The limitations of correlations used in the literature for calculation of the minimum fluidization velocity of coarse particles (of group D of the Geldart classification(2,3)) have been proven and original correlations for calculation of the minimum fluidization velocity have been proposed. The Ergun type correlation proposed suitably fits the experimental results up to a value of the Archimedes modulus of 5.8 x 10(7). An original correlation for calculation of the expansion of fluidized beds formed by group D particles has been proposed as a function of the ratio of drag and gravitational forces.