Kennecott chooses Veolia

Kennecott Eagle Minerals, a wholly-owned unit of Rio Tinto, has awarded Veolia Water Solutions & Technologies a contract for the wastewater treatment plant at its Eagle mine, located in Michigan, US.

The mine will be the only primary nickel mine operating in the US, and is expected to produce approximately 136,100t of nickel and 113,400t of copper over the life of the mine.

Veolia’s will implement the patented OPUS high-recovery membrane process, and Liquid Evaporation and Distillation (LED) evaporators and crystallisers for brine management to achieve Zero Liquid Waste Discharge at the mine site.

The wastewater treatment process includes precipitation softening and clarification, filtration, ion exchange softening and a final two-pass reverse osmosis (RO) polishing system. The discharge streams from the process include treated effluent water, metals precipitation sludge, ion exchange regenerant and RO concentrate.

The treated effluent water will be suitable for reuse in the mining process or to release back into the groundwater by a treated water infiltration system. The ion exchange regenerant and RO concentrate liquid wastes will then be sent to the evaporator and crystalliser system and converted to solids which will be disposed of off-site as a non-hazardous solid waste.

The system is designed to treat 100-500 gallons per minute (0.72 million gallons per day) of mine water and will begin operations late in 2011. Veolia will start-up and commission the facility.