BQE Water Inc, a leader in the treatment and management of mine-impacted waters, reports the successful completion of on-site pilot demonstration of its patented Selen-IX™ process at the Coeur Wharf heap leach gold mine in the northern Black Hills of South Dakota, US. The demonstration was the first critical step in the process of implementing selenium treatment that meets permit conditions associated with the mine expansion. The project is now fast tracked for full scale implementation in 2024.
Selen-IX it says was selected as the Best Available Technology (BAT) for this project over biological selenium reduction systems due to several factors including: ability to avoid reliance on dilution by meeting the in-stream limit directly at the end of pipe, performance unaffected by cold water temperatures, ability to operate in intermittent mode, ability to handle large and rapid fluctuations in feed flow, and minimisation of residue management costs.
Although there are multiple successful large scale Selen-IX plants currently in operation, Coeur requested the pilot demonstration to verify the process performance on the Wharf mine influenced water prior to initiating engineering design to minimise implementation risks. The pilot phase of the project involved a rapid deployment, start-up, and continuous operation of BQE’s mobile Selen-IX™ unit at site.
The campaign was accompanied by a rigorous sampling program to monitor process performance under variable feed conditions and included characterisation of the selenium solids to inform residue management and disposal in the full scale. BQE Water states: “Unlike biological systems that do not allow rapid demonstration due to the lengthy process inoculation and acclimation prior to reaching a steady state operation, the Selen-IX process starts to produce on-spec effluent at the design flow immediately and reaches a steady state within days.”
David Kratochvil, President & CEO of BQE Water, commented: “I am very proud of our technical team for delivering yet another flawless pilot project execution in close collaboration with the client’s operations personnel to meet and exceed all project objectives. This project also demonstrates the unique value of the Selen-IX process for clients with short timelines to reach environmental compliance by treating water at design capacity and producing target effluent water quality immediately after start-up. This feature is critical for Wharf as it fast tracks the full-scale treatment implementation in accordance with the mine permit, and BQE is committed to delivering technical excellence through all stages of the project and have a fifth Selen-IX plant in operation as soon as possible.”
