Process for obtaining highly porous charred diatomaceous filtrating agents free of cristobalite and filtrating agents thus obtained

摘要

Calcination of diatomite is performed within a spiralling gas stream at high temperature, in which a ring of refractory beads remains sustained, within which ring the controlled calcination and agglomeration of the diatomite particles takes place. The amorphous structure of the silica is preserved; highly permeable filter agents which are practically free from cristobalite are thus obtained.