151results about "Lithium sulfates/sulfites" patented technology

The present application discloses a method for recovering battery-grade iron phosphate and lithium salts from lithium iron phosphate waste materials and its application, comprising the following steps: S100, dissolving the lithium iron phosphate waste materials with a phosphoric acid solution, filtering to obtain a waste material dissolution solution; S200, adding an acid solution and an oxidant to the waste material dissolution solution to obtain a crystallization stock solution; S300, diluting the crystallization stock solution with water until its pH value is 1.0 to 1.5, and performing high-temperature crystallization to obtain hydrated iron phosphate and a lithium-containing filtrate; S400, roasting the hydrated iron phosphate to obtain battery-grade iron phosphate; S500, removing water from the lithium-containing filtrate to obtain solution a, circulating solution a to dissolve the lithium iron phosphate waste materials, and concentrating to obtain lithium salts. The present application uses a phosphoric acid solution as the leaching solvent, does not require the use of an alkali solution subsequently and can be leached cyclically, improving the economic benefits while enabling the efficient recovery of all elements of Li, Fe, and P, and also capable of obtaining a battery-grade iron phosphate product with an iron-to-phosphorus ratio meeting the requirements.

The invention discloses a method for separating and recycling phosphorus, iron and lithium in battery black powder, and relates to the technical field of battery recycling. The method comprises the following steps: carrying out acid leaching on battery black powder to obtain a battery black powder leaching solution and filter residues; an oxidizing agent is added into the battery black powder leaching solution, the pH of the solution is adjusted to 1.8-2.5, solid-liquid separation is conducted after the reaction is completed, and iron phosphate sediment and a lithium-containing solution are obtained; adjusting the pH value of the lithium-containing solution to 10-12, and carrying out solid-liquid separation after the reaction is completed to obtain a metal precipitate and a lithium sulfate solution; dissolving the iron phosphate precipitate in a sulfuric acid solution, adding a reducing agent to reduce ferric iron into ferrous iron, separating out ferrous sulfate by adopting an alcohol precipitation method or an ammonium sulfate crystallization method, and performing solid-liquid separation after the reaction is completed to obtain ferrous sulfate precipitate or ammonium ferrous sulfate crystals and mother liquor; and evaporating and concentrating the mother liquor, and extracting to obtain a phosphoric acid solution. According to the method, the three elements of phosphorus, iron and lithium in the battery black powder can be recycled, and the environmental problem caused by stacking of the lithium extraction slag can be avoided.

The invention discloses a method for preparing high-purity lithium sulfide from a lithium sulfate mother liquor, which comprises the following steps: preparing a lithium sulfate concentrated liquor: adding 98% concentrated sulfuric acid into the lithium sulfate mother liquor to adjust the pH value, adjusting the pH value to 6-7, carrying out precise filtration to filter out possible impurities to obtain a filtrate, introducing the filtrate into an MVR evaporation system, and concentrating the mother liquor to obtain a concentrated liquor, performing freezing crystallization on the concentrated solution by using a cooling crystallizer, and then performing centrifugal separation under the action of a centrifugal machine to obtain solid slag which is mirabilite and a solution which is lithium sulfate concentrated solution; and preparing crude lithium sulfide: performing evaporative crystallization on the obtained lithium sulfate concentrated solution, adding pure water for slurrying, and performing centrifugal filtration and cleaning for 2-3 times. The impurity content is effectively controlled through a multi-stage purification process, the Li2S product with the purity larger than or equal to 99.95% is finally obtained, the key technical problem of direct conversion from a liquid battery recycling material to a solid battery positive electrode raw material is solved, and core material support is provided for lithium battery industry closed loop and industrial product iteration.

The invention discloses a green roasting method for recycling desulfurized gypsum, and belongs to the technical field of solid waste recycling. According to the process disclosed by the invention, the desulfurized gypsum solid waste rich in calcium sulfate is used for replacing part or all of sulfate to be mixed with lepidolite for roasting reaction, and components such as calcium carbonate and calcium sulfite contained in the desulfurized gypsum are utilized by controlling the step-by-step heating rate and the roasting temperature; under specific roasting process conditions, calcium oxide and calcium sulfide generated through self-reaction serve as purifying agents and react with fluorine and thallium to form stable calcium fluoride and thallium sulfide precipitates, fluorine and thallium are fixed in the high-temperature roasting stage, the pressure of follow-up flue gas treatment and wastewater treatment is effectively reduced through self-purification, and environmental pollution is reduced.

The utility model discloses a device for recovering and separating potassium and sodium salts generated in the process of extracting lithium from ore, which is characterized in that an outlet of a salt dissolving tank is connected with a freezing buffer tank, an outlet of the freezing buffer tank is connected with a freezing crystallizer, a freezing crystal slurry outlet is connected with a freezing thickener, and an outlet of the freezing thickener is connected with a freezing centrifuge; a refrigerated centrifugal solid phase outlet is connected with a hot melting tank, a bottom outlet of the hot melting tank is connected with an anhydrous sodium sulphate crystallizer, an anhydrous sodium sulphate crystal slurry outlet is connected with an anhydrous sodium sulphate thickener and an anhydrous sodium sulphate centrifuge, and a centrifugal solid phase outlet is connected with an anhydrous sodium sulphate discharge pipe; the centrifugal liquid phase outlet is connected with an anhydrous sodium sulphate mother liquor tank; a liquid phase outlet of the freezing centrifuge is connected with a freezing mother liquor tank, freezing mother liquor flows back and enters the potassium sulfate crystallizer, a potassium sulfate crystallization magma outlet is connected with the potassium sulfate thickener and the potassium sulfate centrifuge, and a potassium sulfate centrifugal solid phase outlet is connected with a potassium sulfate salt discharge pipe. The device can be used for separating the mixed salt into sodium sulfate with extremely high purity and potassium sulfate with relatively high purity, so that the product yield is improved.

Embodiments relate to methods and processes for purification of lithium containing brines by selectively separating boron containing compounds. The method includes passing a feed brine including lithium and at least one boron compound through at least one semi-permeable membrane in which the boron compounds are separated from the lithium by preferentially passing the boron compounds through the membrane stage(s). At least one environmental condition of the feed brine and / or membrane stage(s) may be modified to allow boron compounds to be preferentially passed through the membrane stage(s). The lithium-rich concentrate stream may be further purified and / or converted into lithium products, while the resultant boron-rich permeate stream (including the separated boron containing compounds) may be further processed.

The utility model relates to the technical field of coating devices, and discloses separation equipment for lithium sulfate solution production, which comprises a separation equipment body and a feed port fixedly connected to the top of the separation equipment body, and further comprises a discharge pipe fixedly connected to the bottom of the separation equipment body, a control chamber is fixedly connected to the bottom of the reaction chamber and communicates with the feeding port, a sealing plate is fixedly connected to the interior of the control chamber, and a quantity control mechanism is further arranged in the separation equipment body. Through the arrangement of the reaction chamber, the control chamber and the sealing plate, the effect of conveniently controlling the quantity of a lithium sulfate solution by a worker is achieved, the subsequent separation effect is improved, and the problem that in the using process of existing separation equipment, the lithium sulfate solution is often directly poured into a separation net at a time, and the separation efficiency is affected is solved. And the problem that the separation effect is poor due to the fact that too much liquid is poured at a time is possibly solved.

The utility model discloses an evaporation and concentration system suitable for lithium sulfate purification, which is characterized in that an outlet of a raw material tank is sequentially connected with a cold side of a condensate water preheater and a cold side of a non-condensable steam preheater through an outlet of a feeding pump, and then is connected with a tube pass inlet of a heater together with an outlet pipeline of a material circulating pump; a tube pass outlet of the heater is connected with a material inlet of the integrated separator, and a material outlet of the separator is connected with an inlet of the material circulating pump; a secondary steam outlet of the integrated separator is connected with an inlet of a steam compressor through a scrubber tower, and a compressed steam pipe is connected with a shell pass steam inlet of a heater; a shell pass condensed water outlet of the heater is connected with an inlet of a condensed water tank; an outlet of the condensed water tank is connected with a hot side of the condensed water preheater through a condensed water pump; a shell pass extraction opening of the heater is connected with the hot side of the non-condensable steam preheater through a non-condensable gas conveying pipe, and a hot side outlet of the condenser is connected with a vacuumizing system. The system is high in evaporation efficiency and low in operation cost and equipment investment.

Embodiments herein relate to recycling of used lithium battery materials. In some aspects, a method may include suspending a lithium source in a solvent containing an oxidizing agent to extract lithium, forming an extracted lithium solution, separating the extracted lithium solution from residual solids of the lithium source, purifying the extracted lithium solution by precipitating and filtering impurities, and precipitating lithium in the purified lithium solution to produce lithium carbonate (Li2CO3). In some embodiments, the method may also include pre-treating the lithium source to improve the kinetics of the lithium extraction. In some embodiments, the pretreatment may include a cutting or comminution step to reduce the size of the lithium source. In some embodiments, the lithium source may include lithium ion battery waste. In some embodiments, the oxidizing agent may include sodium persulfate (Na2S2O8), potassium persulfate ((NH4) 2S2O8), ammonium persulfate (NH4) 2S2O8, hydrogen peroxide (H2O2), ozone (O3), and / or nitrous oxide (N2O).

Embodiments described herein relate to recycling of spent lithium battery material. In some aspects, a method can include suspending a lithium source in a solvent containing an oxidation reagent to extract lithium, forming an extracted lithium solution, separating the extracted lithium solution from residual solids of a lithium source, purifying the extracted lithium solution by precipitating and filtering impurities, and precipitating the lithium in the purified lithium solution to generate lithium carbonate (Li2CO3). In some embodiments, the method can further include preprocessing the lithium source to improve kinetics of the lithium extraction. In some embodiments, the preprocessing can include a cutting or shredding step to downsize the lithium source. In some embodiments, the lithium source can include lithium-ion battery waste. In some embodiments, the oxidation reagent can include sodium persulfate (Na2S2O8), potassium persulfate (K2S2O8), ammonium persulfate (NH4)2S2O8, hydrogen peroxide (H2O2), ozone (O3), and / or nitrous oxide (N2O).

The present invention relates to the technical field of batteries, and specifically to a cathode material and a preparation method therefor and use thereof. A cathode material, including a cathode bulk and a coating layer coated on at least part of a surface of the cathode bulk, where a chemical formula of the cathode bulk is LiaNixCoyMnzMbO2, where 0.97≤a≤1.1, 0.5≤x<1.0, 0<y≤0.1, 0<z≤0.1, and x+y+z+b=1, and an ion M in the cathode bulk is at least one selected from Sb5+, Ti4+, Zr4+, V5+, Nb5+, W6+ and Mo6+; and the coating layer includes Li2SO4. The cathode material in the present invention has low residual alkali on a surface and good structural stability, and can improve cycle performance and safety performance of batteries.

The invention provides a method for preparing high-purity lithium sulfate from a lithium-sodium mixed solution. The method comprises the following steps: providing a lithium-sodium mixed sulfate solution; the method comprises the following steps: based on a Li2SO4-Na2SO4-H2O ternary system phase diagram, evaporating and concentrating a lithium-sodium mixed sulfate solution to be saturated, and then freezing and denitrifying to obtain a denitrified solution; evaporating the denitrated solution to a co-saturation point of lithium-sodium mixed sulfate, carrying out lithium precipitation, and separating to obtain a lithium precipitation mother solution and a lithium sulfate monohydrate crude product; purifying the lithium sulfate monohydrate crude product to obtain a high-purity lithium sulfate product; freezing and crystallizing the lithium precipitation mother solution, and separating to obtain a lithium-sodium mixed sulfate hydrate and a frozen solution; the lithium-sodium mixed sulfate hydrate is returned to the lithium-sodium mixed sulfate solution, and the frozen liquid is returned to the denitrated liquid. According to the method, the process is simplified, the lithium recovery rate is increased, cost reduction and efficiency improvement are achieved, material recycling can be achieved in the whole process, and the development prospect is good.

The present invention discloses a refined lithium sulfate and its production process, belonging to the technical field of producing refined lithium sulfate. The production process of the refined lithium sulfate of the present invention includes high-temperature roasting, acidification, low-temperature roasting, leaching with water, stepwise adjusting the pH value, adding a impurity remover, solid-liquid separation and pressure filtration, and finally obtaining refined lithium sulfate, wherein the impurity remover is cellulose nanocrystal composite non-ionic PAM. By setting different pH values step by step and combining with the action of the impurity remover, the zonal flocculation and sedimentation removal of impurity particles can be realized, thereby improving the removal efficiency of impurity ions and helping the complete removal of impurity ions. The non-ionic PAM uses cellulose nanocrystals as a carrier, which can improve the mechanical strength and structural stability of the impurity remover, enhance the attraction and capture ability of the impurity remover for impurity particles, optimize the pH adaptability of the impurity remover, and efficiently remove impurity particles.

The present specification provides a method for preparing a solid electrolyte for a secondary battery, comprising the steps of: (S1) preparing a material composition comprising phosphorus (P) sulfide, a lithium halide and lithium sulfide; (S2) mechanically milling the material composition in a milling container; and (S3) calcining a compound obtained after the milling step, wherein the calcination step (S3) performs purging using gas.

This invention provides a method and apparatus for lithium recovery from a high-sodium, low-lithium solution via cryogenic sodium precipitation and targeted extraction. The method comprises the following steps: S1, weighing sodium sulfate and lithium sulfate samples, dissolving them in deionized water to prepare a high-sodium, low-lithium solution; S2, determining the lithium and sodium ion content of the high-sodium, low-lithium solution using ICP-MS and atomic absorption spectroscopy; S3, freezing the high-sodium, low-lithium solution prepared in step S1 in a circulating freezer to obtain a solid-liquid mixture. The method and apparatus provided by this invention achieve low lithium carryover during sodium precipitation from a high-sodium, low-lithium solution, further realizing high-efficiency lithium resource recovery. Compared with traditional processes, the lithium carryover rate during sodium precipitation can be reduced to 0.2%, reducing energy consumption and operational difficulty while improving lithium recovery rate, making it suitable for industrial production.

The present invention relates to the technical field of batteries, and specifically relates to a positive electrode material and a preparation method therefor and a use thereof. A positive electrode material, comprising a positive electrode matrix and a coating layer applied on at least part of the surface of the positive electrode matrix. The chemical formula of the positive electrode matrix is LiaNixCoyMnzMbO2, wherein 0.97≤a≤1.1, 0.50≤x＜1.0, 0＜y≤0.1, 0＜z ≤0.1, x+y+z+b＝1, and the ion M in the positive electrode matrix is selected from at least one of Sb5+, Ti4+, Zr4+, V5+, Nb5+, W6+ and Mo6+; and the coating layer contains Li2SO4. The positive electrode material has low surface residual alkali and good structural stability, and can improve the cycle performance and safety performance of a battery.

The invention discloses a method for extracting lithium sulfate from high-iron spodumene concentrate, which comprises the following steps: mixing high-iron spodumene concentrate, sulfate and carbonate, and processing to obtain powder; the mass ratio of the high-iron spodumene concentrate to the sulfate to the carbonate is 1: (0.3-0.8): (0.01-0.5); the powder is subjected to brick pressing forming, a powder green brick is obtained, and the powder green brick is dried and roasted at the temperature of 900-1050 DEG C; cooling and crushing the roasted powder green brick to obtain a roasted particle material; adding water into the roasted particle material, carrying out ball milling, and leaching to obtain a leaching solution and leaching residues; and carrying out purification and concentration treatment on the leachate to obtain the lithium sulfate. By implementing the method, the interference of iron impurities can be eliminated, and the cost is reduced while the lithium recovery rate is improved.

A method for producing battery-grade lithium dihydrogen phosphate using lithium-containing brine includes the following steps: (1) adding sodium hydroxide solution to lithium-containing mother liquor, adding the mixed solution to sodium dihydrogen phosphate solution, maintaining the pH of the system at 9-11, reacting, separating the solid and liquid phases to obtain lithium phosphate precipitate and mother liquor; (2) adjusting the slurry, adding concentrated sulfuric acid to react, separating the solid and liquid phases to obtain a mixed solution of liquid-phase lithium dihydrogen phosphate and lithium sulfate; (3) vacuum cooling and crystallization separation to obtain lithium dihydrogen phosphate crystals. This invention achieves efficient recovery of lithium ions from low-concentration lithium-containing brine, eliminating the need for conventional processes such as electrodialysis and MVR for further concentration of lithium-containing mother liquor. It also avoids the use of phosphoric acid in the acidification process, saving raw material costs, reducing the amount of water added in the acidification process, and reducing energy consumption in the crystallization separation process. The resulting battery-grade lithium dihydrogen phosphate is of stable quality, uniformly distributed, and bright white in color, suitable for preparing lithium-ion battery cathode materials, and has a low cost.

The invention discloses a lithium source impurity removal method, lithium phosphate and a preparation method thereof, and belongs to the technical field of battery materials. The invention solves the problem of how to provide a method for preparing high-purity lithium phosphate from a lithium source in lithium ore. The method comprises the step of removing impurities from a lithium source, and specifically comprises the following steps: roasting lithium ore, and leaching a product obtained after roasting to obtain a lithium sulfate solution; adding one or more of ammonia water, ammonia gas or liquid ammonia into the lithium sulfate solution to adjust the pH value to 8-11, and then filtering to obtain primary purified mother liquor; adding monoammonium phosphate or / and diammonium phosphate into the primary purified mother liquor, adjusting the pH value to 8-11 again, reacting under the stirring condition, and filtering to obtain secondary purified mother liquor; and adding EDTA (Ethylene Diamine Tetraacetic Acid) into the secondary purified mother liquor to obtain the lithium sulfate purified mother liquor. And adding one or more of ammonia water, ammonia gas or liquid ammonia into the monoammonium phosphate solution to adjust the pH value to 8-11, and adding the purified lithium sulfate mother liquor into the monoammonium phosphate solution to obtain the high-purity lithium phosphate.

The invention relates to a process for the production of lithium sulfide reduced in carbon impurity or free from carbon impurity, in which lithium sulfate and optionally lithium sulfit, lithium disulfate and / or other lithium sulfur oxides, and carbon impurity containing lithium sulfide are treated with hydrogen gas at temperautres in range from 300 to 600°C. The invention further relates to a lithium sulfide producible in this manner, the carbon impurity content of which is less than 2.0 % by weight, based on the weight of the lithium sulfide. This lithium sulfide is used for the production of battery components, preferably solid electrolytes, and solid-state batteries.

A method for producing a lithium solution according to the present disclosure comprises igniting a mixture of alpha-spodumene and metallic aluminum to cause a thermite reaction and bringing the reaction product into contact with a leaching agent to obtain a lithium solution. The leaching agent may be water or sulfuric acid. When the leaching agent is water, it is also possible to obtain a lithium solution by bringing water into contact with the reaction product without subjecting the reaction product to a sulfation treatment.

The utility model discloses a lithium carbonate production wet process section lithium recovery device which is characterized in that a lithium precipitation mother liquor pipe is connected with a circulating pipe of an MVR crystallizer, a salt leg outlet of the MVR crystallizer is connected with an MVR thickening tank, a bottom outlet of the MVR thickening tank is connected with an inlet of an MVR centrifugal machine, and a solid phase outlet of the MVR centrifugal machine is connected with an inlet of a salt leaching tank; a liquid phase outlet of the MVR centrifugal machine is connected with an MVR mother liquor tank, an outlet of the MVR mother liquor tank is connected with a reflux inlet of the MVR crystallizer and a feed inlet of the freezing crystallizer, a bottom outlet of the freezing crystallizer is connected with an inlet of the freezing thickening tank, and a bottom outlet of the freezing thickening tank is connected with an inlet of the freezing centrifugal machine; a liquid phase outlet of the freezing centrifugal machine is connected with a freezing mother liquor tank; a bottom outlet of the freezing mother liquor tank is connected with a circulating pipe of the freezing crystallizer and a lithium sulfate discharging pipe. The device can improve the lithium recycling rate, the sodium sulfate quality and the product stability, and reduce the energy consumption and the labor cost.

Provided is an all-solid-state secondary battery which includes a 3LiOH·Li2SO4-based solid electrolyte and is capable of significantly suppressing a reduction in lithium ion conductivity even after being held at high temperature for a long time. This all-solid-state secondary battery includes a solid electrolyte which is identified as 3LiOH·Li2SO4 by X-ray diffraction and further contains boron.

A process for producing alumina and a lithium salt comprising the steps of: (a) calcining an alpha spodumene ore or concentrate to produce beta spodumene; and (b) (I) leaching beta spodumene from the calcining step (a) with an alkaline solution under pressure; or (II) sulphating beta spodumene with at least sodium sulphate and leaching said sulphated beta spodumene to produce a lithium containing solution and a zeolitic residue. The lithium containing solution is treated to provide a purified lithium salt and said zeolitic residue is treated to provide high purity alumina.

The present application provides a method for recovering ternary black powder to prepare lithium salts, comprising the following steps: step S1: adding a reducing agent to the ternary black powder for roasting to obtain roasted black powder; step S2: adding water to the roasted black powder for water leaching, filtering to obtain a saturated lithium carbonate aqueous solution and undissolved solids; step S3: adding an inorganic acid to the saturated lithium carbonate aqueous solution until the pH is 6.5-7 to obtain a lithium salt aqueous solution; step S4: obtaining the lithium elution rate n of step S2, and determining, based on the lithium elution rate n, whether to wash the undissolved solids or continue to leaching the undissolved solids; step S5: obtaining the lithium salt saturation S of the lithium salt aqueous solution in step S3, and determining, based on the saturation S and the lithium elution rate n, whether to purify the lithium salt aqueous solution or to use the lithium salt aqueous solution as water for leaching in step S2. This method can produce a lithium salt product with high purity.

The present disclosure relates to a method for preparing a lithium compound, which comprises: preparing lithium phosphate; mixing the lithium phosphate and sulfuric acid to obtain a mixture; converting the lithium phosphate into lithium sulfate through a reaction in the mixture; and separating the lithium sulfate into a solid phase. In the step of converting the lithium phosphate into lithium sulfate through a reaction in the mixture, the total concentration ([P+S] mol / L) of phosphorus (P) and sulfur (S) in the liquid phase of the mixture is 5 mol / L or more.

The invention relates to the technical field of lepidolite extraction, in particular to a method for removing fluorine and chlorine from brine obtained by extracting lithium from lepidolite. A method for removing fluorine and chlorine from lepidolite lithium extraction brine comprises the following steps that S1, pretreatment is conducted, specifically, boric acid is added into the lepidolite lithium extraction brine, a sulfuric acid solution is added after sufficient and uniform mixing is conducted, the pH of the brine is adjusted to be 5-5.5, and pretreated brine is obtained; s2, fluorine and chlorine removal: the pretreated brine and a fluorine and chlorine removal extraction agent are mixed and then subjected to extraction treatment, a water phase and an oil phase are separated, the water phase is lithium extraction brine subjected to fluorine and chlorine removal, the fluorine and chlorine removal extraction agent comprises a composition extraction agent and isooctyl alcohol, and the composition extraction agent is composed of trioctyl methyl ammonium sulfate and trioctyl methyl ammonium chloride. The method has high selectivity and removal rate for chlorine and fluorine in the lithium extraction brine from lepidolite, and the lithium loss rate is relatively low.

A method for recycling lithium dihydrogen phosphate to treat lithium sinking mother liquor, comprising the following steps: (1) adding a mixed solution of lithium dihydrogen phosphate and lithium sulfate into the lithium sinking mother liquor to obtain lithium phosphate precipitate and low-lithium mother liquor; (2) separating the lithium phosphate precipitate obtained in step (1), then adding the lithium phosphate precipitate into a sulfuric acid solution to react, obtaining a mixed solution of lithium dihydrogen phosphate and lithium sulfate, and simultaneously precipitating lithium sulfate monohydrate crystals; (3) separating, washing and collecting the lithium sulfate monohydrate crystals obtained in step (2); and returning the mixed solution of lithium dihydrogen phosphate and lithium sulfate obtained in step (2) to step (1) for recycling. The method realizes high-content and low-impurity recovery of lithium ions in the lithium sinking mother liquor, consumes an amount of sulfuric acid equivalent to that consumed in the acidification process of the lithium sinking mother liquor, recycles phosphate, only needs to supplement the loss of dissolution, the lithium recovery rate reaches more than 95%, and secondary lithium sinking is not needed, thus simplifying the process and reducing the production cost.

A process (100) for treating aqueous impurity containing streams containing lithium cations and impurities within a lithium extraction process comprises: (a) contacting the impurity containing stream with a soluble phosphate to produce a precipitate containing lithium phosphate and a soluble impurity containing stream; and (b) treating the precipitate containing lithium phosphate with an aqueous reagent to produce the soluble phosphate for re-use in step (a) and a lithium salt recyclable to the lithium extraction process (100). Lithium recovery from the impurity containing stream may be 80% or greater.