• 전기학회논문지
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• 제56권2호
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• pp.338-342
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• 2007

The increase of activated carbon contents in fly ashes accelerate the corrosion of steel embedded in ordinary portland cement(OPC) mortar. Cement losses its identity of colour when the % of carbon is increased. More than 60[%] area was rusted when carbon content is increased beyond 8[%] for the exposure period of one year. Comparable corrosion rate with OPC was obtained up to 6[%] carbon level only. The tolerable limit of replacement for various admixed carbon system under aggressive alternate wetting and drying condition with 3[%] NaCl was found to be 6 to 8[%].

• 한국세라믹학회지
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• 제39권12호
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• pp.1164-1170
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• 2002

고령토질 벽돌에 대한 fly ash의 첨가가 소결온도에 미치는 영향과 그에 따른 물성의 변화를 관찰하였다. Fly ash로는 탄소 8∼9%의 무연탄 연로 재를 사용하였고 고령토 등의 국산 천연원료를 이용하여 실험을 하였다. Fly ash와 고령토 등의 4종의 원료를 5가지의 혼합비로 조합하여 혼합, 성형하고 각각 1050${\circ}C$, 1100${\circ}C$, 1150${\circ}C$, 1200${\circ}C$의 온도로 소성하였다. 소성온도가 증가함에 따라 모든 시편에서 흡수율은 낮아지고 압축 강도는 증가하였다. 소성온도가 1100${\circ}C$ 이하인 경우 fly ash의 함량이 증가함에 따라 흡수율은 증가하고 강도가 감소하였다. 이에 비하여 소성온도가 1150${\circ}C$ 이상인 경우 흡수율은 소성온도가 낮은 경우와 유사한 경향을 보였으나 강도는 증가하였다.

• 자원환경지질
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• 제28권2호
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• pp.147-154
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• 1995

Coal fly ashes collected from the Samcheonpo and the Seocheon Power Plants were analyzed for major and minor components and heavy metals such as As, Cd, Co, Cr, Cu, Ga, Hg, Mo, Ni, Pb, Sb, V and Zn in order to suggest basic data to apply coal fly ash as fertilizer or soil ameliorator. The specific gravity of the samples was less than 2.0, and amounts of organic matter range from 5.0% to 12.3%. The identified minerals by XRD were mainly quartz, mullite and pyrite in anthracite coal, and mainly quartz and mullite in bituminous coal. Generally, the contents of heavy metal elements analyzed were lower less than those of soil, though higher in some samples. Element couples of some elements( e.g., As-Mo, Zn ; Mo-As, Sb, V, Zn ; Sb-Zn ) show positive correlations with each other, but the high correlations of toxic elements such as As, Pb, Cd and Hg indicate to give attention to apply coal fly ash as fertilizer or soil ameliorator.

• 자원리싸이클링
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• 제10권5호
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• pp.36-43
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• 2001

The chlorine component in fly ash from municipal solid waste incineration ash was removed by water washing for the purpose of recycling fly ash as a raw material of ordinary portland cement. The samples were a different kind of 리y ashes using $Ca(OH)_2$and NaOH as media of wet scrubber for flue gas cleaning. The content of soluble salts of fly ash using $Ca(OH)_2$and NaOH was 32.8%, 50.1% and the content of chlorine component, 22.9% and 26.0% respectively, which was KCl, NaCl, CaC1OH mainly. When each fly ash was washed using water under conditions of a agitation speed of 300 rpm, a liquid to solid ratio of 10, most soluble salts in fly ash were dissolved within 30 minutes and the content of chlorine component in ash was diminished to the content of 4.4%, 2.O% at $20^{\circ}C$ and 1.7%, 0.8% at $50^{\circ}C$ respectively. And the main compound of residual chlorine component in ash after water washing was friedel`s salt ($3CaO.A1_2$$O_3$.$CaCl_2$.$10H2$O). From analysis results of water quality for wastewater by water washing, the components exceeding discharged wastewater standard were only Pb and Cd. But As pH was controlled to 10 with addition of $CO_2$(g) or $Na_2$$_CO3$in water, the concentration of heavy metals such as Pb and Cd was also under discharged wastewater standard.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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• pp.593-598
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• 2002

Recently, as industrialization is rapidly growing and the standard of life is rising, the quantities of waste glasses have been hastily increased and most of them are not recycled but abandoned. It causes some problems such as the waste of natural resources and environmental pollution. Therefore, in this study freeze-thaw resistance test was conducted to analyze the properties of concrete containing waste glasses as fine aggregates and containing industrial by-products (fly ashes, silica fumes). As a results, it was found that freeze-thaw resistance decreases as the content of waste glasses increases. Also, the content of fly ash doesn't affect to the freeze-thaw resistance, and freeze-thaw resistance decreases with tile increase of silica fume contents.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.296-300
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• 2001

In order to recycle the incineration ash (bottom ash and fly ash) generated from the incineration of municipal waste for a cement material, salts as well as heavy metal should be removed by the stabilization treatment. Most of these heavy metal and over 80% of salts are removed by a washing as a pre-treatment. However, wastewater which is another pollutant is generated by a washing, then proper treatment should be developed. First the characteristics of incineration ashes collected from two domestic full-sized incinerators were investigated and removal rate of salts and heavy metals from them also studied. The wastewater quality was compared to the criteria of the regulation by analyzing the characteristics of generated wastewater during the washing of incineration ash as a condition of liquid/solid ratio. Also, we tried to used this experimental results for the basic data to develop proper processing technique of municipal waste.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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• pp.1416-1417
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• 2006

The increase of carbon contents in fly ashes accelerate the corrosion of steel embedded in ordinary portland cement mortar. Cement losses its identity of colour, when the % of carbon is increased. More than 60[%] area was rusted, when carbon content is increased beyond 8[%] for the exposure period of one year. Comparable corrosion rate with OPC was obtained up to 6[%] carbon level only. The tolerable limit of replacement for various admixed carbon system under aggressive alternate wetting and drying condition with 3[%] NaCl was found to be 6 to 8[%].

• 환경위생공학
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• 제16권2호
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• pp.63-70
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• 2001

This study was initiated to evaluate and resolve the potential problems caused as the MSWI(Municipal Solid Waste Incinerator) fly ash were stabilized and solidified into the cement. The physical and chemical properties of fly ashes (K and M) used in this study were fixed according to the operating conditions of the incineration plant. The compressible strength of the solidified matrix used in this study were measured at 7, 28, and 56 curing days, respectively, to evaluate the stability of the solidified matrix, which were further analyzed by XRD and SEM. The experimental results obtained in this study showed that the relatively long hours of curing periods were needed to solidify the fly ash. The solidified matrix containing K ash had the high and excellent compressible strength of $200{\;}kg/\textrm{cm}^2$, after 56 curing days, but was not good enough in appearance. The analytical data by SEM confirmed that the alkaline Na and K, which are highly dissolved in water, were included in the fly ash and evenly distributed into the exterior surface of the solidified matrix. Whereas, the solidified matrix containing M ash never showed such a compressible strength as shown in the K ash due to the severe fracture, even as early as 7 curing days. Based on its XRD analysis, it appeared that both $C_2S$ and $C_3S$ highly related to the compressible strength were not crystallyzed into the solidified matrix. However, the compressible strength of the solidified and cemented M ash was remarkably improved by 100 times, after the alkalinity was washed out, which indicated that it is equivalent to 30 to 40g per one kg of fly ash.

• 한국결정성장학회지
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• 제8권3호
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• pp.513-517
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• 1998

석탄회의 점노를 70:30의 비율로 혼합하여 마이크로파를 이용하여 소결하였으며, 소결에는 2.45Ghz의 일반가정용 마이크로파 오븐을 사용하였다. 시편은 $1,150^{\circ}C$에서 50분까지 10분 간격으로 소결하였다. 석탄회의 미세구조는 주사전자현미경(SEM)과 Energy dispersive spectrometry(EDS)를 이용하여 분석을 하였으며 X선회절 분석과 압축강도와 겉보기 비중을 추정하여 비교하였으며 시간이 지날수록 시편의 기공크기는 작아졌으나 압축강도와 겉보기 비중은 변화의 크기가 작았다. 로안에서의 마이크로파에 의한 시편으로의 열전달현상을 알아보기 위하여 컴퓨터를 이용한 수치해석을 행하였다.

• 자원환경지질
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• 제31권6호
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• pp.509-518
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• 1998

Fly ashes have been deposited around Youngwol power plant until electrostatic precipitator was installed in 1981. Fresh fly ash samples from electrostatic precipitator and weathered fly ash from ash disposal site were collected from Youngwol power plant, along with 65 soil samples of nearby area to look into the influence of PFA deposit on the soils in surrounding area. In chemistry, EPA does not contain high level of toxic elements and there is no notable concentration of toxic elements in soil near power plant. Total concentrations of Co, Cr, Cu, V, and Zn are 13 ppm, 89 ppm, 73 ppm, 157 ppm and 57 ppm in PFA. Concentrations of theses elements in ash-rich soils are 15 ppm, 78 ppm, 60 ppm, 133 ppm and 68 ppm, and those in ash-poor soils are 19 ppm, 70 ppm, 38 ppm, 91 ppm and 97 ppm. But these metal elements are highly concentrated in magnetic fractions of EPA (Co, 129 ppm; Cr, 217 ppm; Cu, 210 ppm; V, 197 ppm; Zn 90 ppm). Considering the process of long-term weathering of PFA, potentially toxic substances from the ash could be leached into soils and groundwater.