Dolomite flour fractions (particle size from below 10 mu m to below 250 mu m) were granulated in a drum granulator (0.5 m in diam., 0.4 m in length, drum filling degree 0.1, rotational speed 0.331s) under continuous wetting with humid air (0.3 MPa) to agglomerate the charge. The increasing humidity of dolomite resulted in an increase the granule formation rate but in decrease in the homogeneity of the granulate.