Processing titaniferous ore to titanium dioxide pigment
US6375923B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 7, 2000 |
| Grant date | Apr 23, 2002 |
| Priority date | — |
| Expiry date | Feb 7, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P10/20
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A hydrometallurgical process is provided for producing pigment grade TiO2 from titaniferous mineral ores, and in particular from ilmenite ore. The ore is leached with a hydrochloric acid, preferably a recycled solution at high hydrochloric acid concentration, to form a leachate containing titanium and iron chloride and a residue. The leachate may be filtered to separate the leachate from the residue. The leachate is cooled to a temperature sufficient to form crystals of FeCl2, which are separated from the leachate. The leachate may be subjected to a reduction step to reduce Fe+3 to Fe+2, before crystallizing. The leachate is subjected to a first solvent extraction to form a pregnant strip solution containing titanium and ferric ions and a raffinate containing ferrous ions. This strip solution is subjected to a second solvent extraction to form a second strip solution containing ferric ions and a raffinate containing titanium ions. The first strip solution may be subjected to an oxidization step before the second solvent extraction. The second raffinate containing titanium ions is hydrolyzed. The hydrolysis can be by water addition or spray hydrolysis. Iron chloride is converted to …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.