"Andre brings demonstrated leadership and extensive financial, operational, and strategic experience to this important role," Gatos CEO Dale Andres said.
He said they have been brought on to assist the company as it enters a phase of optimization and growth.
Van Niekerk brings more than 23 years of experience, coming from Nevada Copper where he served as CFO from 2020, the company said.
"He was instrumental in helping to transition Nevada Copper from a development asset to an operating mine and led several successful equity offerings and debt restructurings," Gatos said.
He has also worked as executive vice president and CFO at Golden Star Resources.
"During his 14 years at Golden Star, Andre progressed through various key operational and financial roles with a constant focus on business improvement and value creation," the company said.
Before joining Gatos, Woeller served as director, strategy, and business analysis at Teck Resources.
"James is an experienced mining professional with over 10 years of progressive experience in strategic, commercial, and financial planning roles, including numerous corporate development roles and more than three years as the business development manager on Teck's QB2 project where he advanced numerous optimization initiatives and was the in-country lead on the successful partnering process of a 30% stake to Japanese partners," Gatos said.
Gatos Silver's share price was down 1% day on day at C$3.77 (US$2.92) on June 29. The company had a market capitalization of C$260.74 million at the time.