Al2O3对独居石玻璃陶瓷固化体的影响

Effect of Al2O3 on Monazite Glass-ceramic Wasteform

  • 摘要: 本文研究了Al2O3掺量对独居石玻璃陶瓷固化体结构和化学稳定性的影响。用傅里叶变换红外光谱(FTIR)和X射线衍射(XRD)方法表征样品结构,用溶解速率法和全谱直读等离子体发射光谱(ICP-OES)分别测定样品在浸出液中浸泡后的失重速率及各元素的浸出浓度,以研究固化体的化学稳定性。研究结果表明:当Al2O3掺量为4%(摩尔分数)时,在980 ℃下保温3 h得到的独居石玻璃陶瓷固化体具有较高的化学稳定性,浸泡14 d时其质量浸出率最低,约为8.1 ng/(cm2•min),其中Ce、La元素在浸出液中均未检出;固化体的主晶相为独居石,结构中含有大量稳定的正磷酸基团PO43-和少量的焦磷酸基团P2O74-,不存在偏磷酸基团PO3-

     

    Abstract: The effects of monazite glass-ceramic wasteforms containing different Al2O3 contents on their structures and properties were investigated. The structure of the glass-ceramic wasteforms was analyzed by Fourier transform infrared (FTIR) and X-radiation diffraction (XRD). The chemical stability of monazite glass-ceramic wasteforms was measured by dissolution rate and inductively coupled plasma optical emission spectrometry (ICP-OES) method. The results show that the chemical stability of monazite glass ceramic wasteforms with 4% (mole fraction) Al2O3 and made at 980 ℃ for 3 h is optimal. The 14 d leaching rate of monazite glass-ceramic wasteforms is about 8.1 ng/(cm2•min), which is the lowest in all the samples. The main crystalline phase of the as prepared glass-ceramic wasteforms is monazite. There are a large number of PO43- groups, a small number of P2O74- groups, and no PO3- groups in the wasteforms.

     

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