알칼리 용액 중 CaCl₂ 첨가에 의한 텅스텐과 바나듐의 분리

문경혜,최인혁,박경호,강희남,강정신,이진영,Moon, Gyeonghye,Choi, In-hyeok,Park, Kyungho,Kang, Hee-Nam,Kang, Jungshin,Lee, Jin-Young 한국자원리싸이클링학회 2017 資源 리싸이클링 Vol.26 No.4

SCR 폐촉매의 소다배소-수침출 용액으로부터 바나듐과 텅스텐을 분리하기 위한 기초연구를 수행하였다. 침출용액을 모사한 바나듐 $1g{\cdot}L^{-1}$, 텅스텐 $10g{\cdot}L^{-1}$ 합성 알칼리 용액에 NaOH 농도와 $CaCl_2$ 첨가량에 따른 바나듐과 텅스텐의 침전거동을 조사하였다. 또한 이를 바탕으로 반응표면법을 통해 바나듐과 텅스텐의 칼슘 침전에 의한 분리 최적조건을 구하였다. 그 결과 칼슘 침전물로의 반응속도 차이에 기인하여 용액의 온도가 낮으면 바나듐만 선택적으로 침전되었고, 온도가 높아지면 텅스텐 또한 침전되었다. 바나듐과 텅스텐은 NaOH 농도가 높아짐에 따라 침전율이 낮아지며 또한 과량의 칼슘 첨가는 용액의 pH를 낮추어 바나듐과 텅스텐의 침전반응을 촉진시켰다. 반응표면법 분석결과 바나듐과 텅스텐의 분리의 최적조건은 293 K에서 $0.5mol{\cdot}L^{-1}$ NaOH, $CaCl_2$ 1 당량 이며, 이 때 바나듐과 텅스텐의 침전율은 각각 99.5%와 0.0%를 나타냈다. As a fundamental study for the separation of vanadium and tungsten from the leaching solution obtained from the soda roasting and water leaching process of spent SCR (Selective Catalytic Reduction) catalyst was carried out. The precipitation behaviors of vanadium and tungsten using the artificial solution (V: $1g{\cdot}L^{-1}$, W: $10g{\cdot}L^{-1}$) was investigated depending on temperature, NaOH concentration and the amount of $CaCl_2$ (aq.) added. V (aq.) was selectively precipitated at lower temperature than 293 K while tungsten also was precipitated at higher temperature. Precipitation rate of V and W was decreased by the increasing concentration of NaOH. On the other hand, excess Ca addition induced the increase of precipitation rate for V and W due to the formation of $Ca(OH)_2$ following the pH decline. The response surface methodology was employed to optimize the selective precipitation. Vanadium of 99.5% and tungsten of 0.0% was precipitated at $0.5mol{\cdot}L^{-1}$ of aqueous NaOH and 1 equivalent ratio of $CaCl_2$ at 293 K.

연속추출법을 이용한 사격장 오염토양 중 중금속의 화학적 형태 결정

문경혜,박홍기,유경근,김주엽,Moon, Gyeonghye,Park, Hongki,Yoo, Kyoungkeun,Manis Kumar, Jha,Richad Diaz, Alorro,Kim, Ju Yup 한국지하수토양환경학회 2015 지하수토양환경 Vol.20 No.6

The soil sample obtained from shooting area contaminated with Pb, Cu, and Zn was investigated to determine the chemical forms of heavy metals with Tessier’s sequential extraction method, which is constituted of five fractions such as ‘exchangeable’, ‘bound to carbonate’, ‘bound to oxide’, ‘bound to organic matter’, and residual fractions. The amount of organic matter was measured by loss on ignition (LOI) and then the results of ‘bound to organic matter’ and LOI were compared. The sequential extraction results show that 4.7%-45% of Pb, 6.2%-25.9% of Cu and 3.9%-15.3% of Zn belong to the ‘bound to organic matter’ fraction, but LOI result shows that only 1.0%-2.8% of organic matter exists in the soil sample. In heavy medium separation tests, because Pb and Cu extracted in ‘bound to organic matter’ and residual fractions were removed, the heavy metals in the fractions would exist as heavier forms. These results suggest that the part of heavy metal extracted in ‘bound to organic matter’ fraction would result from the oxidation of metallic forms by hydrogen peroxide and nitric acid used in the fraction, and, consequently, that the ‘bound to organic matter’ fraction should be investigated in detail to determine the removal method and treatment capacity when the Tessier’s sequential extraction method is used to examine heavy metal contaminants resulted from elemental metal like bullets.

고순도 산화타이타늄 제조를 위한 탈질폐촉매로부터 타이타늄 회수공정 개발

문경혜 ( Gyeonghye Moon ),최인혁 ( In-hyeok Choi ),강희남 ( Hee-nam Kang ),이태혁 ( Tae-hyuk Lee ),이진영 ( Jin-young Lee ),강정신 ( Jungshin Kang ) 한국폐기물자원순환학회(구 한국폐기물학회) 2018 한국폐기물자원순환학회 춘계학술발표논문집 Vol.2018 No.-

최근 초미세먼지에 의한 환경문제가 대두되면서 주요 원인 중 하나인 발전소 및 자동차 등에서 발생되는 질소산화물 저감에 대한 관심이 높아지고 있다. 이에 따라 발전소를 중심으로 탈질촉매 설치가 증가되고 있으나, 사용수명을 다한 탈질폐촉매의 경우 대부분 매립되고 있어 폐촉매 내 주요 유가금속인 텅스텐, 바나듐 및 타이타늄에 대한 효과적 리싸이클링 공정 개발이 필요한 실정이다. 이에 따라 본 연구에서는 탈질폐촉매 내 타이타늄을 회수하여 고순도 산화타이타늄을 제조하기 위한 공정 개발을 실시하였다. 탈질폐촉매 내 타이타늄을 침출가능한 형태의 화합물로 제조하기 위해 1000 ℃에서 탄산나트륨과 탈질폐촉매를 반응시켜 sodium titanate를 제조하였다. 이를 수침출한 결과, 온도가 증가할수록 탈질폐촉매 내 알루미늄 및 실리콘의 침출률은 증가하였으며 최대 각 94 % 및 89 %의 침출률을 나타내었다. 또한 텅스텐 및 바나듐은 온도에 상관없이 99.5 % 이상의 침출률을 얻을 수 있었으며, 타이타늄은 침출되지 않았다. 타이타늄 침출액을 제조하기 위해 수침출 잔사를 5 - 7 M 염산을 사용하여 60 ℃에서 3시간 침출한 결과, 타이타늄 침출률은 97 %를 나타내었으나 86 - 99 %의 실리콘이 동시에 침출됨을 알 수 있었다. 타이타늄 침출액의 여과성 향상 및 고순도 산화타이타늄 제조를 위해 타이타늄 침출액 내 실리콘을 겔화반응에 의해 제거 후 얻어진 수용액을 90 ℃에서 hydrolysis 반응을 시킨 결과 순도 99.2 % 이상의 산화타이타늄을 제조할 수 있었다.

DIFFRACTIVE EXCITATION OF 14.6, 60 AND 200 A GeV ^16O NUCLEI IN NUCLEAR EMULSION

Kim, C.O.,Moon, K.H.,Park, I.G. 慶尙大學校 기초과학연구소 1990 基礎科學硏究所報 Vol.6 No.-

An angular method of identifying diffractive excitation (DE) events for interactions of hadron beams in nuclear emulsion (Kim C. O. et al. 1980) in nuclear emulsion. The 'apparent' MFP's of DE process are 1.00±0.12, 2.4^+1.6_-0.7, and 2.2±0.4m, respectively, at 200, 60, and 14.6 A GeV, which corresponds to 20~10% of the MFP's of total inelastic interactions. Distinctive features of diffractively excited nuclei, which may explain the Centauro events, are discussed.

Recovery of the Vanadium and Tungsten from Spent SCR Catalyst Leach Solutions by Hydrometallurgical Methods

최인혁,문경혜,전종혁,이진영,라제쉬 쿠마 죠티,Choi, In-Hyeok,Moon, Gyeonghye,Jeon, Jong-Hyuk,Lee, Jin-Young,Jyothi, Rajesh Kumar The Korean Institute of Resources Recycling 2020 資源 리싸이클링 Vol.29 No.2

In new millennium, wide-reaching demands for selective catalytic reduction (SCR) catalyst have been increased gradually in new millennium. SCR catalyst can prevent the NO_x emission to protect the environment. In SCR catalyst the main composition of the catalyst is typically TiO₂ (70~80%), WO₃ (7~10%), V₂O₅ (~1%) and others. When the SCR catalysts are used up and disposed to landfills, it is problematic that those should exist in the landfill site permanently due to their extremely low degradability. A new advanced technology needs to be developed primarily to protect environment and then recover the valuable metals. Hydrometallurgical techniques such as leaching and liquid-liquid extraction was designed and developed for the spent SCR catalyst processing. In a first stage, V and W selectively leached from spent SCR catalyst, then both the metals were processed by liquid-liquid extraction process. Various commercial extractants such as D2EHPA, PC 88A, TBP, Cyanex 272, Aliquat 336 were tested for selective extraction of title metals. Scrubbing and stripping studies were tested and optimized for vanadium and tungsten extraction and possible separation. 3^rd phase studies were optimized by using iso-decanol reagent.

전신마취후 발생한 전율 억제에 대한 Clonidine 의 효과

이명애,문경혜 대한마취과학회 1995 Korean Journal of Anesthesiology Vol.28 No.5

We have studied the efficacy of intravenous clonidine to suppress postoperative shivering. Forty healthy patients who received general anesthesia and required treatment for shivering after operation were allocated randomly to two groups. Group 1 received normal saline 5 ml. Group 2 received 75 mcg intravenous clonidine. 2 minutes, 5 minutes and 10 minutes after treatment, the efficacy of treatment was recorded. Five minutes after treatment, 75 mcg clonidine obliterated shivering in 80% of patients. In contrast, none of the patients treated with normal saline had improved. Mean arterial pressure and heart rate were decreased significantly in patients given 75 mcg intravenous clonindine. But, none of them had required treatment for hypotension or bradycardia. We might say that 75 mcg intravenous clonidine is effective to suppress postoperative shivering without significant side effects.

Vecuronium 과 Atracurium 에 의한 근이완으로 부터의 회복에 미치는 Doxapram 의 효과

이명애,박명혜,문경혜 대한마취과학회 1994 Korean Journal of Anesthesiology Vol.27 No.8

The purpose of this study is to investigate the effects of doxapram on the rates of spontaneous and neostigmine-induced recovery from neuromuscular block with vecuronium and atracurium. Following intravenous injection of either vecuronium (40 patients) or atracurium (40 patients), recovery index (RI) was measured without administering either doxapram or neostigmine (Group 1), or after administration of a combination of neostigmine 40 ㎍/kg and doxapram 1 mg/kg (Group 2), neostigmine 40 ㎍/kg (Group 3) or doxapram 1 mg/kg (Group 4) when twitch tension returned to 25% block of train of four response, each of the four group had 10 patients. The results were such that RI was significantly prolonged after vecuronium in the presence of doxapram compared with Group 1 (13.5 min vs 8.2 min). There was no significant difference in the RI after atracurium in the presence of doxapram compared with Group 1 (7.0 min vs 7.1 min). There was rapid recovery which was significant when neostigmine was administered with or without doxapram (2.4 min vs 2.3 min respectively after vecuronium; 2.3 min vs 2.4 min respectively after atracurium). The authors conclude that administration of doxapram in situation where neuromuscular block with vecuronium is not adequately antagonized does not contribute to rapid recovery from neuromuscular block.

수술 후 환자에서 심부정맥 혈전증 예방을 위한 무릎형 항혈전 스타킹과 허벅지형 항혈전 스타킹의 효과 비교

윤지선(Ji Seon Yun),김은옥(Eun Ok Kim),박희정(Hee Jung Park),문경혜(Kyoung Hye Moon),서유선(Yu Sun Seo),김이영(Lee Young Kim),김연희(Yeon Hee Kim) 한국근거기반간호학회 2013 근거와 간호 Vol.1 No.1

Purpose: Anti-Embolic Stockings (AES) are a valuable means of thromboprophylaxis but it is unclear whether knee or thigh length AES are more effective. The aim of this evidence-based practice activity was to compare knee and thigh length AES after a surgical operation and to examine the effects of each stockings. Methods: RISS, KISS, KoreaMed, PubMed, Ovid and The Cochrane Library were searched to identify relevant original articles. As a result, there was no difference in the prevention of Deep Vein Thrombosis (DVT) between the two groups. But since there is uncertainty, we conducted a non-randomized controlled clinical trial. Data were collected from June, 2013 to September, 2013. Survey and observational data were collected on 57 patients who agreed to participate in the study. Results: There was no difference between knee versus thigh length antiembolic stocking groups in the surrogate outcomes including calf edema, Homan s sign, leg pain of numerical rating scale(NRS) 5 or more, hot flashes leg, and color change in applied site of stocking. And skin complications did not occur in both groups. Conclusion: Knee length AES should be regarded as the stockings of choice for the prevention of DVT in surgical patients. Indeed, they have similar effectiveness as thigh length AES but with better tolerability and lower cost.