| 摘要 |
An efficient method is proposed for decolorizing a rare earth oxysulfide, which is usually slightly colored in grey as prepared by the sulfiding reaction of a rare earth oxide with hydrogen sulfide, by removing sulfur impurity. The method comprises two steps of heat treatmentof which the first step is conducted in air at 450 DEG to 550 DEG C. for 2 to 5 hours and the second step is conducted in an inert gas, e.g., argon, at 800 DEG to 950 DEG C. for 2 to 5 hours.
|
