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).

Optimum Conditions of Dismantlement for Recovery of Valuables from Spent Lithium Primary Batteries

유경근,김홍인,손정수,Yoo, Koungkeun,Kim, Hong-in,Sohn, Jeong-Soo The Korean Institute of Resources Recycling 2019 資源 리싸이클링 Vol.28 No.4

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 reactivity of the batteries decreased after 4 days at $35^{\circ}C$ and after 1 day at $50^{\circ}C$, respectively. This result shows that higher temperature removed the high reactivity 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 한국지구시스템공학회 2008 한국지구시스템 공학회지 Vol.45 No.4

비소에 관련된 용도개발동향을 조사하기 위하여 특허 출원 검색을 실시하였으며, 특허검색 데이터베이스는 국내 WIPS사의 특허검색 사이트를 이용하여 수집하였다. 검색 키워드 ‘비소’로 특허를 검색한 후, 특허제목과 요약문을 분석하여 385건의 비소관련 특허를 선정하였다. 특허 분석은 1974년부터 2007년까지의 특허를 주요 IPC 분류별, 출원인별, 용도별로 분류하여 실시하였다. 비소관련 특허는 반도체 분야에 58%로 가장 많이 출원되어있는 것으로 나타났으며, 이외에도 촉매, 치료제, 유리 등의 다양한 분야에서 비소가 활용되고 있는 것으로 나타났다.

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.

Lithium Ion Battery Recycling Industry in South Korea

유경근 한국자원리싸이클링학회 2023 資源 리싸이클링 Vol.32 No.1

The objective of this article is to summarize the commercial lithium ion battery (LIB) recycling processes in Korea and to suggest new direction for LIB recycling. A representative LIB recycler, SungEel Hitech Co. has successfully operated the LIB recycling process for over 10 years, and new recycling processes were recently proposed or developed by many recycling companies and battery manufacturers. In the new recycling processes, lithium is recovered before nickel and cobalt due to the rapid rise in lithium prices, and metal sulfate solution as final product of recycling process can be supplied to manufacturers. The main problem that the new recycling process will face is impurities, which will mainly come from end-of-life electric vehicles or new additives in LIB, although the conventional processes must be improved for mass processing.

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.

자원순환기술의 미래 발전 방향

유경근 한국폐기물자원순환학회(구 한국폐기물학회) 2021 한국폐기물자원순환학회 심포지움 Vol.2021 No.1

Fe-Ni 합금(合金) 스크랩의 황산(黃酸) 침출액(浸出液)으로부터 Ni와 Fe의 분리(分離)

유경근,김민석,유재민,정진기,이재천,Yoo, Kyoung-Keun,Jha, Manis Kumar,Kim, Min-Seuk,Yoo, Jae-Min,Jeong, Jin-Ki,Lee, Jae-Chun 한국자원리싸이클링학회 2008 資源 리싸이클링 Vol.17 No.1

Cementation and solvent extraction processes were studied to separate nickel and iron ions from the $H_2SO_4$ leaching solution with 47 g/L $Fe(Fe^{2+}/Fe^{3+}=1.03),$, 23.5 g/L Ni and 0.90M $H_2SO_4$ which leached from Fe-Ni alloy. Iron powder was used as a reducing agent for the cementation of Ni ion from the leaching solution. The reduction percentage of Ni ion was $17{\sim}20%$ by adding 4 times stoichiometric amount of iron powder at $60{\sim}80$. This may result from the fact that the cementation of Ni ion occurred after the reduction of $Fe^{3+}$ to $Fe^{2+}$ and the neutralization of $H_2SO_4$ with iron powder. The cementation process was proved to be unfeasible for the separation/recovery of Ni ion from the leaching solution including $Fe^{3+}$ as a major component. $Fe^{2+}$ present in the leaching solution was converted to $Fe^{3+}$ for solvent extraction of Fe ion using D2EHPA in kerosene as a extractant. The oxidation of $Fe^{2+}$ to $Fe^{3+}$ was completed by the addition of 1.2 times stoichiometric amount of 35% $H_2SO_4$. 99.6% $Fe^{3+}$ was extracted from the leaching solution (23.5 g/L $Fe^{3+}$) by 4 stages cross-current extraction using 20 vol.% D2EHPA in kerosene. $NiSO_4$ solution with 98.5% purity was recovered from the $H_2SO_4$ leaching solution of scrapped Fe-Ni alloy. 주요 성분으로서 철$(Fe^{2+}/Fe^{3+}=1.03)$ 47g/L, 니켈; 23.5g/L, 0.90M $H_2SO_4$의 조성을 갖는 철-니켈 합금 스크랩의 황산 침출액으로부터 시멘테이션법과 용매추출법으로 니켈과 철 이온을 분리하는 연구를 수행하였다 침출액으로부터 니켈 이온의 시멘테이션을 위하여 철 분말이 환원제로 사용되었다. $60{\sim}80^{\circ}C$에서 4.0 당량의 철 분말을 투입하였을 때 니켈 이온의 환원율은 $17{\sim}20%$에 불과하였으며, 이것은 니켈 이온의 환원석출이 $Fe^{3+}$의 환원반응과 황산의 중화반응이 완료된 후에 시작되었기 때문이다. 이로부터 주성분으로 $Fe^{3+}$를 함유하고 있는 침출액으로부터 니켈 이온의 분리회수에 있어서 시멘테이션은 비효율적임이 확인되었다. D2EHPA를 추출제로 사용하는 철 이온의 용매추출을 위하여 $Fe^{2+}$는 $Fe^{3+}$로 전환시켰다. 1.2 당량의 35% $H_2O_2$를 첨가함으로서 침출액에 존재하는 모든 $Fe^{2+}$는 $Fe^{3+}$로 산화되었다. 20 vol.% D2EHPA를 사용하여 cross-current 방식으로 침출액(23.5 g/L $Fe^{3+}$)으로부터 $Fe^{3+}$의 용매추출을 행하였을 때, 4단 추출에서 99.6%의 $Fe^{3+}$를 추출하여 제거할 수 있었으며 순도가 98.5%인 황산니켈 용액이 얻어졌다