Guyana Goldfields Advances Aurora Project
The proposed mine plan calls for production of 250,000 oz/y of gold over a 16- year mine life, first from open-pit and then from underground operations. The open-pit tonnage would total 17.9 million mt at an average grade of 2.8 g/mt, while the underground tonnage would total 18.1 million mt at an average grade of 4.5 g/mt.
The Aurora ore is mainly non-refractory sulphides, with a small portion of oxides (saprolite) near surface. The proposed flowsheet calls for SAG and ball-mill grinding, followed by gravity and carbon-in-pulp (CIP) circuits. Mill throughput is proposed at 8,000 mt/d.
Capital expenditures for the Aurora project are projected at $262 million for pre-production development of the openpit and surface operations, $21 million for surface equipment, $147 for underground development, $10 million for underground equipment, and $80 million for sustaining capital, including cost of closure. Operating costs are estimated at $364/oz.
The preliminary assessment assumes an open-pit production fleet of 15 Caterpillar 777 trucks, four Cat 992 loaders, and 6.5- in. down-the-hole drills. Underground access would be via a 4.5-m wide by 4.5- m high ramp at a negative gradient of 17% and a 5.8-m-dia, concrete-lined shaft to a depth of 1,400 m. The shaft would be equipped with a double-drum hoist and 12- mt skips with slung cages on both sides. Underground mining would be by sub-level open stoping, with typical stope dimensions of 20 m long, by 20 m wide, by 30 m high. Underground production equipment would include hydraulic two-boom jumbos, 5-m3 capacity LHDs, and 28-mt and 50-mt capacity trucks.
The Aurora project timeline includes two years for construction and development (2010-2012), start of open-pit operations in 2012, open-pit life of nine years, first underground production in 2015, and underground operations from 2015 to 2028.
Guyana Goldfields holds a 100% interest in the Aurora project, subject to a 5% royalty payable to and determined at the discretion of the Guyana Geology and Mines Commission. Guyana Goldfields submitted a preliminary environmental impact assessment for the project to the Guyanese Environmental Protection Agency in June 2009, and the company reports that the permitting process is proceeding well.