Application of TG–DTG analysis and centrifugal separation in the investigation of less combustible constituents in coals

Three coals of Yangquan anthracite (YQ), Huainan bituminous coal with a medium amount of volatile matter and Shenfu bituminous coal with a high amount of volatile matter (SF) are used for the investigation of less combustible constituents (LCC) . It has been concluded that some less combustible constituents exist in coals by means of centrifugal separation (CS) with gravity liquids and thermogravimetric analysis (TG) with a Du Pont-2100 thermal balance. The constituents always lie in the separation fraction with the specific density, which differs from each other in various coals. The LCC in coals always give a lower value of the maximum combustion rate, and also lower kinetic parameters, like activation energy (E) and apparent pre-exponential factor (k0).