Organic binders that are used in sand casting emit high amounts of hazardous pollutants and volatile organic compounds during the casting process. Inorganic binders do not emit harmful gases and are widely used in aluminum casting processes. However, there is a paucity of studies on the reuse of waste sand using inorganic binders in casting processes. In the study, waste sands using an inorganic binder and a powder were recycled via wet regeneration and the effects of residual powder on regenerated sand were analyzed. The wet regeneration of molding and casting sands was performed by cleaning, followed by grinding in a 0.2-M KOH solution and then removing the residual binder using water. The molding sand was regenerated to the same level as the raw sand via the 0.2-M KOH solution followed by water cleaning twice. The casting sand removed most of the binder via additional water cleaning for the regeneration condition of the molding sand. Although the powder was completely removed from the regenerated molding sand, the regenerated casting sand remained used powder; the residual powder had a 78% performance. Thus, the regenerated casting sand was reusable only when adding binder without powder.

砂型铸造中使用的有机粘合剂在铸造过程中会释放大量有害污染物和挥发性有机化合物。无机粘合剂不会散发有害气体，并广泛用于铝铸造工艺中。然而，关于在铸造过程中使用无机粘合剂对废砂进行再利用的研究很少。在研究中，使用无机粘合剂和粉末的废砂通过湿法再生进行了回收，并分析了残留粉末对再生砂的影响。通过清洁进行型砂和型砂的湿再生，然后在0.2 M KOH溶液中研磨，然后用水除去残留的粘合剂。通过0.2-M KOH溶液将型砂再生到与生砂相同的水平，然后水洗两次。对于型砂的再生条件，型砂通过额外的水清洗除去了大部分粘结剂。尽管从再生型砂中完全除去了粉末，但再生型砂仍然是用过的粉末。残留粉末具有78％的性能。因此，仅当添加不含粉末的粘合剂时，再生的铸砂才可重复使用。