Mercury reduction in hard coal cleaning processes in Poland – the technology and the environmental impacts

Coal cleaning is listed among the methods of mercury emissions reduction from the point of view of coal utilisation processes. The article quantifies the content of mercury in Polish hard steam coals, the charge of mercury and, for around 20 Polish Coal Preparation Plants (CPP), the split of mercury charge in raw coals between commercial coal products and waste. The mean mercury content in Polish hard steam coal is presented also. The differences between the washability (in terms of mercury behaviour) of different size fraction of raw coal are discussed and emphasized. Coal cleaning, giving us the benefit of cleaner fuel production, is accompanied by waste release. Waste from coal cleaning may be regarded as one of the sources of the release of mercury to the environment, what wasn’t the object of in-depth analyses so far. The annual charge of mercury in waste from hard steam coal cleaning in Poland was assessed and emissions of mercury from waste dumps as well as the increase of the mercury concentration in the surrounding soils are discussed.