KR102091728B1 - Retention type continuous digestion apparatus that removes hydrogen peroxide from spent sulfuric acid using activated carbon - Google Patents

Abstract

The present invention relates to a retention type continuous dissolution bath apparatus for removing hydrogen peroxide from waste sulfuric acid using activated carbon and, more specifically, to a retention type continuous dissolution bath apparatus for removing hydrogen peroxide from waste sulfuric acid using activated carbon, which dissolves the hydrogen peroxide included in the waste sulfuric acid generated from a wafer cleaning process of a semiconductor manufacturing process through an active carbon catalyst to purify the sulfuric acid. To this end, according to the present invention, the retention type continuous dissolution bath apparatus for removing the hydrogen peroxide included in the waste sulfuric acid generated from the semiconductor manufacturing process through a dissolution reaction of separating the hydrogen peroxide included in the waste sulfuric acid into water and hydrogen by using a catalyst comprises: a dissolution tank having a reception space formed therein to form a dissolution bath and a retention bath; a plurality of acid-resistant filtering and separation membranes installed on the inner wall surface of the dissolution tank at predetermined intervals to partition the reception space of the dissolution tank into a plurality of dissolution baths and retention baths, not passing the catalyst received in the dissolution baths, and passing the waste sulfuric acid; a filtering apparatus purifying the waste sulfuric acid, from which the hydrogen peroxide is removed, transferred from the retention baths; a collection hood collecting discharge gas generated by dissolving the hydrogen peroxide included in the catalyst and waste sulfuric acid received in the dissolution baths; and a wet filtering unit receiving the discharge gas from the collection hood to remove pollutant from the discharge gas.

Description

Retention type continuous digestion apparatus that removes hydrogen peroxide from spent sulfuric acid using activated carbon}

The present invention relates to a continuous continuous decomposition tank apparatus for removing hydrogen peroxide in sulfuric acid waste acid using activated carbon, and more specifically, hydrogen peroxide contained in sulfuric acid waste acid generated in a wafer cleaning process during a semiconductor manufacturing process through an activated carbon catalyst. The present invention relates to a continuous continuous cracking apparatus for removing hydrogen peroxide in sulfuric acid using activated carbon to decompose and purify sulfuric acid.

In the semiconductor manufacturing process, hydrogen peroxide (H ₂ O ₂ ) is a kind of commonly used oxidizing agent, and is always used with sulfuric acid (H ₂ SO ₄ ) to be used as a photoresist removal solution or an etching solution. Sulfuric acid waste acid accounts for more than 30-40%.

Since sulfuric acid waste acid has strong oxidizing properties, it must be removed to reduce hydrogen peroxide to favor storage and recovery recycling, and the general hydrogen peroxide treatment method is processed as follows.

(1) Heat decomposition: As shown in Equation 1 below, when heated to a temperature of 140 ° C or higher, hydrogen peroxide is rapidly decomposed to release oxygen gas. The most problematic drawback of this method is the risk of high temperature exothermic reactions.

(2) UV decomposition: When hydrogen peroxide molecules absorb UV rays with a wavelength of 3200 ~ 3800Å, the decomposition reaction proceeds. The drawback of this method is that other components in the solution may absorb ultraviolet rays, and thus the effect of absorbing hydrogen peroxide on ultraviolet rays is lowered. Therefore, the intensity of the ultraviolet light source must be strengthened, and other photochemical byproducts are likely to be generated, which is not preferable.

(3) Decomposition of nitric acid: Oxygen gas is released by generating decomposition reaction by adding nitric acid (HNO ₃ ) to a sulfuric acid solution containing hydrogen peroxide. This method is accompanied by a high exothermic temperature during the decomposition reaction, whereby sulfuric acid gas can be released, and further processing is required to remove nitric acid used as a catalyst for the reaction.

(4) Other organic or inorganic substances are added as a reducing agent to act with hydrogen peroxide. This method can control safety and reaction efficiency only by controlling the reaction temperature to an appropriate temperature. You should also consider whether or not to add treatment.

As described above, there is a need to develop a hydrogen peroxide removal device capable of increasing the removal efficiency while reducing the equipment and maintenance cost input when removing hydrogen peroxide in sulfuric acid waste acid.

Korean Registered Patent No. 10-1641959

The present invention has been devised to solve the above problems, and the activated carbon is introduced as a catalyst for removing hydrogen peroxide in sulfuric acid in stages in a decomposition tank divided into a plurality, but gradually increased by increasing the amount of activated carbon along the movement path of sulfuric acid. Providing a continuous continuous decomposition tank apparatus for removing hydrogen peroxide in sulfuric acid using activated carbon that can increase the removal rate due to decomposition reaction of hydrogen peroxide while reducing contamination or damage of activated carbon due to an increase in exothermic temperature. There is a purpose.

The present invention has the following features to achieve the above object.

In the present invention, a continuous continuous decomposition tank apparatus in which hydrogen peroxide in sulfuric acid sulfuric acid is removed through a decomposition reaction that is separated into water and oxygen by utilizing a catalyst in sulfuric acid waste acid containing hydrogen peroxide generated in a semiconductor process, is the continuous type The decomposition tank apparatus includes a decomposition tank in which an accommodation space is formed inside to form a decomposition tank and a storage tank; A plurality of spaced apart spaces are installed on the inner wall surface of the cracking tank so as to divide the receiving space in the cracking tank into a plurality of cracking tanks and storage tanks. A separator; A filtering device for carrying out purification by transferring sulfuric acid waste acid from which hydrogen peroxide has been removed from the storage tank; A collection hood for collecting the exhaust gas generated by the decomposition reaction of the catalyst contained in the decomposition tank and the hydrogen peroxide contained in the sulfuric acid waste acid; And a wet filtration unit that receives the exhaust gas from the collection hood and removes contaminants.

Here, the decomposition tank includes a first decomposition tank, a second decomposition tank, and a third decomposition tank, which are partitioned through an acid-resistant filtration separation membrane in the decomposition tank and are sequentially arranged adjacent to each other.

In addition, the first cracking tank, the second cracking tank, and the third cracking tank include a catalyst for removing hydrogen peroxide in sulfuric acid, but the catalyst has a specific surface area of 500 to 3000 m2 / g and is formed in a granular form with a size larger than 30 mesh. It is preferable to be impregnated with an iron salt containing iron oxide with activated carbon to be surface coated.

In addition, the first decomposition tank, the second decomposition tank and the third decomposition tank prevent bubbles from occurring in the air of sulfuric acid liquid particulates generated when bubbles are generated in the decomposition process between the catalyst and hydrogen peroxide in sulfuric acid and are destroyed when contacted with air. To prevent this, a shatterproof acid-resistant ball made of plastic, which has a specific gravity lower than that of sulfuric acid, is injected.

In addition, the acid-resistant filtration membrane is formed of an acid-resistant material that does not pass granular activated carbon, but only sulfuric acid waste acid.

According to the present invention, as the waste sulfuric acid waste acid is configured to be recycled as sulfuric acid, waste generated in the industry is recycled to resources to prevent environmental pollution and at the same time achieve resource saving.

In addition, hydrogen peroxide is removed according to the natural retention of sulfuric acid waste transport, thereby preventing a rapid reaction with activated carbon, thereby reducing contamination or damage of activated carbon.

In addition, since hydrogen peroxide is removed by a continuous continuous decomposition method, it is possible to remove hydrogen peroxide of sulfuric acid in large quantities by increasing the capacity of the decomposition tank or increasing the number of decomposition tanks, and additional chemicals are added by using activated carbon, which is a semi-permanent catalyst. Since it is not necessary, the maintenance cost and the management cost are significantly reduced.

1 is a view showing a schematic configuration of a continuous continuous decomposition tank apparatus according to an embodiment of the present invention.
Figure 2 is a block diagram showing the internal configuration and hydrogen peroxide removal process of the continuous continuous decomposition tank apparatus according to an embodiment of the present invention.

In order to explain the operational advantages of the present invention and the objects achieved by the practice of the present invention, the following describes preferred embodiments of the present invention and looks at them with reference to them.

First, the terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention, and singular expressions may include plural expressions unless the context clearly indicates otherwise. Also, in this application, the terms “include” or “have” are intended to indicate the presence of features, numbers, steps, actions, components, parts or combinations thereof described in the specification, one or more other It should be understood that features or numbers, steps, operations, components, parts or combinations thereof are not excluded in advance.

In describing the present invention, when it is determined that detailed descriptions of related well-known configurations or functions may obscure the subject matter of the present invention, detailed descriptions thereof will be omitted.

1 is a view showing a schematic configuration of a continuous continuous decomposition tank apparatus according to an embodiment of the present invention, Figure 2 is an internal configuration and hydrogen peroxide of the continuous continuous decomposition tank apparatus according to an embodiment of the present invention It is a block diagram showing the removal process.

Referring to the drawings, the residence type continuous decomposition tank apparatus 100 according to an embodiment of the present invention largely decomposes a tank 10 in which a receiving space is formed inside to form a decomposition tank 11 and a storage tank 12 ), A plurality of spaced apart on the inner wall surface of the decomposition tank 10 so as to divide the receiving space in the decomposition tank 10 into a plurality of decomposition tanks 11 and storage tanks 12, disassembled The catalyst accommodated in the tank 11 does not pass, and the sulfuric acid waste acid can pass through the acid-resistant filtration separation membrane 20, and the filtration device 30 for carrying out purification by transporting the sulfuric acid waste acid from which hydrogen peroxide has been removed from the storage tank 12 , The catalyst is accommodated in the decomposition tank 11 and the hydrogen peroxide contained in sulfuric acid waste acid is decomposed to collect the exhaust gas generated by the decomposition reaction and receives the exhaust gas from the capture hood 40 and the pollutant to receive the pollutants It consists of a wet filtration unit 50 to be removed.

Here, the decomposition tank 10 is formed with a receiving space so that the decomposition tank 11 and the storage tank 12 are formed, and a plurality of the decomposition tanks 11 and the storage tank 12 are respectively acid resistant filtration separation membrane 20 in the accommodation space. ).

In addition, the decomposition tank 10 is preferably made of a concrete material having acid resistance or formed of a material having excellent acid resistance as it must accommodate sulfuric acid waste acid.

The decomposition tank 11 is separated and divided into a plurality through the acid-resistant filtration membrane 20, and the acid-resistant filtration membrane 20 is a filterable membrane having acid resistance so that the sulfuric acid wastewater contained in the decomposition tank 11 can pass through. Is formed.

The catalyst or the shatterproof acid-resistant ball 60 accommodated in the decomposition tank 11 by the acid-resistant filtration separation membrane 20 cannot move from the decomposition tank 11 to the adjacent decomposition tank 11.

The reason why the decomposition tank 11 according to the present invention is formed in plural is that the hydrogen peroxide in the sulfuric acid waste acid is gradually removed while sequentially moving the plurality of decomposition tanks 11 in which sulfuric acid waste acid is sequentially partitioned, as well as the removal efficiency of hydrogen peroxide. This is to gradually increase the amount of the catalyst input in the order of the decomposition tank 11 along the movement path in order to increase the most.

That is, as shown in FIG. 1, when three decomposition tanks 11 are formed, 0.5 to 1 part by weight of activated carbon is added to the first decomposition tank 11a based on 100 parts by weight of sulfuric acid waste water, and the second decomposition tank When activated carbon is added in 1 to 2 parts by weight based on 100 parts by weight of sulfuric acid waste water (11b), activated carbon is added in an amount of 2 to 5 parts by weight based on 100 parts by weight of sulfuric acid waste water in the third cracking tank (11c), resulting in decomposition reaction It is possible to maximize the removal efficiency of hydrogen peroxide while controlling the temperature within a stable temperature where the catalyst is not contaminated or destroyed.

Therefore, it is possible to optimize the removal efficiency of hydrogen peroxide in the sulfuric acid waste water as well as induce a natural flow through the acid-resistant filtration membrane 20 without forcing separate separation tank movements and increase the input amount of the catalyst.

In addition, the catalyst to be introduced into each of the decomposition tanks (11a, 11b, 11c) is provided to remove hydrogen peroxide in sulfuric acid, and the catalyst has a specific surface area of 500 to 3000 m2 / g and is formed in a granular form with a size larger than 30 mesh. It is preferably activated carbon.

On the other hand, the storage tank 12 receives the sulfuric acid waste acid from which the hydrogen peroxide has been removed from the decomposition tank 11 through the acid filtration separation membrane 20, stores it for a certain time, and then delivers it to the filtration device 30 installed at the rear end. In order to transfer the sulfuric acid wastewater from the storage tank 12 to the filtering device 30, it may be delivered through a separate discharge pipe, and as shown in FIG. 1, the sulfuric acid waste acid exceeding a certain level on the wall surface of the storage tank 12 is filtered device The discharge dam 12a may be formed to be delivered to the 30 side.

Although schematically illustrated in FIG. 1, the discharge dam 12a is provided with a separate raising and lowering driving unit so as to adjust the amount or discharge rate of sulfuric acid waste acid delivered to the filtration device 30 as it moves up and down to the desired height. Can be configured.

On the other hand, the filtration device 30 is provided to perform additional physical or chemical purification process by transporting sulfuric acid waste acid from which hydrogen peroxide has been removed from the storage tank 12, and the filtration device 30 is removed in sulfuric acid waste acid from which hydrogen peroxide has been removed. It can be configured in various forms depending on the target.

In addition, a collection hood 40 is provided on the decomposition tank 11 or the storage tank 12 to capture the exhaust gas generated during the decomposition reaction of hydrogen peroxide in sulfuric acid and catalyst, activated carbon.

The exhaust gas collected by the collecting hood 40 is transferred to the wet filtration unit 50, and the wet filtration unit 50 removes contaminants in the exhaust gas.

The removal configuration of the wet filtration unit 50 may be formed in various forms depending on the removal rate of the pollutant or the object to be removed.

On the other hand, in the first decomposition tank 11a, the second decomposition tank 11b, and the third decomposition tank 11c, bubbles generated in the decomposition process between the catalyst and hydrogen peroxide in sulfuric acid are raised and destroyed when contacted with air. In order to prevent scattering of sulfuric acid liquid particulates in the air, a shatterproof acid resistant ball 60 made of plastic having a specific gravity lower than that of sulfuric acid waste acid is introduced, and these shatterproof acid resistant balls 60 are disposed on the upper front of each decomposition tank 11. It is preferable that it is sufficiently injected to cover the.

Hereinafter, various examples and experimental examples for removing hydrogen peroxide in sulfuric acid from the sulfuric acid through the retention type continuous cracking apparatus according to the present invention will be described.

First, two types of activated carbon were prepared for the test.

Example 1. Collection of sulfuric acid and preparation of activated carbon

As the sulfuric acid waste acid of the present invention, sulfuric acid waste acid including hydrogen peroxide generated in the semiconductor industry was used, and more specifically, sulfuric acid 60% by weight, hydrogen peroxide 5% by weight, and water 35% by weight were used. In addition, the activated carbon was prepared to have a specific mesh area of at least 950 m2 / g and a coal-based size of 30 mesh.

Example 2. Preparation of activated carbon impregnated with iron oxide

The activated carbon prepared in Example 1 was impregnated with iron oxide to prepare activated carbon. More specifically, the activated carbon prepared in Example 1 was first etched and oxidized in an acid solution. As an acid solution, 95% (v / v) sulfuric acid and 70% (v / v) nitric acid were prepared at a ratio of 3: 1, and activated carbon was immersed in the prepared acid solution at 25 ° C for 24 hours. After that, the activated carbon treated with the acid solution was repeatedly washed with distilled water to adjust the pH to neutral. The process of impregnating the neutralized activated carbon with iron oxide proceeded as follows.

Tri (III) iron nitrate (Fe (NO ₃ ) ₃ ㅇ 9H ₂ O) was added to ethanol to prepare a 3% by weight iron salt solution. Thereafter, the activated carbon was added to the iron salt solution, and the iron salt solution was put in an ultrasonic cleaner to vibrate for 10 minutes so that the iron salt solution was impregnated with the activated carbon. Thereafter, the activated carbon impregnated with the iron salt solution was heat treated at 100 ° C. for 1 hour to remove ethanol, and then heat treated at 400 ° C. for 4 hours to oxidize the iron salt to prepare activated carbon impregnated with iron oxide.

Experimental Example 1. Determination of the hydrogen peroxide decomposition time according to the amount of activated carbon

An experiment was conducted to confirm the decomposition time of hydrogen peroxide according to the amount of activated carbon or nitric acid. For this experiment, a retention type decomposition tank 11 made of an acid-resistant material was prepared, and 1 g, 2 g, 3 g, 4 g, and 5 g of activated carbon were respectively added to the retention type decomposition tank, and 100 g of sulfuric acid waste acid collected in Example 1 was prepared. Was poured into each retention type decomposition tank, and the number of bubbles generated was measured through a bubble collecting device, and this is shown in Table 1 below. On the other hand, when no more bubbles were generated, it was determined that the decomposition of hydrogen peroxide was completed and the decomposition completion time was confirmed.

Activated carbon input Experimental Example 1-1 Experimental Example 1-2 Experimental Example 1-3 Experimental Example 1-4 Experimental Example 1-5 Activated carbon 1 g 2g activated carbon Activated carbon 3 g Activated carbon 4 g Activated carbon 5 g Elapsed time (hour) Number of bubbles generated (pieces / minute) One 7 13 18 24 30 2 8 14 18 21 23 3 8 10 15 20 10 4 6 8 11 13 0 5 4 7 9 7 - 6 4 4 7 6 - 7 3 3 5 3 - 8 2 2 2 0 - 9 2 2 2 - - 10 2 One 2 - - Disassembly completion time (hours) 20 16 11 8 4

Referring to Table 1, it can be seen that as the amount of activated carbon increased, the decomposition completion time of hydrogen peroxide was shortened, and in Experimental Example 2-5, it was found that the decomposition completion time was 4 hours. When 1 g of activated carbon was added, the decomposition completion time was 20 hours, and the number of bubbles generated was 2 or less and maintained for 11 hours. Therefore, it was confirmed that as the input amount of activated carbon increased, the decomposition time was faster.

Experimental Example 2. Confirmation of heat generation comparison according to the amount of activated carbon

An experiment was conducted to confirm the heat generated during the decomposition of hydrogen peroxide according to the amount of activated carbon prepared in Example 1.

For this experiment, a retention-type decomposition tank 11 made of an acid-resistant material was prepared, and 1 g, 2 g, 3 g, 4 g, and 5 g of activated carbon were put in the retention-type decomposition tank, respectively, and each 100 g of sulfuric acid waste acid collected in Example 1 was prepared. It is shown in Table 2 below by measuring the temperature change over time after being poured into the residence type cracking tank.

division Activated carbon
input Temperature change Upon input 1 hours 3 hours 5 hours 10 hours Experimental Example 2-1 1 g 24 ℃ 24 ℃ 25 ℃ 26 ℃ 26 ℃ Experimental Example 2-2 2 g 24 ℃ 25 ℃ 26 ℃ 27 ℃ 26 ℃ Experimental Example 2-3 3 g 24 ℃ 25 ℃ 28 ℃ 30 ℃ 30 ℃ Experimental Example 2-4 4 g 24 ℃ 30 ℃ 32 ℃ 34 ℃ - Experimental Example 2-5 5 g 24 ℃ 33 ℃ 35 ℃ - -

Referring to Table 2, Experimental Examples 2-1 to 2-3 showed 30 ° C. or less until the end of the reaction after injection, and thus it was confirmed that exotherm was insufficient during the hydrogen peroxide decomposition process, whereas in Experimental Examples 2-4 and 2-5, It was confirmed that the exothermic temperature exceeded 30 ° C. In addition, when 3 g or more of activated carbon based on sulfuric acid waste acid was added, sulfuric acid due to damage to activated carbon was contaminated during the decomposition process, and it was found that sulfuric acid gas was generated, resulting in poor stability.

Through the measurement of the hydrogen peroxide decomposition time and the experiment example 2, the decomposition time is shortened, but the exothermic temperature is also increased. Therefore, it was confirmed that simply increasing the amount of activated carbon is inferior to hydrogen peroxide decomposition, and when less activated carbon is added, the decomposition time of hydrogen peroxide is too long to be effective.

Experimental Example 3. Divided hydrogen peroxide in stages by dividing activated carbon

In this example, an experiment was performed in which activated carbon was divided into steps to decompose hydrogen peroxide in sulfuric acid. This experiment was conducted using a continuous cracking tank connected to a retention cracking tank. More specifically, the retention type decomposition tank includes a filtration device capable of filtering activated carbon and is made of a tank made of acid-resistant material, and is continuously capable of continuously supplying and discharging sulfuric acid waste acid by connecting three retention type decomposition tanks. A type cracker was used. The three retention-type cracking tanks were scaled down to the first cracking tank 11a, the second cracking tank 11b, and the third cracking tank 11c, respectively, to produce a small size. It was put in differently.

The amount of activated carbon in each cracking tank was 1 g for the first cracking tank 11a, 2 g for the second cracking tank 11b, and 4 g for the third cracking tank 11c. Then, 100 g of sulfuric acid waste acid collected in Example 1 was poured into the first cracking tank 11a, and after 4 hours of hydrogen peroxide decomposition reaction, the activated carbon was filtered and the sulfuric acid waste acid of the cracking tank 1 was moved to the next cracking tank 2 Subsequently, a hydrogen peroxide decomposition reaction was performed. After the reaction in the decomposition tank 2 for an additional 4 hours, 4 g of activated carbon was moved to the decomposition tank 3 into which the hydrogen peroxide decomposition reaction was performed. The decomposition tanks having different amounts of activated carbon were each subjected to a step of decomposing hydrogen peroxide in sulfuric acid, and the decomposition times and temperature changes were measured in the same manner as in Experimental Examples 1 and 2, and the results are shown in Tables 3 and 4.

division Number of bubbles generated (pieces / minute) 1g of activated carbon
First cracking tank 2g of activated carbon
Second cracking tank 4g of activated carbon
Third cracking tank Initial input 7 1 hours 8 2 hours 8 3 hours 8 4 hours Transferred to the second cracker 10 5 hours 9 6 hours 8 7 hours 4 8 hours Transferred to the third cracker 8 9 hours 2 10 hours 0

division Temperature change Initial input 1 hours 3 hours 6 hours 9 hours First cracking tank with 1 g of activated carbon 24 ℃ 24 ℃ 25 ℃ - - Second cracking tank with 2 g of activated carbon - - - 27 ℃ - Third cracking tank with 4 g of activated carbon - - - - 30 ℃

Referring to Tables 3 and 4, it can be confirmed that the decomposition was completed within 10 hours when the decomposition of hydrogen peroxide in sulfuric acid was divided into three steps. Compared to the hydrogen peroxide decomposition times of Experimental Examples 1-1 to 1-3, it can be seen that the time was shortened, and through this, the amount of activated carbon was increased at a time when the content was lowered during decomposition of hydrogen peroxide in sulfuric acid. It can be seen that the method can reduce the hydrogen peroxide decomposition time.

On the other hand, although the hydrogen peroxide decomposition time was not shortened compared to Experimental Examples 1-4 and 1-5, sulfuric acid contamination and sulfuric acid gas by activated carbon generated in Experimental Examples 1-4 and 1-5 did not occur in Experimental Example 3, The exothermic temperature also shows 30 ° C. or less, confirming that it decomposes hydrogen peroxide in a stable state, and it can be seen that it is a method of more effectively removing hydrogen peroxide in sulfuric acid waste acid.

Experimental Example 4. Decomposition of hydrogen peroxide by dividing the activated carbon impregnated with iron in stages

In this experimental example, an experiment was conducted in which the activated carbon impregnated with iron oxide was divided into stages to decompose hydrogen peroxide in sulfuric acid. The experiment was carried out in the same manner as in Experimental Example 3, but instead of activated carbon, activated carbon impregnated with iron oxide prepared in Example 2 was added, and after the sulfuric acid was added, the beaker was changed at intervals of 3 hours. Accordingly, the decomposition time and temperature change are shown in Tables 5 and 6 below.

division Number of bubbles generated (pieces / minute) First cracking tank with 1 g of activated carbon impregnated with iron oxide 2nd cracking tank with 2 g of activated carbon impregnated with iron oxide Third cracking tank with 4 g of activated carbon impregnated with iron oxide Initial input 8 1 hours 9 2 hours 8 3 hours Transferred to the second cracker 12 4 hours 10 5 hours 9 6 hours Transferred to the third cracker 9 7 hours 3 8 hours 0 9 hours - 10 hours -

division Temperature change Initial input 1 hours 3 hours 5 hours 7 hours First cracking tank with 1 g of activated carbon impregnated with iron oxide 24 ℃ 24 ℃ - - - 2nd cracking tank with 2 g of activated carbon impregnated with iron oxide - - 26 ℃ 26 ℃ - Third cracking tank with 4 g of activated carbon impregnated with iron oxide - - - - 29 ℃

Referring to Tables 5 and 6, it can be confirmed that the decomposition was completed within 8 hours when the decomposition of hydrogen peroxide in sulfuric acid was divided into three stages. Compared to Experimental Example 3, it can be seen that the hydrogen peroxide decomposition time is shorter and the exothermic temperature is also less than 30 ° C., which is more effective. There was no contamination due to activated carbon damage, and sulfuric acid gas was not generated due to the low exothermic temperature.

As described above, the present invention forms a plurality of decomposition tanks 11 through the acid-resistant filtration separation membrane 20 in a continuous type, and gradually increases the input amount of the activated carbon, which is a catalyst, by controlling the heating temperature so as not to overheat and decomposes. It can be configured to maximize the reaction rate.

As described above, the present invention has been described with reference to one embodiment shown in the drawings, but this is only an example, and various modifications and equivalent other embodiments are possible from those skilled in the art. Will understand.

Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

Claims (5)

In the residual continuous decomposition tank apparatus in which hydrogen peroxide in sulfuric acid waste acid is removed through a decomposition reaction separated into water and oxygen by using activated carbon in sulfuric acid waste acid including hydrogen peroxide generated in a semiconductor process,
The residence type continuous decomposition tank apparatus 100
A decomposition tank 10 in which an accommodation space is formed inside to form a decomposition tank 11 and a storage tank 12;
A plurality of spaced apart spaces are installed on the inner wall surface of the decomposition tank 10 to divide the receiving space in the decomposition tank 10 into a plurality of decomposition tanks 11 and a storage tank 12, and the decomposition tank 11 ) Does not pass through the catalyst, and the sulfuric acid waste acid can pass through the acid-resistant filtration membrane 20;
A filtering device 30 for carrying out purification by transporting sulfuric acid waste acid from which hydrogen peroxide has been removed from the storage tank 12;
A collection hood 40 for collecting the exhaust gas generated by the decomposition reaction of the catalyst contained in the decomposition tank 11 and the hydrogen peroxide contained in the sulfuric acid waste acid; And
Includes; a wet filtration unit 50 to remove the pollutants by receiving the exhaust gas from the collecting hood 40;
The decomposition tank 11 is partitioned through an acid-resistant filtration membrane 20 in the decomposition tank 10, and is firstly arranged in a neighboring sequence, and then the second decomposition tank 11a, the second decomposition tank 11b, and the third decomposition. Including the tank (11c), the first cracking tank (11a), the second cracking tank (11b) and the third cracking tank (11c) includes a catalyst for removing hydrogen peroxide in sulfuric acid waste acid,
The catalyst is an activated carbon formed in a granular form having a specific surface area of 500 to 3000 m 2 / g and larger than 30 mesh, impregnated with an iron salt containing iron oxide, and surface-coated, and the first decomposition tank 11a contains 100 parts by weight of sulfuric acid waste water. Activated carbon is added in an amount of 0.5 to 1 part by weight, and activated carbon is added in an amount of 1 to 2 parts by weight based on 100 parts by weight of sulfuric acid waste water in the second cracking tank (11b), and 100 parts by weight of sulfuric acid waste water is used in the third cracking tank (11c). As a reference, 2 to 5 parts by weight of activated carbon is added, and the amount of the catalyst added while the sequential movement of the plurality of decomposition tanks 11a, 11b, and 11c in which the sulfuric acid waste acid is sequentially partitioned is the plurality of decomposition tanks 11a, 11b. , 11c) Residual continuous decomposition tank apparatus for removing hydrogen peroxide in sulfuric acid using activated carbon characterized in that it is slow in order.
delete delete According to claim 1,
The first cracking tank (11a), the second cracking tank (11b) and the third cracking tank (11c)
Bubbles generated in the decomposition process between the catalyst and the hydrogen peroxide in the sulfuric acid waste acid rise to prevent destruction of air in the air of sulfuric acid liquid particles generated by destruction upon contact with air. Residual continuous decomposition tank apparatus for removing hydrogen peroxide in sulfuric acid using activated carbon, characterized in that is).
According to claim 1,
The acid-resistant filtration membrane 20 is a continuous continuous decomposition tank device for removing hydrogen peroxide in sulfuric acid using activated carbon, characterized in that it is formed of an acid-resistant material that does not pass granular activated carbon but passes sulfuric acid waste acid.

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