Recovery of sodium hydroxide and aluminum hydroxide from etching waste
US5049233A · kind A · utility
13Cited by
10References
23Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jul 6, 1990 |
| Grant date | Sep 17, 1991 |
| Priority date | — |
| Expiry date | Jul 6, 2010 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23F1/46
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A method for the recovery and recycling of sodium hydroxide from the waste solution of aluminum etching operations. The method utilizes a dialysis membrane column or stack to initially remove sodium hydroxide from the waste solution and return it to the etch tank base solution sufficiently concentrated to carry on the basic etching operation. The method permits the recovery of salable quantities of aluminum hydroxide.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.