共查询到18条相似文献,搜索用时 186 毫秒
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介绍了酯固化碱性酚醛自硬树脂在再生砂上应用存在的主要问题及原因,通过采用联合再生方式处理旧砂,降低再生砂灼烧减量和酸耗值,使用再生砂专用碱性酚醛自硬树脂,可以提高再生砂强度,减少铸件粘砂现象。 相似文献
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曹善堂 《中国铸造装备与技术》1984,(5)
一、前言树脂自硬砂砂型具有强度高、溃散性好、铸件表面光滑、尺寸精度高和生产效率高等优点,因此在国外已得到广泛的应用。最近十几年来,树脂自硬砂的旧砂再生技术也有了很大的发展。据报导,英国在1976年共有61套砂再生设备(干法53套,湿法5套,加热法3套),其中约70%用于再生呋喃树脂砂;美国和加拿大到1977年为止,共有化学粘结剂砂再生设备633套,其中65%是1971年以后安装的;日本两个铸造机械公司近年来销售的砂再生设备中,用于树脂自硬砂的超过50%以上。旧砂再生技术之所以得到迅速的发展,首先是因为树脂自硬砂要求采用质量高的砂子,新砂消耗量大,这就提高了型砂的费用,再加 相似文献
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A lot of mixed clay-resin waste sand from large-scale iron foundries is discharged every day; so mixed waste sand reclamation in low cost and high quality has a great realistic significance. In the study to investigate the possibility of reusing two types of waste foundry sands, resin bonded sand and clay bonded sand which came from a Chinese casting factory, a new low-cost reclamation method of the mixed foundry waste sand based on the wet-thermal composite reclamation was proposed. The waste resin bonded sand was first reclaimed by a thermal method and the waste clay bonded sand was reclaimed by a wet method. Then, hot thermal reclaimed sand and the dehydrated wet reclaimed sand were mixed in certain proportions so that the hot thermal reclaimed sand dried the wet reclaimed sand leaving some water. The thermal reclamation efficiency of the waste resin bonded sand was researched at different heat levels. The optimized wet reclamation process of the waste clay bonded sand was achieved by investigating the effects of wet reclamation times, sand-water ratio and pH value on the reclaimed sand characteristics. The composite reclamation cost also was calculated. The research results showed that the properties of the mixed reclaimed sand can satisfy the application requirements of foundries; in which the temperature of the thermal reclamation waste resin bonded sand needs to be about 800 oC, the number of cycles of wet reclamation waste clay bonded sand should reach four to five, the optimal sand-water ratio of wet reclamation is around 1:1.5, and the pH value should be adjusted by adding acid. The mass ratio of hot thermal reclaimed sand to dehydrated wet reclaimed sand is about 1:2.5, and the composite reclaimed sand cost is around 100 yuan RMB per ton. 相似文献
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分析了覆膜砂旧砂热法再生的影响因素。试验结果表明,采用热法再生砂制成的覆膜砂具有强度高、发气量低等优点,将其运用于实际生产可降低生产成本,具有良好的社会经济效益。 相似文献
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通过对酯硬化碱性酚醛树脂旧砂的模拟再生试验,分析了再生前后砂样的灼烧减量、发气量等性能的变化,以及对型砂强度的影响因素。结果表明:采用模拟再生工艺可使再生砂回收率达到95%左右;在再生砂中加入质量分数10%~20%的新砂,可明显提高再生砂的黏结强度,为更好运用酯硬化碱性酚醛树脂砂生产高强度钢种的铸件提供旧砂再生工艺方案。 相似文献
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微波水玻璃砂芯和砂型及其旧砂再生 总被引:2,自引:0,他引:2
研究了微波水玻璃砂的工艺性能、造型制芯、铸件浇注、旧砂再生及其再生砂性能。结果表明,微波水玻璃砂不仅水玻璃加入量少,而且强度高,溃散性接近树脂砂,旧砂易于再生。最后展望了微波水玻璃砂的应用前景。 相似文献
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水玻璃砂的化学-机械干法再生及应用 总被引:2,自引:1,他引:1
根据水玻璃砂再生回用理论,通过加入RCT改性剂和水溶性树脂对水玻璃砂进行化学改性,加以机械设备的软机械再生-通过砂块与砂粒之间的摩擦而去掉旧粘结膜,从而实现水玻璃砂的干法再生。获得的再生砂可直接用于面砂。 相似文献
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