2346results about "Lithium carbonates/bicarbonates" patented technology

The invention relates to a waste lithium iron phosphate battery recycling method, in particular to a graded recycling method for lithium, iron, phosphorus and graphite in a waste lithium iron phosphate battery, and belongs to the technical field of lithium ion batteries and resource recycling of the lithium ion batteries. According to the method, the mode that oxidizing roasting and selective leaching are combined is adopted, the leaching rate and selectivity of lithium are effectively improved, the leaching rate of the lithium element is close to 100% under the optimized condition, and limit recovery of the lithium element is achieved; meanwhile, aiming at the problem that iron and phosphorus in the leaching residues are difficult to utilize, a wet ball milling and secondary acid leaching method is combined, phosphorus and iron elements are separated from negative electrode graphite firstly, and graded recovery of iron, phosphorus and graphite is achieved. According to the method, the high recovery rate of lithium is realized, and meanwhile, high-added-value products such as ferric oxide and sodium phosphate are prepared by efficiently recovering ferric phosphate.

The invention discloses a method for recycling lithium in a lithium battery, and belongs to the field of lithium battery recycling. The method comprises the following steps: decomposing the lithium battery, and performing pyrolysis treatment at 200-500 DEG C to obtain a slag material; the slag charge is placed in a composite leaching agent, the pH is adjusted to 1.5-2.5, lithium in the slag charge is leached out, and a leaching solution is obtained; the composite leaching agent comprises oxalic acid, an amino acid ligand, persulfate and fluorine ions; adjusting the pH value of the leaching solution to 5.5-6.2, adding an extracting agent into the leaching solution, extracting lithium ions in the leaching solution, and separating to obtain a lithium-rich organic phase and lithium-containing waste liquid; the extraction agent comprises crown ether and organophosphate; and the lithium-rich organic phase is subjected to back extraction, so that lithium ions are released from the organic phase, a lithium-rich back extraction solution is obtained, a carbonate solution is added into the lithium-rich back extraction solution, and lithium carbonate precipitates are obtained. According to the method for recycling the lithium in the lithium battery, selective leaching of the lithium can be achieved, and the comprehensive yield of the lithium in the lithium battery is increased.

The invention discloses a waste battery lithium iron phosphate positive electrode black powder recovery method which comprises the following steps: S1, activating and roasting positive electrode black powder to obtain pretreated black powder, and mixing and ball-milling the pretreated black powder, an oxidizing agent and an activating solvent to obtain pre-oxidized black powder; s3, the pre-oxidized black powder and an inorganic solvent are mixed for a leaching reaction, and mother liquor A and iron phosphate slag are obtained; s4, adding a pH regulator into the mother liquor A to remove impurities so as to obtain mother liquor B; s5, mixing and purifying the iron phosphate slag and phosphoric acid to obtain crude iron phosphate, washing the crude iron phosphate with water, and adding a complexing agent for further purification to obtain high-purity iron phosphate; and S6, concentrating the mother liquor B to obtain concentrated mother liquor C, and introducing carbon dioxide into the concentrated mother liquor C to precipitate lithium to obtain the battery-grade lithium carbonate. According to the process, iron, lithium, phosphorus and other elements in the positive electrode black powder are efficiently separated and recycled, low-acid or acid-free green leaching of lithium is achieved, the lithium leaching rate is larger than or equal to 98.0%, and the purity of obtained iron phosphate is larger than or equal to 99.3%; the purity of lithium carbonate is greater than or equal to 99.0%.

The invention relates to a comprehensive recovery method of lithium iron phosphate black powder, and belongs to the technical field of lithium iron phosphate battery recovery. The technical problem to be solved by the invention is to provide the lithium iron phosphate black powder comprehensive recovery method. The method comprises the following steps: mixing lithium iron phosphate black powder with acid, and adding an oxidizing agent for reaction to obtain iron phosphorus slag; the iron phosphorus slag is subjected to acid pickling and then acid leaching to obtain secondary acid leaching liquid; and dropwise adding the secondary acid leaching solution into bottom water to generate a precipitate, and adjusting the molar ratio of phosphorus to iron or the molar ratio of phosphorus to (iron and manganese) to obtain battery-grade iron phosphate or ferromanganese phosphate. According to the method, alkali is not adopted as a precipitator, iron powder is not introduced, iron phosphate or the ferromanganese phosphate precursor is obtained through a normal-pressure one-step method, the problems that mixing is not uniform when the ferromanganese phosphate precursor is prepared through a solid-phase method, and alkali is needed as the precipitator or organic matter is introduced in a liquid-phase method are solved, use of alkaline chemical reagents and generation treatment of by-products are reduced, and the method is suitable for industrial production. The method has the advantages of simple process, low equipment use requirements, battery grade and high purity of the prepared product, improves the utilization rate of the phosphorus source, and has high yield.

A method for recycling waste lithium iron phosphate, belonging to the technical field of material recycling. The method specifically separately reprocesses the precipitate and leachate obtained by separating and leaching waste lithium iron phosphate powder, using membrane concentration to highly enrich the lithium ions in the leachate and fully utilizing the filtrate generated during the treatment process, and ultimately can simultaneously and efficiently recover and obtain lithium salt and iron phosphate products. The entire method can achieve a lithium recovery rate of 95% or greater for waste lithium iron phosphate, the maximum concentration of impurity elements in the obtained iron phosphate not exceeding 5 ppm, and the quality of the iron phosphate product being relatively high.

The present disclosure relates to the field of sodium-ion battery technology, and specifically, to a method for preparing carbon-coated sodium iron fluorophosphate from waste lithium iron phosphate and the application thereof. The method for preparing carbon-coated sodium iron fluorophosphate from waste lithium iron phosphate includes: mixing a waste lithium iron phosphate material with an alkaline solution for reaction, followed by solid-liquid separation, to obtain an aluminum-containing filtrate and a lithium iron phosphate filter residue; mixing the lithium iron phosphate filter residue, aluminum chloride and sodium chloride uniformly, followed by vacuum calcination, to obtain a calcination material; and mixing the calcination material with at least one of a sodium source, an iron source and a phosphorus source uniformly to obtain a mixture to which a fluorine source, a carbon source and a solvent are added for uniformly mixing, followed by drying and calcination sequentially to obtain the carbon-coated sodium iron fluorophosphate. The method has the advantages of low costs, a high added value, a short process, and a high recovery rate, and the carbon-coated sodium iron fluorophosphate obtained from the method has excellent electrochemical performance.

The invention discloses a method for preparing battery-grade iron phosphate and lithium carbonate from a waste lithium iron phosphate battery, and belongs to the technical field of lithium batteries, the method comprises the following steps: slurrying a waste lithium iron phosphate positive electrode material, adding concentrated sulfuric acid for leaching, adding sodium sulfite, controlling reaction potential, and carrying out filter pressing after reaction to obtain a leachate; iron is added into the leachate to remove copper, and copper-removed liquid and copper slag are obtained after filter pressing; adding sodium dihydrogen phosphate into the copper-removed liquid to remove aluminum, and carrying out filter pressing to obtain aluminum slag and impurity-removed liquid; adjusting the pH value of the impurity-removed solution, adding hydrogen peroxide, reacting to obtain an iron phosphate dehydrate precipitate and an iron phosphate mother solution, and treating the iron phosphate dehydrate to obtain battery-grade anhydrous iron phosphate; adjusting the pH value of the iron phosphate mother liquor, carrying out filter pressing to obtain impurity-removed slag and a lithium sulfate solution, adding sodium carbonate into the lithium sulfate solution, carrying out heating reaction, filtering slurry to obtain a lithium carbonate wet material, and treating to obtain battery-grade lithium carbonate. According to the method, the problem of recycling the waste lithium iron phosphate battery material iron phosphate is solved, and comprehensive recycling of the iron phosphate and the lithium material is realized.

The invention discloses a method for preparing a manganese iron phosphate precursor by recycling waste lithium manganese iron phosphate, and belongs to the technical field of lithium ion batteries. The invention provides a method for preparing a manganese iron phosphate precursor by recycling waste lithium manganese iron phosphate, which comprises the following steps: by taking waste lithium manganese iron phosphate battery powder as a raw material, carrying out acid dissolution and filtration to remove graphite and part of impurities; adjusting the pH value of the filtrate to obtain a lithium-ion-rich solution and a ferromanganese precipitate, and adding sodium carbonate into the lithium-ion-rich solution for concentration and crystallization to obtain battery-grade lithium carbonate; carrying out acid dissolution on the ferromanganese precipitate, removing copper and aluminum impurities in the solution, adjusting the ratio of ferromanganese to phosphorus, and mixing with liquid caustic soda in a nitrogen atmosphere to obtain a ferromanganese phosphate precursor; according to the method, the problems of incomplete recovery and insufficient impurity removal of the manganese iron phosphate lithium battery are solved, the battery-grade lithium carbonate and the manganese iron phosphate precursor are prepared during recovery, the value of the recovered product is improved, and the production requirement of the lithium ion battery is met.

A process and apparatus for lithium ion extraction. The process includes passing a lithium-containing brine through a lithium-adsorbent, then passing a desorption media through the lithium-adsorbent at a temperature above 40℃ to produce a lithium-enriched eluent. The lithium concentration of the eluent is further increased by passing it through a nanofiltration membrane and a reverse osmosis membrane. Preferably, the eluent is passed through these membranes more than once at a temperature above 40℃. The process is energy-efficient, because it is conducted entirely at temperatures above 40℃. Accordingly, there is no need to decrease the temperature of the lithium-enriched eluent before passing it through the nanofiltration membrane and the reverse osmosis membrane. Moreover, there is no need to increase the temperature of the nanofiltration reverse osmosis permeate before passing it through the lithium-adsorbent as a desorption media, nor is there a need to increase the temperature of the enriched lithium stream before lithium precipitation.

Disclosed is a method for short-range recovery of a valuable metal from a waste ternary lithium battery. By means of the steps of nickel and cobalt precipitation by a two-stage chemical precipitation method and trisodium phosphate-based lithium precipitation, the problem in the prior art of high content of impurities in lithium carbonate is solved and high-quality lithium carbonate is obtained; in addition, the whole process is carried out in a normal pressure environment. Compared with the complex process of recovering nickel, cobalt, and manganese metals by an extraction + MVR evaporative crystallization method and recovering a lithium metal after MVR concentration, the demand of a waste ternary lithium battery recovery process for energy consumption and the pollution of the waste ternary lithium battery recovery process to the environment are greatly reduced, and industrial production is facilitated.

The invention provides equipment and a process for extracting lithium from lepidolite frame residues and synthesizing urea gypsum, and relates to the technical field of solid waste resource recycling, the equipment comprises a reaction tank, a sealing plate, a reciprocating motion mechanism and a multi-point detection mechanism; the reciprocating motion mechanism comprises a bidirectional threaded lead screw and a threaded block, the bidirectional threaded lead screw is transversely and rotatably connected to the inner wall of the reaction tank, the threaded block is in threaded connection with the bidirectional threaded lead screw, and the bottom of the threaded block is slidably connected with a guide seat. According to the scheme, when the top of a rotating wheel is in contact with a concave position of a convex plate, a rotating seat can drive a sliding rod and a PH detector to move upwards under the action of a spring, so that the bottom end of the PH detector is separated from filtrate, and a plurality of convex parts are arranged on the convex plate, so that the filtrate is subjected to multi-point real-time detection; lithium ion loss caused by co-precipitation of lithium, iron and aluminum due to over-high local pH value of the filtrate is avoided, and the concentration of the lithium solution is effectively improved.

The invention relates to the technical field of membrane separation and resource recovery, and discloses a bipolar membrane electrodialysis device for synchronously capturing carbon dioxide, extracting lithium and producing lithium carbonate. The device utilizes a selective bipolar membrane electrodialysis system to extract lithium ions from liquid resources such as spodumene leachate, brine, oil and gas field wastewater, seawater and the like, and converts the lithium ions into lithium hydroxide. And meanwhile, introducing flue gas containing carbon dioxide into the generated lithium hydroxide solution by using a gas disperser to generate lithium carbonate. Therefore, mineralization capture of carbon dioxide in the flue gas, extraction of lithium ions in liquid resources such as spodumene leachate, brine, oil and gas field wastewater and seawater and production of lithium carbonate are synchronously realized, waste is treated by waste, and the method has the advantages of simple process, high lithium ion yield, short period, environmental friendliness, no pollution, continuous production and the like, and is suitable for industrial production. The method has important significance on carbon dioxide capture, lithium resource recovery and development of the new energy industry.

The invention provides a lithium precipitation mother liquor lithium recovery method based on countercurrent centrifugal extraction. The method comprises the following steps: S1, pretreating a lithium precipitation mother liquor to obtain a lithium-containing pre-extraction solution; s2, conveying the lithium-containing pre-extraction liquid to a centrifugal extraction system, fully mixing the lithium-containing pre-extraction liquid with an organic phase, and sequentially carrying out multi-stage countercurrent centrifugal extraction; performing phase splitting to obtain raffinate and a lithium-loaded organic phase; s3, the lithium-loaded organic phase enters a washing section to be subjected to multi-stage countercurrent centrifugal washing; s4, performing multi-stage countercurrent centrifugal reverse extraction on the washed lithium-loaded organic phase to obtain a lithium-rich solution; and S5, synthesizing the lithium-rich solution and a sodium carbonate solution to obtain the battery-grade lithium carbonate. The lithium recovery method has the characteristics of rapidness, high efficiency, low equipment investment, small occupied area, less extraction agent consumption and short process flow.

The present disclosure relates to the extraction of lithium from underground reservoirs of naturally occurring brines. Described herein are systems and methods to extract lithium entrapped within reservoirs that were previously inaccessible.

The invention provides a method for recycling lithium iron phosphate, which comprises the following steps: S1, obtaining lithium iron phosphate black powder, and washing the lithium iron phosphate black powder by using alkali liquor to obtain aluminum-removed black powder and aluminum-containing lithium filtrate; s2, the aluminum-removed black powder is subjected to acid leaching treatment with acid liquor, and acid leaching liquor is obtained; s3, carrying out reduction precipitation treatment on the acid leaching solution by using a composite reducing agent to obtain a copper-removed leaching solution and solid-phase copper-containing slag; s4, adding a phosphorus source and an oxidizing agent into the copper-removed leaching solution, adding alkali to adjust the pH value, and carrying out oxidation precipitation treatment to obtain iron phosphate precipitate and a first lithium-containing solution; and S5, adjusting the pH value of the aluminum-lithium-containing filtrate in the step S1 by using an acid solution to obtain aluminum filter residues and a second lithium-containing solution. According to the method, iron phosphate with relatively high purity can be obtained; meanwhile, the obtained first lithium-containing solution and the second lithium-containing solution are relatively low in impurity ion content and can be used for obtaining a lithium salt product with relatively high purity.

The invention provides a method for recovering a lithium iron phosphate material from a waste battery, and relates to the technical field of battery material recovery. The method comprises the following steps: pre-treating the waste battery; treating a positive plate; and material recovery. Wherein the positive plate treatment specifically comprises the step of soaking the positive plate by adopting a first soaking agent. And crushing the positive plate soaked in the first soaking agent. Soaking the crushed positive plate in a second soaking agent, and filtering to obtain a first filter residue taking the positive active material as a main component; and drying, grinding and screening the first filter residue to remove impurities so as to obtain the lithium iron phosphate impurity-removed material. According to the method for recovering the lithium iron phosphate material from the waste battery, provided by the invention, impurities in the recovered lithium iron phosphate material can be reduced, and the purity of the recovered lithium iron phosphate material is increased; the performance of the lithium iron phosphate material synthesized again after the lithium iron phosphate in the waste battery is recycled can meet the brand-new battery-grade raw material requirement.

A method including pretreating ground lithium-containing ceramics to form alkali coated ceramics, leaching the alkali coated ceramics to form a leachate comprising a filtrate and a solid residue, preferentially extracting lithium from the filtrate to form a lithium rich solution and a raffinate, precipitating a crude lithium carbonate from the lithium rich solution and purifying the crude lithium carbonate to produce a battery grade lithium carbonate. A method including leaching a slurry comprising lithium-containing ceramics, water, a strong base, and an alkaline earth metal oxide / hydroxide at a pressure ranging from 0 to 1450 psi and at a temperature ranging from 100 to 500°C to form a leached slurry comprising a liquid filtrate and a solid residue, processing the liquid filtrate to recover a lithium-rich organic solution, and processing the lithium-rich organic solution to produce a battery-grade lithium compound and sodium sulfate.

The invention relates to the technical field of aluminum electrolyte recovery, in particular to a waste aluminum electrolyte resource utilization method. The waste aluminum electrolyte resource utilization method comprises the following steps that waste aluminum electrolyte and a reactant are subjected to a reaction in a closed container, a product obtained after the reaction is completed is washed in water, then first solid-liquid separation is carried out to obtain a solid, aluminum fluoride is obtained after drying, and aluminum fluoride is obtained after second solid-liquid separation is carried out. The reactant is selected from one or two of anhydrous aluminum chloride and polyaluminum chloride, and the reaction temperature is not lower than 200 DEG C. By utilizing the physical characteristic that the melting point of the reactant is higher than the boiling point, the reactant forms a solid phase-liquid phase-gas phase three-phase coexistence system in a closed space at the temperature higher than the melting point and the boiling point, so that the reactant can more efficiently perform molecular collision and mutual diffusion at an interface, thereby accelerating the reaction rate and improving the conversion rate.

The invention discloses an adsorbent / catalyst based on waste lithium battery recovery and a preparation method and application thereof, and the preparation method comprises the following steps: discharging and disassembling a waste lithium battery, mixing and ball-milling the obtained positive electrode material, metal scrap, PVC and negative electrode graphite material, adding water in the ball-milling process, and carrying out mechanochemical reaction; and after the ball milling is finished, carrying out water leaching treatment on a ball milling product, drying filter residues after the water leaching treatment, and calcining in an inert atmosphere at the calcining temperature of 350-900 DEG C for 0.5-4 hours to obtain the pollutant removal adsorbent / catalyst. The process flow is completed at normal temperature and normal pressure by adopting a mechanochemical method, high-temperature operation is not needed, and the problem of high energy consumption of pyrometallurgy is avoided. Meanwhile, strong acid or strong alkali is not used, no waste liquid or toxic gas is discharged, and compared with a traditional wet metallurgy / wet modified adsorbent / catalyst process, a resource recovery and material preparation technology which is more environmentally friendly and conforms to the green and low-carbon concept is achieved.

The invention discloses a method for preparing lithium carbonate from positive electrode material waste liquid, and relates to the technical field of lithium carbonate preparation. Comprising the following steps: adding hydrogen peroxide and sulfuric acid into the positive electrode material waste liquid, and carrying out solid-liquid separation to obtain an iron phosphate / carbon black solid mixture and a lithium-containing solution; adding a flocculating agent into the lithium-containing solution to perform primary impurity removal, filtering, performing secondary impurity removal through electric descaling, and performing suction filtration to obtain a lithium-containing purified solution; heating and concentrating the lithium-containing purified solution to obtain a concentrated solution; a sodium carbonate solution is added into the concentrated solution for a lithium precipitation reaction, and crude lithium carbonate and lithium precipitation mother liquor are obtained; uniformly mixing the crude lithium carbonate with water to obtain slurry, introducing CO2, carrying out hydrogenation reaction under a supergravity condition, and filtering after the reaction is finished to obtain a lithium bicarbonate solution; and carrying out thermal decomposition reaction on the lithium bicarbonate solution under a supergravity condition, adding a nucleating agent at the same time, and after crystals are separated out, carrying out suction filtration to obtain a lithium carbonate product and crystallization mother liquor. According to the method, lithium carbonate is prepared under the supergravity condition, coating and inclusion of foreign ions in the nucleation growth process can be avoided to a great extent, and a lithium carbonate product with relatively high purity is prepared.

The invention provides a method for preparing battery-grade lithium carbonate by using waste lithium iron phosphate batteries. The method comprises the following steps: step 1, discharging, disassembling and crushing the waste lithium iron phosphate batteries to obtain lithium iron phosphate battery powder; 2, adding a sulfuric acid solution and hydrogen peroxide into the lithium iron phosphate battery powder, and filtering after reaction to obtain a lithium-containing solution and ferrophosphorus slag; 3, calcium hydroxide and sodium hydroxide are sequentially added into the lithium-containing solution to remove impurities, then sodium carbonate is added, and a purified lithium solution is obtained through filtering; 4, adding an organic solvent into the purified lithium solution, fully stirring, and filtering to obtain a sodium sulfate crystal substance and an organic mixed solution; and 5, adding sodium carbonate into the organic mixed solution, fully reacting, filtering, and washing to obtain the battery-grade lithium carbonate.

Provided are methods of extracting lithium from a lithium containing solution, as well as the resulting compositions. The method includes supplying a lithium containing solution to a lithium capture step, the lithium capture step being operable to capture lithium from the lithium salt containing solution. The method further includes recovering lithium from the lithium capture step to produce a lithium rich stream. In especially preferred methods, the lithium capture step is performed to increase the lithium to sodium ratio above at least 1:1. Optionally, the lithium rich stream can be purified to remove divalent ions and borate ions. The lithium rich stream is then concentrated by supplying the lithium rich stream to a reverse osmosis step to produce a concentrated lithium rich stream.

The invention belongs to the field of electrochemistry, and particularly relates to a method for electrochemical lithium extraction of a decommissioned lithium battery assisted by a pseudocapacitor cathode, which comprises the following steps: a) providing an anode electrode and a cathode electrode; the anode electrode is an anode electrode made of a recycled retired lithium battery anode material or an retired lithium battery anode plate; the cathode electrode contains a Prussian blue analogue, the Prussian blue analogue is prepared by mixing citrate, transition metal salt and cyanide in water for reaction, and the transition metal salt is one or more of cobalt salt, ferric salt, copper salt and nickel salt; and b) immersing the anode electrode and the cathode electrode into the electrolyte, and electrifying to carry out electrochemical lithium extraction. According to the method, a pseudocapacitance material with a lithium discharging characteristic is adopted as a cathode to replace a common metal pole plate or a carbon material, a pseudocapacitance reaction with a corrected electrode potential is adopted to replace a hydrogen evolution reaction on the cathode of an existing system, and finally, low-energy-consumption and high-selectivity recovery of lithium is realized.

The invention relates to the technical field of extraction and utilization of electrolytic aluminum lithium-containing waste, in particular to a method for selectively extracting lithium from electrolytic aluminum waste. The method comprises the following steps: (1) coarsely crushing the electrolytic aluminum waste; (2) calcining or combusting the electrolytic aluminum waste to remove carbon; (3) carrying out two-stage lithium leaching on the carbon-removed filter residues by controlling leaching conditions; (4) performing two-stage impurity removal on the lithium leachate; and (5) concentrating and denitrifying the impurity-removed liquid, precipitating lithium, carbonizing and crystallizing to prepare the battery-grade lithium carbonate. According to the method, after carbon in the electrolytic aluminum waste is removed through a calcination or combustion method, lithium in the waste aluminum slag is dissolved out into the leaching solution by controlling the leaching conditions, and aluminum, iron, sodium and most fluorine in the waste aluminum slag are not dissolved out and are left in the leaching slag. And performing simple impurity removal, concentration and denitration on the leachate to prepare the battery-grade lithium carbonate. The method is simple in process, low in reagent consumption and high in lithium extraction rate.

The invention provides a method and equipment for producing Li2CO3 based on coordinated roasting of lepidolite and spodumene. The method for producing Li2CO3 based on coordinated roasting of lepidolite and spodumene comprises the steps that S1, ore pretreatment is conducted, specifically, lepidolite and spodumene with the particle size smaller than 5 mm are evenly mixed according to the mass ratio of 1: (1-3), and the mixed ore is finely ground till the particle size is smaller than 75 microns; s2, additive mixing, wherein a composite additive is added into the mixed ore obtained after fine grinding and evenly mixed with the ore, and the composite additive is composed of fluoride, sulfate and a fluxing agent; and S3, coordinated roasting, wherein the mixed materials are fed into a rotary kiln to be roasted. According to the method for producing Li2CO3 based on coordinated roasting of the lepidolite and the spodumene, the lepidolite and the spodumene are roasted in a coordinated mode, the structural and chemical property differences of the lepidolite and the spodumene are utilized, advantage complementation is achieved, the overall extraction rate of lithium is increased, compared with a single lithium extraction technology, the lithium recovery rate can be increased by 10%-20%, and the waste residue generation amount is reduced.

The invention discloses a method for recycling a waste lithium battery positive electrode material, and relates to the technical field of lithium battery positive electrode materials. When the lithium battery positive electrode material is prepared, the waste lithium iron phosphate battery is discharged and then disassembled, a current collector is separated through cyclic soaking in cold and hot water, lithium ions are selectively leached through sulfuric acid-hydrogen peroxide after calcination, and the recycled lithium carbonate is obtained through recycling; preparing a carbonic acid ternary precursor by using a coprecipitation method; mixing the carbonic acid ternary precursor, recycled lithium carbonate, silicon monoxide, lithium fluoride and neodymium oxide, and performing secondary calcination to obtain a doped modified ternary positive electrode material; compounding and coating lanthanum, aluminum and zinc on the surface of the doped modified ternary positive electrode material by using a potassium-sodium alloy reduction method to prepare a coated modified ternary positive electrode material; and mixing the coated modified ternary positive electrode material with a conductive agent and a binder, and coating a carbon-coated aluminum foil with the mixture to prepare the lithium battery positive electrode material. The lithium battery positive electrode material prepared by the invention has high charge-discharge specific capacity, long cycle life and good rate capability.

The invention discloses a method for directly extracting lithium from lithium-containing brine by adopting an adsorption process, which comprises the following steps of: feeding pretreated brine into a continuous countercurrent adsorption system comprising an N-stage continuous overflow adsorption stirring tank, and extracting lithium from the lithium-containing brine through N-stage continuous countercurrent adsorption, then the washed loaded adsorbent is fed into a continuous countercurrent desorption system containing M-stage continuous overflow desorption stirring tanks, and desorption of lithium is achieved through M-stage continuous countercurrent desorption; the lithium-rich liquid obtained through desorption is pretreated and then subjected to reverse osmosis, nanofiltration and further concentration, and finally the obtained concentrated liquid is prepared into the required lithium product. Compared with the traditional lithium extraction process, the method provided by the invention has the advantages of low equipment requirement, low investment, high adsorption and desorption rate, high adsorbent utilization rate and controllable desorption process, and can flexibly adapt to the change of lithium concentration and capacity of the brine.

The invention relates to recycling treatment of waste lithium iron phosphate batteries, and provides a method for recycling metals in waste lithium iron phosphate batteries based on advanced oxidation and application. The type of the waste lithium battery is a soft package type lithium iron phosphate battery, a positive electrode material in the waste lithium iron phosphate battery is obtained through simple discharge and disassembly of an instrument, after grinding, positive electrode material powder and an oxidizing agent are mixed and reacted with water in a reactor according to a certain proportion, lithium ions are released into an aqueous solution, and the lithium ion battery is obtained. Sodium carbonate is added for evaporation and filtration, and lithium is recycled in the form of lithium carbonate. The invention provides a new scheme for selectively recovering lithium in the waste lithium iron phosphate battery, and the scheme has the characteristics of simple recovery process and high efficiency.

The invention discloses a method for extracting lithium from gas field produced water with a high sodium-lithium ratio, and belongs to the technical field of chemical engineering. The mass ratio of sodium to lithium in the gas field produced water is (100-1000): 1, and the method comprises the following steps: S1, nanofiltration: carrying out nanofiltration on the gas field produced water, and intercepting divalent ions to obtain nanofiltration produced water and nanofiltration concentrated water; s2, adsorbing and extracting lithium, namely adjusting the pH value of the sodium-filtered produced water, treating the sodium-filtered produced water through a lithium-sodium adsorption and separation device filled with an adsorbent to realize sodium-lithium separation, and collecting the adsorbed lithium-extracted produced water; s3, desorption of lithium ions: eluting the adsorbent with an acid solution to desorb the lithium ions from the adsorbent, and collecting an eluent; s4, concentration: carrying out reverse osmosis treatment on the eluent, and treating the reverse osmosis concentrated solution through an electrodialysis device to obtain a concentrated lithium-containing concentrated solution; and S5, lithium precipitation: adjusting the pH value of the lithium-containing concentrated solution, adding a lithium precipitation agent, and crystallizing and precipitating lithium to obtain industrial-grade lithium carbonate. The process is simple, the lithium recovery rate during lithium precipitation can be effectively increased, and full-automatic continuous operation can be achieved.

The present invention relates to the extraction of lithium from liquid resources such as natural and synthetic brines, leachate solutions from clays and minerals, and recycled products.