Sand reclamation

摘要

A foundry sand composition which comprises particulate sand, aqueous sodium silicate as binder and an alkylene carbonate as hardener and which after use for moulds and/or cores in metal casting can be reclaimed for reuse by an attrition process contains before use no more than 11% by weight of alkylene carbonate based on the weight of aqueous sodium silicate and during the reclamation process has a residual moisture content of less than 0.8% by weight as determined by loss on ignition on 550 DEG C.