• Journal of Environmental Health Sciences
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• v.39 no.3
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• pp.248-255
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• 2013

Objectives: The purpose of this paper is to define the level of recycling standards and its process in paper scrap. As pollution is increased by improperly treated paper scrap, the government has recently strengthened the management of the paper scrap. Methods: In this study, the current status of paper scrap recycling was investigated through a 2012 field survey, and the classification and recycling standards for paper scrap in developed countries and institutions were also investigated through a literature review in order to introduce optimal recycling standards. Results: As a result, the contents of contaminants were identified as the most important recycling standard, and the contents of contaminants in paper scrap was measured at less than 1.0% at most companies. The recycling standard for paper scrap was determined to be below 3% contaminants in the case of paper and 5% in the case of board. In this study, recycling stage was determined by considering regulations on resources and practices in the field. Conclusions: The recycling standard for paper scrap was determined to be below 3% and 5% contaminants for paper and board, respectively.

• Resources Recycling
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• v.10 no.5
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• pp.3-7
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• 2001

Indium frequently associated with the semiconductor industry is becoming an important metal element widely used in industry. In this paper, its properties especially in relation to its recovery from scrap are reviewed and discussed. Also presented in this paper is how best indium can be recovered by the hydrometallurgical means.

• Journal of Environmental Science International
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• v.22 no.9
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• pp.1105-1113
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• 2013

This paper attempted to estimate the emissions of HFC-134a from scrap truck as a result of measuring the residual quantities of HFC-134a in air conditioner of scrap truck. We measured the residual amounts in the scrap truck of 138 by applying commercial recover for refrigerants. The average residual rate(disposal-phase emission factor) is reported to be $44.3{\pm}3.3%$ within a confidence interval of 95%. Recent year model trucks exhibit the higher residual rates. Little variation, however, is observed in regard to vehicle size. The HFC-134a emission quantity from scrap truck in 2011 is estimated to be 55,908 $tCO_2$-eq that demonstrates 21.4% increase to compare with that in 2007. As the numbers of truck have increased dramatically during the last two decades, the emissions of HFC-134a from scrap truck would increase sharply in the next coming years. HFC-134a is a very high GWP greenhouse gas. therefore have to reduce the emissions from the scrap truck and need to find ways to recycle. The chemical compositions of refrigerants from scrap truck are quite similar to those of new refrigerants, suggesting that the refrigerants from scrap truck could be reused as refrigerant.

• Journal of Digital Convergence
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• v.12 no.8
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• pp.345-350
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• 2014

The most important decision of process planning for the manufacturing system is the machine selection problem to minimize machining costs. Each machine has its own different machining performance indicating a different fraction of scrap, making the cost of scrap generated by machining is different for each machine. Therefore, when we decide on machine selection, we must consider the machining cost and the cost of scrap generated. This paper describes the statistical model for the fraction of scrap generated by machining and the machine selection algorithm considering the total cost including the machining cost and the cost of scrap generated.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.225-229
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• 2001

There are about 41% (by weight) of scrap tires were pulverized to produce rubber powder and granules in the tire recycling industry of Taiwan. However, the reuse of the by-products, steel and fiber, of the scrap tires still needs to be improved. It is difficult to remove the remaining rubber on the surface of steel or fiber. This problem reduce the availability for further reuse of steel and fiber. In addition to the improvement of magnetic, gravity separation techniques or carbonization process, using cryogenic shredding process to separate rubber and fiber (or steel) had been used as another alternative. Cryogenic shredding process for scrap tires showed many advantages, the objective of this paper is to explore the mechanisms for the cryogenic shredding process of scrap tires. Cryo-SEM is used to investigate the topographic information, in-situ, from room temperature to -195$^{\circ}C$ . One square inch shredded tire chips are prepared for SEM study. The percentage of the shrinkage of rubber is also estimated, ca. 6.7%. Mechanisms of cryogenic shredding effects on the tire chips are discussed. The proper practice of cryogenic shredding process far scrap tires is also suggested.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.1
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• pp.176-181
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• 2008

This paper was studied the possibility on the recycling of the scrap used as the food packaging materials, PP/EVOH/PP multilayer. Recycling study was investigated into thermal and mechanical properties of samples which were mixed PP/EVOH waste plastics scrap with two kinds of compatibilizers. Melt behaviors as thermal property and tensile strength, % strain at break point, and tensile modulus as mechanical properties were investigated into kinds of and the weight ratio of compatibilizers. Mixed PP/EVOH waste plastics shows compatibity when Minanto-s and GMS as compatibilizers are mixed 0.5wt.% over.

• Korean Management Science Review
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• v.27 no.2
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• pp.55-66
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• 2010

In Korea, deap-sea fishing industry plays an important role in a food industry. However, it is in a difficult situation because of the more competitive business environment. Therefore, there is a need to restructure the deap-sea fishing industry by scraping superannuated ships. This paper is designed to present scrap programs for deap-sea fishing industry of Korea. We performed ratio analysis to evaluate financial performance of fishing companies and then applied a mixed integer programming (MIP) model to identify optimal schedule for scraping. The results of the financial ratio analysis indicates that it is legible to provide governmental aid to Atlantic trawl, Northern Pacific trawl, and Indian ocean trawl with minimum required rate of return (MRR) of 3%, and the Atlantic strip fishing industry is qualified to receive the governmental aid with MRR value of 5%. Furthermore, by applying the MIP model to develop scrap planning, we demonstrate how our model can be used to restructure the deap-sea fishing industry of Korea.

• Geomechanics and Engineering
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• v.9 no.4
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• pp.447-464
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• 2015

Millions of scrap tires are discarded annually in Turkey. The bulk of which are currently landfilled or stockpiled. These tires consume valuable landfill space or if improperly disposed, create a fire hazard and provide a prolific breeding ground for rats and mosquitoes. Used tires pose both a serious public and environmental health problem which means that economically feasible alternatives for scrap tire disposal must be found. Some of the current uses of scrap tires are tire-derived fuel, creating barrier reefs and as an asphalt additive in the form of crumb rubber. However, there is a much need for the development of additional uses for scrap tires. One development the creation of shreds from scrap tires that are coarse grained, free draining and have a low compacted density thus offering significant advantages for use as lightweight subgrade fill and backfill material. This paper reports a comprehensive laboratory study that was performed to evaluate the use of a shredded tire-sand mixture as a backfill material in trench conditions. A steel frame test tank with glass walls was created to replicate a classical trench section in field conditions. The results of the test demonstrated that shredded tires mixed with sand have a definite potential to be effectively used as backfill material for buried pipe installations.

• Resources Recycling
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• v.24 no.6
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• pp.45-53
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• 2015

There are few studies on the effects of different sources of PVC scraps generated after the end-of-life PVC products and these scraps are used to prepare PVC products of low quality. In this paper, rigid PVC scraps from different sources such as clothes, pipes, and others were investigated to incorporate into virgin PVC compounds as a part of efforts to recycle various PVC scraps effectively. It was found that the tensile strength and impact strength of the PVC compounds generally decreased with increasing the content of PVC scraps. The impact properties of scrap were in order of CC > PC > RC, tensile strength were PC > CC > RC and Vicat softening temperature shows no specific tendency. CC scraps contents of 50 phr of virgin PVC resin showed 80 %, and PC scrap with 50 phr of virgin resin showed 50% of the mechanical properties with virgin PVC.

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