Binder, core sand and process for their production

摘要

A binder system comprises an aqueous alkali silicate solution containing an emulsion solution with 8-10% silicone oil, and a hygroscopic base in a ratio of 1: 4-6. The silicone oil has a boiling point of at least 250 degrees C. The alkali silicate solution has the formula: xSiO2.yM2O.zH2O (where, M = Li<+>, K<+> or Na<+>). The module Na2O/SiO2 is 2.5-3.5 with a solids content of 20-40%. The hygroscopic base is 30% caustic soda in an aqueous solution. AN Independent claim is also included for the production of a core sand mixture containing the binder system.