Garnet mineralisation at Garnet Hills represents a 5 km long hard rock skarn deposit occurring in the high grade metamorphic Tickalara Formation, 280 km south of the East Kimberley port of Wyndham and adjacent to the all-weather bitumen Great Northern Highway. The haul road passes through the Garnet Hills Mining Lease and represents a convenient 9 km link to the Great Northern Highway (Figure 1).
A non-JORQ compliant geological garnet resource of 390,000 to 575,000 tonnes tonnes grading 31.2% andradite garnet has been established for the northern portion of Garnet Hills tenement based on RC drilling and surface geological mapping (refer Appendix 1).
The garnet resource delineated to date represents approximately 10% of the estimated size of the overall skarn deposit within the granted Mining Lease. An adjacent EL – E80/4159 also contains garnet skarn mineralization and will potentially add to the hard rock garnet inventory and 20 plus years of industrial garnet production from the area.
The garnet skarn is associated with subordinate accessory skarn minerals including epidote, quartz, diopside, calcite, actinolite, wollastonite and trace sulphides. Importantly, there are no deleterious trace elements associated with the garnet skarn making the garnet products environmentally friendly. Processing will also be free of any added contaminants such as chlorine.
Metallurgy - Recent ore-sorting studies involving state of the art Steinert RGB ore-sorting technology has achieved >90% garnet concentrates from crushed, run of mine (ROM) garnet skarn (refer Appendix 2). This has major implications for reducing benefication costs and initially producing direct – shipping garnet concentrates.
Beneficiation studies conducted both in Australia and China have shown that the garnet can be separated from the gangue minerals (quartz and epidote) by simple magnetic separation and can easily achieve a jet-cutting 80 mesh (~180 µm) product with <2% Total Free Quartz (TFQ) representing the benchmark safety standard (refer Appendix 3).