The Detour Lake gold mine, northeast of Timmins, Ont., shifted from an open-pit to an underground operation late last year. At the time of writing, the operators were processing low grade, stockpiled ore from the open pit while the underground mine was entering production. The start-up of the underground phase has been eagerly-awaited. Shortly after the mine began open-pit operation back in November, 1983, at a cost of $139 million, it was troubled by three problems: lower-than-anticipated grade, tonnage and reserves. Adding to the woes was the then- tumbling price of gold.
In light of these problems, plans were revised in an attempt to transform the project from a money-loser to a winner. Costs were cut and efficiencies were improved; in 1985, the company embarked on a 2-phase underground development program at a combined cost of about $61 million.
The investment seems to be paying off. Full production of 1,980 tonnes from underground expected to be reached in March.
Most of the Detour Lake ore lies at, or adjacent to, the contact between an ultramafic unit and a series of mafic volcanics. The Main zone, which follows the contact, is spatially associated with a chert horizon accompanied by quartz veins and sulphide enrichment. The Main zone strikes east-west, dips steeply north and plunges about 45 degrees to the west. Structurally, the ore is located on the nose of an open fold. The remainder of the ore is in narrow quartz veins which splay-off the chert horizon at a strike of about 45 degrees and a near-vertical dip. Here the gold values are more erratic and have a lower-than-average grade. Detour Lake Notebook Location: ……. 130 miles northeast of Timmins, Ont. Major Owners: ……. Placer Dome (50%), Amoco Canada Petroleum Co. (50%) Commodity: ……. gold Discovery date: ……. 1974 Production decision: ……. October, 1986 (underground mine) Start-up: ……. Dec 1, 1987 (underground) Capital costs: ……. $50 million Reserves: ……. 8.2 million tons grading 0.152 oz per ton (probable) Means of Access: ……. 5-compartment shaft, about 2,000 ft deep Extent of vertical workings: ……. unavailable Mining method: ……. mechanized cut-and-fill Mining equipment: ……. trackless Production rate: ……. 1,980 tons per day from underground Milling plans: ……. on-site Major contractors: ……. McIsaac Mining and Tunnelling, American Mine Services, J.S. Redpath Ltd. Status: ……. production
Be the first to comment on "A BREAKNECK PACE Detour Lake"