Conventional crush-grind-CIL to produce gold-silver- doré
Nominal treatment rate
Current mine life
The Mt Rawdon gold deposit is a massive, volcaniclastic hosted, low grade gold deposit that exhibits excellent characteristics conducive to low cost mining and treatment. The surface extent of mineralisation greater than 0.7g/t gold formed an ovoid zone 400 metres x 280 metres in diameter on the southern flanks of the original Mt Rawdon. The gold mineralisation is closely associated with fine disseminated pyrite within the host rocks as well as more discrete sulphide veinlets. Gold grade generally increases as pyrite alteration and sulphide veining increases. The principal host volcaniclastic rocks dip moderately to the southwest, as does the orebody.
Mt Rawdon performed exceptionally well in FY13 with gold production of 106,089 ounces, an 11% increase compared to FY12 production of 95,403 ounces. The average operating cash cost (C1) of A$613 per ounce was significantly lower than FY12 cash cost (C1) of A$684 per ounce. Mine production is derived from a single open pit, utilising conventional drill and blast, load and haul methodologies. These functions are undertaken by separate contractors with management by Evolution staff. The operation is scheduled to continue until FY2023 at current estimates with a life-of-mine strip ratio of 2.2:1.
The processing plant consists of primary and secondary crushing, SAG and ball milling, followed by conventional cyanidation leaching. In FY13 a total of 3,329,000 tonnes were treated at an average grade of 1.08g/t gold and recovery rate of 92%.