It is reported that Legacy Iron Ore has delivered to the market another set of very positive results with drilling having now consistently intersected the thick, shallowly dipping magnetite bearing BIF unit over an extensive 10 kilometre long strike.
All of the assays have now been received for the phase two 5000 metre reverse drilling campaign, but the good news for Legacy Iron doesn't stop there.
DTR testing has again displayed high level weight recoveries and concentrate grades with low silica and negligible phosphorus and sulphur.
Ms Sharon Heng MD commented on the very positive metallurgical results that “These drilling and metallurgical test work results are outstanding as they not only point to low mining costs but also to low processing costs producing a premium grade product which has the real potential to underpin extremely attractive project financials.”
He said that "With NMDC confirmed support and we look forward to rapidly developing the project this year with on-going drill programs, testwork and studies.”
The metallurgical test work results highlight a relatively soft magnetite with low Bond Work Index, high weight recovery and coarse grind for premium concentrate, low power costs.
1. DTR testing of phase two drilling
DTR testing from phase 2 drilling has produced very similar results to that of previous drilling. Using a relatively coarse grind size of P80/50 55 microns, DTR testing shows achievable grades of 69% to 70% iron, with high weight recoveries of circa 45%.
Importantly the silica contents at this relatively coarse grind remain low averaging 3% to 4% with very low sulphur and phosphorus.
2. Low grinding costs
Legacy Iron added that comprehensive testing on diamond core samples by Ammtec has provided a Bond Work Index of 11kWh per tonne. This is relatively soft for magnetite BIF mineralisation.
In comparison, most WA magnetite BIF projects have a Bond Work Index of circa 18kWh per tonne to 20 kWh per tonne.
3. Low Operating Costs
Where the story becomes even more interesting for Legacy Iron is the combination of being able to produce a quality concentrate at a relatively coarse grind and the soft nature of the mineralisation has a very significant positive economic impact for a mining project at Mt Bevan.
A major OPEX cost in magnetite projects is power consumption. Preliminary energy calculations based on the grind and bond work index indicate power requirements of only 12 kWh per tonne very low compared to that of about 30 kWh per tonne for typical WA magnetite projects.
4. JORC pending end of January
SRK Consulting is currently working on a JORC Inferred Resource for the whole Western BIF target with results forecast to be delivered at the end of this month.
5. Phase three infill drilling set to launch
A new drilling program known as phase three is set to commence at the end of February and will cover 7000 metres with the main objective of converting part of the JORC Resource to the higher confidence Indicated category from Inferred.
(Sourced from www.proactiveinvestors.com.au)
