物理法对蛭石膨胀特性及脆性的影响

Effects of Phsical Treatment on the Expansion Characteristics and Brittleness of Vermiculite

通过膨胀率和粉碎后-150μm粉末产率系统研究了高温法和微波法对蛭石膨胀性能及脆性的影响规律,采用X射线衍射及热重-差示扫描量热法分析蛭石热膨胀过程中物相变化规律,并对影响膨胀蛭石脆性指标的机理进行探讨。结果表明,蛭石在高温膨胀过程中,由于层间水的迅速失去,膨胀率逐渐增大,当蛭石失去结构水时,-150μm粉末产率迅速增加导致产品脆性性能下降,最终蛭石转变为镁橄榄石,膨胀率和粉末产率急剧下降;微波法对蛭石结构水无较大影响,产品不发脆。

Foucus on the effect of electric heating and microwave irradiation method on the expansion and brittleness performance of vermiculite. The expansion and screening experiment were introduced. The phase changes of vermiculite were studied with X-ray diffractometer（ XRD） and thermogravimetrydifferential scanning calorimetry（ TG-DSC）,and the mechanism of vermiculite brittleness was explored.The results indicated that the interlayer water of vermiculite was excluded rapidly and the expansion rate of vermiculite was gradually increased during the electric heating. The structure water of vermiculite was dehydrated while the brittleness performance of vermiculite dropped consequently and the yield of expanded vermiculite with particle size below 150 μm increased dramatically. The expansion ratio and the yield of expanded vermiculite with particle size below 150 μm decreased,and the vermiculite was converted into forsterite finally. The expended vermiculite prepared by microwave with better brittleness performance than that of electric heating. The result contributed to the existence of the structure water during microwave irradiation.