人造岩石固化体SrCeTi_2O_7的合成与性能研究  

Synthesis and Property of SrCeTi_2O_7 Synroc for Immobilization of High Level Radioactive Waste

作　　者：邹秋林[1] 赖振宇[1] 卢忠远[1] 

机构地区：[1]西南科技大学四川省非金属复合与功能材料重点实验室-省部共建国家重点实验室培育基地,四川绵阳621010

出　　处：《原子能科学技术》2012年第11期1307-1312,共6页Atomic Energy Science and Technology

基　　金：国家自然科学基金资助项目(10976023);西南科技大学先进建筑材料四川省重点实验室开放基金资助项目(07XZJ002);西南科技大学国防重点学科实验室开放基金资助项目(08zxnp05);西南科技大学研究生创新基金资助项目(12ycjj08)

摘　　要：采用88Sr模拟放射性核素90Sr,Ce4+模拟四价锕系放射性核素。以分析纯SrCO3、CeO2和TiO2为主要原料,通过高温固相反应制备SrCeTi2O7人造岩石固化体。对固化体的烧成工艺、物理性能、晶体结构及微观形貌进行研究,并对固化体的热稳定性及抗浸出性能进行探讨。结果表明,选择配方n(SrCO3)∶n(CeO2)∶n(TiO2)=1∶1∶2,在1 450℃下保温5h可合成结构致密、晶型发育完整的SrCeTi2O7人造岩石固化体;Dicvol程序指标化结果表明,该固化体化合物属四方晶系,晶胞参数为a=0.387 33(4)nm,c=0.388 07(5)nm;SrCeTi2O7人造岩石固化体具有良好的热稳定性,经高达800℃热处理后样品仍保持原有物相不变;PCT-B粉末浸泡法测试结果表明,SrCeTi2O7人造岩石固化体具有较好的抗浸出性能,浸泡周期28d时Sr、Ce和Ti的浸出率分别为3.51×10-4、8.23×10-8和2.02×10-7 g/(m2.d)。Simulating radionuclide 90Sr with 88Sr and tetravalent actinides radionuclides with Ce4+, using analytical SrCO3, CeO2 and TiO2 as raw materials, the SrCeTi2O7 synroc was synthesized through a high temperature solid-state method. The synthesis technology, physical properties, crystal structure and microstructure of SrCeTi2O7 synroc were researched. The thermal stability and leaching performance were also investigated. The results show that when selecting formulation as n(SrCO3):n(CeO2):n(TiO2)=1:1:2, sintering at 1450°C with holding time 5 h can synthesize SrCeTi2O7 synroc with dense structure and well crystallized. Indexing results show that SrCeTi2O7 synroc crystallizes as a tetragonal structure with the lattice parameters are a=0.38733(4) nm, c=0.38807(5) nm. The SrCeTi2O7 synroc has excellent thermal stability, and it maintains the SrCeTi2O7 phase after 800°C heat treatment. Product consistency test shows SrCeTi2O7 synroc has good leaching performance, and the leaching rate of Sr, Ce and Ti are 3.51×10-4, 8.23×10-8 and 2.02×10-7 g/(m2&middotd) in 28 days, respectively.

关 键 词：SrCeTi2O7 人造岩石 固化 合成 高放废物 

分 类 号：TL941[核科学技术—辐射防护及环境保护]