1416results about "Lithium carbonates/bicarbonates" patented technology

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.

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 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 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 present invention provides a system and method for extracting lithium from salt lake brine and preparing battery-grade lithium carbonate. The system includes a coagulation and precipitation system, a filtration system, an adsorption and desorption system, a calcium and magnesium removal system, a boron removal system, a concentration system, an evaporation system, and a lithium precipitation system connected in sequence. The calcium and magnesium removal system includes a first-stage reverse osmosis concentration unit, a first-stage nanofiltration calcium and magnesium removal unit, a second-stage reverse osmosis concentration unit, a multi-stage nanofiltration calcium and magnesium removal unit, and a calcium and magnesium ion exchange unit connected in sequence. The boron removal system includes a first-stage nanofiltration boron removal unit, a multi-stage nanofiltration boron removal unit, and a boron ion exchange unit connected in sequence. After the lithium precipitation system, there are also a precision filtration system and a water washing and drying system connected in sequence. By adopting the process of the present invention, the lithium recovery rate is improved, and the product is battery-grade lithium carbonate, greatly improving the resource utilization and recovery rate of the lithium extraction system, reducing the amount of externally added water and the consumption of sodium carbonate in the process of the lithium precipitation system.

To provide an extractant for selectively extracting lithium salt, a method for recovering lithium salt, and a method for producing lithium salt.SOLUTION: A lithium salt extractant comprises at least one selected from a group consisting of a compound represented by a general formula (1) and a compound represented by the general formula (2) (where X1, X2, X3 and X4 independently represent an oxygen atom, a sulfur atom, a sulfinyl group, a sulfonyl group, a carbonyl group, or an imino group).SELECTED DRAWING: None

The invention provides a method for recovering all elements of a waste lithium iron phosphate battery positive electrode material. The method comprises the following steps: crushing the waste lithium iron phosphate positive electrode material, and performing nitrogen airflow crushing; adding hydrogen peroxide into the crushed material, performing ultrasonic treatment for multiple times, and performing microwave radiation treatment while performing ultrasonic treatment to obtain a mixture; diluted hydrochloric acid is added into the mixture, ultrasonic treatment is carried out multiple times while stirring is carried out, microwave radiation treatment and filtering are carried out while ultrasonic treatment is carried out, the pH value is adjusted to 3.5-4, then stirring and standing are carried out, a leaching material is obtained, filtering is carried out, and leaching residues and a leaching solution are obtained; the leaching residues are dried and roasted, and iron phosphate is obtained; concentrating the leachate, adjusting the pH value to 9.5-10, standing, filtering, and dropwise adding a sodium carbonate aqueous solution for reaction; and filtering and drying to obtain lithium carbonate. According to the recycling method, resource recycling of all elements can be achieved, the overall recycling rate of iron and lithium is high, and the purity of obtained lithium carbonate and iron phosphate is high.

The invention discloses a method for separating iron and lithium in a lithium iron phosphate iron salt leaching solution and recycling iron phosphate, and belongs to the technical field of waste lithium battery recycling. The method comprises the following steps: constructing a bis (2-ethylhexyl) phosphate and trioctyl decyl tertiary amine mixed extraction system for selective extraction of Fe < 3 + >, adopting phosphoric acid for reverse extraction, recycling phosphoric acid reverse extraction liquid, preparing iron phosphate and the like. According to the method, efficient enrichment of Fe < 3 + > and efficient elution of Fe < 3 + > from a loaded organic phase are realized. The purity of the raffinate Li solution is relatively high, so that the subsequent preparation of battery-grade lithium carbonate is facilitated. The strip liquor can be recycled for multiple times, an iron intermediate is precipitated through pH adjustment, and the FePO4 product can be finally prepared through washing, aging and high-temperature calcination. The method is high in extraction selectivity, recyclable in process and mild in operation condition, has good separation effect and resource utilization efficiency, and is suitable for popularization and application of a Fe / Li separation process in lithium battery recovery.

To provide a method which enables inexpensive production with a high yield of lithium hydroxide with a low amount of impurities such as sodium from lithium-containing water including a lithium ion and a chloride ion.SOLUTION: A production method of lithium hydroxide includes: a crystallizing step of crystallizing lithium hydroxide (LiOH) from lithium-containing water including a lithium ion and a chloride ion; a solid-liquid separation step of performing solid-liquid separation treatment of concentrated liquid including the LiOH to obtain the LiOH as a solid product and filtrate; a carbonation step of producing lithium carbonate from the filtrate by carbonation; a lithium carbonate recovery step of evaporating at least a part of ammonia from a mixed liquid obtained in the carbonation step and performing solid-liquid separation treatment of the resultant treated liquid to obtain lithium carbonate as a solid product; a lithium hydroxide production step of converting the obtained lithium carbonate into LiOH followed by solid-liquid separation treatment to obtain an aqueous LiOH solution (1) as a liquid component; and a recrystallizing step of crystallizing LiOH from the aqueous solution (1).SELECTED DRAWING: Figure 2

The invention relates to a method for recycling aluminum, iron and lithium from waste lithium iron phosphate batteries. The method comprises the following steps: firstly, separating a positive electrode material of a waste battery cell, removing a binder through high-temperature treatment, adding the positive electrode material into a NaOH solution and a viscous liquid cosolvent, finally stirring and dissolving, neutralizing and adjusting the pH value through sulfuric acid, and precipitating and recovering aluminum; then sulfuric acid is matched with hydrogen peroxide, residual filter residues are stirred and dissolved, the pH value is adjusted in multiple steps, iron and lithium are precipitated respectively, and Fe (OH) 3 and Li2CO3 precipitates are obtained in sequence; the viscous liquid cosolvent disclosed by the invention is prepared from 1-aminoethyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imine salt and boric acid powder; the recovery rate of aluminum, lithium and iron is high, the recovery cost is low, and the economic value is high.

The invention provides a chlorine-resistant high-flux salt lake lithium extraction separation membrane and a preparation method, and belongs to the technical field of salt lake lithium extraction membrane separation.The preparation method specifically comprises the following steps that 1, a hollow fiber base membrane is prepared, specifically, a polymer, a solvent and an additive are mixed to form a membrane casting solution, and the hollow fiber base membrane is prepared through a spinning technology; step 2, modifying a piperazine monomer, and reacting the piperazine monomer with bis (2-chloroethyl) amine to generate a piperazine monomer with a spiral structure; 3, interfacial polymerization: the base membrane is sequentially immersed in a modified piperazine monomer solution and a trimesoyl chloride (TMC) solution for interfacial polymerization reaction, a thin spiral net structure functional separation layer is formed, and the formed nanofiltration membrane has the performance of chlorine resistance, high flux, high selective separation and the like. The key problems of low Mg < 2 + > / Li < + > separation efficiency, poor chlorine resistance of the membrane, insufficient flux and the like in lithium extraction from the salt lake are solved, the lithium recovery rate is remarkably increased, and the service life of the membrane is remarkably prolonged.

The invention relates to a waste lithium iron phosphate battery positive electrode material leaching recovery method capable of improving the lithium ion leaching rate. The method comprises the following steps: adding the positive electrode material of the waste lithium iron phosphate battery into deionized water, heating, adding hydrogen peroxide, adjusting the pH value by using a concentrated sulfuric acid solution, soaking, and filtering to obtain a Li < + >-containing solution and a filter cake containing FePO4; adding hydrogen peroxide and an oxidation catalyst into the low-concentration Li < + >-containing solution, heating, filtering to remove the catalyst, adjusting the pH value by using a concentrated sulfuric acid solution, soaking, and filtering to obtain a high-concentration Li < + >-containing solution and a filter cake containing FePO4; adding NaOH into the high-concentration Li < + >-containing filtrate to remove impurities, then adding Na2CO3, and precipitating to obtain crude lithium carbonate; the method comprises the following steps: repeatedly cleaning crude lithium carbonate with boiling water to obtain a Li2CO3 product; the method can effectively improve the lithium ion leaching rate.

The invention provides a production method and device for preparing battery-grade lithium carbonate through continuous lithium deposition. The production method for preparing the battery-grade lithium carbonate through continuous lithium precipitation comprises the following steps that S1, a lithium-containing solution is prepared, brine prepared from lithium ore is subjected to purification and resin impurity removal to obtain the lithium-containing solution, and then the lithium-containing solution is put into a container and heated to 95 DEG C or above through water bath for standby application; s2, preparing a carbonate solution; S3, continuously precipitating lithium; s4, suction filtration and water washing. According to the production method for preparing the battery-grade lithium carbonate through continuous lithium deposition, a solution required by lithium deposition is pumped into the microtube jet high-shear mixer through an external peristaltic pump and other devices for reaction to generate lithium carbonate slurry, and then the particle size of the lithium carbonate is controlled through multiple shear layers in the microtube jet high-shear mixer; and the peritectic problem generally existing in lithium carbonate production is reduced, and the impurity content is reduced, so that the purpose of continuously depositing the battery-grade lithium carbonate is achieved.

The present invention provides a method for stepwise recovering lithium and rare earths from rare earth molten salt electrolysis slag, belonging to the technical field of metallurgical waste slag treatment and secondary resource recycling. The method comprises the following steps: (1) reacting the rare earth molten salt electrolysis slag with sulfuric acid for leaching to obtain a lithium-containing solution and a leaching residue; (2) mixing the leaching residue with an additive for low-temperature roasting transformation to obtain a roasting product; (3) performing water leaching on the roasting product to obtain a water leaching residue; (4) performing acid leaching on the water leaching residue and adding a reducing agent to obtain a rare earth leaching solution and a leaching residue; wherein, the additive is an alkali and activated carbon, and the reducing agent is formaldehyde or hydrogen peroxide. The method of the present invention realizes the mineral phase transformation and efficient extraction of lithium and rare earths in the rare earth molten salt electrolysis slag, realizes the separation of lithium and rare earths, and at the same time, fluorine can be recovered, having the advantages of high extraction rates of lithium and rare earths and being green.

The invention relates to the technical field of environmental protection, and discloses a method for degrading formamide organic wastewater and recycling key metals of a retired lithium ion battery. The method comprises the following steps: S1, obtaining the positive electrode material of the retired lithium ion battery, mixing the positive electrode material with formamide organic wastewater, and carrying out hydrothermal reaction to obtain a leachate; s2, adjusting the pH value of the leachate to 6-14, and carrying out a transition metal precipitation reaction to obtain a transition metal hydroxide precursor and a lithium-rich filtrate; and S3, adding a sodium carbonate solution into the lithium-rich filtrate, carrying out a precipitation reaction, and collecting lithium carbonate. The formamide organic wastewater serves as an endogenous reducing agent, deep degradation of the formamide organic wastewater is achieved under the hydrothermal condition, efficient leaching of key metal in the retired lithium ion battery is achieved, and waste is treated with waste; the formamide degradation efficiency can reach 90% or above, and the defects that an existing formamide wastewater treatment method is high in energy consumption, large in reagent consumption, high in cost, low in degradation efficiency and large in environmental treatment pressure are overcome.

The invention relates to the technical field of recovery and regeneration of waste lithium ion battery materials, in particular to a method for synchronously realizing selective extraction of lithium and direct regeneration of iron phosphate. The method comprises the following steps: providing positive electrode powder of the waste lithium iron phosphate battery; a hydrogen bond donor and a hydrogen bond acceptor are mixed, heated and stirred to obtain the eutectic solvent, the hydrogen bond donor is one or more of formic acid, acetic acid, propionic acid, pyruvic acid, phytic acid and citric acid, and the hydrogen bond acceptor is ethylene glycol; adding water into the deep-eutectic solvent for dilution, then adding the positive electrode powder and an oxidizing agent, heating and stirring, and filtering to obtain a lithium-containing leaching solution and leaching residues; carrying out concentration treatment and impurity removal treatment on the lithium-containing leachate, and then adding a saturated sodium carbonate solution to carry out lithium precipitation reaction to obtain lithium carbonate; and calcining the leaching residues to obtain iron phosphate. According to the method, the specific eutectic solvent is adopted to treat the positive electrode powder of the waste lithium iron phosphate battery, and selective extraction of lithium and direct regeneration of iron phosphate can be synchronously realized under mild conditions.

The invention belongs to the field of metal recovery through an electrolytic method, and discloses an electrolytic recovery and reutilization method of a waste lithium-rich manganese-based positive electrode material, which comprises the following steps: firstly, carrying out electric field driven lithium removal on the lithium-rich manganese-based positive electrode material of a waste lithium ion battery through an electrolytic method, and then annealing the lithium-rich manganese-based positive electrode material after lithium removal, the manganese-based composite oxide capable of being used as the water-based zinc ion battery positive electrode material is obtained; and precipitating and recycling the removed Li ions by adding a precipitating agent. According to the method disclosed by the invention, the manganese-based composite oxide which can be used as an aqueous zinc ion battery positive electrode material is obtained while the lithium element is effectively recovered, and the process is simple, easy to implement and beneficial to popularization and application.

The invention discloses a method for converting lithium hydroxide into lithium carbonate. The method comprises the following steps: S1, preparing or taking a lithium hydroxide solution and a carbonate solution; s2, putting the lithium hydroxide solution and the carbonate solution into electrodialysis equipment, and carrying out electrodialysis treatment; and S3, after electrodialysis is finished, collecting a lithium carbonate solution, and sequentially carrying out lithium precipitation and solid-liquid separation on the lithium carbonate solution to obtain the battery-grade lithium carbonate. According to the method for converting lithium hydroxide into lithium carbonate disclosed by the invention, CO2 is replaced by carbonate, so that the generation of lithium bicarbonate is avoided, the lithium carbonate and the byproduct alkali liquor are directly obtained, the raw material source is wide, the preparation condition is mild, the production cost is greatly reduced, and the method has huge potential economic benefits.

The invention relates to a method for selectively leaching and regenerating a positive electrode material from a waste lithium ion battery, and belongs to the technical field of lithium ion batteries. The method comprises the following steps: discharging, disassembling, crushing, calcining and screening the waste lithium ion battery, adding an obtained positive active material into an oxalic acid solution, and stirring and reacting at 60-80 DEG C under the irradiation of an ultraviolet lamp to obtain a leaching solution rich in metal elements and leaching residue iron phosphate; adding sodium carbonate into the leachate for reaction to obtain lithium carbonate; and ball-milling and mixing iron phosphate, lithium carbonate and a carbon source, drying and calcining to obtain the regenerated lithium iron phosphate positive electrode material. The oxalic acid system is catalyzed by ultraviolet light to generate hydroxyl free radicals with strong oxidizing property, so that the leaching efficiency of lithium is remarkably improved, and the dissolution of iron is inhibited, thereby realizing the efficient separation of lithium and iron. The leaching residue is high-purity iron phosphate, lithium in the leaching solution is recycled in the form of lithium carbonate, and the leaching residue and the lithium carbonate can be directly used for regenerating the lithium iron phosphate positive electrode material as precursors, so that the technological process is greatly simplified, and the production cost is reduced.

The invention relates to the technical field of lithium battery materials, in particular to a method for preparing battery-grade lithium carbonate from waste lithium batteries. The method comprises the following steps: disassembling, crushing and sieving a recycled lithium iron phosphate battery to obtain a crushed lithium battery material; a choline chloride-citric acid mixed solution is adopted to conduct leaching treatment on the crushed materials, and sulfuric acid is added to inhibit leaching of iron and phosphorus ions; filtering to obtain a first filtrate and a first filter residue; adding calcium hydroxide into the first filtrate, and filtering to obtain second filtrate and second filter residues; adsorbing the second filtrate with activated carbon to remove impurities, and filtering to obtain a third filtrate and a third filter residue; adding hydrochloric acid into the third filtrate to obtain a lithium chloride solution; carbonizing and converting the lithium chloride solution into a lithium carbonate solution; and carrying out gradient crystallization treatment on the lithium carbonate solution, pulping with pure water, and drying to obtain the high-purity lithium carbonate finished product. The method overcomes the problems of low lithium recovery rate, complex process, low lithium carbonate purity, large crystal particle size, more impurities and the like of the existing lithium iron phosphate battery.

The invention discloses a continuous crystallization separation method for improving the recovery rate of sodium chloride and lithium chloride through mother liquor circulation. The method comprises the following steps: continuously feeding a raw material solution into a mixing tank to be mixed with a circulating solution, continuously feeding the mixed solution into a lithium chloride reaction crystallization device, feeding crystallized turbid liquid into a continuous centrifugal device from a crystallizer, carrying out solid-liquid separation, feeding a solid lithium carbonate product into a subsequent drying device, and carrying out vacuum drying at 30-40 DEG C for 5-6 hours, the method comprises the following steps: centrifugally separating a lithium-rich solution, performing evaporative crystallization and concentration on the centrifugally separated mother solution, feeding crystallized turbid liquid into a continuous centrifugal device from a crystallizer, performing solid-liquid separation, feeding a solid sodium chloride product into a subsequent drying device, performing vacuum drying for 5-6 hours at 30-40 DEG C, refluxing the concentrated lithium-rich solution into a mixing tank, and performing continuous recovery through mother solution circulation.

The invention discloses a spodumene concentrate resourceful treatment method which comprises the following steps: carrying out wet treatment on spodumene acid clinker to prepare lithium-removed filter residues and leachate; carrying out neutralization treatment and desulfurization treatment on the leachate to obtain a lithium-containing purified solution, gypsum and iron oxide red, and carrying out lithium extraction treatment on the lithium-containing purified solution to obtain a lithium salt and mirabilite; the lithium-removed filter residues are treated through a process combining a beneficiation method and a chemical method, and water glass, nano kaolinite, ceramsite aggregate and tantalum-niobium concentrate are obtained. According to the method, whole-process slag-free production of the spodumene concentrate is achieved, and meanwhile the lithium-containing compound with the high purity and the high quality is obtained; and various valuable products can be obtained.

The invention belongs to the field of waste resource recovery treatment, and provides a method for combined recovery of lithium iron phosphate and ternary battery powder, which comprises the following steps: mixing and grinding decommissioned lithium iron phosphate and ternary battery powder, partially oxidizing lithium iron phosphate, then carrying out acid leaching, adding an oxidizing agent and a specific oxidation accelerator La2O3-LaF3 in the leaching process, and carrying out acid leaching to obtain lithium iron phosphate and ternary battery powder; carrying out heating reaction on the obtained leached slurry to obtain a lithium extraction solution, and then removing impurities to obtain a pure lithium solution; the impurity removal comprises the following steps: removing fluorine by using lanthanum salt to obtain lanthanum fluoride slag, and recycling the obtained lanthanum fluoride slag as an oxidation accelerant. Lithium iron phosphate is partially oxidized into more stable iron phosphate and lithium oxide by utilizing the oxidability of ternary battery powder, complete oxidation of lithium iron phosphate is effectively promoted by matching with an oxidation accelerator La2O3-LaF3 selected in the acid leaching process, use of hydrogen peroxide is avoided, LaF3 can be regenerated for use through the rear-end comprehensive impurity removal process, the resource utilization rate is increased, and the production cost is reduced. And the economic cost is reduced.

The invention discloses a method for preparing a battery-grade lithium compound. The method comprises the following steps: S1, carrying out sulfuric acid acidification reaction on a lithium-containing raw material or roasting by adding sulfate, and carrying out water leaching to obtain leached slurry; the lithium-containing raw material is a lithium mineral or a waste lithium battery material; s2, calcium oxide or calcium hydroxide is added into the leaching slurry, filtering is performed after full reaction, filtrate A and filter residues A are obtained, the main component of the filtrate A is lithium hydroxide, and the filtrate A further comprises soluble impurities formed after water leaching; s3, adding a substance for removing calcium ions into the filtrate A, fully reacting, and filtering to obtain filtrate B and filter residues B; s4, fully contacting the filtrate B with an extracting agent for extraction, and then separating to obtain a loaded organic phase and raffinate; s5, reversely extracting the loaded organic phase to obtain a lithium solution and a blank organic phase; and S6, further treating the lithium solution to obtain the battery-grade lithium compound. Sodium ions are basically not introduced, the energy consumption is low, the process is simplified, the product quality is high, the production cost is low, the lithium yield is high, and byproducts are convenient to treat.

The invention belongs to the technical field of lithium battery material recovery, and particularly relates to a method for recovering a waste lithium iron phosphate positive electrode material. The method comprises the following steps: (1) grinding and sieving the positive electrode material of the waste lithium iron phosphate battery, mixing with an alkaline solution, stirring and leaching, and carrying out solid-liquid separation to obtain a lithium-rich solution and leaching residues; (2) introducing a saturated sodium carbonate solution into the obtained lithium-rich solution, carrying out heating reaction, filtering, taking a solid phase, and drying to obtain lithium carbonate; and the obtained leaching residues are dried, and ferroferric oxide is obtained. According to the method, the waste lithium iron phosphate battery positive electrode material is leached through the alkaline liquid phase, it can be guaranteed that lithium and iron in waste lithium iron phosphate are separated through a one-step leaching method, and therefore selective lithium extraction is achieved. The whole technological process is convenient to operate, mild in reaction condition and low in energy consumption, does not need to use any acid or oxidant, avoids generation of a large amount of waste liquid and harmful gas, and is high in selective lithium extraction efficiency.

The invention relates to a method for preparing battery-grade lithium carbonate with uniform granularity, which comprises the following steps: pulping a lithium-containing raw material to obtain raw material slurry; introducing carbon dioxide into the raw material slurry, and carrying out carbonization treatment until the solution is clear, so as to obtain carbonized clear liquid; and mixing the carbonized clear liquid, a particle size regulator and a particle size regulating auxiliary agent, and then sequentially carrying out pyrolysis treatment, solid-liquid separation and drying to obtain the battery-grade lithium carbonate. According to the method provided by the invention, battery-grade lithium carbonate with relatively concentrated particle size distribution can be obtained without adopting a crushing step, and impurities of a finished product meet standard requirements.

The invention provides a method for extracting lithium from sulfate subtype salt lake original brine and application, and belongs to the field of salt lake lithium extraction.The method for extracting lithium from sulfate subtype salt lake original brine comprises the following steps that the sulfate subtype salt lake original brine is subjected to pretreatment and nanofiltration treatment, and low-sulfate-radical brine and high-sulfate-radical brine are obtained; the low-sulfate-radical brine is subjected to desorption after being treated by an aluminum-series lithium adsorbent, and a first desorption solution is obtained; the high-sulfate-radical brine is desorbed after being treated by a titanium-series lithium adsorbent, and a second desorption solution is obtained; the first desorption solution and the second desorption solution are sequentially subjected to RO membrane concentration, multi-stage nanofiltration, electrodialysis concentration, evaporation concentration, resin impurity removal and lithium precipitation treatment, and the battery-grade lithium carbonate is obtained. The nanofiltration treatment is small in operation pressure and low in energy consumption; and the obtained low-sulfate-radical brine and high-sulfate-radical brine are respectively treated by adopting proper adsorbents according to different sulfate radical concentrations so as to efficiently recover lithium, so that the lithium yield is improved, the operation is simple, and the obtained battery-grade lithium carbonate is high in purity and excellent in performance.

The invention discloses an acid leaching device for extracting lithium carbonate based on a waste lithium battery, and relates to the technical field of waste lithium battery treatment, the acid leaching device comprises an acid leaching barrel, and further comprises a leaching promoting mechanism mounted in the acid leaching barrel and used for rapidly mixing acid liquor with lithium battery positive electrode material powder; the filtering mechanism is mounted outside the immersion promoting mechanism and is used for filtering solid impurities in the lithium battery positive electrode material powder; the impurity removing mechanism is arranged above the filtering mechanism and is used for cleaning solid impurities; according to the acid leaching device for lithium carbonate extraction based on the waste lithium battery, solid impurities are removed out of a reaction system in time through the filter plate, the risk that the solid impurities are dissolved in acid liquor or coprecipitated with lithium salt is reduced, the purity of lithium carbonate leaching is improved, and in the up-and-down reciprocating movement process of the filter plate, through the back flushing action, the acid leaching efficiency is improved. The filter plate is prevented from being blocked, and the filtering smoothness is kept.

The invention discloses a treatment method of a lithium extraction leachate and a production method of lithium carbonate, wherein the treatment method can be used for efficiently recycling an aluminum resource in the leachate. The treatment method of the lithium extraction leachate comprises the following steps that 100, potassium sulfate is added into the lithium extraction leachate, and first liquid is obtained after the potassium sulfate is dissolved; step 200, performing freezing crystallization and solid-liquid separation treatment on the first liquid to obtain crude alum and lithium extraction mother liquor; step 300, dissolving crude alum in a solvent to obtain a second liquid; step 400, performing freezing crystallization and solid-liquid separation treatment on the second liquid to obtain high-purity alum and filtered mother liquor; wherein at least one of the lithium ion concentration, the rubidium ion concentration and the cesium ion concentration in the filtered mother liquor serves as a monitoring object to be monitored, when the monitoring object is larger than or equal to a threshold value, the filtered mother liquor and the lithium extraction mother liquor are mixed, and when the monitoring object is smaller than the threshold value, the filtered mother liquor serves as a solvent of crude alum.

The invention relates to a method for efficiently extracting high-specification battery-grade lithium carbonate, and belongs to the technical field of lithium carbonate preparation. The method comprises the following steps: pretreatment: mixing a lithium-containing solution raw material with liquid caustic soda; extraction: fully mixing the lithium-containing solution with a no-load extraction agent, and performing phase splitting; reverse extraction: conveying sulfuric acid with a certain concentration and a lithium-containing load oil phase through a centrifugal pump respectively, fully mixing in an extraction tank, and splitting phases; calcium and magnesium are removed from the strip liquor, specifically, the strip liquor is adsorbed through resin, calcium and magnesium in the strip liquor are adsorbed and removed, and the resin is recycled through acid-base regeneration and water washing after adsorption saturation; wastewater treatment: firstly recycling an organic extracting agent in a non-dissolved state from the water-phase raffinate in the extraction procedure through an oil separator, and then treating and regenerating through a macroporous resin adsorption tank; precipitating lithium: placing the prepared sodium carbonate solution in a beaker, stirring and heating, slowly dropwise adding the lithium sulfate solution, continuously reacting, and filtering; and washing and drying: filtering, and drying the lithium carbonate obtained after filtering.