Current chairman Mark Calderwood is passing on the role due to other work commitments, but will remain on the board as a non-executive director.
Campbell has more than 30 years' experience in mineral exploration and over the years has held a number of senior positions, such as the role of managing director of Papillon Resources when it discovered the Fekola gold deposit in Mali.
He has also held senior roles and directorships at a number of companies globally, including 19 years at De Beers.
He is currently a non-executive chairman at Kinloch Resources.
