method for regeneration of used sand in foundry, regenereerinrichting and regenerated product.

摘要

Regeneration of clay-bonded used foundry sand for reuse instead of new sand. A dry mass of used sand is rubbed for such a length of time, is accelerated suddenly and delayed, and is freed continuously of fine components, until the fine matter, active bonding clay and oolitization degree fall below certain threshold values such that the regenerated product substantially gains the characteristics of new sand. An apparatus for regeneration treatment contains a horizontal revolving sand drum (10), an impact rotor (30) disposed inside said drum in the area of the fall stream (46) of the used sand and a pneumatic dust removal device (36) disposed in the inside of the drum. A chemical secondary treatment of the regenerated product can be carried out advantageously in the same installation in order to bind remaining fine matter to the surface of the grains of sand and simultaneously to seal the pores of the grains.