maks phosphate rock, page-6

ive never seen anything substantial

ive tried the only reference i know is in the independent geologist report below




Rio Tinto Technical Services carried out beneficiation tests to determine the potential to upgrade the Wonarah ore. These tests were limited to physical upgrading by washing and screening and while reducing the deleterious elements failed to give a major increase in grade. Previous studies employing

SIXflotation failed to give satisfactory recoveries when lifting the grade to 30% P2O5 which is considered to be optimum for the DAP process.
The reduced estimated size of the resource and the inability to upgrade the mineralisation economically was considered to seriously lower the Wonarah project’s potential. RTE carried out a reverse economic study indicating that the project was then NPV negative and withdrew from the joint venture in late 2002.
Exploration by RTE during 2001-02 also included field work on the outcropping Upper Gum Ridge Formation phosphorite beds at the Arruwurra prospect which lies 16km southwest of the Wonarah deposit. This area is shown on Figure 15 and requires more detailed investigation. The Wonarah Beds outcrop in the north central area, but are generally highly weathered and covered by stabilised Cainozoic aeolian sand sheets and longitudinal dunes. Silcrete and ferricrete duricrust has developed beneath the sand cover and can outcrop as low rises. Calcrete and black soil overlies dolostone in the south central area. At the Arruwurra outcrop sampling indicated the phosphorite is high grade but of unknown extent. It outcrops over a strike of about 2km with grades up to 30% P2O5 with less than 5% Al2O3 + Fe2O3.