Treatment of waste sulfuric acid by gypsum precipitation in a titanium dioxide process
US5298169A · kind A · utility
0Cited by
3References
7Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 21, 1992 |
| Grant date | Mar 29, 1994 |
| Priority date | — |
| Expiry date | Aug 21, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC02F2101/20
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
Disclosed is a process for treating waste sulfuric acid generated from a process for producing titanium dioxide pigment by treating titanium slag with sulfuric acid. The waste acid is treated in a first step with a calcium-containing material to produce a gypsum suspension which is filtered and from which a filtrate is recovered. The filtrate is treated in a second step with a calcium-containing substance and clarification solids from the treatment of the titanium slag with sulfuric acid. A precipitate is produced in this second step which is subsequently filtered. The precipitate is suitable for disposal in a landfill.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.