To add to the confusion, GMC's project metrics state 0.341 tonne of FeSi and 0.48 tonne of burnt lime per 1 tonne of FeMn alloy. I'm still at a loss as to why no cost has been allocated against these two items either - which would otherwise account for over 30% of processing costs - unless they are byproducts reintroduced into the process. The inputs for producing FeSi and burnt lime are sand, iron ore, coal and limestone.
I understand the 0.43t FeSi (and 0.713t burnt lime) figure comes from the Strachan report, but he appears to be describing the typical smelting process for FeMn alloy.
In the recent * interview, Hamish explains that GMC will not be producing typical FeMn alloy. He also quotes a much high sale price for their final product.
“We’ll be explicitly producing ultra-low carbon ferromanganese alloy. There isn’t much out there in the market because not many people can make it.”
This means Gulf Manganese will be able to sell its ferromanganese product at a premium to low-carbon ferromanganese, which currently fetches around $US2000 per tonne.
“We would expect quite quickly to get a premium on top of that,” Mr Bohannan said.
For arguments sake, let's allow a cost for FeSi and burnt lime (missing from GMC's project metrics) and plug in Strachan's (US?)$0.09/kWh, 0.43t FeSi and 0.713t burnt lime, as well as Hamish's minimum US$2000/t expected sale price:
The result is an even more viable project.