A BREAKNECK PACE Mobrun

Exploration on Audrey Resources’ Mobrun deposit started with a big splash — a public announcement in late 1985 that Audrey and Corporation Falconbridge Copper (since renamed Minnova Inc.) would spend $10 million — and, in hindsight, a remarkable piece of understatement: the Mobrun holding “is an interesting property , with good exploration potential.” Those were the words of a Falconbridge v.p. (Of necessity, officials of major mining firms usually exude caution about early exploration plays; by comparison, their counterparts at junior exploration firms are prone to shout these things from the rooftops.) As it turned out, the caution was unwarranted. Audrey and Minnova have a legitimate mine that was born as an open-pit polymetallic producer and has since proven to be an excellent underground producer. If there was a hitch at all, it cropped up during mill tests. Recovering the gold and zinc required some fine-tuning.

By the end of October, that problem had been ironed out. At that point, the mine had yielded 1.2 million lb of copper, 2.5 million lb of zinc, 13,000 oz of silver, and nearly 2,000 oz of gold. The whole operation had been running above rated capacity.

The Mobrun has been operating now for about five months. The open pit had been depleted as planned in late October, when ore was being taken exclusively from underground. That ore is apparently easier to crush because it is less hard than the open- pit material. The underground rock is also geologically more stable, says Mine Manager Jean Bailly. Mobrun Notebook Location: ……. Dufresnoy Twp., northwestern Quebec Major owners: ……. Audrey Resources (70%) and Minnova Inc. (30%) Commodities: ……. copper, zinc, gold, and silver Discovery date: ……. 1955 Production decision: ……. June 19, 1987 Start-up: ……. July, 1987 (open pit) and September, 1987 (underground) Capital costs: ……. $14 million Operating costs: ……. $37 per ton (underground) Reserves: ……. 1.3 million tons of 0.81% copper, 3.39% zinc, 1 oz per ton silver and 0.08 oz per ton gold (proven and probable) Means of access: ……. 3-compartment shaft, 6×6 ft to 760 ft in depth Extent of vertical workings: ……. Level 2: haulage drift, at the 656-ft level Mining method: ……. open-stope, long-hole Mining equipment: ……. long-hole drill, JS500, 912 Production rate: ……. 1,045 tons per day (current), 1,100 tons per day (planned) Milling plans: ……. custom-milling at Minnova’s Norbec mill Major contractors: ……. Ross Finlay, Pamo, L. D. Pilon Status: ……. production