• Resources Recycling
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• v.11 no.5
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• pp.24-29
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• 2002

In this study, to improve the color of iron oxide from waste pickling acid at the cold rolling mill, the quality control technologies especially about color were investigated on the spray roaster and iron oxide powder. At the operation condition of the spray roaster, the charge amount of waste acid per hour, temperature, numbers of spray nozzle were investigated. At admixing process, titanium oxide, silica, goethite were tested. Color character of iron oxide can be improved by process control at spray roaster and by admixing process at a pigment factory Iron oxide from results of this study is enough to use as the colorant of concrete product.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.115-120
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• 1997

Environmental Product Life Cycle Management is an activity for defining and describing the product, process or activity environmentally. Especially, the main responsibility for the environmental impact of products lies in the design phase of product. Designers cany a heavy responsibility to determine technical, economic and ecological properties of the product. So in order to help designers, structured understanding and application of treating large amount of data and infonnation should be considered. This paper presents a methodological approach for decision supporting to build Product Life Cycle Management system and show a set of database modeling. Additionally, a key issue for databases is the quality of the provided information.

• Journal of Applied Reliability
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• v.9 no.4
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• pp.343-349
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• 2009

One of the recent hot issues in the manufacturing business is how to incorporate environmental attributes into product and process design. Design for environment considers the potential environmental impact of a product throughout its life-cycle. In the case of something breaks, it can become waste immediately, hence reliability and durability is the essential part of product design. This paper presents reliability technology for sustainable product design to improve the product longevity that extends performance life, serviceability and durability. The presented method will help to develop a sound design and avoid weak links to minimize the waste.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.693-698
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• 2002

The production accounts of domestic by-product is increased after 1990's. It is worried about the life reduction of dump land, as dump land's capacity have reached to limitation and the amount of construction industrial wastes is going higher. Recently, recycling aggregates could be gained from the reconstruction works using recycle process. And the study and research of recycle concretes developed concrete application methods. It could put some outcome of studies to practical use for concrete products. The methods of crushing waste concrete are going diverse. In this study, the fundamental experiments and recycling application is investigated and analyzed with use of recycling aggregate which made of mechanical crush and underwater electrical impact crush. and the difference between underwater electrical impact crush, mechanical crush and natural aggregates is studied.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.163.3-163
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• 2001

This paper presents the two-step strategy method of performing optimal scheduling of paper mill processes using MINLP (Mixed-Integer Non-Linear Programming) considering the trim loss problem in sheet cutting processes. The mathematical model for a sheet cutting process in the form of MINLP is developed in this study, and minimizing total cost is performed considering the cost of raw paper roll, :hanging cutting patterns, storage of over-product and recycling/burning trim. The paper has been used to deliver and conserve information for a long time, and it is needed to have various sizes and weights ...

• 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.22 no.4
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• pp.46-54
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• 2013

The produced quantity of waste plastics including waste vinyls was assumed as about 5 million tons per year. The quantity of waste vinyls produced from the waste recycling center among total quantity of waste plastics was estimated as about 1 million tons per year. Most of waste vinyls produced from the waste recycling center were recycled as refuse plastic fuel(RPF) or recycled feedstock material. In this study, the medium material using waste vinyls was made by the melting process of heat medium heating and the tensile strength was analyzed for checking the usable possibility of recycled waste vinyl material by comparing with the existent product. In order to use the medium material for producing the recycled product, it can be considered that the tensile strength of medium material is more than 100 $kgf/cm^2$.

• Resources Recycling
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• v.8 no.3
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• pp.31-36
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• 1999

In the process of manufacturing acrylonitrile, azeotrope of water-acetonitrile is formed as by-product. To1uene-ethylacetate mixture was selected as solvent to determine the liquid-liquid equilibria for to1uene(l)-water(2)-acetomtrile(3)-ethyjacetate(4) system. The experimental he-line data were correlated with the UNIFAC model. The distribution and selectivity for quaternary system was also studied.

• Clean Technology
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• v.27 no.2
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• pp.139-145
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• 2021

The purpose of this study is to recover valuable metals from spent batteries using a dry process. We focused on the effect of the smelting temperature on the composition of recovered solid and liquid products and collected gaseous products. After removal of the cover, the spent battery was left in NaCl solution and discharged. Then, the spent battery was made into a powder form through a crushing process. The smelting of the spent battery was performed in a tubular electric furnace in an oxygen atmosphere. For spent lithium-ion batteries, the recovery yield of the solid product was 80.1 wt% at a reaction temperature of 850 ℃, and the final product had 27.2 wt% of cobalt as well as other metals such as lithium, copper, and aluminum. Spent nickel-hydrogen batteries had a recovery yield of 99.2 wt% at a reaction temperature of 850 ℃ with about 37.6 wt% of nickel and other metals including iron. For spent nickel-cadmium batteries, the yield decreased to 65.4 wt% because of evaporation with increasing temperature. At 1050 ℃, the recovered metals were nickel (41 wt%) and cadmium (12.9 wt%). Benzene and toluene, which were not detected with the other secondary waste batteries, were detected in the gaseous product. The results of this study can be used as basic data for future research on the dry recycling process of spent secondary batteries.

• Resources Recycling
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• v.25 no.5
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• pp.44-49
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• 2016

Flue gas desulfurization(FGD) is an effective technique to remove $SO_2$ gases of coal-fired plants. Limestone is usually used as desulfurizing agent. In this study, we use the limestone sludge which is a by-product of steel industry in order to replace desulfurizing agent of FGD process. Physical and chemical characteristics analysis of desulfurizing agent was conducted. Desulfurizing agent using limestone sludge was fabricated by pre-treatment process and, then the agent was used on FGD process. Consequently, the tendency on the $SO_2$ concentration did not appear. And limestone sludge was considered as possible alternative agent for flue gas desulfurization process through absorber control system.