Method for direct reduction and upgrading of fine-grained refractory and earthy iron ores and slags
US6048382A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 6, 1998 |
| Grant date | Apr 11, 2000 |
| Priority date | — |
| Expiry date | Apr 6, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P10/134
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A method of upgrading relatively rich, fine-grained earthy hematite iron ores is provided. The iron ore, after suitable preparation, is reduced using a solid state reduction technique. As a result of the reduction process, the iron grains undergo size enhancement while the nonmetallic oxides are unreduced and remain as refractory oxide gangue. After completion of the reduction process, the enlarged malleable metallic iron grains are crushed in such a way as to cause the iron grains to fuse together, forming large, flat iron flakes. In order to achieve maximum flake size, the crushing system applies a relatively gradual pressing force rather than a rapid, impact type of force. As the large flakes are formed, the iron grains are liberated from the refractory oxide grains resulting in an increase in density. The crushing system causes non-iron oxide bonds to be broken, resulting in the formation of residual refractory particles generally with a grain size of less than 0.05 millimeters. The shape, size, density, and ferromagnetic differences between the iron flakes and the nonmetallic oxides are used to separate the iron from the nonmetallics. A variety of different separation techniqu…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.