"Magnetite is the highest grade commercial Iron ore mineral, so it's blended with other ores (Haematite for example) to increase the average iron content(Fe)"
Sorry but I'm a little confused here, I am under the impression that Magnatite is a lower grade mineral 25 - 30% Fe
and Hematite the richer grade(63% as in SDL's case) then you have Itabrite around 30% as well.
Cheers