Transformation Behaviors of Lead During Thermal Treatment of Heidaigou Coal

The transformation behaviors of lead in a Chinese bituminous coal, Heidaigou coal, during pyrolysis under N-2 and H-2 were studied. Behaviors of Pb in the derivative chars at 1,000 degrees C during gasification and combustion were also performed. The results show that most lead in coal releases into a volatile phase above 900 degrees C under N-2. In comparison with N-2, H-2 promotes the release of lead during coal pyrolysis in some extent, especially for the lead remaining in the residues, which is mainly bound to aluminosilicates. For lead in the derivative chars at 1,000 degrees C, part is released into a volatile phase during gasification and combustion, the other remaining in the solids is still remaining in the residues, which does not transform to other solid forms.