热再生石英砂改性机理

Modification Mechanism of Properties of Hot-reclaimed Quartz Sands

与同种类的新砂相比,热再生砂的铸造工艺性能明显得到了改善,主要原因是对旧砂热再生过程中,由于对砂的高温热作用,使砂的晶体结构略有变化,砂的粒形更趋圆整,砂粒表面吸附物的燃烧及分解引起了砂粒表面的物理及化学变化,增强了砂粒的表面活性,降低了砂的发气性,改善了砂的铸造工艺性能。

Compared with new sands, the foundry properties of hot-reclaimed quarts sands are improved obviously. The crystal structure of quartz sands was modified somewhat by high temperature and the shape of grains becomes more round after hot-reclamation. Since the adsorbate on grain surface was burn off or decomposed to make physical and chemical change, the surface activity of grains improves and the gas release of sands decreases, which can improve the foundry properties.