Process for preparing cores and molds

摘要

A binder and a hardener therefor for a foundry aggregate. The binder is a resin obtained by reacting phosphoric acid with a mineral silicate. The hardener is a linear alkali metal polyphosphate, ammonium polyphosphate, a source of polyvalent cations, potassium olivine phosphate and other metal silico-phosphates or aluminum dihydrogen phosphate or mixtures there.