Effects of different kinds of coal on the speciation and distribution of mercury in flue gases

Laboratory-scale experiments on dropper tube coal combustion furnace with six kinds of coal were carried out, and the speciation and distribution of mercury in the flue gas were studied. The analyzed raw coals included Tangshan bituminous coal, Gaoping anthracite coal, Liupanshui lean coal, Xiaolongtan lignite coal, Indonesia lignite coal, and Yichang lignite coal. The combustion experiments were conducted at temperature of 900 °C, 1000 °C, 1100 °C, 1200 °C, respectively. The results show that, the content of gaseous element Hg in flue gas increased with the rising temperature of combustion and flue gas, for anthracite coal and lean coal with higher coal rank, the content of particle Hg in flue gas reached 10-15% while the content was lower than 5% for lignite coal with lower coal rank, and the percentage of gaseous mercury increases with the increase of the content of sulphur in coal.