中文摘要：

以分析纯CaCO3、TiO2、SiO2和CeO2为原料,铈作为铀的模拟元素,采用高温固相反应,合成了包容铈的榍石基人造岩石固化体。通过XRD、SEM、EDX等手段对固化体物相组成及微区成分进行了分析,参照国家标准＂放射性废物固化体长期浸出试验＂（GB 7023—86）及美国PCT（Product Consistency Test）法对固化体进行了抗浸出性能试验。结果表明,在1 300℃下保温2 h可以制备出以榍石为主要晶相的人造岩石固化体,在不引入任何电价补偿离子时,Ce4＋在榍石晶体内Ca2＋位置的固溶度小于0.05个结构单位。榍石对Ce具有良好的固溶效果,当固化体中Ce的荷载量高达13.47%时,MCC-1静态浸出法测得Ce的90 d浸出率和累积浸出分数低至0.15×10-8cm/d和0.90×10-6cm,PCT粉末浸泡法测得Ce的7 d归一化浸出率仅为3.11×10-7g/（m2.d）。这一结果为榍石基人造岩石应用于固化放射性核素铀提供了理论依据。

英文摘要：

Using analytical CaCO3,TiO2 and SiO2 as raw materials,simulating uranium with cerium,the sphene synroc doped with cerium has been synthesized via a high temperature solid-phase reaction.The phase composition,microstructure and chemical contents have been investigated by XRD,SEM and EDX.Anti-leaching performance test has also been done with GB 7023—86,radioactive waste solidified body long-term leaching experiment and the Product Consistency Test.Experimental results show that the optimum synthesis temperature of sphene synroc is 1 300 ℃.Cerium ions can replace the position of calcium ions partly to form replacement type crystallology Ca1-2xCexTiSiO5,calcium position can load cerium less than 5% without any electrovalence compensation ion.While the synroc solidification loads as high as 13.47% weight of cerium,the leach rate and accumulated leaching scores of cerium measured by MCC-1 are only 0.15×10-8 cm/d,0.90×10-6 cm in 90 days,and 7 days＇ normalized leaching rate of cerium measured by PCT is just 3.11×10-7g/（m2·d）,which indicates that the sphene solidification has an excellent chemical durability.The results provide a theory basis for sphene applied in solidifying radionuclide uranium.