非常温作用下水玻璃旧砂的干法再生性研究  

Study on Dry Reclaimability of Used Sodium Silicate Sand at Abnormal Temperature

作　　者：王继娜[1] 樊自田[1] 张辉明[1] 

机构地区：[1]华中科技大学材料成形与模具技术国家重点实验室,湖北武汉430074

出　　处：《铸造》2009年第1期67-70,共4页Foundry

基　　金：国家自然科学基金资助项目(50575085)

摘　　要：干法再生水玻璃旧砂工艺,设备简单、成本低、二次污染少,但再生砂的脱膜率低、质量不高。如果再生前将水玻璃旧砂进行非常温处理(加热或冰冻)可以提高再生脱膜率,改善再生砂的性能。本文测试了普通干法再生、"加热-干法"再生和"冰冻-干法"再生的脱膜率,对比了几种循环再生砂的再粘结强度、可使用时间和残留强度。试验结果表明:普通干法再生的脱膜率为5%～10%,320℃"加热-干法"再生的脱膜率为20%～25%,-40℃"冰冻-干法"再生的脱膜率为35%～40%;而320℃"加热-干法"再生砂的再粘结强度和可使用时间最大,-40℃"冰冻-干法"再生砂的残留强度最低、溃散性最好。这一研究结果为改进水玻璃旧砂再生工艺、改善水玻璃再生砂性能等提供了有意义的新方法。Dry reclamation of used sodium silicate sands has the advantages of simple reclamation equipment, low cost and less second pollution. However, the stripping rate is low, and the quality of reclaimed sands is poor. The treatment for used sodium silicate sands at abnormal temperature （ heating or freezing ） could enhance the stripping rate and improve the quality of reclaimed sands. In this study, the stripping rates of different processes were tested, such as common dry reclamation, ＂heating-dry＂ reclamation and ＂freezing-dry＂ reclamation. Furthermore, the rebinding strength, bench life and the residual strength of reclaimed sands with different processes were compared with each other. The results indicated that the stripping rate of common dry reclamation was 5%-10%, and that of ＂heating-dry＂ reclamation at 320 ℃ was 20%-25%, the ＂freezing-dry＂ reclamation at -40℃ achieved 35%-40%; the rebinding strength and bench life of ＂heating-dry＂ reclaimed sands at 320℃ was the biggest, and the residual strength of ＂freezing-dry＂ reclaimed sands at -40℃ was the lowest, hence its collapsibility was the best. The results provided a significant new method for the improvement of the reclamation technology for used sodium silicate sands and the quality of reclaimed sands.

关 键 词：水玻璃旧砂 非常温作用 “加热.干法”再生 “冰冻-干法”再生 

分 类 号：TG221[金属学及工艺—铸造]