CN115536045A - Method for efficiently and continuously preparing ultrapure lithium carbonate with uniform particle size - Google Patents
Method for efficiently and continuously preparing ultrapure lithium carbonate with uniform particle size Download PDFInfo
- Publication number
- CN115536045A CN115536045A CN202211350314.5A CN202211350314A CN115536045A CN 115536045 A CN115536045 A CN 115536045A CN 202211350314 A CN202211350314 A CN 202211350314A CN 115536045 A CN115536045 A CN 115536045A
- Authority
- CN
- China
- Prior art keywords
- pyrolysis
- kettle
- lithium carbonate
- pyrolysis kettle
- particle size
- 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.)
- Granted
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
-
- 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
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
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 discloses a method for efficiently and continuously preparing ultrapure lithium carbonate with uniform particle size, belongs to the field of lithium carbonate production, and solves the problems of low purity, uneven and unstable particle size and low production efficiency of the conventional ultrapure lithium carbonate production process. The method comprises the following steps: preparing a lithium bicarbonate solution; purifying the lithium bicarbonate solution; performing continuous pyrolysis by using a continuous pyrolysis device; washing with water; and (4) calcining. The invention designs a method for continuously producing the ultrapure lithium carbonate, and the liquid in each pyrolysis kettle continuously enters and exits at the same time in the production process, thereby truly realizing the continuous production of the lithium carbonate, greatly shortening the reaction period and improving the production efficiency. In the invention, the Li concentration of the liquid in each stage of pyrolysis kettle is reduced to the same extent, so that Li in unit time 2 CO 3 The precipitation rate is the same, the crystal growth rate is also the same, the precipitation of the ultrapure lithium carbonate is reduced according to a concentration gradient mode, and the purity and the granularity of the obtained ultrapure lithium carbonate are stable and uniform.
Description
Technical Field
The invention belongs to the field of lithium carbonate production, and particularly relates to a method for efficiently and continuously preparing ultrapure lithium carbonate with uniform particle size.
Background
With the advancement of the times and the development of technology, li 2 CO 3 The lithium ion battery is widely applied to the fields of ceramics, glass, atomic energy, aerospace, lithium batteries, lithium alloys, medicines and the like, and is also a raw material for preparing various lithium compounds. Due to different applications, different requirements are imposed on the purity and particle size of lithium carbonate. 99.9 percent of high-purity lithium carbonate is used as a positive electrode material of the lithium ion battery; 99.99% of high-purity lithium carbonate is used for the electrolyte of the lithium ion battery; 99.999% of ultrapure lithium carbonate is used in medicine and surface elastic wave element materials. With the continuous expansion of the application range of lithium products in the high-tech field, the demand for lithium salt is increasing at home and abroad, the requirements for the purity of the products are higher and higher, and the requirements for the particle size are also more and more rigorous, so that the development of high-added-value ultra-pure lithium salt products with different particle sizes is imperative.
Disclosure of Invention
The invention aims to provide a method for efficiently and continuously preparing ultrapure lithium carbonate with uniform particle size, which aims to solve the problems of low purity, uneven and unstable particle size and low production efficiency of the conventional ultrapure lithium carbonate production process.
The technical scheme of the invention is as follows: a method for efficiently and continuously preparing ultrapure lithium carbonate with uniform particle size comprises the following steps:
A. preparation of lithium bicarbonate solution: injecting pure water into a carbonization reaction kettle, starting stirring, adding lithium carbonate into the carbonization reaction kettle, introducing carbon dioxide, fully reacting to prepare a lithium bicarbonate solution, and testing the content of Li in the lithium bicarbonate solution, wherein the content of Li is 7.5-8g/L, namely the qualified lithium bicarbonate solution;
B. purifying the lithium bicarbonate solution: purifying the qualified lithium bicarbonate solution prepared in the step A to obtain a purified lithium bicarbonate solution;
C. continuous pyrolysis using a continuous pyrolysis apparatus: the continuous pyrolysis device comprises a high-level storage tank and a plurality of pyrolysis kettles which are sequentially arranged from top to bottom, the high-level storage tank and each pyrolysis kettle are sequentially communicated through a pipeline, and each pipeline is provided with a control valve;
the specific operation method comprises the following steps: b, placing the purified lithium bicarbonate solution prepared in the step B into a high-level storage tank; sequentially opening each control valve from top to bottom to enable the purified lithium bicarbonate solution to flow downwards and flow into each pyrolysis kettle in sequence, closing each control valve, heating the pyrolysis kettles, starting pyrolysis reaction in each pyrolysis kettle, controlling the reaction to enable the Li content of liquid in each pyrolysis kettle to gradually decrease from top to bottom to form a gradient, then sequentially opening each control valve from top to bottom to enable the liquid in each reaction kettle to enter liquid and exit liquid while performing pyrolysis reaction, enabling the liquid in the lowermost pyrolysis kettle to exit liquid to a centrifugal machine for centrifugation, monitoring the Li content of the liquid in each pyrolysis kettle in a continuous reaction process, and controlling the opening degree of each control valve and the heating degree of each pyrolysis kettle to enable the Li content in each pyrolysis kettle to keep the gradient, so that the purified lithium bicarbonate solution in each pyrolysis kettle continuously enters and exits and keeps the pyrolysis reaction, and lithium carbonate is continuously pyrolyzed and produced;
D. washing with water: washing wet lithium carbonate centrifuged by a centrifuge with water at the temperature of more than or equal to 90 ℃, centrifuging the lithium carbonate while the lithium carbonate is hot after washing with water, and controlling the water content in the lithium carbonate after centrifuging to be less than or equal to 5%;
E. and (3) calcining: calcining for 4-6h at 400-450 ℃ to obtain the qualified dry ultrapure lithium carbonate, wherein the purity of the ultrapure lithium carbonate is more than or equal to 99.999%.
As a further improvement of the present invention, in step C, the continuous pyrolysis apparatus is provided with three pyrolysis kettles, namely, a first pyrolysis kettle, a second pyrolysis kettle and a third pyrolysis kettle, a first valve is provided between the high-level storage tank and the first pyrolysis kettle, a second valve is provided between the first pyrolysis kettle and the second pyrolysis kettle, a third valve is provided between the second pyrolysis kettle and the third pyrolysis kettle, the third pyrolysis kettle is connected to the centrifuge, and a liquid outlet valve is provided between the third pyrolysis kettle and the centrifuge.
As a further improvement of the invention, in the step A, the Li content in the qualified lithium bicarbonate solution is 8g/L; in the step C, the Li content in the first pyrolysis kettle, the second pyrolysis kettle and the third pyrolysis kettle is controlled to be 6g/L, 4g/L and 2g/L respectively.
As a further improvement of the present invention, in step B, the method of the purification treatment comprises the steps of:
s1, four-stage precise filtration: firstly, passing qualified lithium bicarbonate solution through a filter bag with the particle size of 0.5 mu m, filtering out impurities with larger particles, then passing through a filter element with the particle size of 0.05 mu m, continuously filtering out small-particle impurities, and finally continuously passing through 2 filter elements with the particle size of 0.01 mu m;
s2, ion exchange impurity removal: removing impurity ions by using ion exchange resin;
s3, secondary fine filtration: and (3) passing the lithium bicarbonate solution after ion exchange through a filter element with the diameter of 0.01 mu m for precision filtration.
In the purification treatment method, the multistage precise filtration directly influences the ion exchange effect and whether the purified qualified lithium bicarbonate solution can be obtained, if small particulate matters invisible to the naked eye cannot be filtered in the precise filtration step, the small particulate matters enter the micropore channel of the ion exchange resin to block the channel, so that the capacity of the ion exchange resin for removing impurity ions is greatly reduced. Indexes of the purified lithium bicarbonate solution are as follows: al is less than or equal to 0.0003g/L, as is less than or equal to 0.00001g/L, ca is less than or equal to 0.0001g/L, cu is less than or equal to 0.00001g/L, fe is less than or equal to 0.0001g/L, K is less than or equal to 0.0009g/L, mg is less than or equal to 0.00045g/L, mn is less than or equal to 0.000004g/L, na is less than or equal to 0.0003g/L, ni is less than or equal to 0.000005g/L, pb is less than or equal to 0.000001g/L, si is less than or equal to 0.00048g/L, zn is less than or equal to 0.000001g/L, co is less than or equal to 0.000005g/L, SO is less than or equal to 0.00001g/L 4 2- ≤0.001g/L、Cl≤0.0002g/L。
As a further improvement of the invention, in the step D, the solid-liquid mass ratio during water washing is 1.
As a further improvement of the invention, in the step C, each pyrolysis kettle is heated by steam, and the heating efficiency is high.
As a further improvement of the invention, stirring devices are respectively arranged in the first pyrolysis kettle, the second pyrolysis kettle and the third pyrolysis kettle to ensure uniform heating and uniform crystallization.
As a further improvement of the invention, the bottoms of the first pyrolysis kettle, the second pyrolysis kettle and the third pyrolysis kettle are in a conical shape. Aiming at the characteristic that the lithium carbonate is easy to scar, the conical design can weaken the scar of the lithium carbonate, and is more beneficial to continuous production.
As a further improvement of the invention, the outer walls of the first pyrolysis kettle, the second pyrolysis kettle and the third pyrolysis kettle are respectively provided with an insulating layer.
The invention has the beneficial effects that: the invention designs a method for continuously producing the ultrapure lithium carbonate, and the liquid in each pyrolysis kettle continuously enters and exits at the same time and continuously enters and exits in the production process, thereby truly realizing the continuous production of the lithium carbonate, greatly shortening the reaction period and improving the production efficiency. In the invention, the Li concentration of the liquid in each stage of pyrolysis kettle is reduced to the same extent, so that Li in unit time 2 CO 3 The precipitation rate is the same, the crystal growth rate is also the same, the precipitation of the ultrapure lithium carbonate is reduced according to a concentration gradient mode, the purity and the granularity of the obtained ultrapure lithium carbonate are stable and uniform, and the purity and the granularity of the obtained ultrapure lithium carbonate both meet the industrial standard. The method is simple, easy to operate and has good popularization value.
Drawings
FIG. 1 is a schematic view of the structure of a continuous pyrolysis apparatus in the present invention.
In the figure: 1-a first pyrolysis kettle; 11-a first valve; 2-a second pyrolysis kettle; 21-a second valve; 3-a third pyrolysis kettle; 31-a third valve; 32-a liquid outlet valve; 4-high reserve tank; 5-a centrifuge; 6-steam pipe; 7-a stirring device; 8-insulating layer.
Detailed Description
The present invention will be described in further detail with reference to specific embodiments.
In following embodiments 1-6, the continuous pyrolysis device that adopts is as shown in fig. 1, including high reserve tank 4 and the three pyrolysis cauldron that from top to bottom sets gradually, be first pyrolysis cauldron 1 respectively, second pyrolysis cauldron 2 and third pyrolysis cauldron 3, high reserve tank 4, first pyrolysis cauldron 1, second pyrolysis cauldron 2 and third pyrolysis cauldron 3 communicate in proper order, be equipped with first valve 11 between high reserve tank 4 and the first pyrolysis cauldron 1, be equipped with second valve 21 between first pyrolysis cauldron 1 and the second pyrolysis cauldron 2, be equipped with third valve 31 between second pyrolysis cauldron 2 and the third pyrolysis cauldron 3, third pyrolysis cauldron 3 connects centrifuge 5, be equipped with out liquid valve 32 between third pyrolysis cauldron 3 and the centrifuge 5. The first valve 11, the second valve 21, the third valve 31 and the liquid outlet valve 32 are all electromagnetic valves. A steam pipe 6 and a stirring device 7 are arranged in each of the first pyrolysis kettle 1, the second pyrolysis kettle 2 and the third pyrolysis kettle 3. The bottoms of the first pyrolysis kettle 1, the second pyrolysis kettle 2 and the third pyrolysis kettle 3 are in a conical shape.
Examples 1,
A method for efficiently and continuously preparing ultrapure lithium carbonate with uniform particle size comprises the following steps:
A. preparation of lithium bicarbonate solution: injecting 1000L of pure water into a 1500L carbonization reaction kettle, starting stirring, then taking 42.77kg of battery-grade lithium carbonate (with the purity of 99.5 percent) (the adding amount of the lithium carbonate is accurately added, the using amount of the lithium carbonate is calculated in advance before adding the lithium carbonate), adding a small amount of lithium carbonate into the carbonization reaction kettle for multiple times, then introducing carbon dioxide, fully reacting for 4 hours to prepare a lithium bicarbonate solution, and when the solution becomes clear and transparent, testing the content of Li in the lithium bicarbonate solution by using hydrochloric acid titration or atomic absorption, and when the content of Li is 8g/L, completing carbonization to obtain the qualified lithium bicarbonate solution. The formula of the charging calculation is as follows: lithium carbonate usage = deionized water volume lithium content/0.188/0.995 in the lithium bicarbonate solution, where the lithium carbonate usage is in kg, deionized water volume is in m ethanol, lithium content in the lithium bicarbonate solution is in kg/m ethanol, 0.188 is the mass fraction of lithium in lithium carbonate, and 0.995 is the main content of battery-grade lithium carbonate of 99.5%.
B. Purifying the lithium bicarbonate solution: and B, purifying the qualified lithium bicarbonate solution prepared in the step A, wherein the purification treatment method comprises the following steps:
four-stage precise filtration: firstly, passing a qualified lithium bicarbonate solution through a filter bag with the particle size of 0.5 mu m, filtering out impurities with larger particles, then passing through a filter element with the particle size of 0.05 mu m, continuously filtering out small-particle impurities, and finally continuously passing through 2 filter elements with the particle size of 0.01 mu m;
removing impurities by ion exchange: firstly, the Ca is removed by cation exchange resin which is mixed with a plurality of resins with strong specific ion exchange capacity and added into an ion exchange column 2+ 、Mg 2+ Removing impurity ions, and removing SO by anion exchange resin 4 2- ；
And (3) secondary fine filtration: and (3) carrying out precision filtration on the lithium bicarbonate solution after ion exchange through a filter element with the diameter of 0.01 mu m to obtain the purified lithium bicarbonate solution.
C. Continuous pyrolysis was carried out using a continuous pyrolysis apparatus: putting the purified lithium bicarbonate solution prepared in the step B into a high-level storage tank 4; opening the first valve 11, the second valve 21 and the third valve 31 from top to bottom in sequence to enable the purified lithium bicarbonate solution to flow downward and automatically and flow into the first pyrolysis kettle 1, the second pyrolysis kettle 2 and the third pyrolysis kettle 3 in sequence, wherein the liquid level in each pyrolysis kettle is about two thirds of the kettle body, and closing the first valve 11, the second valve 21 and the third valve 31; introducing high-temperature steam into the first pyrolysis kettle 1, the second pyrolysis kettle 2 and the third pyrolysis kettle 3 for heating, starting pyrolysis reaction in each pyrolysis kettle, and controlling the reaction to ensure that the Li content of liquid in the first pyrolysis kettle 1 reaches 6g/L, the Li content of liquid in the second pyrolysis kettle 2 reaches 4g/L and the Li content of liquid in the third pyrolysis kettle 3 reaches 2g/L; and then, opening the first valve 11, the second valve 21, the third valve 31 and the liquid outlet valve 32 from top to bottom in sequence, so that liquid in each reaction kettle enters the liquid and goes out of the liquid while undergoing a pyrolysis reaction, and liquid in the third pyrolysis kettle 3 goes out of the liquid and is centrifuged by a centrifuge 5. The purified lithium bicarbonate solution continuously flows from the high-level storage tank 4 to the first pyrolysis kettle 1, from the first pyrolysis kettle 1 to the second pyrolysis kettle 2, from the second pyrolysis kettle 2 to the third pyrolysis kettle 3, and from the third pyrolysis kettle 3 to the centrifuge 5, and continuously produces by continuous pyrolysis while entering and exiting, the Li content of liquid in each pyrolysis kettle is monitored in the continuous reaction process, and the Li content in each pyrolysis kettle is kept in the gradient by controlling the opening degree of the first valve 11, the second valve 21, the third valve 31 and the liquid outlet valve 32 and the heating degree of each pyrolysis kettle.
D. Washing with water: washing wet lithium carbonate centrifuged by the centrifuge 5 with water at a solid-liquid mass ratio of 1 to 5 at a temperature of not less than 90 ℃ for 30min, centrifuging while hot after washing, and controlling the water content in the lithium carbonate after centrifuging to be not more than 5%.
E. And (3) calcining: calcining for 5 hours at the temperature of 400 ℃ to obtain the qualified and dried ultrapure lithium carbonate.
Purity test results: 99.99915%. The result of the particle size test is as follows: d10:1.7 μm, D50:6 μm, D90:14 μm.
This example 5 set was repeated and the experimental data is shown in table 1.
As can be seen from Table 1, the prepared ultrapure lithium carbonate is stable in purity and granularity by carrying out continuous pyrolysis in a mode of carrying out inlet-outlet while reducing the concentration according to the gradient of 2g/L, not only meets the industry YS/T582-2013 standard, but also is very stable in purity and granularity fluctuation.
Examples 2,
The present example differs from example 1 in that: in step D, the solid-liquid mass ratio at the time of washing with water was 1. Purity test results: 99.998 percent. The result of the particle size test is as follows: d10:1.9 μm, D50:5 μm, D90:13 μm.
Examples 3,
This example differs from example 1 in that: in step D, the solid-liquid mass ratio at the time of washing was 1. Purity test results: 99.99914 percent. The result of the particle size test is as follows: d10:1.9 μm, D50:5.1 μm, D90:13 μm.
Examples 4,
The present example differs from example 1 in that: in step D, the solid-liquid mass ratio at the time of washing with water was 1. Purity test results: 99.99917%. And (3) granularity test results: d10:1.8 μm, D50:6 μm, D90:13 μm.
Examples 1 to 4 the following examples, in which the solid-liquid mass ratio of water washing was adjusted from 1. Considering that in industrial production, the washing proportion is too large, the requirement on the liquid treatment capacity of the production system is increased, and the purity requirement is met. Therefore, a solid-liquid ratio of 1.
Examples 5,
A method for efficiently and continuously preparing ultrapure lithium carbonate with uniform particle size comprises the following steps:
A. preparation of lithium bicarbonate solution: injecting 1500L of pure water into a 2000L pyrolysis reaction kettle, starting stirring, then taking 64.15kg of battery-grade lithium carbonate (with the purity of 99.5 percent) (the adding amount of the lithium carbonate is accurately added, the using amount of the used lithium carbonate is calculated in advance before adding), adding the lithium carbonate into the carbonization reaction kettle for multiple times in a small amount, then introducing carbon dioxide, and fully reacting for 4 hours to prepare the lithium bicarbonate solution. And when the solution becomes clear and transparent, testing the content of Li in the lithium bicarbonate solution by a titration method, wherein the content of Li is 8g/L, and the qualified lithium bicarbonate solution is obtained.
The other steps were the same as in example 1.
Purity test results: 99.99917%. The result of the particle size test is as follows: d10:2.4 μm, D50:7 μm, D90:14 μm.
Examples 6,
This example differs from example 5 in that: in step E, the calcination temperature was 450 ℃ and the other steps were the same as in example 1. In examples 5 and 6, the calcination temperature was increased from 400 ℃ to 450 ℃, the purity of ultrapure lithium carbonate was not greatly changed, and 400 ℃ was preferably selected as the drying temperature in view of energy saving and production cost.
Purity test results: 99.99914 percent. The result of the particle size test is as follows: d10:2.3 μm, D50:7.2 μm, D90:14 μm.
Examples 7,
The continuous pyrolysis device that this embodiment adopted is equipped with two pyrolysis kettles, and centrifuge is connected to last pyrolysis kettle.
The operation procedure in step C of this example was similar to that in step C of example 1, except that the Li content of the liquid in the first pyrolysis tank was maintained at 5g/L and the Li content of the liquid in the second pyrolysis tank was maintained at 2g/L during the reaction. The other steps were the same as in example 1.
Purity test results: 99.9986 percent. The result of the particle size test is as follows: d10:4 μm, D50:13 μm, D90:21 μm.
Examples 8,
The continuous pyrolysis device that this embodiment adopted is equipped with six pyrolysis cauldron, and last pyrolysis cauldron is connected centrifuge.
The operation procedure in step C of this example is similar to that in step C of example 1, except that during the reaction, the Li content of the liquid in the first pyrolysis kettle is maintained at 7g/L, the Li content of the liquid in the second pyrolysis kettle is maintained at 6g/L, the Li content of the liquid in the third pyrolysis kettle is maintained at 5g/L, the Li content of the liquid in the fourth pyrolysis kettle is maintained at 4g/L, the Li content of the liquid in the fifth pyrolysis kettle is maintained at 3g/L, and the Li content of the liquid in the sixth pyrolysis kettle is maintained at 2g/L. The other steps were the same as in example 1.
Purity test results: 99.99911%. The result of the particle size test is as follows: d10:2 μm, D50:4.4 μm, D90:11.5 μm.
When the continuous step pyrolysis is carried out in the embodiment 1, the Li content in the solution is reduced by 2g/L, the Li content in the solution in the embodiment 7 is reduced by 3g/L, and the Li content in the solution in the embodiment 8 is reduced by 1 g/L. The purity and particle size data for examples 1, 7 and 8 are shown in table 2.
As can be seen from Table 2, during continuous step pyrolysis, the Li content in the solution is reduced according to 3g/L, the purity of the prepared lithium carbonate is less than 99.999%, and the granularity index does not meet the YS/T582-2013 standard. The Li content is reduced according to 1g/L and 2g/L, the purity of the prepared lithium carbonate is over 99.999 percent, and the granularity also meets YS/T582-2013 standard, the two modes can be used for producing the ultrapure lithium carbonate, but the process route for preparing the ultrapure lithium carbonate according to 1g/L reduction is longer, a plurality of pyrolysis kettles are used, the height of a workshop is required when the lithium carbonate is used for self-flowing, and the preparation of the ultrapure lithium carbonate according to 2g/L reduction is comprehensively considered to be better.
Comparative examples 1,
The comparative example differs from example 1 in that: in the step C, a single-kettle intermittent pyrolysis method rather than a continuous process is adopted, 1000L of the purified lithium bicarbonate solution prepared in the step B is injected into a 1200L pyrolysis kettle, stirring is started, heating is started, the temperature is raised to be higher than 90 ℃ after the temperature is raised to be higher than 90 ℃, heat preservation is carried out for 30min, and after pyrolysis is finished, lithium carbonate slurry is discharged from a bottom valve of the pyrolysis kettle to a centrifugal machine for centrifugation. The other steps were the same as in example 1.
This comparative example was repeated 5 times and the experimental data are shown in table 3.
As can be seen from Table 3, in comparison between the continuous gradient pyrolysis and the non-continuous single-kettle pyrolysis, the particle size and purity of the ultrapure lithium carbonate obtained by the continuous gradient pyrolysis both meet the YS/T582-2013 standard, and are very stable. And the impurities of the ultrapure lithium carbonate obtained by the non-continuous single-kettle pyrolysis are seriously wrapped, the chemical index does not reach 99.999 percent, and in addition, the granularity of the ultrapure lithium carbonate prepared each time greatly fluctuates and does not meet the YS/T582-2013 standard. The preparation of the ultrapure lithium carbonate by continuous gradient concentration control is more controllable and stable in the aspects of purity and granularity, and the chemical index and the physical index of the product both accord with the industrial standard and the requirement of the market on stability.
Claims (9)
1. A method for efficiently and continuously preparing ultrapure lithium carbonate with uniform particle size is characterized by comprising the following steps:
A. preparation of lithium bicarbonate solution: injecting pure water into a carbonization reaction kettle, starting stirring, adding lithium carbonate into the carbonization reaction kettle, introducing carbon dioxide, fully reacting to prepare a lithium bicarbonate solution, and testing the content of Li in the lithium bicarbonate solution, wherein the content of Li is 7.5-8g/L, namely the qualified lithium bicarbonate solution;
B. purifying the lithium bicarbonate solution: purifying the qualified lithium bicarbonate solution prepared in the step A to obtain a purified lithium bicarbonate solution;
C. continuous pyrolysis using a continuous pyrolysis apparatus: the continuous pyrolysis device comprises a high-position reserve tank (4) and a plurality of pyrolysis kettles which are sequentially arranged from top to bottom, the high-position reserve tank (4) and each pyrolysis kettle are sequentially communicated through a pipeline, and each pipeline is provided with a control valve;
the specific operation method comprises the following steps: putting the purified lithium bicarbonate solution prepared in the step B into a high-level storage tank (4); sequentially opening each control valve from top to bottom to enable the purified lithium bicarbonate solution to flow downwards and flow into each pyrolysis kettle in sequence, closing each control valve, heating the pyrolysis kettles, starting pyrolysis reaction in each pyrolysis kettle, controlling the reaction to enable the Li content of liquid in each pyrolysis kettle to gradually decrease from top to bottom to form a gradient, then sequentially opening each control valve from top to bottom to enable the liquid in each reaction kettle to enter liquid and exit liquid while performing pyrolysis reaction, enabling the liquid in the lowermost pyrolysis kettle to exit liquid to a centrifugal machine (5) for centrifugation, monitoring the Li content of the liquid in each pyrolysis kettle in a continuous reaction process, and controlling the opening degree of each control valve and the heating degree of each pyrolysis kettle to enable the Li content in each pyrolysis kettle to keep the gradient, so that the purified lithium bicarbonate solution in each pyrolysis kettle continuously enters and exits and keeps the pyrolysis reaction, and lithium carbonate is continuously pyrolyzed and produced;
D. washing with water: washing wet lithium carbonate centrifuged by the centrifuge (5) with water, wherein the washing temperature is more than or equal to 90 ℃, centrifuging the lithium carbonate while the lithium carbonate is hot after washing with water, and controlling the water content in the lithium carbonate after centrifuging to be less than or equal to 5%;
E. and (3) calcining: calcining for 4-6h at 400-450 ℃ to obtain the qualified dry ultrapure lithium carbonate, wherein the purity of the ultrapure lithium carbonate is more than or equal to 99.999%.
2. The method for efficiently and continuously preparing ultrapure lithium carbonate with uniform particle size according to claim 1, wherein: in step C, the continuous pyrolysis device is provided with three pyrolysis kettles, namely a first pyrolysis kettle (1), a second pyrolysis kettle (2) and a third pyrolysis kettle (3), a first valve (11) is arranged between the high-level stock tank (4) and the first pyrolysis kettle (1), a second valve (21) is arranged between the first pyrolysis kettle (1) and the second pyrolysis kettle (2), a third valve (31) is arranged between the second pyrolysis kettle (2) and the third pyrolysis kettle (3), the third pyrolysis kettle (3) is connected with a centrifugal machine (5), and a liquid outlet valve (32) is arranged between the third pyrolysis kettle (3) and the centrifugal machine (5).
3. The method for efficiently and continuously preparing the ultrapure lithium carbonate with uniform particle size according to claim 2, wherein the method comprises the following steps: in the step A, the Li content in the qualified lithium bicarbonate solution is 8g/L; in the step C, the Li content in the first pyrolysis kettle (1), the second pyrolysis kettle (2) and the third pyrolysis kettle (3) is controlled to be 6g/L, 4g/L and 2g/L respectively.
4. A method for the efficient continuous preparation of ultrapure lithium carbonate of uniform particle size according to any one of claims 1 to 3 wherein: in step B, the method of decontamination treatment comprises the steps of:
s1, four-stage precise filtration: firstly, passing qualified lithium bicarbonate solution through a filter bag with the particle size of 0.5 mu m, filtering out impurities with larger particles, then passing through a filter element with the particle size of 0.05 mu m, continuously filtering out small-particle impurities, and finally continuously passing through 2 filter elements with the particle size of 0.01 mu m;
s2, ion exchange impurity removal: removing impurity ions by using ion exchange resin;
s3, secondary fine filtration: and (3) passing the lithium bicarbonate solution after ion exchange through a filter element with the diameter of 0.01 mu m for precision filtration.
5. The method for efficiently and continuously preparing the ultrapure lithium carbonate with uniform particle size according to claim 4, wherein the method comprises the following steps: in the step D, the solid-liquid mass ratio in water washing is 1.
6. The method for efficiently and continuously preparing the ultrapure lithium carbonate with uniform particle size according to claim 5, wherein the method comprises the following steps: in step C, each pyrolysis kettle is heated with steam.
7. The method for efficiently and continuously preparing the ultrapure lithium carbonate with uniform particle size according to claim 2, wherein the method comprises the following steps: stirring devices (7) are respectively arranged in the first pyrolysis kettle (1), the second pyrolysis kettle (2) and the third pyrolysis kettle (3).
8. The method for efficiently and continuously preparing ultrapure lithium carbonate with uniform particle size according to claim 1 or 7, wherein: the bottoms of the first pyrolysis kettle (1), the second pyrolysis kettle (2) and the third pyrolysis kettle (3) are conical.
9. The method for efficiently and continuously preparing the ultrapure lithium carbonate with uniform particle size according to claim 8, wherein the method comprises the following steps: the outer walls of the first pyrolysis kettle (1), the second pyrolysis kettle (2) and the third pyrolysis kettle (3) are respectively provided with a heat preservation layer (8).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211350314.5A CN115536045B (en) | 2022-11-01 | 2022-11-01 | Method for efficiently and continuously preparing ultrapure lithium carbonate with uniform granularity |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211350314.5A CN115536045B (en) | 2022-11-01 | 2022-11-01 | Method for efficiently and continuously preparing ultrapure lithium carbonate with uniform granularity |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115536045A true CN115536045A (en) | 2022-12-30 |
| CN115536045B CN115536045B (en) | 2023-04-25 |
Family
ID=84718039
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211350314.5A Active CN115536045B (en) | 2022-11-01 | 2022-11-01 | Method for efficiently and continuously preparing ultrapure lithium carbonate with uniform granularity |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115536045B (en) |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012147555A1 (en) * | 2011-04-26 | 2012-11-01 | Ｄｏｗａエコシステム株式会社 | Lithium carbonate production method and lithium carbonate production device |
| CN103833053A (en) * | 2014-01-21 | 2014-06-04 | 四川天齐锂业股份有限公司 | Method of preparing high-purity lithium carbonate of the 5 N grade |
| RU2013140016A (en) * | 2013-08-28 | 2015-03-10 | Закрытое акционерное общество (ЗАО) "Экостар-Наутех" | METHOD FOR PRODUCING LITHIUM CARBONATE FROM TECHNICAL LITHIUM CARBONATE AND INSTALLATION FOR ITS IMPLEMENTATION |
| CN106745100A (en) * | 2016-12-23 | 2017-05-31 | 荆门市格林美新材料有限公司 | The preparation system and preparation method of battery-level lithium carbonate |
| CN108217699A (en) * | 2018-02-08 | 2018-06-29 | 江苏九九久科技有限公司 | A kind of method that pure Lithium Carbonate is prepared using industrial level lithium carbonate |
| WO2019160982A1 (en) * | 2018-02-17 | 2019-08-22 | Lilac Solutions, Inc. | Integrated system for lithium extraction and conversion |
| WO2022051598A2 (en) * | 2020-09-03 | 2022-03-10 | Cornell University | Methods and systems for producing solid inorganic carbonate and bicarbonate compounds |
| 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 |
-
2022
- 2022-11-01 CN CN202211350314.5A patent/CN115536045B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012147555A1 (en) * | 2011-04-26 | 2012-11-01 | Ｄｏｗａエコシステム株式会社 | Lithium carbonate production method and lithium carbonate production device |
| RU2013140016A (en) * | 2013-08-28 | 2015-03-10 | Закрытое акционерное общество (ЗАО) "Экостар-Наутех" | METHOD FOR PRODUCING LITHIUM CARBONATE FROM TECHNICAL LITHIUM CARBONATE AND INSTALLATION FOR ITS IMPLEMENTATION |
| CN103833053A (en) * | 2014-01-21 | 2014-06-04 | 四川天齐锂业股份有限公司 | Method of preparing high-purity lithium carbonate of the 5 N grade |
| CN106745100A (en) * | 2016-12-23 | 2017-05-31 | 荆门市格林美新材料有限公司 | The preparation system and preparation method of battery-level lithium carbonate |
| CN108217699A (en) * | 2018-02-08 | 2018-06-29 | 江苏九九久科技有限公司 | A kind of method that pure Lithium Carbonate is prepared using industrial level lithium carbonate |
| WO2019160982A1 (en) * | 2018-02-17 | 2019-08-22 | Lilac Solutions, Inc. | Integrated system for lithium extraction and conversion |
| WO2022051598A2 (en) * | 2020-09-03 | 2022-03-10 | Cornell University | Methods and systems for producing solid inorganic carbonate and bicarbonate compounds |
| 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 |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115536045B (en) | 2023-04-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR102190786B1 (en) | Method and system for producing battery grade and high purity grade lithium hydroxide and lithium carbonate from a high-impure lithium source | |
| CA2985579C (en) | Method of producing lithium carbonate from lithium chloride with gas-liquid-solid separator | |
| CN103318925B (en) | Method for producing high-purity lithium carbonate by using lithium concentrate | |
| CN102659144B (en) | Method for preparing high purity level lithium hydroxide monohydrate | |
| CN114477245A (en) | Method for preparing lithium carbonate of battery by continuously carbonizing industrial-grade lithium carbonate | |
| CN106957124A (en) | A kind of tertiary cathode material produces the processing method and processing system of waste water | |
| CN102030348B (en) | Device and method for continuously preparing magnesium hydroxide flame retardant | |
| CN112538575A (en) | Method for extracting lithium from salt lake | |
| EP4230278A1 (en) | Method for recovering lithium from lithium precipitation mother liquor | |
| CN111892071B (en) | Method for purifying lithium carbonate | |
| CN113929148B (en) | Preparation method of superfine high-purity ammonium rhenate for rhenium powder reduction | |
| CN111960446B (en) | Method for continuously producing high-purity lithium carbonate | |
| JP2014005191A (en) | Methods for preparing and controlling particle size of low-bet trimanganese tetroxide, and trimanganese tetroxide | |
| CN108840354B (en) | Deep impurity removal method for battery-grade lithium chloride | |
| CN108529666B (en) | Method for preparing lithium titanate from inorganic titanium source, product and application | |
| CN115536045B (en) | Method for efficiently and continuously preparing ultrapure lithium carbonate with uniform granularity | |
| CN112694112B (en) | Method for continuously preparing pseudo-boehmite | |
| CN105197966A (en) | Purification method of ultrahigh-activity lithium fluoride | |
| CN111392704A (en) | Preparation method of optical-grade aluminum metaphosphate | |
| CN107473242B (en) | A method of high-purity lithium oxide is prepared using lithium carbonate | |
| CN115893454B (en) | Method for efficiently producing ultrapure lithium carbonate with uniform and stable granularity | |
| CN211920886U (en) | Device for preparing battery-grade lithium carbonate by using membrane separation technology | |
| CN218530922U (en) | Continuous pyrolysis device for preparing ultrapure lithium carbonate | |
| CN111268702A (en) | Method and device for preparing battery-grade lithium carbonate by using membrane separation technology | |
| CN206751588U (en) | A kind of processing system of tertiary cathode material production waste water |
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 |