NFLD. ZINC

The property is on the west side of Newfoundland’s Great Northern Peninsula, about 135 miles north of Deer Lake. In the early 1960s, some companies conducting geochemical work began picking up high values in the area of the mine. Their efforts alerted Leitch Gold Mines and Mastodon- Highland Bell. They, along with an affiliate of Amax, began exploration in 1963. Prospectors Charlie Pegg and Mike Labchuk, working under the direction of J. T. Meagher, discovered zinc mineralization in float and in place. This discovery was followed up by some preliminary drilling and the property was then farmed out to Cominco. This arrangement remained in effect until 1972.

Teck purchased a controlling share position in Leitch and Highland Bell in 1969; and when the Cominco option expired in 1972, Teck and Amax elected to proceed with an intensive drilling program. This program established a mineable reserve of 4.5 million tons at 8.9% zinc.

A feasibility study was completed in 1974 and construction started in July. The mine, rated at 1,500 tons per day, was in production by June of 1975 and operated continuously until April, 1986, when production was suspended because of a sharp reduction in zinc prices.

Sixteen months later, production resumed thanks largely to loans totalling $2.4 million from the provincial government. The reactivation included a commitment to conduct further exploration drilling in an effort to extend the dwindling reserves at the time. Teck announced in May that an important new discovery was made in a previoulsy unexplored area 800 ft northwest of the North L zone. Unfortunately, neither this discovery nor any other exploration results panned out, Patey says. He adds that no further large-scale exploration program is being considered.

On the brighter side, zinc prices dramatically improved in the first quarter of 1988; in fact, they practically doubled, recently peaking at 95 cents per lb(us), “The high price of zinc is especially good in light of the fact that mining has slowed down somewhat. The deposit is pretty well mined out and we’re getting to the end of our reserves (which stand at 431,000 tons grading 8.40% zinc). So with a lower production rate, the strong price of zinc is proving to be a salvation.”

Miners are working mostly in the lower underground workings (about 700 ft below surface), retreating, recovering pillars, and so forth. Production rates have dropped to 40,000 from 45,000 tons per month, reports Patey, and production costs are $34 (Canadian) per ton of ore.

Ore is extracted using room-and- pillar mining, which is the standard method for such flat-lying, Mississippi Valley Type deposits. Trackless underground equipment includes Atlas Copco 3-boom drill jumbos, 5-cu-yd Wagner Scooptrams, 4-cu-yd Caterpillar front-end loaders and 30-ton DJB rear-dump haulage trucks. The ore is truck-hauled from underground to a primary crusher on surface. Mine ventilation is provided by two exhaust raises, supplying about 200,000 cu ft per minute. Auxiliary fans are used to divert fresh air to operating faces. There are four main dewatering pump stations. Eight 300-hp and five 15-hp deep-well turbine pumps (manufactured by Peerless) are used to discharge between 6,000 and 20,000 gallons of mine water per minute. Auxiliary pumping, to the main stations, includes twenty 88-hp and eight 30-hp units.

In additon to the main underground mine, a number of small surface pits have been developed. Underground equipment is used in these pits, except that an airtrack is used for all surface drilling. The pits are relatively small and often the mineralization continues beyond the economic limits of the pit.

The mill can produce a 62% zinc concentrate and achieves a 98% recovery. The concentrate is held in a storage shed on site and is moved to the port as required. Front-end loaders load highway trucks, which transport the concentrate 40 miles to the salt- water port at Hawkes Bay. The shed at the wharf has a storage capacity of 30,000 tons. A conveyor system is used to move this concentrate to 6,000-ton vessels for delivery, mainly to European and U.S. markets.

The success of the Newfoundland Zinc mine can be measured by the fact that, in 1975, production began with eight to 10 years of reserves, and it is now in its 14th year.

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