Peak Resources: maiden JORC Resource of 170Mt tonnes at 2.24% rare earth oxide from Ngualla

 

 

It has not been lost on some investors that Ngualla is a company maker, with the project already drawing comparisons to Lynas Corporations' (ASX: LYC) Mt Weld, being rare earth enrichment in the deeply weathered regolith profile of a large carbonatite.

 

 

From the Southern Rare Earth and South West Alluvial Zones the resource is 170 million tonnes at 2.24% rare earth oxides, for 3.8 million tonnes of contained rare earth oxides (1.0% lower grade cut-off).

 

 

Using a 3.0% lower grade cut-off, the total resource includes a higher grade near surface zone of; 40 million tonnes at 4.07% rare earth oxides for 1.6 million tonnes of contained rare earth oxides.

 

 

Richard Beazley, managing director, commented on the positive news: 

 

 

“What makes this discovery very attractive is the significant grades that make Ngualla stand apart from most rare earth deposits. Having these high tonnages and grades places Ngualla amongst the top rare earth resources outside of China.

 

 

“This resource puts Peak in a dominant position from which to develop the asset into an operating mine with its strengths defined to date by the significant tonnes and grade, very low thorium and uranium levels and outcropping bulk style geometry centred around a hill lending itself for very low strip ratios in mining."

 

 

Where the story gets even more interesting for Peak is that the resource is from drilling between the surface and 150 metres in depth - and still remains open in many directions - providing the enticing notion of potential upgrades in the future.

 

 

The next step for the company will be a new drilling campaign, which will allow the commencement of Scoping Studies in the June 2012 quarter.

 

 

Beazley added, "Additionally, metallurgical test work will continue and further bulk material is scheduled to be supplied from additional diamond drilling to support the ongoing metallurgical program later in the year.

 

 

"Peak will also be moving forward with a scoping study to integrate the current defined maiden resource and metallurgical understanding with other key aspects such as marketing, logistics, supply and mining to assess the economic potential of numerous development pathways for the project over the coming year."

 

 

The structure of Ngualla 

 

 

The Ngualla rare earth deposit can be divided into two geographic and geological areas, the Southern Rare Earth Zone located in the centre of the carbonatite around Ngualla Hill, and the South West Alluvial Zone.

 

 

Southern Rare Earth Zone: A 1 kilometre by 1 kilometre area in the low magnetic central core of the Ngualla Carbonatite. Rare earth mineralisation occurs from surface and is enriched in the weathered zone of the carbonatite, varying from a few metres to 140 metres vertical depth.

 

 

Fresh rock mineralisation extends to the current drill depth of 155 metres from surface. Mineralisation in the Southern Rare Earth Zone remains open to the north, south and with depth with a high likelihood that further drilling would increase the size of the deposit.

 

 

The bulk of the Mineral Resource at Ngualla is contained within the Southern Rare Earth Zone and most of the highest grade component occurs near surface within the weathered zone.

 

 

Positive signs as metallurgical test work leaches 88% of rare earths

 

 

Preliminary metallurgical testwork has recently delivered some positive outcomes for Peak, with the highlight non–optimised initial acid leach test work on a composite sample of weathered mineralisation which leached 88% of rare earths, with further leach test work now having been prioritised.

 

 

This work is to evaluate the possibility of a relatively simple processing route to produce a high grade rare earth concentrate for this higher grade, near surface portion of the Ngualla rare earth mineralisation.

 

 

Peak said that simple wet table characterisation of primary fresh rock rare earth mineralisation produces positive beneficiation results in preliminary sighter tests.

 

 

Mineralogical studies at a glance

 

 

Mineralogical studies have shown that bastnasite and synchysite are the main rare earth minerals and occur within a barite – iron oxide hydroxide lithology in the weathered zone and a carbonate rich lithology with barite in fresh carbonatite.

 

 

Alumina is negligible and there are no clay minerals. Uranium and thorium levels are very low at 17ppm and 37ppm average respectively within +1% REO mineralisation in the Southern Rare Earth Zone. The rare earth carbonates are predominantly liberated, with grain sizes between 10 and 120 microns.

 

 

Beneficiation of primary mineralisation

 

 

Initial beneficiation studies on a bulk diamond core sample of fresh rock rare earth mineralisation from the Southern Rare Earth Zone returned encouraging upgrades of from wet table test work.

 

 

This initial basic baseline test work succeeded in concentrating 84% of the head feed mineralisation, with a grade of 1.69% REO, 290% (almost 3 x’s) to 4.87% REO.

 

 

The concentrate is contained within just 34% of the mass of the original feed material (an alternative presentation of these initial results is that 66% of the original mass is able to be discarded for the loss of just 16% of the mineralisation).

 

 

Although this single stage preliminary beneficiation characterisation work has not immediately produced a commercial grade concentrate, it has demonstrated the potential for simple gravity separation to form an important component of a multi – part processing stream for this important second style of rare earth mineralisation at Ngualla.