Patent ID: 6554049
Filing Date: 2003-04-29
Classification: B22C

Abstract:
A process for recovering sand, bentonite clay and organic additives from the foundry waste produced by a green sand foundry, the foundry waste being formed from bag house dust and molding waste, the process comprising:forming an aqueous slurry of the bag house dust, hydraulically separating the slurry in a first hydraulic separation step into an overflow stream comprising at least 60% of bentonite clay originally in the bag house dust and an underflow stream comprising at least 60% of the sand in the bag house dust; hydraulically separating the overflow stream in a second hydraulic separation step to produce an effluent stream comprising water and less than about 5% sand in the bag house dust; and reusing the sand in the underflow stream and the bentonite clay and organic additives in the effluent stream for making green sand molds.