Mining Operations – Eloise Copper Mine & Gordon Sirdar
Eloise Copper Mine
The Eloise deposit was discovered by BHP in 1987. The deposit was then acquired by Amalg Resources from BHP in 1995. The portal was commenced in 1995 with the first ore mined in April 1996. In February 2003 Amalg Resources merged with Breakaway Resources to form the new company Breakaway Resources Limited. In May 2004 Barminco Pty Ltd ( now FMR Investments Pty Ltd) purchased the mine from Breakaway Resources and operated the mine and mill until it was placed under a care and maintenance programme in November 2008 owing to the fall in commodity prices. The Board of Directors at FMR Investments has recently approved the recommencement of mining operations at the mine. The mine is currently operational.
Geology & Mining
The Eloise copper deposit primarily comprises two main sub-parallel ore zones about 15 to 20 metres apart that strike north-south and dip steeply to the east. The two ore zones occur over a strike length of about 650 metres and have been drilled to depths in excess of 1,200 metres.
The mine is accessed via a 1:7 decline driven at 5.0 W x 5.5 H. The decline is 10kms in length and at depth of 1200 metres. Mine levels are typically driven at 25m vertical spacing to access the orebody. The underground workings are ventilated via two downcast shafts and one primary exhaust shaft.
Eloise is located in an area of high geothermal gradient with ground temperature of 55 degrees C at 1,100 metre depth. To enable mining to continue, intake air passes through a 2.8MW chiller plant located on the surface before transferring underground via two downcast shafts.
Eloise Copper Mine operates a conventional floatation circuit to produce a high grade copper concentrate with gold and silver credits. The mill is capable of sustaining a rate of 600,000 tonnes per annum. The plant operates a two stage crushing facility capable of producing a -16mm product at 100-120 tph. This is comprised of a primary jaw crusher and apron feeder operating in closed circuit with a secondary cone crusher.
Communition is via a 2 stage crushing circuit grinding to a typical p80 of 75 micron. The floatation circuit comprises rougher and scavenger floatation cells and a bank of cleaner and recleaner cells.
Thickening and filtration is handled via a 9.0 metre diameter Larox Supaflo thickener with the underflow running at 65 to 80 % solids. The underflow goes to 1.8 metre diameter American disc filters producing filter cake with moisture content of about 13%. The concentrate is sun dried to about 8 to 9% moisture content ready for transport and shipment.
The Gordon Sirdar Project comprises tenements located within the North East Coolgardie mineral field 55 kms northeast of Kalgoorlie-Boulder.
The mine sequence comprises unmineralised porphyry to the east. Gold mineralization is associated with a highly silicified carbonated, fuchsitic and pyritic lode system within the Gordon shear zone. Current efforts are focused on mining high grade gold zones beneath the existing Gordon Sirdar open cut and defining high grade zones to the north- west where the Leslie Lode was recently discovered.
Historical production from the Gordon Sirdar underground workings produced 45,842t averaging 11.27 g/t (16,610 ounces) between 1899 and 1950. Between June 1999 and May 2000 91,243t@ 6.26g/t for 18,341 ounces were mined utilizing open cut methods.
The Board of FMR Investments has recently approved the commencement of open-pit mining operations. This operation started early October 2010 and will continue for about 10 months. It is anticipated that mechanised underground mining operations will then start with further diamond drilling activities scheduled to commence at the same time to better define the resources at the siteRead On