So I'm pretty sure Japan wouldnt be exporting any iron to Mexico plant.

From Izabella's article

"In other words, if there is any slowdown in China, it is certainly not negatively affecting the major bulk trade flows into the country and therefore the related shipping market. In fact, it is quite the opposite. If we also compare the y-o-y result of iron ore imports into South Korea and Japan, the picture becomes even more confusing for some — Japanese iron ore imports in H1 2012 as up 4.4% and South Korea imports are up 4.7% compared to H1 2011.. No surprise global steel production is up nearly 1% y-o-y then!

[emphasis added]