Australian: MIKE Rann has moved to end uncertainty over development of the nation’s biggest mine, revealing advice from BHP Billiton that the Olympic Dam project would proceed as an open-cut operation. The South Australian Premier’s declaration, in an interview with The Australian, will shore up confidence in the $7billion expansion of the copper, gold and uranium mine when falling commodity prices and the slowing world economy had raised concerns that BHP would back away from converting the …