Shaft-deepening ensures longer life for Agnico-Eagle’s LaRonde division

With stope development advancing considerably and a new headframe recently installed, Agnico-Eagle Mines (TSE) is well-poised to prolong the life of its LaRonde mine well into the next century.

When it visited the operation, 35 miles west of here, The Northern Miner was impressed both by the pace of mining activity and by the sight of the new headframe, which will service the soon-to-be-developed No. 3 shaft.

Since startup in 1988, a string of exploration successes has enabled LaRonde to evolve into a larger and more profitable underground operation. Reserves are now hosted in seven polymetallic lenses, and to reach some of the deeper ore, Agnico has embarked on an ambitious shaft-deepening program.

The No. 1 shaft is expected to reach the planned depth of 3,960 ft. in October, while the No. 2 shaft has already reached its limit of 1,730 ft.

Meanwhile, a $66.6-million program will finance work on the No. 3 shaft. At the time of our visit, contractors had just begun collaring the shaft, which had reached a depth of 35 ft. Agnico has already spent $17.7 million of the total cost on infrastructure, including the installation of a refurbished head frame purchased from a coal mine in England.

When it is completed in 1998, the No. 3 shaft will be North America’s deepest, probing 7,350 ft. below the surface. The company will then have access to the 19, 20N, and 20S zones, as well as downdip extensions of the 6 and 7 zones.

Despite the development activity, production has not slowed down. Indeed, estimated results for 1995 suggest last year’s output will be surpassed.

The mine currently yields 2,000 tonnes of ore per day and, for the first nine months of 1995, produced 130,600 oz. gold and 10.2 million lb. copper. This compares with 115,139 oz. gold and 8.42 million lb. copper for the same period in 1994.

Focus on No. 6 zone

The source of most current production is the upper 6 zone (accessible from the No. 2 shaft), with future production to be derived from zones 6, 7, 19, 20N and 20S.

As of January, proven and probable reserves in zones 1, 4, 5, 6 and 7 stood at 4.9 million tons averaging 0.19 oz. gold per ton. In addition, 20N, 20S, 19 and the extensions of 6 and 7 have a mineral inventory of 22.1 million tons averaging 0.167 oz. gold and 3.8 oz. silver per ton, plus 5.93% zinc and 0.33% copper.

Exploration results continue to suggest that ore may exist at levels even deeper than expected. Holes drilled to test 20N and 20S at depth intersected economic grades of mineralization as deep as 7,000 ft.

A total of six intercepts from the two zones were reported. The best intercept from 20N averaged 0.19 oz. gold and 9 oz. silver per ton, as well as 1.3% copper and 5.54% zinc, over 36 ft. The best intercept from 20S ran 0.37 oz. gold and 2.4 oz. silver, as well as 0.4% copper and 4.9% zinc, over 43.3 ft.

The mine occupies a 1,013-hectare property that underwent only sporadic exploration during the 1960s. It is underlain by an east-west-trending assemblage of Precambrian volcanic and sedimentary rocks. Gold and copper mineralization is hosted within a portion of an east-west-striking, subvertically dipping shear zone known as the Larder Lake-Cadillac Break. At LaRonde, the Break is predominately found within felsic pyroclastics of the Blake River group.