Conventional crush-grind-CIP to produce gold-silver dore
Current mine life
The Pajingo mine's mineralisation is hosted in structurally controlled epithermal quartz veins within an andesite host rock. In general, veining strikes grid east with tensional jogs producing high grade pods trending grid east-north-east. The main mineralised veins in the Vera Nancy corridor plunge at about 20 degrees to grid east.
Most ore bodies comprise a main vein, which carries the bulk of the precious metals, and splay veins that can contain economic grades but usually only when close to the main vein. The mineralised structures can vary from less than 1 metre to 15 metres in width, but are generally 1 metre to 3 metres wide.
Underground mining is based on modified avoca and longhole open stoping methods with ore hauled to surface via decline. Open pit mining is by conventional drill and blast, load and haul methodology. Pajingo lifted gold production from 75,747 ounces in FY12 to 85,918 ounces in FY13, an increase of 13% and a doubling of gold production in less than two years under Evolution ownership. Cash operating costs (C1) for FY13 were A$807 per ounce. Total underground ore mined in FY13 was 331,000 tonnes at 6.19g/t gold. Open pit ore production in FY13 was 357,000 tonnes at a grade of 2.36g/t gold.
Ore is free milling and is treated on site by conventional crush-grind-CIP processing to produce gold-silver-dorè. A total of 611,000 tonnes were treated at an average grade of 4.57g/t gold and a 96% recovery rate for FY13. Plant throughput increased by around 25% compared to FY12 due to an increase in mill feed. The processing plant has a design capacity of 650,000 tonnes per annum.