Rio Tinto's rewind to 2004 shows it's a victim of own success

London

RIO Tinto Group has to work twice as hard to turn the profit it did a decade ago.

Back in 2004, the world's second biggest mining company produced about 60 million tonnes of iron ore and reported underlying earnings of US$1.3 billion in the second half of the year. Now it extracts about 130 million tonnes in six months for roughly the same profit.

The numbers show how Rio, like the rest of the mining industry, has been a victim of its own success.

The company poured US$90 billion into expanding production in the last decade, mostly in iron ore, its primary earnings driver, as China's unprecedented economic boom led to soaring commodity prices and delivered re…