The behaviour of a strongly fluidising system composed of iron and gla
ss particles with similar minimum fluidising velocities was studied, u
nder steady and also under unsteady state conditions. The parameters w
hich determine fluidisation behaviour were shown to be the depth of th
e bottom layer and the fluidising velocity, and, based on these parame
ters, a correlation was developed for predicting segregation. The down
ward relative velocity of jetsam particles in the emulsion was measure
d by two independent methods, and it was also demonstrated that under
the conditions of this study only about 1% to 3% of the jetsam particl
es reaching the layer interface is carried into the upper layer.