• Journal of the Korean Recycled Construction Resources Institute
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• v.12 no.1
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• pp.53-62
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• 2024

In this paper, an experimental study on the strengths and material properties of concrete manufactured by using coal gangue, as a fine aggregate was conducted. Experimental parameters included coal gangue aggregate contents as a replacement of fine aggregate by 50 % and 100 % (by volume) and fly ash contents. The water-binder ratio was fixed at 0.38. In addition, 30 % of the OPC binder was replaced with fly ash in some mixtures. Test of the unit weight, compressive, split tensile, and flexural tensile strength of concrete were performed and test results were analyzed. Unit weight, compressive strength, split tensile strength, and flexural tensile strength decreased as the coal recycled aggregates increased. In addition, TGA and SEM experiments, which are microstructure experiments, were conducted to analyze thermogravimetric analysis and ITZ by section.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.365-366
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• 2001

전기를 만들 후 인류는 많은 발전을 하였고, 전기는 인류에 있어서 불가분의 한 부분이 되었다. 또한 계속적인 전기사용의 증가로 인해 발전소가 늘고 있으나, 그 부산물인 산업폐기물에 대한 처리가 다른 문제점으로 대두되고 있다. 정부의 정원계획에 따르면 전기사용량은 최근 10년간 연평균 10％ 증가하였고, 총 발전량의 35％를 석탄화력발전에 두고 있다. 석탄은 화력이 좋다는 장점외에 부산물로서 재를 남기는 단점을 가지고 있다. (중략)

• Journal of Korean Society of Environmental Engineers
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• v.30 no.11
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• pp.1075-1086
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• 2008

In order to investigate the applicability and suitability of the industrial by-products to apply mono-layer cover system for non-sanitary landfill sites, 6 different industrial by-products, such as construction waste, bottom ash, gypsum, blast furnace and steel manufacture slags, and stone powder sludge, were evaluated. Various physicochemical and hydrodynamic properties of the industrial byproducts were investigated. The environmental safety was monitored using batch and long-term leaching tests as well. In addition, the flexibility of plants was observed by cultivating them in the industrial by-products. The results for physicochemical properties indicate that most of the materials considered appeared to be suitable for landfill cover. Particularly, the concentration levels of hazardous elements regulated by the Korean Law for Waste Management did not exceed the regulatory limits in all target materials. In addition, the concentrations of regulated elements for the Korean Soil Conservation Law were examined below the regulatory limits in most of materials considered, except for the stone powder sludge. The results of batch and long-term experiments showed bottom ash and construction waste were the most suitable materials for landfill cover among the industrial by-products considered. The results of plant studies indicate that the bottom ash among industrial by-products considered was most effective in developing vegetation on landfill site, showing fast germination and large growth index. At the final covering system made of mixture of soil and bottom ash, the optimum application rate of farmyard manure was observed to be 40-50 Mg/ha.

• Applied Chemistry for Engineering
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• v.22 no.3
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• pp.296-300
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• 2011

In this work, various wood biomasses were used to determine the combustion characteristics for the fuel of cogeneration plant. Combustion characteristics of four types, i.e., (i) forest products, (ii) recycled wood, (iii) empty fruit bunch, and (iv) palm kernel shell, were examined via thermal gravimetric analyzer (TGA) in air atmosphere and coal was used as a comparison group. From the TGA results, the combustion of the wood biomass was occurred in the range of 280 to $420^{\circ}C$, which was lower than that of coal. Forest product showed the lowest activation energy (0.4 kJ/mol) compared to that of other wood biomasses (about 6 to 14 kJ/mol) and coal (64 kJ/mol). In addition, the reaction rate constant of the wood biomass was lower than that of coal. These results indicate the higher combustion initiation rate of wood biomass due to the high content of volatile matter, which had a low boiling point.

• 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.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1999.05a
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• pp.85-88
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• 1999

석탄가스화 복합발전(IGCC, Integrated Gasification Combined Cycle)은 고효율, 청정 전력 생산 기술로 차세대 석탄이용 발전 기술의 대안으로 제시되고 있다. 기존 석탄화력발전소의 발전 효율인 36-38%보다 적어도 2-6% 우수한 효율을 나타내고 있으며 21세기 석탄 이용시 적용될 환경 규제치를 가장 현실적으로 만족시킬 수 있는 차세대 석탄화력발전 시스템으로 평가받고 있다. 고청정 환경성의 측면에서 석탄가스화 복합발전설비는 기존의 유연탄 화력발전 방식에 비해서 SOx, NOx 및 분진 등의 배출량을 크게 감소시킬 수 있을 뿐만 아니라 재(ash)를 분진형태가 아닌 용융된 후 엉긴 슬랙형태로 수거하므로 환경적으로 안전하며, 슬랙과 탈황공정에서 만들어지는 황원소를 회수하여 경제성 있는 부산물로 활용할 수 있다는 장점이 있다.(중략)

• Geotechnical Engineering
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• v.11 no.2
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• pp.37-50
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• 1995

Recently, the treatment of coal ashes produced from thermal electric power plants have been raised as a serious problem in according to the increasing of electric power demand in Korea. This paper deals with a re -use method of coal ash as a fill material. Two domestic coal ashes are mixed with cement and lime to improve the mechanical properties of coal ash. The mechanical properties such as compressive strength, compressive deformation, permeability and frost heaving property are investigated in according to the change of admixture rate, curing temperature and curing time. In this study, it is found coal ash (fly ash+bottom ash) and fly ash with 2%~3% cement can be used as a fill material, respectively. It is also found the frost heaving properties of coal ash is effectively improved by the mixture of 6%~9% cement.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.05b
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• pp.319-323
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• 1997

석탄화력발전소의 부산물인 석탄회를 이용한 DUPIC dirty scrap waste의 유리고화체에 대한 내침출성을 분석하였다. Fly ash, SiO$_2$, NaNO$_3$, B$_2$O$_3$에 DUPIC 핵연료 제조공정으로부터 발생되는 모의 dirty scrap waste를 15 wt% ~ 30 wt% 혼합하여, 115$0^{\circ}C$ 에서 3시간 용융시킨 후 서서히 냉각시켜 얻은 유리고화체의 침출성을 온도, 침출액의 종류, 폐기물의 함량 등에 따라 평가하였다 침출실험결과 석탄회유리고화체는 양호한 내침출성을 보였다. 석탄회유리고화체의 침출율은 합성지하수, 합성해수, 증류수의 순으로 감소하였으며, 폐기물함량의 증가에 따라 증가하였다.

• Geotechnical Engineering
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• v.30 no.2
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• pp.21-26
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• 2014

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.2
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• pp.253-259
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• 2012

Disposal of high amount of coal combustion by-products, such as fly ash and bottom ash, is of a great concern to the country, due to the huge treatment cost and land requirement. On the other hand, those coal-ash wastes are considered to have desirable characteristics that may improve physical, chemical, and biological properties of soils. Especially, compared with fly ash, bottom ash has a larger particle size, porous surface area, and usable amount of micronutrients. In the present study, we examined bottom as a soil amendment for mitigating $CO_2$ emission and enhancing carbon sequestration in soils fertilized with organic matter (hairy vetch, green barely, and oil cake fertilizer). Through laboratory incubation, $CO_2$ released from the soil was quantitatively and periodically monitored with an enforced-aeration and high-temperature respirometer. We observed that amendment of bottom ash led to a marked reduction in $CO_2$ emission rate and cumulative amount of $CO_2$ released, which was generally proportional to the amount of bottom ash applied. We also found that the temporal patterns of $CO_2$ emission and C sequestration effects were partially dependent on the relative of proportion labile carbon and C/N ratio of the organic matter. Our results strongly suggest that amendment of bottom ash has potential benefits for fixing labile carbon as more stable soil organic matter, unless the bottom ash contains toxic levels of heavy metals or other contaminants.