A union has called for key executives at Rio Tinto to resign, after the mining giant walked away from a proposed $US19.5 billion ($A24.32 billion) deal with a China state-owned company.

The Australian Workers Union (AWU) said the decision on the much criticised deal amounted to a belated "reality check" by the Rio Tinto board.

"One result of this U-turn should be the resignations of key decision makers at Rio Tinto," AWU national secretary Paul Howes said in a statement on Friday.

"The AWU wants to see successful resource companies in this country, not poorly led corporations who are on bended knees begging for money from inappropriate financial sources."

Rio Tinto on Friday scrapped the proposed tie-up with Aluminum Corporation of China (Chinalco) in favour of a $US15.2 billion ($A18.96 billion) equity raising and an iron ore joint venture with rival BHP Billiton Ltd.

It said the Chinalco deal, which would have lifted the China state-owned enterprise's stake in the company to 18 per cent and given it small stakes in various key mining projects, was no longer viable.

The deal had been strongly criticised by shareholders as being too favourable to Chinalco.

AAP