烧绿石及碱硬锰矿型矿物晶体化学及其核废料固化基材研究进展

摘要

Pyrochlore- and hollandite-type minerals were extensively investigated as the nuclear waste-forms, showing the unique properties on thermal and chemical stabilities and irradiation resistance. In the past decade, our group methodically studied the crystal structure and chemistry of pyrochlore- and holladnite-type natural minerals and their synthesized compounds. According to X-ray diffraction analysis of fourteen synthesized rare-earth pyrochlore (Ree2B2O7, B=Ti, Zr), both Ree2Ti2O7 and Ree2Zr2O7 show obvious crystal structure variable. The study of hollandite crystal structure indicates that contents of cationA (A0-2B8O16,A=Na, K, Sr, Ba, etc.,B=Ti, Fe, Mn, Al, etc.) in the tunnel and parameters regarding anisotropy usually cause one-dimension incommensurate modulation structure along with c direction. This paper summarized our recent results on their structure and chemistry, and reviewed the research and development of their application in nuclear waste immobilization.%研究表明烧绿石和碱硬锰矿在固化核废料方面具有良好的性能。近年来我们对烧绿石型和碱硬锰矿型天然矿物以及系列人工合成矿物的晶体结构及晶体化学进行了系统详细的研究。通过人工合成14种镧系稀土的Ti和Zr的Ree2B2O7系列氧化物的X射线衍射实验，发现其Ti的Ree2Ti2O7系列氧化物和Zr的Ree2Zr2O7系列氧化物都出现了明显的晶变现象。晶体结构研究显示碱硬锰矿型结构矿物中 A 类阳离子在孔道中的含量变化及各向异性参数的变化导致了该型结构往往存在沿 c轴方向的一维非公度调制结构。同时对烧绿石和碱硬锰矿在固化核废料方面的研究现状及进展进行了综述。