Cenospheres are a by-product of the coal combustion process in electrical power plants, which are usually generated together with fly ash. In most carbon power plants the fly ash is collected in electro filters and disposed of in wet slurry in artificial lagoons, which are sometimes extended to several square kilometres.
The fly ash, together with the cenospheres, is pumped from the coal combustion power plant to the lagoons in wet slurry form where it is finally dumped. In new power plants there is a tendency to dispose of the fly ash in dry form, and many parties have attempted to recover dry cenospheres directly from fly ash. However, these attempts do not play an active role in the world market yet.Cenospheres harvestingDue to the nature of their low effective density, which is usually around 0.7 to 0.8 g/ccm, cenospheres are much lighter than fly ash, which has an effective...