In the March 2020 incident water containing molybdenum ore flowed out of a tailings pond belonging to Yichun Luming Mining Co and into a local river system.
Chinese state and private investors have spent more than $16 billion over the last decade buying copper mines and projects including nearly 50 in Africa.
Shares in Western Copper and Gold declined Tuesday despite a rally in copper prices and the release of a positive PEA for its $3.3 billion Yukon project.