The German group has raised its shareholding in Argor-Heraeus to 100 percent from about 33 percent previously.
No financial details are being released about the deal, which still requires approval from relevant authorities.
The sellers were Germany’s Commerzbank , Austrian state mint Muenze Oesterreich and Argor-Heraeus management, Heraeus said.
Argor-Heraeus has around 300 employees with operations in Switzerland, Germany, Italy and South America.
It is involved in refining gold ore, recycling of precious metals and industrial processing of bars, coins, alloys and semi-finished products.
“With the full takeover of the shareholdings, Heraeus is now in the position to fully profit from Argors competence and capacity for gold and silver,” Heraeus CEO Jan Rinnert said in a statement.
(Reporting by Michael Hogan; editing by Jason Neely)