非常温作用下水玻璃旧砂的干法再生性研究.pdfVIP

学兔兔 Jan．2oo9 铸 造 VOI．58 NO．1 FOUNDRY · 67 · 非常温作用下水玻璃旧砂的干法再生性研究 王继娜，樊自田，张辉明 (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) 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”冰冻一干法”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℃ “加热一干法”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，-4O℃ “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。 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 中图分类号：TG221 文献标识码：A 文章编号：1001—4977(2009)01—0067—04 Study on Dry ReclaimabUity of Used Sodium Silicate Sand at Abnormal Tem perature WANG Ji-na，FAN Zi-tian，ZHANG Hui—ming fState Key Laboratory of Material Processing and Die＆Mould Technology Huazhong University of Science and Technology，Wuhan 430074，Hubei，China) Abstract：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 IOW，and the quality of reclaimed sands iS poor．The treatment for used sodium silicate sands at abnormaf 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 Iife and the residuaI 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％-1 O％．and that