Poseidon Nickel is taking the shovel to its nickel-rich tailings
This is exactly what the company has done, defining a resource of 675,000 tonnes grading 0.92% nickel and 683 parts per million cobalt, or a contained resource of 6,200t of nickel and 460t of cobalt, for its Silver Swans Tailings.
Metallurgical testwork on four composites selected achieved 48% recovery to a rougher flotation concentrate, with excellent repeatability in the results between the composites tested.
Notably, detailed mineralogy confirmed that nickel and iron sulphides reported to the concentrates while rejecting the majority of the magnesium oxide.
Poseidon said the results support the co-processing of the tailings with ore from the Black Swan disseminated open pit to increase the iron-to-magnesium oxide ratio, which improves product marketability.
Black Swan has 179,000t of resources in the Black Swan open pit, and additional stockpiles.
Detailed testwork is underway to optimise the blend ratio with appropriate proportions of the Silver Swan and Golden Swan massive sulphides.
These results will support a bankable feasibility study on restarting the Black Swan concentrator, at a production rate of 1.1 million tonnes per annum.
“The Silver Swan Tailings are a low cost, high Fe:MgO ratio ore feed for our “Fill The Mill” strategy,” managing director Peter Harold said.
“Combining the Silver Swan tails with the Black Swan disseminated ore feed significantly improves the saleability of the Black Swan concentrate product, and will assist with our discussions with potential off-takers as we progress toward a production restart.”
Silver Swan had produced 137,500t of nickel before it was placed on care and maintenance in 2009.
The decline remains accessible to the bottom of the mine and it is estimated to still host 16,000t of contained nickel.