Cenospheres can have densities varying from 2.6 g/cm³ down to 0.2 g/cm³.

Recovery potentials of cenospheres from two bituminous coal fly ashes were examined.

Cenosphere contents were determined on the basis of point and area estimations.

Separation efficiency was evaluated by yield, cenosphere content and cenosphere recovery.

The most efficient cenosphere separation process was found to be wet sieving.