COMPARATIVE STUDY OF WASTE FOUNDRY SAND RECLAMATION TECHNIQUES

摘要

Binders (Bentonite, Phenolic resin etc.) are used for making molds and cores in the foundries. The binder present in the foundry sand becomes dead upon application of high molten metal temperature (~1400 °C). As a result, these binders forms a brittle coating on the surface of sand grains leaving them unsuitable for further use. In order to remove the dead binder coating from waste foundry sand (WFS), two types of techniques have been used namely, mechanical and thermal reclamation. This WFS after being reclaimed, mechanically and thermally, has been later compared with each other using the various tests. These tests include namely, Compressive and shear strength, Scanning Electron microscopy (SEM) and/or Optical microscopy, Total clay content, Grain fineness number (GFN), Particle size distribution, and finally loss on ignition (LOI). The above mentioned tests have been used to characterize the quality of foundry sand used in foundry industry at Kolhapur, Maharashtra, India and to test the suitability of reclaimed foundry sand for application in mold and core making in those foundry industries.