Effects of sintering process, pH and temperature on chemical durability of Ce0.5Pr0.5PO4 ceramics

Chemical durability and leaching mechanism of Ce0.5Eu0.5PO4 ceramics: Effects of temperature and pH values

“…Whatever the leachates considered, the release of Eu is higher than that of Ce after 42 days. It is inconsistent with the previous studies [46], which the R Pr were similar to the R Ce . Considering that the ionic radius of Ce 3+ is bigger than that of Eu 3+ , it may lead that the ionic concentrations of leachates are not consistent with the stoichiometric formula (Ce 0.5 Eu 0.5 PO 4 ).…”

“…After 42 days (see Table 2), the R Ce and R Eu in Ce 0.5 Eu 0.5 PO 4 ceramics sintered by HPS are 0.29 × 10 -12 m·d -1 and 2.13 × 10 -12 m·d -1 , respectively. Compared with HPS samples leached in pH = 9 leachate, the relative high elemental release rate is observed at the linear evolution of the leach rates, which is in agreement with that reported in the literature [46].…”

“…The leach rates of Ce (R Ce ) and Eu (R Eu ) of the samples in deionised water at regular intervals are presented inTable 1. Since crystal defects of unwashed materials leading to a higher increase of elemental leaching in initial period[46][47], it can be observed Figs. 3 that the LR Ce and LR Eu in all the samples quickly decrease in the first 7 days and remain almost unchanged after 21 days.…”

Effect of sintering technique on mechanical property and chemical durability of Ce0.5Pr0.5PO4 ceramics

“…These results indicate that the sintering parameter 1500 ºC for 4 h is a turning point for sample's densification. In addition, compare with NPS sample sintered at 1500 ºC for 4 h, HPS sample sintered at 1150 ºC for 2 h possess smaller average grain size and higher relative density [43,44]. Fig.…”

New insights into phosphate based materials for the immobilisation of actinides

“…Sintering at higher temperature was observed to result in the decomposition of the phosphate group [147]. Hot-pressing methods allow for lowering the sintering temperature by about 250-300°C at 30 MPa, yielding pellets with 98 % relative density [143,[148][149][150][151][152]. Du et al [153][154][155] achieved the same density (98 %) of La-monazite after 3 min of sintering at 1350°C (heating rate 100°C · min −1 ) at a pressure of 40 MPa using Spark Plasma Sintering (SPS).…”