CN111960446B - Method for continuously producing high-purity lithium carbonate - Google Patents
Method for continuously producing high-purity lithium carbonate Download PDFInfo
- Publication number
- CN111960446B CN111960446B CN202010943455.2A CN202010943455A CN111960446B CN 111960446 B CN111960446 B CN 111960446B CN 202010943455 A CN202010943455 A CN 202010943455A CN 111960446 B CN111960446 B CN 111960446B
- Authority
- CN
- China
- Prior art keywords
- pyrolysis
- lithium carbonate
- hydrogenation
- liquid
- purity
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
- C01D15/00—Lithium compounds
- C01D15/08—Carbonates; Bicarbonates
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/80—Compositional purity
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/141—Feedstock
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
The invention belongs to the field of inorganic salt chemical industry, and relates to a method for continuously producing high-purity lithium carbonate, which comprises the processes of pulping, hydrogenation, filtration, pyrolysis and the like, wherein the temperature of a reaction kettle is kept relatively constant in the pyrolysis process, 1/4-1/3 of pyrolysis base solution is reserved in the reaction kettle, and the dropping flow rate of the hydrogenation solution is controlled to pyrolyze the hydrogenation solution; compared with the prior art that the temperature of the reaction kettle needs to be repeatedly increased and decreased, the temperature of the reaction kettle does not need to be increased and decreased in the pyrolysis process, and the waiting time generated in the temperature increasing and decreasing process of the reaction kettle does not exist, so that the pyrolysis process can be continuously performed, the continuous production can be realized by using the method, and the energy consumption is low.
Description
Technical Field
The invention belongs to the field of inorganic salt chemical industry, relates to a preparation method of high-purity lithium carbonate, and particularly relates to a method for continuously producing high-purity lithium carbonate.
Background
The high-purity lithium carbonate is widely applied to the fields of electronic materials, medicines, reagents and the like, and particularly the demand of the field of electronic materials is rapidly increased; in the field of electronic materials, high-purity lithium carbonate is used as a solid wave vibration element, and the material used in the element is lithium niobate and lithium tantalate single crystals, and the lithium niobate and lithium tantalate are made of niobium pentoxide, tantalum pentoxide and high-purity lithium carbonate. Lithium tantalate can also be used in thermoelectric detection elements, military, medical, fire alarm, disaster prevention and other fields. In addition, the dosage of reagents and medicines is continuously expanded, and the market prospect is good.
The preparation process of high-purity lithium carbonate is always the focus of research, the currently commonly used method is basically the same as the method for preparing battery-grade lithium carbonate, and is three main steps of hydrogenation, ion exchange impurity removal and pyrolysis, for example, a patent with the publication number of CN102531002B discloses a method for purifying lithium carbonate, lithium carbonate is purified by hydrogenation, ion exchange and pyrolysis, in the pyrolysis process, the inventor finds that the temperature rise rate has great influence on the main content of the product, when the temperature rise rate exceeds 1 ℃/min, the precipitated product particles are obviously larger than the product obtained by slow heating, and the product particles are wrapped by impurities, so that the main content of the product is reduced, and aiming at the phenomenon, the temperature rise rate needs to be strictly controlled between 0.5 and 1 ℃/min in the pyrolysis process. That is, before pyrolysis, the temperature in the reaction kettle needs to be reduced to room temperature, and hydrogenation liquid is added into the reaction kettleAnd then, strictly controlling the temperature of the reaction kettle to be raised to 70-90 ℃ for pyrolysis, and because the reaction kettle needs to be repeatedly raised and lowered in temperature, the method disclosed by the patent cannot realize continuous production and has high energy consumption. In addition, as can be seen from the examples section of this patent, the purity of lithium carbonate purified by this method is between 99.81% and 99.86%, and the purity requirement of high-purity lithium carbonate cannot be met (Li) 2 CO 3 The content is more than or equal to 99.90 percent).
In addition, a patent with publication number CN109942009A discloses a preparation method of battery-grade lithium carbonate, wherein a packed tower device is adopted to be connected in series, and a mode of gas-liquid countercurrent contact is adopted to increase lithium carbonate slurry and CO 2 The contact area and the chemical reaction power of the gas improve the hydrogenation rate of the lithium carbonate, and the content of sulfate radicals in the product is reduced by adding a sulfate radical complexing agent into a reaction system in the pyrolysis process; the sodium hydroxide solution is used for washing in the washing process, the polycrystalline structure is damaged, the impurity content is reduced, and the prepared lithium carbonate reaches the standard of industrial battery-grade lithium carbonate products (Li is more than or equal to 99.50%) 2 CO 3 The content is less than 99.90%), but because the method additionally introduces a sulfate radical complexing agent and sodium hydroxide into the system, namely other impurities are introduced into the reaction system, the purity of the lithium carbonate prepared by the method cannot be further improved by repeatedly extracting the lithium mother liquor, namely the purity of the lithium carbonate prepared by the method can reach the battery level and cannot meet the purity requirement of high-purity lithium carbonate (the Li can not reach the battery level) 2 CO 3 The content is more than or equal to 99.90 percent). In addition, as can be seen from the disclosure of the patent specification, in the pyrolysis process, the temperature needs to be controlled to be above 70 ℃, and the heating temperature rise process is not less than 30min, that is, in the pyrolysis process, the temperature rise rate also needs to be controlled, that is, in the pyrolysis process, repeated temperature rise and drop operations need to be performed on the reaction kettle, which is not convenient for continuous production of lithium carbonate.
In summary, the existing lithium carbonate purification methods all require repeated temperature rise and drop operations on the reaction kettle in the pyrolysis process, which is not beneficial to the continuous production of lithium carbonate and has high energy consumption; in addition, external impurities are often introduced in the purification process of the existing lithium carbonate, which is not beneficial to further improvement of the purity of the lithium carbonate.
Disclosure of Invention
The invention aims to provide a method for continuously producing high-purity lithium carbonate, which has the advantages of low energy consumption in the preparation process and high purity of the prepared lithium carbonate.
Based on the purpose, the invention adopts the following technical scheme: a method for continuously producing high-purity lithium carbonate comprises the following steps:
(1) Uniformly mixing industrial-grade lithium carbonate and water according to the proportion of 1g (18-25) mL to prepare slurry;
(2) Equally dividing and packing the slurry liquid into a plurality of hydrogenation towers which are connected in series; continuously introducing high-purity CO into the hydrogenation tower from the bottoms of the two hydrogenation towers arranged at two ends respectively 2 Hydrogenating to obtain hydrogenated liquid; the hydrogenation tower has no exhaust gas in the hydrogenation process, so that the introduced high-purity carbon dioxide is fully utilized in the hydrogenation towers which are connected in series;
(3) Filtering the obtained hydrogenated liquid to remove insoluble impurities;
(4) Adding the hydrogenated liquid filtered in the step (3) into a pyrolysis container to serve as pyrolysis base liquid, wherein the volume of the pyrolysis base liquid is 1/4-1/3 of the pyrolysis capacity of the pyrolysis container; adding high-purity 4N-grade lithium carbonate into the pyrolysis base solution, controlling the temperature in a pyrolysis container to be 98-100 ℃, slowly dropwise adding the filtered hydrogenation solution into the pyrolysis container to pyrolysis capacity, carrying out heat preservation reaction at the temperature of 98-100 ℃ for 0.5-1 h to prepare pyrolysis solution, releasing 2/3-3/4 volume of pyrolysis solution, filtering, collecting and precipitating, washing the precipitate, and calcining at the temperature of 450 ℃ to prepare high-purity lithium carbonate; the residual pyrolysis liquid in the pyrolysis container is used as pyrolysis base liquid for the next reaction;
(5) Slowly dripping the hydrogenated liquid filtered in the step (3) into the residual pyrolysis liquid in the pyrolysis container in the step (4) to pyrolysis capacity, reacting for 0.5-1 h at the temperature of 98-100 ℃ to prepare pyrolysis liquid, releasing 2/3-3/4 volume of pyrolysis liquid, filtering, collecting precipitate, washing the precipitate, and calcining at 450 ℃ to prepare high-purity lithium carbonate; the residual pyrolysis liquid in the pyrolysis container is continuously used as pyrolysis base liquid for the next reaction;
(6) And (5) repeating the steps (1) to (5) to continuously produce the high-purity lithium carbonate.
Further, CO in step (2) 2 The introduction rate of the catalyst is based on the volume of the slurry liquid in the hydrogenation tower connected with the catalyst, and each liter of the slurry liquid corresponds to CO 2 The feeding rate of (2) is 0.1-0.8L/min.
Further, each liter of the slurry solution corresponds to CO 2 The feeding rate of (2) is 0.2-0.6L/min.
Further, each liter of the slurry solution corresponds to CO 2 The feed rate of (2) was 0.3L/min.
Further, in the process of slowly dripping the filtered hydrogenation solution into the pyrolysis container in the step (4) and the step (5), the volume of the dripping hydrogenation solution per minute is 0.5-2% of the pyrolysis capacity.
Further, 2/3 volume of pyrolysis liquid released when the pyrolysis is completed in the step (4) and the step (5) is filtered to prepare high-purity lithium carbonate, and 1/3 volume of pyrolysis liquid is reserved as pyrolysis base liquid of the next reaction.
Further, the high-purity 4N-grade lithium carbonate and the pyrolysis base solution in the step (4) are added into the pyrolysis base solution according to the proportion of (1-2) g: 1L.
Further, the ratio of the industrial-grade lithium carbonate to the water in the step (1) is 1g (20-23) mL.
Further, the ratio of industrial-grade lithium carbonate to water in step (1) is 1g.
Further, the number of the hydrogenation towers connected in series in the step (2) is 3 to 10.
Further, the number of hydrogenation columns connected in series to each other is 4 to 6, more preferably 5.
Further, the filter pore size of the filter used for the filtration in the step (3) is 0.1 to 1 μm.
Compared with the prior art, the invention has the beneficial effects that:
(1) The invention keeps the temperature of the reaction kettle relatively constant in the pyrolysis process, and 1/4-1/3 of pyrolysis base solution is kept in the reaction kettle, and the dropping flow rate of the hydrogenation solution is controlled to pyrolyze the hydrogenation solution; compared with the prior art that the temperature of the reaction kettle needs to be repeatedly increased and decreased, the temperature of the reaction kettle does not need to be increased and decreased in the pyrolysis process of the method, and the waiting time generated in the temperature increasing and decreasing process of the reaction kettle does not exist, so that the method can continuously perform the pyrolysis process, continuous production can be realized by using the method, and the energy consumption is low.
(2) The invention prepares high-purity lithium carbonate by pulping, hydrogenating, filtering and pyrolyzing industrial-grade lithium carbonate, and no external impurity is introduced in the preparation process, so that the lithium carbonate with higher purity can be prepared after repeated purification by the purification method of the invention, and the purity of the lithium carbonate prepared by three-time purification by the method of the invention is not lower than 99.99 percent by taking the industrial-grade lithium carbonate with the purity of 98.4 percent as an example, therefore, the quality of the lithium carbonate prepared by the method of the invention is superior to the standard of the purity of the lithium carbonate of 99.99 percent specified in YS/T546-2008 in the color industry.
(3) The invention adopts a plurality of hydrogenation towers which are connected in series end to end, carbon dioxide is introduced into the hydrogenation towers which are connected in series through the bottoms of the two hydrogenation towers which are arranged at two ends, the carbon dioxide enters the interior of the next hydrogenation tower through a pipeline which is communicated with the bottom of the next hydrogenation tower through the top, namely the carbon dioxide is introduced from the bottoms of the hydrogenation towers, so that the carbon dioxide and the hydrogenation liquid flow in the reverse direction and are fully contacted for hydrogenation reaction, and no exhaust is arranged in the hydrogenation process, so that the introduced carbon dioxide can be fully and effectively utilized, and the utilization rate of the carbon dioxide and the hydrogenation efficiency are improved.
(4) According to the invention, the same amount of slurry liquid is filled in the hydrogenation towers which are connected in series, and carbon dioxide with the same flow rate is introduced from the hydrogenation towers at two ends, so that the hydrogenation completion time of the two hydrogenation towers at two ends is similar, the amount of the hydrogenated liquid after hydrogenation can meet the continuous pyrolysis requirement of a reaction kettle, and the continuous production of high-purity lithium carbonate is facilitated.
Drawings
FIG. 1 is a schematic view of the process of the present invention.
Detailed Description
Example 1 investigation of different CO 2 The manner of introduction and the influence of the rate of introduction on the hydrogenation efficiency
A method for continuously producing high-purity lithium carbonate, as shown in fig. 1, comprising the following steps:
(1) Industrial-grade lithium carbonate and ultrapure water were mixed in a proportion of 1g to 20ml to prepare 75L of slurry, where the main content and impurity content of industrial-grade lithium carbonate in this example are shown in table 1, and the content of lithium carbonate in industrial-grade lithium carbonate was 99.4%.
(2) The slurry is equally divided and packed in five hydrogenation towers which are sequentially connected in series end to end, namely the top of the former hydrogenation tower is connected with the bottom of the latter hydrogenation tower through a ventilation pipeline for CO in the hydrogenation process 2 Gas transmission; the volume of the slurry in each hydrogenation tower is 15L; continuously introducing high-purity CO into the hydrogenation tower from the bottoms of the two hydrogenation towers arranged at two ends respectively 2 Hydrogenating to obtain hydrogenated liquid; the hydrogenation tower has no exhaust gas in the hydrogenation process, so that the introduced high-purity carbon dioxide is fully utilized in the hydrogenation towers which are connected in series; CO in hydrogenation tower arranged at two ends 2 The feeding rate of the hydrogenation tower is determined by the volume of the slurry liquid in a single hydrogenation tower and is positively correlated with the volume of the slurry liquid; CO control according to volume of slurry liquid added into hydrogenation tower 2 The rate of passage of (1).
(3) The obtained hydrogenated liquid was filtered through a microfilter having a filtration pore size of 0.22 μm to remove insoluble impurities.
(4) Adding 1/3 volume of hydrogenation liquid filtered in the step (3) into a pyrolysis container to serve as pyrolysis base liquid, wherein the capacity of the pyrolysis container is 15L, and the amount of the hydrogenation liquid added as primary pyrolysis base liquid is 5L; adding high-purity 4N-grade lithium carbonate (the purity of lithium carbonate is more than or equal to 99.99%) into the pyrolysis base solution, wherein the ratio of the added high-purity 4N-grade lithium carbonate to the pyrolysis base solution is 1g; and controlling the temperature in the pyrolysis container to be 100 ℃, slowly dripping the filtered hydrogenation liquid into the pyrolysis container to pyrolysis capacity, wherein the dripping flow rate of the hydrogenation liquid is 0.11L/min, namely dripping 10L of the hydrogenation liquid to be dripped is completed within about 1.5h, and if the volume of the hydrogenation liquid dripped per minute is 0.73% of the pyrolysis capacity according to the pyrolysis capacity.
Then, reacting for 1 hour at 100 ℃ to obtain pyrolysis liquid, releasing 2/3 volume of pyrolysis liquid, filtering, collecting precipitate, washing the precipitate with organic alcohol such as absolute ethyl alcohol or absolute methyl alcohol, or glycerol or n-butyl alcohol, filtering, drying, and calcining at 450 ℃ to obtain high-purity lithium carbonate; the residual pyrolysis liquid in the pyrolysis container is used as pyrolysis base liquid for the next reaction; the reaction kettle adopts an oil bath heating mode in the pyrolysis process, so that the heat preservation performance of oil bath heating is better and the heat loss is effectively avoided compared with steam heating or electric heating.
(5) Dropwise adding the hydrogenated liquid filtered in the step (3) into the residual pyrolysis liquid in the pyrolysis container in the step (4) at the flow rate of 0.11L/min to the pyrolysis capacity, keeping the temperature and reacting for 1h at 100 ℃ to obtain pyrolysis liquid, releasing 2/3 volume of pyrolysis liquid, filtering, collecting precipitate, washing the precipitate, and calcining at 450 ℃ to obtain high-purity lithium carbonate; the residual pyrolysis liquid in the pyrolysis container is continuously used as pyrolysis base liquid for the next reaction.
(6) And (5) repeating the steps (1) to (5) to continuously produce the high-purity lithium carbonate.
Referring to the method for continuously producing high-purity lithium carbonate in the steps (1) to (6), high-purity lithium carbonate is prepared according to specific parameters given in table 2 and is respectively recorded as samples 1-1 to 1-7.
Referring to the continuous production process of high purity lithium carbonate in steps (1), (3) to (6) and the preparation of the comparative sample with the parameters given in table 2, the preparation process of the comparative sample differs from that of samples 1-1 to 1-7 in step (2).
The step (2) in the preparation process of the comparison sample is as follows: the pulp liquid is equally divided and packed into five mutually connected in series end to endIn the hydrogenation column (2), i.e. the top of the preceding hydrogenation column is connected to the bottom of the succeeding hydrogenation column via a vent line for conducting CO during the hydrogenation 2 Gas transmission; the volume of the slurry in each hydrogenation tower is 15L; continuously introducing high-purity CO into the hydrogenation tower from the bottom of the first hydrogenation tower 2 High purity CO 2 Sequentially conveying the mixture from the first hydrogenation tower to the last hydrogenation tower, escaping from the top of the last hydrogenation tower, introducing the mixture into the bottom of the first hydrogenation tower, and carrying out high-purity CO 2 The slurry liquid in the hydrogenation tower is subjected to hydrogenation reaction to prepare hydrogenation liquid; CO 2 2 The feeding speed of the reactor is determined by the volume of the slurry liquid in a single hydrogenation tower and is positively correlated with the volume of the slurry liquid; CO control according to the volume of the slurry liquid added into the hydrogenation tower 2 The rate of passage of (1).
Setting different CO in hydrogenation reaction process 2 Observing CO at different flow rates 2 For hydrogenation completion time, CO 2 The effect of (a) on the utilization rate and hydrogenation efficiency is shown in table 2, wherein the hydrogenation time refers to the time taken for the slurry in the five hydrogenation columns in series to completely complete hydrogenation.
As is clear from the results of samples 1-1 to 1-7 in Table 2, the following CO was added 2 Increase in the feed rate and decrease in the hydrogenation time, but CO 2 The utilization rate of (2) is in a descending trend; from the results of samples 1-2 and the comparative sample, it can be seen that the same CO is used 2 Under the condition of the feeding rate, compared with the comparative sample, the hydrogenation time of the sample 1-2 is shortened by 37%, and CO is reduced 2 The utilization rate of the method is improved by 35 percent.
Example 2 discussion of the effect of different hydrogenation solution drop rates on the purity of lithium carbonate produced
A method for continuously producing high-purity lithium carbonate comprises the following steps:
(1) Industrial-grade lithium carbonate and ultrapure water were mixed uniformly in a proportion of 1g to 25ml, to prepare 100L of slurry, wherein the content of lithium carbonate in the industrial-grade lithium carbonate in this example was 99.0%.
(2) The slurry is equally divided and packed in five hydrogenation towers which are sequentially connected in series end to end, namely the top of the former hydrogenation tower is connected with the bottom of the latter hydrogenation tower through a ventilation pipeline for CO in the hydrogenation process 2 Gas transmission; the volume of the slurry in each hydrogenation tower is 20L; continuously introducing high-purity CO from the bottom of the first hydrogenation tower into the hydrogenation towers connected in series 2 CO escaping from the last hydrogenation column 2 The gas is returned to the first hydrogenation tower and is introduced from the bottom of the first hydrogenation tower, so that CO is in the hydrogenation tower 2 The gas and the slurry liquid are in countercurrent contact, and the slurry liquid is hydrogenated to prepare hydrogenated liquid in such a circulating way; the hydrogenation tower has no exhaust gas in the hydrogenation process, so that the introduced high-purity carbon dioxide is fully utilized in the hydrogenation towers which are connected in series; CO in hydrogenation tower 2 The feeding rate of the hydrogenation tower is determined by the volume of the slurry liquid in a single hydrogenation tower and is positively correlated with the volume of the slurry liquid; introducing CO into the hydrogenation tower 2 At a rate of 4L/min, i.e. CO per liter of slurry in a single hydrogenation column 2 The feed rate of (2) was 0.2L/min.
(3) The obtained hydrogenation solution was filtered through a microfilter having a filtration pore size of 0.1 μm to remove insoluble impurities.
(4) Adding 1/4 volume of hydrogenation liquid filtered in the step (3) into a pyrolysis container to serve as pyrolysis base liquid, wherein the capacity of the pyrolysis container is 20L, and the amount of the hydrogenation liquid added as primary pyrolysis base liquid is 5L; adding high-purity 4N-grade lithium carbonate (the purity of lithium carbonate is more than or equal to 99.99%) into the pyrolysis base solution, wherein the ratio of the added high-purity 4N-grade lithium carbonate to the pyrolysis base solution is 1g; controlling the temperature in the pyrolysis container to be 100 ℃, slowly dripping the filtered hydrogenation solution into the pyrolysis container to reach pyrolysis capacity, and controlling the dripping flow rate of the hydrogenation solution, wherein the dripping flow rate of the hydrogenation solution is shown in table 2.
Then, reacting for 1 hour at 100 ℃ to obtain pyrolysis liquid, releasing 4/5 volume of pyrolysis liquid, filtering, collecting precipitate, namely releasing 15L of pyrolysis liquid, filtering, collecting precipitate, washing the precipitate with organic alcohol such as absolute ethyl alcohol or absolute methyl alcohol, or glycerol or n-butyl alcohol, filtering, drying, and calcining at 450 ℃ to obtain high-purity lithium carbonate; the remaining 5L of pyrolysis liquid in the pyrolysis container is used as pyrolysis bottom liquid for the next reaction; at pyrolysis in-process reation kettle adopts the oil bath heating mode, for steam heating or electrical heating, the thermal insulation performance of oil bath heating is better, effectively avoids calorific loss.
(5) Adding 15L of the hydrogenated liquid filtered in the step (3) into the residual pyrolysis liquid in the pyrolysis container in the step (4) according to the same dropwise adding flow rate of the hydrogenated liquid in the step (4) to the pyrolysis capacity of 20L, carrying out heat preservation reaction at 100 ℃ for 1h to obtain pyrolysis liquid, releasing 15L of the pyrolysis liquid, filtering, collecting precipitate, washing the precipitate, and calcining at 450 ℃ to obtain high-purity lithium carbonate; the remaining 5L of pyrolysis liquid in the pyrolysis container continues to be used as pyrolysis base liquid for the next reaction.
(6) And (6) repeating the steps (1) to (5) to continuously produce the high-purity lithium carbonate.
The dropping flow rates of different hydrogenation solutions were set during the pyrolysis, and the influence of the hydrogenation solutions with different dropping flow rates on the purity of lithium carbonate finally obtained by purification was observed, and the dropping flow rates of the hydrogenation solutions and the purity of lithium carbonate finally obtained by purification are shown in table 3.
As can be seen from Table 3, when the acceleration of the hydrogenation liquid drop is 0.6-1.5% of the pyrolysis capacity, the dropping time is completed to 50-125min, i.e. the reaction time is short, and the purity of the obtained lithium carbonate is higher than 99.994%; when the dropping speed is more than 1.5 percent of the pyrolysis capacity, the dropping time is less than 50min, and the obtained lithium carbonate barely reaches the 4N-grade purity; when the dropping speed is 0.1 percent of the pyrolysis capacity, the dropping completion time is 750min, and the hydrogenation solution is reacted at the high temperature of 95 ℃ all the time, so that a large amount of hydrogenation solution is evaporated in a long time to reduce the liquid volume, impurities are enriched in lithium carbonate, and the content is reduced.
Example 3
A method for continuously producing high-purity lithium carbonate comprises the following steps:
(1) And uniformly mixing industrial-grade lithium carbonate and ultrapure water according to a certain proportion to prepare 200L of slurry.
(2) Equally dividing the slurry into five hydrogenation towers which are connected in series end to end, wherein the slurry amount in each hydrogenation tower is 40L; the top of the former hydrogenation tower is connected with the bottom of the latter hydrogenation tower through a pipeline for carrying out CO in the hydrogenation process 2 Gas transmission; continuously introducing high-purity CO into the hydrogenation tower from the bottoms of the two hydrogenation towers arranged at two ends respectively 2 Hydrogenating to obtain hydrogenated liquid; the hydrogenation tower has no exhaust gas in the hydrogenation process, so that the introduced high-purity carbon dioxide is fully utilized in the hydrogenation towers which are connected in series; CO in hydrogenation tower arranged at two ends 2 The feeding rate of the hydrogenation tower is determined by the volume of the slurry liquid in a single hydrogenation tower and is positively correlated with the volume of the slurry liquid; CO control according to the volume of the slurry liquid added into the hydrogenation tower 2 The introduction rate of (2), CO per liter of slurry 2 The introduction rate of (2) was 0.3L/min, that is, CO introduced from each of the two hydrogenation columns at both ends 2 The flow rates of (A) and (B) were all 6L/min.
(3) The obtained hydrogenated liquid was filtered through a microfilter having a filtration pore size shown in table 3 to remove insoluble impurities.
(4) Adding 1/4 volume of hydrogenation liquid filtered in the step (3) into a pyrolysis container as pyrolysis base liquid, wherein the volume of the pyrolysis container is 40L, and the amount of the added hydrogenation liquid is 10L; adding high-purity 4N-grade lithium carbonate (the purity of lithium carbonate is more than or equal to 99.99%) into the pyrolysis base solution, wherein the proportion of the added high-purity 4N-grade lithium carbonate to the pyrolysis base solution is 1g; and controlling the temperature in the pyrolysis container to be 100 ℃, slowly dripping the filtered hydrogenation liquid into the pyrolysis container to pyrolysis capacity, wherein the dripping flow rate of the hydrogenation liquid is 0.25L/min, namely dripping 30L of the hydrogenation liquid to be dripped is completed within 2h, and if the volume of the hydrogenation liquid dripped per minute is 0.625% of the pyrolysis capacity according to the pyrolysis capacity.
Then, reacting for 1 hour at 100 ℃ for heat preservation to obtain pyrolysis liquid, releasing 3/4 volume of pyrolysis liquid, filtering, collecting precipitate, washing the precipitate with organic alcohol such as absolute ethyl alcohol or absolute methyl alcohol, or glycerol or n-butyl alcohol, filtering, drying, and calcining at 450 ℃ to obtain high-purity lithium carbonate; and the residual pyrolysis liquid in the pyrolysis container is used as pyrolysis base liquid for the next reaction.
(5) Dropwise adding the hydrogenated liquid filtered in the step (3) into the residual pyrolysis liquid in the pyrolysis container in the step (4) at the flow rate of 0.25L/min to the pyrolysis capacity, keeping the temperature and reacting for 1h at 100 ℃ to obtain pyrolysis liquid, releasing 3/4 of the volume of the pyrolysis liquid, filtering and collecting precipitate, washing the precipitate, and calcining at 450 ℃ to obtain high-purity lithium carbonate; and the residual pyrolysis liquid in the pyrolysis container is continuously used as pyrolysis base liquid for the next reaction.
(6) And (5) repeating the steps (1) to (5) to continuously produce the high-purity lithium carbonate.
The parameters in the preparation process and the purity of the high-purity lithium carbonate prepared by the steps are shown in table 4, wherein the purification times are the times of the industrial-grade lithium carbonate raw material passing through the purification processes in the steps (1) to (6), the purity of the lithium carbonate is calculated according to a method specified in the industrial standard compilation of high-purity lithium carbonate (2019 pre-examination), and the impurity measurement is carried out according to GB/T11064.16-2013.
As can be seen from Table 3, after the industrial-grade lithium carbonates with different purities are repeatedly purified by the method, the purities of the prepared lithium carbonates are all higher than 99.99%, which is higher than the standard that the purity of the lithium carbonate is 99.99% specified in YS/T546-2008 in the color industry.
Claims (8)
1. A method for continuously producing high-purity lithium carbonate is characterized by comprising the following steps:
(1) Uniformly mixing industrial-grade lithium carbonate and water according to the proportion of 1g (18-25) mL to prepare slurry;
(2) Equally dividing and packing the slurry liquid into a plurality of hydrogenation towers which are connected in series; continuously introducing high-purity CO into the hydrogenation towers connected in series from the bottoms of the two hydrogenation towers arranged at two ends respectively 2 Hydrogenating to obtain hydrogenated liquid; CO 2 2 The introduction rate of the catalyst is based on the volume of the slurry liquid in the hydrogenation tower connected with the catalyst, and each liter of the slurry liquid corresponds to CO 2 The feeding rate of (2) is 0.1-0.8L/min;
(3) Filtering the obtained hydrogenated liquid to remove insoluble impurities;
(4) Adding the hydrogenated liquid filtered in the step (3) into a pyrolysis container to serve as pyrolysis base liquid, wherein the volume of the pyrolysis base liquid is 1/4-1/3 of the pyrolysis capacity of the pyrolysis container; adding high-purity 4N-grade lithium carbonate into the pyrolysis base solution, controlling the temperature in a pyrolysis container to be 98-100 ℃, dropwise adding filtered hydrogenation solution into the pyrolysis container to pyrolysis capacity, carrying out heat preservation reaction at the temperature of 98-100 ℃ for 0.5-1 h to prepare pyrolysis solution, releasing 2/3-3/4 volume of pyrolysis solution, filtering, collecting precipitate, washing the precipitate, and calcining at the temperature of 450 ℃ to prepare high-purity lithium carbonate; the residual pyrolysis liquid in the pyrolysis container is used as pyrolysis base liquid for the next reaction;
(5) Dropwise adding the hydrogenated liquid filtered in the step (3) into the residual pyrolysis liquid in the pyrolysis container in the step (4) to pyrolysis capacity, reacting at the temperature of 98-100 ℃ for 0.5-1 h to prepare pyrolysis liquid, releasing 2/3-3/4 volume of pyrolysis liquid, filtering, collecting and precipitating, washing the precipitate, and calcining at the temperature of 450 ℃ to prepare high-purity lithium carbonate; the residual pyrolysis liquid in the pyrolysis container is continuously used as pyrolysis base liquid for the next reaction;
(6) And (5) repeating the steps (1) to (5) to continuously produce the high-purity lithium carbonate.
2. The method for continuously producing high-purity lithium carbonate according to claim 1, wherein the CO is corresponding to each liter of slurry 2 The feeding rate of (2) is 0.2-0.6L/min.
3. The method for continuously producing high-purity lithium carbonate according to any one of claims 1 to 2, wherein, in the step (4) and the step (5), during the slow dropwise addition of the filtered hydrogenation solution into the pyrolysis container, the volume of the hydrogenation solution dropwise added per minute is 0.5 to 2% of the pyrolysis capacity.
4. The continuous production method of high-purity lithium carbonate according to claim 3, wherein the high-purity 4N grade lithium carbonate in the step (4) is mixed with the pyrolysis base solution according to the proportion of (1-2) g: 1L.
5. The continuous production method of high-purity lithium carbonate according to claim 4, wherein the ratio of the industrial-grade lithium carbonate to the water in the step (1) is 1g (20-23) mL.
6. The continuous production method of high-purity lithium carbonate according to claim 5, wherein the number of the hydrogenation towers which are connected in series in the step (2) is 3 to 10.
7. The method for continuously producing high-purity lithium carbonate according to claim 6, wherein the number of the hydrogenation towers connected in series is 4-6.
8. The continuous production method of high-purity lithium carbonate according to claim 7, wherein the filter used for the filtration in the step (3) has a filter pore size of 0.1-1 μm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010943455.2A CN111960446B (en) | 2020-09-09 | 2020-09-09 | Method for continuously producing high-purity lithium carbonate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010943455.2A CN111960446B (en) | 2020-09-09 | 2020-09-09 | Method for continuously producing high-purity lithium carbonate |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111960446A CN111960446A (en) | 2020-11-20 |
| CN111960446B true CN111960446B (en) | 2023-02-21 |
Family
ID=73392809
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010943455.2A Active CN111960446B (en) | 2020-09-09 | 2020-09-09 | Method for continuously producing high-purity lithium carbonate |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111960446B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114477245A (en) * | 2022-02-24 | 2022-05-13 | 宁夏天霖新材料科技有限公司 | Method for preparing lithium carbonate of battery by continuously carbonizing industrial-grade lithium carbonate |
| CN115893454B (en) * | 2022-11-01 | 2023-06-09 | 甘肃睿思科新材料有限公司 | Method for efficiently producing ultrapure lithium carbonate with uniform and stable granularity |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103833053B (en) * | 2014-01-21 | 2015-12-30 | 四川天齐锂业股份有限公司 | Prepare the method for 5N level pure Lithium Carbonate |
| CN109942009B (en) * | 2019-04-26 | 2021-08-17 | 核工业北京化工冶金研究院 | Preparation method of battery-grade lithium carbonate |
-
2020
- 2020-09-09 CN CN202010943455.2A patent/CN111960446B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN111960446A (en) | 2020-11-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111960446B (en) | Method for continuously producing high-purity lithium carbonate | |
| CN102659144B (en) | Method for preparing high purity level lithium hydroxide monohydrate | |
| CN114105172B (en) | Method for producing high-purity lithium carbonate by causticizing and carbonizing crude lithium carbonate lime | |
| CN102198937B (en) | Static multistage melting crystallization method for preparing electronic grade phosphoric acid | |
| EP4230278A1 (en) | Method for recovering lithium from lithium precipitation mother liquor | |
| CN111892071B (en) | Method for purifying lithium carbonate | |
| CN114477245A (en) | Method for preparing lithium carbonate of battery by continuously carbonizing industrial-grade lithium carbonate | |
| CN112919504B (en) | Method and device for synthesizing lithium hexafluorophosphate by adopting continuous flow reactor | |
| CN112516616A (en) | Crystallization device and method for purifying ethylene carbonate | |
| CN109534369B (en) | Membrane integrated lithium chloride preparation equipment and method thereof | |
| CN103172122A (en) | Method for purifying high purity ammonium rhenate from liquid containing ammonium rhenate | |
| CN112516615A (en) | Device and method for crystallization purification | |
| CN106349057A (en) | Treatment process for deferrization purification of sodium citrate mother liquor | |
| CN107473242B (en) | A method of high-purity lithium oxide is prepared using lithium carbonate | |
| CN206735809U (en) | A kind of production system of electronic-grade polycrystalline silicon | |
| CN115650243A (en) | Method for separating and recovering fluorine and silicon in fluorine-containing silicon slag in one step | |
| CN101624343B (en) | Hydrogen recycling method and device of refining unit of pure terephthalic acid device | |
| CN1313431C (en) | Method of preparing metal ion less adipic acid by nitric acid oxidation of cyclohexane oxidation liquid pickling water | |
| CN117361570B (en) | Method for preparing battery grade sodium fluoride from sodium carbonate and sodium fluosilicate | |
| CN111517367A (en) | Method for preparing high-purity ammonium paratungstate | |
| CN117361573B (en) | Method for directly preparing battery-grade sodium fluoride from industrial-grade sodium carbonate | |
| CN115536045B (en) | Method for efficiently and continuously preparing ultrapure lithium carbonate with uniform granularity | |
| CN118146086B (en) | Method for purifying succinic acid from fermentation broth | |
| CN112521363B (en) | Crystallization and purification device and method for ethylene carbonate | |
| CN216191107U (en) | Device for improving quality of trichlorosilane |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |