The tests proved that 50% of the waste rock can be removed from the ore after initial crushing using the XRT sorter for less than C$2 per tonne. That means almost 50% less material that needs further grinding and flotation. The lesser mill throughput will save an estimated 30% in capital costs, 25% in processing costs, and 7% of overall operating costs. Process water and power consumption in the mill will also be cut by as much as 50%.
Less rock and water going through the mill also means fewer tailings. Osisko estimates that only 13% of all extracted ore will need storing at the existing QR mill facility as filtered tailings.
Osisko says that ore grading higher than 4.0 g/t gold will go directly to flotation and lower grades will be passed through the sorting process before further treatment. Gold recovery from flotation of the higher grade ore is 98.3%.
Further testing of the ore sorting technology is planned.
(This article first appeared in the Canadian Mining Journal)
