67 results about "Lithium bicarbonate" patented technology

The invention discloses a preparation method of lithium trifluoromethanesulfinate, and belongs to the field of lithium ion battery materials. The preparation method of the lithium trifluoromethanesulfinate comprises the following steps: 1, mixing trifluoromethanesulfonyl chloride, lithium sulfite, lithium bicarbonate and a first solvent, and heating to react; 2, dissolving the concentrated crude product in a second solvent, and filtering and separating a lithium sulfate solid; and 3, concentrating the filtrate, adding a third solvent, uniformly stirring, filtering and separating the lithium chloride solid, and concentrating to obtain the lithium trifluoromethanesulfinate. According to the method for preparing the lithium trifluoromethanesulfinate, the yield can reach 94%, the operation is simple, byproducts are easy to separate, and the method is suitable for industrial production. In addition, the obtained by-product lithium sulfate can be used for preparing lithium sulfide, the by-product lithium chloride can be used for preparing solid electrolyte, and resource utilization is achieved.

The invention discloses a filtering device for lithium liquid extraction, and relates to the technical field of lithium liquid extraction. Comprising a tank body and a tank cover movably connected to the top of the tank body, the top of the tank cover and the left side of the tank body are fixedly connected with a discharging pipe and a feeding pipe respectively, a filter drum is arranged in the tank body, and the anti-blocking assembly is arranged in the tank body and used for reducing the blocking probability of the filter drum; the anti-blocking assembly comprises a flow guide baffle arranged on the inner wall of the left side of the tank body and corresponding to the feeding pipe, a spring is fixedly connected between the flow guide baffle and the side wall of the tank body, the right side of the flow guide baffle is fixedly connected with a cleaning arm, and the right side of the cleaning arm is fixedly connected with a cleaning brush; a connecting seat is arranged at the top of the filter cartridge; by avoiding direct impact on a specific area and continuous cleaning treatment, the smoothness of the filter cartridge is greatly guaranteed, meanwhile, lithium bicarbonate mother liquor entering the tank body also penetrates through the filter cartridge from different directions, the capturing and intercepting area of the filter cartridge is increased, and the capturing effect of the resin trapper is optimized.

This invention provides a continuous production apparatus for preparing lithium bicarbonate using CO2, relating to the field of lithium carbonate preparation technology. It includes a feeding system, a mixing reaction unit, a clarification and separation unit, a frame, and a control system. The feeding system's organic phase feeding unit, aqueous phase feeding unit, and gas inlet unit enable precise proportioning and conveying of multiple materials. The preparation container of the mixing reaction unit is divided into multiple stirring chambers by annular baffles, each corresponding to a set of impellers. Optimized impeller parameters and axial spacing design, coupled with a microporous aeration device at the bottom of the preparation container, form a highly efficient composite flow field, enhancing three-phase mixing efficiency. The clarification and separation tank improves the gradient separation of the gas, liquid, and liquid phases through filter baffles. Through the coordinated operation of these systems, mixing reaction and product separation can be efficiently completed, achieving continuous production of lithium bicarbonate solution, ensuring product uniformity, and significantly improving CO2 utilization and gas-liquid mass transfer efficiency, which is of great significance for the industry's green and low-carbon transformation.

The application discloses a method for recycling battery-grade iron phosphate and lithium carbonate by using waste lithium iron phosphate battery materials. The method comprises the following steps: ①electrified crushing and disassembling the waste lithium iron phosphate battery materials, slurry, concentrated sulfuric acid leaching, pressure filtration, and obtaining an acid leaching solution; ②removing copper, aluminum and fluorine in the acid leaching solution in sequence; ③adjusting the iron-phosphorus ratio and pH value of the solution to precipitate iron phosphate, then aging the iron phosphate, two-stage pressure filtration and washing, drying and roasting to obtain battery-grade iron phosphate; ④removing iron from the solution after precipitating iron phosphate, pressure filtration, evaporation crystallization, adding sodium carbonate to precipitate lithium, and obtaining crude lithium carbonate, which is washed, slurried, carbonized, pressure filtered to prepare lithium bicarbonate filtrate, and then the lithium bicarbonate filtrate is refined, the resin is used to remove calcium and magnesium, thermal decomposition, centrifugal washing separation and drying to obtain battery-grade lithium carbonate. The application has high recovery rate of valuable elements, good impurity removal effect, can obtain battery-grade iron phosphate and lithium carbonate, and has high-efficiency and environmental protection process design, and is suitable for industrial application.

The preparation method comprises the following steps: mixing a lithium source material, water, a first solvent and quaternary amine alkali, reacting the quaternary amine alkali with carbon dioxide in a reaction atmosphere containing carbon dioxide to generate HCO3 <->, reacting the HCO3 <-> with lithium ions in the lithium source material to generate lithium bicarbonate, and collecting a water phase after the reaction; decomposing lithium bicarbonate in the water phase to generate lithium carbonate, collecting a solid phase, and decomposing lithium carbonate in the solid phase to generate lithium oxide to obtain an intermediate; dissolving quaternary ammonium iodide in a second solvent, adding the intermediate, converting the lithium oxide into lithium hydroxide, carrying out ion exchange on the lithium hydroxide and the quaternary ammonium iodide to generate lithium iodide, and collecting a liquid phase; and collecting the lithium iodide in the liquid phase. According to the present invention, based on the characteristics of the specific quaternary ammonium base and the quaternary ammonium iodide salt, the Li in the lithium source material is selectively reinforced, carbonized and leached, the anion impurities in the lithium source material are removed, the anion exchange in the organic phase is achieved, and the high-purity anhydrous lithium iodide is prepared.

The present application relates to the field of battery raw material preparation, and discloses a lithium bicarbonate pyrolysis device for preparing lithium carbonate, comprising a reactor body, a stirring mechanism, a clamping mechanism, and a toggle mechanism. After the lithium bicarbonate solution is injected into the main reactor body, the stirring paddle stirs the solution at the bottom of the main reactor body. At the same time, since the plug in the clamping mechanism is inserted into the thread groove of the threaded rod, the clamping mechanism is driven to move upward by the threaded rod. At this time, the toggle mechanism moves upward together with the clamping mechanism. As the toggle mechanism moves upward, under the relative resistance of the solution, the hinge plate rotates downward, so that the heated solution located above the toggle mechanism and near the inner wall of the main reactor body flows toward the threaded rod below the toggle mechanism, thereby making the temperature of the solution in the main reactor body uniform, avoiding the gradient distribution of the solution with high edge temperature and low center temperature due to low heat exchange efficiency, which in turn causes the wall sticking phenomenon.

The invention relates to the technical field of lithium carbonate preparation, and provides a method for extracting battery-grade lithium carbonate from lithium precipitation mother liquor. The method comprises the following steps: adding lime milk into the lithium precipitation mother liquor to adjust the pH value, and then filtering to obtain a calcium and magnesium removal raw material; treating the calcium and magnesium removal raw material with calcium removal resin to obtain a refined raw material; performing three-stage extraction on the refined raw material and a lithium extraction extractant to obtain a lithium-loaded extractant; carrying out three-stage washing on the lithium-loaded extraction agent and pure water to obtain a clean lithium-loaded extraction agent; reacting the clean lithium-loaded extracting agent with pure water and carbon dioxide in a reverse extraction tower to obtain a lithium bicarbonate solution; treating the lithium bicarbonate solution through an oil removal resin column and a calcium and magnesium removal resin column in sequence to obtain a clean lithium bicarbonate solution; and pyrolyzing the lithium bicarbonate solution, and centrifugally separating to obtain a battery-grade lithium carbonate product. According to the method, efficient enrichment and purification of lithium are realized through multi-stage separation and conversion, and the strict requirement of battery-grade lithium carbonate on purity is finally met.

The invention discloses a method for preparing a silicon alloy and lithium carbonate by taking lithium ore as a raw material and application of the silicon alloy and the lithium carbonate. The method comprises the following steps: S1, carrying out high-temperature carbon thermal reduction smelting treatment on a mixed raw material, and cooling to obtain a silicon alloy and a lithium-rich product; s2, carrying out mixed acid roasting, leaching, impurity removal and lithium precipitation treatment on the lithium-rich product by using sulfuric acid, and carrying out centrifugal separation to obtain crude lithium carbonate; s3, the crude lithium carbonate is placed in deionized water, CO2 gas is introduced for a carbonization reaction, a lithium bicarbonate solution is obtained, then the lithium bicarbonate solution is subjected to thermal decomposition treatment, and final lithium carbonate is obtained. According to the method, the iron oxide with low cost is adopted as the raw material, the silicon alloy and the lithium-rich product are prepared through high-temperature reduction of the lithium ore, then the lithium element is extracted from the lithium-rich product through the wet process technology, and multi-component comprehensive utilization of lithium, silicon and aluminum resources in the lithium ore is achieved.

The invention provides a device system and method for preparing high-purity lithium carbonate through micron / nano bubble deep carbonization-pyrolysis. The device system comprises a slurrying device, a first-stage deep carbonization device, a second-stage deep carbonization device, a pyrolysis device, a nano bubble generator, a first-stage micro bubble generator and a second-stage micro bubble generator. The slurrying device, the first-stage deep carbonization device, the second-stage deep carbonization device and the pyrolysis device are sequentially connected along the material flow direction; the first-stage deep carbonization device is bidirectionally connected with the first-stage microbubble generator; the secondary deep carbonization device is bidirectionally connected with the nano bubble generator; and the pyrolysis device is bidirectionally connected with the secondary microbubble generator. A micro-bubble generator or a nano-bubble generator is introduced into the first-stage deep carbonization device, the second-stage deep carbonization device and the pyrolysis device, so that the CO2 mass transfer rate is increased, the deep carbonization of lithium carbonate and the pyrolysis process of lithium bicarbonate are enhanced, and a uniform and fine high-purity lithium carbonate product can be efficiently prepared.

Provided is a method for producing a lithium carbonate from a basic lithium- and aluminum-containing waste liquid generated during a positive electrode material production process, the method comprising the steps of: (a) filtering the waste liquid to remove metal solids; (b) injecting carbon dioxide into the waste liquid removed of the metal solids, thereby converting a lithium hydroxide into a lithium bicarbonate; (c) adding an anion exchange resin to the lithium bicarbonate-containing waste liquid to convert a lithium sulfate into a lithium hydroxide; (d) injecting carbon dioxide into the lithium hydroxide-containing waste liquid to convert the lithium hydroxide into a lithium carbonate; and (e) concentrating the lithium carbonate-containing waste liquid using an evaporator and then recovering a solid lithium carbonate.

The present application relates to the technical field of separation and purification of inorganic materials, and specifically discloses a method for preparing lithium carbonate from lithium ore. The preparation method comprises: pre-treating the lithium ore, adding water, stirring and leaching, and filtering to obtain a leachate; adding a complexing agent to the leachate, mixing, filtering, collecting a filter cake, adding deionized water and a complexing agent to the filter cake, and simultaneously introducing carbon dioxide to obtain a solution containing lithium bicarbonate; mixing with a cationic chelating resin, reacting, filtering, and collecting a filtrate to obtain a first mixed solution; mixing the first mixed solution with an anion exchange resin, reacting, filtering, and collecting a filtrate to obtain a second mixed solution; adding sodium carbonate to the second mixed solution, mixing, filtering, and obtaining a crude lithium carbonate product; repeatedly washing with water, filtering, and drying to obtain lithium carbonate. The method for preparing lithium carbonate from lithium ore of the present application has the advantages of reducing impurities and improving the purity of lithium carbonate through the synergistic effect between the steps.

The invention provides a method for preparing lithium carbonate by using lithium iron phosphate waste batteries, which comprises the following steps: adding inorganic acid and hydrogen peroxide into dispersion liquid containing lithium iron phosphate battery powder, reacting the dispersion liquid under the conditions that the pH value is 2.1-2.5 and heating is performed, and performing suction filtration and washing to obtain first filtrate; adding a composite impurity removal agent containing sodium hydroxide and calcium hydroxide into the first filtrate under the hot bath condition, reacting the first filtrate under the condition that the pH value is 10-10.5, and performing suction filtration and washing to obtain second filtrate; performing extraction and carbon dioxide back extraction on the second filtrate to obtain back extraction liquid containing lithium bicarbonate; and pyrolyzing lithium bicarbonate in the back extraction liquid to obtain lithium carbonate.

According to the invention there is provided a process comprising admixing lithium iron phosphate (LFP), an oxidizing agent, carbon dioxide, and water; separating an aqueous solution that includes lithium carbonate and / or lithium bicarbonate from the admixture.

This invention discloses a method for the green recycling of all components of waste lithium iron phosphate batteries, belonging to the field of new energy resource recycling technology. The invention involves crushing and slicing the waste batteries in an aqueous solution continuously purged with carbon dioxide, prioritizing the non-destructive separation of the negative electrode graphite; the metal sheets are sorted to obtain the iron shell, separator, copper foil, and aluminum foil containing powder; a gas-liquid-solid Fenton reaction system is constructed using carbon dioxide, hydrogen peroxide, and lithium iron phosphate, simultaneously degrading PVDF and electrolyte, and performing dealuminization and lithium impregnation under mild, acid- and alkali-free conditions; the slurry is subjected to two-stage sieving to obtain delithiated iron phosphate powder, and lithium bicarbonate solution is heated and decomposed to obtain lithium carbonate, achieving a closed-loop carbon dioxide recycling process. This invention solves the problems of high energy consumption from high-temperature roasting, significant pollution from strong acids and alkalis, difficulty in separating mixed components, and damage to graphite and metal foil in traditional recycling methods. It achieves high-purity recycling of all components—negative electrode graphite, copper foil, aluminum foil, iron phosphate, and lithium—with low energy consumption and no high-salt wastewater, making it suitable for large-scale application.

A process for purifying crude lithium carbonate includes carbonation of a slurry of the crude lithium carbonate feed in water with exhaust flue gas to form an aqueous solution of lithium bicarbonate, followed by separation of the solution from insoluble impurities, and depressurization and heating of the separated solution to precipitate solid lithium carbonate and evolve carbon dioxide. The process produces battery-grade purified lithium carbonate and purified carbon dioxide which can be captured for further use, while reducing carbon dioxide emissions from exhausted flue gas and avoiding the need to use pre-purified carbon dioxide as a reactant.

This invention relates to a method for removing lithium carbonate scale from the surface of equipment such as crystallization apparatus and evaporation apparatus. A non-acidic cleaning solution, such as water, is introduced into the apparatus. Once inside the apparatus, CO2 is injected and mixed with the cleaning solution. This converts the lithium carbonate scale into lithium bicarbonate, which dissolves in the cleaning solution. Subsequently, the cleaning solution containing the dissolved lithium bicarbonate is discharged from the apparatus.

The invention relates to a method for removing lithium carbonate scale from the surface of equipment such as crystallizers and evaporators. A non-acid cleaning solution, such as water, is introduced into the apparatus. Once into the apparatus, CO2 is injected into the apparatus and mixed with the cleaning solution. This results in the conversion of lithium carbonate scale into lithium bicarbonate dissolved in the cleaning solution. The cleaning solution containing the dissolved lithium bicarbonate is then discharged from the device.

A preparation method of lithium iodide and a solid-state battery, the preparation method comprising mixing a lithium source material, water, a first solvent and a quaternary amine base, reacting the quaternary amine base with carbon dioxide under a reaction atmosphere containing carbon dioxide to generate HCO3 ‑ , HCO3 ‑ reacting with lithium ions in the lithium source material to generate lithium bicarbonate, collecting an aqueous phase after the reaction; decomposing the lithium bicarbonate in the aqueous phase to generate lithium carbonate, collecting a solid phase, decomposing the lithium carbonate in the solid phase to generate lithium oxide to obtain an intermediate; dissolving a quaternary ammonium iodide salt in a second solvent and adding the intermediate, converting the lithium oxide into lithium hydroxide, and performing ion exchange between the lithium hydroxide and the quaternary ammonium iodide salt to generate lithium iodide, collecting a liquid phase; and collecting the lithium iodide in the liquid phase. Based on the characteristics of the specific quaternary amine base and the quaternary ammonium iodide salt, the application selectively enhances carbonization leaching of Li in the lithium source material, removes anion impurities in the lithium source material, and also realizes anion exchange in an organic phase and preparation of high-purity anhydrous lithium iodide.

A method for preparing lithium bis(fluorosulfonyl)imide, includes reacting bis(fluorosulfonyl)imide with lithium carbonate in a mixed organic solvent to obtain lithium bis(fluorosulfonyl)imide after post-treatment. In the synthetic route of the lithium bis(fluorosulfonyl)imide, the reaction process stays at the stage of lithium bicarbonate, so there is little water in the reaction system, and it is very easy to recover the generated lithium bicarbonate. The process is simple and can be used to prepare lithium bis(fluorosulfonyl)imide of high quality at a high yield.

The application provides a method for selectively separating lithium and impurities by multi-stage gradient carbon dioxide back extraction, comprising the following steps: subjecting a lithium-containing organic phase to N-stage carbon dioxide back extraction, wherein N>=2; in the N-stage carbon dioxide back extraction, the partial pressure of carbon dioxide is increased step by step; collecting lithium-containing back extraction liquid obtained by first-stage carbon dioxide back extraction; collecting impurity-containing back extraction liquid generated in stages other than the first-stage carbon dioxide back extraction, and subjecting the impurity-containing back extraction liquid to impurity removal treatment or recycling extraction and back extraction. The method for selectively separating lithium and impurities by multi-stage gradient carbon dioxide back extraction can directly obtain lithium bicarbonate solution with higher purity by designing gradient CO2 partial pressure in carbon dioxide back extraction, and most of the calcium, magnesium and other impurities are retained in subsequent stages, so that lithium bicarbonate solution with a purity of greater than or equal to 95% is obtained, and the amount of impurity removal agent can be greatly reduced when the impurity-containing back extraction liquid obtained subsequently is deeply removed.

According to the lithium-containing organic solution reverse extraction device provided by the invention, submicron carbon dioxide bubbles are generated through the aeration mechanism, so that the mass transfer efficiency of a gas-liquid-liquid three-phase reaction interface in the reverse extraction process is remarkably enhanced, and lithium ions are efficiently and quickly transferred from an organic phase to a water phase; the reaction rate and the carbon dioxide utilization rate in the reverse extraction process are greatly increased, the problems that in a traditional lithium extraction process, the mass transfer efficiency is low and continuous flow production cannot be achieved in the carbon dioxide reverse extraction working section are solved, the continuity and thoroughness of reverse extraction are further enhanced through the series connection design of the multiple stages of reverse extraction kettles and the arrangement of the transfer kettles, and the production efficiency is improved. The lithium in the organic phase is fully removed, the purity of the lithium bicarbonate solution and the blank organic solution is guaranteed, the subsequent process can be smoothly carried out, and the requirement of industrial production for continuous flow operation is met.

The invention belongs to the technical field of treatment of industrial wastewater containing inorganic salt, and discloses a method for recovering lithium carbonate from wastewater containing impurity lithium fluoride mother liquor, which comprises the following steps: firstly, determining an end point according to the moment when the conductivity value monitored on line is changed to the lowest point, so as to accurately control the addition of a carbonate precipitator; coprecipitating lithium ions and impurities to form a mixed solid phase; then introducing carbon dioxide into the slurry prepared from the solid phase again, determining a reaction endpoint according to the moment when the pH value change rate monitored on line reaches a peak value, and selectively converting lithium carbonate in the solid phase into soluble lithium bicarbonate to enter a liquid phase; according to the method, the operation process of first curing and temporary storage and then selective liquefaction is established, the two mutually restricted targets of wastewater purification and resource recovery are separated in the process time sequence, the process time sequence is optimized, the process time sequence is optimized, and the high-purity lithium carbonate is recovered by heating the solution rich in lithium bicarbonate. And the thoroughness of wastewater purification is no longer at the cost of sacrificing the feasibility of resource recovery.

The invention provides a waste lithium battery positive electrode material efficient leaching method based on electron beam rapid oxidation and application of the waste lithium battery positive electrode material efficient leaching method, and relates to the field of battery recycling. The leaching method comprises the following steps: S1, mixing black powder with water and carboxylate to prepare first slurry; and S2, carrying out electron beam irradiation treatment on the first slurry, introducing carbon dioxide, and carrying out solid-liquid separation to obtain a first lithium bicarbonate solution. Iron ions in lithium iron phosphate are rapidly oxidized by using an electron beam irradiation technology, and the use of hydrogen peroxide is reduced. Meanwhile, the effect of promoting lithium ion leaching can be achieved at normal temperature through electron beam irradiation, the requirement for the temperature in wet leaching is lowered, and therefore steam consumption is reduced.

The utility model discloses a kind of lithium bicarbonate continuous high-efficiency pyrolysis devices, comprising: main reactor, for lithium bicarbonate solution to carry out pyrolysis reaction;First heat exchanger, with main reactor communication, the gas after lithium bicarbonate solution pyrolysis in main reactor enters first heat exchanger;Transfer container, with main reactor communication, transfer container is used to collect pyrolysis mother liquor after lithium bicarbonate solution pyrolysis;Second heat exchanger, with transfer container connection, transfer container is used to supply pyrolysis mother liquor to second heat exchanger;Supply equipment, for supplying lithium bicarbonate solution to first heat exchanger, second heat exchanger;Three-way pipe, for communicating first heat exchanger, second heat exchanger and main reactor, first heat exchanger, second heat exchanger supply lithium bicarbonate solution in main reactor by three-way pipe.The lithium bicarbonate continuous high-efficiency pyrolysis device of the application utilizes the waste heat of pyrolysis device, effectively reduces resource waste.

A method for producing lithium carbonate, according to the present invention, comprises the steps of: preparing an ore containing lithium; calcining the ore containing lithium; mixing the calcined ore containing lithium with sodium carbonate and water and performing high-temperature high-pressure leaching so as to obtain a leachate containing lithium carbonate particles; bicarbonating the leachate so as to obtain a lithium bicarbonate aqueous solution; solid-liquid separating the lithium bicarbonate aqueous solution so as to obtain a lithium bicarbonate filtrate and a residue; mixing the residue with hydrochloric acid so as to obtain sodium chloride; subjecting the sodium chloride to an electrochemical reaction; and carbonating sodium hydroxide obtained after the electrochemical reaction.

The invention relates to a method for recycling waste batteries leached through reduction roasting of ternary battery powder. Comprising the following steps: reduction roasting: mixing ternary battery black powder and carbon powder, and roasting for 1 hour in a nitrogen atmosphere; on the premise of lithium, water is added into the roasted material for slurrying, carbon dioxide is introduced for a closed pressurized reaction for 4-8 h, filter residues are filtered out, and the main component of filtrate is lithium bicarbonate; acid leaching: adding water into the filter residue, slurrying, adding sulfuric acid to adjust the pH value, reacting for 4-6 hours at the temperature of 80-90 DEG C, filtering, completely leaching nickel, cobalt, manganese and lithium, and taking the filter residue as waste graphite; after roasting, CO2 is directly introduced for water leaching, lithium bicarbonate is generated, other metal impurities are basically not introduced, lithium carbonate can be generated without impurity removal and heating decomposition, lithium loss in the impurity removal process is reduced, the whole lithium precipitation process flow is shortened, the lithium recovery rate is increased by about 2%, meanwhile, introduction of impurities is avoided, the lithium purity is guaranteed, and the lithium recovery rate is increased by about 2%. And industrial production is facilitated.

The present application relates to a kind of surface carbonation modified iron-doped nickel oxide preparation method and the method of decomposing ozone, the preparation method comprises the following steps: adding precipitant to the aqueous solution of nickel-containing iron precursor, hydrothermal reaction is carried out, precursor material nickel-iron layered double hydroxide is obtained, calcination, the aqueous solution of the obtained iron-doped nickel oxide and modifier is mixed uniformly, hydrothermal reaction is carried out;Wherein, the modifier is one or more of urea, ammonium carbonate, ammonium bicarbonate, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, lithium carbonate, lithium bicarbonate, sodium hydroxide, potassium hydroxide and lithium hydroxide.The preparation method of the present application is simple, does not need special condition, and the iron-doped nickel oxide catalyst modified by surface carbonation is rich in active site, and can show high and stable ozone decomposition efficiency in high humidity or extremely high humidity environment.

A method of extracting lithium, the method comprising the steps of subjecting a lithium-containing material to a leaching process in the presence of carbonate ions at atmospheric pressure and elevated temperatures above 50 DEG C but below 160 DEG C to produce a leach slurry containing lithium carbonate; performing a carbonation process on the leached slurry to convert at least a portion of the lithium carbonate to lithium bicarbonate; performing a solid-liquid separation process on the leaching slurry to separate leaching residues from the leaching solution; solid lithium carbonate is obtained from the leaching solution; and separating solid lithium carbonate from the leaching solution.

The invention provides a lithium bicarbonate thermal decomposition system, which belongs to the technical field of lithium carbonate production, and comprises a preheater, a pyrolysis tower, a steam utilization assembly and a dense separation assembly, the interior of the preheater is used for introducing a lithium bicarbonate solution and indirectly preheating the lithium bicarbonate solution by using a high-temperature fluid; the pyrolysis tower is connected with the preheater, the pyrolysis tower is connected with a first heater in parallel, and the interior of the first heater is used for introducing high-temperature steam to indirectly heat a lithium bicarbonate solution, so that the lithium bicarbonate solution is decomposed into lithium carbonate slurry and mixed steam; the steam utilization assembly is connected with the pyrolysis tower and the first heater, so that the first heater indirectly heats the lithium bicarbonate solution; and the dense separation assembly is connected with the pyrolysis tower and is used for thickening the lithium carbonate slurry and separating out pure lithium carbonate. According to the lithium bicarbonate thermal decomposition system provided by the invention, the lithium bicarbonate solution is heated by recycling mixed steam generated by pyrolysis, so that the energy utilization rate is increased, and the operation cost of the system is reduced.

The present application relates to a method for co-production of lithium carbonate series products from lithium-containing solution. The method uses purified sodium carbonate solution to precipitate lithium carbonate, which is then converted into lithium bicarbonate solution, filtered and decarburized, and through optimization of conventional purification process steps and parameters, high-purity lithium carbonate, battery-grade lithium carbonate and industrial-grade lithium carbonate products are obtained without introducing additional high-cost purification steps such as ion exchange resin / membrane. The process maximizes the use of lithium-containing solution, shortens the process flow and time, and has good economic benefits. At the same time, the by-products of each stage of the scheme can be reused, only a small amount of waste solution is produced, which can realize the recycling of mother liquor, improve the comprehensive yield of products, and effectively reduce the comprehensive cost.