Were it that simple. Chinese mills have massive sintering...

Were it that simple. Chinese mills have massive sintering capacity that is fed by fines. The real question is: to what chemistry will the chinese mill industry lean when buying fines. You might assume the fines with the highest Fe content would be best, but you'd be wrong. While Fe content is one driver, the others are the deleterious element content (P, Al, Mn, Ca, Mg, Si), the sizing, and the value in use (VIU). Counter intuitively, the VIU is quite high for low grade (58% Fe) goethitic/limonitic pisolite ores because they produce great sinter with less energy, even though they have an apparent low Fe content (which increases as chemically bound H2O is driven off in the sintering process).

Some people push a future flight to magnetite concentrate because of its very high Fe content (68 to just under 7o% Fe). I would tend to agree philosophically. In practice, there are road blocks, the obvious one being that magnetite concentrate takes a helluva lot more energy to produce so is, theoretically just as, if not more polluting than fines. The key here is being able to "export" that pollution by importing magnetite concentrate from other countries.

The biggest untapped magnetite resources sit in SA, at the moment. The SA govt would be over the moon to divert its scarce electricity to magnetite production and away from the voting public - NOT!