MAGNETIC FLOTATION AND AGGREGATION PROCESS AND DEVICE FOR THE CONCENTRATION OF MAGNETIC IRON MINERALS

摘要

The invention relates to a novel device and process for enriching magnetic minerals (magnetite) by removing metal sulphides, silicates, phosphates and other unwanted particles, characterised by a device comprising a downflow pipe (mixer) and a separation column surrounded by Helmholtz coils. Pulp is fed into the mixer, in which air bubbles form in the presence of the pulp and bubble-particle collection processes are performed. The mixer discharges the pulp-bubble mixture into the separation column in a region that has a low magnetic field, less than 200 Gauss, which can be adjusted. Non-magnetic particles (gangue) are removed by the bubbles at the upper part of the column to form the tailings from the process, while magnetic particles sediment rapidly on the bottom of the column, from where they are removed to form the iron concentrate. As a result of the increase in the percentage of solids in the concentrate cone, most of the water that enters the device is discharged in the tailings, generating an upward flow of water which drags the gangue particles that were not captured by the bubbles. Using these mechanisms, the gangue is discharged in the tailings by two methods: flotation, and hydrodynamic drag. The magnetite forms aggregates of sufficient weight that they are not conveyed by the bubbles but sediment rapidly on the bottom of the column, allowing selective separation of magnetite and gangue.