• 환경영향평가
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• 제8권4호
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• pp.25-35
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• 1999

Fly ash, by-product from coal fired power station, has long been regarded as a potential contamination source for heavy metals and inorganics due to their enriched concentrations and associations with particle surface. Feed coal and fly ash samples were collected from two power stations; Yongdong deliang with domestic anthracite coals and Boryong with imported bituminous coals. The coal and fly ash samples were analyzed for chemical composition and mineral components, using XRF and XRD. Batch leaching experiments were conducted by agitating samples with deionised water for 24 hours. Anthracite coals are generally higher in Al and Si contents than bituminous coals. This is due to the higher ash contents of the anthracite coal than bituminous coal. The chemistry of the two fly ash samples shows broadly similar compositions each other, except for the characteristically high contents of Cr in anthracite coal fly ash. Leaching experiments revealed that concentrations of metals gradually decreased with leachings in general. However, measurable amounts of metals were present in the effluent from weathered ash and the samples subjected to the leaching procedure. These metals are likely to indicate that the metals in fly ash were incorporated into glass fraction as well as associated with particle surface of samples. Dissolution of aluminosilicate glass would control releasing heavy metals from fly ash as weathering progresses during landfill with implication of possible groundwater contamination through fly ash landfill.

• 한국환경과학회지
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• 제25권3호
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• pp.417-424
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• 2016

The objective of this study was to evaluate the microwave drying characteristics of mixtures of chemical wastewater sludge (70~90%) and anthracite coal (10~30%) with respect to physical and economic factors such as mass, volume reduction, moisture content, drying rate and heating value when the wastes were dried at different weight mixing ratio and for different microwave irradiation time. The drying process were carried out in a microwave oven, the combined drying process with a 2,450 MHz frequency and 1 kW of power. Maximum dry rates per unit area on the microwave drying of mixtures with chemical wastewater sludge and anthracite coal were $35.5kg\;H_2O/m^2{\cdot}hr$ for Cs90-Ac10; $40.1kg\;H_2O/m^2{\cdot}hr$ for Cs80-Ac20 and $35.0kg\;H_2O/m^2{\cdot}hr$ for Cs70-Ac30. The result clearly indicated that moisture can be effectively and inexpensively removed from the wastes through use of the microwave drying process.

• 대한기계학회논문집B
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• 제25권10호
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• pp.1373-1383
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• 2001

The desulfurization characteristics of anthracite in a bench scale pressurized fluidized bed combustor are investigated. The coal used in the experiment is domestic anthracite from Kangwon Taeback area. The desulphurization experiment is performed with limestone from Chungbuk Danyang. The pressure of the combustor is maintained at 6 atm, and the combustion temperatures are 850, 900, and 950$\^{C}$. The superficial gas velocities are 0.9, 1.1, and 1.3 m/s. The excess air ratio is varied from 5 to 35%. The Ca/S mole ratios are 0.5, 1.5, 2.5 and 4.5 mole. All experiments are executed at 2m bed height. Consequently, SO$_2$ concentration in the flue gas is increased with incresing bed temperature and superficial gas velocity. However SO$_2$ concentration is decreased with incresing excess air ratio and Ca/S mole ratio.

• 한국환경과학회지
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• 제27권3호
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• pp.167-177
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• 2018

The removal characteristics of As and Se ions from aqueous solution by hexadecyl trimethyl ammonium bromide (HTMAB) modified anthracite (HTMAB-AT) were investigated under various conditions of contact time, pH and temperature. When the pH is 6, the zeta potential value of anthracite (AT) is -24 mV and on the other hand, the zeta potential value of the HTMAB-AT is +44 mV. It can be seen that the overall increase of about 60 mV. Increasing the (+) potential value indicates that the surface of the adsorbent had a stronger positive charge, so adsorption for the anion metal was increased. The isotherm data was well described by Langmuir and Temkin isotherm model. The maximum adsorption capacity was found to be 7.81 and 6.89 mg/g for As and Se ions from the Langmuir isotherm model at 298 K, respectively. The kinetic data was tested using pseudo first and pseudo second order models. The results indicated that adsorption fitted well with the pseudo second order kinetic model. The mechanism of the adsorption process showed that adsorption was dependent on intra particle diffusion model according to two step diffusion. The thermodynamic parameters(${\Delta}G^{\circ}$, ${\Delta}H^{\circ}$, and ${\Delta}S^{\circ}$) were also determined using the equilibrium constant value obtained at different temperatures. The thermodynamic parameters indicated that the adsorption process was physisorption, and also an endothermic and spontaneous process.

• 플랜트 저널
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• 제6권2호
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• pp.70-77
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• 2010

This study investigated the characteristics of co-combustion of mixed anthracite (domestic and Vietnam) and bituminous coal (Sonoma, Australia) at circulating fluidized bed boiler in Donghae thermal power plant when mixing ratio of bituminous coal is variable. Co-combustion of bituminous coal contributes to improvement in general combustion characteristics such as moderately retaining temperature of furnace and recycle loop, reducing unburned carbon powder, and reducing discharge concentration of NOx and limestone supply owing to improvement in anthracite combustibility as the mixing ratio was increased. However, bed materials were needed to be added externally when the mixing ratio exceeded 40% because of reduction in generating bed materials based on reduction in ash production. When co-combustion was conducted in the section of 40 to 60% in the mixing ratio while the supplied particles of bituminous coal was increased from 6 mm to 10 mm, continuous operation was shown to be possible with upper differential pressure of 100 mmH2O (0.98 kPa) and more without addition of bed materials for the co-combustion of mixed anthracite and bituminous coal (to 50% or less of the ratio) and that of domestic coal and bituminous coal (to 60% of the ratio).

• 자원리싸이클링
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• 제2권2호
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• pp.39-44
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• 1993

어룡탄광에서 산출되는 저질인 무연탄 슬러리를 Oil agglomeration 처리법으로 탈수하여 다음과 같은 결과를 얻었다. 저질 무연탄은 기름과 응집체(COM)를 형성하여 물과의 비중차이에 의해서 약 80%까지 분리되고 이때 COM을 만드는 각각 석유, 경유 또는 중유의 첨가량은 시료량의 10%정도이다. 무연탄에서 가연성분을 회수하고 회분을 제거할 수 있는 능력은 기름의 첨가율, 광액 농도, 광립의 입도, 교반시간, 교반강도에 크게 영향을 받는다. 최적조건인 상태에서 가연물질의 회수율은 약 95%까지 증가되었고, 회분의 함유율은 30%에서 13.5%로 감소되었다.

• 플랜트 저널
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• 제4권4호
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• pp.71-77
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• 2008

The sulfur oxides is one of important materials to come about air pollution at thermal plant consuming fossil fuel. The several flue gas desulfurization equipments are installed and operated to decrease sulfur oxides. The flue gas desulfurization of our thermal plant is designed for optimizing flue gas desulfurization technical development and research by Korea Electric Power Research Institute. We operate this desulfurization equipment. Now, our country imports nearly 97 percentage of the energy source and competes with the world for the energy because of the sudden rise of raw materials cost. The fuel cost decrease of power plants is the most important factor of the operation. The fuel used in the experiment is the domestic anthracite from Kangwon Taeback and the bituminous coal from Taldinsky Mine in Russia. This Study is experimental investigations of desulfurization characteristics for domestic anthracite power plant by increasing bituminous coal. We surveyed possible parameters and conducted the performance about desulfurization equipment in Yong Dong thermal power plant.

• 자원리싸이클링
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• 제17권6호
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• pp.57-61
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• 2008

본 연구는 페놀수지와 무연탄을 혼합한 다음 소결하여 합금철용으로 사용 가능한 코크스를 얻기 위하여 수행 되었으며 무연탄과 페놀수지를 혼합하여 성형코크스를 제조하는 경우에 있어서 코스의 강도에 미치는 여러 인자들의 영향을 검토하여 다음과 같은 결론을 얻었다. 합금철용 코크스 제조 공정은 $35{\sim}325$ mesh로 입도 조절된 저회분 함량의 무연탄에 액상 페놀수지를 6% 정도 첨가하여 혼합한 다음 $10{\sim}50\;kgf/cm^2$로 압착하여 펠릿을 제조하고, 이 펠릿을 $50^{\circ}C$에서 6시간 이상 탈수하고 $200^{\circ}C$에서 180분 동안 경화 시킨 다음 $1200^{\circ}C$에서 6시간 소결하면 $100{\sim}150\;kgf/cm^2$인 합금철용 코스가 얻어짐을 확인하였다.

• 에너지공학
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• 제17권3호
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• pp.153-160
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• 2008

유연탄, 무연탄, 그리고 두 탄종의 혼합 비율을 달리한 혼합탄에 대한 열중량 분석을 수행하여 연소반응성을 평가하였다. 무연탄과 유연탄의 혼합탄에 대한 무게 감소율이나 반응속도의 모양을 살펴볼 때 반응시 두 탄종간에 서로 영향을 미치지 않고 혼합 비율에 비례하여 두 탄종이 독립적으로 반응하는 것을 알 수 있었다. 그리고A화력 발전소에서 유, 무연탄을 50% : 50%의 비율로 혼합하고 보일러 출력을 정격대비 약 65%인 134 MW부터 정격부하인 197 MW까지 증대시키면서 보일러 내의 연소상태, 운전특성을 분석하였다. A화력발전소의 연소시험 결과 출력에 따른 보일러내의 연소상태는 전체적으로 양호한 것으로 나타났으며 출력이 증가함에 따라 공기예열기 출구의 배기가스 온도가 설계치인 $430^{\circ}C$를 훨씬 상회하여 연소용 공기의 흡인방법을 변경하여 출구 가스 온도를 조절할 수 있었다.

• 에너지공학
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• 제5권2호
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• pp.170-175
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• 1996

국내 석탄화력발전소에서 사용되고 있는 3종류의 유연탄 및 무연탄에 대해 입자 크기와 CaCO$_3$ 주입에 따른 TGA 분석을 수행하고 활성화에너지를 구하였다. 유연탄의 무게감량 시작온도는 360-38$0^{\circ}C$로 무연탄의 570~$600^{\circ}C$보다 20$0^{\circ}C$정도 낮았다. 유연탄의 활성화에너지는 입도 및 탄종에 따라 14~20kcal/mole 범위이고 무연탄은 37~55 kcal/mole로서 무연탄이 유연탄보다 활성화에너지가 매우 높았다. 석탄의 입도크기가 작아질수록 활성화에너지는 감소하였고 무게감량율과 활성화에너지값은 상관관계가 있었다. 유 무연탄의 유황분대 CaCO$_3$비율을 1:1로 주입시 유연탄은 활성화에너지 변화가 작았으나 무연탄의 경우 1~23 kcal/mole 정도로 활성화에너지가 감소하였다.