Avanti Mining has released the results of a positive NI 43-101 preliminary pre-feasibility study for redevelopment of the Kitsault molybdenum mine 140 km north of Prince Rupert, British Columbia, and has initiated a bankable feasibility study targeted for completion during the fourth quarter of 2010. The feasibility study will include open-pit optimization, additional field investigations and metallurgical testwork, a roaster trade-off study, and bi-product lead and silver recovery metallurgical work. Permitting, marketing and financing activities are also planned for the coming year, with the goal of an early construction start and production by the third quarter of 2013.
The Kitsault property operated from 1967 to 1972 and from 1981 to 1982. Production during those two periods of operation totaled about 30 million lb of molybdenum.
The Kitsault molybdenum pre-feasibility study was prepared by Wardrop and is based on a mine plan that calls for production from a total of 215.3 million mt of proven and probable ore reserves grading 0.085% molybdenum. Production over a 15-year mine life would total 368 million lb of molybdenum. Production of molybdenum in concentrate would average 24.5 million lb/y over the mine life and 29.2 million lb/y during the first five years of production.
Initial capital costs to develop the project are estimated at $641 million. Cash operating costs are estimated at $4.43/lb. Project economics assume a base case estimated average life-of-mine molybdenum price of $15.88/lb.
The open-pit mine has been planned for an operating rate of 40,000-mt/d at a strip ratio of 0.75:1. The ore will be crushed in a gyratory primary crusher, then ground using a SAG-ball mill configuration. The concentrator flowsheet includes rougher and scavenger flotation, four stages of cleaner flotation with three stages of regrinding, thickening, and leaching to remove contaminants. The molybdenum concentrate will be dried and packaged into bags for shipment. Total molybdenum recovery is estimated at 90.6%.
Mining equipment will include two 18-m3 shovels, one 18-m3 loader, and up to 15 177-mt haul trucks. Benches will be drilled on an 8- x 8-m drill pattern. All blast holes will be sampled and assayed for molybdenum. The holes will be loaded and shot with a combination of ANFO and emulsion. Benches are planned to be 10 m in height, and blast hole drilling will be to a depth of 11.6 m, including sub-drill.