• Environmental engineer
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• s.158
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• pp.34-39
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• 1999

• Environmental engineer
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• s.161
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• pp.40-45
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• 2000

• Resources Recycling
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• v.6 no.3
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• pp.15-21
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• 1997

Flyash from a coal-hed power plan1 is produced approximtcly 3 million tons m 1996 and causes the serious environmentalpmblem due to the disposal in the ash pond. Flyash is an accepted additive in concrete where it adds strength, sulfate ateresistanceand reduced cost, provided acccptablc levcls of unbunrned carbon are mmtmed This papzr describes to investigate thc technicalfeasibility of a dry triboelcctrostatlcp roccss to scparate unburned carbon h m f lyash into economically valuable produck Puliclesof unburned carbon and flyash can be impded positivc and negative surface charzes. rcapeclively. with a copper tniochargcr dueto dirferences in the work function values of thc particles and the tnbacharger. and cm he separated by passing thcm throuph anexternal electic field. A laboratory s d e separation system consists of r sacw feeder for ash supply, a tniocharger, verticalcollecling copper plates, power supplies, a flow meter, and a fan. Separation tests taking into account separahian efficiency and ashrecovery showed that flyash recovery was sh-nngly dependent an thc tnbocharger geomzhy, elect"c ficld strength. flyssh s ~ c a,n dash feeding late. Optimal separation conditions were flyash size less than 125 Fm and electric field shcngrh of 200 kV1m. Ovcr 80%of the flyash with 7% lass on ignition was recovered at wrbon contznts less than 3%bon contznts less than 3%

• Proceedings of the KSEEG Conference
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• 2000.04a
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• pp.27-29
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• 2000

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1999.04a
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• pp.223-224
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• 1999

• Proceedings of the Materials Research Society of Korea Conference
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• 1999.05a
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• pp.147-147
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• 1999

• Journal of Energy Engineering
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• v.25 no.4
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• pp.53-61
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• 2016

Unburned Carbon(UBC) and NOx emissions from High-moisture coal and Dried coal were investigated in Drop Tube Furnace(DTF). When the same amount of the High-moisture coal and Dried coal were oxidized in DTF, the results show that UBC and NOx emissions of Dried coal case is higher than High-moisture coal case. As the moisture in coal decreases from 40% to 10%, the average gas temperature increases but the moisture concentration in DTF decreases. As the wall temperature increases from $900^{\circ}C$ to $1500^{\circ}C$, the UBC decreases and NOx emissions increases. Especially, the difference for UBC between High-moisture coal and Dried coal decreases with increasing wall temperature.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.669-672
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• 2008

bottom ash has difficult in recycling because of low activity and unburned carbon. so our study was control the unburned carbon for improvement of bottom ash. unburned carbon was controlled by distribution. The result of distribution is good that unburned carbon of bottom ash decrease in 4.5%. when we are replace bottom ash with OPC to 10$\sim$30%, specimens strength is decrease. but mix of controlled bottom ash revealed that it's strength increase 6% better than uncontrolled bottom ash.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.12
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• pp.963-969
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• 2014

Four coal sources that had different ash contents were evaluated in a drop tube furnace (DTF). Combustion experiments were conducted by using several sources with different particle sizes and excess air ratios under air-staging conditions to determine the optimized combustion conditions of high-ash coal, with an emphasis on the combustion efficiency and NOx emissions. The results show that the higher ash content results in a large amount of carbon remaining unburned, and that this effect is dominant when the largest particle size is used. Furthermore, the ash content of coal does affect the Char-NOx concentration, which decreases with the particle size. The results of this study suggest that an air-staged system can be useful to reduce the NOx emissions of high-ash coal and that control of the air stoichiometric ratio of the primary combustion zone (SR1) is effective for reducing NOx emissions, especially by considering unburned carbon contents.

• 한국연소학회:학술대회논문집
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• 2015.12a
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• pp.99-102
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• 2015

To operate coal fired power plant efficiently is considered unburned carbon as important factor. But, unburned carbon contents change does not have an impact on Boiler performance simultaneously. we evaluated that unburned carbon contents change had an little influence on unburned carbon loss change for performance side at a real power plant.