• Nuclear Engineering and Technology
• /
• 제44권7호
• /
• pp.767-772
• /
• 2012

In support of optimizing electrorefining technology for treating spent nuclear fuel, lithium drawdown has been investigated for separating actinides from molten salt electrolyte. Drawdown reaction selectivity is a major issue that requires investigation, since the goal is to remove actinides while leaving the fission products and other components in the salt. A series of lithium drawdown tests with surrogate fission product chlorides was run to obtain selectivity data with non-radioactive salts, develop a predictive model, and draw conclusions about the viability of using this process with actinide-loaded salt. Results of tests with CsCl, $LaCl_3$, $CeCl_3$, and $NdCl_3$ are reported here. Equilibrium was typically achieved in less than 10 hours of contact between lithium metal and molten salt under well-stirred conditions. Maintaining low oxygen and water impurity concentrations (<10 ppm) in the atmosphere was observed to be critical to minimize side reactions and maintain stable salt compositions. An equilibrium model has been formulated and fit to the experimental data. Good fits to the data were achieved. Based on analysis and results obtained to date, it is concluded that clean separation between minor actinides and lanthanides will be difficult to achieve using lithium drawdown.

• 자원리싸이클링
• /
• 제22권4호
• /
• pp.62-69
• /
• 2013

$Li(NCM)O_2$계 폐리튬전지 공정 스크랩의 재활용 연구의 일환으로서 리튬화합물의 회수와 NCM전구체를 제조하기 위한 침출거동에 대하여 살펴보았다. 우선 탄소를 이용하여 층상 구조의 NCM계 산화물 분말을 분해시켰으며, $600^{\circ}C$ 이상의 탄소반응으로 리튬은 탄산리튬으로 변화시켰다. 탄산리튬은 수세 후 농축과정을 거쳐 순도 99% 이상의 탄산리튬 분말로 회수하였다. 그리고 탄소에 의한 환원 반응율은 $800^{\circ}C$에서 약 88%을 나타내었으며, 탄소환원 처리 후 분말에 대한 황산 침출 결과, 2M 이상의 황산농도에서 코발트, 니켈, 망간의 침출율은 99% 이상이었다.

• 자원리싸이클링
• /
• 제33권2호
• /
• pp.24-36
• /
• 2024

리튬이온전지 재활용 공정은 직접 재활용, 습식제련공정, 건식제련공정으로 분류되어 왔으며, 습식제련공정 기반 상용공정은 해체, 파분쇄, 열처리, 선별 등으로 구성된 전처리 공정으로 블랙매스를 생산하고 습식제련공정으로 각 금속을 회수한다. 개발 중인 모든 리튬이온전지 재활용공정은 전구체 원료 제조를 위해 전처리공정 후 침출 등의 습식제련공정을 진행하기 때문에 이 글에서는 재활용공정의 전처리공정에 따른 분류법을 제시하였다. 현재 개발 중인 주요 공정은 황산염배소, 탄소열환원, 합금제조 등이며, 전처리공정에서 미이용 부산물의 활용이 가능할 경우 리튬이온전지 재활용 공정의 경제성 향상이 가능하리라 판단된다.

• 한국방사성폐기물학회:학술대회논문집
• /
• 한국방사성폐기물학회 2005년도 Proceedings of The 6th korea-china joint workshop on nuclear waste management
• /
• pp.86-91
• /
• 2005

A metal product obtained from an electrolytic reduction process, possesses less volume and radioactivity than those of the unprocessed spent oxide fuels. The chemical composition of the metal product varies according to the process condition. In this work, a basic study was performed to evaluate the chemical forms of the spent oxide fuel components in an electrolytic reduction process with the operation conditions. One of the most important operation conditions is the cell potential applied for the reduction cell. It is expected that $PU_{2}O_3$ is difficult to reduce even though the cell potential is negative enough to reduce the lithium oxide when the activity of $Li_{2}O$ exceeds 0.003. The reduction of actinide oxides via the reduction of $Li_{2}O$ is assumed to have a greater reduction yield than a direct reduction of the actinide oxides.

• 한국원자력학회:학술대회논문집
• /
• 한국원자력학회 2004년도 추계학술발표회 발표논문집
• /
• pp.767-767
• /
• 2004

• 한국원자력학회:학술대회논문집
• /
• 한국원자력학회 2002년도 춘계공동학술발표회요약집
• /
• pp.270-270
• /
• 2002

• 한국재료학회지
• /
• 제22권1호
• /
• pp.8-15
• /
• 2012

Silicon-based thin film was prepared at room temperature by an electrochemical deposition method and a feasibility study was conducted for its use as an anode material in a rechargeable lithium battery. The growth of the electrodeposits was mainly concentrated on the surface defects of the Cu substrate while that growth was trivial on the defect-free surface region. Intentional formation of random defects on the substrate by chemical etching led to uniform formation of deposits throughout the surface. The morphology of the electrodeposits reflected first the roughened surface of the substrate, but it became flattened as the deposition time increased, due primarily to the concentration of reduction current on the convex region of the deposits. The electrodeposits proved to be amorphous and to contain chlorine and carbon, together with silicon, indicating that the electrolyte is captured in the deposits during the fabrication process. The silicon in the deposits readily reacted with lithium, but thick deposits resulted in significant reaction overvoltage. The charge efficiency of oxidation (lithiation) to reduction (delithiation) was higher in the relatively thick deposit. This abnormal behavior needs to clarified in view of the thickness dependence of the internal residual stress and the relaxation tendency of the reaction-induced stress due to the porous structure of the deposits and the deposit components other than silicon.

• 방사성폐기물학회지
• /
• 제19권2호
• /
• pp.225-231
• /
• 2021

The reaction between Li₂CO₃ and Cl₂ was investigated to verify its occurrence during a carbon-anode-based oxide reduction (OR) process. The reaction temperature was identified as a key factor that determines the reaction rate and maximum conversion ratio. It was found that the reaction should be conducted at or above 500℃ to convert more than 90% of the Li₂CO₃ to LiCl. Experiments conducted at various total flow rate (Q) / initial sample weight (W_i) ratios revealed that the reaction rate was controlled by the Cl₂ mass transfer under the experimental conditions adopted in this work. A linear increase in the progress of reaction with an increase in Cl₂ partial pressure (pCl₂) was observed in the pCl₂ region of 2.03-10.1 kPa for a constant Q of 100 mL·min^-1 and W_i of 1.00 g. The results of this study indicate that the reaction between Li₂CO₃ and Cl₂ is fast at 650℃ and the reaction is feasible during the OR process.

• 한국분말재료학회지
• /
• 제21권2호
• /
• pp.131-136
• /
• 2014

Cathode materials and their precursors are prepared with transition metal solutions recycled from the the waste lithium-ion batteries containing NCM (nickel-cobalt-manganese) cathodes by a $H_2$ and C-reduction process. The recycled transition metal sulfate solutions are used in a co-precipitation process in a CSTR reactor to obtain the transition metal hydroxide. The NCM cathode materials (Ni:Mn:Co=5:3:2) are prepared from the transition metal hydroxide by calcining with lithium carbonate. X-ray diffraction and scanning electron microscopy analyses show that the cathode material has a layered structure and particle size of about 10 ${\mu}m$. The cathode materials also exhibited a capacity of about 160 mAh/g with a retention rate of 93~96% after 100 cycles.

• 자원리싸이클링
• /
• 제31권1호
• /
• pp.12-20
• /
• 2022

폐리튬이온전지를 용융환원시키면 구리, 코발트, 철, 망간, 니켈 및 규소를 함유한 금속합금을 얻는다. 금속합금의 황산침출용액에서 상기 금속을 분리하기 위한 공정을 개발하여 발표하였다. 이 공정에서는 철(III)과 구리(II)를 분리하기 위해 이온성액체를 사용하였다. 본 연구에서는 이온성액체를 대체하기 위해 D2EHPA와 Cyanex 301을 추출제로 사용했다. 철(III)과 구리(II)는 황산침출액으로부터 0.5 M의 D2EHPA에 의한 3단의 교차추출 및 0.3 M의 Cyanex 301로 분리하는 것이 가능했다. 유기상으로부터 철(III)과 구리(II)의 탈거는 각각 50%와 60%의 왕수로 가능했다. 연속실험의 물질수지로부터 금속의 회수율과 순도는 99%이상으로 확인되었다.