Gaspe mine back on track after tragic fire of 1987

The 1987 blaze, which claimed the life of one miner, had a profound effect on the community, whose members had to deal with the ensuing layoffs and ponder the possibility of the mine never re-opening.

Now, with existing reserves estimated to provide 7-8 years of mine life and some stability, Noranda can concentrate on modernizing its milling and smelting operations, in particular the latter, which turned exclusively to custom work to keep its furnaces burning after the 1987 tragedy.

“If we improve the smelter, we can make money, because Noranda knows it can compete internationally,” Manager Richard Faucher told The Northern Miner during a tour of the Murdochville facilities.

The mining-milling-smelting operation, situated inland among the mountains of the Gaspe peninsula, about an hour’s drive from the town of Gaspe on the Atlantic Ocean, has about 520 employees.

Faucher said the smelter (70,000- tonnes-per-year capacity) made a small profit in 1988 performing custom work on copper concentrate received fr om Europe and South America, and from zinc producer Brunswick Mining and Smelting (TSE), an associated company in nearby New Brunswick which turns out copper as a byproduct.

About 90% of the material processed by the smelter is copper concentrate, with the remainder arriving in scrap form.

With the E zone of the Murdochville mining camp again in operation, David Alexander, supervisor metallurgical services, said the local mine is providing 30-40% of the smelter material.

The E zone is the third mineralized area to be mined by Noranda at Murdochville and, ironically, it lies under the present townsite. Exploration work has identified a number of deposits or sub-zones within the main E zone. Reserves to date, including the still open E29 deposit, total 5.4 million tonnes grading 1.5% copper. (Some silver is also being recovered.)

Chief geologist at the Gaspe operation, Pierre Bernard, said drilling has indicated a potential sizeable reserve from other E zone deposits. The exploration budget for 1989 has been increased to about $1.1 million, with the company providing about $600,000 and the Quebec government the remainder.

“We have to build our reserves and make sure we have long-term reserves,” Faucher said.

Production from the E32 deposit is 3,000 tonnes per day, five days per week. Described by Gaston Morin, chief mining engineer, as being 1,100 ft long, 300 ft wide and 200 ft high, dipping at about 30 degrees and sitting at a depth of more than 2,000 ft, the deposit is being mined from the bottom up. “We’re mining it like a cone,” Morin said.

The preferred mining method is longhole and ore haulage is trackless. Broken rock is transported to an ore pass, which channels the material downwards to the computerized No 5 crusher situated in the deepest part of the mine, at a vertical depth of 2,400 ft. The crushed rock is then transported back to the surface for milling via a conveyor belt system.

Access to the E zone is by way of the portal that served the original Needle Mountain deposit, development of which was started in the early 1950s. The mill first began treating Needle Mountain ore in 1955; the smelter went into operation later that same year. Needle Mountain reserves at the end of 1955 amounted to 67 million tonnes averaging 1.3%. A weak copper price in 1982 brought mining there to a temporary halt. In 1984 underground operations started again.

The second mine was the open- pit Copper Mountain operation, which at the time of its opening in 1968, hosted reserves of 31 million tonnes grading 0.71%.

A decision was made to expand the open-pit operation and in 1973 a second mill, with a capacity of 22,500 tonnes per day, was put into service. (The first mill’s capacity, by 1968, had been expanded to 11,500 tonnes per day.)

To allow access to the envisaged open pit, the top of Copper Mountain, containing 33.6 million tonnes averaging 0.45% of oxidized copper material, was removed and stockpiled elsewhere on the property. The oxidized copper (more than half of which remains untouched) was used to feed a new vat facility which could treat 5,000 tonnes material per day. Both the open pit and oxidized copper treatment facility ceased operations in 1982.

Not neglected in all of the expansion was the smelter, which had its capacity increased. A sulphuric acid plant was added in 1972.

Cause of the 1987 fire, which destroyed 6,000 ft of a rubber conveyor system, was never clearly determined, Faucher said. The new belt is fire-resistant and with its installation came new safety equipment, such as a sprinkler system and smoke and heat detectors.

Noranda budgeted $15 million and $5 million in working capital to get the mine operating again. Faucher said actual costs totalled $15 million and the work was completed two months ahead of schedule.

The E32 deposit was in its start- up period when the fire broke out. Noranda had spent $53 million to bring the deposit into production.

Activity at the mill (the project’s original mill) is not what it once was — daily input now is a steady 3,000 tonnes. But there are challenges, chief metallurgist Serge St. Pierre pointed out, such as trying to increase the copper content in the milled concentrate from 19-20% to a more desirable 24%.

As part of its workload, the mill is producing backfill (to be mixed with surface rockfill) for the E zone mining operation.

Plans to update the smelter, a 7-day-per-week operation, have been in the works for a few years. One of the improvements under way is the installation of an oxygen plant which would reduce fuel consumption and increase capacity.

The copper anodes turned out by the smelter — each anode weighs about 650 lb and is 99.5% pure — are trucked to Noranda’s CCR refinery in Montreal for final processing.

The sulphuric acid recovered in the smelting operation is trucked to the nearby town of Gaspe for storage in two tanks. The acid is then loaded on to a ship for delivery to Noranda’s U.S. customers.

The town of Gaspe possesses a natural harbor which lends itself to the importation of copper concentrate and exportation of sulphuric acid by ship, Faucher pointed out. “We intend to build on that,” he said.

]]>