Warburton was a founding director of the company and has been on the board since its formation six years ago.
Chairman Michael Wolley will remain on the board as an independent non-executive director.
CEO Andrew Richards has stepped down to pursue other interests, but will consult to the company.
Another founding independent non-executive director, Bo Zhou, has resigned due to increased work commitments.
Discovery Metals has appointed chartered accountant and former Riversdale Mining chief financial officer Niall Lenahan as an independent non-executive director.
Former Goodrich Resources managing director David Busch has been announced as the new MD of Argent Resources.
Hongwei Lui has been appointed as a non-executive director of CuDeco.
Liu is a director of shareholder and potential offtake partner Oceanwide International Resources Investment Co.
CRU Group consultant and MiningNewsPremium.net contributor Dr Allan Trench has been appointed as a director of Enterprise Metals after founding chairman Paul Larsen resigned as a non-executive director.
Nigel Ferguson has resigned as a director of Burey Gold after seven years on the board.
Nathan McMahon has resigned as a non-executive director of White Star Resources.
BrazIron executive director Neil O’Loughlin has reverted to a non-executive role as the company’s search for a CEO continues.
Finally, Angeline Hicks has replaced Mundo Minerals Ashley Pattison as company secretary, allowing Pattison to focus on his role as MD and CEO of the company.