Equipment for preparing high-purity halide wet electronic chemicals by adopting sub-boiling distillation method

Abstract

The utility model discloses equipment for preparing high-purity halide wet electronic chemicals by adopting a sub-boiling distillation method, and belongs to the technical field of wet electronic chemicals. The device comprises a sub-boiling distiller, wherein a top outlet of the sub-boiling distiller is sequentially connected with a first-stage absorption system, a second-stage absorption system and a third-stage absorption system; the first-stage absorption system comprises a first-stage falling film absorber and a first-stage absorption tank, and the bottom of the first-stage falling film absorber is connected to the first-stage absorption tank; a top gas outlet of the first-stage falling film absorber is connected with the second-stage absorption system; the second-stage absorption system comprises a second-stage falling film absorber and a second-stage absorption tank, and the bottom of the second-stage falling film absorber is connected to the second-stage absorption tank; a top gas outlet of the second-stage falling film absorber is connected to a third-stage absorption system; the third-stage absorption system comprises an absorption tower; the sub-boiling distiller comprises a tower main body, a heating jacket is arranged at the middle lower part outside the tower main body, and the heating jacket is communicated with a circulating water pipeline. The device is low in heat source temperature, low in consumption and low in energy consumption.

Description

Technical Field

[0001] The invention belongs to the technical field of wet electronic chemicals, and in particular relates to a device for preparing high-purity halide wet electronic chemicals by a sub-boiling distillation method. Background Art

[0002] High-purity halides are a type of common wet electronic chemicals, generally including hydrobromic acid, hydrochloric acid, and hydrofluoric acid. They are mainly used in the cleaning process of integrated circuit manufacturing to clean various metals, organic matter, and particulate matter. Integrated circuits have high purity requirements for wet electronic chemicals, which are basically concentrated at levels above G3. The larger the wafer size, the higher the purity requirement. 12-inch wafer manufacturing generally requires levels above G4. Therefore, G4 and G5 grade high-purity halides have higher requirements for the preparation method.

[0003] The commonly used method for purifying high-purity halides is to separate gaseous halides from halide aqueous solutions, filter, dehydrate and dry them, and then absorb them in ultrapure water. However, the current high-purity halide preparation methods have the disadvantages of low recovery rate, high energy consumption and large equipment investment.

[0004] In addition, the general distillation operation must make the liquid in a violent boiling state, forming an aerosol in the distillation kettle, that is, a gas containing suspended droplets of distilled liquid, which enters the condenser or is absorbed by water into the product. Since these droplets are not gasified and purified, they still contain a certain amount of various impurities, which contaminate the quality of the distillate and reduce the quality of the high-purity halide. Summary of the invention

[0005] In order to obtain high-purity halide wet electronic chemicals, the present application provides a new device for preparing high-purity halide wet electronic chemicals.

[0006] Based on the above purpose, the present invention adopts the following technical solution:

[0007] A device for preparing high-purity halide wet electronic chemicals by sub-boiling distillation method, comprising a sub-boiling distiller, wherein high-purity halide from a reflux tank of a halide refining tower is transported to the bottom of the sub-boiling distiller through a pipeline and contacts an absorbent. The top outlet of the sub-boiling distiller is sequentially connected to a primary absorption system, a secondary absorption system and a tertiary absorption system; the primary absorption system comprises a primary falling film absorber and a primary absorption tank, and the bottom of the primary falling film absorber is connected to the primary absorption tank; the top gas outlet of the primary falling film absorber is connected to the secondary absorption system; the secondary absorption system comprises a secondary falling film absorber and a secondary absorption tank, and the bottom of the secondary falling film absorber is connected to the secondary absorption tank; the top gas outlet of the secondary falling film absorber is connected to a tertiary absorption system, and the tertiary absorption system comprises an absorption tower; wherein the shell side of the primary falling film absorber and the secondary falling film absorber is connected to a cooling water pipeline, and 7°C cooling water is introduced; the sub-boiling distiller comprises a tower body, and a heating jacket is provided in the middle and lower part outside the tower body, and the heating jacket is connected to a circulating water pipeline.

[0008] Furthermore, a primary circulation pump is connected to the bottom of the primary absorption tank, and an outlet of the primary circulation pump is connected to the upper part of the primary falling film absorber.

[0009] Furthermore, the outlet of the primary circulation pump is connected in parallel with two pipelines, one of which is connected to the upper part of the primary falling film absorber, and the other is connected to the electronic grade hydrochloric acid filling system.

[0010] Furthermore, a secondary circulation pump is connected to the bottom of the secondary absorption tank, and an outlet of the secondary circulation pump is connected to the upper part of the secondary falling film absorber.

[0011] Furthermore, the outlet of the secondary circulation pump is connected to two pipelines in parallel, one of which is connected to the upper part of the secondary falling film absorber, and the other is connected to the primary absorption tank.

[0012] Furthermore, the liquid outlet at the bottom of the absorption tower is connected to a cooler via a three-stage circulation pump, and the cooler is connected to a sprayer at the top of the absorption tower.

[0013] Furthermore, the outlet of the tertiary circulation pump is connected in parallel with two pipelines, one of which is connected to the cooler and the other is connected to the secondary absorption tank.

[0014] Furthermore, a tail gas treatment device is connected to the top of the absorption tower.

[0015] Preferably, the hydrogen halide is hydrogen chloride, hydrogen fluoride or hydrogen bromide.

[0016] The process flow of the above device is as follows:

[0017] (1) Feed industrial-grade liquid hydrogen halide from the lower part of the sub-boiling distiller, and use 25°C circulating water as a heat source to enter the external heating jacket of the sub-boiling distiller; make the liquid level in the sub-boiling distiller 60%, the pressure in the sub-boiling distiller 38barG, and the rising air flow rate of hydrogen chloride gas in the sub-boiling distiller 3-6m / h. Industrial-grade liquid hydrogen halide is in a sub-boiling state in the sub-boiling distiller, and the liquid hydrogen halide will not rise along the wall. The hydrogen halide gas is discharged from the top of the sub-boiling distiller and enters the first-stage falling film absorber after decompression; the residual material is discharged from the bottom of the sub-boiling distiller;

[0018] (2) The hydrogen chloride gas not absorbed by the primary falling film absorber enters the secondary falling film absorber and the absorption tower in turn; the hydrogen halide solution discharged from the bottom of the primary falling film absorber enters the primary absorption tank, and the hydrogen halide in the absorption tank is used as a circulating absorption liquid and enters the top of the primary falling film absorber through the primary circulation pump until the mass concentration of the hydrogen halide solution reaches the requirement of electronic grade hydrogen halide, and the circulation is stopped to obtain electronic grade hydrogen halide; the absorption temperature of the primary falling film absorber and the secondary falling film absorber is lower than 20°C.

[0019] The unabsorbed hydrogen chloride gas in the secondary falling film absorber is discharged and enters the absorption tower, the hydrogen halide solution discharged from the bottom of the secondary falling film absorber enters the secondary absorption tank, and the hydrogen halide in the absorption tank enters the top of the secondary falling film absorber as a circulating absorption liquid through the secondary circulation pump. The hydrogen halide solution discharged from the kettle of the absorption tower enters the top of the absorption tower as a circulating absorption liquid through the tertiary circulation pump.

[0020] Part of the hydrogen halide solution in the secondary absorption tank enters the top of the secondary falling film absorber through the secondary circulation pump for circulation absorption. When the concentration reaches 22-25%, part of the hydrogen halide solution is transferred to the primary absorption tank. Part of the hydrogen halide solution discharged from the kettle of the absorption tower enters the top of the absorption tower through the tertiary circulation pump for circulation absorption. When the concentration reaches 14-17%, part of the hydrogen halide solution is transferred to the secondary absorption tank.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] This application adopts sub-boiling distillation technology to purify halides. Taking the high-purity hydrochloric acid preparation technology as an example, 25°C circulating water is used as a heat source to enter the heating jacket outside the sub-boiling distiller. The halides are not in direct contact with the heat source in the sub-boiling distiller. Heat conduction is carried out through the jacket wall of the sub-boiling distiller to achieve the evaporation of hydrogen halide gas. The required amount of hot water is only 0.3 times that of hydrochloric acid. The heat source temperature is low, the amount is small, and the energy consumption is small. At the same time, since the temperature in the sub-boiling distiller is only 25°C, which is slightly higher than the evaporation temperature of liquefied hydrogen chloride at 40barG (20°C), the temperature of the sub-boiling distiller is maintained at 18-19°C, which is lower than the boiling point of liquefied hydrogen chloride. The liquid phase does not boil, and does not produce aerosols produced during normal boiling. The evaporated hydrogen chloride gas does not contain aerosols, which can prevent liquid hydrogen chloride droplets from being brought into the gas phase without being vaporized.

[0023] At the same time, the raw material high-purity hydrogen chloride refining tower reflux tank enters the sub-boiling distiller, and 80% of the hydrogen chloride is reduced in pressure from the pressure reducing valve and enters the lower end of the first falling film absorber, and countercurrently contacts with the dilute hydrochloric acid from the second falling film absorber. The unabsorbed hydrogen chloride enters the lower end of the second absorber and countercurrently contacts with the dilute hydrochloric acid from the absorption tower. The hydrogen chloride that has not been absorbed enters the bottom of the absorption tower from the top of the second falling film absorber, and is absorbed by ultrapure water from the outside, and the non-condensable gas enters the tail gas treatment unit. 20% of the hydrogen chloride in the tower bottom enters the industrial-grade hydrogen chloride filling unit, and the single hydrogen chloride recovery rate of the device is 80%. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is the process flow chart of Example 1.

[0025] In the figure, 1. sub-boiling distiller; 2. primary falling film absorber; 3. primary absorption tank; 4. primary circulation pump; 5. secondary falling film absorber; 6. secondary absorption tank; 7. secondary circulation pump; 8. absorption tower; 9. tertiary circulation pump; 10. cooler; 11. tail gas treatment device. DETAILED DESCRIPTION

[0026] A device for preparing high-purity halide wet electronic chemicals by sub-boiling distillation method comprises a sub-boiling distiller 1. High-purity halide from a reflux tank of a halide refining tower is transported to the bottom of the sub-boiling distiller 1 through a pipeline and contacts with an absorbent. The top outlet of the sub-boiling distiller 1 is sequentially connected to a primary absorption system, a secondary absorption system and a tertiary absorption system.

[0027] The sub-boiling distiller 1 comprises a tower body, a heating jacket is arranged at the middle and lower part outside the tower body, the heating jacket is connected to the circulating water pipeline, and the circulating water at 25° C. enters the heating jacket outside the sub-boiling distiller 11 as a heat source to heat the liquefied hydrogen chloride in the tower body to make it in a sub-boiling state, and the hydrogen chloride gas without liquid droplets is evaporated and absorbed by ultrapure water to form high-purity hydrochloric acid.

[0028] The primary absorption system includes a primary falling film absorber 2 and a primary absorption tank 3. The bottom of the primary falling film absorber 2 is connected to the primary absorption tank 3; the top gas outlet of the primary falling film absorber 2 is connected to the secondary absorption system, and the bottom of the primary absorption tank 3 is connected to a primary circulation pump 4. The outlet of the primary circulation pump 4 is connected to two pipelines in parallel, one of which is connected to the upper part of the primary falling film absorber 2, and the other is connected to the electronic grade hydrochloric acid filling system.

[0029] The secondary absorption system includes a secondary falling film absorber 5 and a secondary absorption tank 6. The bottom of the secondary falling film absorber 5 is connected to the secondary absorption tank 6. The bottom of the secondary absorption tank 6 is connected to a secondary circulation pump 7. The outlet of the secondary circulation pump 7 is connected to two pipelines in parallel, one of which is connected to the upper part of the secondary falling film absorber 5, and the other is connected to the primary absorption tank 3.

[0030] The top gas outlet of the secondary falling film absorber 5 is connected to the tertiary absorption system, which includes an absorption tower 8. The liquid outlet at the bottom of the absorption tower is connected to a cooler 10 through a tertiary circulation pump 9, and the cooler is connected to the sprayer at the top of the absorption tower 8. The outlet of the tertiary circulation pump 9 is connected to two pipelines in parallel, one of which is connected to the cooler 10 and the other is connected to the secondary absorption tank 6. The top of the absorption tower 8 is connected to a tail gas treatment device 11.

[0031] The operating steps of the above equipment are as follows:

[0032] (1) Taking high-purity hydrochloric acid as an example, the purified liquefied hydrogen chloride is introduced into the sub-boiling distiller 1 below the liquid level, the liquid level in the sub-boiling distiller 1 is controlled to be 50-80%, and circulating water at 25°C is used as a heat source to enter the external heating jacket of the sub-boiling distiller 1; the heating rate in the sub-boiling distiller 1 ensures that the gas velocity of the gas phase in the tower is 3m / S, and the temperature in the tower is 18-19°C, so that the liquefied hydrogen chloride is in a sub-boiling state in the sub-boiling distiller 1, and the hydrogen chloride gas without liquid droplets is discharged from the top of the sub-boiling distiller 1, and enters the primary falling film absorber 2 after decompression; the remaining hydrochloric acid aqueous solution with a mass concentration of 20% is discharged from the bottom of the sub-boiling distiller 1, and then enters the industrial-grade hydrogen chloride filling unit.

[0033] (2) A portion of the hydrogen chloride gas entering the primary falling film absorber 2 is absorbed by ultrapure water below 20°C to form an electronic grade hydrochloric acid solution, which then enters the primary absorption tank 3. The unabsorbed hydrogen chloride gas is discharged from the top and enters the secondary falling film absorber 5. The hydrochloric acid solution in the primary absorption tank 3 is cooled and then enters the top of the primary falling film absorber 2 through the primary circulation pump 4 as a circulating absorption liquid until the hydrochloric acid solution in the primary absorption tank 3 reaches 36%-38%, at which time the electronic grade hydrochloric acid in the primary absorption tank 3 is transported to the filling system.

[0034] (3) A portion of the hydrogen chloride gas entering the secondary falling film absorber 5 is absorbed by the circulating absorption liquid below 20°C to form a hydrochloric acid solution, which then enters the secondary absorption tank 6. The unabsorbed hydrogen chloride gas is discharged from the top and enters the bottom of the absorption tower 8. A portion of the hydrochloric acid solution in the secondary absorption tank 6 enters the top of the secondary falling film absorber 5 through the secondary circulation pump 7. When the mass concentration of the hydrochloric acid solution reaches 20%-25%, a portion of it is circulated to the primary absorption tank 3, mixed with the hydrochloric acid discharged from the bottom of the primary falling film absorber 2, and then used as the circulating absorption liquid, which is circulated to the primary falling film absorber 2.

[0035] (4) The unabsorbed hydrogen chloride gas continues to be in countercurrent contact with ultrapure water or circulating absorption liquid in the absorption tower 8 and continues to be absorbed. The low-concentration hydrochloric acid formed in the bottom of the tower is cooled by the cooler 10 and circulated to the top of the absorption tower 8 as the circulating absorption liquid. When the mass concentration of the low-concentration hydrochloric acid reaches 5%-10%, part of it circulates to the secondary absorption tank 6, mixes with the hydrochloric acid discharged from the bottom of the secondary falling film absorber 5, and is used as the circulating absorption liquid to circulate to the secondary falling film absorber 6; the hydrogen chloride gas discharged from the top of the absorption tower 8 goes to the alkaline washing process.

[0036] At the same time, the absorption liquid of the present application is circulated in the absorption tower 8, the secondary falling film absorber 5, and the primary falling film absorber 2, which can effectively reduce the use of ultrapure water, reduce the direct use of absorbent, and reduce production costs.

Claims

1. A device for preparing high-purity halide wet electronic chemicals by sub-boiling distillation, characterized in that: It comprises a sub-boiling distiller, the top outlet of which is sequentially connected to a primary absorption system, a secondary absorption system and a tertiary absorption system; the primary absorption system comprises a primary falling film absorber and a primary absorption tank, the bottom of the primary falling film absorber is connected to the primary absorption tank; the top gas outlet of the primary falling film absorber is connected to the secondary absorption system; the secondary absorption system comprises a secondary falling film absorber and a secondary absorption tank, the bottom of the secondary falling film absorber is connected to the secondary absorption tank; The top gas outlet of the secondary falling film absorber is connected to a tertiary absorption system, which includes an absorption tower; wherein the shell sides of the primary falling film absorber and the secondary falling film absorber are connected to a cooling water pipeline; the sub-boiling distiller includes a tower body, and a heating jacket is provided in the middle and lower part outside the tower body, and the heating jacket is connected to a circulating water pipeline.

2. The device for preparing high-purity halide wet electronic chemicals by sub-boiling distillation method according to claim 1, characterized in that: The bottom of the primary absorption tank is connected with a primary circulation pump, and the outlet of the primary circulation pump is connected to the upper part of the primary falling film absorber.

3. The device for preparing high-purity halide wet electronic chemicals by sub-boiling distillation method according to claim 2, characterized in that: The outlet of the primary circulation pump is connected in parallel with two pipelines, one of which is connected to the upper part of the primary falling film absorber, and the other is connected to the electronic grade hydrochloric acid filling system.

4. The device for preparing high-purity halide wet electronic chemicals by sub-boiling distillation method according to claim 1, characterized in that: The bottom of the secondary absorption tank is connected with a secondary circulation pump, and the outlet of the secondary circulation pump is connected to the upper part of the secondary falling film absorber.

5. The device for preparing high-purity halide wet electronic chemicals by sub-boiling distillation method according to claim 4, characterized in that: The outlet of the secondary circulation pump is connected in parallel with two pipelines, one of which is connected to the upper part of the secondary falling film absorber, and the other is connected to the primary absorption tank.

6. The device for preparing high-purity halide wet electronic chemicals by sub-boiling distillation method according to claim 1, characterized in that: The liquid outlet at the bottom of the absorption tower is connected to a cooler through a three-stage circulation pump, and the cooler is connected to a sprayer at the top of the absorption tower.

7. The device for preparing high-purity halide wet electronic chemicals by sub-boiling distillation method according to claim 6, characterized in that: The outlet of the three-stage circulation pump is connected in parallel with two pipelines, one of which is connected to the cooler and the other is connected to the secondary absorption tank.

8. The device for preparing high-purity halide wet electronic chemicals by sub-boiling distillation method according to claim 7, characterized in that: The top of the absorption tower is connected with a tail gas treatment device.

Images