Mining giant Anglo American is to invest $1.7bn in a Queensland site in a bid to triple production of metallurgical coal from its Australian assets by 2020.The company hopes its Grosvenor coal project in the Bowen Basin of Queensland, Australia, will yield 5m tonnes of minerals per annum over a 26 year period.The firm said the first coal was expected from the mine in 2013 and the forecast level of investment represented "a highly competitive capital intensity ratio for the project"."Anglo American is delivering substantial near term production growth, across our copper, nickel and iron ore businesses, with two of our four major strategic growth projects already coming on stream during 2011," said chief executive Cynthia Carroll."Grosvenor is the first of our next phase growth projects and will initiate our industry leading production growth of metallurgical coal from our Australian business over the next decade."