pretty quiet here today, page-6

Earlydays, the real reason that people are not too fussed about grades is that FWL is primarily mining magnetite. As the name implies, this is a highly magnetic ore (in the old days, they called it "lodestone", and used it as primitive compass).

This means that it is easy, and cheap, to beneficiate the ore using a simple magnetic separator. FWL will use the enriched ore (which will then be over 60% iron) to feed a direct reduction rotary hearth furnace, producing merchant pig iron of 96% grade.