Treatment of effluents
US4360508A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 12, 1981 |
| Grant date | Nov 23, 1982 |
| Priority date | — |
| Expiry date | Mar 12, 2001 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC10K1/128
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Soluble thiosulphates present in aqueous redox systems comprising at least one salt of an anthraquinone di-sulphonic acid and at least one water soluble compound of metal having at least two stable oxidation states, for example a vanadate, are converted to sulphates by introducing oleum or sulphuric acid into the lower half of a vessel containing said thiosulphate containing redox solution, wherein the sulphuric acid has a concentration of from 10-98% w/w H.sub.2 SO.sub.4 and the amount of said sulphuric acid is such that the gram molecular weight ratio of sulphuric acid to thiosulphate is from 1:2 to 1:3, and thereafter separating the sulphate formed for example by using a solubility lowering technique. The process is carried out at ambient temperature and at a temperature of from 70.degree. C. up to the boiling temperature of the acidic mixture.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.