Effluent treatment in a process for producing chlorine dioxide from chloric acid
US5354435A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 31, 1992 |
| Grant date | Oct 11, 1994 |
| Priority date | — |
| Expiry date | Dec 31, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S423/13
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The novel process of the invention produces chlorine dioxide by feeding an aqueous solution of chloric acid to a chlorine dioxide generator. The aqueous solution of chloric acid is reacted with a reducing agent in the chlorine dioxide generator to produce chlorine dioxide and a spent chloric acid solution containing metallic impurities. A portion of the spent chloric acid solution containing metallic impurities is reacted with a basic compound selected from the group consisting of alkali metal hydroxides, and alkali metal carbonates in a neutralizing zone to form a precipitate of the metallic impurities and an alkali metal chlorate solution. The precipitate of the metallic impurities is separated from the alkali metal chlorate solution and the alkali metal chlorate solution fed to an ion exchange compartment of an electrolytic cell having an anode compartment, a cathode compartment, and at least one ion exchange compartment between the anode compartment and the cathode compartment. Electrolysis of an anolyte in the anode compartment generates hydrogen ions which pass through a cation exchange membrane into the ion exchange compartment to displace alkali metal ions and produce an aq…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.