酯硬化水玻璃再生砂循环使用后的性能变化及应对策略

Performances Change and Answer Strategies of the Sodium Silicate Reclaimed Sand Hardened with Ester After Recurrence Using

分析了酯硬化水玻璃砂多次再生使用后,其Na2O含量较大升高、溃散性显著下降、生产厚大铸型(芯)时硬透性变差并出现蠕变现象的原因,探讨了再生砂性能变化后的应对策略。认为:研究开发适于干法再生水玻璃砂的改性水玻璃、对再生砂实施表面处理、对旧砂进行高脱膜率的再生等,应是解决酯硬化水玻璃砂多次再生使用后溃散性恶化问题的主要措施;而控制再生砂的含水量、适当增加有机酯的加入量、CO2气体补充硬化等,是增加型(芯)硬透性和克服蠕变现象的主要方法。

The causes of performances change of the sodium silicate reclaimed sand hardened with ester after recurrence using many time, including Na2O content increasing, collapsibility falling, thorough hardening ability dropping and so on, are analyzed, and the answer strategies are also discussed. The authors consider that main measures would be taken as developing the new modified sodium silicate binder suiting for the reclaimed sand, actualizing surface disposing to the reclaimed sand and increasing the film escaped rate of reclaiming machine in order to overcome deteriorated collapsibility of the reclaimed sand, and that main ways of increasing the thorough hardening ability and overcoming the slow distortion should be controlling the containing moisture of reclaimed sand, adding ester quantity and using CO2 gas complementary rigidification.