• Resources Recycling
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• v.16 no.3 s.77
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• pp.27-33
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• 2007

It is very important in the view point of resource recycling to recover valuable metals such as copper and tin from waste electric and electronic scrap. The waste electric and electronic scrap contains significant amounts of copper, tin, and so on. In this study, a new process for extracting copper and tin contained in the waste electric and electronic scrap using waste copper slag which is generated from the melting furnace of copper smelter was presented. Advantage of the proposed process is to reuse waste copper slag instead of new fluxes as slag formatives. In each experiment, the waste electric and electronic scrap and waste copper slag were melted inputting suitable amount of CaO as an additional flux. Up to 95% of copper and 85% of tin in the raw material were extracted in a Cu-Fe-Sn alloy phase.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 1993.03a
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• pp.7.1-7
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• 1993

• Resources Recycling
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• v.14 no.2
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• pp.43-55
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• 2005

As world population increases and the world economy expalds, so does the demand for natural resources especially strategic metals such as cobalt. An accurate assesment of the nation's minerals must include not only the resources available in the ground but also those that become available through recycling. In this paper, data on domestic and international supply of cobalt and its applications by end-user were analyzed for stable security of cobalt resources and effective recycling of cobalt scraps. Also, an initial evaluation of the flow of cobalt-containing materials in the United States was prepared. In 2003, 8,000 metric tons of cobalt were consumed in the United States and an estimated 28% of U.S. cobalt supply was derived from scrap. The superalloy industry and catalyst industries have well-established recycling or cobalt recovery practices. Recycling rates of cobalt scraps from magnet alloy and cemented carbide were relatively low.

• Resources Recycling
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• v.18 no.4
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• pp.14-23
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• 2009

In terms of resources recycling and resolving waste disposal problems, it is very important to recover precious metals like Au, Ag and Pd and valuable metals like Cu, Sn and Ni from the scraps of waste electrical and electronic equipment(WEEE) that consists of detective electrical and electronic parts discarded during manufacturing electrical and electronic equipments and waste electrical and electronic parts generated during disassembling them. In general, the scraps of WEEE are composed of various metals and alloys as well as refractory oxides and plastic components. Precious and valuable metals from the scraps of WEEE can be recovered by gas-phase-volatilization, hydrometallurgical, or pyrometallurgical processes. However, the gas-phase-volatilization and hydrometallurgical processes have been suggested but not yet commercialized. At the present time, most of the commercial plants for recovering precious and valuable metals from the scraps of WEEE adopt pyrometallurgical processes. Therefore, in this paper, the technical and environmental aspects on the important pyrometallurgical processes through literature survey are reviewed, and the scale-up result of a new pyrometallurgical process for recovering the precious and valuable metals contained in the scraps of WEEE using waste copper slag is presented.

• Resources Recycling
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• v.7 no.3
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• pp.42-51
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• 1998

Hydrogen in atmosphere can easily dissolve in melt of light metal alloys. Increasing demand for recycling of light metal a alloys has, therefore, focused attention on the removal of hydrogen gas, and alloy addition in melt has become an imporLant r refining process. For this purpose behaviors of mixing and hydrogen degassing in impeller agitated refming vessel with/without barnes were investigated. Flow patterns, mixing time behavior and kinetics of degassing in various agitating conditions were analysed in watet model experiments. And, numerical analysis on turbulent flow pattern in impeller agitated vessels was performed.

• Resources Recycling
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• v.29 no.5
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• pp.3-14
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• 2020

Magnesium is the third most abundant structural metal after aluminum and iron. Magnesium is the lightest metal in the common metals. It has a density 33 % less than aluminum and 77% lower than steel. However, the primary magnesium production process is highly energy intensive. The recycling of magnesium scrap reduces the energy consumption and environmental burden, comparing to the primary metal production. However, the amount of recovered metal from scrap is limited because of the difficulties to remove the impurities in the scrap. This work provides an overview of the magnesium production and recycling process.

• Resources Recycling
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• v.31 no.1
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• pp.46-55
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• 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 Surface Engineering Conference
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• 2016.11a
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• pp.137.1-137.1
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• 2016

반도체, LED, 스마트 정보통신 첨단 기기에는 고가의 비철스크랩을 많이 사용하고 있으나 폐기되고 있는 비철제품을 사용후 반드시 회수되어야 한다. 수출향상을 위해서는 적합한 분리회수 기술의 확보가 필수적이다. 금은 주로 PCB나 반도체, 전자기기, 핸드백이나 가방, 액세서리 등에 주로 사용되고 있으며, 이러한 금을 회수하면 부가가치를 달성할 수 있다. 초기에는 주로 전자제품에 사용 되었으나, 이후 디자인과 기능성부품 등으로 이용이 확대되었다. 현재 국내의 금 사용량과 수요량은 매년 급증하고는 있다. 하지만 가격불안정성과 같은 자원적 문제를 갖고 있을 뿐만 아니라 전량 수입에 의존하고 있다. 국내의 비철회수 현장에서는 W-Mo합금의 박리기술을 제공해 줄 것을 요청하고 있다. 이에 이러한 고가의 스크랩을 체계적으로 회수할 수 있는 기술정보를 제공하고자 한다.

• Resources Recycling
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• v.25 no.2
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• pp.10-16
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• 2016

In this study, the Ni base superalloy was recycled by Argon oxygen decarburization(AOD) process using an inconel 713C scrap. During AOD process, argon gas was continuously injected 1,000 sccm and oxygen gas was injected into 10, 20 and 30 minutes of 100, 250 and 500 sccm.. In early stage of oxygen injection, the oxygen dose increased with increasing Al, Cr, and Mo content and decreasing C content. And Al content was decreased by carburization with added elements in late stage Because of oxidation was occurred with Al, Cr etc. after the reaction of carbon has been finished. From the results, the ratio of ${\gamma}^{\prime}$ phase reduced due to decreasing of Al content for that reason Al is the main element to form the ${\gamma}^{\prime}$ phase. Also carbide reduced owing to decreasing of C content so the mechanical properties of the specimens excessively injected by excess $O_2$ gas were decreased.

• Resources Recycling
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• v.26 no.5
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• pp.22-28
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• 2017

In-Bi-Sn alloy sheet has been used as a thermal fusible parts of secondary battery safety system. This study offers a simple process to make In-Bi-Sn alloy fusible parts. The process consists of two procedures, melting and sheeting by tape casting. 62.5 wt%-In 20.0 wt%-Bi 17.5 wt%-Sn (M.P. $92.4^{\circ}C$) alloy sheet obtained by tape casting was used as the thermal fusible sheet of thermal fuse system for mobile telephone. The performance test of the system was carried out in oil bath, and the fusible alloy sheet was melted and cut off at $95^{\circ}C$. This results confirmed the possibility that the alloy sheet obtained by tape casting can be usable as a thermal fusible parts of battery safety system. And this process can be applied as a simple process to recycle the In-Bi-Sn alloy scrap separated from the used thermal fuse system.