Fabrication and chemical durability of hot-pressed Na-bearing fluorapatite-type Ca8Sm1Na1(PO4)(6)F-2 ceramic for immobilization of trivalent minor actinide
Fabrication and chemical durability of hot-pressed Na-bearing fluorapatite-type Ca8Sm1Na1(PO4)(6)F-2 ceramic for immobilization of trivalent minor actinide
复制标题
热压含钠氟磷灰石型Ca8Sm1Na1(PO4)(6)F-2固定三价次锕系陶瓷的制备及化学稳定性
DOI：
10.1016/j.jnucmat.2018.05.017
复制
发表时间：
2018
影响因子：
3.1
通讯作者：
Peng Shuming
中科院分区：
文献类型：
--
作者：
Gao Xiaonan;Huang Yi;Teng Yuancheng;Yan Minhao;Zhang Haibin;Tuo Xianguo;Peng Shuming
采用热单轴压（HUP）烧结工艺成功制备了氟磷灰石型Ca8Sm1Na1(PO4) 6f2陶瓷。研究了烧结温度和保温时间对陶瓷相对密度和维氏硬度的影响。考察了浸出前后Ca8Sm1Na1(PO4) 6f2陶瓷的表面微观结构、失重率和表面组成。研究了浸出温度和pH值对陶瓷化学耐久性的影响。结果表明：在1100 ℃下，HUP烧结2 h，陶瓷的相对密度达到99.46%，维氏硬度达到3.704 GPa；在pH = 3的培养基中，在90 °C条件下，Sm、Ca、P、Na和F的失重率最大（0.578%），标准化元素浸出率最高。介质（pH = 3）中陶瓷表面腐蚀明显，存在大量的晶间和粒内孔隙。小重量损失率(0.003% - -0.008%)和Ca的归一化元素浸出率低(7.44 × 10−3 g m-2d-1 - 8.22 × 10−4 g m-2d-1)和Sm(9.11 × 10−6 g m-2d-1 - 1.07 × 10−6 g m-2d-1)是在媒体上(pH = 7、9和11),表明Ca8Sm1Na1 (PO4) 6 f2ceramic具有很高的化学稳定性在中性和碱性媒体90年 °C。
The fluorapatite-type Ca8Sm1Na1(PO4)6F2ceramic was successfully fabricated by hot uniaxial pressing (HUP) sintering process. The effects of sintering temperature and holding time on the relative density and Vickers hardness of the ceramic were investigated. The surface microstructure, weight loss rate and surface composition of Ca8Sm1Na1(PO4)6F2ceramic before and after the leaching experiment were examined. The influences of leaching temperature and pH value on the chemical durability of the ceramic were also studied. The results showed that the ceramic sintered by HUP at 1100 °C for 2 h obtained the highest relative density (99.46%) and maximum Vickers hardness (3.704 GPa). The largest weight loss rate (0.578%) and the highest normalized elemental leaching rates of Sm, Ca, P, Na and F were obtained in the media (pH = 3) at 90 °C. The surface of ceramic in the media (pH = 3) appeared obvious corrosion with plenty of intergranular and intragranular pores. The small weight loss rates (0.003%–0.008%) and the low normalized elemental leaching rates of Ca (7.44 × 10−3g m-2d-1- 8.22 × 10−4g m-2d-1) and Sm (9.11 × 10−6g m-2d-1- 1.07 × 10−6g m-2d-1) were acquired in the media (pH = 7, 9 and 11), indicating that the Ca8Sm1Na1(PO4)6F2ceramic possessed high chemical durability in the neutral and alkaline media at 90 °C.