南京某燃煤电厂汞的排放特点及分布特征

Distribution Features and Emission Characteristics of Mercury in A Nanjing Coal-fired Power Plant

选择南京某燃煤电厂330 MW机组,对煤、炉渣、粉煤灰、烟尘、石灰石、石膏和烟气中的汞取样测量,探讨煤中汞在燃烧过程中的变化情况,并进一步分析汞的排放特点及分布特征。指出,煤经燃煤锅炉炉内高温燃烧后,炉渣中的汞对环境影响不明显;粉煤灰、烟尘中的汞存在富集现象,且随着粒径变细,富集程度加剧;燃煤锅炉燃烧后,随石膏排放的汞占比较大,应采取相应的防治措施。

Mercury in coal,bottom ash,fly ash,smoke dust,limestone,gypsum and flue gas were sampled and analyzed from a coal-fired power plant 330 MW unit in Nanjing.The distribution and emission characteristics of mercury were obtained based on the analysis data.The results showed that mercury in bottom ash has little effects on environment.Mercury in fly ash and smoke dust is apt to accumulate,and the accumulation increases with decreasing the particle diameter.As most of mercury discharge in company with gypsum after the burning of coal in coal-fired boiler,some measures should be taken to prevent and control the mercury pollution on the envi-ronment.