In the midst of the commodity craze in 2007, Chen waged a hostile takeover of a Hong Kong-listed steelmaker that was ultimately defeated with the backing of steel tycoon Lakshmi Mittal.

FORBES: China's 'Steel Princess' Chased Down For Disappearing Assets

Vice-President Al Gore is keen to strengthen his ties with Richard Gephardt, the House minority leader and a champion of the steel industry, who is backing his presidential bid next year.

ECONOMIST: Steel scrap

Other coal producers started backing out of that market a decade ago, as their customers, the steel companies, suffered from an onslaught of cheap foreign steel.

FORBES: Not King Coal