Partners update Duck Pond resources

Partners Thundermin Resources (THR-T) and Queenston Mining (QMI-T) have announced the preliminary results of a bankable feasibility study under way at the high-grade Duck Pond copper-zinc massive-sulphide property, 30 km southeast of Buchans, Nfld.

In March, MRDI Canada began a study aimed at determining the economic viability of mining the Duck Pond and Boundary deposits, whose total resources were recently increased to 6.2 million tonnes grading 3.4% copper, 6.2% zinc, 1% lead, 63 grams silver and 0.8 gram gold per tonne, of which 82% are classified as measured and indicated. The latest resources outlined for the Upper Duck lens and Boundary deposit represent an 18% increase over previous estimates.

The feasibility study is focusing on the Upper Duck and Sleeper lenses of the Duck Pond deposit and the open-pit-minable resources at the Boundary deposit. Those resources total 5.4 million tonnes grading 3.5% copper, 6.4% zinc, 1% lead, 65 grams silver and 0.9 gram gold, 94% of which are measured and indicated.

The study sees the project producing 540,000 tonnes per year over a 10-year mine life. Mining would start with an open pit at the Boundary deposit, which has a resource of 480,000 tonnes grading 3.8% copper, 3.3% zinc, 0.4% lead, 26 grams silver and 0.3 gram gold, in three near-surface zones.

At the Upper Duck lens, the underground resource (4.6 million tonnes grading 3.6% copper, 6.6% zinc, 1.1% lead, 69 grams silver and 1 gram gold) would be reached by a 5-by-4.5-metre ramp driven at a 15% grade from surface to a depth of about 500 metres. The smaller Sleeper lens would also be developed from the ramp. Shaft development had been considered, but the lower capital cost of a decline made ramp access a better choice.

The current plan is for drift-and-fill mining on the gently dipping Upper Duck lens. The method would take out panels 6-8 metres wide, and about 5 metres high. About half the tailings would be re-used as paste backfill in mined-out panels. A tailings pond near the proposed portal and mill would take the rest of the tailings.

Lakefield Research has nearly completed a series of metallurgical tests on the massive sulphides from the Upper Duck lens for MRDI. Results to date indicate that the Duck Pond mineralization can be floated to produce two separate concentrates: a copper concentrate with about 23% copper, and a zinc concentrate with about 57% zinc. The precious metals largely report to the copper concentrate, which also carries about 4% zinc. Recoveries of the two principal metals are around 85%.

The study predicts annual production of 67,000 tonnes of copper concentrate and 50,000 tonnes of zinc concentrate. Further tests will determine the economic viability of producing a lead concentrate.

MRDI is now tackling the economic aspects of the operation, which will include projections of operating and capital costs. A minable reserve calculation will follow.

The project has been registered with the Newfoundland Department of Environment and Labour. The draft guidelines for the preparation of an environmental impact statement (EIS) were recently issued for a 40-day public review. Many of the baseline studies for the EIS are already done. The partners hope to begin construction in the second half of 2001. Initial production could start in late 2002.