Coal Calorific Value after Physical and Chemical Cleaning

Abstract

In this study a total of 12 coal sample was collected. 7 of these samples are local coal samples and 5 of them is exported coals. These coals samples were fractionated into two size groups, i.e. -10+3.15, -3.15+05. Float and sink analysis was performed on this two size groups of samples with Ca(NO3)2 medium at the density of 1.50 g/cm3. Latter within the scope of this study, chemical cleaning was employed on this samples. Chemical cleaning on coal samples was carried out with acids (HF and HNO3) at specific conditions. Samples have different calorific values after physical and chemical cleaning. Although some impurities have been removed with both cleaning methods, physical cleaning resulted in higher ash content coals at the end while with chemical cleaning almost no ash content coals were obtained. However, it was observed the fact that chemical cleaning resulted lower calorific values of samples. This might be because of chemical cleaning results in the decomposition of the coal matrix structure.