924 results about "Lithium carbonate" patented technology

The invention discloses a fluoride salt-free nitrate-free cast iron enamel semitransparent glaze as well as a preparation method and application thereof, and belongs to the technical field of enamel. The semitransparent glaze is prepared from quartz, anhydrous borax, sodium carbonate, potassium carbonate, calcium carbonate, potassium feldspar, zinc oxide, lithium carbonate, zirconium silicate, titanium dioxide, aluminum oxide, trisodium phosphate, antimony oxide, magnesium carbonate and barium carbonate according to a specific mass ratio. The preparation method comprises the steps of raw material mixing, high-temperature melting under a pure oxygen condition, wiredrawing detection, quenching and the like. The semitransparent glaze is completely free of fluoride salt and nitrate, the problems of fluoride emission and environmental protection equipment blockage are avoided from the source, the fluorine content of the product is not detected through detection, the product meets the requirements of European Union REACH regulations, meanwhile, the product has good porcelain surface, luster and low-temperature firing adaptability, and is suitable for cast iron matrixes, the firing temperature is 740-760 DEG C, and the firing time is 2-3 hours. The method can be used for producing green and environment-friendly enamel products.

The invention relates to the technical field of retired ternary power battery recovery, and particularly discloses a method for preferentially extracting lithium and recovering valuable metals from a retired ternary lithium battery and application of the method. According to the method, the traditional process is broken through the preferential lithium extraction, and efficient recovery of lithium, Ni, Co and Mn is realized by utilizing'fast-medium-slow 'multi-stage cooperation of a composite reducing agent and accurate adaptation of roasting and leaching parameters, so that the method has the advantages of low cost, high efficiency, low energy consumption and the like, and is suitable for large-scale industrial production. The method is low in energy consumption and environment-friendly, and is applied to resource recycling of the retired ternary lithium battery, and the precursor can be used for reproducing a positive electrode material or used for a catalytic material.

The invention relates to a solid-phase preparation method and application of battery-grade lithium sulfide, and the preparation method comprises the following steps: (1) firstly, adopting industrial-grade lithium carbonate as a raw material, and carrying out pretreatment purification to remove sodium-calcium-magnesium metal ion impurities; (2) carrying out ball-milling mixing on the purified lithium carbonate raw material and sulfur powder, and carrying out low-temperature melting pre-sintering; (3) performing primary high-temperature calcination on the lithium carbonate and sulfur powder mixture under a protective atmosphere to synthesize a lithium sulfide crude product; (4) carrying out secondary high-temperature calcination on the lithium sulfide crude product in a protective atmosphere to remove excessive sulfur impurities and lithium polysulfide impurities so as to obtain purified lithium sulfide; and (5) carrying out ball milling and crushing on the obtained lithium sulfide, and screening to obtain the battery-grade lithium sulfide with different particle sizes. According to the preparation method, a high-temperature solid-phase synthesis method is adopted, and low-temperature melting pre-sintering and high-temperature two-step calcining methods are adopted, so that reaction byproducts are gas and are easy to remove, production and preparation of high-purity battery-grade lithium sulfide can be realized, and the product has excellent electrochemical performance.

The invention discloses fluoride-salt-free and nitrate-free high-temperature acid-resistant translucent glaze for steel plate enamel as well as a preparation method and application of the translucent glaze, and belongs to the technical field of enamel. The semitransparent glaze is prepared from quartz, anhydrous borax, titanium dioxide, trisodium phosphate, potassium carbonate, lithium carbonate, aluminum oxide, zinc oxide and sodium carbonate according to a specific mass ratio. The preparation method comprises the steps of raw material mixing, high-temperature melting under a pure oxygen condition, wiredrawing detection, quenching and the like. The semitransparent glaze is completely free of fluoride salt and nitrate, the problems of fluoride emission and environmental protection equipment blockage are avoided from the source, the fluorine content of the product is not detected through detection, the product meets the requirements of European Union REACH regulations, meanwhile, the product has good porcelain surface, luster and firing adaptability, is suitable for a steel plate matrix, has the firing temperature of 840-880 DEG C and the firing time of 820-830 minutes, and is suitable for a steel plate. The method can be used for producing green and environment-friendly enamel products.

The invention discloses fluoride salt-free and nitrate-free low-temperature matte glaze for steel plate enamel as well as a preparation method and application of the low-temperature matte glaze, and belongs to the technical field of enamel. The matte glaze is prepared from quartz, borax pentahydrate, sodium carbonate, titanium dioxide, magnesium oxide, monopotassium phosphate, calcium carbonate, zinc oxide, magnesium carbonate, lithium carbonate, aluminum oxide and zirconium silicate according to a specific mass ratio. The preparation method comprises the following steps: mixing the raw materials, melting at 1300 + / -10 DEG C in a pure oxygen environment, and quenching after wiredrawing to detect a molten state. The matte glaze completely avoids the use of fluoride salt and nitrate, the problems of fluoride emission and environmental protection equipment blockage are eliminated from the source, the fluorine content of the product is not detected through detection, and the limit value requirements of European Union REACH regulations are met. Zinc oxide and ZnO / TiO2 are added, so that the liquid phase viscosity is reduced, ion diffusion is accelerated, and the opacity (opacification performance) and gloss of the porcelain glaze are enhanced.

The invention discloses a fluoride-salt-free and nitrate-free cast iron enamel zirconium white glaze as well as a preparation method and application thereof, and belongs to the technical field of enamel. The zirconium white glaze is prepared from quartz, borax pentahydrate, magnesium carbonate, potassium carbonate, potassium feldspar, zinc oxide, aluminum hydroxide, calcium carbonate, zirconium silicate, sodium tripolyphosphate and lithium carbonate according to a specific mass ratio. The preparation method comprises the steps of raw material mixing, high-temperature melting under a pure oxygen condition, wiredrawing detection, quenching and the like. The zirconium white glaze is completely free of fluoride salt and nitrate, the problems of fluoride emission and environmental protection equipment blockage are avoided from the source, the fluorine content of the product is not detected through detection, the product meets the requirements of European Union REACH regulations, and meanwhile, the zirconium white glaze has good porcelain surface, luster and firing adaptability, is suitable for cast iron matrixes, has the firing temperature of 740-760 DEG C and the firing time of 87-87 hours, and can be widely applied to cast iron substrates. The method can be used for producing green and environment-friendly enamel products.

The invention relates to lithium sulfide and a preparation method thereof.The preparation method includes the following steps that sublimed sulfur powder and a lithium source are mixed and subjected to a heating reaction, and the lithium source comprises at least one of anhydrous lithium hydroxide, lithium hydroxide monohydrate, lithium oxide, lithium hydride and lithium carbonate; a reducing gas is introduced while the heating reaction is performed, or the reducing gas is introduced after the heating reaction is finished, and a reduction reaction is performed; and after the reaction is finished, introducing protective gas for calcining to prepare the lithium sulfide. The preparation method provided by the invention can realize low-cost and high-purity production of lithium sulfide, and ensures the safety and environmental protection of the production process.

The invention discloses fluoride-salt-free and nitrate-free low-temperature pearlescent glaze for steel plate enamel as well as a preparation method and application of the pearlescent glaze, and belongs to the technical field of enamel. The pearlescent glaze is prepared from quartz, anhydrous borax, titanium dioxide, magnesium carbonate, sodium tripolyphosphate, potassium carbonate, lithium carbonate, potassium feldspar, zinc oxide and V-26 according to a specific mass ratio. The preparation method comprises the steps of raw material mixing, high-temperature melting under a pure oxygen condition, wiredrawing detection, quenching and the like. The pearlescent glaze is completely free of fluoride salt and nitrate, the problems of fluoride emission and environmental protection equipment blockage are avoided from the source, the fluorine content of the product is not detected through detection, the product meets the requirements of European Union REACH regulations, meanwhile, the pearlescent glaze has good porcelain surface, luster and low-temperature firing adaptability, is suitable for a steel plate matrix, has the firing temperature of 760-800 DEG C and the firing time of 10-20 minutes, and is suitable for a steel plate. The method can be used for producing green and environment-friendly enamel products.

The invention discloses fluoride-salt-free and nitrate-free low-temperature acid-resistant translucent glaze for steel plate enamel as well as a preparation method and application of the translucent glaze, and belongs to the technical field of enamel. The semitransparent glaze is prepared from quartz, anhydrous borax, titanium dioxide, trisodium phosphate, potassium carbonate, lithium carbonate, aluminum oxide, zinc oxide and sodium carbonate according to a specific mass ratio. The preparation method comprises the steps of raw material mixing, high-temperature melting under a pure oxygen condition, wiredrawing detection, quenching and the like. The semitransparent glaze is completely free of fluoride salt and nitrate, the problems of fluoride emission and environmental protection equipment blockage are avoided from the source, the fluorine content of the product is not detected through detection, the product meets the requirements of European Union REACH regulations, meanwhile, the product has good porcelain surface, luster and low-temperature firing adaptability, and is suitable for steel plate substrates, the firing temperature is 760-800 DEG C, and the firing time is 2-3 hours. The method can be used for producing green and environment-friendly enamel products.

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 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 field of lithium manganate positive electrode materials, in particular to a lithium manganate positive electrode material and a preparation method thereof, a positive electrode plate and a battery, which are used for solving the problems of Jahn-Teller distortion of Mn < 3 + >, Mn dissolution and low conductivity in circulation. Lithium carbonate, manganous-manganic oxide, potassium carbonate, aluminum nitrate and absolute ethyl alcohol are subjected to ball milling and then sintered to obtain K / Al co-doped lithium manganate powder, then the K / Al co-doped lithium manganate powder is coated with an acetylferrocene / diphenylamine polymer, finally, the K / Al co-doped lithium manganate powder is coated with an AlF3 (at) CeF3 suspension, and finally the lithium manganate positive electrode material is obtained. According to the lithium manganate positive electrode material, the electronic conductivity is greatly improved, the rate capability is improved, and the cycling stability is improved; and the material has excellent cycling stability and rate capability.

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 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 recovering lithium and fluorine from aluminum electrolysis hazardous waste, which comprises the following steps: firstly, mixing organic polyol and alkaline hydroxide according to a molar ratio of 1: (0.5-2) to obtain a eutectic solvent; heating the eutectic solvent to 80-150 DEG C, and adding a proper amount of raw material fine powder and calcium oxide for reaction leaching; carbonating and filtering the leachate to obtain lithium carbonate; washing the leaching residues with an acetic acid solution to obtain a calcium fluoride product; the concentration of fluorine ions in the leachate is smaller than or equal to 200 ppm, and the purity of calcium fluoride is larger than or equal to 90%; the leaching rate of lithium in the method is greater than 85%; the slag feeding rate of fluorine is greater than 95%; and no hydrogen fluoride gas is generated in the method. According to the method, a non-toxic and biodegradable eutectic solvent is adopted as a leaching agent, and efficient leaching of lithium and fluorine in the aluminum electrolysis dangerous waste materials is achieved; calcium oxide is used as a precipitating agent, free fluorine is promoted to be precipitated and recycled as calcium fluoride, the whole process meets the requirement of green metallurgy, and the win-win situation of resources and the environment is achieved.

The invention relates to the technical field of battery material recovery, and particularly discloses a method for efficiently recovering lithium and ferrous sulfate heptahydrate in retired lithium iron phosphate through total leaching and green impurity removal. Comprising the following steps: 1, adding strong base and a carbon source into black powder, and calcining at high temperature in an inert atmosphere; step 2, dissolving in pure water after calcining, and carrying out suction filtration to obtain a lithium salt solution and ferrous hydroxide; 3, sulfuric acid is added into ferrous hydroxide for suction filtration, and graphite and a ferric salt solution are obtained; drying the ferric salt solution to obtain ferrous sulfate heptahydrate; step 4, adding alkali into the lithium salt solution to obtain a purified lithium salt solution; 5, introducing carbon dioxide into the purified lithium salt solution, and adding alkali to generate lithium carbonate precipitate; and 6, finally carrying out heat preservation, suction filtration, washing and drying to obtain a lithium carbonate finished product. The technical problems that in the prior art, a traditional decommissioned lithium iron phosphate battery grading recycling technology is complex in production process, more waste liquid pollution is generated, and the production cost is relatively high are solved.

The invention provides a comprehensive utilization method of clay type lithium ore, and relates to the field of hydrometallurgy. The comprehensive utilization method of the clay type lithium ore comprises the following steps: mixing the clay type lithium ore with concentrated sulfuric acid, and carrying out low-temperature roasting at the temperature of 100-300 DEG C to obtain a roasted cured material; adding water into the roasted and cured material, leaching, and carrying out solid-liquid separation to obtain a lithium-rich aluminum leaching solution; adsorbing the lithium-rich aluminum leaching solution by using an aluminum ion sieve adsorbent to obtain an aluminum-rich adsorbed solution and a lithium-loaded ion sieve; analyzing the lithium-loaded ion sieve to obtain a lithium-rich desorption solution; the lithium-rich desorption solution is sequentially subjected to purification and lithium precipitation, and battery-grade lithium carbonate is obtained; sequentially carrying out iron removal, purification and impurity removal on the aluminum-rich adsorption post-liquid to obtain iron slag and an aluminum sulfate solution; and sequentially carrying out aluminum precipitation and roasting on the aluminum sulfate solution to obtain the metallurgical-grade aluminum oxide. The method has the advantages of high-efficiency leaching of lithium and aluminum, high-efficiency separation of lithium and aluminum, environment friendliness, simple process and the like.

The method comprises the following steps: uniformly mixing iron phosphate, lithium carbonate, a carbon source and an additive, carrying out grinding and spray-drying to obtain a spray-dried material, carrying out primary sintering on the spray-dried material to obtain a primary sintered product, uniformly mixing the primary sintered material with a lithium source, the carbon source and the additive, transferring the mixture into a furnace, and carrying out secondary sintering to obtain the high-performance lithium iron phosphate cathode material. And carrying out secondary burning in a protective atmosphere, discharging from the furnace after the secondary burning is finished, and carrying out air jet pulverization to obtain a finished product of secondary burning lithium iron phosphate. The ultra-high-pressure solid lithium iron phosphate positive electrode material is prepared by a two-mixing two-firing method, and lithium and carbon are supplemented by a lithium element, a carbon source and an additive; the preparation method has the advantages that the particle size can be inhibited, the effects of repairing a carbon layer, improving the particle morphology, increasing the Li < + > diffusion coefficient and the like are achieved by combining secondary sintering, and indexes such as capacity increasing, voltage efficiency improving, resistivity reducing, iron dissolution and the like can be achieved while the material compaction is improved.

The invention discloses lithium sulfide, a two-step double decomposition preparation method and application of the lithium sulfide in an all-solid-state battery, and belongs to the technical field of solid-state batteries. According to the preparation method, a two-step decomposition synthesis technology is adopted, lithium carbonate and ammonium thiocyanate are used as raw materials, the raw materials are uniformly mixed and then placed in a high-temperature reactor, a step heating sintering procedure is completed in an inert gas atmosphere, and the purpose of fully decomposing and converting the raw materials is achieved by accurately controlling the temperature and the time; after a product is obtained through reaction, the high-purity lithium sulfide material is obtained after the product is cooled to the room temperature. The method for preparing the lithium sulfide is low in raw material cost, simple in reactant formula and free of side reaction in the reaction process, and the finally generated product is few in impurity, high in purity and good in crystallinity.

The invention provides a positive electrode active material and a preparation method thereof, a positive plate and a battery. An inner slow-release layer in the positive electrode active material coats at least part of the surface of a positive electrode active material main body, and an outer inhibition layer coats at least part of the surface of the inner slow-release layer; the inner slow-release layer comprises lithium carbonate and M metal oxide, and the outer inhibition layer comprises at least one of nitride, fluoride and oxide of inhibition elements; the inhibiting elements comprise at least two elements in VA, IVA family, IIIA family, IIA family and IVB family. The lithium carbonate in the inner slow-release layer can release non-flammable gas mainly containing CO2, the metal oxide can inhibit release of lattice oxygen in the positive electrode active material main body at high temperature, and the proportion of combustible gas is reduced. The lithium carbonate is provided with a temperature decomposition window, so that the release time of carbon dioxide pressure relief for the first time can be accurately controlled. And the outer inhibition layer can avoid the contact between the positive electrode active material main body and the electrolyte, so that the proportion of the combustible gas is further reduced.

Low CAPEX / OPEX, effective, and environmentally friendly process of rapidly extracting lithium from geothermal brines and producing lithium carbonate. The method includes adjusting a unique parameter determined based on the modified alkalinity in a quantity of the geothermal brine to a preset value without needing to purposefully modify the pH. Interactions of the anionic reactant species with components within the geothermal brine cause a solid form of the lithium to precipitate out of the geothermal brine. After the solid separation, the spent brine is environmentally safe and returned underground or transported to a reservoir.

The present application relates to a kind of methods for recycling iron phosphate and lithium carbonate from waste, including iron phosphate, lithium carbonate and glucose in the waste, the method comprises the following steps: (1) waste is pickled to obtain iron phosphate crude material and lithium-containing solution;(2) lithium-containing solution obtained in step (1) is sequentially subjected to oxidative decomposition, neutralization precipitation, solid-liquid separation, enrichment concentration, impurity removal, lithium precipitation and post-treatment process, to obtain the lithium carbonate;(3) the iron phosphate crude material obtained in step (1) is washed with water to obtain the iron phosphate;Step (2) and step (3) are not in order of precedence.The method provided by the present application can effectively remove glucose and other impurities in the waste, achieve decolorization, and the obtained lithium carbonate can reach battery grade, realizing the recycling of iron phosphate and lithium carbonate in waste, improving the utilization value and economic benefits of waste in the production of lithium iron phosphate.

The invention provides a method for preparing aluminum oxide and extracting lithium from lithium-rich bauxite waste rocks, and belongs to the technical field of solid waste comprehensive utilization. The method comprises the following steps: crushing and grinding the lithium-rich bauxite waste rocks, mixing with an acid mixed solution, leaching to remove iron to obtain a low-iron filter cake, adding concentrated sulfuric acid, roasting, curing, leaching with water, carrying out hot filtration to obtain a filtrate, adding a crystallizing agent, dissolving, evaporating to obtain a steel belt crystallizer crystal, stirring and washing a saturated solution to obtain a lithium-containing solution and low-iron aluminum ammonium sulfate, purifying the lithium-containing solution to remove impurities, and precipitating lithium with sodium carbonate to prepare lithium carbonate; and calcining the low-iron ammonium aluminum sulfate to prepare aluminum oxide. The method provided by the invention has the advantages of simple process, low energy consumption in roasting and leaching of aluminum and lithium, high recovery rate of valuable components of aluminum and lithium, high iron removal rate, high separation efficiency of aluminum and lithium, low extraction cost of aluminum and lithium, recyclability of the crystallizing agent and the like, is easy for industrial implementation, and greatly improves the comprehensive utilization value of the lithium-rich bauxite waste rocks.

The invention relates to the technical field of building glazed tiles, in particular to an antibacterial glazed tile and a preparation method thereof.The antibacterial glazed tile comprises a green body layer and an antibacterial glaze layer which are sequentially arranged from bottom to top; wherein the antibacterial glaze layer is obtained by calcining antibacterial glaze; the antibacterial glaze is prepared from the following raw materials: high-temperature antibacterial frit, calcined kaolin, corundum, quartz, dolomite, calcined talc, strontium carbonate, wollastonite, potassium feldspar and albite; the high-temperature antibacterial frit is prepared from the following raw materials: zirconium silicate, a silver antibacterial agent, calcined aluminum oxide, calcined talc, quartz, wollastonite, kaolin, calcium phosphate, potassium feldspar, albite, boric acid and lithium carbonate. According to the antibacterial glazed tile and the preparation method thereof provided by the invention, the formula of the antibacterial glaze is optimized, so that the antistatic property and the corrosion resistance can be improved on the premise of ensuring the antibacterial property of the antibacterial glazed tile.

The invention discloses a synthesis method of lithium phosphorus sulfur chloride, and relates to the technical field of preparation of sulfide solid electrolyte for all-solid-state lithium ion batteries, and the scheme is as follows: the synthesis method of lithium phosphorus sulfur chloride comprises the following steps: pretreatment of raw materials: mixing lithium carbonate (Li2CO3), phosphorus pentasulfide (P2S5), lithium chloride (LiCl) and elemental sulfur (S) according to a preset ratio, and then adding a catalyst, grinding and dispersing for a preset time to obtain uniformly dispersed mixed powder; reduction reaction: fully mixing the mixed powder with a reducing agent, heating to a first preset temperature condition, and carrying out reduction reaction to obtain a reduction product; sintering and purifying: heating the reduction product to a second preset temperature, and sintering to form a lithium phosphorus sulfur chloride (Li6PS5Cl) crystal phase to obtain a lithium phosphorus sulfur chloride (Li6PS5Cl) product; the raw material cost can be remarkably reduced, the process safety and economy are optimized, and large-scale industrial preparation of lithium phosphorus sulfur chlorine is realized.

The application relates to a quality inspection technology of inorganic salt, and discloses a detection reagent and a rapid detection method for high-purity lithium carbonate. A water-soluble fluorescent probe detection reagent is obtained by using 2-(4-chlorophenyl) benzoxazole, 2-(2-hydroxyphenyl) benzoxazole and other benzoxazole compounds as a substrate, and by modifying the substrate with glycerol, tris(hydroxyl) aminomethane and other compounds; high-purity lithium carbonate is detected by using the detection reagent; the high-purity lithium carbonate is solid-phase prepared into lithium carbonate suspension liquid; the upper liquid phase of the lithium carbonate suspension liquid is taken; the fluorescent probe detection reagent is added into the upper liquid phase; and the high-purity lithium carbonate is rapidly detected according to the fluorescent spectrum and a working curve. The application can realize the rapid detection of the high-purity lithium carbonate in a water-soluble environment, and the detection response time can be as short as 3-10 seconds.

The invention discloses a method for preparing high-purity lithium sulfide based on a solution double decomposition method, and belongs to the technical field of battery materials, and the method comprises the following steps: adding lithium chloride and sodium sulfide into ethanol, mixing, and reacting in the mixing process to generate lithium sulfide; performing solid-liquid separation on the reaction system to obtain a solid product; washing the solid product with tetrahydrofuran and drying; and continuously introducing inert gas into the heat treatment chamber to purge a solid product in the heat treatment chamber, carrying out heat treatment on the solid product under the conditions of 200-300 DEG C and 10-1000 Pa, and removing complex impurities in the solid product to obtain the high-purity lithium sulfide. Compared with the prior art, the method has the advantages that the Li2S.EtOH impurity in the lithium sulfide is removed, the lithium carbonate impurity generated by the reaction of the impurity at high temperature is reduced, and the risk of electrolyte and battery performance is further reduced.

The invention relates to a method for comprehensively recycling a positive electrode material of a waste lithium iron phosphate battery, which comprises the following steps of: (1) discharging the waste lithium iron phosphate battery: providing a power supply by the waste lithium iron phosphate battery, and electrolyzing a lithium precipitation mother solution by using a three-chamber diaphragm electrolytic bath; (2) crushing and sorting; (3) two-stage leaching: leaching the lithium iron phosphate positive electrode powder with a sulfuric acid solution generated by electrolysis of a lithium precipitation mother solution, and adding an aeration disc at the bottom of a reaction kettle for aeration; adding a dilute sulfuric acid solution generated by electrolysis of lithium precipitation mother liquor into first-section leaching residues for leaching; (4) two-stage impurity removal; and (5) preparing lithium carbonate. According to the method, the lithium precipitation mother liquor for the waste lithium iron phosphate battery is discharged to prepare the sulfuric acid and sodium hydroxide-lithium hydroxide mixed solution for production, so that residual electricity is utilized, a production reagent is saved, and the problems of high energy consumption, large lithium loss and poor sale of a byproduct sodium sulfate in evaporative crystallization of sodium sulfate are solved; and the aim of circularly and comprehensively utilizing the waste lithium iron phosphate battery is fulfilled.

The invention discloses a preparation method and application of lithium iron phosphate, and belongs to the field of lithium ion battery positive electrode materials. The preparation method comprises the following steps: (1) pre-sintering a lithium iron phosphate precursor; (2) uniformly mixing the pre-sintered lithium iron phosphate precursor with a lithium source, a phosphorus source, a doping element and a carbon source, grinding, and carrying out spray drying to obtain a spray material; and (3) carrying out sintering treatment on the spray material, and carrying out crushing and demagnetizing treatment after cooling to obtain the lithium iron phosphate. The pre-sintering temperature in the step (1) is 500-750 DEG C, and the pre-sintering time is 4-8 hours. The lithium source in the step (2) is one or more of lithium carbonate, lithium hydroxide, lithium dihydrogen phosphate and lithium phosphate; the phosphorus source is one or more of phosphoric acid, lithium dihydrogen phosphate and iron phosphate; the carbon source is at least two of glucose, cane sugar, polyethylene glycol and starch. The lithium iron phosphate provided by the invention can achieve the effects of low specific surface area, high compaction density and excellent electrochemical performance.

A more efficient and lower waste liquid-phase method for recovering lithium carbonate suitable for high-performance lithium applications from recycled lithium-ion battery and other sources of lithium hydroxide including aqueous solutions is described. The method uses carbon dioxide gas to directly form lithium carbonate from a lithium hydroxide including solution, thus eliminating the need for conventional acid pre-treatment and reducing the need for subsequent sodium carbonate addition.