Method for treating, spent dryfilm stripping and developing solutions
US4857206A · kind A · utility
12Cited by
4References
2Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Nov 2, 1987 |
| Grant date | Aug 15, 1989 |
| Priority date | — |
| Expiry date | Nov 2, 2007 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC02F2101/32
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A method of treating spent dryfilm stripper and developer solutions by mixing the spent solutions with a solution of aluminum sulfate and borax in controlled amounts causing a reaction which results in a slurry of a non-sticky, benign precipitate in a supernatant liquid. The supernatant liquid contains the dissolved heavy metals. The non-sticky precipitate does not interfere with the ph measurement which indicates when the reaction is complete, and the benign precipitate can be fillered out for disposal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.