• Korean Journal of Construction Engineering and Management
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• v.8 no.1 s.35
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• pp.107-115
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• 2007

Today's human life is more conveniently advantaged and abundant as industrial society advanced. However, the development has been creating a serious environmental crisis. Environmental pollution and exhaustion of natural resources recently became an important issue in construction industry as well as the concern about construction waste management and recycling the resources has arisen. Because the industrial wastes are not only increased quantitatively but also qualitatively intricate and various, groping for ways of reducing the use of resources primarily and recycling is urged on promotion. Currently, only about 33% of the wood wastes produced in construction site are recycled and the others are incinerated or disposed through irregular circulation process. In this study, I will investigate the present status of generating, processing, and recycling construction wood wastes and compare domestic disposal trend to other countries. In addition, I will analyze the actual condition of processing wood wastes in the construction site, verify the irrational causes, and simplify anomalous factors for the purpose of more efficient and correct activation of wood waste treatment and recycling on construction field and protection of environment in the long run.

• Resources Recycling
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• v.23 no.6
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• pp.63-67
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• 2014

Gallium is an important material and is used by industry of oxide semi-conductor and LED chip. However, the most of the gallium-containing waste resources became outflow abroad and the most of which is imported from oversea by following technical problem and low circulation rate. In this research, the recovery of high purity Gallium metal from Gallium scrap, which containing about 30% of Gallium, was investigated by using hydro-metallurgical process. As pretreatment, the Gallium scrap was pulverized and leached by strong acid such as hydro chloric acid. At the leached solution, Indium was separated as an Indium sponge by substitution reaction and then Gallium and Zinc hydroxide separated and filtrated using strong alkaline solution such as sodium hydroxide by precipitation method. Also, Gallium metal and Zinc metal was recovered by electrowinning method. To make an electrolytic solution, Gallium and Zinc hydroxide was leached by strong alkaline solution. Finally, High purity Gallium metal was recovered by vacuum refining process to remove the Zinc impurity.

• Archives of design research
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• v.16 no.2
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• pp.233-242
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• 2003

Whit trade increasingly taking place on the global stale, packaging becomes even more important However, there is only a fine line between the balance of waste created by damaged goods and waste created by over-packaging. A vast quantity of material is used by the packaging industry for the reason of bringing products safely to the customers. In this research I gathered 87 samples of various kinds of confectionery to analyse the actual conditions of the appropriate packaging. As a result, the rate of the needless space excluding actual contents comes to over 60% which clearly says that the most products are over-packaged. Despite assertions from the packaging industry that all packaging is necessary in reducing product waste, the research shows us the fact that it's over-packaged. What needs to be questioned, here, is the level of materials we use in packaging our products, and how we can continue to decrease that amount and recycle what we do use. In the future where materials and resources become more scarce, and therefore more expensive, and the methods of disposal become more costly and accountable, designers and manufacturers constantly need rethink and improve methods of packaging.

• Applied Chemistry for Engineering
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• v.16 no.1
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• pp.28-33
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• 2005

A resource recovery technique using sub- and supercritical water hydrolysis was applied to recover amino aicds from waste fish entrails. The effect of reaction parameters such as temperature and time necessary for the control of reaction towards optimum yield of amino acids was investigated using semi-batch and batch reactors. Results showed a maximum yield of total amino acids (137 mg/g-dry entrails) from waste fish entrails at T=$250^{\circ}C$ (P=4 MPa) and reaction time of 60 min in a batch reactor. Under supercritical conditions (e.g., T=$400^{\circ}C$, P=45 MPa), the yield decreased due to rapid decomposition compared to production rate of amino acids. As a result, the low temperature and the short reaction time were needed to produce a maximum yield of amino acids.

• Resources Recycling
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• v.22 no.2
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• pp.71-77
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• 2013

Electronic products such as appliances, computers, and cellular phones have printed circuit boards (PCBs) in common and the PCBs in the waste electronic products contain valuable metals and organic resins. In Korea, recovery and recycling of the organic resins as well as the valuable metallics from the wastes are required indeed as the most of resources are being imported from abroad. In this article, the patents and papers for the recycling of organic residues from the waste PCBs were collected and analyzed. The open patents of USA (US), European Union (EP), Japan (JP), and Korea (KR) and SCI journals from 1979 to 2012 were investigated. The patents and journals were collected using key-words and filtered by the definition of the technology. The patents and journals were analyzed by the years, countries, companies, and technologies and the technical trends were discussed in this paper. It is showed sluggish relatively activity of published papers and patent applications for polymer manufacturing technology in local and abroad.

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.3
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• pp.207-215
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• 2015

In the last decade, increasing national research fund for recycling the waste FRP (fiber reinforced plastics) ships which has caused environmental problems, improves the technology making concrete-reinforcing fibers out of the waste FRP. Furthermore, the concrete with recycled FRP fiber was tested for the structural performance. Experimental strength tests show that use of recycled FRP powder does not reduce the compressive strength of high strength concrete, and does increase the fire resistance performance of high strength concrete significantly. But, the study in investigating the properties of recycled fiber powder from waste FRP has not been completed because of the absence of the method of separation of mat layer from the waste FRP. This study is to propose a new extracting method of the mat layer from waste FRP, which is the efficient and environment friendly system. and thus it is considered to be the useful recycling method for fire resistance high concrete products or structures.

• Journal of the Korean Society for Marine Environment & Energy
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• v.10 no.3
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• pp.181-186
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• 2007

Despite of environmental problems(safety hazards), mechanical recycling of FRP boats, which involves shredding and grinding of the scrap FRP in a new product. is one of the simpler and more technically proven methods than incineration or reclamation ones. Because FRP is made up of reinforced fiber glass, it is very difficult to break into pieces. It also occurs secondary problem such as air pollution and unacceptable shredding noise level. The another urgent problem which is a serious barrier to FRP recycling is very limited reusable applications. This study is to propose a new method which is efficient and environment friendly waste FRP regenerating system. And it also have shown the polymer cement and fiber-reinforced concrete applications with the waste FRP.

• Resources Recycling
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• v.24 no.4
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• pp.38-49
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• 2015

The importance of recycling came to the fore by increasing of waste electrical and electronic equipment(WEEE) generation. Small WEEE recycling in particular represents a big challenge in Korea because it has various items and components. Main materials of small WEEE are typically well known for metals (copper, iron, aluminum, etc.), PCBs and plastics. Not only Korea but also overseas, the laws for small WEEE were in effect in order to recycle effectively, but the technology is not catched up with the regulation which has to recycle an allocated account of WEEE. In addition, recycling technologies and processes for small WEEE are not developed enough to recycling center properly. In that sense, if we develope the recycling process, have not only technology competitiveness but also resource conservation, improving the environment and economic profits. Therefore, through the analysis of economic value of recycled small WEEE, and current technologies both domestically and internationally, we design conceptual recycling process of small WEEE, and consider the way forward.

• Resources Recycling
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• v.7 no.3
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• pp.27-35
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• 1998

EAF dust generated from electric arc steelmaking process is classified as "hazardous" materials by tbe environmental regulation because of the existence of water leachable heavy metals such as Fe, Zn, Pb, and Cd. However, Fe and Zn among t the elements in the dust can be recovered to high valuable materials by applying a proper process. Therefore, in order to study t the possibility of recovery of iron from EAF dust, the effect oE carbon content and basicity, of synthesized EAF dust on the reduction rate of iron oxide was studied. Experimental results are as follows: TIle softening and melting temperature of the slag w was illcreased with increasing carbon addition amount [or carbon reduction eqUIvalent. At the carbon addition amount of 100% for carbon reduction equivalent and basicity of 1.7, reduction rate of $Fe_2O$ in the slag was the highest. The reaction order fur reduction of $Fe_2O$ by carbon was nearly first order.

• Resources Recycling
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• v.9 no.6
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• pp.45-52
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• 2000

Generally, the residues of EAF's dusts treated by reduction process at high temperature are disposed. If the residues can be recycled as iron sources of EAF by upgrading their iron contents, it can be expected to reduce the amounts of disposed wastes and the environmental impacts. Reduction of EAF's dusts mixed with millscale was carried out in rotary hearth furnace to upgrade iron contents of reduction residues. Dusts should be reduced rapidly to protect from reoxidation of reduced iron residue which can be reoxidized at high temperature. In our experimental conditions, optimum reduction time was about 40min. and iron contents of the residues were increased with increasing mixing ratio of millscale and upgrade to 85% at 50%wt mixing ratio. Zinc and lead contents in residues were about 3% and 0.5% respectively. The residues reduced rapidly must be recycled in EAF because heavy metal elements in the residues can be extracted easily and contaminate air and water.