Magnetic separation of materials
US4125191A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 7, 1976 |
| Grant date | Nov 14, 1978 |
| Priority date | — |
| Expiry date | Sep 7, 1996 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB03C1/02
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Fragments of ferromagnetic material, such as tin can pieces, are sorted by size on apparatus including an inverted conveyor that carries fragments that have been previously oriented with their longest axes placed in parallel directions past a line of magnets spaced progressively further apart in the direction of orientation of the fragments. The magnets attract the fragments strongly to the conveyor directly under the magnets, but progressively more weakly in those spaces between the magnets so that the shorter pieces separate gravitationally from the conveyor sooner than the longer pieces. Fragments having varying magnetic susceptibility, such as, for example, tin can pieces with and without attached normally round aluminum tops, are also separated according to their magnetic susceptibility by conveying the fragments beneath carefully spaced magnetic devices whereby the fragments of lower susceptibility drop from the conveyor sooner than those of higher susceptibility due to the weaker magnetic field between magnetic devices. The spacing between magnetic devices, for example, can be slightly greater than the diameter of an aluminum top in the case of the exemplary fragments.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.