Electronic grade HCl arsenic removal system and purification method

Abstract

The invention discloses an electronic grade HCl arsenic removal system and a purification method, the electronic grade HCl arsenic removal system comprises a raw material mixing system, a rectification purification system and a sulfuric acid gas washing system which are sequentially connected through pipelines, the raw material mixing system is used for mixing raw materials hydrochloric acid and a potassium permanganate solution, the rectification purification system is used for rectifying and purifying the mixed raw materials, and the sulfuric acid gas washing system is used for washing sulfuric acid. The sulfuric acid gas washing system is used for washing and removing moisture and metal impurities through concentrated sulfuric acid. The method comprises the following steps: mixing raw materials hydrochloric acid and a potassium permanganate solution through a raw material mixing system, enabling AsCl3 in the raw material hydrochloric acid to react to obtain AsCl5, carrying out rectification purification through a rectification purification system to remove AsCl5 and part of metal impurities, and washing through a sulfuric acid gas washing system to remove moisture and metal impurities so as to obtain an electronic grade HCl finished product.

Description

Technical Field

[0001] The invention relates to the technical field of electronic-grade HCl purification, and in particular to an electronic-grade HCl arsenic removal system and a purification method. Background Art

[0002] Electronic-grade HCl is a very important electronic gas in semiconductor technology, with a purity of over 99.999%. It is mainly used in the preparation of single-crystalline silicon, semiconductors, optoelectronics, photovoltaics, flat-panel displays and other electronic industries. Electronic-grade HCl can make the purity of crystalline silicon reach PPB level. In the semiconductor industry, electronic-grade HCl is also used in annealing, cleaning, etching and photolithography steps. Electronic-grade HCl is also needed in the manufacture of portable X-ray fluorescence instruments, high-definition imagers and other equipment.

[0003] At present, the main production process of electronic-grade HCl is the hydrochloric acid distillation process. Industrial-grade hydrochloric acid is distilled to obtain electronic-grade HCl. Most impurities in industrial-grade hydrochloric acid can be removed by distillation because their boiling points are much different from those of aqueous hydrochloric acid. The As content is an important indicator of electronic-grade HCl. Arsenic generally exists in hydrochloric acid in the form of AsCl3 and AsCl5. AsCl3 is difficult to separate in the distillation process because its boiling point is close to that of hydrochloric acid. This also leads to a high As content in the HCl product. For this reason, we proposed an electronic-grade HCl arsenic removal system and purification method.

[0004] In the prior art, Chinese patent document CN112723312A, published (announcement) date: 2021.04.30, discloses a method for purifying hydrogen chloride with low-concentration impure dilute hydrochloric acid. The document adopts different purification processes according to the composition and boiling point range of impurities in the dilute hydrochloric acid for purification. However, since the boiling point of AsCl3 is close to that of hydrochloric acid, this process cannot remove AsCl3 from industrial-grade hydrochloric acid.

[0005] In addition, Chinese patent document CN117585644A, published (announcement) date: 2024.02.23, discloses a method for preparing electronic grade hydrochloric acid, which uses a reducing agent to reduce free chlorine to chloride ions, improve the purity of hydrochloric acid, and reduce the content of arsenic, metal ions and other impurities. However, in this document, a metal filter membrane is used to reduce arsenic and metal ions from entering the condensation step with gaseous hydrogen chloride. The gap is nanometer-level. After a period of use, there will be a problem of metal filter membrane clogging, which affects filtration, and also requires shutdown and replacement, affecting production. Summary of the invention

[0006] In order to solve the current technical problems, the main purpose of the present invention is to provide an electronic-grade HCl arsenic removal system and purification method, wherein raw hydrochloric acid and potassium permanganate solution are mixed through a raw material mixing system to react AsCl3 in the raw hydrochloric acid into AsCl5, and then distilled and purified through a distillation purification system to remove AsCl5 and part of metal impurities, and then washed through a sulfuric acid washing system to remove moisture and metal impurities, thereby obtaining an electronic-grade HCl product.

[0007] In order to overcome the problems existing in the prior art, the technical solution adopted by the present invention is: an electronic grade HCl arsenic removal system, comprising a raw material mixing system, a distillation and purification system and a sulfuric acid scrubbing system connected in sequence through pipelines, the raw material mixing system is used to mix raw hydrochloric acid and potassium permanganate solution, the distillation and purification system is used to distill and purify the mixed raw materials to remove AsCl5 and some metal impurities, and the sulfuric acid scrubbing system is used to remove moisture and metal impurities by washing with concentrated sulfuric acid.

[0008] The raw material mixing system comprises a raw material mixing tank, which is provided with a raw material hydrochloric acid inlet and a potassium permanganate solution inlet, and the outlet end of the raw material mixing tank is connected with the distillation purification system through a pipeline.

[0009] The raw hydrochloric acid inlet and the potassium permanganate solution inlet are respectively equipped with a raw hydrochloric acid flow meter and a potassium permanganate solution flow meter.

[0010] A first circulation pipeline is also installed on the raw material mixing tank, one end of the first circulation pipeline is connected to the outlet end of the raw material mixing tank, and the other end is also connected to the raw material mixing tank, and a raw material mixing pump is installed on the first circulation pipeline; the first circulation pipeline is connected to the distillation and purification system through a pipeline at the outlet end of the raw material mixing pump; a raw material flow meter and a valve are installed on the pipeline connecting the first circulation pipeline and the distillation and purification system, and a valve is installed at the downstream end of the first circulation pipeline.

[0011] The distillation and purification system includes a distillation tower and a hydrochloric acid demister. The raw material mixing system is connected to the inlet end of the distillation tower of the distillation and purification system through a pipeline, the upper end of the distillation tower is connected to the inlet end of the hydrochloric acid demister through a pipeline, and the outlet end of the hydrochloric acid demister is connected to the sulfuric acid scrubbing system through a pipeline.

[0012] The distillation and purification system also includes a waste acid tank. The lower end of the distillation tower is connected to the waste acid tank through a pipeline. A valve is installed on the pipeline connecting the distillation tower and the waste acid tank.

[0013] The hydrochloric acid demister is connected with a first reflux pipeline, the first reflux pipeline is communicated with the distillation tower, and a valve is installed on the first reflux pipeline.

[0014] The sulfuric acid scrubbing system comprises a sulfuric acid scrubbing tower, a sulfuric acid storage tank, a sulfuric acid circulation pump and a sulfuric acid demister. The inlet end of the sulfuric acid scrubbing tower is connected to the distillation purification system through a pipeline, the upper end of the sulfuric acid scrubbing tower is connected to the inlet end of the sulfuric acid demister through a pipeline, the outlet end of the sulfuric acid demister is used to output electronic grade HCl finished product, the lower end of the sulfuric acid scrubbing tower is connected to the sulfuric acid storage tank through a pipeline, the sulfuric acid storage tank is also connected to the upper end of the sulfuric acid scrubbing tower through a second circulation pipeline, and the sulfuric acid circulation pump is installed on the second circulation pipeline.

[0015] The sulfuric acid demister is connected with a second reflux pipeline, the second reflux pipeline is communicated with the sulfuric acid scrubbing tower, and a valve is installed on the second reflux pipeline.

[0016] A method for purifying electronic-grade HCl, using the electronic-grade HCl arsenic removal system, the method comprising the following steps: S1, adding industrial hydrochloric acid and potassium permanganate solution into a raw material mixing system for mixing, so as to react AsCl3 in the industrial hydrochloric acid into AsCl5; S2. The raw materials mixed in the raw material mixing system are transported to the distillation and purification system through pipelines for distillation and purification to remove AsCl5 and some metal impurities; S3, the HCl gas purified by distillation is then passed through a distillation purification system to remove hydrochloric acid mist and metal impurities dissolved therein, and then enters a sulfuric acid scrubbing system; S4, HCl gas is washed with electronic grade sulfuric acid in the sulfuric acid washing system to remove a certain proportion of water and metal impurities dissolved therein; S5 and HCl gas then pass through the sulfuric acid scrubbing system to remove sulfuric acid mist, and finally obtain electronic grade HCl finished product.

[0017] The present invention has the following beneficial effects: The present invention mixes raw hydrochloric acid and potassium permanganate solution through a raw material mixing system to react low-boiling-point AsCl3 in the raw hydrochloric acid into high-boiling-point AsCl5, then performs rectification and purification through a rectification and purification system to remove AsCl5 and part of metal impurities, and then performs washing through a sulfuric acid washing system to remove water and metal impurities, thereby obtaining an electronic-grade HCl product. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1The present invention is a schematic structural diagram of an electronic-grade HCl arsenic removal system.

[0020] Reference numerals: Raw hydrochloric acid inlet 1, raw hydrochloric acid flowmeter 2, potassium permanganate solution inlet 3, potassium permanganate solution flowmeter 4, raw material mixing tank 5, raw material mixing pump 6, raw material flowmeter 7, distillation tower 8, waste acid tank 9, hydrochloric acid demister 10, sulfuric acid scrubbing tower 11, acid inlet 12, sulfuric acid storage tank 13, sampling port 14, sulfuric acid circulation pump 15, sulfuric acid demister 16, electronic grade HCl finished product 17. DETAILED DESCRIPTION

[0021] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] Embodiment 1: See also Figure 1 The present invention provides an electronic-grade HCl arsenic removal system, comprising a raw material mixing system, a distillation and purification system, and a sulfuric acid scrubbing system connected in sequence through pipelines, wherein the raw material mixing system is used to mix raw hydrochloric acid and potassium permanganate solution, the distillation and purification system is used to distill and purify the mixed raw materials to remove AsCl5 and some metal impurities, and the sulfuric acid scrubbing system is used to remove moisture and metal impurities by washing with concentrated sulfuric acid. The present invention mixes the raw hydrochloric acid and potassium permanganate solution through the raw material mixing system, so that AsCl3 in the raw hydrochloric acid reacts to AsCl5, and then distills and purifies through the distillation and purification system to remove AsCl5 and some metal impurities, and then washes through the sulfuric acid scrubbing system to remove moisture and metal impurities, thereby obtaining an electronic-grade HCl finished product.

[0023] In this embodiment, the raw material mixing system includes a raw material mixing tank 5, which is provided with a raw material hydrochloric acid inlet 1 and a potassium permanganate solution inlet 3, and the outlet end of the raw material mixing tank 5 is connected to the distillation purification system through a pipeline. The raw material hydrochloric acid inlet 1 is used to inject industrial hydrochloric acid into the raw material mixing tank 5, and the potassium permanganate solution inlet 3 is used to inject potassium permanganate solution into the raw material mixing tank 5. The industrial hydrochloric acid and the potassium permanganate solution are mixed in the raw material mixing tank 5, so that the low-boiling point AsCl3 in the industrial hydrochloric acid is fully reacted into the high-boiling point AsCl5, so that the impurity As and HCl are efficiently separated in the subsequent process.

[0024] Furthermore, a raw hydrochloric acid flowmeter 2 and a potassium permanganate solution flowmeter 4 are installed on the raw hydrochloric acid inlet 1 and the potassium permanganate solution inlet 3, respectively, to facilitate metering when industrial hydrochloric acid and potassium permanganate solution are respectively injected into the raw material mixing tank 5. In actual application, the raw hydrochloric acid flowmeter 2 and the potassium permanganate solution flowmeter 4 are interlocked with the control valves on the raw hydrochloric acid inlet 1 and the potassium permanganate solution inlet 3, respectively, to ensure the feed ratio of the raw hydrochloric acid inlet 1 and the potassium permanganate solution inlet 3.

[0025] In this embodiment, the distillation and purification system includes a distillation tower 8 and a hydrochloric acid demister 10. The raw material mixing system is connected to the inlet end of the distillation tower 8 of the distillation and purification system through a pipeline, the upper end of the distillation tower 8 is connected to the inlet end of the hydrochloric acid demister 10 through a pipeline, and the outlet end of the hydrochloric acid demister 10 is connected to the sulfuric acid washing system through a pipeline.

[0026] Specifically, the outlet of the raw material mixing tank 5 is connected to the inlet of the distillation tower 8 through a pipeline, and a valve is installed on the pipeline. After the industrial hydrochloric acid and potassium permanganate solution in the raw material mixing tank 5 are fully mixed and reacted, the valve is opened to allow the solution in the raw material mixing tank 5 to enter the distillation tower 8. The lower part of the distillation tower 8 is a shell and tube heat exchanger, and the upper part is a mesh corrugated structured packing, and the packing material is high-purity PTFE. When in use, the solution is heated and evaporated by the distillation tower 8, and AsCl5 will not be evaporated due to its high boiling point, and the HCl gas passes upward through the hydrochloric acid demister 10 to remove most of the hydrochloric acid mist and metal impurities dissolved therein.

[0027] Furthermore, a first reflux pipeline is connected to the hydrochloric acid demister 10, and the first reflux pipeline is communicated with the distillation tower 8, and a valve is installed on the first reflux pipeline. Through the above structure, the hydrochloric acid in the hydrochloric acid demister 10 can flow back into the distillation tower 8 through the first reflux pipeline.

[0028] In this embodiment, the sulfuric acid scrubbing system includes a sulfuric acid scrubbing tower 11, a sulfuric acid storage tank 13, a sulfuric acid circulation pump 15 and a sulfuric acid demister 16. The inlet end of the sulfuric acid scrubbing tower 11 is connected to the distillation purification system through a pipeline, the upper end of the sulfuric acid scrubbing tower 11 is connected to the inlet end of the sulfuric acid demister 16 through a pipeline, and the outlet end of the sulfuric acid demister 16 outputs an electronic grade HCl product 17. The lower end of the sulfuric acid scrubbing tower 11 is connected to the sulfuric acid storage tank 13 through a pipeline, and the sulfuric acid storage tank 13 is also connected to the upper end of the sulfuric acid scrubbing tower 11 through a second circulation pipeline, and the sulfuric acid circulation pump 15 is installed on the second circulation pipeline.

[0029] Specifically, the outlet end of the hydrochloric acid demister 10 is connected to the inlet end of the sulfuric acid scrubbing tower 11 through a pipeline. The HCl after passing through the hydrochloric acid demister 10 continues to enter the sulfuric acid scrubbing tower 11 backward. The HCl flows upward in the tower, and the concentrated sulfuric acid flows downward in the tower to further absorb water vapor and metal impurities in the HCl. After the sulfuric acid mist is removed by the sulfuric acid demister 16, the HCl becomes an electronic grade HCl product 17.

[0030] The sulfuric acid storage tank 13 is used to store electronic grade sulfuric acid. The sulfuric acid in the sulfuric acid storage tank 13 needs to be sampled and tested for concentration regularly through the sampling port 14. When the sulfuric acid concentration is lower than a threshold value or the metal ion content is higher than a threshold value, the vehicle needs to be stopped to drain it through the sampling port 14, and then electronic grade sulfuric acid is re-added through the acid inlet 12.

[0031] Embodiment 2: On the basis of Example 1, a first circulation pipeline is further installed on the raw material mixing tank 5, one end of the first circulation pipeline is connected to the outlet end of the raw material mixing tank 5, and the other end is also connected to the raw material mixing tank 5, and a raw material mixing pump 6 is installed on the first circulation pipeline; the outlet end of the first circulation pipeline located at the raw material mixing pump 6 is connected to the distillation purification system through a pipeline; a raw material flow meter 7 and a valve are installed on the pipeline connecting the first circulation pipeline and the distillation purification system, and a valve is installed at the downstream end of the first circulation pipeline. Through the first circulation pipeline and the raw material mixing pump 6, when the valve on the pipeline connecting the first circulation pipeline and the distillation purification system is closed, the raw material mixing pump 6 is opened to circulate the solution in the raw material mixing tank 5, so that the two solutions are fully reacted.

[0032] Embodiment 3: On the basis of Example 1 or 2, the distillation purification system further includes a waste acid tank 9, the lower end of the distillation tower 8 is connected to the waste acid tank 9 through a pipeline, and a valve is installed on the pipeline connecting the distillation tower 8 and the waste acid tank 9. When hydrochloric acid remains at the bottom of the distillation tower 8, the valve is opened to allow the waste acid to flow downward into the waste acid tank 9.

[0033] Embodiment 4: On the basis of embodiment 1 or 2 or 3, the sulfuric acid demister 16 is connected with a second reflux pipe, the second reflux pipe is communicated with the sulfuric acid scrubber 11, and a valve is installed on the second reflux pipe. Through the above structure, the sulfuric acid in the sulfuric acid demister 16 can flow back into the sulfuric acid scrubber 11 through the second reflux pipe.

[0034] Embodiment 5: See also Figure 1 A method for purifying electronic grade HCl using an electronic grade HCl arsenic removal system comprises the following steps: Before the system is put into operation, a 0.5% KMnO4 solution is required. The selected potassium permanganate is analytically pure, and the water used is ultrapure water with an ion conductivity below 18 MΩ*cm. Electronic grade sulfuric acid with a concentration of 96% and metal ions below 10ppt is pumped into the sulfuric acid storage tank 13 through the acid inlet 12. When the liquid level in the sulfuric acid storage tank 13 reaches 2 / 3, the addition is stopped, and then the sulfuric acid circulation pump 15 is turned on for internal circulation.

[0035] S1. Add industrial hydrochloric acid and potassium permanganate solution into a raw material mixing system for mixing, so as to react AsCl3 in the industrial hydrochloric acid into AsCl5.

[0036] Specifically, the prepared potassium permanganate solution is pumped into the raw material mixing tank 5 through the potassium permanganate solution inlet 3, and the flow rate is controlled by the potassium permanganate solution flow meter 4 and the front regulating valve. Industrial hydrochloric acid is pumped into the raw material mixing tank 5 through the raw hydrochloric acid inlet 1, and the flow rate is controlled by the raw hydrochloric acid flow meter 2 and the front regulating valve, and the flow ratio of potassium permanganate solution to industrial hydrochloric acid is maintained between 1:100 and 1:50. When a certain liquid level is established in the raw material mixing tank 5, the raw material mixing pump 6 is turned on to fully mix the two solutions, so that the low-boiling point AsCl3 is fully reacted to become the high-boiling point AsCl5.

[0037] S2. The mixed raw materials in the raw material mixing system are transported through pipelines to the distillation and purification system for distillation and purification to remove AsCl5 and some metal impurities.

[0038] Specifically, when the liquid level of the raw material mixing tank 5 is at 2 / 3, the regulating valve in front of the raw material flowmeter 7 is opened to control its flow rate to be the sum of the raw material hydrochloric acid flowmeter 2 and the potassium permanganate solution flowmeter 4, and then the steam valve of the distillation tower 8 is opened to maintain the tower top temperature between 100 and 110°C. The hydrochloric acid is evaporated after heating, and AsCl5 will not be evaporated due to its high boiling point, thereby removing AsCl5 and some metal impurities.

[0039] S3, the HCl gas purified by distillation passes through the distillation purification system to remove the hydrochloric acid mist and the metal impurities dissolved therein, and then enters the sulfuric acid scrubbing system.

[0040] Specifically, the HCl gas after distillation and purification passes upward through the hydrochloric acid demister 10 to remove most of the hydrochloric acid mist and the metal impurities dissolved therein, and then enters the sulfuric acid scrubbing tower 11.

[0041] S4, HCl gas is washed with electronic grade sulfuric acid in the sulfuric acid washing system to remove a certain proportion of water and metal impurities dissolved therein; After passing through the hydrochloric acid demister 10, the HCl continues to flow backward into the sulfuric acid scrubbing tower 11, where the HCl flows upward and the concentrated sulfuric acid flows downward to further absorb the water vapor and metal impurities in the HCl.

[0042] S5 and HCl gas are then passed through a sulfuric acid scrubbing system to remove sulfuric acid mist, and finally electronic grade HCl product 17 is obtained.

[0043] The HCl gas flows out from the top of the sulfuric acid scrubbing tower 11 and passes through the sulfuric acid demister 16 to remove the sulfuric acid mist brought out, and finally obtains pure HCl.

[0044] When the system is running, the sulfuric acid in the sulfuric acid storage tank 13 needs to be sampled regularly through the sampling port 14 for concentration testing. When the sulfuric acid concentration is lower than 80% or the metal ion content is higher than 100ppt, it is necessary to stop the system to drain it through the sampling port 14, and then re-add electronic grade sulfuric acid with a concentration of 96% and metal ions less than 10ppt through the acid inlet 12.

[0045] The technical solution of the present invention is explained through the above embodiments, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above specific embodiments to be implemented. Any improvements made by technicians in the relevant field on the basis of the present invention, or equivalent replacement of materials selected by the present invention, etc., fall within the protection scope of this patent.

Claims

1. An electronic grade HCl arsenic removal system, characterized by: The invention comprises a raw material mixing system, a distillation and purification system and a sulfuric acid scrubbing system which are sequentially connected by pipelines. The raw material mixing system is used to mix raw hydrochloric acid and potassium permanganate solution. The distillation and purification system is used to distill and purify the mixed raw materials to remove AsCl5 and some metal impurities. The sulfuric acid scrubbing system is used to remove moisture and metal impurities by washing with concentrated sulfuric acid.

2. An electronic grade HCl arsenic removal system according to claim 1, characterized in that: The raw material mixing system comprises a raw material mixing tank (5), the raw material mixing tank (5) is provided with a raw material hydrochloric acid inlet (1) and a potassium permanganate solution inlet (3), and the outlet end of the raw material mixing tank (5) is connected to the distillation purification system through a pipeline.

3. An electronic grade HCl arsenic removal system according to claim 2, characterized in that: The raw hydrochloric acid inlet (1) and the potassium permanganate solution inlet (3) are respectively equipped with a raw hydrochloric acid flow meter (2) and a potassium permanganate solution flow meter (4).

4. An electronic grade HCl arsenic removal system according to claim 2 or 3, characterized in that: The raw material mixing tank (5) is also provided with a first circulation pipeline, one end of which is connected to the outlet end of the raw material mixing tank (5), and the other end of which is also in communication with the raw material mixing tank (5), and a raw material mixing pump (6) is installed on the first circulation pipeline; the outlet end of the raw material mixing pump (6) on the first circulation pipeline is connected to the distillation purification system through a pipeline; a raw material flow meter (7) and a valve are installed on the pipeline connecting the first circulation pipeline and the distillation purification system, and a valve is installed at the downstream end of the first circulation pipeline.

5. The electronic grade HCl arsenic removal system according to claim 1, characterized in that: The distillation and purification system comprises a distillation tower (8) and a hydrochloric acid demister (10); the raw material mixing system is connected to the inlet end of the distillation tower (8) of the distillation and purification system through a pipeline; the upper end of the distillation tower (8) is connected to the inlet end of the hydrochloric acid demister (10) through a pipeline; and the outlet end of the hydrochloric acid demister (10) is connected to the sulfuric acid scrubbing system through a pipeline.

6. The electronic grade HCl arsenic removal system according to claim 5, characterized in that: The distillation and purification system further comprises a waste acid tank (9), the lower end of the distillation tower (8) is connected to the waste acid tank (9) via a pipeline, and a valve is installed on the pipeline connecting the distillation tower (8) and the waste acid tank (9).

7. The electronic grade HCl arsenic removal system according to claim 5, characterized in that: The hydrochloric acid demister (10) is connected to a first reflux pipeline, the first reflux pipeline is in communication with the distillation tower (8), and a valve is installed on the first reflux pipeline.

8. The electronic grade HCl arsenic removal system according to claim 1, characterized in that: The sulfuric acid scrubbing system comprises a sulfuric acid scrubbing tower (11), a sulfuric acid storage tank (13), a sulfuric acid circulation pump (15) and a sulfuric acid demister (16). The inlet end of the sulfuric acid scrubbing tower (11) is connected to the distillation purification system through a pipeline. The upper end of the sulfuric acid scrubbing tower (11) is connected to the inlet end of the sulfuric acid demister (16) through a pipeline. The outlet end of the sulfuric acid demister (16) is used to output electronic grade HCl finished product (17). The lower end of the sulfuric acid scrubbing tower (11) is connected to the sulfuric acid storage tank (13) through a pipeline. The sulfuric acid storage tank (13) is also connected to the upper end of the sulfuric acid scrubbing tower (11) through a second circulation pipeline. The sulfuric acid circulation pump (15) is installed on the second circulation pipeline.

9. The electronic grade HCl arsenic removal system according to claim 8, characterized in that: The sulfuric acid demister (16) is connected to a second reflux pipeline, the second reflux pipeline is in communication with the sulfuric acid scrubbing tower (11), and a valve is installed on the second reflux pipeline.

10. A method for purifying electronic grade HCl, characterized in that: An electronic grade HCl arsenic removal system according to any one of claims 1 to 9 is used, and the method comprises the following steps: S1, adding industrial hydrochloric acid and potassium permanganate solution into a raw material mixing system for mixing, so as to react AsCl3 in the industrial hydrochloric acid into AsCl5; S2. The raw materials mixed in the raw material mixing system are transported to the distillation and purification system through pipelines for distillation and purification to remove AsCl5 and some metal impurities; S3, the HCl gas purified by distillation is then passed through a distillation purification system to remove hydrochloric acid mist and metal impurities dissolved therein, and then enters a sulfuric acid scrubbing system; S4, HCl gas is washed with electronic grade sulfuric acid in the sulfuric acid washing system to remove a certain proportion of water and metal impurities dissolved therein; S5 and HCl gas are then passed through a sulfuric acid scrubbing system to remove sulfuric acid mist, and finally electronic grade HCl product (17) is obtained.

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