Gerry Kaczmarek has been appointed chief financial officer and company secretary of Troy Resources. Mr Kaczmarek held the same positions at Troy from 1998 to 2008.
Dr Roric Smith has joined the board of Saracen Mineral Holdings as independent non-executive director.
Mark Pitts has been appointed joint company secretary of Spectrum Rare Earths.
Tyrone Jones has been appointed chief executive of Sprintex. He was its chief operating officer, having joined the company in 2014. David White, who assumed the role of acting chief executive, will remain with the company as deputy chair.