The use of sand in metal casting is a very common practice. Over 70% of all metal castings are produced via a sand casting process. In green sand clay bonded, process the sand is used over and over again after some treatment of the used demoulded ‘return’ sand. The treatment includes sieving, removal of Iron particles, cooling, water and binder addition, mixing etc.
But in case of chemically bonded sand system the mold / core strength is developed by chemical reaction or thermal process. It is not reversable. The bonded sand is re-used, introducing a certain portion of fresh sand into the mixture, but at some point the issue arises. What to do with all this Bonded Sand?
In this foundrymag.com article, "Considerations for Reclaiming Chemically Bonded Sand," the author, Jack Palmer, suggests that foundries can't ignore the potential ROI that bonded sand offers.
Here's a look at bonded sand reclamation, and the top uses for bonded sand.