I think you're thinking about it too simply. Blending makes...

I think you're thinking about it too simply. Blending makes absolutely perfect sense for the following reasons, and if these conditions are met:

1. It costs about the same whether you're digging up 58% or 65% Fe ore. The value proposition is a little more complex than just looking at revenues; you need to look at costs as well. If you have to shift 10 tonnes of low grade ores to get to one tonne of high grade ore, the lower grade material is actually a bigger cost. That cost will be sunk unless you maximise revenues from it. One way of doing that is blending to make all 11 tonnes saleable
2. I guarantee that, in digging up the 65% ore, MGX will have to dig up a lot more lower grade ore.
3. Blending happens in the mine.

As an example: Using the following ore prices (all taken from a previous post above):
65% Fe price: US$101.60
62% Fe price: US$77.90
58% Fe price: US$49.11

then, selling 13.23t 65% and 10t 58% gives revenues of $1835.89.

Blending the two to get 23.2t of 62% ore will give you about the same revenues ($1810.10).

If the risk of selling 58% ore is much greater than the risk of selling 62% (ie, you may have to stockpile it till you sell it) and/or you need to double handle the ores, then it makes perfect sense to blend down and sell the lot in a timely manner, so avoiding the not inconsiderable stockpile costs.

The exercise becomes even more convincing if you're digging up "waste" at very low Fe grades (say, 52%) for which you'd normally get no revenues (or at least so low as to not even recover mining costs).

Marketing IO is a little more sophisticated and multi dimensional than just selling the highest grade material for the highest price and is the reason most big companies sell a blend, rather than the individual components.

As I said above, volumes and costs are very much part of the sales modelling.

My stop loss order was triggered today, so will wait to see if the SP falls any lower before deciding to buy back in.