KR100582524B1 - A method of recycling used etchant containing phosphoric acid - Google Patents
A method of recycling used etchant containing phosphoric acid Download PDFInfo
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- KR100582524B1 KR100582524B1 KR1020040048175A KR20040048175A KR100582524B1 KR 100582524 B1 KR100582524 B1 KR 100582524B1 KR 1020040048175 A KR1020040048175 A KR 1020040048175A KR 20040048175 A KR20040048175 A KR 20040048175A KR 100582524 B1 KR100582524 B1 KR 100582524B1
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
- C23F1/00—Etching metallic material by chemical means
- C23F1/46—Regeneration of etching compositions
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- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
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- B01D15/00—Separating processes involving the treatment of liquids with solid sorbents; Apparatus therefor
- B01D15/08—Selective adsorption, e.g. chromatography
- B01D15/26—Selective adsorption, e.g. chromatography characterised by the separation mechanism
- B01D15/36—Selective adsorption, e.g. chromatography characterised by the separation mechanism involving ionic interaction
- B01D15/361—Ion-exchange
- B01D15/362—Cation-exchange
Abstract
본 발명은 반도체와 TFT-LCD 등의 제조 공정에서 발생하는 인산 함유 폐식각액의 재생방법에 관한 것으로서, 인산 함유 폐식각액을 감압증류하여 얻어진 증류여액(고농도 인산)을 증류수로 희석시킨 희석액(인산 수용액)을 마이크로 필터링과 나노 필터링하기 전에 상기 희석액에 착화제를 투입하는 공정을 포함하는 것을 특징으로 한다.The present invention relates to a method for regenerating a phosphoric acid-containing waste etchant generated in a manufacturing process such as semiconductors and TFT-LCDs, and a dilution (dilute phosphoric acid solution) in which distilled filtrate (high concentration phosphoric acid) obtained by distilling the phosphoric acid-containing waste etchant under reduced pressure is distilled. ) Is added to the diluent before the micro-filtering and nano-filtering.
본 발명은 인산 함유 폐식각액 내에 녹아있는 금속이온을 99.9%이상 제거하여 고순도의 인산을 회수할 수 있고, 회수된 고순도의 인산을 사용하여 인산 함유 식각액을 재조성함으로서 인산 함유 폐식각액을 연속적으로 재생할 수 있다.The present invention can recover high purity phosphoric acid by removing more than 99.9% of the metal ions dissolved in the phosphoric acid-containing waste etching solution, and continuously regenerate the phosphoric acid-containing waste etching solution by reconstituting the phosphoric acid-containing etching solution using the recovered high purity phosphoric acid. Can be.
착화제, 나노 필터링, 마이크로 필터링, 폐식각액, 고순도 인산, 재생, 이온교환수지, 전기화학적 활성화.Complexing agent, nano filtering, micro filtering, waste etchant, high purity phosphoric acid, regeneration, ion exchange resin, electrochemical activation.
Description
도 1 내지 도 4는 본 발명의 공정 개략도.1-4 are process schematic diagrams of the present invention.
본 발명은 반도체와 TFT-LCD(Thin Film Transistor-Liquid Crystal Display)등의 제조공정에서 발생하는 인산 함유 폐식각액의 재생방법에 관한 것이다.BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for regenerating a phosphoric acid-containing waste etchant generated in a manufacturing process such as semiconductor and TFT-LCD (Thin Film Transistor-Liquid Crystal Display).
TFT-LCD 등의 제조시 알루미늄등을 식각하기 위하여 주성분인 인산(Phosphoric Acid, H3PO4)과 그 외의 질산 및 초산을 함유하는 혼합산(이하 "인산 함유 혼합산"이라고 한다)을 사용하며, 식각공정에 사용된 상기 인산 함유 혼합산에는 알루미늄과 몰리브데늄을 포함하는 금속성분이 미량 녹아 있게 된다.Phosphoric Acid (H 3 PO 4 ) and mixed acid containing other nitric and acetic acid (hereinafter referred to as "phosphoric acid-containing mixed acid") are used to etch aluminum during TFT-LCD manufacturing. In the phosphoric acid-containing mixed acid used in the etching process, a trace amount of a metal component including aluminum and molybdenum is dissolved.
이하, 본 발명에서는 TFT-LCD등의 제조시 알루미늄등을 식각하기 위하여 사용되는 상기의 인산 함유 혼합산을 "인산 함유 식각액"이라고 약칭하고, TFT-LCD등 의 제조시 알루미늄과 몰리브데늄등의 금속막을 식각하는데 사용되어 알루미늄과 몰리브데늄 등을 포함하는 금속성분이 미량 녹아 있는 인산 함유 혼합액을 "인산 함유 폐식각액"이라고 약칭한다.Hereinafter, in the present invention, the above-mentioned phosphoric acid-containing mixed acid used for etching aluminum and the like in TFT-LCD and the like is abbreviated as "phosphate-containing etchant", and in the case of TFT-LCD and the like, aluminum and molybdenum and the like Phosphoric acid-containing mixed solution, which is used to etch a metal film and has a small amount of a metal component containing aluminum, molybdenum, and the like, is abbreviated as "phosphate-containing waste etching liquid".
보다 구체적으로, 본 발명은 인산함유 폐식각액 내에 녹아 있는 금속이온을 99.9%이상 제거하여 고순도의 인산을 회수하고, 이를 사용하여 인산 함유 식각액을 재조성 함으로서 인산 함유 폐식각액을 재생하는 방법에 관한 것이다.More specifically, the present invention relates to a method for regenerating a phosphoric acid-containing waste etching solution by removing 99.9% or more of metal ions dissolved in the phosphoric acid-containing waste etching solution to recover high-purity phosphoric acid, and reconstituting the phosphoric acid-containing etching solution. .
반도체 및 TFT-LCD등의 제조공정에서 인산 함유 식각액이 사용되는 공정들을 보다 구체적으로 살펴보면, 인산 함유 식각액은 (ⅰ) 실리콘 단결정 웨이퍼 제조공정 중 절삭 및 조연마 공정에서 발생한 기계적 결함을 제거하는 공정, (ⅱ) 반도체 소자 제조시 절연막으로 실리콘 질화막을 증착 시킨 후 이를 선택적으로 식각하는 공정 및 (ⅲ) TFT-LCD 제조시 알루미늄/몰리브데늄 재질의 전극을 선택적으로 식각하는 공정 등에 사용된다.In more detail, processes in which phosphoric acid-containing etching liquids are used in manufacturing processes such as semiconductors and TFT-LCDs may be described. The phosphoric acid-containing etching liquid may be a process for removing mechanical defects generated during the cutting and polishing process during the silicon single crystal wafer manufacturing process. (Ii) a process of selectively depositing a silicon nitride film as an insulating film in the manufacture of semiconductor devices, and (i) selectively etching an electrode made of aluminum / molybdenum during TFT-LCD manufacturing.
상기 공정들에서 사용된 인산 함유 폐식각액으로부터 고순도의 인산을 회수하여 이를 다시 인산 함유 식각액 재조성에 사용하는 방법, 다시 말해 인산 함유 식각액의 재생방법,은 현재까지 개발되지 않았다.A method of recovering high-purity phosphoric acid from the phosphoric acid-containing waste liquor used in the above processes and using the same for reconstituting the phosphoric acid-containing etchant, that is, a method of regenerating the phosphoric acid-containing etchant, has not been developed until now.
그로 인해, 현재까지는 인산 함유 폐식각액을 통상의 중화 침전법 등으로 간단히 처리한 후 비료 제조 공정에 이용하고 있으나, 고순도의 인산은 고가이기 때문에 인산 함유 폐식각액으로부터 고순도의 인산을 회수하여 재사용하는 경우와 비교시 경제적으로 바람직하지 않다.Therefore, until now, the phosphoric acid-containing waste etching solution has been simply processed by a conventional neutralization precipitation method and then used in the fertilizer manufacturing process. However, since the high purity phosphoric acid is expensive, the high purity phosphoric acid is recovered from the phosphoric acid-containing waste etching solution and reused. It is economically undesirable compared with.
인산을 정제하는 종래 기술로서 증류방법이 널리 사용되고 있으나, 이 경우 사불화 실리콘 등의 불화물은 제거되나 알루미늄, 마그네슘 등의 금속이 제거되지 않아 인산 함유 폐식각액의 재생에는 사용될 수 없는 한계가 있었다.As a conventional technique for purifying phosphoric acid, a distillation method is widely used, but in this case, fluorides such as silicon tetrafluoride are removed, but metals such as aluminum and magnesium are not removed, and thus, there is a limitation that the distillation method cannot be used for regeneration of the waste etching solution containing phosphoric acid.
또한, 인산을 정제하는 종래 기술로서 용매 추출방법과 기공의 평균 입경이 나노 또는 마이크로 수준인 다공성 필터를 이용하여 필터링 하는 방법이 논문 및 미국특허 제 4,277,448호 등에 의해 알려져 있으나, 상기 방법들로는 인산 함유 폐식각액 내에 함유된 알루미늄 등의 금속이온을 효과적으로 제거할 수 없어서 인산 함유 폐식각액의 재생에는 사용될 수 없었다.In addition, as a conventional technique for purifying phosphoric acid, a solvent extraction method and a method of filtering using a porous filter having an average particle diameter of pores of nano or micro level are known from the paper and US Patent No. 4,277,448. Metal ions such as aluminum contained in the etchant could not be effectively removed and thus could not be used for regeneration of the phosphoric acid-containing waste etchant.
본 발명의 목적은 상기와 같은 종래 기술의 문제점들을 해결하여 인산 함유 폐식각액으로부터 고순도의 인산을 회수, 재사용하므로서 인산 함유 폐식각액을 효율적으로 재생하는 방법을 제공하기 위한 것이다.SUMMARY OF THE INVENTION An object of the present invention is to provide a method of efficiently regenerating a phosphoric acid-containing waste etchant by recovering and reusing high purity phosphoric acid from a phosphoric acid-containing waste etchant by solving the problems of the prior art as described above.
본 발명은 반도체 및 TFT-LCD 등의 제조공정에서 발생하는 인산 함유 폐식각액으로부터 고순도의 인산을 회수한 후 이를 사용하여 인산 함유 식각액을 재조성 함으로서 인산 함유 폐식각액을 재생하는 방법을 제공하고자 한다.The present invention is to provide a method for regenerating the phosphoric acid-containing waste etching solution by recovering the high-purity phosphoric acid from the phosphoric acid-containing waste etching solution generated in the manufacturing process, such as semiconductor and TFT-LCD, and then reconstituting the phosphoric acid-containing etching solution.
이를 위해, 본 발명에서는 인산 함유 폐식각액 내 금속이온이 마이크로 필터 및 나노 필터에 효과적으로 필터링 될 수 있도록 인산 함유 폐식각액을 전처리(감압증류, 희석 및 착화제 처리)하는 방법을 제공하고자 한다.To this end, the present invention is to provide a method for pretreatment (pressure distillation, dilution and complexing agent treatment) of the phosphoric acid-containing waste etching solution to effectively filter the metal ions in the phosphoric acid-containing waste etching solution to the micro-filter and nano-filter.
보다 구체적으로, 본 발명에서는 인산 함유 폐식각액을 감압증류하여 얻어진 증류여액(고농도 인산)을 증류수로 희석시킨 희석액(인산수용액)을 마이크로 필터 링 및 나노 필터링 하기 이전에 상기 희석액에 착화제를 가하여 인산 함유 폐식각액 내에 존재하는 다양한 화학종 형태의 금속불순물들을 나노 필터링 방식으로 분리 정제하기에 적절한 이온종 형태의 금속불순물로 변환시켜 주는 방법을 제공하고자 한다.
More specifically, in the present invention, a diluent (phosphate aqueous solution) obtained by distilling the distilled filtrate (high concentration phosphoric acid) obtained by distillation under reduced pressure of a phosphoric acid-containing waste etching solution with distilled water is added to the diluent by adding a complexing agent to the dilute solution before microfiltering and nanofiltering. The present invention provides a method for converting metal impurities of various chemical species present in the containing waste etchant into ionic species of metal impurities suitable for separation and purification by nano-filtering method.
이와 같은 과제들을 달성하기 위한 본 발명의 인산 함유 폐식각액의 재생방법은, 인산 함유 폐식각액을 감압증류하여 얻어진 증류여액(고농도 인산)을 증류수로 희석시킨 희석액(인산 수용액)을 마이크로 필터링과 나노 필터링 하기 전에 상기 희석액에 착화제를 투입하는 공정을 포함하는 것을 특징으로 한다.In order to achieve the above problems, the method for regenerating the phosphate-containing waste etching solution of the present invention may include microfiltration and nano-filtering of a dilution (aqueous phosphoric acid solution) obtained by distilling the distillation filtrate (high concentration phosphoric acid) obtained by distillation under reduced pressure with phosphoric acid-containing waste etching solution. Before it is characterized in that it comprises a step of adding a complexing agent to the diluent.
또한, 본 발명은 아래의 공정들을 포함하는 것을 특징으로 한다.In addition, the present invention is characterized by including the following steps.
- 아 래 - -Below-
(ⅰ) 인산 함유 폐식각액을 감압증류하는 공정;(Iii) distilling under reduced pressure the phosphoric acid-containing waste etchant;
(ⅱ) 상기 감압증류 공정으로 얻어지는 증류여액(고농도 인산)을 증류수로 희석하는 공정;(Ii) diluting the distillation filtrate (high concentration phosphoric acid) obtained by the distillation under reduced pressure with distilled water;
(ⅲ) 희석공정에서 얻어진 희석액(인산 수용액)에 착화제를 투입하는 공정;(Iii) adding a complexing agent to a dilution liquid (aqueous phosphoric acid solution) obtained in the dilution step;
(ⅳ) 착화제가 투입된 희석액을 마이크로 필터링 하는 공정;(Iii) microfiltering the diluent to which the complexing agent is added;
(ⅴ) 마이크로 필터링 된 희석액(인산 수용액)을 나노 필터링 하는 공정;(Iii) nano-filtering the microfiltered diluent (phosphate aqueous solution);
(ⅵ) 나노 필터링된 희석액(인산 수용액)을 감압증류하여 고순도의 인산을 회수하는 공정;(Iii) recovering high purity phosphoric acid by distilling under reduced pressure a nano-filtered diluent (aqueous phosphoric acid solution);
(ⅶ) 회수된 고순도의 인산을 사용하여 인산 함유 식각액을 재조성하는 공정.(Iii) A process for reconstituting an etching solution containing phosphoric acid using the recovered high purity phosphoric acid.
이하, 첨부한 도면 등을 통하여 본 발명을 상세하게 설명한다.Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
도 1 내지 도 4는 본 발명의 공정개략도이다.1 to 4 are process schematic diagrams of the present invention.
먼저, 본 발명은 도 1 내지 도 4와 같이 인산 함유 폐식각액 내에 포함된 질산 등과 같이 강한 산화성을 가진 화합물을 제거하기 위해서 인산 함유 폐식각액을 감압증류 한다.First, the present invention is distilled under reduced pressure to phosphate-containing waste etching solution in order to remove a compound having strong oxidizing properties, such as nitric acid contained in the phosphoric acid-containing waste etching solution as shown in FIGS.
상기의 강한 산화성을 가진 화합물은 이후 마이크로 필터링 및 나노 필터링 공정에서 필터 막의 분해를 야기 시켜 필터 막의 수명을 크게 감소시키므로 상기 감압 증류 공정으로 인산 함유 폐식각액 내 질산 등의 산화성 화합물을 제거한다.Since the compound having strong oxidizing property causes degradation of the filter membrane in the micro-filtering and nano-filtering process, thereby greatly reducing the life of the filter membrane, the oxidizing compound such as nitric acid in the phosphoric acid-containing waste etching solution is removed by the vacuum distillation process.
고점성 인산은 가온시 쉽게 고분자화 되기 때문에 상온 내지 150℃로 비교적 낮은 온도영역에서 박막 감압증류법을 채택하는 것이 보다 바람직하다. Since high-viscosity phosphoric acid easily polymerizes when heated, it is more preferable to adopt a thin film vacuum distillation method at a relatively low temperature range from room temperature to 150 ° C.
상기 감압증류 공정을 통해 인산 함유 폐식각액 내 인산 함량을 90중량% 이상으로 높여 준다.Through the vacuum distillation process to increase the phosphoric acid content in the phosphoric acid-containing waste etching solution to more than 90% by weight.
상기 감압증류 공정에서 분리되는 증류액은 도 1 내지 도 4와 같이 인산 함유 폐식각액으로 부터 회수된 고순도 인산으로 인산 함유 식각액을 재조성하는 공정으로 공급되어 재사용 하는 것이 보다 바람직하다.The distillate separated in the distillation under reduced pressure is more preferably supplied and reused in the process of reconstituting the phosphate-containing etching solution with high-purity phosphoric acid recovered from the phosphate-containing waste etching solution as shown in FIGS.
다음으로는, 도 1 내지 도 4와 같이 상기 감압증류 공정에서 얻어진 증류여액(고농도 인산)을 증류수로 희석하여 희석액(인산 수용액)을 제조하는 희석 공정을 거친다.Next, as shown in FIGS. 1 to 4, the distillation filtrate (high concentration phosphoric acid) obtained in the vacuum distillation process is diluted with distilled water, followed by a dilution process for preparing a dilution solution (phosphate aqueous solution).
상기 희석 공정은 이후 나노 필터링 공정의 효율을 높이기 위해 적절한 농도로 실시한다.The dilution process is then carried out at an appropriate concentration to increase the efficiency of the nano-filtering process.
상기 희석 공정시 희석액 내 인산의 농도가 40% 이하가 되도록 조절하는 것이 바람직하며, 희석공정에서는 금속 불순물의 함량이 각각의 원소에 대해 10ppt(part per trilion) 이하의 탈이온수인 증류수를 사용하는 것이 바람직하다.In the dilution process, it is preferable to adjust the concentration of phosphoric acid in the diluent to be 40% or less, and in the dilution process, it is preferable to use distilled water having deionized water of 10 ppt (part per trilion) or less for each element. desirable.
다음으로는, 도 1 내지 도 4와 같이 희석공정에서 얻어진 희석액(인산 수용액)에 착화제를 투입하여 상기 희석액내 금속불순물 화학종을 변화시키는 공정을 거친다.Next, a complexing agent is added to the dilution liquid (phosphate aqueous solution) obtained in the dilution process as shown in FIGS. 1 to 4 to change the metal impurity species in the dilution liquid.
상기 공정은 희석액(인산 수용액)내에 다양한 화학종 형태로 존재하는 금속불순물들을 필터링으로 정제하기 쉬운 이온종으로 변환시키는 목적으로 실시된다. 보다 구체적으로, 희석 처리된 인산 함유 폐식각액 내에는 금속성분들이 입자상, 착화합물, 양이온 및 음이온 등과 같은 다양한 화학종 형태로 존재한다. 특히 몰리브데늄(Mo)은 나노 필터링으로 정제하기 어렵다. 따라서 본 발명은 상기와 같이 착화제를 가하여 다양한 화학종 형태로 존재하는 금속 불순물들을 마이크로 필터링과 나노 필터링으로 정제하기 용이한 이온종으로 변환시켜 주기 위한 것이다.The process is carried out for the purpose of converting metal impurities present in various chemical species forms in diluents (aqueous phosphoric acid solution) into ionic species which are easy to purify by filtering. More specifically, metal components are present in various chemical species such as particulates, complexes, cations and anions in the dilute phosphoric acid-containing waste etching solution. In particular, molybdenum (Mo) is difficult to purify by nano-filtering. Therefore, the present invention is to add a complexing agent as described above to convert the metal impurities present in the form of various species into ionic species that are easy to purify by micro-filtering and nano-filtering.
상기와 같이 희석액(인산 수용액)내의 금속불순물들의 화학종을 필터링하기 쉽게 변화시키기 위해 첨가되는 착화제로는 트리부틸 포스페이트(Tributyl Phosphate), 에틸렌디아민 테트라아세틱 산(Etylenediamine tetraacetic acid), 니트리로트리아세틱 산(Nitrilotriacetic acid), 아리자린(7,8-디히드록시-5,6-프탈퀴아노린[Alizarine(7,8-dihydroxy-5,6-phtalquinoline)] 아라민(Alamin)336(트리- C8-C6 아민), 1,10-페난트로린(1,10-Phenanthroline), α,α'-디피리딘(α,α'-dipyridine)등이 사용된다.As a complexing agent added to easily change the species of the metal impurities in the diluent (aqueous phosphate solution) as described above, tributyl phosphate, ethylenediamine tetraacetic acid, nitrilotriacetic Nitrilotriacetic acid, Alizarin (7,8-dihydroxy-5,6-phtalquinoline) Alamin 336 (tri-C 8- C 6 amine), 1,10-Phenanthroline, α, α'-dipyridine and the like.
본 발명에서는 상기와 같이 착화제가 투입된 희석액(인산 수용액)을 마이크로 필터링과 나노 필터링 하기전에 착화합물의 형성을 유도하기 위해서 선택적으로상기 희석액(인산 수용액)에 전기 에너지를 가하여 상기 희석액(인산 수용액)을 전기화학적으로 활성화 시킬 수도 있다.In the present invention, in order to induce the formation of a complex compound before micro-filtering and nano-filtering the diluent (phosphate aqueous solution) to which the complexing agent is added as described above, electric energy is selectively added to the diluent (phosphate aqueous solution) to supply the diluent (phosphate aqueous solution). It can also be activated chemically.
상기와 같이 희석액(인산 수용액)을 전기화학적으로 활성화시키기 위해서는 특수 재질의 전극을 사용하여 상기 희석액(인산 수용액)에 전압이 0.1 ~ 10V이며 주파수가 50 ~ 1,000,000㎐인 교류를 가해 주는 방법이 바람직하다.In order to activate the diluent (phosphate solution) electrochemically as described above, it is preferable to apply an alternating current having a voltage of 0.1 to 10 V and a frequency of 50 to 1,000,000 Hz to the diluent solution (phosphate solution) using an electrode of a special material. .
상기 희석액에 교류 대신에 직류를 가하면 전극 표면에 금속이온이 석출되어 전극의 효율이 감소될 수 있다.When a direct current is applied to the diluent instead of an alternating current, metal ions may be deposited on the electrode surface, thereby reducing the efficiency of the electrode.
다음으로는, 도 1 내지 도 4와 같이 착화제가 투입된 희석액(인산 수용액) 또는 착화제가 투입되고 전기활성화된 희석액(인산 수용액)을 마이크로 필터링한 다음, 계속해서 나노 필터링 한다.Next, as shown in FIGS. 1 to 4, the dilution solution (phosphate aqueous solution) or the complexing agent added and electroactivated dilution solution (phosphate aqueous solution) is micro-filtered, followed by nano-filtering.
이때, 금속불순물 화학종을 효과적으로 제거하기 위하여 희석액의 인산 함유 농도, 필터링 압력, 희석액(인산 수용액)의 흐름 등을 적절히 조절하는 것이 좋다.In this case, in order to effectively remove the metal impurity species, it is preferable to appropriately adjust the concentration of the phosphoric acid containing the diluent, the filtering pressure, and the flow of the diluent (aqueous phosphoric acid solution).
마이크로 필터링은 기공(pore) 크기가 0.1~1.0㎛인 고분자 다공성 막을 사용하여 실시하고, 나노 필터링은 기공(pore) 크기가 0.0001~0.001㎛인 고분자 다공성막을 사용하여 실시한다.Micro-filtering is carried out using a porous polymer membrane having a pore size of 0.1 ~ 1.0㎛, nano-filtering is carried out using a polymeric porous membrane having a pore size of 0.0001 ~ 0.001㎛.
상기 고분자 다공성 막의 재질로는 폴리이미드(Polyimide), 폴리아미드(Polyamide), 테프론(Teflon)등과 같은 각종 고분자가 사용될 수 있다.As a material of the polymer porous membrane, various polymers such as polyimide, polyamide, Teflon, and the like may be used.
또한, 상기 마이크로 필터링은 30 psig(pund per squard inch) 이하의 압력하에 상온 내지 80℃에서 실시하고, 나노 필터링은 50~300 psig(pund per squard inch)의 압력하에서 상온 내지 80℃에서 실시하는 것이 바람직하다.In addition, the micro-filtering is carried out at room temperature to 80 ℃ under pressure of 30 psig (pund per squard inch) or less, nano-filtering is carried out at room temperature to 80 ℃ under pressure of 50 ~ 300 psig (pund per squard inch) desirable.
다음으로는, 상기와 같이 나노 필터링 처리된 희석액(인산 수용액)을 도 1과 같이 감압증류하여 증류수를 분리, 제거하므로서 고순도의 인산을 회수하는 감압증류 공정을 거친다. 상기 감압증류 공정은 정제된 희석액(인산 수용액)을 인산 농도가 90% 이상인 고순도 인산액으로 농축하는 공정이므로 고점성 인산이 가온에 의해 고분자화 되는 것을 방지하기 위해 상온 내지 150℃의 낮은 온도영역에서 박막 감압 증류법을 채택하는 것이 보다 바람직하다.Next, the nanofiltered diluent (phosphate aqueous solution) is subjected to a vacuum distillation process to recover high purity phosphoric acid by distilling under reduced pressure as shown in FIG. 1 to separate and remove distilled water. The distillation under reduced pressure is a process of concentrating the purified diluent (aqueous phosphate solution) into a high-purity phosphate solution having a phosphoric acid concentration of 90% or more, so that the highly viscous phosphoric acid is polymerized by heating in a low temperature range of room temperature to 150 ° C. It is more preferable to employ a thin film vacuum distillation method.
상기 감압증류 공정에서 나오는 증류수는 앞에서 설명한 증류여액(고농도 인산)의 희석 공정으로 공급하여 재사용 하는 것이 폐기물 감소 및 공정의 연속화에 바람직하다.Distilled water from the distillation under reduced pressure distillation is supplied to the dilution process of the distillation filtrate (high concentration phosphoric acid) described above is preferable for waste reduction and sequencing of the process.
다음으로는, 도 1과 같이 상기 감압증류 공정에서 회수된 고순도의 인산을 사용하여 인산 함유 식각액을 재조성하는 공정을 거쳐 본 발명을 완성한다.Next, the present invention is completed through a process of reconstituting a phosphoric acid-containing etching solution using high purity phosphoric acid recovered in the vacuum distillation process as shown in FIG. 1.
한편, 본 발명에서는 상기와 같이 나노 필터링 처리된 희석액(인산 수용액)을 감압증류 하기전에 선택적으로 (ⅰ)도 2와 같이 나노 필터링 처리된 희석액(인산 수용액)을 전기 활성화 시킨 후 양이온교환수지로 처리하거나, (ⅱ)도 3과 같이 나노 필터링 처리된 희석액(인산 수용액)을 양이온교환수지, 음이온교환수지, 양이 온교환수지와 음이온교환수지의 혼합물 또는 킬레이트 수지도 먼저 처리한 다음 전기 활성화 시키고 다시 양이온교환수지로 처리하거나, (ⅲ)도 4와 같이 나노 필터링 처리된 희석액(인산 수용액)을 전기활성화 시킨 후 양이온교환수지로 처리하고 다시 양이온교환수지, 음이온교환수지, 양이온교환수지와 음이온교환수지의 혼합물 또는 킬레이트 수지로 처리할 수도 있다.Meanwhile, in the present invention, before distillation under reduced pressure of the nanofiltered dilution solution (phosphate aqueous solution) as described above (iii), the nanofiltered dilution solution (phosphate aqueous solution) is electrically activated as shown in FIG. 2 and then treated with a cation exchange resin. Alternatively, (ii) as shown in FIG. 3, the nanofiltered dilution solution (phosphate aqueous solution) is first treated with a cation exchange resin, an anion exchange resin, a mixture of a positive ion exchange resin and an anion exchange resin, or a chelate resin, and then electrically activated. Treatment with cation exchange resin or (iii) electroactivation of nanofiltered diluent (phosphate aqueous solution), followed by treatment with cation exchange resin, followed by cation exchange resin, anion exchange resin, cation exchange resin and anion exchange resin It can also be treated with a mixture of or chelating resins.
나노 필터링 처리된 희석액(인산 수용액)을 전기화학적으로 활성화 시키기 위해서는 특수재질의 전극을 사용하여 상기 희석액(인산 수용액)에 전압이 0.1~10V이며 주파수가 50~1,000,000㎐인 교류를 가해 주는 방법이 바람직하다.In order to electrochemically activate the nano-filtered diluent (aqueous phosphate solution), a method of applying an alternating current having a voltage of 0.1 to 10 V and a frequency of 50 to 1,000,000 kHz to the diluent (aqueous phosphate solution) using an electrode of a special material is preferable. Do.
상기 희석액에 교류 대신에 직류를 가하면 전극표면에 금속이온이 석출되어 전극의 효율이 감소될 수 있다.When a direct current is applied to the diluent instead of an alternating current, metal ions may be deposited on the electrode surface, thereby reducing the efficiency of the electrode.
이때 사용되는 각종 이온교환수지로는 금속화합물의 극미량 이온을 제거하는데 적합한 작용기를 적당한 표면밀도로 갖고 있는 것이 바람직하다.The various ion exchange resins used at this time preferably have a functional group suitable for removing trace ions of the metal compound at a suitable surface density.
이온교환수지를 통과하는 희석액(인산 수용액)의 흐름속도는 1.0 ~ 5.0 sV,보다 바람직하기로는 1.5 ~ 2.5 sV인 것이 좋다.The flow rate of the diluent (phosphate aqueous solution) passing through the ion exchange resin is 1.0 to 5.0 sV, more preferably 1.5 to 2.5 sV.
이상에서 설명한 바와 같이 본 발명은 인산 함유 폐식각액을 감압증류하여 얻어진 증류여액(고농도 인산)을 증류수로 희석시켜 희석액(인산 수용액)을 제조한 다음, 이를 마이크로 필터링 및 나노 필터링 하기 전에 상기 희석액에 착화제 가하여 상기 희석액 내에 포함된 금속화합물들의 이온형태(화학종)을 나노 필터링 방식으로 분리하기에 적합한 이온종으로 변환시켜주기 때문에 상기 금속불순물을 효과적으로 분리, 제거할 수 있다. As described above, in the present invention, a distillation filtrate (high concentration phosphoric acid) obtained by distilling the phosphoric acid-containing waste etching solution under reduced pressure is diluted with distilled water to prepare a dilution solution (aqueous phosphoric acid solution), and then complexed to the diluent before microfiltering and nanofiltering. In addition, since the ionic form (chemical species) of the metal compounds contained in the diluent is converted into ionic species suitable for separation by nano filtering, the metal impurities can be effectively separated and removed.
이하, 실시예 및 비교실시예를 통하여 본 발명을 더욱 구체적으로 살펴본다.Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.
그러나 본 발명은 하기 실시예에만 한정되는 것은 아니다.However, the present invention is not limited only to the following examples.
실시예 1Example 1
TFT-LCD 제조공정에서 방출되는 인산 함유 폐식각액(알루미늄등 금속불순물 함량 : 205ppm)을 감압증류기에 넣고 120℃에서 감압증류하여 질산 등의 증류액을 분리, 제거하여 인산 농도가 93%인 증류여액(고농도 인산)을 얻었다. 이때 분리된 증류액은 인산 함유 식각액의 재조성 공정으로 공급하여 사용하였다.A distillate filtrate with phosphoric acid concentration of 93% is obtained by distilling distillate, such as nitric acid, by distilling under reduced pressure distillation at 120 ℃ by putting the phosphoric acid-containing waste etching liquid (metal impurity content such as aluminum: 205ppm) discharged from TFT-LCD manufacturing process into a vacuum distillation. (High concentration phosphoric acid) was obtained. At this time, the separated distillate was used by feeding to the re-formation process of the phosphoric acid-containing etching solution.
계속해서, 상기 감압증류 공정으로 얻어진 증류여액(고농도 인산)을 증류수로 희석하여 희석액 내 인산의 농도가 15%가 되도록 희석처리하여 희석액(인산 수용액)을 얻었다.Subsequently, the distillation filtrate (high concentration phosphoric acid) obtained by the distillation under reduced pressure was diluted with distilled water, and diluted to obtain a concentration of phosphoric acid in the dilution solution to 15% to obtain a dilution solution (phosphate aqueous solution).
계속해서, 상기 희석액(인산 수용액)에 착화제인 트리부틸 포스페이트를 투입한 후 여기에 전압이 1V이고 주파수가 1,000㎐인 교류를 가하여 착화제가 첨가된 상기 희석액(인산 수용액)을 전기 화학적으로 활성화 하였다.Subsequently, tributyl phosphate as a complexing agent was added to the diluent (aqueous phosphate solution), and an alternating current having a voltage of 1 V and a frequency of 1,000 kHz was added thereto to activate the diluted solution (aqueous phosphate solution) to which the complexing agent was added electrochemically.
계속해서, 착화제가 첨가되고, 전기화학적으로 활성화된 상기 희석액(인산 수용액)을 기공 크기가 0.4㎛인 폴리이미드 다공성 막을 이용하여 20psig(pund per square inch)의 압력으로 상온에서 마이크로 필터링 하였다.Subsequently, a complexing agent was added and the electrochemically activated diluent (aqueous phosphate solution) was microfiltered at room temperature at a pressure of 20 psig (pund per square inch) using a polyimide porous membrane having a pore size of 0.4 μm.
계속해서, 마이크로 필터링된 상기 희석액(인산 수용액)을 기공크기가 0.001㎛인 폴리아미드 다공성 막을 이용하여 300psig 압력으로 상온에서 나노 필터링 하였다.Subsequently, the microfiltered diluent (aqueous phosphoric acid solution) was nanofiltered at room temperature at 300 psig pressure using a polyamide porous membrane having a pore size of 0.001 μm.
계속해서, 상기와 같이 나노 필터링 처리된 희석액(인산 수용액)을 감압증류기에 넣고 100℃에서 감압증류하여 고순도의 인산과 증류액(증류수)를 분리하여, 증류액(증류수)는 상기 희석 공정으로 공급하여 재사용하고, 고순도의 인산은 인산 함유 식각액의 재조성 공정으로 이송하였다.Subsequently, the nanofiltered diluent (phosphate aqueous solution) was put into a vacuum distillation distillation under reduced pressure distillation at 100 ° C. to separate high-purity phosphoric acid and distillate (distilled water), and the distillate (distilled water) was supplied to the dilution process. The phosphoric acid of high purity was transferred to the reconstitution process of the phosphoric acid containing etching liquid.
계속해서, 상기와 같이 회수된 고순도 인산에 상기 인산 함유 폐식각액의 감압증류 공정에서 얻어진 증류액(질산 등의 산화제)과 기타 필요한 화합물을 소량 혼합하여 인산 함유 식각액을 재조성하였다.Subsequently, a small amount of the distillate (oxidizing agent such as nitric acid) obtained in the vacuum distillation step of the phosphoric acid-containing waste etching solution and other necessary compounds were mixed with the high-purity phosphoric acid recovered as described above to reconstitute the phosphoric acid-containing etching solution.
이와 같이 재생된 인산 함유 식각액 내에 녹아있는 알루미늄, 몰리브데늄등의 금속불순물의 함량을 측정한 결과는 표 1과 같다.The results of measuring the contents of metal impurities such as aluminum and molybdenum dissolved in the regenerated phosphoric acid-containing etchant are shown in Table 1.
실시예 2Example 2
TFT-LCD 제조공정에서 방출되는 인산 함유 폐식각액(알루미늄등 금속불순물 함량 : 205ppm)을 감압증류기에 넣고 120℃에서 감압증류하여 질산 등의 증류액을 분리, 제거하여 인산 농도가 93%인 증류여액(고농도 인산)을 얻었다. 이때 분리된 증류액은 인산 함유 식각액의 재조성 공정으로 공급하여 사용하였다.A distillate filtrate with phosphoric acid concentration of 93% is obtained by distilling distillate, such as nitric acid, by distilling under reduced pressure distillation at 120 ℃ by putting the phosphoric acid-containing waste etching liquid (metal impurity content such as aluminum: 205ppm) discharged from TFT-LCD manufacturing process into a vacuum distillation. (High concentration phosphoric acid) was obtained. At this time, the separated distillate was used by feeding to the re-formation process of the phosphoric acid-containing etching solution.
계속해서, 상기 감압증류 공정으로 얻어진 증류여액(고농도 인산)을 증류수로 희석하여 희석액 내 인산의 농도가 15%가 되도록 희석처리하여 희석액(인산 수용액)을 얻었다.Subsequently, the distillation filtrate (high concentration phosphoric acid) obtained by the distillation under reduced pressure was diluted with distilled water, and diluted to obtain a concentration of phosphoric acid in the dilution solution to 15% to obtain a dilution solution (phosphate aqueous solution).
계속해서, 상기 희석액(인산 수용액)에 착화제인 트리부틸 포스페이트를 투입한 후 여기에 전압이 1V이고 주파수가 1,000㎐인 교류를 가하여 착화제가 첨가된 상기 희석액(인산 수용액)을 전기 화학적으로 활성화 하였다.Subsequently, tributyl phosphate as a complexing agent was added to the diluent (aqueous phosphate solution), and an alternating current having a voltage of 1 V and a frequency of 1,000 kHz was added thereto to activate the diluted solution (aqueous phosphate solution) to which the complexing agent was added electrochemically.
계속해서, 착화제가 첨가되고, 전기화학적으로 활성화된 상기 희석액(인산 수용액)을 기공 크기가 0.4㎛인 폴리이미드 다공성 막을 이용하여 20psig(pund per square inch)의 압력으로 상온에서 마이크로 필터링 하였다.Subsequently, a complexing agent was added and the electrochemically activated diluent (aqueous phosphate solution) was microfiltered at room temperature at a pressure of 20 psig (pund per square inch) using a polyimide porous membrane having a pore size of 0.4 μm.
계속해서, 마이크로 필터링된 상기 희석액(인산 수용액)을 기공크기가 0.001㎛인 폴리아미드 다공성 막을 이용하여 300psig 압력으로 상온에서 나노 필터링 하였다.Subsequently, the microfiltered diluent (aqueous phosphoric acid solution) was nanofiltered at room temperature at 300 psig pressure using a polyamide porous membrane having a pore size of 0.001 μm.
계속해서, 나노 필터링된 상기 희석액(인산 수용액)에 전압이 1V이고 주파수가 1,000㎐인 교류를 가하여 상기 희석액(인산 수용액)을 전기화학적으로 활성화 시킨 다음, 이를 양이온 교환수지가 담겨져 있는 탑 내로 통과시켰다.Subsequently, an alternating current of 1 V and a frequency of 1,000 kHz was applied to the nano-filtered diluent (aqueous phosphate solution) to electrochemically activate the diluent (aqueous phosphate solution), and then passed through a tower containing a cation exchange resin. .
이때 희석액(인산 수용액)의 흐름속도는 2.0sV로 하였다.At this time, the flow rate of the diluted solution (phosphate aqueous solution) was 2.0 sV.
계속해서, 상기와 같이 나노 필터링 처리된 희석액(인산 수용액)을 감압증류기에 넣고 100℃에서 감압증류하여 고순도의 인산과 증류액(증류수)를 분리하여, 증류액(증류수)는 상기 희석 공정으로 공급하여 재사용하고, 고순도의 인산은 인산 함유 식각액의 재조성 공정으로 이송하였다.Subsequently, the nanofiltered diluent (phosphate aqueous solution) was put into a vacuum distillation distillation under reduced pressure distillation at 100 ° C. to separate high-purity phosphoric acid and distillate (distilled water), and the distillate (distilled water) was supplied to the dilution process. The phosphoric acid of high purity was transferred to the reconstitution process of the phosphoric acid containing etching liquid.
계속해서, 상기와 같이 회수된 고순도 인산에 상기 인산 함유 폐식각액의 감압증류 공정에서 얻어진 증류액(질산 등의 산화제)과 기타 필요한 화합물을 소량 혼합하여 인산 함유 식각액을 재조성하였다.Subsequently, a small amount of the distillate (oxidizing agent such as nitric acid) obtained in the vacuum distillation step of the phosphoric acid-containing waste etching solution and other necessary compounds were mixed with the high-purity phosphoric acid recovered as described above to reconstitute the phosphoric acid-containing etching solution.
이와 같이 재생된 인산 함유 식각액 내에 녹아있는 알루미늄, 몰리브데늄등의 금속불순물의 함량을 측정한 결과는 표 1과 같다.The results of measuring the contents of metal impurities such as aluminum and molybdenum dissolved in the regenerated phosphoric acid-containing etchant are shown in Table 1.
비교실시예 1Comparative Example 1
희석액(인산 수용액)에 착화제를 투입하지 않은 것을 제외하고는 실시예 1과 동일한 공정 및 조건으로 인산 함유 폐식각액을 정제하여 고순도의 인산을 회수한 다음, 이를 이용하여 인산 함유 식각액을 재조성 하였다.Except that no complexing agent was added to the dilute solution (phosphate aqueous solution), the phosphoric acid-containing waste etching solution was purified in the same process and conditions as in Example 1 to recover high purity phosphoric acid, and then the phosphoric acid-containing etching solution was reconstituted. .
이와 같이 재생된 인산 함유 식각액 내에 녹아있는 알루미늄, 몰리브데늄등의 금속불순물의 함량을 측정한 결과는 표 1과 같다.The results of measuring the contents of metal impurities such as aluminum and molybdenum dissolved in the regenerated phosphoric acid-containing etchant are shown in Table 1.
본 발명은 반도체 및 TFT-LCD 등의 제조 공정에서 발생되는 인산함유 폐식각액을 효율적으로 재생, 사용할 수 있어서 경제적으로 유리함과 동시에 환경오염 방지에도 유리하다.The present invention can efficiently recycle and use the phosphoric acid-containing waste etchant generated in manufacturing processes such as semiconductors and TFT-LCDs, which is economically advantageous and also advantageous in preventing environmental pollution.
특히, 본 발명은 인산함유 폐식각액으로 부터 고순도의 인산을 효율적으로 회수할 수 있는 효과도 있어 실리콘 단결정 웨이퍼 제조공정, 반도체 소자 제조공정, TFT-LCD 제조공정 및 에노다이징 등의 도금공정 등에 유용하게 적용될 수 있다. In particular, the present invention has the effect of efficiently recovering high-purity phosphoric acid from the phosphoric acid-containing waste etching solution, which is useful for silicon single crystal wafer manufacturing process, semiconductor device manufacturing process, TFT-LCD manufacturing process and plating process such as anodizing. Can be applied.
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| KR101122031B1 (en) * | 2005-01-26 | 2012-06-13 | 동우 화인켐 주식회사 | Recovery of phosphoric acid from waste etchant and method of purification for high purity phosphoric acid |
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| JP2011236467A (en) * | 2010-05-11 | 2011-11-24 | Ecocycle Corp | Etching acid waste liquid disposal system, etching acid waste liquid disposal method and etching acid waste liquid disposal apparatus applied thereto |
| CN111675404A (en) * | 2020-03-27 | 2020-09-18 | 绵阳市鑫科源环保科技有限公司 | Spent acid recovery system and method |
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