• 한국지하수토양환경학회지:지하수토양환경
• /
• 제15권6호
• /
• pp.72-80
• /
• 2010

Possibility of the usage of sludge generated in coal mine drainage treatments as a briquette additive was investigated by the combination of industrial, elemental, and combustion experiments. A series of briquettes having 2% and 6% of sludge were used for the experiments. Compared to the control sample, our results show that all experimental values for the briquettes are very similar. In particular, it is worthy to note that there is no obvious difference in calorific values for the briquettes containing 2% or 6% of sludge. The calorific values are 4,250~4,360 kcal/kg, 4,240~4,250 kcal/kg, 4,180~4,210 kcal/kg, and 4,270~4,360 kcal/kg for the control sample, briquette containing 6% of Hambaek sludge, briquette containing 6% of Hamtae sludge, and briquette containing 2% of Hambaek sludge, respectively. Results of ash fusion temperature show that the temperature is greater than $1,550^{\circ}C$ for the control sample. However, the temperature for the briquettes with 6% of Hambaek sludge and 2% of Hambaek or Hamtae sludge is $1,510^{\circ}C$. For a briquette containing 6% of Hamtae sludge, the temperature of ash fusion is $1,530^{\circ}C$. After combustion, environmental impacts of the briquettes with sludge were tested. Little environmental influence was observed for the combusted briquettes with sludge.

• 한국입자에어로졸학회지
• /
• 제17권1호
• /
• pp.1-8
• /
• 2021

The purpose of this study is to assess respirable crystalline silica (RCS) exposure levels in workers who collect and dispose used coal briquette ash (CBA) in sanitation companies that are subcontracted by one medium-sized local government on the collection of municipal household waste (MHW), and to analyze the quartz content in CBA. When the CBA powder that undergone specialized pretreatment in several steps were subjected to mineral identification and quantitative analysis using X-ray diffraction (XRD), it was found that quartz represented 18%, and in addition, mullite, and plagioclase were included. For two CBA collectors, samples were collected by the personal sampling evaluation method. After respirable dust was collected in accordance with the National Institute for Occupational Safety and Health 7500 method, the concentration of quartz was analyzed using XRD. Meanwhile, a portable real-time dust monitor (Sidepak AM520, TSI Inc., USA) was also used to observe the dust exposure level for each time zone and job task. The RCS exposure level of one worker was as high as 0.024 mg/㎥, which was the American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Values (TLV) level. The other worker also exhibited a concentration of 0.013 mg/㎥, which was more than half of TLV. The Sidepak results revealed that the work of collecting CBA and loading it onto a vehicle was hardly exposed to the dust of a significant level. It was found, however, that the work of transferring the collected CBA to a container through a conveyor belt was exposed to a very high average respirable dust concentration of 2.238 mg/㎥. The results of this study confirmed that quartz, which is crystalline silica and a carcinogen, is contained in CBA, one of municipal household waste (MHW), in high concentration. It was also confirmed that workers are exposed to high RCS concentrations while transferring collected CBA into a container. Although each local government in South Korea handles CBA in different ways, it is imperative to investigate the CBA exposure level of sanitation workers and improve their working conditions.

• 한국건설순환자원학회논문집
• /
• 제11권1호
• /
• pp.16-24
• /
• 2023

미연탄을 사용하는 화력발전소에서 발생되는 석탄재는 Si, Al, Fe 성분을 포함하고 있으며, 이들 성분은 시멘트 클링커에 제조에 필요한 주요성분이다. 특히 Al, Fe 성분은 시멘트 클링커의 간극상을 형성하는 성분으로 시멘트 클링커의 소성에 중요한 영향을 미친다. 본 연구에서는 시멘트 클링커의 원료로서 다량의 석탄재를 함량별로 적용하여, 석탄재를 적용한 시멘트 클링커의 소성온도별 광물형성 과정을 확인하고자 하였다. 석탄재를 다량 적용한 시멘트 클링커는 1050~1150 ℃의 소성온도 구간에서 중간상이 생성되는 것을 확인하였고, 이는 석탄재의 함량이 증가할수록 생성량이 증가하였다. 석탄재의 첨가로 생성된 상은 1350 ℃ 이상에서 칼슘실리케아트상과 간극상으로 전환되어 소멸되는 것으로 예상된다. 시멘트 클링커의 일반적인 소성온도인 1450 ℃에서는 다량의 석탄재를 적용한 시멘트 클링커는 순수원료를 사용하여 제조한 기준 시멘트 클링커와 동등수준의 잘 발달된 광물을 형성하였다.

• 청정기술
• /
• 제29권1호
• /
• pp.22-30
• /
• 2023

몽골은 전 세계에서 대기오염문제가 매우 심각한 나라 중 하나이다. 그 원인으로는 몽골 울란바타르시 내 게르촌에서 사용되는 저급연료의 난방연소 때문이다. 본 연구에서는, 몽골 울란바타르시 게르촌에서 사용되고 있는 저급연료 및 몽골 폐식용유의 연료품질을 분석하였으며, 전통난로와 시작품 연소난방장치의 연소테스트를 통해 환경성을 평가하였다. 또한 인체위험도 분석을 통해 난방장치의 대체효과를 평가하였다. 연료특성분석 결과, 몽골석탄 중 조개탄은 회분, N, S 함량이 높은 이유로 환경성이 상대적으로 안좋은 것으로 분석되었다. 또한 3종의 석탄에 비해 폐식용유를 연소하였을 때, 대기질 개선효과가 높은것으로 나타났다. 몽골 전통난로를 시작품난로(폐식용유 사용)로 교체할 경우, 몽골 울란바타르시의 대기환경문제를 개선할 수 있는 효과가 있을 것으로 판단된다.