a good manetite resource could grade up to 41% fe but a good hemetite resource grading 68% is a dying breed.
most current hemetite resource are now about 58% and require added cost benificating to turn them into a saleable product.
also most hemetite resources have a very high stripping ratio compred with a good magnetite deposit so the operating cost of mineing could be much cheaper for magnetite!
also for magnetite, we have pelletizing costs to consider but these costs are offset by a premium price paid for pellets.
also now in 2008 we live in a different paradigm from 30 years ago. the steel industry is in a much bigger economic footprint and is more inclined to invest in a better quality product like a magnetite based steel production facility.
