阅读说明：本技术 一种无水氯化锂连续结晶方法 (Anhydrous lithium chloride continuous crystallization method ) 是由 周卫强 储鹏 史先乔 曹沛栋 谢云良 董涛 戴玉明 程力伟 于 2020-12-02 设计创作，主要内容包括：本发明涉及一种无水氯化锂连续结晶方法,它包括(1)采用磁力搅拌结晶器连续投料、连续结晶,不间断排出结晶颗粒和水溶液的混合物进入连续离心机,离心得到的湿料直接进入干燥器脱去表面水；(2)稀液与离心母液从稀液入口按流速比例,与磁力搅拌结晶器上层液一起连续进入加热器,通过循环泵使加热器管程保持设定流速；(3)将加热后的氯化锂水泵入磁力搅拌结晶器下端的导流筒底部。本发明步骤简单,自动化,可长时间稳定生产。(The invention relates to a method for continuously crystallizing anhydrous lithium chloride, which comprises the steps of (1) continuously feeding and continuously crystallizing by adopting a magnetic stirring crystallizer, continuously discharging a mixture of crystal particles and an aqueous solution to enter a continuous centrifuge, and directly feeding a wet material obtained by centrifuging into a dryer to remove surface water; (2) the dilute solution and the centrifugal mother solution continuously enter a heater together with the upper layer solution of the magnetic stirring crystallizer from a dilute solution inlet according to the flow rate proportion, and the tube pass of the heater is kept at a set flow rate by a circulating pump; (3) pumping the heated lithium chloride water into the bottom of the guide shell at the lower end of the magnetic stirring crystallizer. The method has simple steps and automation, and can realize stable production for a long time.)

1. A method for continuously crystallizing anhydrous lithium chloride is characterized in that: which comprises the following steps of,

(1) continuously feeding and continuously crystallizing by adopting a magnetic stirring crystallizer, continuously discharging a mixture of crystal particles and an aqueous solution, feeding the mixture into a continuous centrifuge, and directly feeding a wet material obtained by centrifuging into a dryer to remove surface water;

(2) the dilute solution and the centrifugal mother solution continuously enter a heater together with the upper layer solution of the magnetic stirring crystallizer from a dilute solution inlet according to the flow rate proportion, and the tube pass of the heater is kept at a set flow rate by a circulating pump;

(3) pumping the heated lithium chloride water into the bottom of the guide shell at the lower end of the magnetic stirring crystallizer.

2. The method for the continuous crystallization of anhydrous lithium chloride according to claim 1, characterized in that: the magnetic stirring crystallizer comprises a crystallizer body, a motor (1) is arranged at the top of the crystallizer body, the output end of the motor (1) is connected with an outer magnetic cylinder (2), an inner magnetic cylinder (3) is arranged in the outer magnetic cylinder (2), a stirring shaft (4) is arranged at the lower part of the inner magnetic cylinder (3), the bottom of the stirring shaft (4) is provided with a stirring blade (5), the stirring shaft (4) is connected with a support frame (6) through a bearing, the stirring blades (5) are arranged in the guide shell (7), the guide shell (7) is connected with the inner wall of the crystallizer body through a connecting rod (8), a crystallization liquid outlet (9) is arranged at the bottom of the crystallizer body, an overflow port (10) and an exhaust port (11) are arranged at the upper part of the crystallizer body, a liquid inlet (12) is arranged at the lower part of the crystallizer body, and the lower part of the crystallizer body is in an inverted cone shape.

3. The anhydrous lithium chloride continuous crystallization method according to claim 2, characterized in that: the guide shell (7) is arranged below the support frame (6).

4. The anhydrous lithium chloride continuous crystallization method according to claim 2, characterized in that: the upper end of the stirring shaft (4) is fixedly connected with the inner magnetic cylinder (3).

5. The anhydrous lithium chloride continuous crystallization method according to claim 2, characterized in that: the stirring blades (5) turn up the feed liquid in the guide shell (7).

6. The anhydrous lithium chloride continuous crystallization method according to claim 2, characterized in that: the crystallizer body comprises an upper cover body (13), a cylinder body (14) and a lower inverted cone (15), and an overflow space is reserved between the top end of the cylinder body (14) and the upper cover body (13).

7. The method for the continuous crystallization of anhydrous lithium chloride according to claim 1, characterized in that: the volume of the magnetic stirring crystallizer is 20m, the temperature of the aqueous solution inside the magnetic stirring crystallizer is 120-150 m, the feeding speed at the bottom of the crystallizer is 2-4m for cultivation/h, the discharging speed of the mother solution at the bottom is 1-2m for cultivation/h, the flow speed of the circulating pump is 10-30m for cultivation/h, the steam pressure of the heater is 0.2-0.6mPa, the concentration of the dilute solution is 30-40%, the adding speed of the dilute solution is 2-4m for cultivation/h, and the circulating speed of the centrifugal mother solution is 6-10m for cultivation/h.

Technical Field

The invention relates to a crystallization method, in particular to an anhydrous lithium chloride crystallization method.

Background

The traditional anhydrous lithium chloride production method has a spray granulation technology and a gap crystallization technology, the density of a product of the spray granulation technology is too low, the product has the conditions of impurity wrapping and the like, the product is not suitable for pharmacy, catalysts and other purposes, and more problems exist in the aspect of lithium electrolysis. The production of anhydrous lithium chloride by the gap crystallization technology cannot realize industrialization, the labor intensity in the production process is high, and the energy consumption is serious.

The key of the continuous crystallization production equipment is whether the crystallizer is stable for a long time. Traditional crystallizer adopts crystallizer top installation motor, speed reducer and stirring frame, exists the stirring arm overlength, rocks easily, generally installs flexibility, elastic support or bearing near the stirring rake to prevent that the stirring rake from excessively rocking, and the interior solid-liquid environment of control crystallizer is undulant, guarantees that production process is continuously stable. The flexible or elastic support is generally made of flexible materials such as elastic rubber, polytetrafluoroethylene and graphite, and the materials generally have the defects of low temperature resistance, poor wear resistance, easy embrittlement during long-term operation and the like, and are frequently damaged, so that the equipment cannot operate for a long time, even the support is damaged, so that the quality of the product is changed, and the continuous operation of the equipment is restricted to a great extent. The bearing support is adopted to avoid the problems, but the bearing support is required to be positioned at the lower part of the guide shell, more crystals are already arranged at the lower part of the guide shell, and after sharp and irregular crystal particles are embedded into the bearing, the bearing is damaged, the motor is frequently damaged, and the equipment cannot continuously and stably run.

Disclosure of Invention

The purpose of the invention is as follows: the invention aims to overcome the defects in the prior art and provide the anhydrous lithium chloride crystallization method which is simple in steps, automatic and capable of producing stably for a long time.

The technical scheme is as follows: in order to solve the above technical problems, the present invention provides a method for continuously crystallizing anhydrous lithium chloride, comprising the steps of,

(1) continuously feeding and continuously crystallizing by adopting a magnetic stirring crystallizer, continuously discharging a mixture of crystal particles and an aqueous solution, feeding the mixture into a continuous centrifuge, and directly feeding a wet material obtained by centrifuging into a dryer to remove surface water;

(2) the dilute solution and the centrifugal mother solution continuously enter a heater together with the upper layer solution of the magnetic stirring crystallizer from a dilute solution inlet according to the flow rate proportion, and the tube pass of the heater is kept at a set flow rate by a circulating pump;

(3) pumping the heated lithium chloride water into the bottom of the guide shell at the lower end of the magnetic stirring crystallizer.

Further, the magnetic stirring crystallizer comprises a crystallizer body, a motor is arranged at the top of the crystallizer body, the output end of the motor is connected with an outer magnetic cylinder, an inner magnetic cylinder is arranged in the outer magnetic cylinder, a stirring shaft is arranged at the lower part of the inner magnetic cylinder, stirring blades are arranged at the bottom of the stirring shaft, the stirring shaft is connected with a support frame through a bearing, the stirring blades are arranged in a guide cylinder, the guide cylinder is connected with the inner wall of the crystallizer body through a connecting rod, a crystallization liquid outlet is arranged at the bottom of the crystallizer body, an overflow port and an exhaust port are arranged at the upper part of the crystallizer body, a liquid inlet is arranged at the lower part of the crystallizer body, and the lower part of the crystallizer body is.

Further, the draft tube is arranged below the support frame.

Furthermore, the upper end of the stirring shaft is fixedly connected with the inner magnetic cylinder.

Further, the stirring blades turn up the feed liquid in the guide shell.

Further, the crystallizer body comprises an upper cover body, a cylinder body and a lower inverted cone, and an overflow space is reserved between the top end of the cylinder body and the upper cover body.

Further, the volume of the magnetic stirring crystallizer is 20m, the temperature of the aqueous solution inside the magnetic stirring crystallizer is 120-150 m, the feeding speed at the bottom of the crystallizer is 2-4 m/h, the discharging speed of the mother solution at the bottom is 1-2 m/h, the flow speed of the circulating pump is 10-30 m/h, the steam pressure of the heater is 0.2-0.6mPa, the concentration of the dilute solution is 30-40%, the adding speed of the dilute solution is 2-4m when carrying out the top tree/h, and the circulating speed of the centrifugal mother solution is 6-10m when carrying out the top tree/h.

Has the advantages that: compared with the prior art, the invention has the following remarkable advantages: the invention adopts a special crystallizer to realize continuous feeding and continuous crystallization, continuously discharges a mixture of crystal particles and an aqueous solution to enter a continuous centrifuge, a wet material obtained by centrifugation directly enters a dryer to remove surface water, then a centrifugal mother solution and a dilute solution continuously enter a heater together with an upper layer solution of the crystallizer according to a flow rate ratio from a dilute solution inlet, a pipe pass of the heater is kept at a certain flow rate through a circulating pump to prevent the crystal particles from depositing and blocking the heater, heated lithium chloride is pumped into the bottom of a guide shell at the lower end of the crystallizer according to a certain flow rate, a stirring blade of the guide shell turns up the feed solution to enable the liquid to be in an upward backflow state, the guide shell blocks the shaking of the stirring blade to the peripheral environment of the crystallizer, the outer side of the guide shell is relatively static, when the concentration of lithium chloride reaches a crystallization point, the density of the crystal particles is greater than that of the aqueous solution and gradually sinks, the bottom of the crystallizer is inverted cone-shaped, which is convenient for the sinking of crystallized particles, the upper layer of the crystallizer is a static area, the concentration of lithium chloride is lower than that of the middle bottom, the upper layer aqueous solution overflows to flow to the heater after reaching a certain liquid level, so that the system of the crystallizer is relatively stable, the centrifuged liquid mother liquor is easy to accumulate impurities, the production process is discharged according to a certain proportion, the purity of the crystallization liquid can be kept, the product purity is convenient to improve, the crystallization can be produced by the method for 0.5-0.6T/h, and the daily yield can reach about 12-15 tons.

Drawings

FIG. 1 is a schematic view showing a connection structure of a magnetic stirring crystallizer, a heater and a circulation pump according to the present invention.

Detailed Description

The invention is further described below with reference to the figures and examples.

Example 1

As shown in FIG. 1, the method for the continuous crystallization of anhydrous lithium chloride according to the present invention comprises the following steps,

(1) continuously feeding and continuously crystallizing by adopting a magnetic stirring crystallizer, continuously discharging a mixture of crystal particles and an aqueous solution, feeding the mixture into a continuous centrifuge, and directly feeding a wet material obtained by centrifuging into a dryer to remove surface water;

(2) the dilute solution and the centrifugal mother solution continuously enter a heater together with the upper layer solution of the magnetic stirring crystallizer from a dilute solution inlet according to the flow rate proportion, and the tube pass of the heater is kept at a set flow rate by a circulating pump;

(3) pumping the heated lithium chloride water into the bottom of the guide shell at the lower end of the magnetic stirring crystallizer.

The magnetic stirring crystallizer comprises a crystallizer body, the crystallizer body comprises an upper cover body 13, a cylinder body 14 and a lower inverted cone 15, an overflow space is reserved between the top end of the cylinder body 14 and the upper cover body 13, a motor 1 is arranged at the top of the crystallizer body, the output end of the motor 1 is connected with an outer magnetic cylinder 2, an inner magnetic cylinder 3 is arranged in the outer magnetic cylinder 2, a stirring shaft 4 is fixedly connected with the lower part of the inner magnetic cylinder 3, stirring blades 5 are arranged at the bottom of the stirring shaft 4, the stirring shaft 4 is connected with a support frame 6 through a bearing, the stirring blades 5 are arranged in a guide cylinder 7, the stirring blades 5 turn up feed liquid in the guide cylinder 7, the guide cylinder 7 is connected with the inner wall of the crystallizer body through a connecting rod 8, the guide cylinder 7 is arranged below the support frame 6, a crystallization liquid outlet 9 is arranged at the bottom of the crystallizer body, an overflow port 10 and an exhaust port 11 are arranged, a liquid inlet 12 is arranged at the lower part of the crystallizer body, and the lower part of the crystallizer body is in an inverted cone shape.

The volume of magnetic stirring crystallizer is 20m, the temperature of its inside aqueous solution is 130 ℃, the bottom feeding speed of crystallizer is 2.5m for thin year/h, bottom mother liquor discharge speed is 1.2m for thin year/h, the flow rate of circulating pump is 20m for thin year/h, heater vapor pressure is 0.4mPa, thin liquid concentration is 32%, thin liquid addition speed is 2.5m for thin year/h, centrifugal mother liquor circulation speed is 7m for thin year/h.

Example 2

As shown in FIG. 1, the method for the continuous crystallization of anhydrous lithium chloride according to the present invention comprises the following steps,

(1) continuously feeding and continuously crystallizing by adopting a magnetic stirring crystallizer, continuously discharging a mixture of crystal particles and an aqueous solution, feeding the mixture into a continuous centrifuge, and directly feeding a wet material obtained by centrifuging into a dryer to remove surface water;

(2) the dilute solution and the centrifugal mother solution continuously enter a heater together with the upper layer solution of the magnetic stirring crystallizer from a dilute solution inlet according to the flow rate proportion, and the tube pass of the heater is kept at a set flow rate by a circulating pump;

(3) pumping the heated lithium chloride water into the bottom of the guide shell at the lower end of the magnetic stirring crystallizer.

The magnetic stirring crystallizer comprises a crystallizer body, the crystallizer body comprises an upper cover body 13, a cylinder body 14 and a lower inverted cone 15, an overflow space is reserved between the top end of the cylinder body 14 and the upper cover body 13, a motor 1 is arranged at the top of the crystallizer body, the output end of the motor 1 is connected with an outer magnetic cylinder 2, an inner magnetic cylinder 3 is arranged in the outer magnetic cylinder 2, a stirring shaft 4 is fixedly connected with the lower part of the inner magnetic cylinder 3, stirring blades 5 are arranged at the bottom of the stirring shaft 4, the stirring shaft 4 is connected with a support frame 6 through a bearing, the stirring blades 5 are arranged in a guide cylinder 7, the stirring blades 5 turn up feed liquid in the guide cylinder 7, the guide cylinder 7 is connected with the inner wall of the crystallizer body through a connecting rod 8, the guide cylinder 7 is arranged below the support frame 6, a crystallization liquid outlet 9 is arranged at the bottom of the crystallizer body, an overflow port 10 and an exhaust port 11 are arranged, a liquid inlet 12 is arranged at the lower part of the crystallizer body, and the lower part of the crystallizer body is in an inverted cone shape.

The volume of magnetic stirring crystallizer is 20m, the temperature of its inside aqueous solution is 140 ℃, the bottom feeding speed of crystallizer is 3.5m for thin year/h, bottom mother liquor discharge speed is 1.7m for thin year/h, the flow rate of circulating pump is 24m for thin year/h, heater vapor pressure is 0.5mPa, thin liquid concentration is 38%, thin liquid addition speed is 2.8m for thin year/h, centrifugal mother liquor circulation speed is 9m for thin year/h.

The invention adopts a special crystallizer to realize continuous feeding and continuous crystallization, continuously discharges a mixture of crystal particles and an aqueous solution to enter a continuous centrifuge, a wet material obtained by centrifugation directly enters a dryer to remove surface water, then a centrifugal mother solution and a dilute solution continuously enter a heater together with an upper layer solution of the crystallizer according to a flow rate ratio from a dilute solution inlet, a pipe pass of the heater is kept at a certain flow rate through a circulating pump to prevent the crystal particles from depositing and blocking the heater, heated lithium chloride is pumped into the bottom of a guide shell at the lower end of the crystallizer according to a certain flow rate, a stirring blade of the guide shell turns up the feed solution to enable the liquid to be in an upward backflow state, the guide shell blocks the shaking of the stirring blade to the peripheral environment of the crystallizer, the outer side of the guide shell is relatively static, when the concentration of lithium chloride reaches a crystallization point, the density of the crystal particles is greater than that of the aqueous solution and gradually sinks, the bottom of the crystallizer is inverted cone-shaped, which is convenient for the sinking of crystallized particles, the upper layer of the crystallizer is a static area, the concentration of lithium chloride is lower than that of the middle bottom, the upper layer aqueous solution overflows to flow to the heater after reaching a certain liquid level, so that the system of the crystallizer is relatively stable, the centrifuged liquid mother liquor is easy to accumulate impurities, the production process is discharged according to a certain proportion, the purity of the crystallization liquid can be kept, the product purity is convenient to improve, the crystallization can be produced by the method for 0.5-0.6T/h, and the daily yield can reach about 12-15 tons.

The present invention provides a thought and a method, and a method and a way for implementing the technical scheme are many, the above is only a preferred embodiment of the present invention, it should be noted that, for a person skilled in the art, a plurality of improvements and modifications can be made without departing from the principle of the present invention, and the improvements and modifications should be regarded as the protection scope of the present invention, and each component not explicitly described in the embodiment can be implemented by the prior art.