Device for removing hydrogen chloride from lithium hexafluorophosphate

Abstract

The utility model relates to a device for removing hydrogen chloride from lithium hexafluorophosphate. According to the technical scheme, the output end of a mixed gas buffer tank is connected with a primary cooler, an outlet of the mixed gas buffer tank is connected with an organic solvent buffer tank, a shell pass top outlet of the primary cooler is sequentially connected with a first condenser, a second condenser and a third condenser through pipelines, and a top outlet of the third condenser is connected with a spraying tank through a pipeline; the top of the spraying tank is connected with a tail gas treater through a pipeline, the bottom of the spraying tank is connected with a concentrated hydrochloric acid tank, and a multi-stage spraying head is mounted in an inner cavity of the spraying tank. The device has the beneficial effects that hydrogen fluoride can be separated as clean as possible through three times of condensation; and the hydrogen chloride gas is fed into the spraying tank, is interacted with the multi-stage spraying head through the gas atomization spraying head and is circularly sprayed, so that the concentration of the hydrochloric acid is improved, the hydrogen chloride is effectively removed, the cyclic utilization of the organic solvent, the hydrogen chloride and the hydrogen fluoride is also realized, and the economic benefit is greatly improved.

Description

Technical Field

[0001] The utility model relates to a preparation device of lithium hexafluorophosphate, in particular to a device for removing hydrogen chloride from lithium hexafluorophosphate. Background Art

[0002] At present, lithium hexafluorophosphate is a commonly used electrolyte material in liquid lithium-ion batteries. With the rapid development of electric vehicles, the demand for power batteries has increased rapidly, and the demand and quality requirements for lithium hexafluorophosphate have also increased rapidly. Currently, most industrial methods for preparing lithium hexafluorophosphate involve synthesizing phosphorus pentafluoride and lithium fluoride in an organic solvent. However, when preparing lithium hexafluorophosphate, a mixed gas including hydrogen fluoride and hydrogen chloride is generated, which requires removing the above-mentioned hydrogen fluoride and hydrogen chloride components and enabling recycling to improve its economic benefits. Summary of the Utility Model

[0003] The purpose of the utility model is to provide a device for removing hydrogen chloride from lithium hexafluorophosphate aiming at the above-mentioned defects existing in the prior art, which can effectively remove hydrogen fluoride and hydrogen chloride components and enable recycling, thereby greatly improving economic benefits.

[0004] A device for removing hydrogen chloride from lithium hexafluorophosphate mentioned in the utility model has the following technical solution: it includes a mixed gas buffer tank in the synthesis section, a primary cooler, an organic solvent buffer tank, an organic solvent storage tank, a first condenser, a second condenser, a third condenser, a spray tank, a concentrated hydrochloric acid tank, and a tail gas processor. The output end of the mixed gas buffer tank in the synthesis section is connected to the shell-side inlet of the primary cooler through a pipeline. The bottom outlet of the shell side of the primary cooler is connected to the organic solvent buffer tank through a pipeline. The top outlet of the shell side of the primary cooler is connected to the first condenser, the second condenser, and the third condenser in sequence through a pipeline. The top outlet of the third condenser is connected to the spray tank through a pipeline. The top of the spray tank is connected to the tail gas processor through a pipeline. The bottom of the spray tank is connected to the concentrated hydrochloric acid tank, and a multi-stage spray head is installed in the inner cavity of the spray tank.

[0005] Preferably, the lower end of the first condenser is connected to a first hydrofluoric acid temporary storage tank through a pipeline, the lower end of the second condenser is connected to a second hydrofluoric acid temporary storage tank through a pipeline, and the lower end of the third condenser is connected to a third hydrofluoric acid temporary storage tank through a pipeline.

[0006] Preferably, the bottom of the spray tank is connected to the concentrated hydrochloric acid tank through a pipeline and a control valve.

[0007] Preferably, the lower side of the spray tank is connected to a dilute hydrochloric acid tank through a pipeline, and the lower side of the dilute hydrochloric acid tank is connected to the multi-stage spray head at the upper part of the inner cavity of the spray tank through a pipeline and a circulation pump.

[0008] Preferably, a gas atomizing nozzle is arranged below the multi-stage spray head of the spray tank.

[0009] Preferably, the above gas atomizing nozzle includes a branch pipe, a side pipe, an atomizing head, and a main connecting pipe. The upper end of the main connecting pipe is connected to a plurality of branch pipes arranged horizontally. A plurality of side pipes are distributed outside the branch pipes, and an atomizing head is provided at the end of each side pipe.

[0010] Preferably, there are more than three groups of the above branch pipes and more than three groups of side pipes.

[0011] The beneficial effects of the present utility model are as follows: By sending the mixed gas into the first condenser, the second condenser, and the third condenser and controlling the condensation temperature at 3 - 19 degrees, hydrogen fluoride therein can be condensed into a liquid, and hydrogen fluoride can be separated as clean as possible after three condensations; then the hydrogen chloride gas is sent into the spray tank, and through the interaction of the gas atomizing nozzle and the multi-stage spray head, the hydrogen chloride gas can react with water to form dilute hydrochloric acid. In order to increase the concentration of the dilute hydrochloric acid, the lower side of the spray tank can be connected to the dilute hydrochloric acid tank, and the dilute hydrochloric acid tank is connected to the spray tank through a pipeline and a circulation pump, enabling cyclic spraying and increasing the concentration of hydrochloric acid. The present utility model effectively removes hydrogen chloride and also realizes the recycling of organic solvents, hydrogen chloride, and hydrogen fluoride, greatly improving economic benefits. Description of the Drawings

[0012] Figure 1 is a schematic structural diagram of the present utility model;

[0013] Figure 2 is a schematic structural diagram of the gas atomizing nozzle;

[0014] In the above figure: the mixed gas buffer tank 1 of the synthesis section, the primary cooler 2, the organic solvent buffer tank 3, the organic solvent storage tank 4, the first condenser 5, the second condenser 6, the third condenser 7, the first hydrofluoric acid temporary storage tank 8, the second hydrofluoric acid temporary storage tank 9, the third hydrofluoric acid temporary storage tank 10, the spray tank 11, the concentrated hydrochloric acid tank 12, the dilute hydrochloric acid tank 13, the circulation pump 14, the tail gas processor 15, the control valve 16, the second control valve 17, the multi-stage spray head 11.1, the gas atomizing nozzle 11.2, the branch pipe 11.2.1, the side pipe 11.2.2, the atomizing head 11.2.3, the main connecting pipe 11.2.4. Detailed Embodiments

[0015] The following describes the preferred embodiments of the present utility model with reference to the drawings. It should be understood that the preferred embodiments described herein are only for illustrating and explaining the present utility model and are not used to limit the present utility model.

[0016] Example 1, referring to Figure 1 and Figure 2, a hydrogen chloride removal device for lithium hexafluorophosphate according to the present utility model, comprising a mixed gas buffer tank 1 in the synthesis section, a primary cooler 2, an organic solvent buffer tank 3, an organic solvent storage tank 4, a first condenser 5, a second condenser 6, a third condenser 7, a spray tank 11, a concentrated hydrochloric acid tank 12, and a tail gas processor 15. The output end of the mixed gas buffer tank 1 in the synthesis section is connected to the shell-side inlet of the primary cooler 2 through a pipeline. The bottom outlet of the shell side of the primary cooler 2 is connected to the organic solvent buffer tank 3 through a pipeline. The top outlet of the shell side of the primary cooler 2 is connected to the first condenser 5, the second condenser 6, and the third condenser 7 in sequence through a pipeline. The top outlet of the third condenser 7 is connected to the spray tank 11 through a pipeline. The top of the spray tank 11 is connected to the tail gas processor 15 through a pipeline. The bottom of the spray tank 11 is connected to the concentrated hydrochloric acid tank 12. A multi-stage spray head 11.1 is installed in the inner cavity of the spray tank 11.

[0017] Among them, the lower end of the first condenser 5 is connected to the first hydrofluoric acid temporary storage tank 8 through a pipeline. The lower end of the second condenser 6 is connected to the second hydrofluoric acid temporary storage tank 9 through a pipeline. The lower end of the third condenser 7 is connected to the third hydrofluoric acid temporary storage tank 10 through a pipeline.

[0018] The bottom of the spray tank 11 is connected to the concentrated hydrochloric acid tank 12 through a pipeline and a control valve 16.

[0019] The lower side of the spray tank 11 is connected to a dilute hydrochloric acid tank 13 through a pipeline. The lower side of the dilute hydrochloric acid tank 13 is connected to the multi-stage spray head 11.1 at the upper part of the inner cavity of the spray tank 11 through a pipeline and a circulation pump 14, which can improve the absorption efficiency of hydrogen chloride gas.

[0020] A gas atomizing nozzle 11.2 is provided below the multi-stage spray head 11.1 of the spray tank 11.

[0021] Refer to Figure 2 , the gas atomizing nozzle 11.2 mentioned in the present utility model comprises a branch pipeline 11.2.1, a side pipeline 11.2.2, an atomizing head 11.2.3, and a main connecting pipe 11.2.4. The upper end of the main connecting pipe 11.2.4 is connected to a plurality of horizontally arranged branch pipelines 11.2.1. A plurality of side pipelines 11.2.2 are distributed on the outer side of the branch pipeline 11.2.1 and form a dendritic structure. An atomizing head 11.2.3 is provided at the end of each side pipeline 11.2.2. This structure can increase the contact area with the water coming down from the upper multi-stage spray head 11.1 and improve the absorption efficiency of hydrogen chloride.

[0022] Among them, there are more than three groups of the branch pipelines 11.2.1 and more than three groups of the side pipelines 11.2.2.

[0023] When the utility model is in use, the mixed gas in the mixed gas buffer tank 1 in the synthesis section is sent into the primary cooler 2 to be cooled to 20°C - 30°C, so as to cool the organic solvent in the mixed gas into a liquid. The organic solvent is methyl sulfoxide, whose melting point is 18.4°C and boiling point is 189°C. Then, it flows along the bottom outlet of the shell side of the primary cooler 2 to the organic solvent buffer tank 3, and the lower part of the organic solvent buffer tank 3 is connected to the organic solvent storage tank 4 through a pipeline and a second control valve 17. In addition, for the hydrogen fluoride and hydrogen chloride gases in the mixed gas, the boiling point of hydrogen fluoride is 19.5°C and the boiling point of hydrogen chloride is -85°C. Therefore, the mixed gas is sent into the first condenser 5, the second condenser 6, and the third condenser 7, and the condensation temperature is controlled at 3 - 19°C, so that the hydrogen fluoride in it can be condensed into a liquid, and the hydrogen fluoride can be separated as clean as possible after three condensations. Then, the remaining hydrogen chloride gas, etc. are sent into the spray tank 11. Through the interaction between the gas atomizing nozzle 11.2 and the multi-stage spray head 11.1, the hydrogen chloride gas can react with water to form dilute hydrochloric acid. In order to increase the concentration of the dilute hydrochloric acid, the lower side of the spray tank 11 can be connected to the dilute hydrochloric acid tank 13, and the dilute hydrochloric acid tank 13 is connected to the spray tank 11 through a pipeline and a circulation pump 14, so that it can be circulated and sprayed to increase the concentration of hydrochloric acid. When the concentration reaches a certain level, the control valve 16 is opened to send the hydrochloric acid in the spray tank 11 into the concentrated hydrochloric acid tank 12, realizing recycling, thus greatly improving the economic benefits. And the remaining tail gas is transported through the top outlet of the spray tank 11 to the tail gas processor 15 for treatment.

[0024] Embodiment 2, a hydrogen chloride removal device for lithium hexafluorophosphate mentioned in the utility model, includes a synthesis section mixed gas buffer tank 1, a primary cooler 2, an organic solvent buffer tank 3, an organic solvent storage tank 4, a first condenser 5, a second condenser 6, a third condenser 7, a spray tank 11, a concentrated hydrochloric acid tank 12, and a tail gas processor 15. The output end of the synthesis section mixed gas buffer tank 1 is connected to the shell side inlet of the primary cooler 2 through a pipeline, the bottom outlet of the shell side of the primary cooler 2 is connected to the organic solvent buffer tank 3 through a pipeline, the top outlet of the shell side of the primary cooler 2 is connected to the first condenser 5, the second condenser 6, and the third condenser 7 in sequence through a pipeline, the top outlet of the third condenser 7 is connected to the spray tank 11 through a pipeline, the top of the spray tank 11 is connected to the tail gas processor 15 through a pipeline, the bottom of the spray tank 11 is connected to the concentrated hydrochloric acid tank 12, and a multi-stage spray head 11.1 is installed in the inner cavity of the spray tank 11.

[0025] The difference from Embodiment 1 is:

[0026] In order to reduce energy consumption, the condensed water of the first condenser 5, the second condenser 6, and the third condenser 7 can be recycled, and the condensation temperature can be controlled between 0 and 19 degrees. Therefore, at the beginning, the chilled water is sent into the tube-side inlet of the third condenser 7. The tube-side outlet of the third condenser 7 is connected to the tube-side inlet of the second condenser 6, and the tube-side outlet of the second condenser 6 is connected to the tube-side inlet of the first condenser 5. By controlling the temperature not to exceed 19 degrees, the separation of hydrogen chloride and hydrogen fluoride can be achieved.

[0027] The above are only the preferred embodiments of the present invention. Any person skilled in the art may modify the present invention by using the technical solutions described above or modify it into an equivalent technical solution. Therefore, any simple modification or equivalent transformation made according to the technical solutions of the present invention falls within the scope of protection required by the present invention.

Claims

1. A device for removing hydrogen chloride from lithium hexafluorophosphate, characterized in that: The invention comprises a synthesis section mixed gas buffer tank (1), a primary cooler (2), an organic solvent buffer tank (3), an organic solvent storage tank (4), a first condenser (5), a second condenser (6), a third condenser (7), a spray tank (11), a concentrated hydrochloric acid tank (12), and an exhaust gas processor (15). The output end of the synthesis section mixed gas buffer tank (1) is connected to the shell side inlet of the primary cooler (2) through a pipeline, the shell side bottom outlet of the primary cooler (2) is connected to the organic solvent buffer tank (3) through a pipeline, the shell side top outlet of the primary cooler (2) is connected to the first condenser (5), the second condenser (6), and the third condenser (7) in sequence through a pipeline, the top outlet of the third condenser (7) is connected to the spray tank (11) through a pipeline, the top of the spray tank (11) is connected to the exhaust gas processor (15) through a pipeline, the bottom of the spray tank (11) is connected to the concentrated hydrochloric acid tank (12), and a multi-stage spray head (11.1) is installed in the inner cavity of the spray tank (11).

2. The device for removing hydrogen chloride from lithium hexafluorophosphate according to claim 1, characterized in that: The lower end of the first condenser (5) is connected to the first hydrofluoric acid temporary storage tank (8) through a pipeline, the lower end of the second condenser (6) is connected to the second hydrofluoric acid temporary storage tank (9) through a pipeline, and the lower end of the third condenser (7) is connected to the third hydrofluoric acid temporary storage tank (10) through a pipeline.

3. The device for removing hydrogen chloride from lithium hexafluorophosphate according to claim 2, characterized in that: The bottom of the spray tank (11) is connected to the concentrated hydrochloric acid tank (12) via a pipeline and a control valve (16).

4. The device for removing hydrogen chloride from lithium hexafluorophosphate according to claim 3, characterized in that: The lower side of the spray tank (11) is connected to the dilute hydrochloric acid tank (13) via a pipeline, and the lower side of the dilute hydrochloric acid tank (13) is connected to a multi-stage spray head (11.1) at the upper part of the inner cavity of the spray tank (11) via a pipeline and a circulation pump (14).

5. The device for removing hydrogen chloride from lithium hexafluorophosphate according to claim 4, characterized in that: A gas atomizing nozzle (11.2) is provided at the bottom of the multi-stage spray head (11.1) of the spray tank (11).

6. The device for removing hydrogen chloride from lithium hexafluorophosphate according to claim 5, characterized in that: The gas atomizing nozzle (11.2) comprises a branch pipe (11.2.1), a side pipe (11.2.2), an atomizing head (11.2.3), and a main connecting pipe (11.2.4); the upper end of the main connecting pipe (11.2.4) is connected to a plurality of branch pipes (11.2.1) arranged in a horizontal direction; a plurality of side pipes (11.2.2) are distributed outside the branch pipes (11.2.1); and an atomizing head (11.2.3) is arranged at the end of each side pipe (11.2.2).

7. The device for removing hydrogen chloride from lithium hexafluorophosphate according to claim 6, characterized in that: The branch pipes (11.2.1) are provided in more than three groups, and the side pipes (11.2.2) are provided in more than three groups.

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