In compliance with current European and national regulations, in order for a given waste material to be qualified as a secondary raw material, and not as “waste”, a series of general conditions must be met, and other additional conditions specific to each type of material must be respected.
In the case of glassy sand, a by-product of the treatment process of ready-to-furnace cullet, the regulations prescribe, among other things, that the content of ceramic particles in the fraction below 1 mm, determined by gravimetry after optical selection, must be less than 1500 ppm.
For this determination there is currently no standardized or official method, so Stazione Sperimentale del Vetro in collaboration with Co.Re.Ve. and Assovetro has developed and validated a special testing methodology, later recognized as Reference Practice (“Prassi di Riferimento”) by the Italian regulatory body, UNI.
Through this analytical protocol it is possible to reliably evaluate the content of ceramic particles in the glassy sand, allowing to objectively qualify the material either as a secondary raw material or as waste.