• 지질공학
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• 제23권1호
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• pp.19-27
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• 2013

본 연구에서는 강원도 삼척시에 위치한 도계 석탄폐석 적치장 사면과 적치장 하부의 자연사면에서의 변형을 조사하고, 이를 분석하였다. 석탄폐석 적치장 사면과 하부 자연사면의 거동을 조사하기 위하여 폐석적치장 상부에 신축변위계와 강우계를 설치하고, 폐석적치장 하부 자연사면에 지중경사계를 설치하였다. 신축변위계를 이용하여 폐석적치장 상부의 변위를 측정한 결과 누적강우량이 증가함에 따라 석탄폐석 적치장 사면 정상부에서 변위는 증가하는 것으로 나타났다. 한편, 지중경사계를 이용하여 폐석적치장 하부 자연사면의 변위를 측정한 결과 누적강우량이 증가함에 따라 적치장 하부 자연사면의 최대수평변위는 증가하는 것으로 나타났다. 그러나 폐석적치장 하부 자연사면에서 지하수위는 강우에 따른 변화가 없는 것으로 측정되었다. 계측결과에 따르면, 석탄폐석 적치장의 변형은 강우와 밀접한 관계가 있음을 확일 할 수 있다. 석탄폐석 적치장 사면은 강우침투로 인하여 단위중량이 증가하게 되고, 이는 석탄폐석 적치장 사면의 변형을 유발하였다. 그리고 적치장 하부 자연사면의 변형은 강우침투로 인한 석탄폐석 적치장의 하중증가에 의해 발생된 것으로 판단된다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제17권1호
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• pp.1-7
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• 2012

Selection of appropriate liner type would be the most important factor to prevent groundwater contamination by leachate from waste management site. This report introduces the IWEM (Industrial Waste Management Evaluation Model) developed by US EPA to evaluate the potential pollution of groundwater under the waste management unit and to suggest an appropriate type of liner, and provides with the results of IWEM application to a coal-ash landfill site in Korea as a case study. IWEM uses a standard method using a database, a decision-making process based on site characteristics, and the user-friendly input-and-output system. Authors evaluate this model to be applicable in Korea provided that the database is replaced into local data.

• Asian Journal of Atmospheric Environment
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• 제2권2호
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• pp.102-108
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• 2008

In China, energy and environmental problems are becoming serious owing to rapid economic development. Coal is the most problematic energy source because it causes indoor and outdoor air pollution, acid rain, and global warming. One type of clean coal technology that has been developed is the coal-biomass briquette (or bio-briquette, BB) technique. BBs, which are produced from pulverized coal, biomass (typically, agricultural waste), and a sulfur fixation agent (slaked lime, $Ca(OH)_2$) under high pressure without any binder, have a high sulfur-fixation effect. In addition, BB combustion ash, that is, the waste material, can be used as a neutralization agent for acidic soil because of its high alkalinity, which originates from the added slaked lime. In this study, we evaluated the suitability of alternative biomass sources, namely, aquatic plants, as a BB constituent from the perspective of their use as a source of energy. We selected three types of aquatic plants for use in BB preparation and compared the fuel, handling, and environmental characteristics of the new BBs with those of conventional BBs. Our results showed that air-dried aquatic plants had a higher calorific value, which was in proportion to their carbon content, than agricultural waste biomass; the compressive strength of the new BBs, which depends on the lignin content of the biomass, was high enough to bear long-range intracontinental transport in China; and the new BBs had the same emission control capacity as the conventional BBs.

• 한국수소및신에너지학회논문집
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• 제26권1호
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• pp.64-70
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• 2015

Organic Rankine cycle (ORC) is an useful cycle for power generation system with low temperature heat sources ($80{\sim}400^{\circ}C$). Since the boiling point of operating fluid is low, the system is used to recover the low temperature heat source of waste heat energy. In this study, a ORC with R134a is applied to recover the waste energy of condenser of coal fired power plant. A system model is developed via Thermolib$^{(R)}$ under Simulink/MATLAB environment. The model is composed of a refrigerant heat exchanger for heat recovery from coal fired condenser, a drum, turbine, heat exchanger for ORC heat rejection, storage tank, water recirculation pump and water drip pump. System analysis parameters were heat recovery capacity, type of refrigerants, and types of turbines. The simulation model is used to analyze the heat recovery capacity of ORC power system. As a result, increasing the overall heat transfer coefficient to become the largest of turbine power is the most economical.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.7-10
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• 2003

The amount of coal ash has been increasing and development of effective use is urgently needed. Various by-products and waste are expected to be used as resources from the point of reduction in environmental load. This is an experimental study to compare the properties of high volume coal ash concrete using the reclaimed coal ash. For this purpose, the mix proportion of concrete according to the content ratio of below 5mm reclaimed coal ash (0.65, 0.70, 0.75 and 0.80). And then air content, slump, compressive strength test were performed. According to test results, it was found that the compressive strength of reclaimed coal ash concrete was similar to the content ratio of below 5mm reclaimed coal ash. And the slump of reclaimed coal ash concrete decreased as the content ratio of below 5mm.

• 한국토양비료학회지
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• 제47권5호
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• pp.356-361
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• 2014

The coal fly ash (CFA) may be utilized as an extender for organic waste composting at the same time fully expected to solve all industrial waste disposal and sawdust tribe. The main objective in this study was to evaluate the effect of CFA addition as a bulking agent for swine manure composting. To determine the suitable addition rate of CFA as a bulking agent, 0, 10, 20 and 30% of saw dust were mixed with 30, 20, 10 and 0% of coal fly ash, respectively. Compost quality for swine manure composting was to evaluate temperature, pH, C/N ratio, and phytotoxicity as germination index. Stability of compost increased with increasing levels of CFA as bulking agent during swine manure composting due to the high alkaline materials including CFA. C to N ratio in treatment added CFA was higher than that of the control without CFA. After finishing composting, germination index of lettuce and cabbage in swine manure compost added 10% of CFA was similar to the control, all the heavy metal contents were far below the stipulated standard for organic farming. These results indicated tahr coal fly ash as bulking agents might be alternative materials to save saw dust and apply industrial products for swine manure composting.

• 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.

• 유기물자원화
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• 제7권1호
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• pp.43-52
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• 1999

본 연구는 축산분뇨 퇴비화시 부자재인 톱밥을 석탄회로 대체하기 위하여 수행하였다. 축산분뇨와 톱밥의 혼합비율을 부피비 1:1로 고정하고 이때 톱밥을 어느 정도 석탄회로 대체 가능한지를 조사하였다. 각 혼합비율에 대해 조사된 톱밥과 석탄회의 혼합비율은 부피비로 40:10, 35:15, 30:20, 25:25, 20:30, 15:35, 10:40이었다. 축사에서 스크레퍼 방식과 슬러리 방식에 의하여 배출되는 축산분뇨, 톱밥과 석탄회를 앞에서와 같은 혼합비율로 섞은 부자재를 부피비 1:1로 혼합하여 퇴비화하면서 온도, 수분, pH, 유기물, 질소 및 유기물/질소 비 등을 조사하여 다음과 같은 결과를 얻었다. 온도의 변화는 슬러리 방식보다 스크레파 방식에서 톱밥비율이 높을수록 빨리 최고온도($63.5^{\circ}C$)에 도달하였다. 수분 함량의 변화는 스크레파 방식 및 슬러리 방식 공히 톱밥과 석탄회를 부피비로 동일비율(1:1) 혼합하였을 때 42 %와 54 % 범위의 수분함량으로 발효에 비교적 좋은 조건을 유지하였다. pH는 분뇨, 톱밥, 석탄회 비율 50 : 25 : 25 투입시 전체적으로 pH 7~10으로 약알카리성 내지 알카리성이었다. 유기물함량은 톱밥 혼입량이 석탄회보다 많을수록 증가되나 퇴비화가 진행됨에 따라 별다른 변화는 보이지 않았다. 질소함량은 톱밥 혼입량 증가에 따라 늘어났으나, 발효과정 진행에 따라서는 일정한 경향을 나타내지 않았다. 유기물/질소 비는 톱밥 혼입량이 증가할수록 증가하였지만, 발효과정 중 큰 변화는 볼 수 없었다.

• 에너지공학
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• 제21권4호
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• pp.373-377
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• 2012

Among the fossil fuels, the brown coal is a great deal of resources. However, it is hardly used due to the high moisture content and low calorific value. It has both the week points such as spontaneous combustion and high volatile content and the strong points such as the low-sulfur and low ash content. If we overcome these week points, the using amount of brown coal would be increased. Also, it is well known that biomass is one of the important primary renewable energy sources because of carbon neutral energy. Furthermore, the utilization of biomass has been more and more concerned with the depletion of fossil fuel sources as well as the global warming issues. Combustion and thermal decomposition of biomass is one of the more promising techniques among all alternatives proposed for the production of energy from biomass. In this study, combustion of brown coals and mushroom waste was done. Mass change of samples and emission of hydrocarbon components were measured. As the results, we obtained combustion rate constant. Also activation energy was calculated in char combustion step. Hydrocarbon components were more generated in low oxygen concentration than high. Emission amount of hydrocarbon components in mushroom waste was significantly increased comparing to brown coal.

• 한국결정성장학회지
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• 제23권3호
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• pp.146-151
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• 2013

본 연구에서는 석탄 바닥재와 준설토(7 : 3, 무게비율)로 제조된 인공골재의 물성에 미치는 폐촉매 유리질 슬래그(이하 폐유리로 칭함) 첨가 영향을 평가하였다. 특히 인공골재의 비중 및 흡수율 결과를 미세구조와 연계하여 그 발포특성을 고찰하였다. $1050{\sim}1150^{\circ}C$ 범위 내에서 인공골재 비중은 소성온도와 함께 약간 증가되었으나 그 이상의 소성온도에서는 감소하여 발포경향을 나타내었다. 폐유리 첨가량이 증가할수록 인공골재의 발포특성은 억제되었으며, 비중은 증가하는 경향을 보였다. 한편 인공골재 흡수율은 소성온도의 증가와 함께 감소하였다. $1200^{\circ}C$ 이상의 소성온도에서 표면에 균열이 발생함과 동시에 다량의 액상이 형성되었으나, 이러한 현상들은 폐유리를 첨가함으로서 제어할 수 있었다. 본 연구에서 제조된 인공골재의 비중은 1.1~1.6, 흡수율은 8~22 % 범위값을 나타내어 인공경량골재의 KS 기준을 만족하였다.