350km east of Perth, Western Australia, Australia
Westonia, Merredin and all communities within 100km of the Edna May operations site
Year commenced operations
3 historical mining phases:
Style of mineralisation
Felsic intrusion hosted stockwork with high grade reef development
Predominantly gold, with silver and tungsten
Measured, Indicated and Inferred Resources (at 31 Dec 2016)
19.4Mt @ 1.36g/t gold for 848koz gold
Ore Reserves (as at 31 Dec 2016)
8.22Mt @ 1.61g/t gold for 426koz gold
FY2010A 10,222 ounces
FY2011A 65,592 ounces
FY2012A 73,264 ounces
FY2013A 86,216 ounces
FY2014A 80,165 ounces
FY2015A 98,766 ounces
FY2016A 71,028 ounces
Conventional crush-grind-CIL to produce gold dore
Nominal treatment rate
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 amphibolite.
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 remaining life-of-mine strip ratio of 2.3:1. This allows the mine to employ a single mining fleet 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.
Underground development commenced in June 2016 with contractors starting ground preparation for the portal and surface water reticulation pipework. Portal development and installation of genset and power reticulation is planned in the September FY17 quarter.
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%.
Edna May fact sheet – updated May 2017