Filo Mining’s Filo del Sol project outline has been detailed in an independent Technical Report, released on December 18. The epithermal copper-gold-silver deposit is located on the Chile/Argentina border, some 140 km southeast of the city of Copiapó, Chile.
The study states that the project is amenable to open pit mining techniques. To determine an appropriate
mining approach for this multi-metal, multi-zone deposit, the project team conducted an extensive strategic mine planning exercise. Scenarios, consisting of combinations of processing and mining strategies were assessed both qualitatively and quantitatively. The outcome was to adopt a three-
phase open pit that is mined at a rate sufficient to supply 50,000 t/d of feed to multiple heap leach processing facilities (a permanent cyanide leach, a permanent acid leach, and an on/off acid leach). The on/off acid heap leach facility (HLF) will have nine distinct cells. The cells are constructed adjacent to each other in a long row, allowing sequential processing of each cell. The HLF has been sized using an average stacked process feed density of 1.5 t/m and a heap height of 10 m.
The heaps will be constructed using conveyor stacking systems. The permanent heap conveyor stacking systems will include the following components:
– “Ramp” portable transfer conveyors, each approximately 36 m in length for conveying crushed material up ramps
– “Grasshopper” portable transfer conveyors, each approximately 36 m in length for conveying crushed material across relatively flat areas
– A 36 m horizontal “Index Feed Conveyor” that transfers crushed material from the grasshopper conveyors to a “Horizontal Feed Conveyor”
– A moveable 38 m “Horizontal Index Conveyor” that transfers crushed material to the radial stacker
– A 41 m “Radial Stacking Conveyor” capable of powered height adjustment, slewing and stacking to a height of 10 m
The grasshopper and ramp conveyors will transport the crushed material from the stockpile reclaim conveyors for the permanent heaps onto and across the pad to the stacking conveyors. The stacking conveyors allow the radial stacker to place crushed material in 10 m lifts with minimal downtime. The radial stacker and horizontal feed conveyor together are capable of moving while slewing and stacking ore in an arc. The radial stacker can retreat approximately the length of a grasshopper conveyor.
Open pit mining is to be conducted with standard mining equipment, including blast hole drills,
two 22m3 hydraulic shovels, two 20 m3 front-end loaders, and 20 136 t rear-dump haul trucks – all supported by dozers, graders, water trucks and ancillary equipment. The maximum combined mining rate of waste, process feed, and on-off pad re-handle is 47 Mt per annum. Complete extraction of the mineable resource is to take 13 years, including one year of pre-production mining.
