* Mine seeks to turn corner after bruising 2012 * Resources show significant potential for expansion -CEO * Collahuasi is world's No. 3 copper mine * World No.1 copper producer Chile seen boosting output By Fabian Cambero SANTIAGO, Feb 6 (Reuters) - World No. 3 copper mine Collahuasi said on Wednesday its mineral resources grew by 19 percent to 9 billion tonnes last year compared with 2011 levels, due in part to new drilling campaigns and improvements in mining design.