FADING ROYALTY?

The mine’s closure following the April, 1987, fire, which destroyed a rubber conveyor system, was a major blow to this community of about 2,000 residents. The town, built by Noranda in the early 1950s among the inland mountains of the Gaspe Peninsula, sits about 1,825 ft (550 m) above sea level and once supported a population more than twice the current number. The town flourished for years as Noranda mined Needle Mountain from underground and Copper Mountain by open pit.

Last year, company attention focused on the division’s smelter (current capacity, 70,000 tonnes per year), which first went into operation in late 1955. A decision was made to turn exclusively to custom smelting and, according to Manager Richard Faucher, it proved to be a sound move. (See accompanying story on the smelter.)

The smelting operation made a small profit in 1988, he said, and management is again seriously considering modernization plans. “If we improve the smelter, we can make money, because Noranda knows it can compete internationally,” Faucher said.

Gaspe Mines employs about 520 people, 220 workers at the mine and concentrator and the remainder connected with the smelter. At the start of this decade, the Murdochville operation counted almost four times as many workers.

The E zone, which sits under the townsite and comprises a number of sub-zones or deposits, is the third mineralized area to be worked by Gaspe Mines, which was incorporated in 1947 under the name Gaspe Copper Mines. Credited with the original copper discovery, in 1921, were the Miller brothers. Noranda Exploration acquired a property option in 1938. A portal serves as an entry point into the E Zone and the underground N eedle Mountain mine which, in 1951, became the first mineralized area to be worked from underground. The well-worn ramp, 18 ft (5.5 m) wide and 20 ft (6 m) high, leads to a maze of drifts and crosscuts. Huge pillars still stand tall from the “room- and-pillar” mining days of the deposit.

Chief Mining Engineer Gaston Morin said the E32 deposit is 1,100 ft long, 300 ft wide, 200 ft high and dipping at about 30 degrees . The deposit sits at a vertical depth of 2,000 ft and is being mined from the bottom up “like a cone,” Morin said.

Longhole mining is the sole method used. Ore haulage is trackless, with the broken rock channelled through an ore pass to the No. 5 crusher, which sits at the deepest part of the mine at a vertical depth of 2,400 ft. The crushed rock is transported back to surface by way of a new 3-part conveyor system complete with a fire retardant belt and other safety features (see accompanying story on new conveyor system).

Installation of the new conveyor system allowed the company to computerize the operation of No. 5 crusher. A control room equipped with video monitors linked to strategically placed cameras allows workers to operate both the crusher and conveyor belt and watch the belt system at various locations.

The production rate at the E32 deposit is 3,000 tonnes per day, five days per week. Two shifts per day have been organized, 7 a.m. to 5 p.m. and 5 p.m. to 3 a.m., making for a production target of 1,500 tonnes per day for each shift.

The morning The Northern Miner Magazine visited the No. 5 crusher operation, the crusher itself was silent, the ore pass empty and the conveyor belt motionless. The workers, it turned out, had processed about 1,400 tonnes of rock during the first three hours of the shift, and temporarily had turned their attention elsewhere. Ventilation of the E zone is by way of two 10×16-ft rectangular raises, one 500 ft long and the other 1,100 ft. Each raise provides 220,000 cu ft of air per min. At the 1800 level, two secondary ventilation fans, each 66 inches in diameter and handling 100,000 cu ft per min, push air through the exploration drifts into the E32 deposit.

Mine development equipment includes three Jarvis-Clark giraffes (each equipped with two booms, one for a man basket and one for a drifter) for scaling and bolting, and five pneumatic Jarvis-Clark (three, 3-boom and two, 2-boom) jumbos. Used to transport material are one ST-5 Wagner, two ST-3 Wagner, three ST-2 Wagner load-haul-dumps and six JDT-413 Jarvis Clark haulage trucks.

Production equipment includes a Tamrock Solo 608 RA (2 1/2-inch drill holes) for cable bolting, two down- the-hole CMM-2 Ingersoll-Rand (6 1/2- inch-diameter) drills, two JS-800 Jarvis Clark vehicles and one ST-8B Wagner for mucking, and a boxhole Block Holer for secondary drilling.

Chief Geologist Pierre Bernard said drilling has indicated the possibility of substantial additional reserves within the other E zone deposits. Gaspe Mines has budgeted about $1.1 million for exploration work this year; the company will provide about $600,000 of that total and the Quebec government the remainder.

The underground tour included a brief visit to where a cavernous stope, about 150 ft deep, was being prepared. Part of the development includes installation of a track for rail cars along a 1,900-ft drift to transport backfill and rockfill to the stope. The mill provides the backfill, while the rockfill comes from material which is crushed and stockpiled on surface.

At the mill, activity, with daily throughput of 3,000 tonnes, is more subdued than in previous times. The first of two concentrators built by Gaspe Mines, the facility has the capacity to handle 11,500 tonnes per day. Still, there are challenges, such as trying to boost the copper content of the final concentrate from the current 19%-20% to a more desirable 24%, Chief Metallurgist Serge St. Pierre said. Improving the grade of the concentrate, Faucher said, would mean a decreased waste fraction to the smelter, thereby increasing the capacity available for the custom smelting of outside material.

Flotation circuits concentrate the ore. St. Pierre said the mill has three banks for roughing and three banks for cleaning. At the time of our April visit, the company plan was to switch to flotation columns in June; the mill already has one column (not then in use) and plans call for the purchase of a second one. While the columns would replace the smaller cells, St. Pierre said that should a second cleaning step be required, the cells would be brought back into service.

Mill equipment includes one rod mill and two ball mills, each 11×13 ft in size. The mill also has three fine orebins, two for grinding ore from the E zone and one to grind the stockpiled surface material used for backfill. Three tailings dams contain mill tailings. Two of the ponds are being revegetated and the third has ample capacity, Faucher said. Past mining activity at the Murdochville camp includes the Needle Mountain deposit where, at the beginning of 1956, reserves totalled 67 million tonnes grading 1.3% copper, and the open-pit Copper Mountain operation, which when it was started up in 1968 hosted reserves of 31 million tonnes grading 0.71%.

Expansion of the open-pit operation was accompanied by construction in 1973 of a second mill with a capacity of 22,500 tonnes per day. To mine the open pit, the top of Copper Mountain, containing 33.6 million tonnes grading 0.45% oxidized copper material, was removed and stockpiled. (Almost 21 million tonnes of the oxidized material remains to be treated.) A new vat facility whi
ch could handle 5,000 tonnes per day was built to treat the oxidized copper.

In 1982, high operating costs and low copper prices led to the closing of both the open-pit and oxidized copper treatment facility. Also that year, underground mining operations were suspended. The underground operations were resumed in August, 1984.

Bernard said a substantial amount of low-grade material (more than 70 million tonnes averaging 0.43%), considered an uneconomic deposit at current copper prices, lies beneath the Copper Mountain pit.

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