• 자원리싸이클링
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• 제16권5호
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• pp.3-7
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• 2007

알루미늄 지금 및 스크랩 용해시 발생되는 알루미늄 폐드로스를 사용하여 황산알루미늄(Alum)과 폴리염화알루미늄(pooly Aluminium Chloride: PAC)을 제조하였다. 알루미늄 폐드로스를 황산과 반응시켜 폐드로스 중에 잔류하는 금속알루미늄을 용액 중으로 침출시켜 황산알루미늄 용액으로 제조하였으며, 알루미늄 폐드로스를 염산과 반응시켜 PAC 용액으로 제조하여 수처리응집제로 재활용하고자 하였다. 이와 같이 알루미늄 폐드로스를 재활용함으로써 수산화알루미늄을 원료로 사용하여 황산알루미늄과 PAC를 제조하는 종래의 방법에 비해 제품의 원료비를 줄일 수 있고, 매립 등으로 폐기시켜야 할 폐드로스의 양을 줄이는 효과가 있었다.

• 한국표면공학회지
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• 제28권5호
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• pp.259-266
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• 1995

In order to manufacture an attractive waste glass for the permanent and secure disposal of high-level radioactive waste, the complex composition of the simulated nuclear waste glass PNL-7668 was simplified to a composition of sodium borosilicate glass. The substitutions of $Fe_2O_3$ and $Al_2O_3$ were added to examine on the leaching characteristics of simulated nuclear waste glass with variable composition. The leach tests for these glasses were performed according to 'MCC-1, Static Leach Test Procedure' in acid and basic solution. In this study, for the $Al_2O_3$-containing glasses, Na ion release from these glasses was higher in acid solution than in basic solution. As the content of $Fe_2O_3$ was increased in glasses, Na ion release was increased in acid solution, in spite of decrease of amount of total mass diminution.

• 자원리싸이클링
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• 제29권3호
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• pp.61-74
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• 2020

본 연구에서는 폐형광등 처리 공정의 경제성 확보를 위하여 수행되었으며, 폐형광등 유리의 글래스비드용 원료로서의 사용 가능성, 폐형광체 분말로부터 희토류의 침출, 희토류 침출액으로부터 희토류의 용매추출 가능성 등을 검토하였다. 폐형광체는 산화이트륨 28.9%, 산화세륨이 3.46%, 산화유로퓸 1.95%, 산화터븀 1.76%, 산화란탄 1.43% 순으로 함유되어 있어 회수 및 정제 시 경제성이 충분할 것으로 판단되었다. 폐형광등 유리를 사용하여 글래스비드를 시험 생산 한 결과 그 생산수율과 품질이 우수하여 폐형광등 유리를 글래스비드용 원료로 사용할 수 있을 것으로 판단되었다. 소다배소한 폐형광체를 수침출하면 알루미늄과 규소성분 및 잔류 탄산나트륨 등이 용해하며, 이 수용액에 탄산가스를 불어 넣어 pH를 7 정도로 떨어뜨리면 NaAl₂(CO₃)(OH)₂와 SiO₂ 등이 침전하였다. 자이렌을 희석제로 사용하는 cyanex272-hydrochloric acid, cyanex272-sulfuric acid, D2EHPA-hydrochloric acid, D2EHPA-sulfuric acid, lonquest290-hydrochloric acid, lonquest290-sulfuric acid, p507-hydrochloric acid 조합의 용매추출에서 Y, Eu, Ce, La, Tb의 추출률이 100%에 가깝다. 그러나 동일 조건에서의 원소별 추출률의 차이, 즉 선택성은 16% 이하이다.

• Nuclear Engineering and Technology
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• 제48권3호
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• pp.840-846
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• 2016

Great amounts of solid radioactive waste (second waste) and waste solution are generated from the remediation of uranium-contaminated soil. To reduce these, we investigated washing with a less acidic solution and recycling the waste solution after removal of the dominant elements and uranium. Increasing the pH of the washing solution from 0.5 to 1.5 would be beneficial in terms of economics. A high content of calcium in the waste solution was precipitated by adding sulfuric acid. The second waste can be significantly reduced by using sorption and desorption techniques on ampholyte resin S-950 prior to the precipitation of uranium at pH 3.0.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.259-263
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• 2001

There are several steps such as slicing, lapping, chemical etching and mechanical polishing in the silicon wafer production process. The chemical etching step is necessary to remove damaged layer caused In the slicing and lapping steps. The typical etching liquor is the acid mixture comprising nitric acid, acetic acid and hydrofluoric acid. At present, the waste acid is treated by a neutralization method with a high alkali cost and balky solid residue. A solvent extraction method is applicable to separate and recover each acid. Acetic acid is first separated from the waste liquor using 2-ethlyhexyl alcohols as an extractant. Then, nitric acid is recovered using TBP(Tri-butyl phosphate) as an extractant. Finally hydrofluoric acid is separated with the TBP solvent extraction. The expected recovered acids in this process are 2㏖/l acetic acid, 6㏖/1 nitric acid and 6㏖/l hydrofluoric acid. The yields of this process are almost 100% for acetic acid and nitric acid. On the other hand, it is important to recover and reuse the metal values contained in various industrial wastes in a viewpoint of environmental preservation. Most of industrial products are made through the processes to separate impurities in raw materials, solid and liquid wastes being necessarily discharged as industrial wastes. Chemical methods such as solvent extraction, ion exchange and membrane, and physical methods such as heavy media separation, magnetic separation and electrostatic separation are considered as the methods for separation and recovery of the metal values from the wastes. Some examples of the application of solvent extraction to the treatment of wastes such as Ni-Co alloy scrap, Sm-Co alloy scrap, fly ash and flue dust, and liquid wastes such as plating solution, the rinse solution, etching solution and pickling solution are introduced.

• 한국토양비료학회지
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• 제50권6호
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• pp.606-614
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• 2017

Amount of food waste has been increased annually in Korea and re-use of food waste as a fertilizer or soil amendment in agricultural field has been studied. Therefore, main purpose of this research was to determine optimum condition of hydrolysis for food waste management. Three different solvents, HCl, $H_2SO_4$, and KOH, were used and varied concentration at the range of 10~30% and hydrolysis time at the range of 1~3 hours were evaluated. In general, reduction rate of food waste was increased when concentration of solvent and hydrolysis time was increased except when KOH was used. Among different solvents, concentration, and hydrolysis time, the highest reduction rate (97.79%) was observed when 30% of HCl was used with temperature of $140^{\circ}C$ at 2 hours of hydrolysis time. In addition, neutralization effect of alkalic materials, shell waste (SW) and egg shell (ES) was evaluated. Both SW and ES increased pH of finished acid hydrolysis solution up to 7.61 indicating that neutralization effect of SW and ES was sufficient for finished acid hydrolysis solution. Contents of organic matter was also at the range of 10.7~13.04% and 5.53~8.04% respectively when HCl and $H_2SO_4$ were used as solvent. Overall, hydrolysis technique can be used to manage food waste with selected optimum condition in this study and characteristics of finished hydrolysis solution after neutralization might be suitable for soil amendments.

• 한국물환경학회지
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• 제22권2호
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• pp.288-293
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• 2006

Basic investigations have been carried out for the solvent extraction of silver contained in the waste photographic fixing solution using D2EHPA as an extractant. Extraction experiments were conducted using artificial waste solution which was made by dissolving $AgNO_3$ in distilled water along with actual waste fixing solution. For artificial waste solution, the extraction of silver was found to occur very rapidly at the initial stage of extraction. In addition, more silver was extracted as the volumetric ratio between aqueous phase and organic phase was decreased. The volumetric ratio of organic extractant to diluent was also taken as an influential variable and the extracted amount of silver was observed to decrease with temperature. The characteristics of silver extraction for actual fixing solution was generally similar to that for artificial waste solution. Regarding the kinetic analysis, the extraction of silver contained in the actual solution was observed to follow a first order reaction.

• 자원리싸이클링
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• 제15권5호
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• pp.52-56
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• 2006

국내 알루미늄 재생업체에서 알루미늄 용해시 발생되는 알루미늄 폐드로스를 사용하여 수처리응집제로 사용되는 폴리염화알루미늄(PAC: Poly Aluminium Chloride)를 제조하였다. 알루미늄 폐드로스를 염산과 반응시켜 폐드로스 중에 잔류하는 금속알루미늄을 PAC용액으로 제조함으로써 수산화알루미늄과 염산을 원료로 사용하여 PAC를 제조하는 종래의 방법에 비해 제품의 원료비를 줄일 수 있고, 알루미늄 폐드로스를 재활용함으로써 매립 등으로 폐기시켜야 할 폐드로스의 양을 줄이는 효과가 있다.

• 방사성폐기물학회지
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• 제11권2호
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• pp.85-93
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• 2013

본 연구는 우라늄 변환시설 운전 중에 발생된 우라늄 함유 슬러지를 가열 처리하여 분말 형태로 저장 중인 우라늄 함유 슬러지의 열분해 고체폐기물 (Thermal Decomposed Solid Waste of uranium-bearing sludge : TDSW)을 대상으로 TDSW의 용해, TDSW 질산 용해액의 알카리화에 의한 불순물 제거 및 탄산염 알카리화 용액의 산성화에 의한 U 선택적 제거/회수 특성 등을 규명하였다. TDSW의 용해는 질산용해가 탄산염 산화용해 보다 효과적이었다. 1M 질산에서 TDSW의 약 30wt%가 고체 잔류물로 불용해되었고, TDSW 내 함유 U은 99% 이상이 용해되었다. TDSW의 질산 용해액의 알카리화는 탄산염에 의한 알카리화가 불순물 제거 측면에서 보다 효과적이며, 탄산염 알카리화 (pH 약 9)에서 U과 공용해된 Ca, Al, Zn 및 Fe 등의 $98{\pm}1%$가 제거되었다. 그리고 불순물이 거의 제거된 알카리화 용액 (0.5 M $H_2O_2$ 첨가)의 산성화 (pH 약 3) 에서 U의 99% 이상을 회수할 수 있어 TDSW로부터 U을 선택적으로 제거/회수할 수 있었다.

• 멤브레인
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• 제23권1호
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• pp.92-99
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• 2013

본 연구는 인쇄회로기판(PCB) 제조 시 에칭공정에서 발생되는 구리이온($Cu^{+2}$)을 고농도로 함유한 황산 폐에칭액을 NF 막분리법을 사용하여 에칭액 회수와 구리이온 처리를 효율적으로 수행하기 위한 NF 막여과 공정의 운전 조건을 설정하기 위한 기본 자료를 확보하는데 있다. 이를 위해 미국 Koch사의 SelRO MPS-34 4040 NF 막을 대상으로 구리이온을 고농도(5~25 g/L)로 함유한 모의 황산 폐에칭액의 회분식(dead-end) 나노여과 실험을 수행하여 투과 플럭스와 구리이온의 총괄 배제도를 측정하였다. 이 결과 황산용액에의 막 보관기간이 길수록, 황산용액의 pH가 낮을수록 황산에 의한 NF 막의 손상이 더 크게 발생하여 순수 투과 플러스가 증가하였다. 황산 폐에칭액의 투과 플럭스는 황산용액 내 구리이온의 농도가 증가할수록 막 표면에의 구리이온 농축(농도분극)의 증가에 따라 감소하였으며, 구리이온의 배제도는 구리이온의 농도가 높을수록, pH가 낮을수록, 황산용액 내의 막 보관기간이 길수록 낮아져 초기 37%에서 최소 15% 수준으로까지 감소하였다.