The Wolverine Mine, owned by Yukon Zinc Corporation, is located in southeastern Yukon, Canada. It is an underground mining operation, producing zinc, silver, copper, gold and lead. The Wolverine Mine water supply contains naturally elevated levels of metals, e.g., selenium, zinc, copper and cadmium, while water recycling between the mill/floatation circuits and the tailings pond is constantly increasing contaminant concentrations.
Development of a water treatment system for various mill process waters began in 2006 during project permitting. Both chemical and biological approaches were examined as potential selenium removal methods. Chemical methods proved ineffective at treating selenium and therefore, a newly developed Electro-Biochemical Reactor (EBR) treatment system was evaluated.
This paper discusses laboratory and pilot test results that demonstrated up to 99.9% selenium removal from various process waters ranging from 0.5 - 9 mg/L total selenium in bench testing to over 3.5 mg/L total selenium in pilot test waters. In addition to successful selenium treatment, the EBR pilot system efficiently removed mill process chemicals, inorganics, such as cyanides and nitrates, and metals including antimony, cadmium, copper, lead, silver, zinc, etc., to at or below license discharge criteria. Based on the testing conducted, development of full-scale EBR facility is underway.
