Method for regenerating water-glass-bonded used foundry sands

摘要

In the foundry, waterglass is employed as moulding-material binder which, after the moulding, is cured by gassing with acidic gases. Foundry sands of this type can generally be used only once and must be disposed of after the casting process. The new method is to enable the foundry sand to be treated in such a way that it can be reused without restriction. The water-glass-bonded foundry sand is heated after destruction of the sand lumps in a furnace (4) to a temperature exceeding 200 DEG C, as a result of which the troublesome constituents are destroyed or converted, so that there is no disadvantageous influence on a further moulding process. Subsequently, the sand is cooled to processing temperature in a cooler (5). <IMAGE>