Mercury Removal and Ash Reduction from Coal by an Air Dense Medium Fluidized Bed

This study focused on the occurrence of mercury in coal and the effectiveness of mercury and ash removal by an air dense medium fluidized bed (ADMFB). Results of the study revealed that there was a linear correlation between the mercury content, ash content and density of coal. This was attributed to the fact that mercury mainly exists in high density minerals containing elements with a certain affinity for mercury such as silicon, aluminum, iron, titanium, potassium, sodium, chloride, zinc, and magnesium. There is therefore a good correlation between the separation efficiency of ADMFB and the quality of the clean coal, as well as the overall removal of mercury. By optimizing the operating conditions based on the fitting models, clean coal with a mercury content of 0.0841 ppm and a separation efficiency exceeding 99.8% was obtained. The desirability of the separation effect optimized by fitting models was 0.999. Based on these results, it was concluded that ADMFB is an effective way to remove mercury from coal and reduce its ash content.