JPH02275706A - Method for recovering argon - Google Patents

Abstract

PURPOSE:To recover high purity argon with high efficiency by removing ultrafine dust in a gas composition, bringing the resultant gas composition into contact with a catalyst, reacting hydrogen and carbon monoxide in the with oxygen, burning the gas, adsorbing and removing components other than the argon. CONSTITUTION:A waste gas from a furnace using argon is passed through coolers (2a) and (2b) and dust removing devices (3a) and (3b) and led to a dust removing step 8 to remove ultrafine dust. The resultant gas is then led to a concentration regulation step 13 and a combustion step 14. Insufficient oxygen is subsequently introduced to regulate the quantity of oxygen and the obtained recovered gas is brought into contact with a catalyst filled in a catalyst cylinder (14c) and burned to convert hydrogen and carbon monoxide into water and carbon dioxide. The gas after completing the combustion step is then passed through a cooler 15, a temperature regulating passage 17, etc., and led to an absorption step 19 to remove impurity components, such as nitrogen, oxygen, water, carbon dioxide, etc., in the gas. Thereby, the high purity argon can be recovered.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for recovering argon, particularly for bottom bubbling (BB) in continuous casting (CC) furnaces, vacuum degassing (RH) furnaces, and converters in steel plants. ), argon-oxygen blowing (
This article relates to the Knob method for recovering argon used in AOD (AOD) furnaces and the like from its exhaust gas with high efficiency.

(Prior Art) Argon has traditionally been widely used in the above-mentioned steel mill furnaces and other devices that require inert gas.The argon discharged from these devices contains various impurities. , e.g. hydrogen, nitrogen.

In addition to various gases such as oxygen, acid oxides, carbon dioxide, and carbon dioxide, it contains dust of various sizes, so when reusing argon in exhaust gas, it is necessary to remove the various impurities mentioned above and recover the argon. There is a need to.

Various proposals have been made to recover the above-mentioned argon. For example, in JP-A-59-152210, the exhaust gas mainly composed of argon emitted from the AOD furnace JJII is brought into contact with a catalyst to selectively burn hydrogen, and then the gaseous components except argon are adsorbed on an adsorbent. JP-A No. 60-204608 describes a method for recovering argon by contacting a catalyst with a component having low adsorption selectivity, such as hydrogen, in the same way as above. Supplemental oxygen is described.

Furthermore, JP-A No. 60-239309 discloses that carbon monoxide, carbon dioxide, and nitrogen are adsorbed using a theolite molecular sieve and carbon molecular sieve as adsorbents, and that part of the desorbed gas of the adsorbent is removed in an adsorption process. A method is described in which the amount of argon recovered is increased by sending the argon gas to the adsorption tower after the completion of the adsorption process, and sending argon gas of la degree higher than the raw material gas discharged from the adsorption tower to another adsorption tower in the adsorption step.

In addition, impurities such as hydrogen and carbon monoxide in a gas composition mainly composed of argon are brought into contact with a catalyst together with oxygen and burned, and then separated from the argon or easily adsorbed as water or carbon dioxide. Various methods of removal have been proposed.

[Problem to be solved by the invention]

However, with the argon recovery devices (methods) currently in practical use and the various proposals mentioned above, it is difficult to remove dust as impurities in the exhaust gas using a roll winding system, a water washing tower, or a water washing tower.
The dust in the exhaust gas is reduced to several mg/* using Venturi scrubbers, etc.
The extremely fine dust of 1 hum was not removed. At each step of the recovery operation, exhaust gas containing such fine dust is collected.
In particular, if introduced into the upper stage where a catalyst is used, it may cause clogging or act as a catalyst poison, which may impede long-term continuous operation of the recovery equipment.

In addition, when exhaust gas contains large amounts of hydrogen, carbon monoxide, etc., if these are brought into contact with the catalyst as they are with oxygen, a large amount of reaction heat will be generated due to combustion, and the temperature will rise above the heat-resistant temperature of the catalyst. To prevent this excessive temperature rise, the catalyst was divided into multiple stages or a ring was attached to some of the gases, but exhaust gas conditions were not sufficiently controlled. It wasn't.

Furthermore, in order to improve the yield of recovered argon,
In the above-mentioned Japanese Patent Application Laid-Open No. 60-239309, it is stated that a desorption gas containing argon at a higher concentration than the raw material gas is introduced into the adsorption tower in the adsorption process. It does not produce high concentrations of deoxidized gas, and even if it does,
Due to the pressure change in the adsorption tower during desorption and the characteristics of the vacuum pump used for desorption, when such a highly concentrated gas is introduced into the adsorption tower in the adsorption process, the pressure and flow rate inside the adsorption tower in the adsorption process will increase. The balance of temperature etc. may be disrupted, causing confusion in the adsorption front and deteriorating the adsorption efficiency.

Furthermore, when the adsorption step is performed in a pressurized PSA, a compressor for pressurizing the exhaust gas and the power cost for the compressor are required, which also causes a deterioration of the recovery unit.

On the other hand, as mentioned above, different types of adsorbents have been used to improve the adsorption capacity for adsorbing impurity components, but it cannot be said that they are still sufficiently effective. .

Therefore, the present invention solves the problems of the prior art described above, and
Our goal is to provide an argon recovery method that can recover argon with high efficiency and high purity.

[Means to solve the problem]

In order to achieve the above-mentioned object 1, the present invention provides a method for recovering argon from a gas composition containing argon as a main component, in which very fine dust in the gas composition is collected using a dust collector. In the dust removal step, the gas composition after dust removal is brought into contact with a catalyst to remove hydrogen and/or
or a combustion process in which carbon monoxide and oxygen in the gas composition and/or oxygen supplied from the outside are reacted and burned;
and an adsorption step in which components other than argon in the gas composition are adsorbed and removed by a plurality of adsorbers that are selectively used. A dust removal process in which fine dust is removed by a dust collector, the content of hydrogen, carbon monoxide, and oxygen in the gas composition after dust removal is measured, and the measurement results are calculated to determine the content of hydrogen and/or monoxide in the gas composition. A concentration adjustment process in which the amount of oxygen required to burn carbon is calculated, the amount of oxygen is compared with the amount of oxygen contained in the gas composition, and if necessary, a predetermined amount of oxygen is supplied from outside, after the concentration is adjusted. When bringing the gas composition into contact with a catalyst to cause hydrogen and/or carbon monoxide in the gas composition to react with oxygen in the gas composition and/or oxygen supplied from the outside to cause combustion, the hydrogen and/or Alternatively, the oxygen supplied from the outside is divided and supplied immediately before each stage of a catalyst that is divided into multiple stages according to the carbon monoxide concentration, and then brought into contact with the catalyst, or the gas composition after combustion is A combustion step in which the raw gas composition is circulated to dilute it and brought into contact with a catalyst to be combusted, and an adsorption step in which components other than argon in the gas composition are adsorbed and removed by a plurality of adsorbers that are selectively used. The present invention provides a method for recovering argon characterized in that a storage tank for storing the gas composition is provided before the dust removal process and before the adsorption process, and the gas composition introduced into the dust removal process and the adsorption process is A part of the exhaust gas discharged from the adsorption step is returned to the storage (a) disposed before the adsorption step to join the gas composition, and is introduced into the adsorption step again. To provide a method for recovering argon, characterized in that the pre-eye treatment in the adsorption step is performed by a pressure swing method under atmospheric pressure or reduced pressure, and the dust collector used for switching the dust removal step is an electric precipitator. It is.

[For production]

As mentioned above, 0°01-1 contained in the gas composition
By removing the ultrafine dust of am, it is possible to prevent clogging in the process using the catalyst and preventing it from acting as catalyst poison. In addition, the dust collector can be cleaned by configuring it so that it can be used interchangeably.

Reproduction, maintenance, etc. can be easily performed. In particular, by using the above dust collector as an electric dust collector that uses static electricity,
Even extremely fine dust can be removed with high efficiency.

Furthermore, the amount of hydrogen, carbon monoxide, and oxygen in the gas composition is measured, and the insufficient amount of oxygen is replenished, and the number of catalyst stages to be contacted and the amount of gas to be circulated are adjusted according to the amount. Accordingly, deterioration of the catalyst due to excessive temperature rise can be prevented while obtaining the necessary catalytic action.

Moreover, by arranging a storage tank before the dust removal process and the adsorption process and reducing the amount of gas composition introduced to 81M, each process can be performed in a stable state at all times.

In particular, by returning a portion of the exhaust gas discharged from the adsorption step to the storage tank preceding the adsorption step, argon in the exhaust gas can also be efficiently recovered. In addition, by performing this adsorption step under atmospheric pressure or reduced pressure, equipment such as a compressor and power costs are unnecessary.

〔Example〕

Hereinafter, the present invention will be explained in more detail based on an embodiment shown in FIG.

First, the exhaust gas discharged from the exhaust gas generation sources 1a, 2b, . Blower 4a, 4b via 3a, 3b, ...
,... or sucked into a vacuum pump, etc. Atmospheric discharge systems 5a, 5b, . . . branch from the argon recovery system on the discharge side of the blowers 4a, 4b, . In this way, popular release systems 5a, 5b,...
・By providing exhaust gas generation sources 1a, l of each furnace etc.
b,...'s (・ni karma state).

Switching valve 6a, 6b, depending on argon usage and deafness.
... can be operated to release exhaust gas that does not require recovery operations, without diluting the exhaust gas containing argon (hereinafter referred to as recovery gas) introduced into the argon recovery system. Therefore, the burden on the argon recovery system can be reduced and the argon recovery rate can be improved.

The recovered gas discharged from the blowers 4a, 4b, . . . is temporarily stored in a gas holder (storage tank) 7.

This gas holder 7 is a source of exhaust gas, a, b.

It is set to an appropriate capacity depending on the operating method and amount of gas discharged, and may be omitted if a certain amount of recovered gas is continuously generated.

The recovered gas in the gas holders is sucked into the blower 10 via the first dust remover 9 of the dust removal step 8 at a predetermined flow rate.

This first dust remover 9 removes several mg/Tr of dust from the recovered gas.
The conventional equipment such as a roll winding type, water washing tower, venturi scrubber, etc. is used to reduce the amount of water to about I'. It should be noted that the recovered gas becomes clear and the exhaust gas generation R1a, l
If the dust removers [3a, 3b, . . . attached to the dust removers 3a, 3b, .

The recovered gas discharged from the blower 10 is introduced into the second dust collectors 12a, 12b, which are selectively used by opening and closing the switching valves IIa, ilb, 11c, 1, d, and dust removal is carried out. This second dust collector 2a12b is used to have the function of removing very fine dust of about 0.01 to 1 in the recovered gas. As this type of dust collector, for example, a micron filter such as a hollow fiber membrane or an electric dust collector can be used. In particular, pressure loss can be reduced by using a vomiting dust collector that uses static electricity to remove extremely fine dust. In addition, by providing a plurality of second dust collectors 2a, 12b and using them selectively via the switching valves 11a, 11b, 11c, and lid, removal and regeneration of collected dust and maintenance work can be performed while operating the recovery line. This can be done rarely and enables long-term continuous operation. Depending on the internal structure of this dust collector, only the dust collecting electrode plate portion may be switched for use.

The recovered gas after dust removal is introduced into the next concentration 1χJ adjustment step 13 and combustion step 14, where it is converted into hydrogen and carbon monoxide contained in the recovered gas, or into water and carbon dioxide, which are easily adsorbed and removed. First, in the concentration, 'l,'j adjustment process 13, each concentration is determined by the oxygen analyzer 13a, hydrogen analyzer 31-+carbon monoxide analyzer 13c, and...
By measuring the flow rate of the recovered gas with the flow Qil'13d, the respective amounts of oxygen and hydrogen carbon monoxide in the recovered gas r11 are calculated. This calculation result is calculated by a calculation means 13e such as a microcomputer, and the amount of oxygen required to burn hydrogen and/or carbon monoxide is calculated. Then, when compared with the amount of oxygen in the recovered gas, if this is insufficient, the supply oxygen flow rate controller 13 f and the supply oxygen flow m + i
A predetermined amount of oxygen or air is introduced into the recovered gas from an oxygen supply device 13h consisting of a u1 control valve 13g.

It is preferable to supply a slightly larger amount of 1% oxygen in order to achieve complete combustion of hydrogen and/or carbon monoxide. It is desirable to add so that the residual amount of oxygen is on the order of several hundred to several thousand pl)ffl.

On the other hand, the combustion process 14 includes a heat exchanger 14a and a heater 14.
The recovered gas, whose temperature has been raised to a predetermined temperature in step b and whose oxygen content has been adjusted in the concentration adjustment step 13, is brought into contact with the catalyst filled in the catalyst cylinder 14C and burned, oxidizing hydrogen and carbon monoxide to form water and Carbon dioxide.

This combustion step 14 can be carried out in the -stage catalyst cylinder if the amount of hydrogen or carbon monoxide in the recovered gas is small, but if the amount is large, It is preferred to use the combustion process shown in 30.40.

The combustion step 30 shown in FIG.
Alternatively, it is applied when the amount of carbon monoxide is large and the amount of oxygen is small, and the catalyst cylinders 31a are arranged in multiple stages.

31b, . . . and each catalyst cylinder 31a3.
Before and after 1b, . . . , the same oxygen supply amounts R32a, 32b, . . . , coolers 33a, 33b, .
. . , bypass paths 34a, 34b, . . . are provided. In this combustion step 30, the amount of oxygen supplied calculated in the concentration adjustment step 13 described above is divided according to the number of stages of catalyst cylinders, and the amount of oxygen supplied in the above-described concentration adjustment process 13 is divided according to the number of stages of catalyst cylinders 31a.

By supplying the recovered gas immediately before 31b, . . . , the amount of combustion in each catalyst cylinder 3, a, 31b, . . . is reduced and heat generation is suppressed. In addition, the cooler 33a,
33b,... and the bypass path 34a.

34b, . . . are the front catalyst cylinders 31a, 31b, .
・This is to adjust the temperature of the recovered gas heated in step 1 and send it to the next stage catalyst cylinder. In addition, with this configuration, the amount of hydrogen and/or carbon monoxide in the recovered gas fluctuates and the amount of hydrogen and/or carbon monoxide decreases, making it difficult to combust sufficiently even with only the front several stages of catalyst cylinders. If possible, oxygen may be supplied only to these catalyst cylinder portions, and the recovered gas after completion of combustion may be led out to the next step through the bypass paths 34a, 34b, . . . .

The combustion process 40 shown in FIG.
Or, it is applied when the content of carbon monoxide is high and the content of oxygen is high, and the same coolers 42a, 42b, ... and bypass paths 43a, 43
A combustion system 44 having four water separators, a circulation blower 45, a blower discharge pressure control mechanism 46, etc. A circulation system 48 having a circulation flow rate control mechanism 47 and the like is provided.

This circulation system 48 is operated in response to the calculation result of the concentration adjustment step 13, and is operated in response to the calculation result of the concentration adjustment step 13, and the catalytic cylinder 41a.

41b, . . . , the recovered gas after combustion is sucked by the circulation blower 45, and the circulating gas whose pressure and flow rate are controlled by the blower discharge pressure control mechanism 46 and the circulation flow rate control mechanism 47 is recovered. It is introduced in the line immediately before the heat exchanger 14a. As a result, the catalyst cylinders 41a, 41b,
It is possible to dilute the recovered gas introduced into the reactor to reduce the concentration of hydrogen and/or carbon monoxide to a predetermined value or less, thereby preventing overheating of the catalyst. Note that if the calculation result of the concentration adjustment step 13 shows that the amount of hydrogen and/or carbon monoxide is small, this circulation system 48 can be stopped, and if the calculation result of the concentration adjustment step 13 shows that the amount of oxygen is small, can perform the combustion of hydrogen and/or carbon monoxide by supplying oxygen in the same manner as described above.

Returning to FIG. 1, the combustion process 14 configured as described above
The recovered gas is sent to the cooler 15. The recovered gas is introduced into the heat exchanger 14H via a temperature adjustment path 17 having a bypass path 16, and heats the recovered gas before being introduced into the combustion step 14, and the temperature of the recovered gas is lowered before being introduced into the gas holder 18 arranged before the adsorption step. be done. This gas holder 18, similar to the gas holder 7 placed before the dust removal process 8 described above, has the function of adjusting the flow rate of the recovered gas introduced into the latter adsorption process, and is a balloon or water seal type. A holder can be used, and its internal pressure is several tens to hundreds of mm.
It is kept at Aq. If this internal pressure is increased, the burden on the blower 10 and the vacuum pump for the adsorption process described later will increase, and the power consumption will increase, so it is desirable to keep it as low as possible.

One adsorption process for adsorbing and removing impurity components, ie, nitrogen, oxygen, water, carbon dioxide, etc. in the recovered gas stored in the gas holder 18, involves the use of three adsorption towers 20a and 20b.
, 20c;
20b, 20c are respective switching valve groups 21, 2, . . .
By switching on and off and operating the vacuum pump 22, adsorption is carried out by alternately repeating each stage of suction n = - next regeneration - vacuum drawing - barge regeneration - next charging pressure - secondary charging in each tower. do. That is, when the first column 20a is in the adsorption stage, the second column 20a is in the adsorption stage.
The column 20b is in the stage of primary charging and secondary charging, the third column 20c is in the stage of primary regeneration → vacuum regeneration → purge 1, and when the second column 20b moves to the adsorption stage, the first The column 20a moves to the stage of primary regeneration, vacuum regeneration, and purge regeneration, and the third column 20c moves to the stage of primary charging=secondary charging.

Note that one adsorption step may be performed using another adsorption method, such as a two-unit P
Although adsorption can be carried out using SA or the like or under pressure, in addition to vacuum regeneration using the vacuum pump 22 as described above, in addition to the vacuum regeneration using the vacuum pump 22, the recovered gas (hereinafter referred to as product gas) after impurities have been removed by adsorption is By performing purge regeneration in which the adsorbent is introduced into the adsorption tower from the outlet end of the adsorption tower to regenerate the adsorbent, the adsorbent can be regenerated more reliably.

In addition, by performing the suction operation at atmospheric pressure or reduced pressure (by suction by the product gas blower described later), the compressor for pressurizing the recovered gas introduced into the adsorption tower can be omitted, and its power cost can also be reduced. This will help reduce costs.

The adsorbents filled in the adsorption towers 20a, 20b, and 2Oc include a desiccant that mainly adsorbs water, an X-based synthetic zeolite that mainly adsorbs carbon dioxide, carbon molecular sieves that mainly adsorb oxygen, and a desiccant that mainly adsorbs carbon dioxide. It is preferable to use an appropriate amount of 5A-based zeolite that adsorbs 5A-type zeolite in a layered manner. The amount and proportion of the adsorbent used can be optimally determined according to the exhaust gas composition from the exhaust gas generation source.

Exhaust gas (hereinafter referred to as desorption gas) generated by regeneration of the adsorption towers 20 a , 20 b , and 20 c is sucked and discharged by the vacuum pump 22 . As the vacuum pump 22, it is preferable to use a water ring type vacuum pump or a water injection Roots type vacuum pump in view of the return gas, which will be described later. The desorption gas from the vacuum pump 22 is introduced into the water separator 23 and is discharged after separating the water. The separated water can be circulated to the vacuum pump 22 by the pump 24.

Further, in this adsorption step, a gas return circuit 25 is provided for returning the desorption gas discharged from the adsorption tower in the vacuum and purge regeneration stage to the gas holder 18. That is, the desorption gas led out of the water separator 23 is divided into two parts, one of which is discharged into the atmosphere from the muffler 27 via the exhaust valve 26, and the other is returned to the gas holder 18 from the return pipe 25b via the return valve 25a. It will be done.

The amount of returned gas is the argon concentration in the recovered gas.

It is appropriately set depending on the argon recovery rate in the entire system, desired product gas purity, etc. For example, recovered gas]
By returning and circulating the desorption gas 112°8 as a return gas, the argon recovery rate of the entire system was increased to 8.
It is possible to increase the rate to 0% or higher.

The high-purity argon thus recovered is sent to a consumer at an appropriate pressure by a product gas blower 28.

The amount of return gas can be adjusted by adjusting the opening degrees of the exhaust valve 26 and the return valve 25a and adjusting the opening/closing time. Also, whether it is necessary to increase the capacity of the adsorption tower by returning a portion of the desorbed gas is not a problem because the effect of improving the argon recovery rate greatly exceeds the increase in equipment cost.

Furthermore, the above-mentioned return gas can be returned to the adsorption tower inlet, but the desorption gas derived from the PSA has fluctuations in pressure and flow rate due to the characteristics of the vacuum pump as described above, and the vf of the adsorption tower Since the composition of the desorption gas differs depending on the state of the stage, by returning the return gas to the gas holder as described above, the gas introduced into the PSA can be kept in a stable state, and the efficiency can be increased without causing confusion in the adsorption front. This makes it possible to perform good adsorption removal.

As a result of processing 36NTff'/h of raw material exhaust gas containing 35.8% argon supplied from a holder in a steelworks using the apparatus shown in FIG. Argon, 0. 33
N-m'/h was obtained, and the recovery rate of the entire system was 80%. The flow rate and composition of each gas at this time were measured at fixed points fl11 indicated by symbols A-M in FIG. 1, and the results are shown in the following table.

As shown in this result, the argon concentration at the PSA inlet (G) is 18.7%, and the gas LM amount is 110.6%.
Nm/h, which was approximately 3.1 times the raw material exhaust gas amount of 35°4 Nm'/h. Furthermore, the average concentration of argon in the exhaust gas (J) is 10.3%.

The amount is 100.27 Ngo/h, of which 75
．． Return 2 Nm/h to PSA, 25. 7Nm
'/11 became popular.

Further, nitrogen as an impurity in the product argon was 800 ppm or less, and oxygen was 200 ppm or less. i.e. nitrogen, oxygen in the PSA stage.

Carbon dioxide and moisture can be removed, and the power consumption of this PSA section is approximately 0. 6kwII/Nrr? It was Ar.

It should be noted that the method of the present invention is not limited to the recovery of argon from steelwork exhaust gas as described above, but can of course also be used for recovery of argon from welding argon exhaust gas and recovery of inert gases other than argon. It is.

〔Effect of the invention〕

As explained above, the present invention removes ultrafine dust of 0.01 to 1 um contained in a gas composition, thereby preventing clogging in a process using a catalyst or acting as a catalyst poison. This enables long-term continuous operation. In addition, since the dust collectors are switched and used, cleaning, regeneration, maintenance, etc. of the dust collectors can be easily performed, and continuous operation can be performed under optimal conditions at all times. In particular, by using an electric dust collector that uses static electricity as the dust collector, even extremely fine dust can be removed with high efficiency while keeping pressure loss low.

Furthermore, the amount of hydrogen, carbon monoxide, and oxygen in the gas composition is determined by δp1, and the insufficient amount of oxygen is replenished, and the number of catalyst stages to be contacted and the amount of gas to be circulated are adjusted according to the amount. By doing so, it is possible to prevent deterioration of the catalyst due to excessive temperature rise while obtaining the necessary catalytic action, and also to reduce the amount of catalyst replacement.

In addition, by arranging a storage tank before the dust removal process and the adsorption process and adjusting the amount of gas composition introduced, each process can be performed in a stable state at all times, allowing efficient recovery. . In particular, by returning a portion of the exhaust gas discharged from the adsorption process to the storage tank before the adsorption process, the argon in the exhaust gas can be recovered, and the gas can be introduced at a uniform concentration within the storage tank to the extent that it is adsorbed. Therefore, the adsorption process can be performed in a stable state. In addition, this sucking i?
By performing the -L step at atmospheric pressure or reduced pressure F, equipment such as a compressor and power costs are not required, and the original 11th position can be improved.

Further, by combining adsorbents in the adsorption treatment as described above, each impurity component can be efficiently adsorbed and removed, and the recovery rate of argon can be improved.

Therefore, the recovery efficiency of argon in a steelworks or the like can be greatly improved, the cost of argon can be reduced, and it can even contribute to the cost reduction of the entire steelmaking industry.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing one embodiment of the present invention, and FIGS. 2 and 3 are system diagrams showing other embodiments of combustion. la, lb...Exhaust gas generation source 7,18・Gas holder 8...Dust removal process 13...Concentration adjustment process 14.30.40...Combustion process 1-4C...
Catalyst cylinder 19...Adsorption process 20a, 20b20
c...Adsorption tower 25...At the time of gas return circuit Applicant: Hiki Sanso Co., Ltd. Agent Patent attorney Thu
Part of the door - Hiko 7/ (1,. Koshin)

Claims (1)

[Claims] 1. A method for recovering argon from a gas composition containing argon as a main component, including a dust removal step of removing ultrafine dust in the gas composition with a dust collector, and a step of removing the gas composition after dust removal. A combustion process in which hydrogen and/or carbon monoxide in the gas composition are reacted with oxygen in the gas composition and/or oxygen supplied from the outside by being brought into contact with a catalyst, and argon in the gas composition is reacted with the oxygen supplied from the outside. A method for recovering argon, comprising an adsorption step of adsorbing and removing other components using a plurality of adsorbers that are selectively used. 2. In a method for recovering argon from a gas composition containing argon as a main component, a dust removal step of removing ultrafine dust in the gas composition using a dust collector, hydrogen and carbon monoxide in the gas composition after dust removal. The amount of oxygen contained in the gas composition and the amount of oxygen contained in the gas composition are calculated by calculating the measurement results and calculating the amount of oxygen necessary to burn hydrogen and/or carbon monoxide in the gas composition. A concentration adjustment step in which a predetermined amount of oxygen is supplied externally if necessary, and the gas composition after the concentration adjustment is brought into contact with a catalyst to adjust the gas composition with hydrogen and/or carbon monoxide in the gas composition. In order to cause the oxygen in the substance and/or the oxygen supplied from the outside to react and burn, the catalyst is divided into multiple stages depending on the concentration of hydrogen and/or carbon monoxide, and the catalyst is heated immediately before each stage of the catalyst. A combustion process in which oxygen supplied from the outside is supplied in parts and then brought into contact with a catalyst, or the gas composition after combustion is circulated to dilute the raw gas composition and brought into contact with a catalyst to be combusted;
and an adsorption step of adsorbing and removing components other than argon in the gas composition using a plurality of adsorbers that are selectively used. 3. A storage tank for storing the gas composition is provided before the dust removal step and before the adsorption step, and the amount of the gas composition introduced into the dust removal step and the adsorption step is adjusted. The method for recovering argon according to 1 or 2. 4. A part of the exhaust gas discharged from the adsorption step is returned to a storage tank disposed before the adsorption step to join the gas composition, and is introduced into the adsorption step again. Argon recovery method described. 5. Claim 1, wherein the adsorption treatment in the adsorption step is performed by a pressure swing method under atmospheric pressure or reduced pressure.
Or the argon recovery method described in 2. 6. The argon recovery method according to claim 1 or 2, wherein the dust collector used for switching the dust removal step is an electric dust collector.