The Project is located near the northern end of the Westonia Greenstone Belt, in the Southern Cross Province of Western Australia's Archaean Yilgarn Craton. The Westonia Greenstone Belt comprises a series of outliers of predominantly amphibolite-grade metamorphic rocks extending approximately 100km WNW from near Edwards Find, south of Southern Cross. The remainder of the terrane comprises granitic rocks and their metamorphosed equivalents.
The Edna May gold mineralisation consists of high-grade reef structures and associated stockwork veining hosted within three en-echelon tonalitic gneiss intrusions (Edna May, Greenfinch and Golden Point). The deposits are bound to the north and south by an ultramafic ampbibolite.
Open pit mining is by conventional drill and blast, load and haul method. A bulk mining approach has been adopted to the extraction of remnant high-grade reef structures and associated stockwork mineralisation with a life-of-mine strip ratio of 1.9:1. This allows the mine to employ a single mining fleet (owner operated) for most of the mine life. The open pit is being mined in four stages and is carried out on 10 metre benches and 2.5 metre flitches.
The process plant was purchased and transported from the Big Bell mine site to the Edna May site in 2007 and consists of a 2.0MW SAG mill and a 3.7MW Ball Mill along with other components necessary to provide a steady-state capacity of 2.6 million tonnes per annum.
The process plant consists of a conventional carbon in leach (CIL) process and SABC FF (SAG mill Ball mill pebble Crusher Feed Forward) circuit. The ore is metallurgically consistent with a typical metallurgical recovery of approximately 92%. Adjustments to the SAG mill lifters and liners will be made in FY14 to improve plant throughput, a bottleneck identified by the secondary crushing trials carried out during FY13.