KR102256840B1 - Elimination and treatment method of Arsenic compound in hydrogen fluoride for manufacturing of ultra-high-purity hydrogen fluoride - Google Patents

Abstract

The present invention relates to an elimination and treatment method of an arsenic compound in hydrogen fluoride during manufacture of ultra-high-purity hydrogen fluoride, which comprises: a first step of introducing natural-hydrofluoric acid (crude-AHF) containing AsF_3 and F_2 gas as an oxidizing agent into a reactor; a second step of producing AsF_5 gas by an oxidation reaction of the AsF_ 3 and F_2 gas; a third step of forming an XAsF_x(OH)_y compound (X is one selected from Na, K, Li, Ca, and Ba, x is 5-7 and y is 0 or 1) by reacting the produced AsF_5 gas with an absorption liquid; and a fourth step of discharging the AsF_5 gas that did not react with the absorption liquid in the third step to the atmosphere. According to the present invention, by using a method of maximizing a contact time to increase a conversion rate during oxidation of AsF_3 using F_2 gas, the arsenic compound in the hydrogen fluoride can be removed with high efficiency when producing the ultra-high-purity hydrogen fluoride, and a gaseous arsenic compound generated during a manufacturing process can be effectively treated.

Description

Elimination and treatment method of Arsenic compound in hydrogen fluoride for manufacturing of ultra-high-purity hydrogen fluoride}

The present invention relates to a method for removing and treating arsenic compounds in hydrogen fluoride during the production of ultra-high purity hydrogen fluoride, and in detail, in the production of ultra-high purity hydrogen fluoride for semiconductor etching, arsenic compounds in hydrogen fluoride are removed and gaseous phase released into the atmosphere. It relates to an effective treatment method of arsenic compounds.

Hydrogen Fluoride (HF), which is an industrial standard that manufactures glass cleaners and catalysts for petrochemicals, is not significantly restricted by the concentration of impurities. However, in the case of hydrogen fluoride used in semiconductor processes, metal impurities depending on the application. ) Ultra-high purity contracting with a content of 10 ppb or less is required.

In general, hydrogen fluoride used in semiconductor processes is used by purifying industrial standard hydrogen fluoride during manufacturing. Hydrogen fluoride, industrial standard, hydrofluoric acid 99.9%, SO ₂ 50ppm or less, H ₂ SiF ₆ 10ppm and _{out, H 2 SO 4 20 ~ 30ppm} , H 2 O 5 ~ 10ppm and the arsenic metal form, such as (As), iron (Fe) Contains a trace amount of impurities. Among them, SO ₂ , H ₂ SiF ₆ , H ₂ SO ₄ , H ₂ O and some metals can be removed by a known distillation method. However, in the case of the arsenic (As) compound remaining in hydrogen fluoride, it is difficult to separate it through a general distillation process.

Most of these arsenic compounds present in hydrogen fluoride exist in the _{form of AsF 3} (Arsenic Trifluoride; BP = 63℃), but they are separated by a distillation process because they form an azeotropic mixture in the presence of hydrogen fluoride (BP = 19.5℃). Is difficult.

For this reason, in order to produce hydrogen fluoride of ultra-high purity, it is a common method to remove arsenic compounds through processes such as adsorption and reaction. However, in the case of this method, when the arsenic compounds converted to other forms are exposed to the atmosphere, environmental pollution problems may be seriously generated. Currently, in Korea, the allowable emission concentration of arsenic compounds in the air is strictly managed at 0.5 ppm, so the emission concentration of arsenic compounds must be treated below the allowable emission concentration before being discharged into the atmosphere.

Looking at the prior art for the treatment of such arsenic compounds, Japanese Patent No. 2,821,947 uses _{KMnO 4} as a reaction accelerator to remove _{AsF 3} and converts it into an easy-to-separate AsOF ₃ form to reduce the concentration of arsenic compounds in hydrogen fluoride. It is reported that it is lowered, but it has not been able to provide information on the treatment of arsenic compounds.

In addition, looking at the example of Korean Patent Registration 10-1308051, F ₂ , KMnO ₄ , H ₂ O ₂ and the like, which are easy to react with arsenic compounds, are added and reacted with ultra-high-purity hydrofluoric acid at the time of tablet manufacturing, so that the reaction is sufficiently accelerated. It has been reported that the concentration of arsenic compounds in hydrofluoric acid is lowered by reacting while applying ultrasonic vibrations, but it has not been able to present any details on the treatment of arsenic compounds converted to _{AsOF 3 form.}

Japanese Patent No. 2,821,947 Korean Patent Registration 10-1308051

Accordingly, the present invention provides a method of removing arsenic compounds in hydrogen fluoride with high efficiency in manufacturing ultra-high purity grade hydrogen fluoride, and a method of treating gaseous arsenic compounds generated during the manufacturing process to an allowable emission concentration (0.5 ppm) or less. For that purpose.

The method for removing and treating arsenic compounds in hydrogen fluoride when producing ultra-high purity hydrogen fluoride gas according to the present invention is a first step of introducing natural-anhydrous hydrofluoric acid (Crude-AHF) including _{AsF 3 and F 2 gas as an oxidizing agent into the reactor.} the AsF ₃ and a second step of producing a AsF ₅ gas to the oxidation reaction of F ₂ gas, and the reacted by-produced AsF ₅ gas and absorbing liquid XAsF _x (OH) _y (X = Na, K, Li, Ca, It is selected from Ba; x = 5 to 7; y = 0 or 1) A third step of forming a compound, and a fourth step of discharging the _{AsF 5 gas that has not reacted with the absorbent in the third step to the atmosphere} It can be done by doing.

According to an embodiment of the present invention, the _{concentration of the arsenic compound (AsF 3} ) present in the Crude-AHF of the first step is preferably 0.5 to 1,000 ppm.

According to an embodiment of the present invention, the AsF ₃ and F ₂ gas of the first step are preferably introduced in a molar ratio of 1:5 to 100.

It is preferable that the oxidation reaction time of the second step is 4 to 36 hours.

The oxidation reaction _{of AsF 3} and F ₂ gas in the second step;

Ⅰ) The _{Crude-AHF containing the F 2} gas and AsF ₃ is first made by countercurrent contact in the column connected to the reactor, and at the same time, ii) it may be secondly made inside the reactor through the deep nozzle installed in the reactor. have.

In addition, the present invention is characterized in that the unreacted F ₂ gas not participating in the oxidation reaction of the second step is continuously circulated and reused without being discharged to the outside of the reactor.

_{The reaction of the AsF 5} gas and the absorbent liquid in the third step is performed in the absorption tower; The AsF ₅ gas is transported from the bottom of the absorption tower to the top, and the absorbent liquid is transferred from the top of the absorption tower to the bottom of the absorption tower, and makes countercurrent contact with each other.

It is preferable that the input rate of the AsF ₅ gas into the absorption tower is 100 to 5,000 ml/hr.

The absorption liquid is at least one member selected from the group consisting of NaOH, NaF, LiF, KOH, KF, CaF 2, and BaF _2, its concentration may be from 0.1 to 5% by weight.

There may be a plurality of absorption towers, and it is preferable to arrange them in series.

According to an embodiment of the present invention, the third step of XAsF _x (OH) _y (X = selected from Na, K, Li, Ca, Ba; x = 5 to 7; y = 0 or 1) compound Is in a liquid state, and is characterized by being discharged and removed as it is.

It is preferable that the concentration of the arsenic compound including the _{AsF 5} gas that has not reacted with the absorbent liquid in the fourth step is 0.5 ppm or less, which is an allowable emission concentration.

According to the present invention, by using _{a method of maximizing the contact time in order to increase the conversion rate when oxidizing AsF 3 using F 2} gas, it is possible to remove arsenic compounds in hydrogen fluoride with high efficiency when producing ultra-high purity hydrogen fluoride, It is possible to provide a method that can effectively treat gaseous arsenic compounds generated during the manufacturing process.

According to the method of the present invention, since a separate oxidation catalyst is not used, a process for regenerating it is not required, and a continuous reaction is possible by performing a reaction in a liquid phase in the arsenic compound removal process, so that an economical process can be operated compared to the existing method have. In addition, through such a method, it has the effect of controlling the concentration of arsenic compounds discharged to the gas phase to less than the allowable emission concentration of 0.5 ppm.

1 is a schematic diagram showing a treatment and removal method according to the present invention,
2 shows the concept of removing and treating arsenic compounds in hydrogen fluoride during production of ultra-high purity hydrogen fluoride gas according to the present invention.

Hereinafter, the present invention will be described in more detail.

The terms used in this specification are used to describe specific embodiments, and are not intended to limit the present invention.

As used herein, the singular form may include the plural form unless the context clearly indicates another case. In addition, when used herein, "comprise" and/or "comprising" refers to the presence of the mentioned shapes, numbers, steps, actions, members, elements, and/or groups thereof. And does not exclude the presence or addition of one or more other shapes, numbers, actions, members, elements and/or groups.

The present invention provides a method of removing arsenic compounds in hydrogen fluoride with high efficiency when producing ultra-high purity hydrogen fluoride and treating arsenic compounds in gaseous phase generated during the manufacturing process to an allowable emission concentration of 0.5 ppm or less.

“Ultra-high purity hydrogen fluoride” used in the present invention means having a purity of 99.9999% or more.

Natural that the method according to the invention comprises a AsF ₃ - anhydrous hydrofluoric acid (Crude-AHF, Crude-Anhydrous Hydrogen Fluoride) with the oxidation of the step, the AsF ₃ and F ₂ gas 1 to inject the oxidant F ₂ gas to the reactor a second step of producing a AsF ₅ gas to react, by reacting the above prepared AsF ₅ gas and the absorbing liquid is selected from the _{XAsF x (OH) y (x} = Na, K, Li, Ca, Ba; x = 5 ~ 7 ; y = 0 or 1) a third step of forming a compound, and _{a fourth step of discharging the AsF 5} gas that has not reacted with the absorbent in the third step to the atmosphere, and referring to FIGS. 1 and 2 It will be described in detail below.

1.Crude-AHF and F ₂ Gas input process

In this process, raw materials and reactants are added to convert _{hydrogen fluoride and AsF 3} , an azeotropic substance, into an easy-to-separate AsF _{5 form.}

1) Before introducing the natural-anhydrous hydrofluoric acid (Crude-AHF, Anhydrous Hydrogen Fluoride) and the oxidizing agent F ₂ gas, the heat source of the reactor 10 is removed and the cooling water of the heat exchanger 20 is circulated in advance.

2) Crude-AHF is supplied to the reactor 10 through line ①. _{The concentration of the arsenic compound (AsF 3} ) present in the supplied Crude-AHF is usually 1,000 ppm or less, preferably 100 ppm or less, and very preferably 10 ppm or less.

3) When Crude-AHF is supplied to the reactor 10, the oxidizing agent F ₂ gas is supplied to the reactor 10 through line ②. The ratio of the arsenic compound (AsF ₃ ) and the F ₂ gas to be introduced is preferably 1: 5 to 100 on a molar basis. If the molar ratio of the arsenic compound (AsF ₃ ) and the F ₂ gas to be introduced is less than 1:5, the conversion rate to the _{AsF 5 form is lowered, which is not preferable, and the mole of the arsenic compound (AsF 3} ) and the F ₂ gas to be introduced When the ratio exceeds 1:100, the synergistic effect of the conversion rate is insufficient.

2. AsF ₃ + F ₂ → AsF ₅ Oxidation process

This process converts hydrogen fluoride and AsF ₃ , an _{azeotropic substance, into AsF 5} form, which is easy to separate by oxidizing it using _{F 2 gas.}

1) When the injection of Crude-AHF and F ₂ gas is completed as described above, the F ₂ compressor 30 is operated to circulate the _{F 2 gas.} At this time, the F ₂ gas is bubbled and introduced through a dip nozzle 11 installed in the reactor 10. Here, the F ₂ gas is circulated from the bottom to the top in the order of the reactor 10 → column 40 → line ③ → heat exchanger 20 → line ③ → compressor 30 → line ③ → reactor 10.

2) When the F ₂ compressor 30 operates normally, the AHF circulation pump 50 is operated to circulate the AHF. At this time, AHF is circulated from top to bottom in the order of reactor 10 → AHF circulation pump 50 → line ④ → column 40 → reactor 10.

At this time, the arsenic compound (AsF ₃ ) present in the Crude-AHF and the F ₂ gas are reacted, and the reaction time is 36 hours or less, preferably 24 hours or less, and very preferably 4 hours to 24 hours. When the reaction time is less than 4 hours, the conversion rate decreases, which is not preferable, and when the reaction time exceeds 36 hours, there is a point in which the increase in the conversion rate is insufficient.

3) In addition, the core of this process _{is that the F 2} gas and AHF are in countercurrent contact within the column 40 at a very high speed _{using the F 2} compressor 30 and the AHF circulation pump 50 to perform the reaction. At the same time, the reaction is carried out in the reactor again through the deep nozzle 11 installed in the reactor 10 to maximize the conversion rate of _{AsF 3} + F ₂ → AsF _5.

_{In addition, the unreacted F 2} gas that has not participated in the oxidation reaction is continuously circulated without being discharged to the outside of the reactor, thereby _{reducing the amount of F 2} gas used, thus enabling economic product production.

3. AsF ₅ Absorption process

This step is selected _{from liquid XAsF x} (OH) _y (X = Na, K, Li, Ca, Ba; x = 5 to 7; y = 0 or 1 _{by reacting the oxidized AsF 5} gas with an absorbent liquid. ) It is a process of forming a compound and discharging it as it is, and at the same time discharging AsF _{5 gas that did not participate in the reaction to the atmosphere.}

At least one Lewis base selected from the group consisting of NaOH, NaF, LiF, KOH, KF, CaF ₂ , and BaF _{2 is preferable as an absorbent for absorbing AsF 5} gas in this process. Any material that is inexpensive and inexpensive can be used.

The concentration of each of the absorbing solution used in the present invention is 0.1, so a preferable to increase the reaction rate of not-absorbed solution and AsF ₅ gas was 5% by weight, different solubility to each substance by water should be selected an appropriate concentration XAsF _x ( OH) _y (X = selected from Na, K, Li, Ca, Ba; x = 5 ~ 7; y = 0 or 1) It will be able to increase the absorption rate in compound formation.

_{Of course, the arsenic compounds including unreacted AsF 5} gas released to the atmosphere are less than 0.5 ppm, which is an allowable emission concentration. (See Fig. 2)

The detailed process is as follows.

1) When the oxidation reaction in the reactor 10 is completed, the operation of the AHF circulation pump 50 is first stopped, and then the operation of the F ₂ compressor 30 is stopped.

2) Steam is injected into the jacket 60 installed outside the reactor 10 to total reflux the AHF inside the reactor.

3) The liquid circulation pump 70a is operated to increase the absorption rate.

_{4) After confirming that the liquid circulation pump 70a is circulating normally, AsF 5} gas is slowly flowed through the upper portion of the heat exchanger 20 to the lower portion of the first absorption tower 80a. That is, in order to increase the absorption rate, AsF ₅ gas is injected into the lower part of the absorption tower through line ⑤, and the absorption liquid is injected into the first absorption tower 80a through the liquid circulation pump 70a from the top to the bottom (line ⑧). Make countercurrent contact.

5) The gas removed in this way is introduced into the lower portion of the second absorption tower 80b through the movement path ⑥, and unreacted AsF ₅ is additionally removed in the same manner as in 3) and 4) above.

_{AsF 5} gas oxidized in this step is reacted with an absorbent liquid to react with liquid XAsF _x (OH) _y (X = selected from Na, K, Li, Ca, Ba; x = 5 to 7; y = 0 or 1) In forming the compound, the first method to increase the absorption rate (reactivity) can be achieved by controlling the rate _{of the injected AsF 5 gas.} That is, _{it can be said that the rate of introduction of the AsF 5} gas is 100 to 5,000 ml/hr, which is a desirable rate capable of increasing the absorption rate.

In addition, as a second method of increasing the absorption rate, AsF ₅ gas is used from the bottom to the top; The absorbent liquid is transferred from the top to the bottom through the liquid circulation pump 70a so as to react in countercurrent contact with each other in the absorption towers 80a and 80b.

In addition, a third way to increase the absorption rate is to arrange the absorption towers in series. The illustrated absorption towers 80a and 80b are two, but are not limited thereto, and the number of absorption towers may be increased according to the input rate or throughput.

That is, the AsF ₅ gas is absorbed into the absorption liquid as much as possible through the above process, thereby minimizing the concentration of arsenic compounds including the _{unreacted AsF 5 gas that is subsequently discharged to the atmosphere.}

4. Arsenic compound discharge process

This process is a process of discharging the _{AsF 5} gas, which has not reacted with the absorbent liquid in the third step, to the atmosphere. The gas that has passed through the absorption towers 80a and 80b is discharged to the atmosphere through flow ⑦. _{At this time, since the concentration of the arsenic compound including AsF 5} gas that has not reacted with the absorbent liquid is maintained below 0.5 ppm, which is the allowable emission concentration, it can be discharged to the atmosphere.

The overall concept of removing As by using the _{F 2} gas according to the present invention is schematically shown in FIG. 2 below.

Hereinafter, a preferred embodiment of the present invention will be described in detail. The following examples are for illustrative purposes only, and the scope of the present invention should not be construed as being limited by these examples. In addition, in the following examples, specific compounds are used, but it is obvious to those skilled in the art that even when their equivalents are used, an effect of an equal or similar degree can be exhibited.

Example: Preparation of ultra-high purity hydrogen fluoride

1) Crude-AHF and F ₂ Gas input process

_{Crude-AHF containing an arsenic compound (AsF 3} ) at the concentration shown in Table 1 below was supplied to the reactor 10 through line ①. When the supply of Crude-AHF to the reactor 10 was finished, F ₂ gas, an oxidizing agent, was supplied to the reactor 10 through line ②. At this time, the molar ratio of the arsenic compound (AsF ₃ ) and F ₂ gas to be introduced is shown in Table 1 below.

2) AsF ₃ + F ₂ → AsF ₅ Furnace oxidation process

This step is a process of converting _{HF and AsF 3} , an azeotropic substance, into an easy-to-separate AsF _{5 form by oxidizing it using F 2 gas.}

When the injection of the Crude-AHF and F ₂ gas was completed, the F ₂ compressor 30 was operated to circulate _{the F 2 gas.} At this time, the F ₂ gas was introduced by bubbling through the dip nozzle 11 installed in the reactor 10. The F ₂ gas was circulated from bottom to top in the order of reactor (10) → column (40) → line ③ → heat exchanger (20) → line ③ → F ₂ compressor (30) → line ③ → reactor (10). .

When the F ₂ compressor 30 operates normally, the AHF circulation pump 50 is operated to circulate AHF. At this time, AHF was introduced into the column 40 from the bottom of the reactor to be circulated back to the reactor. At this time, the reaction time is 1~36hr.

In order to check whether the oxidation reaction proceeded well, the gaseous AsF ₅ was removed from the inside of the reactor after the reaction was completed, and then the AHF inside the reactor was collected in a liquid state, and ICP analysis was performed according to JIS K8819 to Arsenic (AsF _5). ) The concentration was measured.

Table 1 below shows _{the conversion rate of AsF 3} to AsF ₅ according to the _{Crude AHF: F 2} molar ratio during the oxidation reaction to _{AsF 3} + F ₂ → AsF ₅ Oxidation, and in Table 2 below, Crude AHF: F _{The 2} molar ratio was fixed at 1:5, and the conversion rate according to the reaction time was measured while changing the reaction time as shown in Table 2 below. Conversion rate was calculated by the following equation.

Crude AHF: F ₂ input molar ratio Arsenic(AsF ₃ ) concentration in AHF after reaction (ppm) Conversion rate (%) 1: 100 0.04 99.20 1: 50 0.042 99.16 1: 5 0.050 99.00 1: 1 1.000 80.00 Reaction time: 36hr, Arsenic concentration in Crude AHF: 5ppm

Referring to the results of Table 1, it was confirmed that the higher the molar ratio of the _{F 2 gas input, the higher the conversion rate.} It was confirmed that the Crude AHF:F ₂ molar ratio showed a conversion rate of 99% or more in the molar ratio range of 1:5 or more and 1:5 to 100.

Reaction time (hr) Arsenic concentration in AHF after reaction (ppm) Conversion rate (%) 36 0.050 99.00 24 0.052 98.96 4 0.490 90.2 One 3.800 24.00 Crude AHF: F ₂ input molar ratio = 1: 5, Arsenic concentration in Crude AHF: 5ppm

Referring to the results of Table 2, it was confirmed that the conversion rate increased as the reaction time increased, and the conversion rate was 90% or more at the reaction time of 4 hours or more.

3) AsF ₅ Absorption process

This process is selected _{from liquid XAsF x} (OH) _y (X = Na, K, Li, Ca, Ba; x = 5 to 7; y = 0 or 1 _{by reacting the oxidized AsF 5} gas with an absorbent liquid. ) The compound is formed and discharged as it is, and at the same time, the arsenic compound containing _{AsF 5 gas that does not participate in the reaction is} It is a process that discharges to the atmosphere at a concentration of 0.5ppm or less, which is the allowable emission concentration.

When the oxidation reaction in the above 2) was completed, the operation of the AHF circulation pump 50 was stopped as shown in FIG. 1, and then the operation of the F ₂ compressor 30 was stopped. In addition, steam was injected into the jacket 60 mounted outside the reactor 10 to total reflux the AHF inside the reactor.

In order to increase the reaction rate, the liquid circulation pump 70a is operated, and then AsF ₅ gas is injected into the lower portion of the first absorption tower 80a through the upper portion of the heat exchanger 20. The input rate was passed through each as described in the table below. The gas that passed through the first absorption tower 80a was introduced into the lower portion of the second absorption tower 80b through the movement path ⑥, and additionally removed _{unreacted AsF 5 that could not be removed from the first absorption tower 80a.}

In addition, the _{absorbent liquid for absorbing the AsF 5} gas was injected into the first absorption tower 80a while changing as shown in Table 3 below.

Experimental Example 1: AsF ₅ Absorption rate measurement

Was first absorber (80a) measuring the concentration deployment.Whoa AsF ₅ 4.948ppm first absorber (80a) and the second absorption tower ₅ AsF density after (80b) passing through each in respect to the above embodiments, the result It is shown in Tables 3 and 4 below. Tables 3 and 4 below show arsenic compounds according to the type of absorbent (Table 3) and absorption rate (Table 4) when _{AsF 5} gas converted in the oxidation process is absorbed in the absorption tower in order to reduce the concentration of arsenic compounds released to the atmosphere. It shows the outlet concentration.

Absorbent _{Arsenic (AsF 5} ) concentration after passing through the first absorption tower (ppm) _{Arsenic (AsF 5} ) concentration after passing through the second absorption tower (ppm) 4% by weight-NaOH 0.989 0.197 4% by weight-NaF 1.187 0.285 0.25% by weight-LiF 1.568 0.497 _{AsF 5} concentration before the first absorption tower input: 4.948ppm, input rate: 1,000ml/hr

Referring to the results of Table 3, when _{the concentration of AsF 5} before the absorption tower is added is 5 ppm or less and the input rate is set to 1,000 ml/hr, Having a concentration of 0.1 to 5% by weight It was confirmed that NaOH, NaF, and LiF all satisfied the allowable discharge concentration of arsenic compounds after passing through the absorption tower.

Dosing speed (ml/hr) Arsenic concentration after passing through the first absorption tower (ppm) Arsenic concentration after passing through the second absorption tower (ppm) 5,000 1.548 0.484 1,000 0.989 0.197 100 0.430 0.037 _{AsF 5} concentration before the first absorption tower input: 4.948ppm, absorption liquid: 4%-NaOH

In addition, referring to the results of Table 4, when using 4% NaOH as the absorption liquid, the faster the injection rate, the lower the absorption rate, and it was confirmed that the injection rate of about 1,000 ml/hr is economically most suitable. However, the input rate is only an example in the present invention and may vary depending on the amount of circulation of the absorbent liquid and the internal design of the absorption tower.

From these results, in the present invention, it was confirmed that the method of recycling by countercurrent contacting the _{F 2} gas and the Crude AHF liquid in order to maximize the use of _{100% F 2 gas and the contact efficiency when producing ultra-high purity hydrogen fluoride.} It was confirmed that the removal of the arsenic compound in the form of _{AsF 5} converted by the same method can be continuously removed in NaOH, NaF, and LiF aqueous solutions. In particular, since this process does not use an oxidation catalyst for treating arsenic compounds, it has been confirmed that there is no regeneration process, so that arsenic compounds can be removed in an economical way.

Claims (12)

The first step of introducing natural-anhydrous hydrofluoric acid (Crude-AHF) containing AsF _{3 and F 2 gas as an oxidizing agent into the reactor,}
I) The F ₂ gas and _{natural-anhydrous hydrofluoric acid (Crude-AHF) containing AsF 3} are first brought into countercurrent contact in a column connected to the reactor, and at the same time,
Ii) a second step of producing _{AsF 5} gas by oxidation reaction of _{the AsF 3} and F ₂ gas, which is configured to be secondary inside the reactor through a dip nozzle installed in the reactor,
_{XAsF x} (OH) _y (X = selected from Na, K, Li, Ca, Ba; x = 5 to 7; y = 0 or 1) to form a compound by reacting the prepared AsF ₅ gas with an absorbent liquid Step 3, and
A method for removing and treating arsenic compounds in hydrogen fluoride when producing ultra-high purity hydrogen fluoride gas comprising a fourth step of discharging the _{AsF 5} gas that has not reacted with the absorbent liquid in the third step to the atmosphere.
The method of claim 1,
The removal and treatment method that the concentration of _{the arsenic compound (AsF 3} ) present in the natural-anhydrous hydrofluoric acid (Crude-AHF) of the first step is 0.5 to 1,000 ppm.
The method of claim 1,
_{The removal and treatment method that the AsF 3} and F ₂ gas of the first step are introduced in a molar ratio of 1:5 to 100.
The method of claim 1,
The removal and treatment method that the oxidation reaction time of the second step is 4 to 36 hours.
delete The method of claim 1,
_{The removal and treatment method that the unreacted F 2} gas that did not participate in the oxidation reaction of the second step is continuously circulated and reused without being discharged to the outside of the reactor.
The method of claim 1,
_{The reaction of the AsF 5} gas and the absorbent liquid in the third step is performed in the absorption tower;
The AsF ₅ gas is transferred from the bottom of the absorption tower to the top, and the absorption liquid is transferred from the top of the absorption tower to the bottom of the absorption tower to make countercurrent contact with each other.
The method of claim 7,
The removal and treatment method that the AsF ₅ gas is introduced into the absorption tower at a rate of 100 to 5,000 ml/hr.
The method of claim 1,
The absorbing solution is NaOH, NaF, LiF, KOH, KF, CaF 2, and with at least one member selected from the group consisting of BaF _2, the concentration is 0.1 to the removal and treatment method of a 5% by weight.
The method of claim 7,
The absorption tower may be plural, and they are arranged in series.
The method of claim 1,
The third step of XAsF _x (OH) _y (X = selected from Na, K, Li, Ca, Ba; x = 5 to 7; y = 0 or 1) compound is in a liquid state, and discharged and removed as it is. Removal and treatment method that is to be.
The method of claim 1,
_{Arsenic compounds including AsF 5} gas that did not react with the absorbent liquid of the fourth step is a removal and treatment method having an allowable emission concentration of 0.5 ppm or less.

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