TWI910455B - Processing system and processing method for processing piranha solution and preparing calcium sulfate - Google Patents

Abstract

A processing system and a processing method for processing a piranha solution and preparing calcium sulfate are provided. The processing system includes: a liquid mixing reaction unit, a piranha solution supply unit, a calcium carbonate solution mixing and supply unit, and a reaction liquid reflux unit. The piranha solution supply unit supplies a piranha solution or a piranha dilute solution into the liquid mixing reaction unit. The calcium carbonate solution mixing and supply unit supplies a calcium carbonate solution to the liquid mixing reaction unit for mixing and reacting with the piranha solution or the piranha dilute solution, thereby generating a reaction liquid containing a reaction product. The reaction product is calcium sulfate di-hydrate. The reaction liquid reflux unit filters and purifies the reaction liquid, so that the reaction product is separated from the reaction liquid, and the reaction liquid reflux unit further forms a reflux liquid, which is refluxed to the liquid mixing reaction unit.

Description

Treatment system and method for treating piranha solutions and preparing calcium sulfate

This invention relates to a system for treating piranha solutions, and more particularly to a system and method for treating piranha solutions and preparing calcium sulfate dihydrate.

Piranha solution can be a liquid used, for example, in semiconductor manufacturing processes (such as substrate cleaning). In existing technologies, after the process is complete, the waste liquid from piranha solution is primarily diluted with large amounts of water and stored in a concentrated manner. This leads to the problem of difficulty in timely handling of large quantities of stored waste liquid, and may pose risks of explosion or liquid leakage. Furthermore, the waste liquid from piranha solution itself does not have industrial application value.

Therefore, the inventor felt that the above-mentioned defects could be improved, so he devoted himself to research and applied scientific principles, and finally proposed an invention with a reasonable design that effectively improves the above-mentioned defects.

The technical problem to be solved by this invention is to provide a treatment system and method for treating piranha solutions and preparing calcium sulfate, addressing the shortcomings of existing technologies.

To solve the aforementioned technical problems, one of the technical solutions adopted by this invention is to provide a treatment system for processing piranha solution and preparing calcium sulfate dihydrate, comprising: a liquid mixing reaction unit; a piranha solution supply unit configured to supply a piranha solution or a piranha dilute solution to the liquid mixing reaction unit; a calcium carbonate solution mixing supply unit configured to supply a calcium carbonate solution to the liquid mixing reaction unit for mixing and reaction with the piranha solution or the piranha dilute solution, thereby producing a reaction liquid containing a reaction product; wherein the reaction product is calcium sulfate dihydrate; and a reaction liquid reflux unit configured to filter the reaction liquid. The reaction mixture is purified to precipitate the reaction product from the reaction liquid, and the reaction liquid reflux unit further forms a reflux liquid, which is refluxed back to the piranha liquid supply unit for dilution of the piranha liquid. In the reflux liquid, the unfiltered calcium sulfate dihydrate crystals can be used as seed crystals, first refluxed into the piranha liquid supply unit, and then entered into the liquid mixing reaction unit along with the diluted piranha solution.

Preferably, the piranha solution provided by the piranha solution supply unit is a liquid used in the semiconductor manufacturing process or a waste liquid generated after the process is completed; and the piranha dilution solution is a solution of the piranha solution diluted with water.

Preferably, in the liquid mixing reaction unit, the calcium carbonate ( _CaCO3 ) contained in the calcium carbonate solution reacts with the sulfuric acid ( _{H2SO4 )} contained in the piranha solution to produce the reaction liquid containing the reaction products.

Preferably, the first volumetric flow rate of the piranha solution introduced into the liquid mixing reaction unit is 0.0007~0.0014 ^m³ /s, and the second volumetric flow rate of the calcium carbonate solution introduced into the liquid mixing reaction unit is 0.0004~0.0008 ^m³ /s.

Preferably, the processing system further includes: a hydrogen peroxide removal unit configured to receive the reflux liquid returned by the reaction liquid reflux unit, and to remove hydrogen peroxide from the reflux liquid or reduce the concentration of hydrogen peroxide in the reflux liquid; and then, to return the reflux liquid to the piranha liquid supply unit.

Preferably, after the piranha solution and the calcium carbonate solution in the liquid mixing reaction unit react, a reaction gas containing carbon dioxide is also formed.

Preferably, the processing system further includes: a carbon dioxide purification unit configured to receive the reaction gas and purify the reaction gas to form a purified gas containing high-purity carbon dioxide.

Preferably, the processing system further includes: a carbon dioxide absorption unit configured to receive the reaction gas and absorb the reaction gas to form an inorganic substance. The carbon dioxide absorption unit is configured to bring the reaction gas into gas-liquid contact with an aqueous solution of hydroxide containing hydroxide, such that the aqueous hydroxide solution absorbs the carbon dioxide from the reaction gas and produces the inorganic substance.

To solve the above-mentioned technical problems, another technical solution adopted by the present invention is to provide a method for treating piranha solution and preparing calcium sulfate dihydrate, which includes: feeding a piranha solution or a piranha dilution solution and a calcium carbonate solution into a liquid mixing reaction unit and reacting them to produce a reaction liquid containing a reaction product; wherein the reaction product is calcium sulfate dihydrate; filtering and purifying the reaction liquid to precipitate the reaction product and separately forming a reflux liquid, which is then refluxed back to the piranha solution supply unit for dilution of the piranha solution, wherein the unfiltered calcium sulfate dihydrate crystals in the reflux liquid can be used as seed crystals and refluxed back to the liquid mixing reaction unit.

Preferably, before the reflux liquid is returned to the piranha liquid supply unit, the treatment method further includes: removing hydrogen peroxide from the reflux liquid by a hydrogen peroxide removal unit, or reducing the concentration of hydrogen peroxide in the reflux liquid.

The beneficial effect of this invention lies in the fact that the processing system and method for treating piranha solution and preparing calcium sulfate provided by this invention can, through "a liquid mixing reaction unit", "a piranha solution supply unit, configured to supply a piranha solution or a piranha dilute solution to the liquid mixing reaction unit", "a calcium carbonate solution mixing supply unit, configured to supply a calcium carbonate solution to the liquid mixing reaction unit, to mix and react with the piranha solution or the piranha dilute solution, thereby producing a reaction liquid containing a reaction product; wherein the reaction product is calcium sulfate dihydrate", and "a reaction liquid reflux unit, configured to reflux the reaction liquid". The technical solution involves filtering and purifying the piranha solution to precipitate the reaction product and form a separate reflux liquid, which is then returned to the piranha solution supply unit for dilution. This approach ensures proper treatment of the piranha solution, thereby addressing the environmental pollution problems caused by large-scale storage of waste piranha solution and mitigating the risks of explosions or liquid leaks. Furthermore, the piranha solution, processed by the system provided by this invention, can form a reaction product (calcium sulfate dihydrate, _CaSO₄ · _2H₂O ) with industrial application value, for example, it can be used as gypsum.

To further understand the features and technical content of this invention, please refer to the following detailed description and drawings of this invention. However, the drawings provided are for reference and illustration only and are not intended to limit this invention.

The following specific embodiments illustrate the disclosed embodiments of this invention. Those skilled in the art can understand the advantages and effects of this invention from the content disclosed in this specification. This invention can be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of this invention. The following embodiments will further explain the relevant technical content of this invention in detail, but the disclosed content is not intended to limit the scope of protection of this invention. It should be understood that although terms such as "first," "second," and "third" may be used in this document to describe various units or parameters, these units or parameters should not be limited by these terms.

[First Implementation Example]

Referring to Figure 1, the first embodiment of the present invention provides a processing system 100A for processing piranha solution and preparing calcium sulfate. The processing system 100A includes: a liquid mixing reaction unit 1, a piranha solution supply unit 2, a calcium carbonate solution mixing supply unit 3, a reaction liquid reflux unit 4, and a reaction product collection unit 5.

In this embodiment, the liquid mixing reaction unit 1 is a continuous stirred-tank reactor (CSTR).

The piranha liquid supply unit 2 is configured to supply a piranha solution S1 or a piranha dilute solution S1 to the liquid mixing reaction unit 1. The piranha solution S1 comprises sulfuric acid ( _H₂SO₄ ) and hydrogen peroxide ( _H₂O₂ ). The piranha dilute solution is a solution of the piranha solution diluted with water. In the piranha solution S1 or the piranha dilute solution S1, the weight ratio of sulfuric acid to hydrogen peroxide can be, for example, ₁₀ to ₃₀ :1. More specifically, the weight ratio of sulfuric acid to hydrogen peroxide can be, for example, 13 to 26:1. For example, the weight ratio of sulfuric acid to hydrogen peroxide is 15:1, but the invention is not limited to this.

From another perspective, each liter of the piranha solution S1 contains 110 to 210 _grams of sulfuric acid ( _H₂SO₄ ) and 7 to 11 _grams of hydrogen peroxide ( _H₂O₂ ), and the remaining liquid component of the piranha solution S1 is liquid water, but the invention is not limited thereto.

In this embodiment, the piranha solution S1 can be, for example, a liquid used in semiconductor manufacturing processes (such as substrate cleaning) or a waste liquid generated after the process is completed. Generally, the waste liquid of piranha solution is mainly diluted with a large amount of water and stored in a concentrated manner, which leads to the problem that it is difficult to deal with the large amount of waste liquid stored in time, and there may also be a risk of explosion or liquid leakage.

To solve this problem, the processing system provided by this embodiment can process waste piranha solution in real time and further prepare calcium sulfate dihydrate to recycle and utilize the piranha solution. To achieve the above objectives, the technical solution of this embodiment will be described below.

The calcium carbonate solution mixing and supply unit 3 mixes water and calcium carbonate powder to form a calcium carbonate solution S2, and supplies the calcium carbonate solution to the liquid mixing reaction unit 1 to mix with the piranha solution S1 or the piranha diluted solution S1.

More specifically, in the liquid mixing reaction unit 1, the piranha solution S1 or the piranha diluted solution S1 is mixed with the calcium carbonate solution S2 to form a mixed liquid.

The calcium carbonate ( _CaCO3 ) in the calcium carbonate solution S2 reacts with the sulfuric acid ( _H2SO4 ) in the piranha solution S1 or the diluted piranha solution _S1 to produce a reaction liquid S3 containing a reaction product S4. The reaction product S4 is calcium sulfate dihydrate ( _CaSO4 · _2H2O ).

In this embodiment, the calcium carbonate solution S2 is an aqueous solution of calcium carbonate, and each liter of the calcium carbonate solution S2 contains between 185 grams and 730 grams of calcium carbonate ( _CaCO3 ), but the invention is not limited thereto.

Furthermore, in order to improve the reaction efficiency of the piranha solution S1 (or diluted piranha solution S1) and the calcium carbonate solution S2, in some embodiments of the present invention, the first volumetric flow rate of the piranha solution S1 (or diluted piranha solution S1) introduced into the liquid mixing reaction unit 1 is 0.0007~0.0014 ^m³ /s, and the second volumetric flow rate of the calcium carbonate solution S2 introduced into the liquid mixing reaction unit 1 is 0.0004~0.0008 ^m³ /s. Moreover, the reaction temperature of the mixed liquid in the liquid mixing reaction unit 1 is between 25 and 55°C. Furthermore, the retention time of the piranha solution S1 (or piranha diluted solution S1) and calcium carbonate solution S2 in the liquid mixing reaction unit 1 is between 30 minutes and 90 minutes.

The reaction liquid reflux unit 4 is configured to filter and purify the reaction liquid S3 to precipitate the reaction product S4 (i.e., calcium sulfate dihydrate, _CaSO4 · _2H2O ), and the reaction liquid reflux unit 4 further transports the reaction product S4 to the reaction product collection unit 5. In this embodiment, the reaction liquid reflux unit 4 can be, for example, a filtration and purification device with a liquid reflux function. The reaction product S4 is in solid form (e.g., needle-like calcium sulfate dihydrate). Additionally, the reaction liquid reflux unit 4 further forms a reflux liquid S5 from the liquid other than the solid in the reaction liquid S3, and refluxes it back to the piranha liquid supply unit 2 for dilution of the piranha liquid. The reflux liquid S5 may, for example, contain unreacted hydrogen peroxide and the remaining sulfuric acid. It is worth mentioning that, in this embodiment, since the unreacted calcium carbonate is also removed after the reaction liquid S3 is filtered, thus terminating the reaction, and since the filtered solution is mostly water except for hydrogen peroxide and sulfuric acid, it can be refluxed to the piranha liquid supply unit 2 to dilute the piranha solution S1 (or piranha dilution solution S1). Furthermore, the unfiltered calcium sulfate dihydrate crystals present in the reflux liquid S5 (e.g., calcium sulfate dihydrate crystals with a particle size smaller than the filter screen) can serve as seed crystals and enter the liquid mixing reaction unit 1 along with the piranha dilution solution S1, thereby increasing the particle size of the dihydrate and calcium sulfate after the reaction and further improving the solid-liquid separation efficiency of the reaction liquid reflux unit 4.

The reaction product collection unit 5 is configured to collect the reaction product S4, and the reaction product collection unit 5 may be, for example, a collection tank or a beaker, but the invention is not limited thereto.

According to the above configuration, the piranha solution S1 can be properly treated by the treatment system 100A provided by this embodiment of the invention, thereby solving the problem of environmental pollution that may be caused by a large amount of stored piranha solution waste liquid, and also solving the problems of explosion risk or liquid leakage risk.

Furthermore, the piranha solution S1, processed by the treatment system 100A provided in this embodiment of the invention, can form a reaction product S4 (calcium sulfate dihydrate, _CaSO4 · _2H2O ) with industrial application value. For example, the reaction product S4 can be used as plaster for surgical fixation, dental molds and artificial bone fabrication, artistic creation, and interior decoration. Plaster is sometimes used as a desiccant in laboratories. Plaster is one of the raw materials for the industrial production of cement, or for the industrial production of chalk. Plaster can also be used as a soil conditioner in horticulture, but the invention is not limited thereto.

[Second Implementation Example]

Referring to Figure 2, a second embodiment of the present invention provides a treatment system 100B for processing piranha solution and preparing calcium sulfate dihydrate. The treatment system 100B includes: a liquid mixing reaction unit 1, a piranha solution supply unit 2, a calcium carbonate solution mixing supply unit 3, a reaction liquid reflux unit 4, a reaction product collection unit 5, and a hydrogen peroxide removal unit 6.

The treatment system 100B of the second embodiment of the present invention for treating piranha solution and preparing calcium sulfate dihydrate is substantially the same as the treatment system 100A provided in the first embodiment above. The difference is that the treatment system 100B of the second embodiment of the present invention further includes a hydrogen peroxide removal unit 6.

The hydrogen peroxide removal unit 6 is configured to receive the reflux liquid S5 returned by the reaction liquid reflux unit 4, and to remove hydrogen peroxide from the reflux liquid S5 or reduce the concentration of hydrogen peroxide in the reflux liquid S5.

Next, the hydrogen peroxide removal unit 6 further returns the treated reflux liquid S5 (with hydrogen peroxide removed or concentration reduced) to the piranha liquid supply unit 2, thereby diluting the piranha liquid.

In this way, the amount of water used to dilute the piranha liquid in the piranha liquid supply unit 2 can be effectively reduced.

In this embodiment, the hydrogen peroxide removal unit 6 may, for example, decompose the hydrogen peroxide in the reflux liquid S5 into water and oxygen by a hydrogen peroxide decomposing enzyme (e.g., catalase), so that the hydrogen peroxide in the reflux liquid S5 is removed or its concentration is reduced.

In another embodiment of the present invention, the hydrogen peroxide removal unit 6 may _, for example, hydrolyze the hydrogen peroxide in the reflux liquid S5 using a hydrogen peroxide removal agent (such as sodium sulfate sulfide, _{Na2S2O3 )} to remove or reduce the concentration of hydrogen peroxide in the reflux liquid S5.

[Third Implementation Example]

Please refer to Figure 3. The third embodiment of the present invention provides a treatment system 100C for treating piranha solution and preparing calcium sulfate. The treatment system 100C includes: a liquid mixing reaction unit 1, a piranha solution supply unit 2, a calcium carbonate solution mixing supply unit 3, a reaction liquid reflux unit 4, a reaction product collection unit 5, a hydrogen peroxide removal unit 6, a carbon dioxide purification unit 7a, and a carbon dioxide collection unit 8a.

The treatment system 100C of the third embodiment of the present invention for treating piranha solution and preparing calcium sulfate is substantially the same as the treatment system 100B provided in the second embodiment above. The difference is that the treatment system 100C of the third embodiment of the present invention further includes a carbon dioxide purification unit 7a and a carbon dioxide collection unit 8a.

After the piranha solution S1 and calcium carbonate solution S2 in the liquid mixing reaction unit 1 react, in addition to forming a reaction liquid S3 containing reaction product S4, a reaction gas S6 containing carbon dioxide (CO ₂ ) will also be formed.

In this embodiment, the carbon dioxide purification unit 7a is configured to receive the reaction gas S6 containing carbon dioxide ( _CO2 ) and purify the reaction gas S6 to form a purified gas S7a containing highly pure carbon dioxide. The carbon dioxide purification unit 7a can be, for example, a fixed-bed device employing pressure swing adsorption (PSA) or temperature swing adsorption (TSA), which can adsorb low concentrations of organic waste gas or other impurities in the reaction gas S6, thereby increasing the purity of the carbon dioxide in the gas.

In some embodiments of the present invention, the carbon dioxide purification unit 7a may also purify the reaction gas S6, for example, by solvent absorption or membrane separation.

Furthermore, the carbon dioxide collection unit 8a is configured to collect the purified gas S7a containing high-purity carbon dioxide. In this embodiment, the carbon dioxide collection unit 8a is a carbon dioxide collection bottle, but the invention is not limited thereto.

[Fourth Implementation Example]

Please refer to Figure 4. The fourth embodiment of the present invention provides a treatment system 100D for treating piranha solution and preparing calcium sulfate. The treatment system 100D includes: a liquid mixing reaction unit 1, a piranha solution supply unit 2, a calcium carbonate solution mixing supply unit 3, a reaction liquid reflux unit 4, a reaction product collection unit 5, a hydrogen peroxide removal unit 6, a carbon dioxide absorption unit 7b, and an inorganic substance collection unit 8b.

The treatment system 100D of the fourth embodiment of the present invention for treating piranha solution and preparing calcium sulfate is substantially the same as the treatment system 100B provided in the second embodiment above. The difference is that the treatment system 100D of the fourth embodiment of the present invention further includes a carbon dioxide absorption unit 7b and an inorganic matter collection unit 8b.

In addition to forming a reaction liquid S3 containing reaction product S4, the liquid mixing reaction unit 1 will also form a reaction gas S6 containing carbon dioxide ( _CO2 ).

The carbon dioxide absorption unit 7b is configured to receive the reaction gas S6 containing carbon dioxide ( _CO2 ) and absorb the reaction gas S6 to form an inorganic substance S7b.

More specifically, the carbon dioxide absorption unit 7b is configured to bring a reaction gas S6 containing carbon dioxide ( _CO2 ) into gas-liquid contact with an aqueous solution of hydroxide containing hydroxide, such that the aqueous hydroxide solution absorbs the carbon dioxide from the reaction gas S6 and produces the inorganic substance S7b. The inorganic substance S7b is a compound produced by the reaction of hydroxide and carbon dioxide.

In some embodiments of the present invention, the hydroxide is at least one of sodium hydroxide (NaOH) and potassium hydroxide (KOH). Additionally, the inorganic substance S7b can be, for example, an inorganic carbon source, and the inorganic carbon source is at least one of sodium bicarbonate ( _NaHCO3 ), sodium carbonate ( _Na2CO3 ), potassium bicarbonate ( _KHCO3 ), and _potassium carbonate ( _K2CO3 ). Furthermore, the carbon dioxide absorption unit 7b can be, for example _, a high-gravity rotating packed bed, but the present invention is not limited thereto.

Furthermore, the inorganic matter collection unit 8b is used to collect the inorganic matter S7b. The inorganic matter collection unit 8b can be, for example, a collection tank or a beaker, but the invention is not limited thereto. Thus, the inorganic matter S7b formed by the carbon dioxide absorption unit 7b can be used, for example, for algae cultivation, thereby enhancing the commercial application value of the reaction products.

[Fifth Implementation Example]

Please refer to Figure 5. The fifth embodiment of the present invention provides a treatment system 100E for treating piranha solution and preparing calcium sulfate. The treatment system 100E includes: a liquid mixing reaction unit 1, a piranha solution supply unit 2, a calcium carbonate solution mixing supply unit 3, a reaction liquid reflux unit 4, a reaction product collection unit 5, a hydrogen peroxide removal unit 6, a carbon dioxide purification unit 7a and a carbon dioxide collection unit 8a arranged together, and a carbon dioxide absorption unit 7b and an inorganic substance collection unit 8b arranged together.

The main difference between the processing system 100E of the fifth embodiment of the present invention and the above embodiments is that the processing system 100E simultaneously includes a carbon dioxide purification unit 7a, a carbon dioxide collection unit 8a, a carbon dioxide absorption unit 7b, and an inorganic matter collection unit 8b.

In this way, the reaction gas S6 containing carbon dioxide ( _CO2 ) can enter the carbon dioxide purification unit 7a and the carbon dioxide absorption unit 7b by splitting the flow to form a purified gas S7a (containing highly purified carbon dioxide) and an inorganic substance S7b (e.g., sodium bicarbonate _NaHCO3 , _sodium carbonate _Na2CO3 , potassium bicarbonate _KHCO3 , or potassium carbonate _{K2CO3 )} .

[Treatment method for treating piranha solutions and preparing calcium sulfate]

Another embodiment of the present invention also provides a method for treating a piranha solution and preparing calcium sulfate, which includes steps S110 to S130. It should be noted that the order of the steps and the actual operation method described in this embodiment can be adjusted as needed and are not limited to those described in this embodiment.

Step S110 includes: feeding a piranha solution S1 or a piranha dilute solution S1 and a calcium carbonate solution S2 into a liquid mixing reaction unit 1 and reacting them to produce a reaction liquid S3 containing a reaction product S4. The reaction product S4 is calcium sulfate dihydrate ( _CaSO4 · _2H2O ).

Step S120 includes: filtering and purifying the reaction liquid S3 to precipitate the reaction product S4 (i.e., calcium sulfate dihydrate, _CaSO4 · _2H2O ), and forming a reflux liquid S5 from the unfiltered and unpurified liquid (excluding solids) in the reaction liquid S3, and refluxing it back to the piranha liquid supply unit 2 to dilute the piranha liquid.

The reflux liquid S5 contains incompletely filtered calcium sulfate dihydrate crystals, which can be used as seed crystals and are refluxed into the liquid mixing reaction unit 1 along with the piranha dilution solution S1.

The piranha solution S1 can be processed by the method provided in this embodiment of the invention to form a reaction product S4 (calcium sulfate dihydrate, _CaSO4 · _2H2O ) with industrial application value.

In one embodiment, before the reflux liquid S5 is refluxed to the piranha liquid supply unit 2, step S120 further includes: removing hydrogen peroxide from the reflux liquid S5 by a hydrogen peroxide removal unit 6, or reducing the concentration of hydrogen peroxide in the reflux liquid S5.

Step S130 includes: purifying a reaction gas S6 containing carbon dioxide ( _CO2 ) produced in the liquid mixing reaction unit 1 to form a purified gas S7a; or absorbing the reaction gas S6 to form an inorganic substance S7b.

_The purified gas S7 contains highly purified carbon dioxide. The inorganic substance S7b can be an inorganic carbon source, and the inorganic carbon source is at least one of sodium bicarbonate ( _NaHCO3 ), sodium carbonate ( _Na2CO3 ), potassium bicarbonate ( _KHCO3 ), and _potassium carbonate ( _K2CO3 ).

[Beneficial effects of the implementation]

The beneficial effect of this invention lies in the fact that the treatment system and method for treating piranha solution and preparing calcium sulfate provided by this invention can, through "a liquid mixing reaction unit", "a piranha solution supply unit configured to supply a piranha solution or a piranha dilute solution to the liquid mixing reaction unit", "a calcium carbonate solution mixing supply unit configured to supply a calcium carbonate solution to the liquid mixing reaction unit, so as to mix and react with the piranha solution, thereby producing a reaction liquid containing a reaction product; wherein the reaction product is calcium sulfate dihydrate", and "a reaction liquid reflux unit configured to reflux the reaction liquid". The technical solution involves filtration and purification to precipitate the reaction product from the reaction liquid, forming a separate reflux liquid that is returned to the piranha liquid supply unit for dilution. This allows the piranha solution to be properly treated, thereby solving the environmental pollution problem that may be caused by large-scale storage of waste piranha solution, and also addressing the risks of explosion or liquid leakage. Furthermore, the piranha solution, through the treatment system provided by this invention, can form a reaction product (calcium sulfate dihydrate, _CaSO₄ · _2H₂O ) with industrial application value. For example, the reaction product can be used as gypsum.

The above-disclosed content is merely a preferred feasible embodiment of the present invention and is not intended to limit the scope of the patent application of the present invention. Therefore, all equivalent technical changes made using the contents of the present invention's description and drawings are included within the scope of the patent application of the present invention.

100A, 100B, 100C, 100D, 100E: Processing System 1: Liquid Mixing Reaction Unit 2: Piranha Solution Supply Unit 3: Calcium Carbonate Solution Mixing Supply Unit 4: Reaction Liquid Reflux Unit 5: Reaction Product Collection Unit 6: Hydrogen Peroxide Removal Unit 7a: Carbon Dioxide Purification Unit 7b: Carbon Dioxide Absorption Unit 8a: Carbon Dioxide Collection Unit 8b: Inorganic Substance Collection Unit S1: Piranha Solution, Piranha Diluted Solution S2: Calcium Carbonate Solution S3: Reaction Liquid S4: Reaction Product S5: Reflux Liquid S6: Reaction Gas S7a: Purified Gas S7b: Inorganic Substance

Figure 1 is a system block diagram of the processing system of the first embodiment of the present invention.

Figure 2 is a system block diagram of the processing system of the second embodiment of the present invention.

Figure 3 is a system block diagram of the processing system of the third embodiment of the present invention.

Figure 4 is a system block diagram of the processing system of the fourth embodiment of the present invention.

Figure 5 is a system block diagram of the processing system of the fifth embodiment of the present invention.

100E: Processing System

1: Liquid Mixture Reaction Unit

2: Piranha Liquid Supply Unit

3: Calcium carbonate solution mixing and supply unit

4: Reaction Liquid Reflux Unit

5: Reaction Product Collection Unit

6: Hydrogen peroxide removal unit

7a: Carbon dioxide purification unit

7b: Carbon Dioxide Absorption Unit

8a: Carbon Dioxide Collection Unit

8b: Inorganic material collection unit

S1: Piranha solution, diluted piranha solution Piranha solution

S2: Calcium carbonate solution

S3: Reaction liquid

S4: Reaction product

S5: Returning liquid

S6: Reacting gas

S7a: Purified gas

S7b: Inorganic substances

Claims (10)

A processing system for treating piranha solution and preparing calcium sulfate includes: a liquid mixing reaction unit; and a piranha solution supply unit configured to supply a piranha solution or a piranha dilute solution to the liquid mixing reaction unit, wherein the piranha solution contains sulfuric acid ( _H₂SO₄ ) and hydrogen peroxide ( _H₂O₂ ) _, and wherein the weight ratio of sulfuric acid to hydrogen peroxide in the piranha solution or the piranha dilute solution is between 10 and ₃₀ :1. A calcium carbonate solution mixing and supply unit is configured to supply a calcium carbonate solution to the liquid mixing reaction unit for mixing and reaction with the piranha solution or the diluted piranha solution to produce a reaction liquid containing a reaction product, wherein the reaction product is calcium sulfate dihydrate; and a reaction liquid reflux unit is configured to filter and purify the reaction liquid to remove the calcium carbonate solution from the liquid. The reaction product is precipitated from the reaction liquid, and the reaction liquid reflux unit separately forms a reflux liquid, which is refluxed back to the piranha liquid supply unit to dilute the piranha liquid. The reflux liquid contains incompletely filtered calcium sulfate dihydrate crystals, which can be used as seed crystals and are refluxed back to the liquid mixing reaction unit to increase the particle size of the reacted calcium sulfate dihydrate. The processing system for processing piranha solution and preparing calcium sulfate as described in claim 1, wherein the piranha solution provided by the piranha solution supply unit is a liquid used in a semiconductor manufacturing process or a waste liquid generated after the process is completed; the piranha diluent is a solution of the piranha solution diluted with water. A treatment system for processing piranha solutions and preparing calcium sulfate as described in claim 1, wherein, in the liquid mixing reaction unit, the calcium carbonate ( _CaCO3 ) contained in the calcium carbonate solution reacts with _the sulfuric acid ( _H2SO4 ) contained in the piranha solution to produce the reaction liquid containing the reaction products. The treatment system for processing piranha solution and preparing calcium sulfate as described in claim 1, wherein the piranha solution is introduced into the liquid mixing reaction unit at a first volumetric flow rate of 0.0007~0.0014 ^m³ /s, and the calcium carbonate solution is introduced into the liquid mixing reaction unit at a second volumetric flow rate of 0.0004~0.0008 ^m³ /s. The treatment system for processing piranha solution and preparing calcium sulfate as described in claim 1 further comprises: a hydrogen peroxide removal unit configured to receive the reflux liquid returned from the reaction liquid reflux unit, and to remove hydrogen peroxide from the reflux liquid or reduce the concentration of hydrogen peroxide in the reflux liquid; and then, to return the reflux liquid to the piranha solution supply unit. The processing system for treating piranha solution and preparing calcium sulfate as described in claim 1, wherein after the piranha solution and the calcium carbonate solution in the liquid mixing reaction unit react, a reaction gas containing carbon dioxide is further formed; wherein the processing system further includes: a carbon dioxide purification unit configured to receive the reaction gas and purify the reaction gas to form a purified gas containing highly pure carbon dioxide. The processing system for treating piranha solution and preparing calcium sulfate as described in claim 1, wherein after the piranha solution and the calcium carbonate solution in the liquid mixing reaction unit react, a reaction gas containing carbon dioxide is further formed; wherein the processing system further includes: a carbon dioxide absorption unit configured to receive the reaction gas and absorb the reaction gas to form an inorganic substance. The treatment system for treating piranha solution and preparing calcium sulfate as described in claim 7, wherein the carbon dioxide absorption unit is configured to bring the reaction gas into gas-liquid contact with an aqueous solution of hydroxide containing hydroxide, such that the aqueous solution of hydroxide absorbs the carbon dioxide in the reaction gas and produces the inorganic substance. A method for processing piranha solution and preparing calcium sulfate includes: separately feeding a piranha solution or a diluted piranha solution and a calcium carbonate solution provided by a piranha solution supply unit into a liquid mixing reaction unit and reacting them to produce a reaction liquid containing a reaction product; wherein the piranha solution contains sulfuric acid ( _H₂SO₄ ) and hydrogen peroxide ( _{H₂O₂ ) .} The reaction involves filtration and purification of the reaction liquid to precipitate the reaction product and form a reflux liquid, which is then returned to the piranha solution supply unit for dilution of the piranha solution. The reflux liquid contains incompletely filtered calcium sulfate dihydrate crystals, which can serve as seed crystals and are returned to the liquid mixing reaction unit to increase the particle size of the reacted calcium sulfate dihydrate. The method for treating piranha solution and preparing calcium sulfate as described in claim 9, wherein, before the reflux liquid is refluxed to the piranha solution supply unit, the method further comprises: removing hydrogen peroxide from the reflux liquid by a hydrogen peroxide removal unit, or reducing the concentration of hydrogen peroxide in the reflux liquid.