Perth, May 16, 2008 AEST (ABN Newswire) - Pilbara iron ore developer Aurox Resources Limited (ASX: AXO)(PINK: AUOXF) is pleased to announce it is progressing studies into the beneficiation and sales of phosphate from its Balla Balla project.
Potential processing and sale of a phosphate concentrate could further enhance the already strong Balla Balla project economics, with the phosphate-rich zone currently scheduled for removal as waste during magnetite mining.
The phosphate is contained in the hanging-wall waste rock located immediately above the Balla Balla magnetite ore (Figure 1) and has a tenor comparable to known economic phosphate rock operations (Table 1).
Apatite is the rock phosphate mineral used in the production of phosphoric acid and fertiliser. The sales price of phosphate concentrate has increased from $US50/tonne to $US400/tonne in the past 12 months.
From the Balla Balla assay and geological information currently available, the phosphate mineralisation appears to extend 10 to 15 metres immediately above the titanomagnetite ore into the hanging-wall waste rock. The apatite bearing material displays grades of between 3% and 7% P2O5 over this distance. The target size of the phosphate mineralisation over the 18 kilometre strike of the deposit is estimated to be well over 100 million tonnes.
The project is located within 100km of a major fertilizer producer, which has previously expressed interest in purchasing phosphate rock concentrate from Balla Balla. Further discussions with fertilizer and chemical producers are planned once the current technical and financial review on the Balla Balla phosphate has been completed.
Table 1 - Comparable Phosphate Rock Deposits-------------------------------------------------Site Name Location Tonnage(Mt) P2O5(%) Status-------------------------------------------------Phalaborwa RSA 2210 7 OperatingSiilinjarvi Finland 465 4 OperatingJacupiranga Brazil 100 5 OperatingKovdor Russia 700 7 OperatingSept- iles Quebec 108 6 Proposed-------------------------------------------------Source: USGS Open File Report 2002
In September 2005 Aurox reported that preliminary beneficiation tests on apatite-bearing hangingwall rocks had commenced. A composite sample from two core-holes was compiled, which assayed 4.1% P2O5. Bulk magnetic separation of a 25 kg charge ground to P80 of 75 microns at 1200 gauss and 8000 gauss gave a non magnetic fraction containing 5.3% P2O5. (Note: gauss is a unit of magnetic induction)
The non-magnetic fraction accounted for 61.5% of the mass, representing an 84% recovery of phosphate to the non-magnetics. The non-magnetic fraction was subject to rougher and cleaner flotation to recover apatite. The cleaner flotation concentrate that assayed 30.5% P2O5 was recovered. The phosphate recovery to this stream is approximately 80%, giving an overall phosphate recovery of approximately 67%.
The cleaner concentrate produced from the limited testwork thus far is encouraging in terms of phosphate content. However, further tests will be necessary to reject contaminants such as silica and iron oxides to provide a saleable product. Diagnostic mineralogy has been completed and the apatite grains show a lack of inclusions, and are instead covered by fine dust. The main gangue components appear to be silicates.
The company will continue to keep the market informed as the Balla Balla studies advance.
Aurox is well advanced in the development of Balla Balla, having completed a Bankable Feasibility Study for six million tonnes of magnetite iron ore production annually. The Company has in place two 15 year sales contracts for a total of 6 million tonnes per annum increasing to 10 million tonnes per annum concentrate production in year 5 with major Chinese Steel Companies.
Balla Balla is based on a large homogenous magnetite ore body, which will be developed as one of the lowest cost magnetite operations in Australia. The project also has significant titanium potential, and is located near major ports, gas and grid power with main highway access.
The new Balla Balla Bankable Feasibility Study demonstrates strong project economics with magnetite iron ore shipments to China scheduled to commence in the second half of 2010.
Contact
Charles Schaus
Managing Director
Tel: +61-8-9382-4477
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