Production of pelletizing concentrates from Zandrivierspoort magnetite / haematite ore by magnetic separation
P Muthaphuli
Kumba Iron Ore’s Zandrivierspoort (ZRP) magnetite-haematite project aims
to mine and beneficiate a magnetite resource with low contaminant levels
to produce from 1 Mt/a to 2.5 Mt/a product, which will be either a
concentrate, micro-pellets for direct reduction, or blast furnace pellets.
Anglo American Technical Solutions Research conducted a number of
piloting campaigns to validate the process design flow sheet, demonstrate
process performance, and to generate data for use as a design basis.
Secondary to this, the pilot plant was to produce approximately 7 t of
magnetite-haematite concentrate with low enough SiO2 to be used as
feedstock for pelletizing studies.
The pilot plant achieved 34.2% mass yield, at 69.0% Fe, 2.2% SiO2,
from an IsaMill grind of 80% -45 µm. This product quality will compare
favourably to other leading direct reduction (DR) pelletizing concentrates.
However, two-stage comminution to 80% -75 µm and beneficiation of ZRP
ore will produce a blast furnace (BF) quality pelletizing concentrate,
indicative quality being 67.6% Fe and 4% SiO2, at higher mass yields. An
economic evaluation between producing a DR and a BF pelletizing
concentrate will have to be conducted prior to finalizing the concentrate
production flow sheet.
Keywords: Magnetic separation, iron ore, magnetite, haematite.