STUDY OF TECHNOLOGICAL SLUDGES BY RADIO-FREQUENCY PERMITTIVITY MEASUREMENT.

Presumably during concentration of sludges 'adhesive joints' bonding the particles are formed from the surface coatings of the particles. These surface coatings play a very general and important part in sludges. The authors used nondestructive physicochemical test methods for their study. Because of their high content of water and hydroxides, the surface layers constitute a polar component of the systems, and they may be studied effectively by the radio-frequency permittivity method, whereby information on the dynamics of charge carriers or polar molecules can be obtained from the dissipation of energy and phase shift of the electromagnetic field in the specimen. Results show that the disappearance of megahertz dispersion when sludges are concentrated indicates that these associations become 'included' in the adhesive joints in the course of concentration. It follows the polar associations, represented in permittivity studies as nanosecond oscillators, are important elements of the adhesive joints, effectively forming them but becoming incapable of polarization in an external magahertz field.