In this paper the examination results of chemical and phase composition as well as wastes graining from the semi-dry flue
gas desulfurization (FGD) have been presented. The wastes contain mainly semi-hydrate calcium sulfite and calcium sulfate.
The phase composition changes of wastes at the temperature of 350 and 600°C have been determined. On the basis of carried
out examinations, possibilities of flue gas desulfurization wastes utilization in building materials production (sulfite and
anhydrite cement) are proposed.