Reclamation of Used Molding Sands

Abstract

In this chapter, the main attention is focused on the theoretical and practical aspects of the reclamation of the molding and core sands. The definition and methods of reclamation characteristics for the initial and proper processes associated with the basic operations of the matrix from spent molding sands are shown. Within the theoretical description of the mechanical reclamation process the occurrence of these so-called elementary operations were highlighted, that result in the removal of waste of binding materials from the surface of the matrix (sand grains), and which include friction, abrasion and crushing. The next section discusses the most common, practical solutions for reclaimers used in methods for the dry reclamation—the vibrating reclaimer used for reclaiming the molding sands matrix, which has a good susceptibility to reclamation of spent furan sands, the pneumatic reclaimer, which is used to reclaim the molding sands matrix that are harder to reclaim, and the thermal regenerator, used in the case of the reclamation of molding sands with organic binders, where the effect of the removal of the binding material from the grains is up to 100 %. It also presents methods for combined pneumatic-thermal-pneumatic reclamation, used mostly for the reclamation of various sands from different technologies. The so-called unconventional methods of reclamation are mentioned at the end, where mechanical-cryogenic reclamation performed at about −80 °C is discussed.