Patent ID: 9334549
Filing Date: 2016-05-10
CPC Classification: C22B

Claim Text:
1. A method for extracting rare-earth (RE) oxide constituents from a feedstock containing RE silicates and non-RE contaminants, wherein the feedstock comprises at least one of Yttrium (Y) or Ytterbium (Yb) in the form of at least one of RE 2 Si 2 O 7 (REDS) or RE 2 SiO 5 (REMS), the method comprising: leaching the REs from the feedstock into an acid to form an acid solution; performing an oxalate precipitation on the acid solution to form an RE oxalate hydrate; separating the RE oxalate hydrate from the acid solution; and heat treating the RE oxalate hydrate to form an RE oxide containing the RE elements extracted from the feedstock, wherein the leaching comprises treatment with hydrochloric (HCl) acid, resulting in a residue of substantially Silicon dioxide (SiO