• Industrial Engineering and Management Systems
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• v.13 no.1
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• pp.52-66
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• 2014

Promotion of a closed-loop supply chain requires disassembly systems that recycle end-of-life (EOL) assembled products. To operate the recycling disassembly system, parts selection is environmentally and economically carried out with non-destructive or destructive disassembly, and the recycling rate of the whole EOL product is determined. As the number of disassembled parts increases, the recycling rate basically increases. However, the labor cost also increases and brings lower profit, which is the difference between the recovered material prices and the disassembly costs. On the other hand, since the precedence relationships among disassembly tasks of the product also change with the parts selections, it is also required to optimize allocation of the tasks in designing a disassembly line. In addition, because information is required for such a design, the recycling rate, profit of each part and disassembly task times take precedence among the disassembly tasks. However, it is difficult to obtain that information in advance before collecting the actual EOL product. This study proposes and analyzes an optimal disassembly system design using integer programming with the environmental and economic parts selection (Igarashi et al., 2013), which harmonizes the recycling rate and profit using recyclability evaluation method (REM) developed by Hitachi, Ltd. The first stage involves optimization of environmental and economic parts selection with integer programming with ${\varepsilon}$ constraint, and the second stage involves optimization of the line balancing with integer programming in terms of minimizing the number of stations. The first and second stages are generally and mathematically formulized, and the relationships between them are analyzed in the cases of cell phones, computers and cleaners.

• Resources Recycling
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• v.21 no.4
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• pp.76-85
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• 2012

Fluorescent lamps generally involve mercury within their lamp bulbs. Thus if the lamps are disposed as they are, it might cause environmental pollution. On the other hand, as the life of the lamps depends on the degradation of the discharge performance, the fluorescent substance composing the fluorescent substance coating can be recycled by reusing them as the recycled fluorescent substance. Also, the glass material composing the glass bulbs can be reused. The range of search was limited in the open patents of USA (US), European Union (EU), Japan (JP), Korea (KR) and SCI journals from 1977 to 2011. Patents and journals were collected using key-words searching and filtered by filtering criteria. The trends of the patents and journals was analyzed by the years, countries, companies, and technologies. Recovery method of metals from spent fluorescent lamps is mainly the focus on the recovery of precious metals using acid treatment and, detoxification technology is related with controlling process of mercury using a filter system.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.230-235
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• 2001

There are more than 15 millions cars or motors in Taiwan. According to the statistics from Environmental Protection Administration, the number of resulting scrap tires are near 110 thousand tons each year. The tire recycle programs in Taiwan were first conducted in 1989 and executed by ROC Scrap Tire Foundation. However, the current efficiency of the tire recycling industry still needs to be improved to minimize the environmental problem or fire hazards caused by scrap tires storage. Ten major tire-recycling factories are surveyed in this study. The investigations include the source of scrap tire, the shredding process, the market of products, the management of wastes disposal, and the difficulties of these sectors. As the varieties of the shredding machines of the recycle factories, there are three kinds of final products which include powder, granular, and chips. The wastes, wires and fibers, produced by the shredding process are the major problems fur all the factories. The percentage of the wire and fiber removal from rubbers still needs to be increased. The best approaches found in this study to increase the efficiency of scrap tire recycling processes are proposed which include the improvement of magnetic separation system fiber/rubber separation system and the minimization of waste disposal. A categorized standard of the processing outputs is suggested as a reference for the decision-making of the tire-recycling factories.

• Composites Research
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• v.31 no.4
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• pp.128-132
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• 2018

Multi-material design with metals and composites can keep structural functions as well as reduce the weight of automotive parts. However, recycling of automotive parts should be considered due to the increasing emphasis on the environments and pollutions. We derived the key issues for increasing the recycling rate of automotive parts by carrying out a survey targeting representatives and workers related with automotive recycling. The core of the key issues was the separation technology of adhesively bonded metal-composite hybrid structures, so we conducted the basic research and suggested the separation technology which can easily be adopted into the recycling industries.

• Clean Technology
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• v.21 no.4
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• pp.209-216
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• 2015

Indium-Tin-Oxide (ITO) is a material that is widely used for transparent conductive electrodes (TCEs). Indium (In), chief element of the ITO, is expected to be depleted in the near future owing to its high cost and limited reserves. To overcome the issue, ITO has to be retained by recycling redundant ITO targets after manufacturing processes. In this article, we proposed an efficient recycling way of the redundant ITO targets with investigation of the current recycling tendencies in domestic and foreign countries. As a result, it was revealed that only In is recycled from the redundant targets in domestic and Japan. As well, fabrication of TCEs is being researched with ITO nanoparticles solutions. However, since the TCEs fabricated with ITO target is superior to those with other materials, it is thought that establishment of regeneration technology of ITO itself is demanded for an efficient recycling and fabrication of ITO target.

• Resources Recycling
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• v.23 no.3
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• pp.61-70
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• 2014

Tin has been widely used to solder, tin plated steel, bronze alloy, sputtering target for transparent electrode and chemical additives. It has been widely reported to the recycling technologies for tin scraps because of the scarcity and economic efficiency of the reserve. This study was analyzed by using open/registered patents KR, US, CN, JP and EP related to recycling technologies for processing scrap, sludges, waste fluid for plating process and spent alloy containing tin in between 1970 and 2013. Patents were collected using key-words searching and filtered by filtering criteria. The trends of the patents were analyzed by year, country, appliant and technology.

• Resources Recycling
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• v.12 no.3
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• pp.46-53
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• 2003

Recycling of aluminum dross is an important issue in the secondary aluminum industries. In this study, aluminum dross generated in the domestic secondary aluminum industry was processed to use it as raw material for producing alumina refractories. Sample dross was classified according to its size. The dross smaller than 1 mm was leached with sodium hydroxide solution to extract the remained aluminum from the dross into the solution. and then aluminum hydroxide precipitate was recovered from the leach liquor. The waste residue in the leaching was washed, dried and roasted. Most remained metallic components in the residue was changed into oxide through the processes. The roasted dross was made into alumina castable refractories by mixing with aggregates and a binder. Bending strength of the tested castable specimen was over $25\;kg/\textrm{m}^2$ and compressive strength over $80\;kg/\textrm{cm}^2$, which satisfied the Korean Standard value respectively. From the results, it was suggested that this process could be applicable to recycling of aluminum dross.

• Resources Recycling
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• v.17 no.1
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• pp.3-11
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• 2008

The treatment of domestic municipal solid waste has inclined to incineration process instead of disposal in landfills. So, the amount of ash generated by incineration of municipal solid waste is gradually increased. The incineration ash divides into bottom ash and fly ash. The bottom ash which accounts for about 90% of the incineration ash consists of ceramics, glasses and metals. And it can be used as the recycling product by the stabilization process. For example, the bottom ash is used as secondary building material or for other similar purposes such as road sub-bases and noise barrier in USA, Europe and Japan. But, the stabilization-treatment technique of bottom ash sti11leaves much to be desired in Korea. Thus, the domestic study of recycling about bottom ash must be improved through investigation about the chemical property and technique of stabilization.

• Resources Recycling
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• v.28 no.1
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• pp.3-14
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• 2019

Copper is used in many electronic components and construction parts due to its excellent electrical conductivity and heat transfer characteristics, and also used for pre-plating for double layer coating such as nickel, so that copper is an essential material in modern industry. Despite the expected increase of usage and importance on wiring, sensors and data equipment in the next generation industries, it is hard for securing stable copper supply and resource management resulting from the copper prices are fluctuating owing to the economic crisis in Europe, the low economic growth trend in China, and President Trump's commitment to public industrial facilities investment in U.S.. Since most of the domestic copper consumption is used by electrolytic copper cathode, we studied not only copper recycling technology which is being commercialized but also current research trend under the research stage. This study aims to examine the characteristics of each process and the areas where future recycling technology development is required.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.24 no.2
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• pp.65-71
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• 2018

Paper packs, glass bottles, metal cans, and plastic materials are classified according to packaging material recycling groups that are Extended Producer Responsibility (EPR). In the case of waste paper pack, the compressed cartons are dissociated to separate polyethylene films and other foreign substance, and then these are washed, pulverized and dried to produce toilet paper. Glass bottle for recycling is provided to the bottle manufacturers after the process of collecting the waste glass bottle, removing the foreign substance, sorting by color, crushing, raw materializing process. Waste glass recycling technology of Korea is largely manual, except for removal of metal components and low specific gravity materials. Metal can is classified into iron and aluminum cans through an automatic sorting machine, compressed, and reproduced as iron and aluminum through a blast furnace. In the case of composite plastic material, the selected compressed product is crushed and then recycled through melt molding and refined products are produced through solid fuel manufacturing steps through emulsification and compression molding through pyrolysis. In the recycling process of paper packs, glass bottles, metal cans, and plastic materials, the influx of recycled materials and other substances interferes with the recycling process and increases the recycling cost and time. Therefore, the government needs to improve the legal system which is necessary to use materials and structure that are easy to recycle from the design stage of products or packaging materials.