• Applied Chemistry for Engineering
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• v.16 no.6
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• pp.842-847
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• 2005

Virgin NBR and recycled NBR particles, which were pulverized from NBR scraps by high temperature shear-crushing technique, were blended with different mixing ratio. The effects of the recycled NBR content on the cure characteristics and physical properties of these blends were investigated and resistance properties of these blends to heat and various fluids were also studied. The study of cure characteristics showed that the viscosity increased but the scorch time decreased. The physical properties of rubber blends were improved with the addition of the recycled NBR for heat resistance and various fluid tests.

• Elastomers and Composites
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• v.35 no.3
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• pp.227-235
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• 2000

This study focused on the recycling technology and application of waste polyurethane scrap($5{\sim}7mm$) and waste urethane form from the footware scrap. Firstly we suggest the waste polyurethane can be used as a component of medium for hydroponic rose culture. Secondly, recycled thermoplastic polyurethane(RTPU) was produced and blended it with high impact polystyrene(HIPS). And also, in order to extend application of recycling field, the former was produced with adding the amine foaming agent to RTPU/HIPS alloy. The main purpose of this study is to diverse of the recycling of the waste polyurethane.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.268-270
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• 2019

In this paper, we analyzed the papers related to the "4th Industry". In order to analyze the papers, total of 685 papers were collected by searching with the keyword "4th industry" in Korea Journal Index(KCI) from 2016 to 2019. We used Python-based web scraping program to collect papers. As a result of analysis, it was confirmed that artificial intelligence, big data, Internet of things(IoT), digital, network and so on have emerged as the major technologies, and it was confirmed that research has been utilizing the major technologies in various fields related to the 4th industry such as industry, government, education field, and job.

• Korean Journal of Metals and Materials
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• v.46 no.1
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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.

• Journal of the Microelectronics and Packaging Society
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• v.23 no.2
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• pp.11-18
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• 2016

This study focused on examining the possibility for recycling of Fe-Si electric sheet. We manufactured Fe-6.5Si mother alloy using by Fe-Si electric sheet scrap for transformer core materials. And then, soft magnetic alloy powder which diameter and shape were $45{\sim}150{\mu}m$ and sphere type was prepared by gas atomization process. As we compared to commercial Fe-6.5Si powder, its diameter distribution and microstructure of recycled powder was a similar. To investigate the possibility of reusing the soft magnetic composite sheet for electronics, recycled powder was treated to have a high aspect ratio (AR), and we finally obtained the 65~66 AR and $2.3{\mu}m$ thickness powder. To release the residual stress of powder, heat treatment was conducted under $300{\sim}400^{\circ}C$, $N_2$ gas. And then, soft magnetic sheet was made by tape casting process using by those powders. After the density and permeability of tape was measured, and we confirmed that the recycled Fe-Si electric sheet scrap was possible to reuse the soft magnetic materials of electronics.

• Journal of Korea Foundry Society
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• v.36 no.3
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• pp.81-87
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• 2016

In this study, the effect of scrap ratio on the mechanical properties of Zr alloys was studied. Oxygen content in the ingot cake increased rapidly with increasing fraction of scrap, which can be attributed to the surface oxide of scrap including small pieces of turning, chips, etc. Iron content did not increase much with the increasing addition of scrap, suggesting scrap materials was well reserved in the iron-free container. As-cast structure of Zr alloy with the scrap:sponge ratio displayed plate/or needle ${\alpha}$ phase and no appreciable change of the cast structure was observed with change of scrap fraction. The strength increases with increasing fraction of scrap, which can be attributed to the increase of oxygen content. The ductility decreased slightly with increase of scrap fraction. Dislocation-oxygen interaction is known to increase the strength at the expense of ductility. Ingot cake with intentionally added $Fe_2O_3$ exhibited the drastic decrease of the formability, even exhibited the brittle fracture behavior during rolling. The oxidation resistance, however, increased with the increase of scrap fraction because of high oxygen content, which may prevent more penetration and diffusion of oxygen into matrix.

• Resources Recycling
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• v.24 no.1
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• pp.43-50
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• 2015

An extensive literature survey and personal communication with relevant experts made it possible to understand economic and technical feasibility of disposable diaper recycling. Commercial level of soiled diaper recycling technology is currently available from a Dutch company, Knowaste Co., who owns a proprietary separation technology of the pulps, plastics and super absorbing polymer (SAP). In Korea, on the other hand, pre-consumer diaper recycling technology without material separation at its infancy converts manufacturing scraps into refuse plastic fuel (RPF), container/truck cargo boards or automobile boards/sheets. Although previous studies on feasibility of post-consumer recycling in Korea showed mutually contradictory implication, it was found out in this research that significantly positive economic feasibility can be obtained with pre-consumer diaper recycling. Subsequent recycling R&D including pre-consumer scrap and policy support may expedite 'Establishment of Sustainable Society.

• Resources Recycling
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• v.21 no.4
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• pp.26-34
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• 2012

Recently, the recovery of resources from waste material of manufacturing electric and electronic equipment has been investigated. It is very important to extract metallic components from electric and electronic manufacturing processes with the view point of recycling of the used resources as well as an environmental protection. In this paper, open/registered patents of US, JP, EP, and KR and SCI journal related to metal recovery technologies from wastes produced in the electric and electronic manufacturing processes between 1975~2011 were reviewed. Patents and papers were collected using key-words searching and filtered by filtering criteria. The trends of the patents and papers were analyzed by the years, countries, companies, and technologies.

• Journal of Korea Foundry Society
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• v.35 no.4
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• pp.75-79
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• 2015

Commercial Zr-based amorphous alloy was recycled and oxygen was introduced during the recycling process. The oxygen content can have a great effect on the glass forming ability and the mechanical properties of the alloy. Therefore, it was closely examined. The initial oxygen content in the raw material was 1,244 ppm. It was increased to 3,789 ppm in the alloy after ten recycling processes. As the recycling processes were repeated, the oxygen content increased. Specifically, after four recycling processes, it increased sharply as compared to that after three recycling processes. After ten recycling processes, the glass transition temperature (Tg) increased from 613 K to 634 K and the crystallization temperature (Tx) increased from 696 K to 706 K. On the other hand, the super-cooled liquid region (${\Delta}T=Tx-Tg$) decreased slightly from 83 K to 72 K while the reduced glass transition temperature (Trg = Tg/Tm) was 0.63, remaining constant even when the oxygen content was increased. These results indicated that the increased oxygen content deteriorated the glass forming ability. The bending strength as determined in a three-point bending test showed a sharp decrease from 3,055 to 2,062 MPa as the oxygen content was increased from 1,244 ppm to 3,789 ppm; the extension was also decreased from 3.02 to 1.74 mm. These findings meant that the alloy became brittle.

• Resources Recycling
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• v.27 no.1
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• pp.22-30
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• 2018

In order to industrially recycle nickel, cobalt and rare earth elements included in waste NiMH batteries, electrode powder scraps were recovered by dismantle, crushing and classification from automobile waste battery module. As a result of leaching recovered electrode powder scrap with sulfuric acid solution, 99% of nickel, cobalt and rare earth elements were leached under reaction conditions of 1.0 M sulfuric acid solution, pulp density 25 g/L and reaction temperature $90^{\circ}C$ for 4 hours. In addition, the rare earth elements were able to separate from nickel / cobalt solution as cerium, lanthanum and neodymium precipitated under pH 2.0 using 10 M NaOH.