Method for treating cyanide waste liquid
US7253332B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Nov 7, 2002 |
| Grant date | Aug 7, 2007 |
| Priority date | — |
| Expiry date | Nov 7, 2022 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC02F2209/06
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A highly reliable detoxifying method of the cyano matters is provided. The waste-liquor, which contains at least one of free cyano material, a cyano complex and a reducing compound exhibiting volatility in alkaline aqueous solution, is heated under an alkaline condition to a temperature range, which lies within a range of from room temperature to the boiling point, and which includes a high temperature range of 80° C. or more, followed by holding the temperature; oxidation-reduction potential of the waste liquor is measured from the room temperature; and, hypochlorite is intermittently or continuously added to the waste liquor from the room temperature, until the oxidation-reduction of the hypochlorite is detected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.