Patent ID: 8524176

Claim:
A method for recovery of a rare earth constituent from a phosphor, the method comprising: leaching a rare earth constituent from a phosphor to form a rare earth leachate solution; adjusting the rare earth leachate solution to a pH of about 2, and then precipitating the rare earth constituent from the rare earth leachate solution as one or more rare earth oxalates; and converting the one or more rare earth oxalates to one or more rare earth oxides; wherein the rare earth constituent comprises compounds comprising a rare earth element selected from the group consisting of La, Ce, Eu, Tb, Y and combinations thereof; and wherein the leaching comprises a first stage of leaching Eu and Y-comprising compounds from the phosphor by dilute H 2 SO 4 to form a Eu and Y leachate, while La, Ce and Tb-comprising compounds from the phosphor are retained in an un-leached residue.