Mr Burns was Managing Director of Sphere Minerals Limited from 1998 – 2010. During this period, the company acquired and evaluated iron ore properties in Mauritania, West Africa. Sphere was subsequently taken over by Xstrata PLC in November 2010 for $514 million. Mr Burns was also a non-executive Chairman of Shield Mining Limited (Shield), which was spun out of Sphere in 2006. Shield was a gold and base metals exploration company active in Mauritania and was taken over by Gryphon Minerals Limited in mid-2010.