My comments below on all this talk about impurites & how to get...

My comments below on all this talk about impurites & how to get rid off them.

The key words during beneficiation are Flux & Slag.

During the beneficiation process in the blast furnace where the temperature is 2000 deg C, they use limestone as a flux. At high temperatures, limestone (which is predominantly CaCO3) breaks into CaO & CO2.

The CaO combines with SiO2 to produce CaSiO3 aka Slag. This slag along with the molten iron settles a tthe bottom of the furnace & being less dense then the molten iron floats above it.

Both the slag & molten iron are then run off separately. The molten iron at this stage is solidified & is called Pig Iron while the slag has varied uses in highways construction or agriculture.

Limestone (or dolomite) is preferred flux as its not expensive at all, hence its use in the furnace.

All thats important is for the companies to set a cut off level for raw Fe ore before dumping it into the furnace & hence the reason why Assaying is critical & 56% is acceptable.

cheers