The reclamation of clay–resin mixed waste sand (CRMWS) reused over multiple cycles is difficult, while the commonly used thermal–mechanical reclamation process has some major drawbacks with regard to high acid consumption and low rebonding efficiency in the reclaimed sand. In this paper, a hot waste alkali liquor soaking assisted with scrubbing (HWALSS) reclamation method was proposed to reclaim CRMWS as new sand additional for the green sand molding line, as compared to the thermal–mechanical reclamation method and water scrubbing reclamation method. The properties of the reclaimed sand were investigated, and the reclamation mechanism was also discussed. The experimental results indicate that the reclamation method of HWALSS is feasible. The compressive strength (σ_24h) of HWALSS reclaimed sand bonded by sodium silicate binder is 8.17 times and 2.71 times more than that of the thermal–mechanical reclaimed sand and the water scrubbing reclaimed sand, respectively. Morphological analysis reveals that the surface of HWALSS reclaimed sand is both smooth and clean, and the quantity and area of the bonding bridges of the sodium silicate bonded sand are found to be large compared to those of the thermal–mechanical and water scrubbing reclaimed sand, which are the main reasons for the improvement of the compressive strength.

在多个循环中重复使用的粘土-树脂混合废砂（CRMWS）的回收非常困难，而常用的热力机械回收工艺在再生砂中的高酸消耗和低粘结效率方面存在一些主要缺点。本文提出了一种热废碱液洗涤联合洗涤（HWALSS）的方法，与热机械再生方法和水洗再生方法相比，将CRMWS回收为生砂造型线的新砂。研究了再生砂的性质，并探讨了其再生机理。实验结果表明，该方法是可行的。抗压强度（σ _24小时）用硅酸钠粘合剂粘结的HWALSS再生砂分别是热机械再生砂和水洗再生砂的8.17倍和2.71倍。形态分析表明，HWALSS再生砂的表面既光滑又清洁，与热机械和水洗再生砂相比，硅酸钠粘结砂的键合桥的数量和面积大，这是提高抗压强度的主要原因。