阅读说明：本技术 一种低磁性球形高纯碳酸锂制备方法 (Preparation method of low-magnetism spherical high-purity lithium carbonate ) 是由 郭燕平 郭幸 崔永福 敬军臣 宋如梦 胡腊梅 王国超 于 2021-08-25 设计创作，主要内容包括：一种低磁性球形高纯碳酸锂制备方法,包括以下步骤：碳酸氢化、管道除铁器除磁性异物、树脂净化除杂、除硅、喷雾干燥造粒、除铁器除磁性物质、获得低磁性球形高纯碳酸锂。本发明工艺简单,产品优良,操作过程稳定,生产周期短,设备投资较小,制备的碳酸锂纯度高,磁性物质含量少,锂的综合回收率达到99.2%,生产成本低,适于产业化生产。(A preparation method of low-magnetism spherical high-purity lithium carbonate comprises the following steps: the method comprises the steps of hydrogenation of carbonic acid, magnetic foreign matter removal by a pipeline iron remover, resin purification and impurity removal, silicon removal, spray drying granulation, magnetic substance removal by the iron remover and low-magnetism spherical high-purity lithium carbonate obtaining. The method has the advantages of simple process, excellent product, stable operation process, short production period, less equipment investment, high purity of the prepared lithium carbonate, low content of magnetic substances, comprehensive recovery rate of lithium reaching 99.2 percent, low production cost and suitability for industrial production.)

1. A preparation method of low-magnetism spherical high-purity lithium carbonate is characterized by comprising the following steps:

a. putting lithium carbonate crude salt prepared from salt lake lithium salt as a raw material into a container, adding deionized water, and introducing high-purity CO₂Stirring;

b. b, pumping the solution obtained after the hydrogenation of the lithium salt in the salt lake prepared in the step a into a magnetic substance removing device for removing magnetic substances;

c. b, performing ion exchange on the solution obtained in the step b through resin, wherein the content of high-valence metal ions is lower than the high-purity standard after the solution passes through the column;

d. c, adding a certain amount of silicon adsorbent into the solution obtained in the step c to remove silicon;

e. d, converting the solution obtained in the step d into spherical lithium carbonate particles by a spray drying method;

f. d, adding the dried particles obtained in the step e into a magnetic foreign matter removing device to remove deep magnetic substances;

g. obtaining the low-magnetism spherical high-purity lithium carbonate.

2. The preparation method of low-magnetism spherical high-purity lithium carbonate according to claim 1, characterized by comprising the following steps: in the step a, the mass ratio of liquid to solid is 18-24: 1, the reaction temperature is 20-35 ℃, the hydrogenation reaction time is 2-5 h, and CO is₂Flow rate of 0.5-1L/min, CO₂The gas pipeline extends into the bottom of the reactor along the wall of the reactor, holes are formed in the bottom at intervals around the disk, and the stirring speed is 200-450 rpm.

3. The preparation method of low-magnetism spherical high-purity lithium carbonate according to claim 1, characterized by comprising the following steps: and in the step b, pumping the solution into a pipeline iron remover by a magnetic pump at the speed of 0.6-10L/min to remove magnetic substances.

4. The preparation method of low-magnetism spherical high-purity lithium carbonate according to claim 1, characterized by comprising the following steps: and c, enabling the solution to pass through an ion exchange column at a speed of 2-4 BV/h, wherein the solution firstly passes through the ion exchange column filled with D403 resin, and then passes through IRC748 ion exchange resin to remove high-valence metal ions.

5. The preparation method of low-magnetism spherical high-purity lithium carbonate according to claim 1, characterized by comprising the following steps: adding 0.5-10 g/L of silicon adsorbent Fe (OH) into the solution in the step d₃Colloid, Al (OH)₃、Al₂O₃·3H₂O、FeCl₃、NaAlO₂And one or more of CaO and desilicification.

6. The preparation method of low-magnetism spherical high-purity lithium carbonate according to claim 1, characterized by comprising the following steps: and e, pumping the solution in the step e into a spray dryer by a peristaltic pump at the speed of 0.7-2L/min, wherein the inlet temperature of the drying equipment is 120-380 ℃, the outlet temperature of the drying equipment is 80-105 ℃, the rotating speed of a centrifugal disc is 20000r/min, and the atomization mode is centrifugal atomization, gas atomization or ultrasonic atomization.

7. The preparation method of low-magnetism spherical high-purity lithium carbonate according to claim 1, which is characterized by comprising the following steps: and f, adding the spherical high-purity lithium carbonate produced in the step f into an iron remover through a vibration feeder to deeply remove magnetic substances, wherein the vibration frequency of the vibration feeder is 2-10 HZ.

Technical Field

The invention belongs to the technical field of lithium carbonate preparation, and particularly relates to a preparation method of low-magnetism spherical high-purity lithium carbonate.

Background

Lithium carbonate is a main raw material of a positive electrode material (lithium nickel cobalt manganese oxide, lithium cobaltate, lithium iron phosphate, and the like) of a lithium ion battery, and in recent years, with the increasing prominence of energy problems, the development of the lithium ion battery, especially a power type lithium ion battery, has been advanced. The industrialization process of the new energy automobile including the energy storage battery is gradually increased until the new energy automobile is gushed, the starting of the terminal requirement drives the stock accumulation on the whole industrial chain to greatly improve the total demand, the low-end industrial-grade lithium carbonate is slightly excessive, the high-end battery-grade lithium carbonate is slightly tense, and the higher-end lithium carbonate is in a shortage state. Due to different purposes, different requirements are also imposed on the purity, morphology and particle size of the lithium carbonate. 3N high-purity lithium carbonate is used as a positive electrode material of a lithium ion battery, 4N high-purity lithium carbonate is used as an electrolyte of the lithium ion battery, and 5N high-purity lithium carbonate is an important raw material for preparing lithium niobate (LiNbO 3) and lithium tantalate (LiTaO 3) single crystals for surface acoustic wave devices.

With the gradual recovery of economy, the new energy field is a main increment source for pulling the demand of lithium carbonate in the future, particularly the rising of the power electric automobile industry, the power battery can be rapidly increased in the fields of automobiles, energy storage and the like, the requirement of the power battery on materials can be higher and higher, the existence of magnetic foreign matters brings great hidden dangers to the safety performance of the lithium battery, and the product quality of the lithium battery material, particularly the control of the magnetic foreign matters, is the key for solving the safety problem of the lithium battery. Therefore, the type and total content of the magnetic foreign matters in the lithium ion battery material must be strictly controlled in the production process, and the level of the content of the magnetic foreign matters is an important standard for measuring the quality of the lithium ion battery cathode material. It is therefore of great importance to prevent the introduction of metallic foreign matter from the source. The production process of the cathode material is more, and each link in the manufacturing process has the risk of introducing metal foreign matters. Since the raw material is a direct source of the metal foreign matter in the positive electrode material, thereby reducing the metal foreign matter content of the raw material, the preparation of low-magnetic high-purity battery material is the subject of current research and is also needed by the future market.

In the traditional process of carbonIn the thermal decomposition of lithium hydrogen acid, the thermal decomposition reaction is carried out in a heated reaction vessel, Li₂CO₃The particles are seriously aggregated, the granularity is large, the phenomenon of sticking the wall of the crystal is very serious, the heat conduction and the production efficiency are low, the energy consumption and the cleaning and maintenance cost are high, and the product can meet the requirements of industries such as a lithium ion battery and the like on lithium carbonate products only by crushing. Meanwhile, silicon in the product is difficult to remove, so that the taste of the lithium carbonate product is greatly reduced.

Disclosure of Invention

The invention aims to overcome the problems in the prior art and provide a preparation method of low-magnetism spherical high-purity lithium carbonate.

The invention relates to a preparation method of low-magnetism spherical high-purity lithium carbonate, which comprises the following steps:

a. putting lithium carbonate crude salt prepared from salt lake lithium salt as a raw material into a container, adding deionized water, and introducing high-purity CO₂Stirring;

b. b, pumping the solution obtained after the hydrogenation of the lithium salt in the salt lake prepared in the step a into a magnetic substance removing device for removing magnetic substances;

c. b, performing ion exchange on the solution obtained in the step b through resin, wherein the content of high-valence metal ions is lower than the high-purity standard after the solution passes through the column;

d. c, adding a certain amount of silicon adsorbent into the solution obtained in the step c to remove silicon;

e. d, converting the solution obtained in the step d into spherical lithium carbonate particles by a spray drying method;

f. d, adding the dried particles obtained in the step e into a magnetic foreign matter removing device to remove deep magnetic substances;

g. obtaining the low-magnetism spherical high-purity lithium carbonate.

In the step a, the mass ratio of liquid to solid is 18-24: 1, the reaction temperature is 20-35 ℃, the hydrogenation reaction time is 2-5 h, and CO₂Flow rate of 0.5-1L/min, CO₂The gas pipeline extends into the bottom of the reactor along the wall of the reactor, holes are formed in the bottom at intervals around the disk, and the stirring speed is 200-450 rpm.

And in the step b, pumping the solution into a pipeline iron remover by a magnetic pump at the speed of 0.6-10L/min to remove magnetic substances.

And c, enabling the solution to pass through an ion exchange column at a speed of 2-4 BV/h, enabling the solution to pass through the ion exchange column filled with D403 resin, then filling IRC748 ion exchange resin to remove high-valence metal ions, and using 10% LiOH solution to carry out structuring in the resin reconstruction process in the ion exchange column to reduce the introduction of impurity elements and improve the lithium content of the impurity-removed solution.

Adding 0.5-10 g/L of silicon adsorbent Fe (OH) into the solution in the step d₃Colloid, Al (OH)₃、Al₂O₃·3H₂O、FeCl₃、NaAlO₂And one or more of CaO and desilicification.

And e, pumping the solution in the step e into a spray dryer by a peristaltic pump at the speed of 0.7-2L/min, wherein the inlet temperature of the drying equipment is 120-380 ℃, the outlet temperature of the drying equipment is 80-105 ℃, the rotating speed of a centrifugal disc is 20000r/min, and the atomization mode is centrifugal atomization, gas atomization or ultrasonic atomization.

And f, adding the spherical high-purity lithium carbonate produced in the step f into an iron remover through a vibration feeder to deeply remove magnetic substances, wherein the vibration frequency of the vibration feeder is 2-10 HZ.

The method is characterized in that: CO in a carbonation hydrogenation process₂The gas pipeline extends into the bottom of the reactor along the wall of the reactor, and holes are formed at intervals around the bottom of the reactor, so that the lithium carbonate can be in full contact with CO₂Gas, reaction time is shortened, and reaction efficiency is improved; firstly, removing magnetic foreign matters from a lithium bicarbonate solution by using a pipeline iron remover, finally deeply removing the magnetic foreign matters from powder particles by using the iron remover, and reducing the content of the magnetic foreign matters by removing magnetic substances twice to improve the purity of lithium carbonate; in the resin impurity removal process, a lithium bicarbonate solution firstly passes through an ion exchange column filled with D403 resin to remove borate, and then passes through an IRC748 ion exchange resin to remove high-valence metal ions, and in the resin reconstruction process in the ion exchange column, 10% LiOH solution is used for reconstruction to reduce the introduction of impurity elements and improve the lithium content of the impurity removal solution; the spray drying method is utilized to prepare the lithium bicarbonate solution into the spherical high-purity lithium carbonate, thereby not only omitting the processes of heating crystallization, filtration, washing and crushing, but also preparing the lithium bicarbonate solutionThe spherical high-purity lithium carbonate with uniform particle size distribution, smooth surface, good fluidity and compactness is prepared, and the particle size can be adjusted by adjusting the atomization mode and the rotation speed of an atomization disc; the process is combined with the property that a silicon adsorbent is used for adsorbing silicate in the lithium bicarbonate solution to further improve the purity of the lithium carbonate.

Compared with the prior art, the invention has the following advantages: the method has the advantages of simple process, excellent product, stable operation process, short production period, less equipment investment, high purity of the prepared lithium carbonate, low content of magnetic substances, comprehensive recovery rate of lithium reaching 99.2 percent, low production cost and suitability for industrial production.

Drawings

FIG. 1 is a flow chart of a process employing the present invention.

Detailed Description

The following will clearly and completely describe the technical solutions in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The preparation method of the low-magnetism spherical high-purity lithium carbonate shown in the figure 1 comprises the following steps:

a. putting lithium carbonate crude salt prepared from salt lake lithium salt as a raw material into a container, adding deionized water, and introducing high-purity CO₂Stirring;

b. b, pumping the solution obtained after the hydrogenation of the lithium salt in the salt lake prepared in the step a into a magnetic substance removing device for removing magnetic substances;

c. b, performing ion exchange on the solution obtained in the step b through resin, wherein the content of high-valence metal ions is lower than the high-purity standard after the solution passes through the column;

d. adding 0.5-10 g/L of silicon adsorbent Fe (OH) into the solution obtained in the step c₃Colloid, Al (OH)₃、Al₂O₃·3H₂O、FeCl₃、NaAlO₂Removing silicon from one or more of CaO;

e. d, converting the solution obtained in the step d into spherical lithium carbonate particles by a spray drying method;

f. d, adding the dried particles obtained in the step e into a magnetic foreign matter removing device to remove deep magnetic substances;

g. obtaining the low-magnetism spherical high-purity lithium carbonate.

In the step a, the mass ratio of liquid to solid is 18-24: 1, the reaction temperature is 20-35 ℃, the hydrogenation reaction time is 2-5 h, and CO₂Flow rate of 0.5-1L/min, CO₂The gas pipeline extends into the bottom of the reactor along the wall of the reactor, holes are formed in the bottom at intervals around the disk, and the stirring speed is 200-450 rpm.

And b, pumping the solution into a pipeline iron remover by a magnetic pump at the speed of 0.6-10L/min to remove magnetic substances.

And c, enabling the solution to pass through an ion exchange column at a speed of 2-4 BV/h, enabling the solution to pass through the ion exchange column filled with D403 resin, then filling IRC748 ion exchange resin to remove high-valence metal ions, and carrying out the reconstruction by using 10% LiOH solution in the resin reconstruction process in the ion exchange column to reduce the introduction of impurity elements and improve the lithium content of the impurity-removed solution.

Adding 0.5-10 g/L of silicon adsorbent Fe (OH) into the solution in the step d₃Colloid, Al (OH)₃、Al₂O₃·3H₂O、FeCl₃、NaAlO₂And one or more of CaO and desilicification.

And e, pumping the solution into a spray dryer by a peristaltic pump at the speed of 0.7-2L/min, wherein the inlet temperature of the drying equipment is 120-380 ℃, the outlet temperature of the drying equipment is 80-105 ℃, the rotating speed of a centrifugal disc is 20000r/min, and the atomization mode is centrifugal atomization or gas atomization or ultrasonic atomization.

And f, adding the spherical high-purity lithium carbonate produced in the step f into an iron remover through a vibration feeder to deeply remove magnetic substances, wherein the vibration frequency of the vibration feeder is 2-10 HZ.

Example one

A preparation method of low-magnetism spherical high-purity lithium carbonate comprises the following steps:

a. and (3) carbonic acid hydrogenation: taking lithium carbonate crude salt prepared from salt lake lithium salt as raw material, putting into a container, adding into the container, and removingStirring the mixture with water, wherein the liquid-solid ratio is 18:1, the reaction temperature is 25 ℃, the hydrogenation reaction time is 2h, and CO₂The flow rate is 0.5L/min, and the stirring speed of the reaction kettle is 200 rpm.

b. Removing magnetic foreign matters by the pipeline iron remover: and (c) pumping the solution in the step (a) into a pipeline iron remover by a magnetic pump at the speed of 0.6L/min to remove magnetic substances.

c. Purifying and decontaminating resin: and c, carrying out ion exchange on the solution obtained in the step b by resin, wherein the speed of the solution passing through an ion exchange column is 2BV/h, removing impurities by passing through the ion exchange column filled with D403 resin, and removing high-valence metal ions by passing through IRC748 ion exchange resin.

d. Silicon removal: adding the solution obtained in the step c into Al (OH)₃Silicon is removed by the silicon adsorbent, and the adding amount of the silicon adsorbent is 2 g/L.

e. Spray drying and granulating: and d, pumping the solution obtained in the step d into a spray dryer at a speed of 1L/min by a peristaltic press, wherein the inlet temperature of the drying equipment is 160 ℃, the outlet temperature of the drying equipment is 90 ℃, and the rotating speed of a centrifugal disc is 15000 r/min.

f. Removing magnetic substances by the iron remover: and e, adding the dried particles obtained in the step e into an iron remover through a vibrating feeder to deeply remove magnetic substances, wherein the vibration frequency of the vibrating feeder is 2 HZ.

g. The product is as follows: obtaining the low-magnetism spherical high-purity lithium carbonate.

Example two

A preparation method of low-magnetism spherical high-purity lithium carbonate comprises the following steps:

a. and (3) carbonic acid hydrogenation: putting lithium carbonate crude salt prepared from salt lake lithium salt as a raw material into a container, adding deionized water, stirring, wherein the liquid-solid ratio is 24:1, the reaction temperature is 35 ℃, the hydrogenation reaction time is 5h, and CO is₂The flow rate is 1L/min, and the stirring speed of the reaction kettle is 450 rpm.

b. Removing magnetic foreign matters by the pipeline iron remover: and (c) pumping the solution in the step (a) into a pipeline iron remover by a magnetic pump at the speed of 1L/min to remove magnetic substances.

c. Purifying and decontaminating resin: and c, performing ion exchange on the solution obtained in the step b by resin, wherein the speed of the solution passing through an ion exchange column is 3BV/h, removing impurities by passing through the ion exchange column filled with D403 resin, and removing high-valence metal ions by passing through the ion exchange column filled with IRC 748.

d. Silicon removal: adding the solution obtained in the step c into a silicon adsorbent Fe (OH)₃The colloid is used for removing silicon, and the adding amount of the silicon adsorbent is 8 g/L.

e. Spray drying and granulating: and d, pumping the solution obtained in the step d into a spray dryer at a speed of 1.2L/min through a peristaltic pump, wherein the inlet temperature of the drying equipment is 220 ℃, the outlet temperature of the drying equipment is 110 ℃, and the rotating speed of a centrifugal disc is 20000 r/min.

f. Removing magnetic substances by the iron remover: and e, adding the dried particles obtained in the step e into an iron remover through a vibrating feeder to deeply remove magnetic substances, wherein the vibration frequency of the vibrating feeder is 4 HZ.

g. The product is as follows: obtaining the low-magnetism spherical high-purity lithium carbonate.

The above description is only for the preferred embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art can substitute or change the technical solution of the present invention and the inventive concept thereof within the scope of the present invention.