• Journal of the Korea Concrete Institute
• /
• v.19 no.6
• /
• pp.667-676
• /
• 2007

As the 21st century began, cement and concrete that are representatives of modem building materials became a major factor in global warming, air pollution and environmental pollution. Also, the problems that are generated while pursuing high performance and high strength became social issues. Therefore, it has become urgent to prepare counter plans. This study has aimed at the recycling of sewage sludge ash and developing it as a new concept in building material which serves the environmental considerations for long-lasting developmental purpose. Also, the study aimed to find a substitute for scarce natural resources and to secure high techniques for waste recycling. The purpose of this study was also to solve fundamentally secondary environmental pollution. The results revealed that the chemical components of sewage sludge ash are mainly $SiO_2\;and\;Al_2O_3$ which are similar to the components of pozzolan. Also, it was identified that sewage sludge ash can be utilized as a hardened specimen with an alkali activated pozzolan reaction. Considering the possibility of appropriate strength development and the advantage of drying shrinkage, compared with that of cement, it was believed that sewage sludge ash can demonstrate a function as a substitute for cement given.

• Clean Technology
• /
• v.23 no.3
• /
• pp.256-269
• /
• 2017

In response to national and international regulations for resource circulation and to reduce greenhouse gas emissions, the automotive industry has tried to reuse scrap parts and defective products produced in the disposal or production stages as recycled resources. Attempts have been made to reach the target recycling rate by reducing the number of material types required for each part. Moreover, in order to achieve greenhouse gas reduction targets while maintaining the performance of existing products, lighter components are being developed. Existing products were 100% incinerated at the disposal stage, but the uni-materialized products were improved to be possible that it could be recycled 90% through scraps and the defective product in the pre-production and production stage. It also appears that the fuel efficiency improves through 56% lightweight compared to the existing product. In this paper, a preliminary assessment is conducted on the applicability of uni-materialized product development of car parts. The environmental impact values of existing products and developed prototypes are compared and analyzed through life cycle assessment.

• Resources Recycling
• /
• v.22 no.3
• /
• pp.73-80
• /
• 2013

Metal prices are rapidly rising due to increasing demand of metals and limited available resources according to the industrial requirement. As a result, securing a stable supply of these metal resources has been recognized as a core element of national competitiveness and sustained economic growth. In the case of magnesium and its alloys which are entirely depending on import, low-grade magnesium scraps from end-of-life vehicles and 3C(Camera, Computer, Communication) parts and magnesium wastes such as sludge and dross generated during melting process are hardly recycled. Accordingly, the development and commercialization of recycling technology of low-grade magnesium scrap is desperately needed to improve efficiency of resource circulation and to establish the required proprietary of resource metal supply and demand. In this study, papers and patents on recycling technologies of waste magnesium were analyzed. The range of search was limited in the open patents of USA (US), European Union (EP), Japan (JP), Korea (KR) and SCI journals from 1974 to 2012. Patents and journals were collected using key-words searching and filtered by filtering criteria. The trends of the patents and journals was analyzed by the years, countries, companies, and technologies.

• Clean Technology
• /
• v.25 no.3
• /
• pp.179-188
• /
• 2019

Upon the combustion of coal particles in a coal-fired power plant, fly ash (80%) and bottom ash (20%) are unavoidably produced. Most of the ashes are, however, just dumped onto a landfill site. When the landfill site that takes the fly ash and bottom ash is saturated, further operation of the coal-fired power plant might be discontinued unless a new alternative landfill site is prepared. In this study, wet flotation separation system (floating process) was employed in order to recover unburned carbon (UC), ceramic microsphere (CM) and cleaned ash (CA), all of which serving as useful components within fly ash. The average recovered fractions of UC, CM, and CA from fly ash were 92.10, 75.75, and 69.71, respectively, while the recovered fractions of UC were higher than those of CM and CA by 16% and 22%, respectively. The combustible component (CC) within the recovered UC possessed a weight percentage as high as 52.54wt%, whereas the burning heat of UC was estimated to be $4,232kcal\;kg^{-1}$. As more carbon-containing UC is recovered from fly ash, UC is expected to be used successfully as an industrial fuel. Owing to the effects of pH, more efficient chemical separations of CM and CA, rather than UC, were obtained. The average $SiO_2$ contents within the separated CM and CA had a value of 53.55wt% and 78.66wt%, respectively, which is indicative of their plausible future application as industrial materials in many fields.

• The monthly packaging world
• /
• no.8 s.184
• /
• pp.54-58
• /
• 2008

골판지 포장산업은 내수산업 특성을 지닌 주문생산 산업으로 과당경쟁이 심한 저부가가치 산업으로 부피가 커 수요지 중심 분산분포형의 전형적인 중소기업형 산업이다. 특히 골판지 포장산업은 폐지를 95%이상 재활용하는 대표적인 친환경 소재산업이며 국내 종이 생산 최다지종(35%)으로 대표적 제지분야이다. 본고에서는 한국골판지포장공업협동조합이 올해 발표한 자료를 토대로 국내 경기 전망을 살펴보고 골판지 포장생산 현황과 시장동향 등에 대해 살펴보도록 한다.

• Proceedings of the Korean Fiber Society Conference
• /
• 2002.04a
• /
• pp.211-214
• /
• 2002

셀룰로오즈/아민 옥사이드(NMMO) 수화물 계로부터 제조되는 Lyocell 섬유는 기존의 재생 셀룰로오즈 섬유에 비해 우수한 인장특성과 촉감을 가지고 있다. 특히 이것은 용매의 무독성, 재활용 및 부산물 억제와 같은 환경 친화적인 제조공정으로 인하여 새로운 섬유 소재로 부각되고 있다[1]. 그러나 높은 배향도와 피브릴간의 약한 결합력으로 인하여 섬유 표면의 과도한 피브릴이 형성되고 이는 염색가공시 많은 문제를 일으키는 것으로 알려져 있다. (중략)

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 1996.06a
• /
• pp.63-73
• /
• 1996

CAFE(기업평균연비) 규제의 적극적 대응책의 하나로 차체 경량화가 주목받고 있다. 이를 위해 사용되는 고분자 복합소재 중 특히 Exterior Body Panel에 많이 채택되고 있는 SMC(Sheet Molding Compound)에 대해 제조방법, 성형공정, 기술적 과제, 재활용, 적용 예 등을 살펴보았다. 1973년 GM의 Corvette로부터 본격적으로 사용되기 시작한 SMC는 미국, 유럽을 중심으로 사용량이 계속 증가되고 있으며, 자동화가 용이하고 성형Cycle이 짧아 타 열경화성 고분자복합재료 성형방법에 비해 대량생산에 유리하며, 도장 특성이 우수하며 자 동차 부품용으로 가장 보편적인 방식이다.

• Proceedings of the Korean Institute of Industrial Safety Conference
• /
• 2003.10a
• /
• pp.176-179
• /
• 2003

범용 엔지니어링 플라스틱(Engineering plastic)인 PET(Polyethylene terephthalate)수지는 투명성, 강도특성, 내열특성, 기체차단성 등 물성이 우수하여 합성섬유, 이축연신 film, 식음료용 bottle 등의 용도로 널리 사용되는 적용범위가 매우 넓은 고분자 소재이다. 그러나 폐기된 PET 수지를 물질재활용(material recycling) 방법으로 재가공할 경우 수지 자체가 갖는 가수분해(hydrolysis)와 열분해(thermal degradation) 특성으로 인해 가공성 및 기계적 특성이 현저히 저하되는 단점이 있다.(중략)

• Proceedings of the Korean Environmental Sciences Society Conference
• /
• 2008.11a
• /
• pp.571-574
• /
• 2008

계량 습식방법으로 실험한 결과 다른 처리 방법과는 달리, 물리성과 환경성 모든 항목에서 적합함을 나타내었다. 그러므로 원예농업용 폐비닐의 저급물리성과 중금속등의 유해 물질 검출의 우려로 인한 사용기피를 조금이나마 불식하고 기존에 유해성분 검출로 토양이나 작물에 문제가 됐던 원예농업용 자재를 대체할 수 있는 자재로서의 가능성을 보였다고 할 수 있다.

• The monthly packaging world
• /
• s.208
• /
• pp.52-55
• /
• 2010

골판지 포장산업은 내수산업 특성을 지닌 주문생산 산업으로 과당경쟁이 심한 저부가가치 산업으로 부피가 커 수요지 중심 분산분포형의 전형적인 중소기업형 산업이다. 특히 골판지 포장산업은 폐지를 95% 이상 재활용하는 대표적인 친환경 소재산업이며 국내 종이 생산 최다지종(35%)으로 대표적 제지분야이다. 본 고에서는 한국골판지포장공업협동조합이 올해 발표한 자료를 토대로 국내 경기 전망을 살펴보고 골판지 포장생산 현황과 시장동향 등에 대해 살펴보도록 한다.