Karara Mining has promoted its chief financial officer Paul Sims to the newly combined role of chief executive officer and CFO.
Steve Murdoch, who had held the CEO position, has stepped down following a formal board assessment of leadership roles as Karara Mining transitions from project development to operations.
Karara Mining, which is a joint venture between Perth company Gindalbie Metals and AnSteel, one of China's biggest steel makers and iron ore miners, has developed the Karara iron ore project, located 200 kilometres east of Geraldton.
Gindalbie managing director Tim Netscher, who is also managing director of Karara Mining, said Mr Murdoch had played a pivotal role in delivering a world-scale resources project.
"Now that construction and development are complete, commissioning well-advanced and with Karara now moving to steady-state operations, the board of KML believes this is an appropriate time for this transition to occur," he said.
Gindalbie also announced its non-executive director Paul Hallam will replace Robin Marshall as one of two Gindalbie nominated directors on the KML board.
Arafura said the strain of travelling between his Melbourne home and the company's Perth headquarters was behind Mr Tonkin's decision to resign.
Mr Lockyer joined Arafura in June 2006 as its company secretary and chief financial officer.