Record Display for the EPA National Library CatalogRECORD NUMBER: 4 OF 4
|Main Title||Regeneration of Caustic Soda Etch Solutions for Aluminum.|
|Author||Brown, C. J. ;|
|CORP Author||Environmental Protection Agency, Washington, DC.|
|Additional Subjects||Materials recovery ; Aluminum hydroxides ; Precipitation ; Chemical etching ; Reprints ; Alkalies ; Centrifuging ; Concentration(Composition) ; Solutions ; Byproducts ; Recycling ; SIC 3479 ; Solution regeneration|
The process utilizes precipitation and centrifugation to remove Al(OH)3 from caustic aluminum solutions. When etching aluminum in a solution of caustic soda prior to anodizing, sodium aluminate (NaAl02) increases in concentration in the caustic until a rock-like precipitate of Al(OH)3 drops out of solution. By precipitating Al(OH)3 in a separate crystallization tank without the use of sequestering agents, one obtains a potentially salable byproduct (Al(OH)3) and reduces caustic consumption by recycling recovered caustic.