Mining group Sirius Minerals has appointed international consultancy and construction group Mace's Executive Chairman, Stephen Pycroft, as a non-executive director.Since 2004 Pycroft served as Chief Executive Officer at Mace and more recently, since 2008, as its Chairman. During his tenure, the firm registered 'phenomenal growth', with turnover increasing from £90m in 2001 to £1.1bn in 2012.He will replace Michael Mainelli, a former non-executive director, who is leaving the company after eight years of service.At Mace, the incoming executive oversaw the delivery of some of the British capital's most iconic projects, including The Shard and the London eye.More recently, Mace secured the contract for preliminary works for Battersea Station. Russell Scrimshaw, Chairman, described Pycroft as a "high-calibre" pick for the board, who will assist in the company's next phase, as it progresses towards securing permission for and construction of the York Potash Project."As of 08:43 the share price remained unchanged at 11p.WS