The change of the elemental composition of a layered charge consisting of particles of sulfur brown coal and marble during oxidation in a furnace heated to 1200°C has been studied. It has been determined that as coal burns out, the sulfur was released into the gas phase and partially absorbed by marble. At the final oxidation temperature (1200°C), approximately 5% of the initial sulfur content remains in the coal, about 40% was absorbed by the marble, and the remaining 55% passes into the gas phase.