The content of combustible elements in solid mineral fuels (carbon, hydrogen,
etc.) are very important, since they most directly affect the heat value. It
should be noted that the fuel heat value depends on many other constituents,
such as ash and moisture. In this paper, special attention has been paid to
carbon content. In solid mineral fuels, carbon is found alone or bound in
the form of various compounds. One of them is mineral carbonate compounds
bound as carbonate carbon, which originates from absorbed carbon dioxide
from atmosphere. Determination of carbonate carbon content of solid mineral
fuels was performed by standard gravimetric method (according to ISO 925:
2019), and newly developed instrumental method, using thermogravimetric
analyzer LECO TGA 701. Comparison of obtained experimental results was done.
Four types of coal, Kolubara lignite, Kostolac lignite, brown coal and
control coal sample were included in experimental analysis. In addition,
moisture in the samples was also determined using analytical method and
inspected using LECO TGA 701 thermogravimetric analyzer, as well as total
carbon content using the LECO CHN 628 elemental analyzer. An analysis and
comparison of the obtained results was performed, and comments and
conclusions are presented. The experiments were done in the department for
fuel characterization, Laboratory for Thermal Engineering and Energy,
Institute of Nuclear Sciences Vinca.