| Patent application number | Description | Published |
|---|
| 20090324487 | Method for preparing iron oxides - Highly pure iron oxides are prepared by reaction of metallic iron, in the form of microspheroidal particles or of scraps or cuttings, with an agitated aqueous solution of a mono- or polycarboxylic acid with a pKa of 0.5 to 6 relative to the first carboxyl and capable of decomposing, by heating in air at 200 to 350° C., to carbon dioxide and water, using 0.03 to 1.5 moles of acid per g-atoms of iron, a water/iron weight ration of 1 to 20, and by oxidation of the ferrous carboxilate to ferric salt, with an agent selected from oxygen, mixtures containing oxygen, hydrogen peroxide, organic peroxides and hydroperoxides. | 12-31-2009 |
| 20110251054 | METHOD FOR PREPARING IRON OXIDES - Highly pure iron oxides are prepared by reaction of metallic iron, in the form of microspheroidal particles or of scraps or cuttings, with an agitated aqueous solution of a mono- or polycarboxylic acid with a pKa of 0.5 to 6 relative to the first carboxyl and capable of decomposing, by heating in air at 200 to 350° C., to carbon dioxide and water, using 0.03 to 1.5 moles of acid per g-atoms of iron, a water/iron weight ration of 1 to 20, and by oxidation of the ferrous carboxilate to ferric salt, with an agent selected from oxygen, mixtures containing oxygen, hydrogen peroxide, organic peroxides and hydroperoxides. | 10-13-2011 |
