Experiments have been carried out to determine the minimum inverse fluidization velocity using single and binary systems of four different solids of polymeric origin, and four different non-Newtonian liquids in two different columns. Empirical correlations have been developed to predict the minimum inverse fluidization velocity as a function of physical and dynamic variables of the system. Statistical analysis of the correlation suggests that is of acceptable accuracy with correlation coefficient more than 0.99. (C) 2010 Elsevier B.V. All rights reserved.