Self-hardening casting compsn - contg casting sand, organic binder and setting agent- has controllable setting time and compressi

摘要

Self-hardening casting compsn. for the mfr. of moulds and mould cores. The compsn. contains casting sand, an organic binder which is an alkali metal, an alkaline earth and/or an ammonium lignosulphonate and a powdered setting agent which is essentially CaO and Al2O3 in the molar ratio 1.6-4.1 and which contains 40-98% tricalcium aluminate. The organic binder reacts with the setting agent promoting the setting of the mixt. This casting compsn. is superior to former casting compsns. since it does not have their disadvantages namely - difficult core removal, adhesion to core casings, complex hardening processes, low gas permeability and low compressive strengths.