Verfahren zum Rückgewinnen von refraktären Komponenten aus Formmasken beim Giessen mit verlorener Giessform.

摘要

A highly efficient method for recovering Y2O3 from used investment casting shell molds containing Y2O3 is disclosed. The used mold materials are introduced into a dissolution reactor preferably consisting of a rotating vessel having an interior lining of acid and abrasion resistant material. An acid is combined with the materials in the reactor and agitated for a selected time period. Thereafter, the liquid remaining in the reactor is separated from the residual solids and removed. The liquid contains dissolved Y2O3 which is precipitated, preferably using oxalic acid to produce yttrium oxalate [Y2(C2O4)3.9H2O]. The Y2(C2O4)3 9H2O is ultimately removed from the solution and calcined to produce high purity Y2O3.