• Title/Summary/Keyword: Recycling technology

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A Study on Estimation of Construction Wastes Units in Urban Development (도시개발지구내 건설폐기물 발생원단위 특성연구)

  • Kim, Sang-Keun;Chung, Ha-Ik;Kwon, Ki-Bum;Yu, Jun
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.1452-1455
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    • 2008
  • In order to establish active and effective recycling plans on construction wastes, the study seeks to built unit generation data per construction waste types on each sector, prepare units data on urban construction waste generation and serve as meaningful data on the establishment of policies on construction waste recycling targeting urban regions. The significance of the study is on the establishment of construction waste recycling plan prior to generation, not as complementary measures on construction waste generated.

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Radiological safety evaluation of dismantled radioactive concrete from Kori Unit 1 in the disposal and recycling process

  • Lee, ChoongWie;Kim, Hee Reyoung;Lee, Seung Jun
    • Nuclear Engineering and Technology
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    • v.53 no.6
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    • pp.2019-2024
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    • 2021
  • For evaluating the radiological safety of dismantled concrete, the process of disposal and recycling of the radioactive concrete generated during the dismantling of Kori Unit 1 is analyzed. Four scenarios are derived based on the analysis of the concrete recycling and disposal process, and the potential exposure to the workers and public during this process are calculated. VISIPLAN and RESRAD code are used for evaluating the dosages received by the workers and public in the following four scenarios: concrete inspection, transport of concrete by the truck driver, driving on a recycled concrete road, and public living near the landfilled concrete waste. Two worker exposure scenarios in the processing of concrete and two public exposure scenarios in recycling and disposal are considered; in all the scenarios, the exposure dose does not exceed the annual dose limit for each representative.

Standardization Status of Rare Earth Elements Recycling in ISO TC 298 (ISO TC 298에서의 희토류 재활용 관련 국제 표준화 현황)

  • Lee, Mi Hye;Song, Yosep;On, Ji Sun;Yoon, Seung Hwan;Han, Munhwan;Kim, Bum Sung;Kim, Taek-soo;Lee, Bin
    • Journal of Powder Materials
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    • v.29 no.2
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    • pp.159-165
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    • 2022
  • Rare earth elements, which are important components of motors, are in high demand and thus constantly get more expensive. This tendency is driven by the growth of the electric vehicle market, as well as environmental issues associated with rare-earth metal manufacturing. TC 298 of the ISO manages standardization in the areas of rare-earth recycling, measurement, and sustainability. Korea, a resource-poor country, is working on international standardization projects that focus on recycling and encouraging the domestic adoption of international standards. ITU-T has previously issued recommendations regarding the recycling of rare-earth metals from e-waste. ISO TC 298 expands on the previous recommendations and standards for promoting the recycling industry. Recycling-related rare earth standards and drafts covered by ISO TC 298, as well as Korea's strategies, are reviewed and discussed in this article.

A Study on the Change of Optical and Mechanical Properties by Reprocessing for High Melt-Indexed Polycarbonate Used in Injection Molded Optical Parts (광학용 사출성형품에 사용되는 고유동성 폴리카보네이트의 재사용에 따른 광학적, 기계적 물성 변화에 대한 연구)

  • Lee, J.H.;Kang, J.J.;Yoon, K.H.;Kim, J.S.
    • Transactions of Materials Processing
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    • v.27 no.4
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    • pp.211-221
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    • 2018
  • To estimate the recycling feasibility of high melt-indexed polycarbonate, 3.5 inch LGP, tensile, flexural and impact specimens were injection-molded and the LGP was shredded into scraps. The scraps were injection-molded again and this process was repeated for 4 times. Properties of the sample, i.e., optical properties, mechanical properties and number average molecular weight were measured at each cycle. Based on the results, as the number of reprocessing increased, transmittance decreased at low wavelength and color coordinate was changed systematically to yellow. Yellow index increased more than twofold during 4 recycling processes. On the other hand, the number average molecular weight decreased during recycling processes. Flexural and impact strength showed no tendency according to the number of recycling, but tensile strength decreased sharply after the third recycling process. Based on these properties, it was concluded that the number of recycling for high melt-indexed polycarbonate allowed in this study was one.

A Study on Management Status of Disposed FRP Fishing Boats and Competitive Advantages of Third Recycling Technology (FRP 폐어선 관리 실태와 재활용 기술 경쟁우위에 관한 연구)

  • Dong-Hun Go;Yeong-Tae Son
    • The Journal of Fisheries Business Administration
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    • v.54 no.3
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    • pp.93-114
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    • 2023
  • Around the 1980s, with government's promotion and dissemination policies for FRP (Fiberglass Reinforced Plastics) of the government as a main material of fishing boats, approximately 97% of the entire fishing boats in Korea have utilized FRP until now. Nevertheless, diverse social and environmental issues have emerged due to the susceptibility to fire and the generation of substances detrimental to human health during the construction process of FRP fishing vessels. Especially, the high disposal cost and the limitation of recycling technology in the disposal process of FRP fishing boats have elicited attention to circular economy. This research intended to grasp the management status and problems of disposed FRP fishing boats in Korea, and to assess the level of competitive advantage of FRP fishing boats' recycling technologies of FRP fishing boats based on VRIO (Value, Rarity, Imitability, Organization) analysis through domestic and foreign management policies and related recycling examples. According to the survey of 161 respondents, including the industry, stakeholders and experts related to the collection, treatment and recycling of fisheries wastes, it was revealed that FRP fishing boats' recycling technologies of FRP fishing boats are at the level of 'unused competitive advantage' that satisfied the level of value, rarity and imitability, but not the level of organization.

Cholesterol Removal from Whole Egg by Crosslinked β-Cyclodextrin

  • Jeong, H.J.;Sun, H.;Chogsom, C.;Kwak, H.S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.27 no.4
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    • pp.537-542
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    • 2014
  • This study was carried out to optimize cholesterol removal in whole egg using crosslinked ${\beta}$-cyclodextrin (${\beta}$-CD) and to recycle the ${\beta}$-CD. Various factors for optimizing conditions were concentration of the ${\beta}$-CD, mixing temperature, mixing time, mixing speed and centrifugal speed. In the result of this study, the optimum conditions of cholesterol removal were 25% crosslinked ${\beta}$-CD, $40^{\circ}C$ mixing temperature, 30 min mixing time, 1,200 rpm mixing speed and $2,810{\times}g$ centrifugal speed. The recycling was repeated five times. The cholesterol removal was 92.76% when treated with the optimum conditions. After determining the optimum conditions, the recyclable yields of the crosslinked ${\beta}$-CD ranged from 86.66% to 87.60% in the recycling and the percentage of cholesterol removal was over 80% until third recycling. However, the cholesterol removal efficiency was decreased when the number of repeated recycling was increased. Based on the result of this study, it was concluded that the crosslinked ${\beta}$-CD was efficient for cholesterol removal in whole egg, and recycling is possible for only limited repeating times due to the interaction of the ${\beta}$-CD and egg protein.

FABRICATION OF U-10WT.%Zr-RE FUEL SLUGS BY RECYCLING OF METALLIC FUEL SCRAPS

  • KI-HWAN KIM;SEUNG-UK MUN;SEONG-JUN HA;SEOUNG-WOO KUK;JEONG-YONG PARK
    • Archives of Metallurgy and Materials
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    • v.65 no.3
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    • pp.1035-1039
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    • 2020
  • U-10wt.%Zr-5wt.%RE fuel slugs for a sodium-cooled fast reactor (SFR) were conventionally prepared by a modified injection casting method, which had the drawback of a low fabrication yield rate of approximately 60% because of the formation of many metallic fuel scraps, such as melt residue and unsuitable fuel slug butts. Moreover, the metallic fuel scraps were classified as a radioactive waste and stored in temporary storage without recycling. It is necessary to develop a recycling process technology for scrap wastes in order to reduce the radioactive wastes of the fuel scraps and improve the fabrication yield of the fuel slugs. In this study, the additive recycling process of the metallic fuel scraps was introduced to re-fabricate the U-10wt.%Zr-5wt.%RE fuel slugs. The U-10wt.%Zr-5wt.%RE fuel scraps were cleaned on the surface impurity layers with a mechanical treatment that used an electric brush under an Ar atmosphere. The U-10wt.%Zr-5wt.%RE fuel slugs were soundly re-fabricated and examined to evaluate the feasibility of the additive process compared with the metallic fuel slugs that used pure metals.

Technical Trends of Rare Metal Recycling in the Next Generation Automobile (차세대 자동차용 희소금속 리싸이클링 기술동향)

  • Hwang, Young-Gil;Kil, Sang-Cheol;Kim, Jong-Heon
    • Resources Recycling
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    • v.23 no.2
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    • pp.3-16
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    • 2014
  • Car exhaust $CO_2$ gas reduction and fuel efficiency of the car lighter for the current era is a big challenge. The developments of high-performance Nd magnets, Li-ion secondary battery and exhaust gas purification performance of PGM catalysts used in the lightweight EV and HEV are activated. Country in order to improve the car lighter and function that use the resources of rare metals are ubiquitous imported from China because of export supply control, as soaring prices have unstable supply and demand. Compared to the emissions from the next-generation automotive recycling, waste scarce resources need to be. This study investigated the recycling technology analysis and development of the information technology, or delivered to the researchers by giving national car industry aims to contribute to the development. Findings, pulmonary high-performance motor vehicle emissions in the exhaust gas purification PGM Catalysts, Li-ion battery and Nd magnets recycling technology, such as pre- and post-processing techniques to classify technology, pre-urban mining technology mechanical separation by screening techniques under development, the study and post-processing technology has, pyro and hydro metallurgical smelting technology is established. Waste Recycling in terms of economic efficiency of mechanical components for the intensive study of screening techniques is needed.

Development of Separation Technology for Adhesively Bonded Hybrid Structures of Metals and Thermoplastic Composites Considering Recycling (재활용을 고려한 금속-열가소성 복합재료 하이브리드 접착 구조의 분리 기술 개발)

  • Han, Soo-Ho;Hwang, Hui-Yun;Bae, Min-Gwan;Park, Sang-Eon;Chang, Hong-Kyu
    • 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.

Trend on Recycling Technologies of Tin Scrap by Material Flows and Patent Analysis (물질흐름 및 특허분석을 통한 주석 스크랩 재활용 기술 동향)

  • Kim, Yong Hwan;Son, Seong Ho;Choi, Han Shin;Han, Chul Woong;Kim, Tae Bum;Ahn, Jae Woo;Kim, Hong In;Lee, Ki Woong
    • 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.