Method for recovering casting refractory compositions from investment casting shell molds
US4815516A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 4, 1988 |
| Grant date | Mar 28, 1989 |
| Priority date | — |
| Expiry date | Mar 4, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P10/20
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Y.sub.2 O.sub.3 is recovered from investment casting shell molds by introducing used mold materials 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 Y.sub.2 O.sub.3 which is precipitated, preferably using oxalic acid to produce yttrium oxalate [Y.sub.2 (C.sub.2 O.sub.4).sub.3.9H.sub.2 O]. The Y.sub.2 (C.sub.2 O.sub.4).sub.3.9H.sub.2 O is ultimately removed from the solution and calcined to produce high purity Y.sub.2 O.sub.3.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.