One of the main reagent costs for HPAL plants is sulphuric acid , however if you input sulphide ore it contributes sulphuric acid in the autoclave. There is also usually a benefit for the treatment of sulphide ore in HPAL plants that recoveries tend to be higher and the finished products can be sold to battery manufacturers.
Now lets circle back to AML, the initial flowsheet proposed was to use Low pressure POX to leach the concentrates. The cobalt rich pyrite concentrate could relatively easily be a fed into the HPAL increasing the cobalt units and increasing sulphuric acid (reducing HPAL costs).
If everything works as planned, Walford Creek ore just had to be trucked to NCZ, they could produce the different concentrates. Copper, Zinc and Lead concentrate can be exported to customers. The pyrite concentrate can be shipped to Goro for treatment.
Now obviously tying all this up and getting all the pieces in place (especially taking on Goro) is a risky proposition which is why they want NCZ To shoulder the majority of the risk but there are some very interesting synergies and possibly what IGO has in mind. If you don’t have to build a plant to treat Walford creek ore the economics the economics would be very attractive for developing Walford Creek. If it reduces the overall costs of Goro then it is a win/win. This probably means that IGO can provide an attractive bid for AML/Walford creek and still have plenty of upside for themselves.
AML Price at posting:
9.3¢ Sentiment: None Disclosure: Held