Low Temperature Sulfurization of Nd2O3 by Mechanochemical Method with CS2

For the recovery of nuclear materials from the spent nuclear fuel by the sulfide process, fission products such as rare-earths are selectively sulfurized by CS2 at temperatures below 500 °C. However, sulfurization at lower temperatures would be favorable from the safety handling of CS2. In this paper, low temperature sulfurization of neodymiumu oxide Nd2O3 by mechanochemical method in the presence of CS2 was studied. When Nd2O3 powder was milled with CS2 by planetary mill in argon atmosphere followed by heatreatment in Ar, the broaden peaks for Nd2O2S phase were found by XRD analysis. These peaks for Nd2O2S became sharpened by the heat treatment at temperatures 500 — 600 °C in argon atmosphere. The relative intensity ratio of Nd2O2S peaks to Nd2O3 peaks increased with increasing milling time as well as the increasing CS2 amount . Finally, the experimental results were in good agreement with those of thermodynamic consideration.