Yes, noticed the Co in some of my research today but I don't know more yet. Will find out more about mineralogy eg magnetite association with the nickel sulphides over coming weeks.
Initial thoughts are that it's a physical, not chemical bond as MMG said "The plant has the capacity to treat nickel sulphides locked in magnetite, through a magnetic separator, regrind mill and retreat flotation cells"
Quite a few good papers out there on Avebury for the geology/engineering inclined. Anyway, time to have a little pre-celebratory drink in anticipation of the creditors being glad to get a 100% return and handing MYL the keys.
Worth repeating also that the initial plant design was...."The conventional processing plant was designed with capacity to process 900,000 tonnes of ore to produce approximately 8,500 tonnes of nickel per annum in a nickel concentrate grading around 20%" at US$23,000 per tonne that's a lot of cash flow!