Rio hit by $1.4bn project blowout TENSIONS between Rio Tinto and Mongolia are threatening to delay production at the $US11.3 billion Oyu Tolgoi copper and gold project, where Rio yesterday revealed a significant cost blowout that has wiped out $US1.5bn ($1.4bn) of value, forced down forecast production and raised expected operating costs. Rio, through its Turquoise Hill subsidiary that is building the mine, yesterday said it remained in discussions with Mongolian officials over a proposed 2013 budget that proposes breaking a 2010 investment agreement by imposing a progressive royalty scheme on Oyu Tolgoi.