Patent ID: 6042748
Filing Date: 2000-03-28
Classification: C09K,Y02W

Abstract:
A method for regenerating a fluorescent material wherein an extra fluorescent material produced in a coating step for the phosphor screen of an image receiving tube is recovered and regenerated, comprising the steps of:(a) a chemical washing step for decomposing impurities contained in a recovered phosphor slurry with the use of a hypochlorite and a periodate to remove the impurities;(b) a carbon removing step for adding aqueous ammonia to the phosphor slurry and agitating the admixture, then, allowing the same to stand thereby floating carbon in a supernatant liquid, and removing the carbon contained in the supernatant liquid;(c) an acid washing step for washing the phosphor slurry with hydrochloric acid or nitric acid; and(d) a heat treating step for heat-treating the phosphor slurry at a temperature of from 350 to 600.degree. C. after filtering and drying the phosphor slurry at need.