KR20040002663A - Material and method for purification of gas containing nitrogen fluorides - Google Patents

Abstract

PURPOSE: To provide a purifying agent and purifying method, which can relatively stably and easily be stored and handled in air for purifying a gas containing nitrogen fluorides such as nitrogen trifluoride, which does not cause overheating for certain kinds of diluting gas during purifying or sudden heat generation or production of harmful gas in the subsequent treatment of purification, which does not induce increase in the pressure loss or clogging in a purification cylinder during purifying, which does not emit NOx but can efficiently purify a gas containing nitrogen fluorides. CONSTITUTION: The purifying agent contains tin(II) oxide and at least one kind of compound selected from oxides, hydroxides and carbonates of alkaline earth metals and oxides, hydroxides and carbonates of lanthanoids as an effective component. The gas containing nitrogen fluorides is purified by bringing the gas into contact with the above purifying agent while heating.

Description

Purifying agent and purification method of gas containing nitrogen fluoride {MATERIAL AND METHOD FOR PURIFICATION OF GAS CONTAINING NITROGEN FLUORIDES}

The present invention relates to a purifier and a method for purifying a gas containing nitrogen fluoride. More specifically, it is easy to store and handle relatively stable in air and contains nitrogen fluoride discharged from semiconductor manufacturing process or the like without any risks during post-treatment during or after purification and without emitting NOx. A purifying agent and a purifying method capable of efficiently purifying a gas.

In the semiconductor manufacturing industry, nitrogen trifluoride is used as a dry etching gas such as silicon or silicon oxide, or as a chamber cleaning gas for a CVD apparatus. Nitrogen trifluoride has a low solubility in water and reacts mostly with both acids and alkalis. It is very stable at room temperature, etc. It is also reported that the allowable concentration outside the range that the effect on global warming is considered to be 10 ppm is high, and because it is highly toxic and adversely affects the human body and the environment if released to the atmosphere. It is necessary to purify after use in the semiconductor manufacturing process.

Nitrogen trifluoride is stable at room temperature and normal pressure, but it generates nitrogen fluorides such as dinitrogen tetrafluoride, dinitrogen difluoride and dinitrogen hexafluoride by heat and discharge during dry etching and cleaning processes. These gases are more toxic than nitrogen trifluoride. As it is strong, we have to purify like nitrogen trifluoride.

Conventionally, as a purifier of nitrogen fluoride, a purifier comprising calcium and / or magnesium as an active ingredient (Japanese Patent Application Laid-Open No. 6-99033), a metal zinc, a metal aluminum, or a mixture of both of them (JP-A 6-134256). Publications), purifiers consisting of zirconium or zirconium-based alloys (Japanese Patent Application Laid-Open No. 6-238128), and purifiers (Japanese Patent Application Laid-Open No. Hei 11-5018) containing tin oxide as an active ingredient have been developed. Because it is stable at, it is purified under heating by using any purifier.

As other purification methods, a method of introducing a nitrogen fluoride-containing gas into a flame of an incinerator using hydrogen, methane, propane, or the like, and burning it in contact with a metal oxide under heating to purify it is proposed.

However, a purifier based on calcium and / or magnesium or a purifier based on metal zinc, metal aluminum or a mixture of both is difficult to store and handle because the active ingredient, the main component, is easy to react with oxygen or water. The post-treatment of the unreacted purifier after purification involves the risk of rapid heat generation and generation of harmful gases. In addition, purifiers composed of zirconium or zirconium-based alloys are stable in air at room temperature but react strongly with oxygen at high temperatures close to the purge temperature. Furthermore, due to the high concentration of nitrogen trifluoride, they are usually used as diluent gases of nitrogen trifluoride. It also reacts severely with nitrogen and may cause thermal runaway.

In addition, since the purifying agent having tin tin oxide as an active ingredient is relatively stable in high temperature air at room temperature, the density of SnF ₂ produced by purifying gas containing nitrogen trifluoride is small compared with SnO as an active ingredient, Decontamination of the purifier Even though the end of the reaction expands and causes pressure loss or blockage in the sump and the purge capacity remains, the purge needs to be continued in exchange for a new purifier. It is inconvenient to discharge NOx because it is introduced into the flame of combustion and burned, and the method of purifying by contact with metal oxide under heating.

Therefore, the problem to be solved by the present invention is in the purification of gas containing nitrogen fluoride, such as nitrogen trifluoride, relatively stable in air, easy to handle and handle, and intense reaction with diluent gas during purification to cause thermal runaway or purification During post-treatment, it does not cause sudden heat generation or harmful gas generation, and does not cause an increase or blockage of pressure loss in the septic tank during purification, and does not emit NOx and efficiently purifies gas containing nitrogen fluoride. It is to provide a purifying agent which can be used and a purification method using the same.

The present inventors have focused on solving these problems, and as a result, a purifier comprising at least one compound selected from oxides, hydroxides, carbonates, lanthanoids, hydroxides, and carbonates of tin oxide and alkaline earth metals as an active ingredient It is found to be relatively stable in air, and to be easy to store and handle.

In addition, the present inventors contact a gas containing nitrogen fluoride as a harmful component with the purifier under heating, react with the diluent gas intensely during purification, causing thermal runaway, or sudden heat generation or harmful gas during post-treatment after purification. It has been found that the gas containing nitrogen fluoride can be efficiently purified without causing any increase of pressure loss or blockage in the septic tank during the purification and without releasing NOx. A purifying agent and a method of purifying the gas containing fluoride have been achieved.

In other words, the present invention is a purifier of a nitrogen fluoride-containing gas comprising at least one compound selected from oxides, hydroxides, carbonates, lanthanoids, hydroxides, and carbonates of stannous oxide and alkaline earth metals as an active ingredient. ．

In addition, the present invention is an active ingredient using one or more compounds selected from oxides, hydroxides, carbonates, lanthanoid oxides, hydroxides, carbonates of stannous oxide and alkaline earth metals under heating of a gas containing nitrogen fluoride as a harmful component as an active ingredient The present invention also relates to a method for purifying a nitrogen fluoride-containing gas, which is purified by contact with a purifying agent included.

The purifying agent and the purifying method of the nitrogen fluoride-containing gas of the present invention are purifying agents and purifying agents for purifying nitrogen fluorides such as nitrogen trifluoride, dinitrogen tetrafluoride, dinitrogen difluoride, dinitrogen hexafluoride and the like contained in gases such as nitrogen, argon and helium. The purifying agent of the nitrogen-fluoride-containing gas of the present invention comprises at least one compound selected from oxides, hydroxides, carbonates, lanthanoid oxides, hydroxides and carbonates of stannous oxide and alkaline earth metals as active ingredients. It is a purifying agent that contains.

Further, the purifying method of the gas containing nitrogen fluoride of the present invention is a purifying method of purifying a gas containing nitrogen fluoride by contacting the purifying agent under heating.

Hereinafter, the purifier of the gas containing nitrogen fluoride of this invention is demonstrated in detail.

In the purifying agent of the present invention, since tin tin oxide (SnO) used as one of the active ingredients is commercially available at a purity of 98% or more in the state of powder or the like, such a commercial item can usually be used.

In addition, oxides, hydroxides, carbonates, lanthanoid oxides, hydroxides and carbonates of alkali alkaline earth metals other than the above are beryllium, magnesium, calcium, strontium, barium, lanthanum, cerium, prasedium, neodium, samarium, Although oxides, hydroxides, and carbonates such as europium can be exemplified, in view of low cost and easy availability, it is preferable to use oxides, hydroxides, carbonates of magnesium, calcium, strontium or lanthanum. Moreover, these alkaline earth metal compounds and lanthanoid compounds may be used independently and may use two or more types together.

The purifying agent of the present invention is such that the ratio of the atomic number of the sum of the atomic number of tin and the alkaline earth metal and the lanthanoid atom in the purifier is 1: 0.1 to 2.0, preferably 1: 0.3 to 1.0. It was prepared as much as possible. In addition, the active ingredient of the alkaline earth metal and the lanthanoid based egg-scavenging agent in the " atomic number of the alkaline earth metal and the lanthanoid-based atom number " (oxides, hydroxides, carbonates and lanthanoids of alkaline earth metals). Atoms derived from oxides, hydroxides, and carbonates), and do not include atoms derived from the molding aids described below. Atoms in which tin atoms of the alkali earth metal and lanthanoid atoms are added together If less than 10% of the water, the reaction mainly converts SnO into SnF ₂ during the purification of the gas containing nitrogen trifluoride. SnF ₂ has a density of 4.57 g / cm ³ , the main component SnO (density 6.95 g / cm ³⁾ as compared to the harm-elimination reaction was completed part of the cleaning agent by expansion is small, the inconvenience arises that causes the increase in pressure loss, or clogging in a cleaning column. in addition, an alkaline earth If the number of atoms plus the number of atoms in number of atoms of metal and lanthanide more than 2.0 times the number of tin atoms is caused a problem that the NOx emissions.

In addition, the purifying agent of the present invention may be added to the active ingredient in order to increase the moldability and molding strength during assembly. Examples of such molding aids include lithium fluoride, sodium fluoride, potassium fluoride, magnesium fluoride, calcium fluoride, lanthanum fluoride and the like. Although metal fluorides may be used, potassium fluoride is particularly preferable because of its excellent effect of increasing the molding strength. These may be used alone or in combination of two or more. These molding aids are effective when preparing a purifying agent. It is added to the components and kneaded. The addition amount of the molding aid varies depending on the molding conditions and the like and is not particularly limited. If too small, the effect as a molding aid cannot be obtained, and in too many cases, the purifying capacity is lowered, and it is usually 0.1 to 10 wt% with respect to the total weight of the purifier, preferably 0.5 to 5 wt%.

In addition, the purifying agent of the present invention may contain impurities, inert substances, and the like, which do not adversely affect the purifying of nitrogen fluoride. Further, the purifying agent before use may contain water, but preferably no water, and is usually water in the purifying agent. It is prepared to be 2 wt% or less. In the case of containing such molding aids, impurities, inert substances, moisture, and the like, the content of the active ingredient in the purifying agent is usually 70 wt% or more, preferably 90 wt% or more.

There is no particular limitation with regard to the method of shaping the purifying agent of the present invention, for example, water is added to the purifying component to form a slurry or cake, followed by extrusion molding, cutting and drying to a suitable length, or The method of granulation by compression molding can be used.

In addition, the purifying agent of the present invention may be prepared by mixing molding tin oxide and the like with one or more compounds selected from the above-described alkali earth metal compounds and lanthanoid compounds, and the like.Tin oxide and alkaline earth metal compounds and lanthanoid compounds After molding each of one or more compounds selected from the back and the like, these may be mixed and prepared.

In any of the preparation methods, the purifying agent of the present invention usually has a spherical shape of about 1 to 100 mm, a diameter of about 0.5 to 5 mm and a columnar shape having a length of about 2 to 20 mm, or a similar shape, or a size and shape corresponding thereto. It is molded to be prepared.

Next, the method for purifying the gas containing nitrogen fluoride of the present invention will be described in detail. The purifying method of the present invention is a method for purifying a gas containing nitrogen fluoride by contacting with a purifying agent as described above under heating. When it is used as a part of the active ingredient of the purifying agent, and hydroxides, carbonates, lanthanoid hydroxides and carbonates of alkaline earth metals are used, some of the compounds described above become oxides under heating, and oxides of alkaline earth metals and lanthanoid oxides. It is effective as.

In the case of purifying a gas containing nitrogen trifluoride by contacting with a purifying agent containing stannous oxide and calcium oxide as an active ingredient according to the purifying method of the present invention, the following formulas (1) (2) or (3) In the purification method of the present invention, CaSnF ₆ , SnO ₂ , and CaF ₂ are produced as apparent from the above reaction formula, but the volume of the active ingredient of the purifying agent before reacting with the combined volume of these reaction products. Since the difference is small, there is no fear that the filling member (purifier and reaction product) of the swelling container expands and causes an increase in pressure loss or blockage in the septic tank.

For example, if the reaction of equation (3), active ingredients, SnO, density, and each density of 6.95g / cm ^3, 3.37g / reaction product as cm ³ SnO _2, CaF ₂ CaO of the cleaning agent is respectively 7 .Og / cm ³ , 3.08g / cm ³ and these are equimolar ratios, so the smaller the difference in the average density of the quantum, the smaller the difference in volume.

3SnO + CaO + 2NF ₃ → 2SnO ₂ + CaSnF ₆ + N ₂ (Equation 1)

6SnO + 4CaO + 4NF ₃ → 5SnO ₂ + 3CaF ₂ + CaSnF ₆ + 2N ₂ (Equation 2)

3SnO + 3CaO + 2NF ₃ → 3SnO ₂ + 3CaF ₂ + N ₂ (Equation 3)

In the above reaction, when a lanthanoid compound such as La ₂ O _{3 is} used in place of an alkaline earth metal compound such as CaO, the gas containing nitrogen fluoride is purified according to the above reaction formula.

In the purifying method of the present invention, the temperature at which the gas containing nitrogen fluoride is brought into contact with the purifying agent is usually 200 to 800 ° C, preferably 250 to 600 ° C. When the temperature is lower than 200 ° C, the purifying capacity of nitrogen fluoride is not high. In addition, when the temperature is higher than 80 ° C., it is impossible to use stainless steel in the septic tank, which causes the inconvenience of requiring a material having higher heat resistance.

In addition, although the pressure in a purification container at the time of purifying is normal pressure, it is 1K, for example.

It can also be performed under pressure of about 0.2 MPa (absolute pressure) from the reduced pressure of about Pa.

In the purifying method of the present invention, a purifying tank for filling a purifying agent is generally cylindrical, and its size is usually 10 to 500 mm in inner diameter and about 20 to 2000 mm in length. The filling length of the purifying agent filled in the purifying container is usually about 10 to 100 mm, Preferably it is about 50-500 mm. If the filling length of the purifier is less than 10 mm, the purge of the gas containing nitrogen fluoride becomes insufficient, and the pressure loss increases if it is 100 mm or more. In addition, as a means for heating the purifier, a heater is usually installed outside the purifier. The temperature is controlled by a control device. In addition, in the purification method of the present invention, in addition to using the purification agent as a stationary phase, it can also be used as a fluidized bed.

Although the flow rate of the gas containing nitrogen fluoride in the case of applying the purification method of the present invention is not particularly limited, it is generally preferable to reduce the flow rate so that the concentration of the nitrogen fluoride contained in the gas becomes high. Is usually 1% or less, but when the flow rate is small, it is possible to purify a gas containing a high concentration of nitrogen fluoride.

The septic tank is designed according to the nitrogen fluoride concentration and flow rate, but if the nitrogen fluoride concentration is relatively low, such as 0.1% or less, the hollow cylinder linear velocity (LV) is 0.5 to 50 cm / sec and the nitrogen fluoride concentration is about 0.1 to 1%. LV is preferably designed in the range of 0.05 to 20 cm / sec and the concentration of nitrogen fluoride is not more than 10 cm / sec if the concentration is 1% or more.

Example

Next, the purifying agent and the purifying method of the gas containing the nitrogen fluoride of the present invention will be described in detail according to the examples, but the present invention is not limited thereto.

Example 1

(Preparation of Purifier)

Commercially available stannous oxide (99% purity) and calcium oxide (99% purity) were pulverized until 100 mu m or less, and the mixture was mixed so that the atomic number ratio (Sn: Ca) was 1: 0.5. After filling the mold with the inner diameter of 20mm and the height of 5mm, the tablet obtained by molding by pressurizing for 10 seconds at the pressure of 15 ~ 16Okg / cm ² using the hydraulic jack is crushed and sieved and passed through the body of 3.36mm and the body of 2.00mm What did not pass was used as a purifier.

(Purification test)

The purifier was filled in a SUS316L purifier with an inner diameter of 23.9 mm and a length of 200 mm so that the filling length was 100 mm. After heating the purifier in the purifier to 400 ° C., NF ₃ (flow rate 13.46 ml / min) was added. Nitrogen containing (total flow rate 1346 ml / min) was introduced into the clarifier and the gas containing NF ₃ was purged.

At this time, every 10 minutes, a part of the purge gas discharged from the discharge port of the

Analyze by gas chromatography (lower limit of detection of 10 ppm), determine the time until NF ₃ is detected, and determine the purification throughput (L) (purification capacity) of NF ₃ per 1 L (liter) of purifying agent. At the same time, the presence or absence of NOx emission was investigated through a detection tube (manufactured by Gas Tech Co., Ltd.). The results are shown in Table 1.

Example 2, 3

In the preparation of the purifying agent of Example 1, the mixing ratio of stannous oxide and calcium oxide was mixed in the same manner as in Example 1 except that the ratio of atomic number (Sn: Ca) was 1: 0.3 and 1: 0.75, respectively. Purifying agent was prepared. Using this purifying agent, a purification test of NF ₃ was conducted in the same manner as in Example 1. The results are shown in Table 1.

Examples 4 and 5

In the purification test of Example 1, 0.2% of the concentration of NF _3, respectively, and the same procedure as in Example 1 except that a 2.0% change in the test was performed for purification of NF ₃ Table 1 shows the results.

Examples 6 and 7

In the preparation of the purifying agent of Example 1, the purifying agent was prepared in the same manner as in Example 1 except that calcium oxide was changed to calcium hydroxide and calcium carbonate, respectively. NF _{3 was prepared in the} same manner as in Example 1 using the purifying agent. The purification test was carried out. The results are shown in Table 1.

Examples 8 and 9

In the preparation of the purifying agent of Example 1, the purifying agent was prepared in the same manner as in Example 1 except that calcium oxide was changed to magnesium oxide and strontium oxide, respectively. Using this cleaning agent in Example 1 was identically performed tests purification of NF _3. Table 1 shows the results.

Example 10

(Preparation of Purifier)

Commercially available stannous oxide (99% purity) and lanthanum oxide (99% purity) were pulverized until 100 mu m or less, and the mixture was mixed so that the atomic number ratio (Sn: La) was 1: 0.5. After filling the mold with the inner diameter of 20mm and the height of 5mm, the tablet obtained by molding by pressurizing the pressure at 150 to 160kg / cm ² for 10 seconds by using the hydraulic jack is crushed, and it is sieved and passed through the body of 3.36mm and 2.00mm The body did not pass through as a purifying agent.

(Purification test)

The purifier was filled in a purifying container made of SUS316L material having an inner diameter of 23.9 mm and a length of 200 mm so as to have a filling length of 100 mm. After the temperature of the purifying agent in the purifier was heated to 400 ° C, nitrogen containing NF ₃ (flow rate 13.46 ml / min) (total flow rate 1346 ml / min) was introduced into the purifier to purify the NF ₃ -containing gas.

At this time, every 10 minutes, a part of the purge gas discharged from the discharge port of the purification tank is collected and analyzed by gas chromatography (low limit value 10 ppm), and the time until NF ₃ is detected is measured per 1 L (liter) of purifier. The purification amount L (purification capacity) of NF ₃ was determined, and the presence or absence of NOx emission was examined through a detection tube (manufactured by Gas Tech Co., Ltd.). The results are shown in Table 1.

Examples 11 and 12

In the preparation of the purifying agent of Example 10, the mixing ratio of stannous oxide and lanthanum oxide was mixed in the same manner as in Example 10 except that the ratio of atomic number (Sn: La) was 1: 0.3 and 1: 0.75, respectively. The purification agent was prepared. The purification test of NF ₃ was performed like Example 10 using this purification agent. The result is shown in Table 1.

Example 13, 14

Carried out the purification test of Example 10, the NF ₃ concentration was 0.2% and the respective row in the same manner as in Example 10 except that a 2.0% change in the test purification of NF ₃ in. Table 1 shows the results.

Example 15, 16

In the preparation of the purifying agent of Example 10, the purifying agent was prepared in the same manner as in Example 10 except that the lanthanum oxide was changed to lanthanum hydroxide and lanthanum carbonate, respectively. NF _{3 was prepared in the} same manner as in Example 10 using the purifying agent. Purification test was performed.

The results are shown in Table 1.

Example 17

(Preparation of Purifier)

Commercially available stannous oxide (99% purity), calcium oxide (99% purity), and lanthanum oxide (99% purity) are pulverized until 100 mu m or less, and the atomic number ratio (Sn: Ca: La) is 1: 0.3: 0.2 was mixed so that the mixed mixture was filled into a mold having an inner diameter of 20 mm and a height of 5 mm, and then pressurized for 10 seconds at a pressure of 150 to 160 kg / cm ² using a hydraulic jack to crush the tablet obtained. This was sieved and passed through a body of 3.36 mm and did not pass through a body of 2.00 mm as a purifying agent.

(Purification test)

The purifier was filled in a purifying container made of SUS316L material having an inner diameter of 23.9 mm and a length of 200 mm so as to have a filling length of 100 mm. After the temperature of the purifying agent in the purifier was heated to 400 ° C, nitrogen containing NF ₃ (flow rate 13.46 ml / min) (total flow rate 1346 ml / min) was introduced into the purifier to purify the NF ₃ -containing gas.

At this time, every 10 minutes, a part of the purge gas discharged from the outlet of the septic tank is collected and analyzed by gas chromatography (lower limit of detection limit of 10 ppm), and the time until NF ₃ is detected is measured and NF per 1 L (liter) of purifier is measured. a _third purification throughput (L) (purifying capacity) of at the same time as wanted, were investigated for the presence of the NOx discharged through the detector tube (Co. gas Tech agent). The results are shown in Table 1.

Example 18

Example 17 The preparation of the purifying agent of Example 17, except that the mixing ratio of stannous oxide, calcium oxide, and lanthanum oxide was mixed so that the ratio of atomic number (Sn: Ca: La) was 1: 0.2: 0.3 A purifying agent was prepared in the same manner as described above. Using this purifying agent, a purification test of NF ₃ was conducted in the same manner as in Example 17. The results are shown in Table 1.

Comparative Example 1

(Preparation of Purifier)

To 1000 g of commercially available tin tin (99% purity), 50 g of potassium fluoride (KF, Kanto Chemical Co., Ltd., Regent Express) was dissolved in 65 g of water, and an aqueous solution was mixed and added. The molded product obtained by extruding from a nozzle plate having a diameter of 1.6 mm at was cut into pieces, and pellets having a length of 3 to 5 mm were made and dried for about 12 hours while heating at 120 ° C. under a nitrogen atmosphere to prepare a purifying agent.

(Purification test)

The purification test of NF ₃ was carried out in the same manner as in Example 1 except that the above purification agent was used. However, the purification test was stopped because the pressure drop of the purification container was large before NF ₃ was detected. Table 1 shows the results of obtaining the purification throughput L (purification capacity) of NF ₃ per liter of purification agent from the time until the purification test was stopped.

Comparative Example 2

Commercially available calcium oxide (99% purity) was pulverized until it became 100 µm or less and filled into a mold having an inner diameter of 20 mm and a height of 5 mm, and then pressurized for 10 seconds at a pressure of 150 to 160 kg / cm ² using a hydraulic jack. The tablet obtained was crushed and sieved to pass through a body of 3.36 mm and not to pass a body of 2.00 mm as a purifying agent.

A purification test of NF ₃ was carried out in the same manner as in Example 1 except that the above purification agent was used.

I did it. However, immediately after the start of the purge test, the purge test was discontinued as the emission of thousands of ppm of NO was confirmed.

Comparative Example 3

Commercially available lanthanum oxide (99% purity) was pulverized until it became 100 µm or less and filled into a mold having an inner diameter of 20 mm and a height of 5 mm, and pressurized for 10 seconds at a pressure of 150 to 160 kg / cm ² using a hydraulic jack. The tablet obtained was crushed and sieved to pass through a body of 3.36 mm and not to pass a body of 2.00 mm as a purifying agent.

A purification test of NF ₃ was conducted in the same manner as in Example 1 except that the above purification agent was used. However, the purification test was stopped as soon as the discharge of thousands of ppm was confirmed.

Table 1

Purifying agent ingredient (ratio of atomic number) Hazardous Ingredients Concentration (%) Purification temperature (℃) Purification Capacity NOx emissions Example 1 SnO, CaO (1: 0.5) NF ₃ 1.0 400 124 none Example 2 SnO, CaO (1: 0.3) NF ₃ 1.0 400 132 none Example 3 SnO, CaO (1: 0.75) NF ₃ 1.0 400 115 none Example 4 SnO, CaO (1: 0.5) NF ₃ 0.2 400 129 none Example 5 SnO, CaO (1: 0.5) NF ₃ 2.0 400 102 none Example 6 SnO, Ca (OH) ₂ (1: 0.5) NF ₃ 1.0 400 102 none Example 7 SnO, Ca (CO ₃ ) ₂ (1: 0.5) NF ₃ 1.0 400 88 none Example 8 SnO, MgO (1: 0.5) NF ₃ 1.0 400 130 none Example 9 SnO, SrO (1: 0.5) NF ₃ 1.0 400 89 none Example 10 SnO, La ₂ O ₃ (1: 0.5) NF ₃ 1.0 400 128 none Example 11 SnO, La ₂ O ₃ (1: 0.3) NF ₃ 1.0 400 120 none Example 12 SnO, La ₂ O ₃ (1: 0.75) NF ₃ 1.0 400 101 none Example 13 SnO, La ₂ O ₃ (1: 0.5) NF ₃ 0.2 400 131 none Example 14 SnO, La ₂ O ₃ (1: 0.5) NF ₃ 2.0 400 99 none Example 15 SnO, La (OH) ₃ (1: 0.5) NF ₃ 1.0 400 81 none Example 16 SnO, La ₂ (CO ₃ ) ₃ (1: 0.5) NF ₃ 1.0 400 76 none Example 17 SnO, CaO, La ₂ O ₃ (1: 0.3: 0.2) NF ₃ 1.0 400 122 none Example 18 SnO, CaO, La ₂ O ₃ (1: 0.2: 0.3) NF ₃ 1.0 400 118 none Comparative Example 1 SnO, KF NF ₃ 1.0 400 62 none Comparative Example 2 CaO NF ₃ 1.0 400 - has exist Comparative Example 3 La ₂ O ₃ NF ₃ 1.0 400 - has exist

The purifier of the gas containing nitrogen fluoride of the present invention facilitates its storage, handling and the like. In addition, by the method of purifying the gas containing nitrogen fluoride of the present invention, the reaction with diluent gas during the purification is performed. It does not cause the risk of sudden heat generation or the generation of harmful gases during post-treatment after purification, and does not cause an increase or blockage of pressure loss in the septic tank during purification, and it does not discharge NOx efficiently. The gas containing nitrogen fluoride can be purified.

Claims (10)

A purifier of a gas containing nitrogen fluoride, comprising at least one compound selected from oxides, hydroxides, carbonates, lanthanoids, hydroxides, and carbonates of tin oxide and alkaline earth metal as active ingredients. The method of claim 1, A purifier of a gas containing nitrogen fluoride, characterized in that the alkaline earth metal is magnesium, calcium or strontium. The method of claim 1, A purifier of a gas containing nitrogen fluoride, characterized in that the lanthanoid substance is lanthanum. The method of claim 1, A purifier of a gas containing nitrogen fluoride, characterized by containing 70% or more of the active ingredient in the purifier. The method of claim 1, A gas containing nitrogen fluoride, wherein the ratio of the number of atoms of tin included in the purification agent, the number of atoms of the alkaline earth metal derived from the active ingredient and the number of lanthanoids is 1: 0.1 to 2.0. Purifier of The method of claim 1, A purifier of a gas containing nitrogen fluoride, characterized by containing a metal fluoride as a forming aid together with the active ingredient. The method of claim 6, A purifier of a gas containing nitrogen fluoride, wherein the metal fluoride is potassium fluoride. The method of claim 1, A nitrogen fluoride-containing gas purifier, characterized in that the nitrogen fluoride is at least one selected from nitrogen trifluoride, dinitrogen tetrafluoride, dinitrogen difluoride, and dinitrogen hexafluoride. A purifier containing a gas containing a nitrogen fluoride, which is a toxic component, as an active ingredient containing one or more compounds selected from oxides, hydroxides, carbonates, lanthanoids, hydroxides and carbonates of tin oxide and alkaline earth metals under heating; A method for purifying a gas containing nitrogen fluoride, characterized by purifying by contacting. The method of claim 9, A method for purifying a gas containing nitrogen fluoride, wherein the contact temperature between the gas containing nitrogen fluoride and the purifying agent is 200 to 800 ° C.