sodium and lithium removing device according to any one of claims 1 to 5, characterized by comprising the following steps:
firstly, extracting molten salt electrolyte from an electrolytic bath, pouring the molten salt electrolyte into a metal crucible (7) of a sodium-removing and lithium-removing device, controlling the distance between an electrophoresis anode (5) and an electrophoresis cathode (4), and applying a certain voltage between the electrophoresis anode (5) and the electrophoresis cathode (4); under the action of DC electric field, the electrolyte is made of univalent positive ions Li+、Na+Will migrate preferentially to the electrophoretic cathode (4) over other cations and thus electrophoretically concentrate around the electrophoretic cathode (4), causing (LiF + NaF)/AlF around the cathode3The molecular ratio is higher than that of bulk molten salt in electrolyte, so that enriched LiF and NaF can be treated with Li3AlF6/Na3AlF6The form is extracted, and the extraction of lithium salt and sodium salt in the molten salt is realized.
8. Working method according to claim 7, characterized in that the distance between the electrophoresis anode (5) and the electrophoresis cathode (4) is 10-30 cm; the voltage of the electrophoresis anode (5) and the electrophoresis cathode (4) is 2V-60V.
9. The working method of the aluminum electrolytic electrolyte sodium and lithium removing device according to claim 6, characterized by comprising the following steps:
firstly, molten salt electrolyte is extracted from an electrolytic cell and poured into a metal crucible (7) of a sodium and lithium removing device, the metal crucible (7) is simultaneously used as an anode, the distance between an electrophoresis cathode rotating disc (4) and the anode is controlled, a certain voltage is applied between the electrophoresis cathode rotating disc (4) and the anode, and univalent cations Li & lt + & gt and Na & lt + & gt can migrate to the cathode in preference to other cations under the action of a direct current electric field, so that the electrolyte is enriched on the surface of the electrophoresis cathode rotating disc (4) in an electrophoresis mode to cause (LiF & lt + & gt NaF)/AlF & lt + & gt around the cathode3A bulk molten salt having a higher molecular ratio than in the electrolyte; then the cathode turntable (4) is rotated, then the scraper conveyor belt (8) is started to scrape the lithium salt and the sodium salt which are enriched on the surface of the electrophoresis cathode turntable (4) off the scraper conveyor belt (8), and the lithium salt and the sodium salt are conveyed to a collecting device by the conveyor belt,the extraction of lithium salt and sodium salt in the molten salt is realized.
10. Working method according to claim 9, characterized in that the distance between the anode and the rotating disk of electrophoretic cathode (4) is 5-50 cm; the voltage of the anode and the electrophoretic cathode turntable (4) is 2V-60V.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110800389.8A CN113430578B (en) | 2021-07-15 | 2021-07-15 | Sodium and lithium removing device and method for aluminum electrolysis electrolyte |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110800389.8A CN113430578B (en) | 2021-07-15 | 2021-07-15 | Sodium and lithium removing device and method for aluminum electrolysis electrolyte |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113430578A true CN113430578A (en) | 2021-09-24 |
| CN113430578B CN113430578B (en) | 2022-10-04 |
Family
ID=77760575
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110800389.8A Active CN113430578B (en) | 2021-07-15 | 2021-07-15 | Sodium and lithium removing device and method for aluminum electrolysis electrolyte |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113430578B (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4533442A (en) * | 1984-07-31 | 1985-08-06 | Amax Inc. | Lithium metal/alloy recovery from multi-component molten salt |
| US4780186A (en) * | 1987-06-22 | 1988-10-25 | Aluminum Company Of America | Lithium transport cell process |
| US4790917A (en) * | 1986-11-07 | 1988-12-13 | Alcan International Limited | Refining of lithium-containing aluminum scrap |
| CN101400829A (en) * | 2006-03-10 | 2009-04-01 | 株式会社大阪钛技术 | Method of removing/concentrating metal-fog-forming metal present in molten salt, apparatus therefor, and process and apparatus for producing ti or ti alloy with these |
| US20090114546A1 (en) * | 2006-03-10 | 2009-05-07 | Tadashi Ogasawara | Method for Removing/Concentrating Metal-Fog-Forming Metal Present in Molten Salt, Apparatus Thereof, and Process and Apparatus for Producing Ti or Ti Alloy by use of them |
| CN107541753A (en) * | 2017-08-10 | 2018-01-05 | 中国铝业股份有限公司 | A kind of removing method of the Hull cell containing lithium in lithium electrolyte |
| US20200385880A1 (en) * | 2017-11-29 | 2020-12-10 | Korea Institute Of Industrial Technology | Molten salt electrorefining apparatus and refining method |
-
2021
- 2021-07-15 CN CN202110800389.8A patent/CN113430578B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4533442A (en) * | 1984-07-31 | 1985-08-06 | Amax Inc. | Lithium metal/alloy recovery from multi-component molten salt |
| US4790917A (en) * | 1986-11-07 | 1988-12-13 | Alcan International Limited | Refining of lithium-containing aluminum scrap |
| US4780186A (en) * | 1987-06-22 | 1988-10-25 | Aluminum Company Of America | Lithium transport cell process |
| CN101400829A (en) * | 2006-03-10 | 2009-04-01 | 株式会社大阪钛技术 | Method of removing/concentrating metal-fog-forming metal present in molten salt, apparatus therefor, and process and apparatus for producing ti or ti alloy with these |
| US20090114546A1 (en) * | 2006-03-10 | 2009-05-07 | Tadashi Ogasawara | Method for Removing/Concentrating Metal-Fog-Forming Metal Present in Molten Salt, Apparatus Thereof, and Process and Apparatus for Producing Ti or Ti Alloy by use of them |
| CN107541753A (en) * | 2017-08-10 | 2018-01-05 | 中国铝业股份有限公司 | A kind of removing method of the Hull cell containing lithium in lithium electrolyte |
| US20200385880A1 (en) * | 2017-11-29 | 2020-12-10 | Korea Institute Of Industrial Technology | Molten salt electrorefining apparatus and refining method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113430578B (en) | 2022-10-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP1364077B1 (en) | A method and an electrowinning cell for production of metal | |
| CN111549359B (en) | System and method for purifying aluminum | |
| US20190032232A1 (en) | Systems and methods of protecting electrolysis cells | |
| CN203999841U (en) | Electrolyzer, electrolyzer system and electrolyzer assembly | |
| US20160108532A1 (en) | Method and apparatus for liquid metal electrode connection in production or refining of metals | |
| AU2015315310B2 (en) | Systems and methods of protecting electrolysis cell sidewalls | |
| CN113430578B (en) | Sodium and lithium removing device and method for aluminum electrolysis electrolyte | |
| CN211339706U (en) | Automatic discharge scraper lead electrolytic tank | |
| CN112458498A (en) | Electrolytic tank for electrolyzing aluminum and electrolysis process using electrolytic tank | |
| KR20180000944U (en) | Electrowinning device of Indium | |
| CN216192757U (en) | Bolt-free easily-detachable loop type transparent electrolytic tank for sodium hypochlorite generator | |
| CN206799764U (en) | Rare earth molten-salt electrolysis device | |
| CN213680931U (en) | Closed type rare earth chloride system electrolytic cell | |
| CN113930809A (en) | Aluminum electrolysis system suitable for low-lithium aluminum oxide | |
| CN102071434B (en) | Method for removing impurity CaCl2 from lithium electrolyte KCl-LiCl | |
| CN215137764U (en) | Heavy metal purification and separation device for processing sulfuric acid for storage battery | |
| RU2809349C1 (en) | Device for electrochemical refining of aluminium in electrolysers (variants) | |
| RU2710490C1 (en) | Electrolysis cell for producing metals from metal oxides in molten electrolytes | |
| RU2471892C1 (en) | Method of producing metal by molten-salt electrolysis | |
| CN117867600A (en) | Electrolytic tank and method for electrolytic recovery of waste aluminum/waste aluminum alloy |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |