The opponents include the prominent Swiss-based (but Russia-linked) Trans World Group, which says that a ban on tolling is impractical, because Russian firms cannot be sure of always having the hard currency to pay for the continuous supply of imported ore they need.

ECONOMIST: A heavy toll

After months of negotiations, China's steelmakers agreed to pay up to double the price for the iron ore they buy from Rio Tinto, the biggest-ever annual rise in the cost of the commodity.

ECONOMIST: Business this week

Rio instead raised cash to pay down hefty debts with a rights issue and also announced an iron ore tie-up with BHP (which itself had tried, and failed, to acquire Rio in 2008).

ECONOMIST: China and Rio Tinto: A souring relationship | The

If all goes well, the revenues produced from exporting iron ore to China in the next 2-3 years will then pay for a steelworks and, ultimately, cement and even car factories.

BBC: Brazil: No reverso

Basically, to assess mineral content the geologists drill some holes and assay the ore for potash exploring percentage of mineral content as well as the thickness of the pay zone.

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