Device for continuously removing arsenic from anhydrous hydrogen fluoride

Abstract

The utility model discloses a continuous arsenic removal device for anhydrous hydrogen fluoride, which is characterized in that a product tank is connected with a primary rectifying tower, the primary rectifying tower is in pipeline connection with a heat exchanger, the heat exchanger is respectively in pipeline connection with a first finished product tank, a second finished product tank and a third finished product tank, and the first finished product tank, the second finished product tank and the third finished product tank are respectively connected with a secondary rectifying tower; and the secondary rectifying tower is connected with the product tank. According to the utility model, the first finished product tank, the second finished product tank and the third finished product tank are connected with the existing rectifying tower by adding corresponding pipelines at the outlet of the circulating submerged pump for real-time switching use of arsenic removal oxidation, acid feeding and acid discharging, so that continuous arsenic removal production is realized, and the influence on normal production of the device is avoided.

Description

Technical Field

[0001] The utility model belongs to the technical field of hydrogen fluoride preparation, and particularly relates to a device for continuously removing arsenic from anhydrous hydrogen fluoride. Background Technique

[0002] Hydrogen fluoride is mainly used in processes such as cleaning and etching in the semiconductor manufacturing process. Therefore, its purity and cleanliness have a very important impact on the yield, electrical performance, and reliability of integrated circuits. For example, in the process of manufacturing ultra-large-scale integrated circuits, the quality standard of the electronic-grade hydrofluoric acid used should reach the semiconductor equipment and materials international standard SEMI-2 standard – 9 standard (European standard ULSI level). This standard requires that the mass fraction of impurities in hydrofluoric acid be at the 10 level (ppb), and the content of arsenic impurities is less than 15 ppb.

[0003] Arsenic itself is a doping element when forming the semiconductor P-N junction. Therefore, when using hydrofluoric acid containing arsenic for semiconductor integrated circuit cleaning or etching, it will have a greater impact on the yield and electrical performance of semiconductor integrated circuits. In addition, hydrogen fluoride can also be used in petroleum refining and chemical preparation, but the arsenic element contained in hydrogen fluoride will cause the reaction catalyst to be poisoned, reducing or losing its activity and affecting the continuation of the catalytic reaction. Therefore, it is necessary to remove the arsenic element in hydrogen fluoride.

[0004] Chinese Patent CN115611238A discloses a continuous reaction process and system for removing arsenic from anhydrous hydrogen fluoride. The process includes an oxidation process, a light component removal process, and a heavy component removal process. Cyclic fluorine gas is used to oxidize trivalent arsenic ions, sulfur dioxide, and other low-boiling-point and easily oxidizable substances in industrial-grade hydrogen fluoride into high-boiling-point substances, and light component impurities, heavy component impurities, and metal impurities are removed through the light component removal process and the heavy component removal process to obtain an anhydrous hydrogen fluoride product with an arsenic ion content lower than 0.2 (ppb).

[0005] Chinese Patent CN101597032A discloses a preparation method of electronic-grade high-purity hydrofluoric acid. By adding potassium permanganate aqueous solution and sodium hydroxide aqueous solution to anhydrous hydrogen fluoride, and then removing metal ions through rectification, high-polymer high-total adsorption, a mixed-bed cation-anion system, and ultrafiltration, electronic-grade high-purity hydrofluoric acid is obtained. It avoids the cumbersome process of anhydrous hydrogen fluoride absorbing hydrofluoric acid and then rectifying, and directly uses anhydrous hydrogen fluoride liquid for rectification and purification; it can effectively remove inorganic species impurities such as arsenic trifluoride, SO2, SO3, and H2SiF6; it can deeply remove various metal impurities and solid particles, and purify and refine industrial-grade hydrofluoric acid to obtain an ultra-high-purity hydrofluoric acid reagent that meets the SIME-C8 standard, making the product meet the quality of ultra-clean electronic-grade hydrofluoric acid and suitable for ultra-precision integrated circuit production.

[0006] However, the industrial application of the technology for producing anhydrous hydrogen fluoride from fluosilicic acid has a narrow scope, and the processes are similar to each other, all of which cannot economically and effectively remove arsenic in the product. In addition, in the existing technology, high-purity sewage hydrogen fluoride can only be produced in batches, and continuous production cannot be achieved. Therefore, it is necessary to design a production device that can continuously produce high-quality anhydrous hydrogen fluoride. Summary of the Invention

[0007] In view of the above technical problems, the utility model provides a device for continuous arsenic removal of anhydrous hydrogen fluoride, which realizes the implementation switch of continuous production of high-purity anhydrous hydrogen fluoride without affecting the normal production of the device.

[0008] To achieve the above object, the utility model provides a device for continuous arsenic removal of anhydrous hydrogen fluoride. The product tank is connected to the first-stage rectification column, the first-stage rectification column is connected to the heat exchanger pipeline, the heat exchanger is respectively connected to the pipelines of the first finished product tank, the second finished product tank and the third finished product tank, the first finished product tank, the second finished product tank and the third finished product tank are respectively connected to the second-stage rectification column, and the second-stage rectification column is connected to the product tank.

[0009] Preferably, the product tank is connected to the heat exchanger pipeline, and a first submerged pump is provided on the pipeline.

[0010] Preferably, a cut-off valve is provided on the pipeline connecting the first-stage rectification column and the heat exchanger.

[0011] Preferably, regulating valves are provided on the pipelines connecting the heat exchanger with the first finished product tank, the second finished product tank and the third finished product tank.

[0012] Preferably, a second submerged pump is provided on the inlet pipeline of the first finished product tank, a third submerged pump is provided on the inlet pipeline of the second finished product tank, and a fourth submerged pump is provided on the inlet pipeline of the third finished product tank.

[0013] Preferably, the heat exchanger is connected to the chilled water storage tank in a circulating manner.

[0014] More preferably, the chilled water storage tank is respectively connected to the first finished product tank, the second finished product tank and the third finished product tank in a circulating manner.

[0015] The beneficial effect of the utility model is that the first finished product tank, the second finished product tank and the third finished product tank are connected to the existing rectification column through adding corresponding pipelines at the outlet of the circulating submerged pump for arsenic removal oxidation, acid inlet and acid outlet real-time switching use, so as to realize continuous arsenic removal production and avoid affecting the normal production of the device. Brief Description of the Drawings

[0016] Figure 1This is the overall structural schematic diagram of the present utility model. In the figure, 1 is the product tank, 2 is the heat exchanger, 3 is the primary rectification column, 4 is the secondary rectification column, 5 is the first finished product tank, 6 is the second finished product tank, 7 is the third finished product tank, 8 is the chilled water storage tank, 9 is the first submersible pump, 10 is the second submersible pump, 11 is the third submersible pump, 12 is the fourth submersible pump, 13 is the regulating valve, 14 is the cut-off valve, and 15 is the product tank. Detailed implementation manners

[0017] The technical solution of the present utility model will be further explained and illustrated below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the following embodiments are only the preferred embodiments of the present utility model and should not be construed as limitations on the present utility model. The protection scope of the present utility model shall be subject to the content recorded in the claims. Any modifications and substitutions made by those skilled in the art to the technical solution of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0018] Embodiment 1

[0019] As Figure 1 shown, a device for continuous arsenic removal of anhydrous hydrogen fluoride, the product tank 1 is connected to the primary rectification column 3, and the primary rectification column 3 is connected to the heat exchanger 2 through a pipeline to perform preliminary rectification and heat exchange cooling on the hydrogen fluoride product; the heat exchanger 2 is respectively connected to the first finished product tank 5, the second finished product tank 6 and the third finished product tank 7 through pipelines to perform three-stage arsenic removal on the cooled hydrogen fluoride product; the first finished product tank 5, the second finished product tank 6 and the third finished product tank 7 are respectively connected to the secondary rectification column 4, and the secondary rectification column 4 is connected to the product tank 15 to perform secondary rectification on the arsenic-removed hydrogen fluoride product, and then obtain the arsenic-removed anhydrous hydrogen fluoride product, which is stored in the product tank 15.

[0020] Preferably, the product tank 1 is connected to the heat exchanger 2 through a pipeline, and the first submersible pump 9 is provided on the pipeline.

[0021] Preferably, a cut-off valve 14 is provided on the pipeline connecting the primary rectification column 3 and the heat exchanger 2 to control whether the hydrogen fluoride product enters the heat exchanger 2, and it can be selected whether to perform preliminary rectification on the hydrogen fluoride product.

[0022] Preferably, a regulating valve 13 is provided on the pipeline connecting the heat exchanger 2 to the first finished product tank 5, the second finished product tank 6 and the third finished product tank 7 to adjust the passing amount of the hydrogen fluoride product and keep the hydrogen fluoride product in the finished product tank at an appropriate level.

[0023] Preferably, a second submerged pump 10 is provided on the inlet pipeline of the first finished product tank 5, a third submerged pump 11 is provided on the inlet pipeline of the second finished product tank 6, and a fourth submerged pump 12 is provided on the inlet pipeline of the third finished product tank 7. The second submerged pump 10, the third submerged pump 11, and the fourth submerged pump 12 are respectively connected to the first-stage rectification tower 3 via pipelines and are used for real-time switching of dearsenification oxidation, acid inlet, and acid outlet, so as to achieve continuous production.

[0024] Preferably, the heat exchanger 2 is connected in a cycle with the chilled water storage tank 8 to continuously supply chilled water to the heat exchanger 2 to cool the hydrogen fluoride product.

[0025] More preferably, the chilled water storage tank 8 is respectively connected in a cycle with the first finished product tank 5, the second finished product tank 6, and the third finished product tank 7 to cool the hydrogen fluoride product.

Claims

1. An apparatus for continuous arsenic removal from anhydrous hydrogen fluoride, characterized in that: The product tank (1) is connected to the primary distillation column (3), the primary distillation column (3) is connected to the heat exchanger (2) through pipelines, the heat exchanger (2) is respectively connected to the first finished product tank (5), the second finished product tank (6) and the third finished product tank (7) through pipelines, the first finished product tank (5), the second finished product tank (6) and the third finished product tank (7) are respectively connected to the secondary distillation column (4), and the secondary distillation column (4) is connected to the product tank (15).

2. The device for continuous arsenic removal from anhydrous hydrogen fluoride according to claim 1, characterized in that: The product tank (1) is connected to the heat exchanger (2) through pipelines, and a first submersible pump (9) is provided on the pipeline.

3. The device for continuous arsenic removal from anhydrous hydrogen fluoride according to claim 1, wherein: A cut-off valve (14) is provided on the pipeline connecting the primary distillation column (3) and the heat exchanger (2).

4. The device for continuous arsenic removal from anhydrous hydrogen fluoride according to claim 1, characterized in that: A regulating valve (13) is provided on the pipeline connecting the heat exchanger (2) with the first finished product tank (5), the second finished product tank (6) and the third finished product tank (7).

5. The device for continuous arsenic removal from anhydrous hydrogen fluoride according to claim 1, characterized in that: A second submersible pump (10) is provided on the inlet pipeline of the first finished product tank (5), a third submersible pump (11) is provided on the inlet pipeline of the second finished product tank (6), and a fourth submersible pump (12) is provided on the inlet pipeline of the third finished product tank (7).

6. The device for continuous arsenic removal from anhydrous hydrogen fluoride according to claim 1, characterized in that: The heat exchanger (2) is connected in a cycle with the chilled water storage tank (8).

7. The device for continuous arsenic removal from anhydrous hydrogen fluoride according to claim 6, characterized in that: The chilled water storage tank (8) is respectively connected in a cycle with the first finished product tank (5), the second finished product tank (6) and the third finished product tank (7).

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