밀리칸 油滴實驗과 그 製置改良에 관한 硏究

柳慶根 서울産業大學校 1985 논문집 Vol.21 No.1

The Extraction of Arsenic from Tailing Using NaOH and NaHS

유경근,왕제필,이광석,박홍기 한국자원공학회 2011 Geosystem engineering Vol.14 No.4

An arsenic leaching test was performed to extract arsenic contaminant from tailing sediment under basic condition with NaHS. The effects of particle size, NaHS concentration,temperature, and agitation speed were investigated to determine optimum leaching condition for the removal of arsenic from the tailing sediment. The leaching rate increases with decreasing the particle sizes of enargite and tailing sediment,which would result from the fact that arsenic distributes uniformly in the enargite and tailing sediment particle. The addition of NaHS accelerated the arsenic leaching rate, and this result suggests that some of arsenic in the tailing would exist as enargite or be bound to enargite. The arsenic leaching rates increased with increasing temperature and agitation speed. The arsenic leaching rates of enargite and tailing sediment were found to be 87% and 63%, respectively, under the conditions;particle size, -75 μm; temperature, 80°C; NaHS concentration,1.5 kmol m-3; NaOH concentration, 1.1 kmol m-3; agitation speed, 400 rpm; pulp density, 5 kg m-3 (enargite) and 25 kg m-3(tailing sediment).

폐(廢)리튬일차전지(一次電池)의 안정적(安定的) 해체(解體)를 위한 연구(硏究)

유경근,김명화,신선명,양동효,강진구,손정수,Yoo, Kyoung-Keun,Kim, Myoung-Hwa,Shin, Shun-Myung,Yang, Dong-Hyo,Kang, Jin-Gu,Sohn, Jeong-Soo 한국자원리싸이클링학회 2007 資源 리싸이클링 Vol.16 No.4

고열 및 파절단에 의하여 폭발위험이 있는 폐리튬일차전지를 재활용하기 위해서는 폐리튬일차전지의 안정적 해체공정이 필수적이다. 본 연구에서는 폐리튬일차전지의 안정적 해체를 위한 최적 방전공정 조건을 연구하였다. $0.5kmol{\cdot}m^{-3}$ 황산용액을 이용하여 안정화를 진행한 결과, $35^{\circ}C$에는 4일째에 그리고 $50^{\circ}C$에는 1일째에 안정적 파쇄가 가능하였으며, 높은 반응온도에서 보다 빠른 안정화 결과를 얻을 수 있었다. 황산만을 사용하여 안정화를 진행할 경우, 재활용 가능한 폐리튬일차전지 금속의 손실이 크기 때문에 황산과 증류수를 이용하여 2단으로 안정화하는 공정을 제안하였으며, $0.5kmol{\cdot}m^{-3}$ 황산으로 6시간 안정화시킨 후, 증류수로 24시간 안정화한 결과, 폐리튬일차전지는 안정적으로 파쇄되었으며 금속의 손실도 적어 향후 재활용공정의 경제성 향상이 가능하다고 판단되었다. Dismantlement of lithium primary batteries without explosion is required to recycle the lithium primary batteries which could be exploded by heating too much or crushing. In the present study, the optimum discharging condition was investigated to dismantle the batteries without explosion. When the batteries were discharged with $0.5kmol{\cdot}m^{-3}$ sulfuric acid, the batteries became inert after 4 days at $35^{\circ}C$ and after 1 day at $50^{\circ}C$, respectively. This result shows that higher temperature accelerates inert of the batteries. Because loss of metals recycled increases when the batteries are discharged only with the sulfuric acid, discharging process using acid solution and water was newly proposed. When the batteries were discharged with water during 24 hours after discharging with $0.5kmol{\cdot}m^{-3}$ sulfuric acid during 6 hours, the batteries discharged were dismantled without explosion. Because decrease in loss of metals was accomplished by new process, the recycling process of the batteries could become economic by the 2-step discharging process.

특허분석에 의한 비소 용도개발 동향 조사

유경근,손정수,김성돈 한국자원공학회 2008 한국자원공학회지 Vol.45 No.4

The patents were surveyed to investigate the application of arsenic. Database was collected using WIPS site. Among the database collected using arsenic as a keyword, 385 patents were selected by investigating titles and abstracts. The patents from 1974 to 2007 were analyzed according to IPC, patent applicant, and uses. The patents related with semiconductor were 58% among the 385 patents. The other applications of arsenic were found to in the field of catalyst, drug, and glass.

염산용액에서의 황동광 침출에 대한 산화환원전위의 영향

유경근,이재천,정진기,손정수 한국자원공학회 2008 한국자원공학회지 Vol.45 No.1

Redox potential dependence of chalcopyrite leaching has been investigated to improve low leaching rate of chalcopyrite and it was reported that there is an optimum redox potential for high leaching rate in relatively low redox potential zone. In the present study, chalcopyrite leaching test was performed in chloride media with ferric ions at 50℃ or 80℃, and the redox potential dependence was investigated. The concentration of copper increases gradually with time, and then rapidly increases after around 20 minutes at 80℃ and after around 7 hours at 50℃, respectively. Oxidation-reduction potential (ORP) decreases with time because ferrous ions are leached from chalcopyrite. Leaching rate of chalcopyrite is much faster in the experiment at 80℃ than at 50℃. There is the highest leaching rate around 440 mV (vs Ag/AgCl), and this result indicates that chalcopyrite leaching depends on redox potential in chloride media.

황동광 간접침출기술의 연구동향

유경근,이재천,정진기,손정수,김수경 한국지구시스템공학회 2008 한국지구시스템 공학회지 Vol.45 No.2

황동광은 황화계동광 중 가장 풍부하여 구리 확보를 위한 주요한 해외자원개발대상이다. 황동광은 건식제련법에 의하여 처리되어왔으나, SO<SUB>2</SUB> 가스 발생 등의 문제가 있어 습식제련법이 연구되어왔다. 이 글에서는 황동광 습식제련법 중 중간생성물을 이용하는 황동광 침출법을 금속을 환원제로 사용하는 방법, 산화환원전위를 조절하는 방법, 배소법, SO<SUB>2</SUB>를 이용하는 방법으로 나누어 고찰하고 관련 연구결과들을 정리하였다.

염산용액에서의 황동광 침출에 대한 산화환원전위의 영향

유경근,이재천,정진기,손정수 한국지구시스템공학회 2008 한국지구시스템 공학회지 Vol.45 No.1

침출속도를 개선하기 위한 방법으로서 황동광 침출의 산화환원전위 의존성이 연구되었고, 상대적으로 낮은 산화환원전위대에서 높은 침출속도를 나타내는 최적전위가 존재한다고 보고되었다. 본 연구에서는 산화제로서 Fe<SUP>3+</SUP> 이온을 포함하는 염산용액을 사용하여 50℃와 80℃에서 각각 침출실험을 진행하고 염산용액에서 황동광 침출의 산화환원전위 의존성을 조사하였다. 구리의 농도는 침출이 진행됨에 따라 증가하였으며, 80℃ 실험에서는 20분 후에, 50℃ 실험에서는 7시간 후에 농도가 급격히 증가하였다. 황동광 침출이 진행됨에 따라서 Fe<SUP>2+</SUP> 이온농도가 증가하여 산화환원전위는 감소하였다. 침출속도는 50℃ 침출실험에 비하여 80℃ 침출실험에서 빠르게 나타났으며, 440 mV(Ag/AgCl)에서 침출속도가 가장 빠른 것을 알 수 있었다. 이 결과는 염산용액에서도 황동광의 침출은 산화환원전위 의존성을 갖는다는 사실을 나타낸다.

사문석으로부터 마그네슘의 黃酸浸出과 물유리의 製造

유경근,김동진,정헌생,김민석,이재천 한국자원공학회 2008 한국자원공학회지 Vol.45 No.3

The optimization of Mg leaching from serpentine and the utilization of leaching residue are required for practical use of CO2 sequestration by carbonation of serpentine. Magnesium was leached from serpentine with sulfuric acid and then glass water was prepared using leaching residue obtained from the leaching test. The effects of concentration of sulfuric acid, temperature and time of leaching, and pulp density on leaching of magnesium were investigated. Leaching efficiency increased to 95% under the optimum conditions; 4.0 M in sulfuric acid, 90°C in temperature, 60 minutes in leaching time, 200 g/L in pulp density. The leaching residue contained about 80% Si and is porous with 350 m2/g in surface area. The effects of NaOH concentration, temperature and time of reaction, pulp density on dissolution rate of the residue were investigated. When glass water was synthesized at room temperature, the SiO2/Na2O ratio in glass water was 3.817. Therefore, the new process in this study was found to be an attractive alternative to conventional processes operated at high temperature.

반려동물 자가진료 금지에 대한 올바른 이해 - 반려동물 자가진료 금지의 의미와 범위, 그리고 목적

유경근,Yu, Gyeong-Geun 대한수의사회 2016 대한수의사회지 Vol.52 No.8

銀 超微粒子의 燒結 擧動에 關한 硏究

유경근 서울産業大學校 1993 논문집 Vol.37 No.1

Sintering of ultra-fine silver particles was investigated. The silver UFPs(Ultra Fine Particle) show low temperature sintering, which is found to be initiated at about 130℃ and finished at around 414℃. It appears that the sintering is governed by the two main diffusion mechanisms; surface diffusion stage [130℃ (~1/7.4 Tm) -280℃ (~1/3.34Tm)] and grain boundary diffusion stage [(280℃-414℃ (~1/2.32Tm)]. The sintered body has much greater micro hardness than that of bulk material. The activation energy was determined to be about 0.17eV based on measurement of electrical resistivity during the progress of sintering.