Canadian Zinc Corp. announced on October 7 startup of the underground development program at its Prairie Creek zinc-lead-silver mine in Canada’s Northwest Territories. The project is located in the South Mackenzie Mountains, approximately 500 km west of Yellowknife. A mine was largely constructed at the site in 1982 but was placed on care and maintenance due to declining metal prices. The current project benefits from an existing 1,000-mt/d mill and related infrastructure.
Procon Mining and Tunnelling has been awarded the contract for mine rehabilitation, exploration, mine development and initial production at Prairie Creek. The first stage of development will be to re-open and access underground workings by dewatering and re-installing electrical and ventilation services to the 650-m-long decline tunnel, which is located at the end of the mine’s 870-m underground level. The 870-m level portal is located at the mine site adjacent to the mill building. Two other existing underground levels have been developed on the 930-m and 970-m levels.
Canadian Zinc plans to conduct an exploration diamond drill program from underground stations located at the end of the decline tunnel, with the objective of upgrading part of currently inferred resources to the indicated category. An underground drilling rig and other equipment will be mobilized to the site by Procon.
During dewatering of the decline, hydrological monitors will be installed in the 870 tunnel bedrock walls to measure groundwater aquifer flows.
At the same time as the underground program is proceeding, Canadian Zinc will also continue to upgrade and repair existing surface facilities. This work will include completing further site testing and engineering design work for the proposed water storage pond and the waste rock pile. Additional rehabilitation work will be completed on the existing camp to upgrade the trailers to more efficient standards for winter accommodations.
Continued demolition of the old mill powerhouse generators and switchgear will be carried out to prepare the powerhouse for proposed new power generating equipment. Further upgrades of workshops and the sewage treatment plant also will be completed.
A June 2012 Prairie Creek prefeasibility study estimates production at 60,000 mt/y of zinc concentrate containing 76 million lb/y of zinc, and 60,000 mt/y of lead concentrate containing 90 million lb/y of lead and 2.2 million oz/y of silver. Mill throughput is planned at 1,000 mt/d. Mine life is estimated at 11 years. Initial capital expenditures are estimated at C$193 million.
The current Prairie Creek resource represents a small portion of a significantly larger 16-km mineralized system that could, over time, extend the mine’s life.
