Process for making goethite
US5641470A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 17, 1995 |
| Grant date | Jun 24, 1997 |
| Priority date | — |
| Expiry date | Jul 17, 2015 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2006/42
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
This invention provides a method of producing goethite particles comprising the steps of a) reacting, in aqueous solution, less than a stoichiometric amount of an alkali compound with an iron (II) salt to form a precipitated complex intermediate, b) oxidizing iron (II) in the complex intermediate to iron (III) at an average rate less than 10 g iron(III)/l/hr to form goethite seed particles until 20 to 70% of iron (II) in the precipitated complex intermediate has been converted to iron (III), and c) after 20 to 70% of iron (II) in the precipitated complex intermediate has been convened to iron (III), increasing the average oxidation rate to greater than 10 g iron(III)/l/hr.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.