Recycling of Cristobalite Powder in Casting Mould

Cristobalite SiO2 can be obtained from the fused silica ceramic waste of ploysilicon plant, due to the phase conversion of fused silica to cristobalite during the process of polysilicon ingot. Cristobalite powder materials with high purity are manufactured by milling the discarded waste above. Thermal expansion rate of the cristobalite and gypsum bonding moulds were studied, which show that the thermal expansion of the cristobalite phase transition could effectively compensate for the shrinkage of the gypsum at the temperature between 200 ℃ and 400 ℃. Casting experiments with copper alloy show that the cristobalite can improve the thermal performance of moulds for precise casting of jewelry.

一种玻璃窑用锆英石捣打料的研制与应用

为了降低锆英石捣打料的成本,提高施工现场的施工效率,提高锆英石捣打料的质量,以锆英石砖、锆英石砂为骨料,锆英石粉、锆英石微粉、再生电熔锆刚玉粉为细粉,研究了工业磷酸(85%)、硅溶胶(40%)两种不同结合剂作用下电熔锆刚玉粉加入量的试验。结果表明:添加5%再生电熔锆刚玉粉,用硅溶胶(浓度40%)作为结合剂的锆英石捣打料,养护时间短、显气孔率低、强度高,且具有良好的施工性能。在进行的工业试验中,使用超过4年均保持良好,能满足玻璃熔窑池底使用寿命及施工的要求,效果较好。