If CCC's Penumbra project can reach 490 Rand FOB, IKW's project should be around the same or less.
Reasons:
CCC is underground mining, in general, mining cost roughly the same as open pit at 5:1 stripping ratio. IKW is open pit at 4.6:1 stripping ratio.
Rail distance to Richards bay: CCC around 500km, IKW less than 400km.