• Proceedings of the Korean Institute of Resources Recycling Conference
• /
• 2005.10a
• /
• pp.289-297
• /
• 2005

• Journal of the Korean Society for Precision Engineering
• /
• v.23 no.12 s.189
• /
• pp.64-71
• /
• 2006

In this study, to design aluminum scrap recycling equipment, fluid flow and thermal analysis considering electromagnetic phenomenon were carried out by using ANSYS program. The magnetic flux generated by electromagnetic pump has influence on fluid velocity of Al liquid metal with molten metal motion and thermal generation. To investigate the effect of the number of phase on fluid flow and thermal generation, electromagnetic force and magnetic flux were obtained by computer simulation. In addition, the results obtained by fluid flow and thermal analysis, recycling equipment of aluminum scrap with the cooling technology of electromagnetic coil, the most suitable phase and current were proposed.

• Resources Recycling
• /
• v.31 no.1
• /
• pp.46-55
• /
• 2022

The recycling of coated cemented carbide scraps is becoming increasingly significant for the recovery of rare metals. However, coatings consisting of Group IV and V transition metal nitrides are one of the challenging factors in obtaining high-purity materials. We investigated the structural, elastic, and mechanical properties of Group IV and V transition-metal nitrides (TiN, VN, ZrN, NbN, HfN, and TaN) using first-principle calculations. Convergence tests were performed to obtain reliable calculated results. The equilibrium structures of the nitrides were in good agreement with those of a previous study, indicating the reliability of the data. Group IV transition metal nitrides show a higher covalent bonding nature. Thus, they exhibit a higher degree of brittleness than that of Group V transition metal nitrides. In contrast, Group V transition metal nitrides show weaker resistance to shear loading and more ductile behavior than Group IV transition metal nitrides because of the metallic bonds characterized by valence electron concentration. The results of the crystal orbital Hamilton population analysis showed good agreement with the shear resistance tendencies of all transition metal nitrides.

• Proceedings of the Korean Institute of Resources Recycling Conference
• /
• 2004.05a
• /
• pp.74-81
• /
• 2004

• Proceedings of the Korean Institute of Resources Recycling Conference
• /
• 2005.05a
• /
• pp.214-223
• /
• 2005

In order to recover valuable metals from fine-grained electronic waste, bioleaching of Cu, Zn, Al, Co, Ni, Sn and Pb were carried out using Aspergillus niger as a leaching microorganism in a shaking flask. Aspergillus niger was able to grow in tile presence of electronic scrap. The formation of organic acids(citric and oxalic acid) from Aspergillus niger caused the mobilization of metals from waste electronic scrap. In a preliminary study, in order to obtain the data on the leaching of Cu, Zn, Al, Co and Ni, the metal leaching behaviours were accomplished using Organic acid(Citric acid and Oxalic acid) instead of Aspergillus niger. At the electronic scrap concentration of 50g/L, Aspergillus niger were able to leach more than 95% of the available Cu, Co. But Al, Zn, Pband Sn were able to leach about 15-35%. Ni and Fe were detected in the leachate less than 10%.

• Resources Recycling
• /
• v.21 no.4
• /
• pp.26-34
• /
• 2012

Recently, the recovery of resources from waste material of manufacturing electric and electronic equipment has been investigated. It is very important to extract metallic components from electric and electronic manufacturing processes with the view point of recycling of the used resources as well as an environmental protection. In this paper, open/registered patents of US, JP, EP, and KR and SCI journal related to metal recovery technologies from wastes produced in the electric and electronic manufacturing processes between 1975~2011 were reviewed. Patents and papers were collected using key-words searching and filtered by filtering criteria. The trends of the patents and papers were analyzed by the years, countries, companies, and technologies.

• Resources Recycling
• /
• v.17 no.2
• /
• pp.70-75
• /
• 2008

A study on the cementation for the recovery of tin with aluminium in the hydrochloric acid solution was carried out. Parameters, such as aluminium metal equivalent, pH, reaction time, reaction temperature and the concentration of chloride ions were investigated. The experimental results showed that the cementation rate of Sn(II) ions increased with increase of the addition amount of aluminium powders, temperature, pH and the concentration of chloride ions in hydrochloric acid solution. From the results, the optinum conditions for recovery of metallic tin by cementation with aluminium metal powders were proposed.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2015.11a
• /
• pp.217-218
• /
• 2015

주석은 최근 첨단 전기, 전자 제품의 핵심 소재로써 지속적인 수요 증가가 예상되는 전략 금속이다. 국내의 수요량은 2011년 기준 약 17,000톤 으로 99% 이상 수입에 의존하고 있는 실정이다. 그러나, 국내의 주석 제련 산업은 전무한 상태이며 폐자원에서 재활용하는 회수 기술도 초보 단계이다. 이러한 폐자원 발생량은 12,000톤/year이며, 약 1200억원에 달하는 규모이다. 다양한 폐자원의 선별적 전처리 요소 기술 개발 및 회수 공정 시스템 개발이 절실히 요구된다. 본 연구에서는, 주석 폐자원 중 solder 용융물 및 공정 스크랩 Lead solder, Lead-free solder 등 뿐만 아니라, ITO target 제조 시 발생하는 ITO sludge 등의 고상 폐자원으로부터 페자원의 물성을 파악하여 금속/산화물과의 파/분쇄 및 분급공정을 통하여 고품위의 주석 금속을 회수하였다. 뿐만 아니라, 고순도 주석시 발생하는 양극 슬라임 침출액 등의 액상 폐자원으로부터 희소금속의 추출 및 회수를 위해 습식 전처리 공정을 수행하였다. 침출액은 주석, 구리, 납 등의 유가금속이 이온형태로 존재하고 있으며, Chlorine이 다량 함유되어 있다. 고품위의 주석 산화물을 회수하기 위하여 침출액 내의 구리 제거 공정, Chlorine 제거 공정 등을 순차적으로 수행하여 고품위의 산화물 회수를 수행하였다.

• Proceedings of the Korean Institute of Resources Recycling Conference
• /
• 2006.05a
• /
• pp.56-60
• /
• 2006

In 2005, the imports of titanium metals was about 22.8 million US$(7,700 tons) in Korea. New scrap produced was estimated to be 359 tons and the exports were about 352 tons. Generally scrap is recylced into titanium ingot either with or without virgin metal using traditional vacuum-arc-melting and cold hearth melting. In Korea, there is no titanium ingot producers(recyclers). In this paper, the brief summary of major titanium melting technology, such as vacuum arc remelting(VAR), electron beam melting(EBM), plasma arc melting(PAM) is given and discussed. In view of titanium market situation of Korea, the technological development of ingot production from scrap is big problem to be solved in order to realize extensive cost reduction for titanium products.

• Journal of the Microelectronics and Packaging Society
• /
• v.23 no.2
• /
• pp.11-18
• /
• 2016

This study focused on examining the possibility for recycling of Fe-Si electric sheet. We manufactured Fe-6.5Si mother alloy using by Fe-Si electric sheet scrap for transformer core materials. And then, soft magnetic alloy powder which diameter and shape were $45{\sim}150{\mu}m$ and sphere type was prepared by gas atomization process. As we compared to commercial Fe-6.5Si powder, its diameter distribution and microstructure of recycled powder was a similar. To investigate the possibility of reusing the soft magnetic composite sheet for electronics, recycled powder was treated to have a high aspect ratio (AR), and we finally obtained the 65~66 AR and $2.3{\mu}m$ thickness powder. To release the residual stress of powder, heat treatment was conducted under $300{\sim}400^{\circ}C$, $N_2$ gas. And then, soft magnetic sheet was made by tape casting process using by those powders. After the density and permeability of tape was measured, and we confirmed that the recycled Fe-Si electric sheet scrap was possible to reuse the soft magnetic materials of electronics.