The Chinese would be looking at an capital/turnover ratio of...

The Chinese would be looking at an capital/turnover ratio of about 2. That's like a price/sales ratio for a company. BHP's p/s for example is currently 3, so 2 is in a reasonable ball-park.

Iron ore is already back into bull market territory, and if the Chinese are serious about Belt and Roads then $3.7B is barely small change. For China Railway in particular to guarantee supply for the B&R infrastructure - rather than leaving itself at the mercy of the market - makes a huge amount of sense. Just look at how BHP and co have gouged the market in past years, and it's not just sensible, it's essential.

Will B&R actually happen? I don't know. But Xi Jinping is on a massive power trip, and like various power-hungry leaders of the past he won't care about whether conditions are good for everyone at home before he embarks on foreign adventures. IRD certainly looks like an interesting adventure!