Study of solidification performance of phosphate cement to 90Sr
磷酸盐水泥对90 Sr固化性能的研究

Using dead-burned magnesia (Containing >95% MgO) and phosphate as raw materials, the phosphate cement with strontium has been prepared. The phase compositions, microstructure of as-prepared samples have been investigated by XRD and SEM, anti-leaching performance test has also been done with GB 7023-86(Long-term leach testing of solidified radioactive waste forms). Experimental results show that addition of Sr reduces the compressive strength of phosphate cement; with more Sr addition, the greater strength loss will be found. Phosphate cement has good anti-leaching performance, the leaching rate and accumulated leaching scores are only 4.57 10-5cm/d, 7.39 10-3cm in 28 day. Compared with the samples prepared by different phosphate as raw materials, the compressive strength and leaching properties of samples with ammonium dihydrogen phosphate or potassium dihydrogen phosphate as raw material, is obviously superior to those of samples with diammonium hydrogen phosphate as raw materials.