144results about "Aluminium fluorides" patented technology

The invention discloses an efficient preparation process of cryolite, and relates to the field of cryolite preparation. The process comprises the following steps: S1, taking carbon residues ground by a ball mill, and putting the carbon residues into a dissolution reaction kettle filled with alkali liquor for reaction; s2, after the reaction in the reaction kettle is finished, filter pressing is performed through a plate-and-frame filter press, and coarse carbon powder and filtrate are obtained; s3, pumping the filtrate into a carbon reaction kettle, and introducing carbon dioxide for reaction; s4, after the reaction in the carbon component reaction kettle is finished, carrying out filter pressing through a plate-and-frame filter press; and S5, drying the solid material obtained by filter pressing in a calcining furnace to obtain cryolite. In the process, the industrial waste carbon residue is used as a raw material, and participates in a series of reactions to prepare the cryolite after being subjected to ball-milling refining treatment, so that resource recycling of the waste is realized. The method not only effectively reduces the pollution of the carbon residue to the environment, reduces the accumulation amount of solid wastes, but also reduces the exploitation of natural cryolite minerals, and protects non-renewable resources.

The invention discloses a process method for preparing aluminum fluoride by recovering electrolytic aluminum electrolyte, and relates to the technical field of waste material recovery. The invention relates to a process method for preparing aluminum fluoride by recovering electrolytic aluminum electrolyte. The preparation method comprises the following steps: firstly, grinding the carbon residue or electrolyte into powder, wherein the fineness is greater than 150 meshes; adding water into the powder, pulping, and adding a certain amount of aluminum sulfate or aluminum hydroxide; sulfuric acid is added for leaching under the stirring condition, the leaching temperature ranges from 70 DEG C to 100 DEG C, the leaching time ranges from 2 h to 5 h, and the pH of the leaching end point ranges from 1 to 2; adding water to dilute the filtrate, adding caustic soda flakes to adjust the pH value to 12-14 to remove impurities, and filtering out insoluble hydroxides to obtain a mixed salt solution of sodium fluoride and sodium metaaluminate; adding sulfuric acid into the mixed salt solution while stirring to adjust the pH value to 3-6, and reacting at the temperature of 60-100 DEG C for 2-5 hours to obtain aluminum fluoride slurry; and filtering and washing the slurry to obtain aluminum fluoride trihydrate, and calcining at 500-700 DEG C to obtain anhydrous aluminum fluoride with the purity of more than 95%. The method turns waste into wealth, recycles resources, and is short in process flow, low in cost and high in recovery rate.

To provide a liquid dispersion of fluoride particles, the dispersion having excellent dispersibility, being suitable for production of an optical film such as an anti-reflection film, and having a refractive index lower than that of magnesium fluoride, for example; a composition for forming an optical film; and an optical film.SOLUTION: A liquid dispersion of fluoride particles according to the present invention comprises fluoride particles, an anionic surfactant as a dispersing agent for the fluoride particles, and an organic solvent. The fluoride particles contain, in the compositional makeup thereof, at least aluminum and an alkali metal, and an alkaline-earth metal as an arbitrary element, and are dispersed in the organic solvent.SELECTED DRAWING: None

The application provides an energy-saving building material production equipment and an aluminum electrolysis overhaul slag recycling method. The application relates to the field of energy-saving building material production equipment, and the energy-saving building material production equipment comprises a base. The energy-saving building material production equipment provided by the application inputs roasting gas into a drying outer cylinder, drives a drying inner cylinder to rotate and tumble filter residue A through a drying motor, and performs drying, so that energy is effectively saved. The filter residue A after drying is input into a crushing box through a lifting conveyor belt, is crushed by crushing cutters, is sieved, is input into a mixing box through a discharge hopper, is mixed with mixed material, cement and lime to obtain the mixed material, the mixed material is pressed into no-burning bricks by pressing the mixed material into the first mold through an upper pressing die head and a lower pressing die head, meanwhile, the second mold synchronously completes filling to realize continuous production, the filter residue A is converted into the no-burning bricks, waste resource utilization is realized, and environmental pollution is reduced. The double molds work alternately, production is ensured to be uninterrupted, and overall productivity and economic benefits are improved.

The utility model discloses an aluminum fluoride crystal growing device which comprises a crystallizing tank and a stirring part, the stirring part is arranged in the crystallizing tank and provided with a rotating shaft rotationally arranged in the crystallizing tank, a fixed transmission rod is rotationally arranged in the rotating shaft, a supporting frame is fixedly arranged at the top of the crystallizing tank, and the supporting frame is fixedly connected with the crystallizing tank. The bottom of the supporting frame is fixedly connected with the top of the fixed transmission rod, a plurality of stirring rods are rotationally arranged on the outer side of the rotating shaft and meshed with the fixed transmission rod, and the rotating shaft rotates to drive the stirring rods to revolve around the fixed transmission rod so as to drive the stirring rods to rotate. By arranging the crystallizing tank and the stirring part, when aluminum fluoride mother liquor is stirred, the stirring rod rotationally arranged on the side surface of the rotating shaft is driven to revolve around the fixed transmission rod through the rotation of the rotating shaft, so that the fixed transmission rod drives the stirring rod to rotate, and a plurality of stirring centers are formed in the crystallizing tank; and the efficiency of separating out aluminum fluoride crystals from the aluminum fluoride mother liquor is improved.

The application discloses a process for preparing high-molecular-ratio cryolite and ammonium sulfate by using fluorine-containing etching waste liquid, and comprises the following steps: adding sodium metaaluminate slurry and sodium sulfate solution into the fluorine-containing etching waste liquid, then adjusting pH to be acidic by using a sulfuric acid solution, carrying out heating reaction, then carrying out centrifugal separation treatment, and drying the obtained cryolite precipitate; adding sodium metaaluminate slurry into the fluorine-containing supernatant, and obtaining defluorination filtrate by treatment; adding a sulfuric acid solution into the defluorination filtrate, carrying out neutralization reaction, then carrying out vacuum evaporation on the reaction mixture containing ammonium sulfate, carrying out centrifugal separation treatment after cooling, drying the obtained ammonium sulfate precipitate, and obtaining ammonium sulfate product. The fluorine ion in the fluorine-containing etching waste liquid can be effectively utilized, the generated cryolite product can reach the national standard of high-molecular ratio, the fluorine ion content of the generated filtrate is less, so that the filtrate can enter the synthesis of ammonium sulfate, and no waste liquid is generated in the process.

The invention discloses application of fluorine-containing mixed gas in removal of crystal water in fluorinated metal salt, the fluorine-containing mixed gas composed of fluorine gas and nitrogen gas is used as a working atmosphere, and the side reaction between the removed water and the fluorinated metal salt is effectively inhibited through the strong oxidizing property of the fluorine gas. According to the method, the problem of oxidation or hydrolysis easily occurring in the inert atmosphere is avoided, the efficient and stable dehydration process is achieved, the purity, stability and efficiency are remarkably improved, and a reliable solution is provided for industrial application of the fluorinated metal salt.

The present application relates to a method for reducing the content of sulfur in aluminum fluoride, which comprises the following steps: uniformly mixing crude aluminum fluoride powder containing sulfate impurities with ammonium hydrogen fluoride powder to obtain a mixture; placing the mixture in a reactor and performing programmed temperature calcination under a protective atmosphere; discharging the sulfur and fluorine-containing volatile gas generated by calcination after treatment by an absorption system; cooling the calcined material to room temperature; washing the cooled material with water or blowing inert gas to remove residual ammonium salt or dust, and then drying to obtain a low-sulfur aluminum fluoride product. The in-situ HF generated by the decomposition of NH4HF2 is used for gas-solid reaction, which can effectively attack and convert stable sulfate impurities existing in various forms, has high desulfurization efficiency and is deep and thorough; the reaction conditions are mild, the main phase of the product is stable, the process flow is simple, and the energy consumption is low.

[Problem] To provide a powder that comprises a lithium-ion conductive substance functioning as a protective material for a positive electrode active material, that has excellent withstand voltage characteristics, and that exhibits excellent uniformity of adhesion to positive electrode active material particles. [Solution] This fluoride powder contains, as the main ingredient, a lithium-containing metal fluoride including lithium (Li), a metal element M, and fluorine (F), and has a BET diameter d of not more than 300 nm as calculated using formula (1).　(1): d=6×103 / (ρ×S) Here, d represents the BET diameter (nm), ρ represents the true density (g / cm3) of the powder, and S represents the BET specific surface area (m2 / g) of the powder.

The application provides a method for treating and recycling ternary iron-removing aluminum slag and lithium-rich aluminum electrolyte slag, and belongs to the technical field of lithium resource recycling and utilization, and comprises the following steps: preparing an aluminum sulfate solution; pretreating the lithium-rich aluminum electrolyte slag; heating and dissolving; fluorine-aluminum precipitation; evaporation and concentration; alkali impurity removal; and lithium precipitation.The application uses ternary iron-removing aluminum slag as an aluminum source and adopts an aluminum salt leaching process to treat and recycle the lithium-rich aluminum electrolyte slag, thereby solving the problem of large aluminum salt consumption, recycling the ternary iron-removing aluminum slag and the lithium-rich aluminum electrolyte slag, achieving a fluorine resource utilization rate of more than 95%, and achieving a lithium resource recycling rate of more than 96%. The prepared regenerated cryolite and battery-grade lithium carbonate both meet national standards and industry standards.The application has the advantages of simple operation, low cost, green environmental protection, high recycling rate, high social value and considerable economic benefits.

The application discloses a fluorite tailing waste residue production method of aluminum fluoride, and relates to the technical field of aluminum fluoride production processes. The fluorite tailing waste residue production method of aluminum fluoride comprises the following steps: step one, mixing the purified fluorite tailing and concentrated sulfuric acid according to a proportion, and heating and reacting in a rotary kiln to generate hydrogen fluoride gas; and step two, passing the hydrogen fluoride gas into a fluidized bed, and fluidizing and reacting the hydrogen fluoride gas in the fluidized bed in a posture of rotating around an aluminum hydroxide bed layer, and driving the aluminum hydroxide bed layer to tumble under the flow of the hydrogen fluoride gas. Through the driving of a rotating assembly in the fluidized bed, the hydrogen fluoride gas is driven to rotate around the aluminum hydroxide bed layer for fluidization and combination reaction, so that the hydrogen fluoride gas always passes through the aluminum hydroxide bed with uniform thickness, and the hydrogen fluoride gas acts on the uniform tumbling fluidization reaction of the aluminum hydroxide bed layer.

This invention relates to the field of co-processing and resource utilization of fluorine- and silicon-containing solid waste, specifically disclosing a high-quality, tiered resource utilization process for fluorosilicone slag. This process uses fluorosilicone slag as raw material, sequentially undergoing alkali dissolution activation, acidification polymerization, primary defluorination crystallization, secondary deep defluorination, and salt resource recovery steps to produce washed silica, magnesium fluoride, cryolite, and sodium sulfate, while simultaneously achieving mother liquor recycling and wastewater reduction. This invention features a short process flow, closed-loop material circulation between units, and a SiO2 recovery rate of over 95% in the fluorosilicone slag. The silica, magnesium fluoride, cryolite, and sodium sulfate products meet relevant national or industry standards, achieving high-quality, tiered resource utilization and overall wastewater reduction for fluorosilicone slag.

An apparatus for treating a fluid including an organofluorine compound, the apparatus including: a vessel that contains a liquid with a fluoride bonding agent; a combustion chamber in fluid communication with the vessel via an outlet submerged in the liquid; an inlet configured to introduce the fluid into the combustion chamber; and a flame source configured to produce a flame in the combustion chamber to at least partially break down the organofluorine compound to form a gaseous combustion product bearing fluoride, wherein the gaseous combustion product passes from the outlet of the combustion chamber through the liquid so that the fluoride in the gaseous combustion product is at least partially bound by the fluoride bonding agent.

The solid electrolyte material of the present disclosure is a solid electrolyte material containing Li, Al, and F, comprising an amorphous substance containing Li, Al, and F. The solid electrolyte material of the present disclosure may further comprise a crystalline phase containing Li, Al, and F. The solid electrolyte material production method of the present disclosure comprises: (A) synthesizing a compound comprising a crystalline phase containing Li, Al, and F; and (B) performing a treatment to disturb the crystal of the compound. The compound may be mechanochemically treated in the step (B).

The present invention provides a ternary composite material for an all-solid-state battery, including a ternary material and a fast ion conductor of LixMyFx+3y in-situ coated on the surface of the ternary material; the application also provides a preparation method for ternary composite material and its application. On the one hand, the presence of LixMyFx+3y in the ternary composite material provided by the present application improves the interfacial contact between the ternary positive electrode material and the solid electrolyte, improves the high-voltage resistance performance of the solid electrolyte, and reduces side reactions between the ternary positive electrode and the solid electrolyte and the electrolyte decomposition caused by high voltage. On the other hand, the fast ion conductor property of LixMyFx+3y effectively improves the lithium ion conductivity of the ternary positive electrode material and reduces the residual lithium on the surface of the ternary positive electrode material. The present invention has simple operation, low raw material cost and small equipment investment in the whole preparation process and is suitable for mass production.

The utility model relates to the technical field of aluminum fluoride production, and discloses an aluminum fluoride production device which comprises an aluminum fluoride treatment tank, a connecting tank body is fixedly connected to the top of the aluminum fluoride treatment tank, a crushing tank body is fixedly connected to the top of the connecting tank body, and a raw material crushing mechanism is arranged on the surface of the crushing tank body. An aluminum fluoride preparation mechanism is arranged on the surfaces of the aluminum fluoride treatment tank, the connecting tank body and the crushing tank body, the aluminum fluoride preparation mechanism comprises a mixing treatment assembly and a filtering separation assembly, and after aluminum fluoride is prepared, a discharging valve is started to discharge an aluminum fluoride product in the aluminum fluoride treatment tank out of the aluminum fluoride treatment tank into a separation tank; the aluminum fluoride product is discharged into the separation filter frame to be subjected to solid-liquid separation, the limiting bolt is taken down in the later period, the separation tank can be taken down from the bottom tank, then the separation filter frame can be taken out to recycle the aluminum fluoride product, and solid-liquid separation can be effectively conducted on the aluminum fluoride product through the assembly. Therefore, the finished product quality of the aluminum fluoride product is improved.

The present application relates to a kind of methods for treating fluorine and lithium in acid leaching cathode alkali leaching residue and combined processing alkali leaching waste liquid, belong to aluminum electrolysis waste cathode recovery technical field, the alkali leaching residue of aluminum electrolysis waste cathode is added in AlCl3 solution ultrasonic leaching, and using hydrochloric acid adjusts leaching pH value, after leaching, solid-liquid separation obtains primary carbon powder and first filtrate;First filtrate returns system and is recycled, obtains electrolyte content relatively saturated final leaching solution;Primary carbon powder is washed with deionized water and is treated to obtain high-purity carbon powder;Final leaching solution is mixed with waste cathode alkali waste leaching liquid and is precipitated to obtain lithium-containing cryolite and precipitate liquid, and precipitate liquid can return alkali leaching system and be used for preparing alkali liquor.The present application effectively realizes the recovery of valuable material in alkali leaching residue and alkali leaching waste liquid in aluminum electrolysis waste cathode, simultaneously realizes the harmless treatment of waste cathode, greatly simplifies the recovery process of valuable material in alkali leaching residue and alkali leaching waste liquid of aluminum electrolysis waste cathode.

The invention relates to the technical field of fluorine-containing and silicon-containing solid waste co-processing and resource utilization, and particularly discloses a fluorine-silicon slag gradient high-quality recycling process. According to the process, the fluorine-silicon slag is used as a raw material and is sequentially subjected to the steps of alkali dissolution activation, acidification polymerization, first-stage fluorine removal crystallization, second-stage deep fluorine removal and salt resource recovery, products such as washed white carbon black, magnesium fluoride, cryolite and sodium sulfate are prepared, and meanwhile mother liquor recycling and wastewater reduction are achieved. According to the method, the technological process is short, closed-loop circulation of materials is achieved among the units, the recovery rate of SiO2 in the fluorosilicon slag can reach 95% or above, white carbon black, magnesium fluoride, cryolite and sodium sulfate products meet relevant national or industrial standard requirements respectively, and gradient high-quality recycling and whole-process reduction of the fluorosilicon slag are achieved.

The invention relates to the field of solid-state batteries, in particular to a halide electrolyte, a preparation method thereof and a solid-state battery. The chemical formula of the halide electrolyte is (1-n) Li < 1.4 > Al < 1.4 > Zr < 0.1 > OCl < 4 >. N > LiNbOCl < 4 > (at) x AlF < 3 > (at) y ZnO, nlt; 0 < = x < = 0.3, and 0 < = y < = 0.3. Wherein Li < 1.4 > Al < 1.4 > Zr < 0.1 > OCl < 4 > has good viscoelasticity and plasticity, and can show excellent interface mechanical compatibility under relatively low external pressure; the LiNbOCl4 can be used for improving the ionic conductivity of the electrolyte; alF3 has oxidation-resistant potential and is used for improving the oxidation-resistant potential of the halide electrolyte; znO has excellent air stability and is used for increasing the air stability of the halide electrolyte.

The application provides a lithium manganese iron phosphate positive electrode material and a surface lithiumation compensation process thereof, and belongs to the technical field of new energy batteries. The compensation process comprises the following steps: providing a lithium manganese iron phosphate base material; constructing an interface stabilization layer on the surface of the base material, wherein the interface stabilization layer is a rare earth oxide layer; and constructing a composite functional layer on the interface stabilization layer, wherein the composite functional layer comprises carbon material and composite fluoride, and the composite functional layer simultaneously provides stress buffering and lithium ion conduction functions. The lithium ion battery prepared from the lithium manganese iron phosphate positive electrode material has a significant improvement in cycle life and rate performance, can meet the demand of new energy vehicles and energy storage for high-performance batteries, and has a wide market application prospect.

The application discloses a method for digesting and separating fluorinated aluminum by program, which comprises the following steps: placing a catalyst with metal elements supported on alumina as a carrier into a reaction container of a cluster digestion device, adding hydrochloric acid and / or nitric acid, setting a digestion program, introducing inert gas for pre-pressurization, performing primary digestion, and simultaneously starting a condensation reflux atomizer; after the program is completed, adding hydrofluoric acid, setting a digestion program, and performing secondary digestion; after the digestion is completed, entering a cooling and crystallization program, performing cooling and crystallization, and separating to obtain a sample solution to be detected and a solid; the solid is dried and calcined to obtain fluorinated aluminum crystals, and the liquid is used for detecting the content of metal elements. The method is applied to the digestion treatment of the alumina sample with metal elements supported thereon, has a large sample treatment range, complete digestion, no volatile loss of elements, and can separate AlF3 in an alpha crystal form through the program digestion of the digestion device.

The present application belongs to the technical field of rare earth electrolytic slag resource recycling, and relates to a method for efficiently recycling rare earth and fluorine elements from rare earth molten salt electrolytic slag. The rare earth molten salt electrolytic slag is mixed with a silicon source and calcined to obtain a defluorination calcination slag and a gas phase containing silicon tetrafluoride, the gas phase is introduced into an absorption liquid to react, and fluorosilicic acid dispersion and silicon dioxide are obtained; an acid liquid is added to the solid phase slag to perform leaching reaction, an aluminum source and a sodium source are added to the fluorosilicic acid solution, the pH value is controlled, and cryolite is prepared through precipitation reaction to realize high-value conversion of fluorine. The present application completely converts the insoluble rare earth fluoride into soluble oxide, improves the rare earth leaching rate to more than 98%, recycles and converts the fluorine element which pollutes the environment into high-value cryolite product, realizes the cyclic utilization of silicon dioxide, greatly reduces the raw material cost, has less three-waste emissions, and meets the concept of green production.

This invention belongs to the field of scandium fluoride production technology. It discloses a method for preparing scandium fluoride by gas-solid fluorination of scandium oxide. The method involves placing scandium oxide in a container and then stacking it in a reactor. The temperature is then raised to 100–150°C and held for 1–4 hours. The reactor temperature is then further raised to 200–400°C, and hydrogen fluoride gas is continuously introduced into the reactor and held at the same temperature for 1–4 hours. The tail gas in the reactor is condensed to recover the hydrogen fluoride, and the remaining gas is sent to a spray recovery tower for treatment. The reactor temperature is then raised to 600–800°C and held for 8–24 hours. The reactor and gas are then stopped, and the gas inside the reactor is vented into the spray recovery tower. Finally, argon gas is introduced into the reactor to exhaust the exhaust gas, and the reactor is cooled to room temperature to obtain the scandium fluoride product. This method is simple and easy to operate, and can produce scandium fluoride with high purity and low moisture content, which is beneficial for its application in high-end manufacturing fields such as precision instruments, satellite structures, and optical platforms.

The solid electrolyte contains Na, M [alpha], M [beta], and F, where M [alpha] is at least one element that is a trivalent cation, and M [beta] is at least one element that is a tetravalent or higher cation. As a result, it is possible to provide a solid electrolyte having high ion conductivity. Preferably, M [beta] is an element having a tetravalent cation, the solid electrolyte contains a component represented by the compositional formula Na3-xM [alpha] 1-xM [beta] xF6, and 0 < x < 1 is satisfied.

The present application relates to a kind of aluminium electrolysis solid waste processing method, comprising the following steps: providing aluminium electrolysis solid waste powder;Wherein, the aluminium electrolysis solid waste powder includes overhaul slag and waste slag, the overhaul slag includes one or several of waste refractory material and waste cathode, the waste slag includes one or two of waste carbon residue and waste electrolyte, and the mass ratio of overhaul slag and waste slag is 6-8:1-4;The aluminium electrolysis solid waste powder is mixed with water at 1:3-5 solid-liquid mass ratio, after reaction at 80-95 DEG C, solid-liquid separation, obtains leaching residue and leaching solution;After acid leaching to the leaching residue, solid-liquid separation, obtains acid leaching residue and lithium-rich acid leaching solution.The processing method of the present application can simultaneously realize to aluminium electrolysis waste refractory material, waste slag and other various aluminium electrolysis solid waste.The processing method of the present application can realize the full quantization recovery of carbon, lithium, cryolite and other substances in aluminium electrolysis solid waste, and the economic benefit is good.

The invention relates to the technical field of dangerous solid waste treatment and resource utilization, in particular to an aluminum electrolysis overhaul slag fluoride enhanced leaching and resource recycling method. Comprising the following steps: adding pretreated overhaul slag into a complexing reaction solution of boric acid containing a dispersing agent and gluconate, and pulping; sealing the system, heating, and implementing pulse type micro-negative pressure degassing operation in which vacuumizing and normal pressure recovery are alternated during constant-temperature leaching; after the reaction is finished, carrying out thermal-state solid-liquid separation and tailing washing, and merging to obtain clear filtrate; crystal seeds are added into the filtrate, an aluminum source solution is dropwise added, the pH value is increased, solid-liquid separation is performed after constant-temperature curing, and synthetic cryolite is obtained; and supplementing the pH buffer agent to the clear liquid and then circularly returning to the liquid preparation process. According to the method, fluorine and aluminum are cooperatively extracted under the weak acid condition, generation of silicic acid gel is inhibited, equipment corrosion is reduced, mass transfer in pores is enhanced in combination with micro-negative pressure operation, and low-energy-consumption recovery of fluoride salt and closed-loop circulation of a working solution are achieved through pH regulation and control.

To provide a double fluoride composite capable of producing a dense molded article without using an auxiliary agent.SOLUTION: The complex fluoride composite has a core-shell structure of a core of a crystalline component or an amorphous component of a complex fluoride containing fluorine, an alkali metal element and a second metal element different from the alkali metal element, and a shell of an amorphous component or a crystalline component of a complex fluoride covering a part of the core, wherein the second metal element is at least one metal element selected from the group consisting of an alkaline earth metal element, aluminum, gallium, indium, zinc and yttrium.SELECTED DRAWING: Figure 1

The present disclosure relates to sorbents for selective metal extraction from solutions, and more specifically, to highly hydrated lithium-incorporated aluminum-hydroxide (HHA) configured for lithium extraction. 2 The present disclosure relates to compositions comprising 2 The H-LIAH compositions of the present disclosure are distinguished from conventional LIAH compositions at least in part by their crystallization-hydrate to lithium molar ratio, which is readily detectable by analytical characterization. 2 The LIAH compositions of the present disclosure can be readily: (i) prepared by the manufacturing methods described herein; (ii) incorporated into an apparatus for recovering lithium from saltwater described herein; and / or (iii) deployed in a method for recovering lithium from saltwater described herein. 2 The -LIAH composition was developed after discovering a surprising pH effect that induces the unexpected formation of a gel-like material during manufacturing. The gel-like material is a H that has unconventional properties as described herein. 2 -Can be tailored to the LIAH composition.

Disclosed is a method for efficiently removing fluorine from a spent lithium battery. The method comprises: mixing aluminum and a sodium hydroxide solution for reaction to obtain a sodium metaaluminate solution; introducing sulfuric acid into the sodium metaaluminate solution, and stirring to react at a certain temperature to obtain a fluorine removal agent; adding a sodium fluoroaluminate seed crystal and the fluorine removal agent into an impurity-removed battery powder leaching solution, introducing a sodium carbonate solution at the same time, performing reaction at a certain temperature, controlling the pH value of a reaction endpoint, and performing solid-liquid separation after the reaction is finished to obtain a fluorine-removed liquid and filter residues; and adding the sodium hydroxide solution into the filter residues for reaction, and performing solid-liquid separation to obtain a filtrate containing fluorine and aluminum, and insoluble residues. According to the present invention, fluorine removal is induced by adding the sodium fluoroaluminate seed crystal; and during fluorine removal, the seed crystal sodium fluoroaluminate is firstly added into the battery leaching solution, and by means of induction of the seed crystal, combination of fluorine and aluminum in the solution can be accelerated to generate sodium hexafluoroaluminate, the reaction time is shortened, the fluorine removal efficiency is improved, and fluorine in the solution can be removed to be lower than 20 mg / L, thereby achieving the purpose of deep fluorine removal.

The invention relates to a method for extracting lithium from waste electrolyte and preparing cryolite in a linkage manner, and belongs to the technical field of resource recovery and inorganic material preparation. According to the method, through the steps of pretreatment, selective leaching, impurity removal and purification, lithium salt preparation, fluorine and aluminum synergistic reaction and the like, efficient recovery of lithium resources in the waste electrolyte is achieved, meanwhile, high-purity cryolite is prepared in a linkage mode, and the problems that in the traditional waste electrolyte treatment process, the resource utilization rate is low, secondary pollution is serious, and the added value of products is low are solved. The method is short in process route, low in energy consumption and good in environmental protection property, achieves the purposes of treating waste with waste and recycling resources, and has remarkable economic and environmental benefits.