Effect of Regenerated-Foundry Sand on the Mechanical Properties of Core

Abstract

Metal foundries use high quality sand in the casting process and produce vast amounts of used foundry sand (UFS). Thus, in order to make the best use of foundry sand in the casting process, it is essential to demonstrate an appropriate recycling method and verify the influence of regenerated foundry sand (RFS) on the mechanical properties of core. In this study, physical and chemical characterizations were conducted on the RFS and the physical properties of cores containing different proportions of RFS were investigated with respect to the flexural strength. The UFS produced in controlled conditions was recycled by a wet type method and the regular foundry sand was replaced with varying proportions of RFS by weight (0, 20, 40 and 60 wt. %). Although the gradation of RFS was analogous with the regular foundry sand, the flexural strength test indicated that the sand mixture with 20 wt. % replacement of regular foundry sand was appropriate for core making without a drastic decrease of flexural strength. The flexural strength decreased with the increase of RFS contents at replacement proportion more than 20 wt. %.