Annual Report for ML 27244 Wonarah Mineral Lease for the period ending 17 February 2015

Abstract

ML 27244 forms part of the Wonarah Phosphate Project (along with EL 24607, EL 29840, EL 29841 and EL 29849), and is located approximately 240 km east-southeast of Tennant Creek. Minemakers Australia Pty Ltd is seeking to develop a large sedimentary phosphate deposit within the Georgina Basin. The project area has two principal areas of exploration focus; Main Zone and Arruwurra. The geology of the Main Zone comprises basement granite of Palaeoproterozoic age, unconformably overlain by basalt of the Helen Springs Volcanics. The volcanics are unconformably overlain by dolomitic rocks of the Thorntonia Limestone equivalent in part. The overlying phosphate-bearing Upper Gum Ridge Formation is divided locally into five main units; the Transitional Phosphorite, the Transition Sediments, the Chert Breccia Phosphorite, the Mudstone Phosphorite (main phosphate bearing unit) and the Convolute Mudstone. The Wonarah Formation overlies the Upper Gum Ridge Formation and consists of mudstone, siltstone and sandstone. The geology of Arruwurra is essentially similar with some minor differences. The Mineral Resource estimation for both Main Zone and Arruwurra is 842 Mt at 18.1% P2O5 (10% P2O5 % cut-off). The resource lies mostly within ML 27244 but extends onto adjacent Minemakers' tenements. During the reporting year, test work on high pressure grinding rolls (HPGR) was completed and initial test work indicated that HPGR may be useful in the comminution of Wonarah phosphate rock with critical parameters such as specific force and specific comminution energies within the desired ranges. The products of these tests were then subjected to the previously established, standardised attrition regime for Wonarah ore. The sized and assayed products of the attrition regime indicated improved Al2O3 rejection. These data were analysed to determine an algorithm that could be used to predict the distribution of products from HPGR based on the P2O5 and Al2O3 content of any feed. Analyses point to Al2O3 rejection above 90-92%, with corresponding P2O5 recovery of 82-87%. A second round of HPGL testing will be undertaken once the viability of the IHP technology has been satisfactorily validated. This work will include validating the theoretical Al2O3 rejection and P2O5 recoveries for other samples.