Bear Creek Mining has announced the results of an updated feasibility study of its 100% owned Corani silver-lead-zinc project in Puno department, southern Peru. The study includes significant modifications to the processing and construction designs envisioned in a 2011 feasibility study, including dry-stacking of the tailings, resulting in elimination of the tailings impoundment and fresh water storage dams; revision of the mine sequencing plan and new metallurgical recovery modeling, with higher confidence in recovery predictions; and reconfiguration of infrastructure layouts and equipment selection for certain areas of the processing facility.
The updated Corani feasibility study is based on 137.7 million mt of proven and probable reserves grading 51.7 g/mt silver, 0.91% lead, and 0.59% zinc. Open-pit mining would feed a 22,500-mt/d processing plant to produce separate lead-silver and zinc-silver concentrates. Contained silver production would average 13.4 million oz/y during the first five years of production and 8.4 million oz/y over a mine life of 18 years.
Initial capital to develop the Corani project is estimated at $625 million, with payback in 3.6 years. All-in sustaining silver production costs, net of byproduct credits for lead and zinc, are estimated at negative $0.23/oz during the first five years of operation and $3.85/oz life of mine.
Bear Creek anticipates that the design and operating improvements incorporated in the updated feasibility study will require only a modification of the Corani project’s existing, approved Environmental and Social Impact Assessment (ESIA), without the necessity for additional public hearings. Further, as the environmental impact of the proposed operation has been reduced, the company anticipates that final permitting timelines will shorten, and costs will be lower than previously anticipated.
Bear Creek is currently focusing on preparations for Corani development, starting with the preparation and submission of an amended ESIA in the third quarter of 2015. Concurrently, the company is starting the mine permitting process, of which the amended ESIA will form a key component. The company is also starting evaluation of potential mine financing options and expects to enter into discussions with potential financing partners.
The goal of these activities is to ensure that necessary information, permits, approvals, and relationships are in place to allow consideration of a production decision as early as 2016.
Bear Creek President and CEO Andrew Swarthout said, “Corani remains one of the world’s largest undeveloped silver-base metal deposits and is the key driver for growth at Bear Creek. As a result of the modifications to the Corani mine design in the updated 2015 Corani feasibility study, we have created a more compact, efficient, and cost-effective operation, with a smaller physical and environmental footprint, which we expect will result in a shorter and less costly path to permitting.
“We were able to further refine the geo-metallurgical model and mine sequencing, which led to an 8% increase in overall silver recovery with a 7% increase in silver reporting to the lead concentrate relative to zinc, partially offsetting the effects of a small reduction in ore reserves.”
The updated Corani feasibility study was led by M3 Engineering & Technology, with support from Global Resource Engineering and others.