• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.259-260
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• 2018

This study evaluated the compressive strength, freeze-thaw and sulfate resistance characteristics of concrete using CFBC-Ash. The CFBC-Ash was adjusted to a particle size of 75 ㎛ or less and using by increasing the fineness of powder through milling. As a result, it was confirmed that the concrete using CFBC-Ash shows a high compressive strength, durability. Also, it is confirmed that CFBC-ash can be used as a concrete binder.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05b
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• pp.781-786
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• 1995

석탄화력발전소 산업부산물인 Fly ash를 이용한 고준위방사성폐기물의 붕규산 유리고화 가능성을 분석하였다. Fly ash SiO$_2$, NaNO$_3$, B$_2$O$_3$에 DUPIC 핵연료 제조공정으로부터 발생되는 모의 scrap waste를 20 wt% 혼합하여, l15$0^{\circ}C$ 에서 3시간 용융시켜 붕규산유리화시켰다. 또한 붕규산유리고화체의 침출성을 평가하기 위하여 2일동안의 soxhlet 침출실험결과 양호한 내침출성을 보였다. 또한 고체폐기물의 안정화물질로 fly ash를 사용할 경우 fly ash 함량을 57%까지 첨가하여도 붕규산유리고화체의 제조가 가능함을 확인하였으며, fly ash의 첨가로 인한 유리화원료 재료비를 30% 까지는 절감시킬 수 있을 것으로 예상된다.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.11a
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• pp.225-226
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• 2017

Recently, there has been a growing interest in the development of non-sintered binder to reduce CO2 emissions from the cement clinker manufacturing process and a number of studies have been conducted on fly ashes as an industrial by-product. However, in order to utilize fly ashes as a non-sintered binder, it is necessary to solve problems such as safety issues and economical efficiency due to use of an alkali activator. This study evaluates the material properties and compressive strength characteristics of three types of circulating fluidized bed boiler ashes. As a result, it was confirmed that the characteristics of each binder vary depending on the location of the power plant and the types of raw materials. In addition, it has been confirmed that the fluidized bed boiler ash shows a high compressive strength and can be used sufficiently as an non-sintered binder.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.272-275
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• 2017

최근 국내 대부분의 원자력 발전소 2차 계통 중 복수 탈염설비의 운전 시 pH를 제어하기 위해 에탄올아민(Ethanolamine, ETA)를 사용하고 있으나 ETA를 적용한 후 발생하는 폐수에 의한 방류수의 화학적 산소요구량(COD) 및 총 질소(TN)의 증가는 심각한 환경적인 문제를 발생 시킨다. ETA가 강이나 하천과 같은 수계로 유입되면 자연적으로 생분해되기 힘들고, 분해부산물이 증가되어 수질을 악화시킬 수도 있다. 이러한 문제점을 해결하기 위해 본 연구에서는 폐경석, 제강슬래그, 저회를 혼합하여 제올라이트화(zeolitization)과정을 통해 새로운 형태의 저비용, 고효율의 ETA 처리용 복합흡착제를 제조하였다. 최적의 흡착 및 이온교환능력을 갖는 복합흡착제는 폐경석, 제강슬래그 및 저회의 혼합조성비를 Mixture Analysis 통계법을 통해 도출하였다.

• Resources Recycling
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• v.23 no.2
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• pp.81-89
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• 2014

Approximately 8.5 million tons of fly ash and 740,000 tons of briquette ash were produced in 2010. Inefficient recycling of coal ash has been a heavy economic and environmental burden and economical coal ash utilization technologies are required to turn coal ash into valuable resources. In this study the patents and literature were analyzed to understand the present situation of coal ash recycling technologies and to promote utilization of coal ash for producing a non-sintering green cement, geopolymer. The survey was based on the open patents of USA, European Union, Japan and Korea, and the papers in SCI - indexed journals published between 1979 and 2013. Technical key words were used for data collection and noise filtering. Trends of recycling technologies in utilization of coal ash for producing geopolymers were discussed in terms of time periods, countries, companies and various forms of technologies.

• Journal of Energy Engineering
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• v.21 no.1
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• pp.68-74
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• 2012

Sub-bituminous coals have been used increasingly in coal-fired power plants with a proportion of over 50% in the blend with bituminous coals. As a result, the unburned material in fly ash has increased and is causing problems in utilizing the fly ash as an additive for concrete production. In this study, analysis of fly ash obtained from a 500 MWe power plant was carried out and unburned material in the fly ash found to be soot. The coals used in the plant were analyzed with CPD model to investigate the sooting potential depending on the coal type and blending ratio.

• Resources Recycling
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• v.26 no.2
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• pp.71-79
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• 2017

Circulating fluidized bed combustion (CFBC) ash is one of useful mineralogical resources having abundant content of free lime and anhydrite, and has a self-cementitious property. Recently, considerable interest has been gained regarding the utilization of CFBC ash, along with its use in mine backfill and reclamation. Prior to adopt the use of CFBC ash in the mine backfill technology, discussion on the technology and related specification is prerequisite in the future. This paper presents a review on studies in the emerging technology of CFBC ash utilization, and provides useful information with regard to the specifications for mine backfills utilizing CFBC ash.

• Analytical Science and Technology
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• v.15 no.6
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• pp.567-573
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• 2002

The most important and largest commercial outlet of fly ash in Korea is a replacement material of Portland cement in concrete industry. The high level of unburned carbon in ash brings about some malfunctions in concrete. Therefore, fly ash is refined to improve the quality as a concrete additive. In this process, a lot of the residual carbon is produced, and discarded now. In the present study, to find out a valuable outlet of the enriched carbon samples, the basic morphology of residual carbon in fly ash from Boryung power plant was investigated. The unburned carbon characterization included shape, size measurement, and chemical analysis was examined using scanning electron microscope (SEM) and energy dispersive X-ray spectrometer (EDX).

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.423-431
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• 2022

Due to increase of interest in 'carbon neutrality', attempts at agricultural use of CO₂ are increasing. In this study, we used the dry-ice made by CO₂ as by-product in thermoelectric power plant on CO₂ fertilization for production of leafy vegetable in greenhouses. The dry-ice was supplied on three leafy vegetable farms (Allium tuberosum Rottl. ex Spreng, Aster scaber, and Oenanthe stolonifera DC.) located in Hadong, Gyeongsangnamdo. Two greenhouses were used in each leaf vegetable crops, one greenhouse used as the control (non-treatment), other greenhouse used as supplied CO₂. For CO₂ fertilization, a gas sublimated from dry ice was supplied to the greenhouse using a specially designed prototype supply machine. A. tuberosum greenhouse has no difference of CO₂ concentration between the control, and CO₂ fertilization and shown high CO₂ concentration both greenhouses. However, the CO₂ concentrations in A. scaber and O. stolonifera greenhouses were increased in CO₂ fertilization treatment. The growth of A. scaber and O. stolonifera were increased in CO₂ fertilization, and the yield also increased to 36% and 25% than the control, respectively. As a result of economic analysis, the A. scaber has increase of income rate, however A. tuberosum and O. stolonifera has decreased income rate. Thus, the use of the dry-ice made by CO₂ as by-product in thermoelectric power plant has possibility to increase productivity of the leafy vegetable in greenhouse and have agricultural use value.

• Journal of the Korea Institute of Building Construction
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• v.23 no.6
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• pp.663-671
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• 2023

This research experimentally evaluated the recyclability of four varieties of lignocellulosic fly ash(FA), a by-product from three power plants employing lignocellulosic biomass(Bio-SRF, wood pellets) as a fuel source. Comprehensive analyses were conducted on FA, encompassing both physical parameters (particle shape, size distribution, fineness, and density) and chemical properties(chemical composition and heavy metal content). Mortar test specimens, with FA mixing ratios ranging from 5 to 20%, were produced in compliance with KS L 5405 standards, and their flow and compressive strength were subsequently measured. The test results indicated that the four types of FA exhibited particle sizes approximately between 20~30㎛, densities around 2.3~2.5g/cm³, and a fineness range of 2,600~4,900cm²/g. The FA comprised approximately 50~90% of components such as SiO₂, Al₂O₃, Fe₂O₃, and CaO, displaying characteristics akin to type-II and type-III FA of KS L 5405 standards, albeit with differences in chlorine and SiO₂ content. From the mortar tests, it was observed that the compressive strength of the mortar ranged between 34~47MPa when the pellet combustion FA was mixed in proportions of 5~20%. FA, produced exclusively from the combustion of 100% lignocellulosic fuel, is assessed to possess high recyclability potential as a substitute for conventional admixtures.