超细粉末硬化水玻璃砂的性能特征研究

Study on Performance Characteristics of Sodium Silicate Sand Hardened by Superfines

采用课题组配置的超细复合粉末作固化剂,研究测试了超细粉末硬化水玻璃砂的性能特征,将它与目前大量采用的酯硬化水玻璃砂在性能上作了比较,并通过SEM对常温下和800℃焙烧后粉末硬化水玻璃砂样以及酯硬化水玻璃砂样的粘结桥微观结构进行了观察。试验结果表明:超细粉末硬化水玻璃砂工艺中,当水玻璃加入量占原砂质量的3%,粉末加入量占水玻璃加入量的25%时,砂样的常温强度比酯硬化水玻璃砂的强度提高约23%,残留强度降低约76%;粉末硬化水玻璃砂对水玻璃的模数敏感度不高,硬化过程中使用高模数水玻璃将显著改善水玻璃砂的溃散性和再生回用性能;粉末硬化水玻璃砂的抗湿性远远优于酯硬化水玻璃砂。

The performance characteristics of sodium silicate sand hardened by superfines were studied, and it was compared with the performance of sodium silicate sand hardened by ester, which was adopted widely in the foundry enterprises at present. The microstructure of sand samples hardened by ultrafines or ester, including the sand samples at room temperature and roasted at 800℃, was observed by SEM. The results show that the room temperature strength of the sand samples hardened by ultrafines is increased about 23% and the residual strength is reduced about 76% to the sand samples hardened by ester. In the ultrafines hardening process, the added quantity of sodium silicate is 3% and the added quantity of ultrafines is 25% of the added quantity of sodium silicate. The sodium silicate sand hardened by ultrafines is not sensitive to the module of the sodium silicate. In the hardening process, using high module sodium silicate can improve significantly the collapsibility and reclamation performance of the sand. The moisture resistance of the sodium silicate sand hardened by ultrafines is better than that of the sodium silicate sand hardened by ester.