• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1999년도 봄 학술발표회 논문집
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• pp.513-520
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• 1999

20 million tons of coal ash has been produced in Korea annually. This causes the environmental problems and the cost of land for ash pond. However the amount of coal ash for recycling is small because of the low level of recycling technology and the ignorance. As the coal ash has the significant engineering properties, it can be utilized as soft ground stabilizer, backfill materials and so forth. The purpose of this paper is to summarize some of the recycling methods of coal ash. One is structural backfill materials, the other is flowable fill. Optimal mixture ratio(fly ash : bottom ash) is determined for structural backfill materials and the model test is performed. The model test accompanied with physical tests were executed for identifying that the flowable fly ash can be used as fill materials such as trench back filling.

• 한국건축시공학회지
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• 제17권2호
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• pp.183-189
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• 2017

플라이애시는 시멘트 계열 재료의 혼화재료로서 널리 사용되고 있는 재료이다. 다만, 플라이애시는 화력발전소의 석탄재를 포집하여 정제과정을 거친 재료로서 정제과정의 에너지 소모 및 유통과정에서의 품질 확보가 중요하다. 이에 본 연구에서는 플라이애시 생산과정 중 발생하는 세 가지 종류의 다른 품질의 석탄재를 대상으로 각각의 입자조건과 시멘트 페이스트 상태에서 레올로지 거동을 평가하였다. 실험결과 리젝트 애시는 작은 석탄재 입자가 응집되어 굳어진 다공질의 큰 입자로 구성되어 있었고, 그러한 이유로 시멘트 페이스트에 포함될 경우 공기량이 높게 측정되는 경향이 나타났다. 유동성 측면에서는 석탄재가 치환되는 경우 유동성이 증진되는 양상을 보였으며 특히 점도 측면에서는 입자조건에 따라 점도를 조정할 수도 있었다.

• Advances in concrete construction
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• 제4권4호
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• pp.231-242
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• 2016

The major problem of a coal combustion-based power plant is that it creates large quantity of solid wastes. So, to achieve the gainful use of waste materials and to avoid other environmental problems, this study was undertaken. The quantity of coal ash by-products, particularly coal fly ash and coal bottom ash has been increasing from the coal power plants around the world. The other objective of this study was to explore the possibility of utilization of coal ash in the production of ash bricks. In 15 different mixes, Mix Designation M-1 to M-15, the varying percentages of lime and gypsum were used and sand was replaced with coal bottom ash. Further, it has been noticed that the water absorption and compressive strength of mix M-15 is 13.36% and 7.85 MPa which is better than the conventional bricks. The test results of this investigation show that the prism strength of coal ash masonry prisms was more than that of the conventional bricks.

• 자원리싸이클링
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• 제5권3호
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• pp.44-49
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• 1996

국내 석탄발전소에서 배출되고 있는 비산회의 재활용에 가장 큰 문제점은 비산화에 혼입되어 있는 미연탄소분이다. 본 연구는 기존 포말부유선광법으로 유연탄비산회의 미연탄소분을 제거할 때 기포제종류 및 첨가량의 영향, 포집제 첨가량의 영향을 실험하고, 여기에서 수율, 회수율, 미연분제거율, 공정효율을 구하였다. 또한 비산회정제 전후의 화학적 성분을 분석하여 성분변화를 확인하였다. 실험결과는 유연탄 비산회 중의 미연탄소분을 92.4%까지 제거할 수 있었으며, 그 결과 비산회의 순도를 99.4%까지 높일 수 있었다.

• 한국연초학회지
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• 제19권2호
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• pp.92-101
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• 1997

This study was conducted to investigate the effect of fly ash on the yield and quality and to determine the optimum application amount of fly ash for tobacco(Nicotiana tabacum L). Two kinds of fly ash, anthracite and bituminous coal, were treated with different levels of 0, 20, 40, 60 MT/ha. Dry weights of tobacco at middle and topping growth stage were increased with application of fly ash, showing the highest dry weight at 40 MT/ha in both kinds of fly ash. It was showed that the bituminous coal had a little more effective for yield than that of anthracite. Comparing with the control, yields of tobacco applied with fly ash were significantly increased about 17.7% and 17.1% by the application of bituminous coal and anthracite, respectively. Quality of flue-cured leaves was better by application of fly ash than that of the control. The quality index was given the highest at 40 MT/ha for bituminous coal increasing by 24.6% and at 60 MT/ha fur anthracite increasing by 13.4% compared with the control. The economical efficiency considered of the yield and quality of tobacco was the highest at 40 MT/ha of bituminous. Soil pH, contents of available P2O5, organic matter, exchangeable Ca2+ and Mg2+ of soil during the growing season were increased by application of fly ash, showing more effectiveness in bituminous than that in anthracite. By the application of fly ash, the nutrients availability and the acidity of soil were reformed and they caused significantly the increase of growths yield, and quality of tobacco. By the application of lime reforming soil acidity, growth response, yields and quality of tobacco were not increased compared to the control, although the effect of reforming soil pH was remarkable.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.616-620
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• 2001

The objectives of this study are to investigate the suitability of various coal fly ashes and incineration ashes for zeolite synthesis. Zeolite P and hydroxysodalite are produced from coal fly ash and paper sludge incineration ash. When soluble and acid-soluble materials in incineration fly ash are removed by the water washing or acid washing before hydrothermal synthesis, hydroxysodalite can be produced. The factors to make solid-liquid separation difficult are the calcium component and the unburned carbon in ash.

• 한국결정성장학회지
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• 제3권2호
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• pp.185-201
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• 1993

본 연구의 목적은 석탄회의 물리.화학적 및 미세구조적 특성들을 규명하여 석탄회의 산업화를 증가시키는 것이다. 실험에 의하면 석탄회의 3주성분들은 $SiO_2$, $Al_2O_3$ 및 C이며 quartz와 mullite의 결정상을 함유하고 있다. 석탄회는 미세구조적 형태에 따라서 7가지로 선별되며, cenosphere는 floater와 건식분리된 cenosphere들로 구분되며 $SiO_2$와 $Al_2O_3$ 로 구성되어 있다. Cenosphere 응집은 고온과 고압의 조건하에서 작은 입경의 cenosphere들이 흡착과 neck growth에 의해 형성된다.

• 한국건축시공학회지
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• 제21권2호
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• pp.141-148
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• 2021

본 연구에서는 산업부산물 중 순환유동층 연소방식과 미분탄 연소과정에서 발생되는 플라이애시와 고로슬래그 미분말을 치환한 시멘트 모르타르의 특성을 파악하였다. 연구 결과, 순환유동층 플라이애시 및 미분탄 플라이애시 혼합 사용 시 강도발현 뿐만 아니라 내구성 측면에서도 유리하게 나타난다. 순환유동층 플라이애시는 초기 반응성 향상에 기여하며, 미분탄 플라이애시는 포졸란 반응으로 장기 강도 발현에 관여하게 된다. 따라서 순환유동층 플라이애시와 미분탄 플라이애시의 혼합사용은 고로슬래그 미분말을 치환한 시멘트 모르타르의 상호 보완적인 요소로 작용함을 알 수 있다.

• Architectural research
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• 제4권1호
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• pp.39-44
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• 2002

Recently, the coal-ash production has been increased by increase of consumption of electric power. So it is important to secure a reclaimed land from pollution and develop practical application of coal ash. This is an experimental study to compare and analyze the properties of concrete using high volume of coal ash (including fly ash and bottom ash) as a part of fine aggregate. For this purpose, the mix proportions of concrete according to replacement ratio of coal ash (10, 20, 35, 50%) were selected. And then air content, slump, setting time, bleeding content, chloride content, compressive strength and carbonation test were performed. According to test results, it was found that the bleeding content of concrete using the coal ash decreased according to increase of replacement ratio. And the chloride content of concrete using the bottom ash as a part of fine aggregate increased as the replacement ratio of bottom ash increased, but it is satisfied with the total chloride content of concrete recommended by KCI - $0.3kg/m^3$ below. Also, the compressive strength of concrete using the bottom ash was similar to that of plain concrete(BA 0) after 28days of curing and the carbonation depth of concrete increased as the replacement ratio increased. However, the carbonation depth of concrete using the fly ash decreased as the replacement ratio of fly ash increased.

• 한국세라믹학회지
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• 제33권7호
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• pp.771-778
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• 1996

Utilization of fly ash by-produced from coal fired power plants and classified as general waste became very important problem to solve in the environmental protection and recycling of waste materials. The possibility of large scale substitution of fly ash as a raw material for bricks and wet tiles was highly expected because the chemical compositions of fly ash were mostly Al2O3 and SiO2 and the properties of it were very similar with clay. Accordingly in order to investigate the substitutional limit these specimens were substituted from 0 to 100 wt% fly ash by 20wt% increment for clay. Fly ash-clay bodies were fired at 1200, 1250 and 130$0^{\circ}C$ and then their properties were measured, It was found that these specimens sintered at 125$0^{\circ}C$ had a good bending strength. Especially when these sintered bodies were added to 20, 40 and 60 wt% fly ash the bending strength of those were 201 , 205 and 191kg.cm2 respectively with the water absorption below 1%, This showed that fly ash could be substituted ab 60 wt% in this experiment.