• 한국주조공학회지
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• 제36권2호
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• pp.67-74
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• 2016

The effects of scrap content on the hot tearing property and tensile property were investigated in AC2BS alloy. The hot tearing strengths were $16.4kgf/cm^2$, $15.2kgf/cm^2$, $14.9kgf/cm^2$ and $13.3kgf/cm^2$, respectively, under the constant solid fraction of 29.3% when the scrap contents of the specimens were 0%, 20%, 35% and 50%. In the same way, tensile strengths of the as-cast condition were $24.5kgf/mm^2$, $23.7kgf/mm^2$, $17.3kgf/mm^2$ and $16.0kgf/mm^2$, respectively, and the corresponding tensile strengths of the T6 heat treatment condition were $27.2kgf/mm^2$, $26.7kgf/mm^2$, $24.2kgf/mm^2$ and $23.9kgf/mm^2$. Hot tearing strength and tensile strength decreased as scrap content of the specimen increased. According to the evaluation of the quantitative hot tearing and tensile test results, the decrease of these strengths is due to the presence of oxide films which act as crack initiation site of the specimens. Therefore, elimination of oxide films of aluminum melt to maintain melt cleanliness is required.

• Bulletin of the Korean Chemical Society
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• 제34권3호
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• pp.851-855
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• 2013

This paper describes an environmentally friendly process for the recovery of $LiFePO_4$ cathode materials from scrap electrodes by a simple thermal treatment method. The active materials were easily separated from the aluminum substrate foil and polymeric binders were also decomposed at different temperatures ($400^{\circ}C$, $500^{\circ}C$, $600^{\circ}C$) for 30 min under nitrogen gas flow. The samples were characterized by X-ray diffraction (XRD), scanning electronic microscopy (SEM), Raman spectroscopy, Thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The electrochemical properties of the recycled $LiFePO_4$ cathode were evaluated by galvanostatic charge and discharge modes. The specific charge/discharge capacities of the recycled $LiFePO_4$ cathode were similar to those of the original $LiFePO_4$ cathode. The $LiFePO_4$ cathode material recovered at $500^{\circ}C$ exhibits a somewhat higher capacity than those of other recovered materials at high current rates. The recycled $LiFePO_4$ cathode also showed a good cycling performance.

• 대한금속재료학회지
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• 제46권1호
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• pp.13-19
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• 2008

To develop a recycling process of magnesium alloy scrap, a fundamental study on the distillation of magnesium alloy melt was carried out. Melt temperature, vacuum degree and reaction time were considered as experimental variables. The amount of vaporized magnesium melt per unit surface area of melt increases with the increase of melt temperature, reaction time and vacuum degree. The vapor condensed at the tip of water cooling Cu-condenser as a form of pine cone. Magnesium and zinc were vaporized easily from the melt. However, It's difficult to separate magnesium and zinc by vacuum distillation because vapor pressure of zinc is similar to one of magnesium. The contents of aluminum, manganese and iron, etc. in residual melt increase due to the decrease of magnesium and zinc content after the distillation of magnesium alloy.

• 한국재료학회지
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• 제28권12호
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• pp.691-695
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• 2018

In this study, we investigate the recycling of aluminum-based metal matrix composites(AMCs) embedded with SiC particulates. The microstructure of the AMCs is characterized by X-ray diffraction and scanning electron microscopy. The possibility of recycling the composite scrap is attempted from the melted alloy and SiC particulates by re-melting, holding and solidification in crucibles. The recovery percentage of the matrix alloy is calculated after a number of holding times, 0, 5, 10, 15, 20, 25 and 30 minutes and for different particulate sizes and weight fractions in the Al matrix. The results show that the recovery percentage of the matrix alloy, as well as the time required for maximum recovery of the matrix, is dependent on the size and weight fraction of SiC particulates. In addition, the percentage recovery increases with particulate size but drops with the particulate fraction in the matrix. The time to reach maximum recovery falls rapidly with an increase in particulate size and fraction.

• 한국주조공학회지
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• 제20권1호
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• pp.38-45
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• 2000

The remelting for recycling or thin aluminum scrap, such as aluminum chip generally involves melting of these pieces submerged in molten salt flux. In this study, the effects of salt flux compositions and alloying elements on the aluminum dropletscoalescence and oxide film removal were studied in 99.8%Al, Al-1.01%Cu, Al-1.03%Si, and Al-1.38%Mg alloys as a function of holding time at $740^{\circ}C$ Salt fluxes based on NaCl-KCl(1:1) with addition of 5wt.% fluorides(NaF, $Na_3AlF_6$, $CaF_2$) or 5 wt.% chloride($MgCl_2$, $AlCl_3$) were used. The experimental results show that NaCl-KCl(1:1) with addition of 5 wt.% fluorides exhibits better coalescence ability than that with chlorides. The oxide film is not removed by NaCl-KCl(1:1) with addition of 5 wt.%chlorides, while it is removed by NaCl-KCl(1:1) with addition of 5 wt.% fluorides. The aluminum droplets coalescence and oxide film removal by salt fluxes are related to interfacial tension tension between metal and salt flux.

• 자원리싸이클링
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• 제14권4호
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• pp.41-46
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• 2005

알루미늄 폐드로스는 알루미늄 용해 시에 발생되는 주요 폐기물로서 주요 성분은 알루미늄이며 또한 상당량의 금속 알루미늄이 잔류한다. 본 연구에서는 국내 재생 알루미늄업체에서 발생된 알루미늄 폐드로스를 수산화나트륨 용액으로 침출하여 폐드로스 중의 잔류 알루미늄을 용액 상으로 침출, 분리시키고, 침출용액 중에서 알루미늄 성분을 수산화알루미늄으로 회수하였으며 침출 여과 시에 발생된 폐드로스 잔사는 수세, 건조, 배소 과정을 거쳐 알루미나질 세라믹 원료로 재활용하였다. 또한, 1일 4톤의 알루미늄 폐드로스를 처리할 수 있는 규모의 파일롯트 플랜트를 건설하였으며, 시운전을 통하여 개발기술의 재현성을 확인함으로써 연구결과의 상용화 가능성을 제시하였다.

• 공업화학
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• 제17권1호
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• pp.62-66
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• 2006

본 연구에서는 폐 알루미늄을 이용하여 제조한 환경친화형인 발포 알루미늄 기능성 판넬의 특성을 조사하였고, 증점 공정, 교반 혼합 공정, 발포 공정, 냉각 공정을 거쳐 첨색 공정에 의한 제품 품질의 고급화를 추구하였다. 시험은 크게 세 가지로 구분하여 음향투과 손실 시험, 흡음율 측정 시험, 그리고 발포작업조건 및 스크랩 혼합시험을 시행하였다. 그 결과 폐 알루미늄을 이용해 만든 기능성 판넬은 초경량성이며 방음과 차음, 유해전자파 차폐에 탁월하고 약 $2.2kcal/mh^{\circ}C$ 정도로 낮은 열전도율 및 뛰어난 단열효과를 보이는 것으로 나타났다.

• 자원리싸이클링
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• 제28권3호
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• pp.21-25
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• 2019

The utilization of incineration ash from municipal waste must be promoted to solve the social problem on the shortage of final disposal site. In this research, metals should be recovered to avoid the damage of the crushing machine during the utilization of incineration ash in cement industry. In fact, incineration bottom ash from municipal waste contains iron in 3-5%. Nonferrous metal and stainless steel in 1% is also included. The research and development on the physical recovery process was performed not only to remove the metals but also to recover high grade products. Metals were separated from incineration ash in Maruya Co. Ltd.. In fact, iron scrap recovered by magnetic separation can be selled. After that, mixed metal was separated from incineration ash using screen. In this research, mixed metal tried to divided copper, aluminum, brass and stainless steel using drum type magnetic separation, eddy current separation and high magnetic separation. As a result, recovered iron had an 80% for the grade. Aluminum was recovered by eddy current separation without copper and brass.

• 자원리싸이클링
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• 제13권3호
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• pp.50-57
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• 2004

알루미늄 폐드로스는 알루미늄 용해업체에서 발생되는 주요 폐기물 중 하나인데, 주요 성분은 알루미나이며 상당량의 금속 알루미늄이 잔류한다. 알루미늄 폐드로스 내에 잔류하는 금속 알루미늄을 수산화나트륨 용액으로 침출, 분리시켜서 수산화알루미늄으로 제조하는 과정에서 침출잔사가 발생되는데, 침출 후 여과잔사의 주요 성분은 알루미나이다. 본 연구에서는 이 침출잔사를 세척, 건조, 배소하여 알루미나질 캐스타블 내화물과 같은 세라믹 원료로 재활용하는 연구를 수행하였으며, 상용화를 위한 파일롯트 플랜트시험을 수행하였다. 실증 생산라인은 년 간 1,000톤의 폐드로스를 처리하여 약 700톤의 세라믹 원료를 생산할 수 있는 규모이다. 생산라인의 시운전 결과, 개발 기술의 상용화 적용 가능성을 확인하였으며 상용화를 위해서 건조기의 개선과 Na, Fe등 불순 성분들이 시료에 유입되는 것을 줄여야 하는 문제점들을 파악할 수 있었다.

• 산업기술연구
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• 제17권
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• pp.169-174
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• 1997

This investigation was carried out to study on the generation property, management and seperate collection rate of solid waste in the Gu-Gok Falls. Generation rate of solid waste was 80.785kg/day and unit waste generation rates was $65.55g/day{\cdot}tourist$ one person. Physical component of solid waste were garbage 46%, papers 20%, empty bottles 10%, respectively. A plan is required to decrease generation rate of garbage waste. As result to investigate separated garbage can, papers and can were separated more than 60%. But empty bottles and scrap iron were separated less than 50%. P.E.T, steel can, aluminum can and empty bottles were 20% of total generation rate, and profit of reuse is \700,800/year.