you're looking at it far too simplistically. China imports most...

you're looking at it far too simplistically. China imports most of the world's iron ore because it produces most of the world's steel. A large amount of that steel stays in China but im sure a lot gets exported too. The reasons why China produces most of the world's steel is because wages are low and their population and infrastructure spend is massive amongst other things.

China may not always be the world's steel producer as it's economy changes but right now it certainly is and likely to remain so well into the next decade.

Finally unless you've discovered a replacement for steel then steel/iron ore will be required so long as the world continues to build bridges, buildings etc, in fact some forecasts for steel have the metal in supply deficit in the years to come.