Citi’s 'end of the Iron Age' note triggers waves of downgrades

[caption id="attachment_822418" align="aligncenter" width="600"] Port Hedland in the iron ore-rich Pilbara region of Western Australia.[/caption] Iron ore miners including giants BHP Billiton (ASX:BHP) and Rio Tinto (ASX:RIO) saw their stocks trade slightly lower on Tuesday as Standard and Poor's (S&P) placed several producers on...