Using a combination of wet high gradient magnetic separation and a specialised flotation regime, it has been successfully demonstrated that 38% of the plant feed can be rejected prior to acid leaching for only 5% loss in the rare earth content.
The beneficiation process enhances the economics of the Ngualla operation and will be included in the Scoping Study, which is on track for completion by mid-December 2012.
Richard Beazley, managing director, commented: "This achievement is a very important breakthrough by Peak's Technical Team.
"We have always said we intend to be a low cost producer and the physical upgrade will contribute significantly to achieving this."
Highlighting the significance and scale of the breakthrough at Ngualla, the project already hosts a resource of 170 million tonnes at 2.24% REO - ranking it as the fifth largest rare earth deposit in the world outside of China.
The total resource includes a higher grade, near surface zone of 40 million tonnes at 4.07% REO for 1.6 million tonnes of contained REO.
Beazley added, "We have a high grade deposit, the mineralisation is shallow, has excellent metallurgical characteristics, and with this physical upgrade and the forthcoming Scoping Study we believe Peak is very well placed to continue hitting its milestones."
Maintaining momentum - Peak has already started work to further optimise this beneficiation process for input into Feasibility Studies due to commence in early 2013.
Ngualla is a bulk deposit which is largely outcropping and has the lowest uranium and thorium levels of any major rare earth deposit in the world.
Technical Report from Peak
Beneficiation tests were completed on a composite sample of mineralised intervals from diamond drill hole NDD007 within the highly weathered portion of the SREZ targeted for first production.
Detailed mineralogy undertaken using QEMSCAN techniques on coarse crushed and screened feed samples identify native mineral sizes and associations.
Results show an intimate association between iron oxide and rare earth minerals (hematite and bastnaesite). The gangue minerals of barite and silica generally do not contain rare earth inclusions and have discrete grain boundaries with bastnaesite, indicating that grinding will separate these minerals.
The ground feed was subjected to wet magnetic separation WHGMS at increasing field strengths. The resulting non-magnetic stream was subjected to a program of flotation test work directed at recovering rare earth minerals whilst rejecting barite and silica.
This process proved effective at rejecting the non-magnetic barite and silica fraction, which comprises 38% of the original feed but only 5% of the rare earths.
Peak had over $8.3 million in cash at the end of September 2012.
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