Eighty-three years ago, Joseph Obalski steered his canoe into a hitherto little-explored mineralized region in the northwestern part of the province. As Quebec’s inspector of mines, he had examined the copper, iron and asbestos samples brought out by Peter McKenzie, a fur trader from England who had explored the area the previous year, and was very impressed. If only the area were as rich with minerals as those samples suggested … It was. In his official 1904 report to the minister of mines, Obalski didn’t hold back his optimism: “I cannot too earnestly call your attention to this new district and to the important discoveries made there, for I consider it as destined to play a great role in the industrial development of our Province.”
Today Chibougamau is one of Canada’s major mining camps. The area covers roughly 1,000 square miles and is centred around Lake Chibougamau, about 300 miles north of Montreal. The name means “meeting place” in Native language; i.e., where the Cree and Montagnais tribes meet.
Last year alone more than two million tonnes of ore were extracted from the camp, according to figures obtained from the Quebec government. From that was produced 255,461 oz of gold, 280,150 oz of silver and 19,318 tons of copper. Combined, the three metals mined in Chibougamau last year carried a value of $156.5 million (76% of that coming from gold production) compared to $141.8 million in 1985. The area has come a long way from Peter McKenzie’s bag of assorted rock samples.
Several mineralized showings in the Chibougamau district were known from the start of the twentieth century. However, mining development has been slow and sporadic. After a halt following the ambiguous conclusions of the Chibougamau Geological Commission of 1911, a later wave of exploration brought to light the principal mineralized sites. Mines were constructed, only to be shut down as a result of the Great Depression and the Second World War.
It was not until 1950 that the real boom was on, partly caused by the construction of a 48-mile, all-weather gravel road linking the town of St. Felicien in the Lake St. John area to the Chibougamau townsite. Among the many companies which staked properties and engaged in exploration work that year were: Campbell Chibougamau Mines (now Camchib Resources); Opemiska Copper Mines (now Minnova Inc.); Kayrand Mining and Development Co. (now Chib- Kayrand Copper Mines); Merrill Island Mining Corp. (now absorbed into Francana Oil and Gas); and a group of smaller companies that were later merged into Patino Mining Corp. The first copper producer was Opemiska which opened in 1953, and Chibougamau became the most important copper-producing region in eastern Canada between 1960 and 1972. In 1979 the value of the region’s gold production exceeded that of copper and the yellow metal is now Chiboubamau’s principal natural resource. Roughly 38% of all the gold mined in Quebec comes from the Chibougamau area (including neighboring Chapais) — not bad for what has traditionally been regarded as a copper camp.
When I visited the camp last May, five companies had nine mines on the go, producing gold, silver and copper. They are: Northgate Exploration (the Copper Rand and Portage mines); Meston Lake Resources (the Joe Mann mine); Campbell Resources (which manages the Joe Mann in addition to the S-3 and Cedar Bay mines); Minnova Inc. (the Springer, Cooke and Lac Shortt mines); and Bachelor Lake Gold Mines. What follows is a round- up of activity in the area. Meston Lake and Campbell Resources
The big news this year in Chibougamau has been the start-up of Meston Lake’s Joe Mann gold mine. It had been operated twice before, beginning in the mid-1950s, with 869,000 tons having already been mined out of the upper levels. In 1983, after the mine was flooded a third time, then- president George Bodnar Jr. entered a deal whereby Toronto-based Campbell Resources agreed to provide Meston with $10 million in flow- through funds over a 4-year period (Campbell owns 65% of Meston and operates the mine under contract). The money was spent exploring the deposit and has resulted in slightly less than one million tons grading 0.22 oz gold per ton. Moreover it has lent credibility to the adage that the best place to look for a new mine is an old mine.
The Joe Mann started up in April and is now turning out 700 tons per day, which is expected to continue for at least the next 5-6 years. Campbell President Richard Lister is hoping for an even longer mine life, arguing that the real basis for excitement is the strong indication of future potential ore both to the east and west of the shaft. “Besides the diluted and mineable reserves of 910,000 tons, surface drilling has indicated that there may be at least another two million tons of ore,” he stresses. “The lower we go, the wider the ore; and the grade here is probably even better than the grade in the upper levels.”
In addition to 0.22 oz gold, reserves at Joe Mann have an average grade of 0.18 oz silver and 0.30% copper. Although the focus is definitely on gold, copper and silver prices have improved enough to make them an added sweetener.
Long-hole mining at Joe Mann was being carried out east of the shaft last May, between the 900 and 1,600 levels. The shaft extends to 1,650 ft and drifts have been extended 900 ft to the east, towards Norhart Lake. Campbell was drilling below and to the east of the existing shaft and was planning to drill to the west.
Meston’s chief geologist Raymond Fournier says some major geological discoveries have been made on the property. “The success of the operation is that we have proceeded to understand a complex reverse fault system. We now know that a young fault, which dips to the east, displaces the old fault, which dips to the west. They meet at the 600-ft level, causing a real turmoil. We are progressively expanding this mass of ore.”
Joe Mann isn’t the only new mine on the Chibougamau block. January saw the start-up of Campbell’s S-3 mine. Resrves here are 474,024 tons grading 0.159 oz gold and 0.46% copper. The company reports that initial grade was slightly lower than projected, but production has exceeded the scheduled 500-ton-per-day rate. It is, then, with some justification when Lister proclaims: “I don’t know of any other company in Canada that has been able to start up two gold mines, as successfully, in such a short period.” He expects Campbell will produce 60,000 oz of gold in 1988.
The 800-ft level has already been developed and there are plans to continue exploration drifting and drilling along strike on the 1,025-ft level. Using mostly long-hole mining with some shrinkage stoping, 500 tons per day will be produced from between the 675- and 1,025-ft levels. The outlined orebody lies below Lake Chibougamau and is accessible by way of the Henderson 1 shaft on Portage Island, an artificial mound of rock about 5,000 ft from the nearest shoreline.
Widely considered the backbone of Campbell’s entire operation, the Henderson 2 mine has hefty reserves of 5.7 million tons grading 0.080 oz gold and a comparatively high copper content of 1.5%. Like the S-3, it lies under Lake Chiboubamau, off the shore of Portage Island. The mine was developed by two shafts, as well as an internal shaft which has allowed for the mining of a relatively new gold structure lying at depth. Discovered back in 1957, the operation was brought into production 10 years later. The method here is cut-and-fill, with work concentrated between the 2,270- and 2,720-ft levels. The driving of a decline under the 2,700-ft level (where the zone is believed highest in copper) began in May and significant ore values were expected to have been reached by presstime. More than half of the $3-million underground development costs are being paid by the Quebec government — which, needless to say, is good news for Campbell’s shareholders.
Also owned by Campbell is the 29-year-old Cedar Bay gold-copper mine, another cut-and-fill operation. Reserves here are 971,038 tons, with a production rate of 350 tons per day grading 0.14 oz gold and 1.10
% copper. Most of the current production is from the 500- to 950-ft levels, but the bottom-most (2,200-ft) level is being developed and it is expected that 30% of production will soon come from beneath this level. In this new zone are about one million tons, grading 0.16 oz gold and more than 1% copper, says William Zuckerkandel, an assistant director of Camchib Mines, a wholly-owned subsidiary. The current plan is to sink the Cedar Bay shaft to 3,855 ft, in which case long- hole mining would be employed.
The operating cost for all four mines is $310(US) per oz, which includes $45 per oz for development, Lister says.
The Camchib Mines mill, which began operating back in 1955, now processes an average of 21,500 tons of ore per day from all four mines combined. A 90% gold recovery is achieved, using a gravity concentration circuit, i.e. pinched sluice boxes with Knelson concentrators.* One reason for going with the gravity circuit (as opposed to, say, carbon-in pulp) is the ore’s copper content, says mill superintendent Andre Cauchon. Another reason is the relatively high percentage of free gold which occurs, especially at the Joe Mann and S-3 mines; in other words, much of the gold is not locked in with sulphides. Material collected in the pinched sluice is screened and the oversized material goes back in the circuit — a process which involves no labor whatsoever. 00 3/8 *The pinched sluice differs from the riffled sluice both in the smooth bottom of the trough and in the method of concentrate removal. In the riffled sluices heavies settle into the gaps between the riffles set at right angles to the flow and are removed intermittently, whereas in a pinched sluice the flow regime is such that heavies are removed continuously. Northgate Exploration
While the pinched sluice is well- suited to Campbell’s relatively fine material (the average is 30%-35% minus 150 mesh), the standard sluice method combined with a jig is preferred for the coarser material at Northgate’s mill. A new flash flotation process has recently been added at the mill, allowing the company to cut processing costs by $25,000 per month. The mill processes ore from the company’s Portage and Copper Rand operations and, again, much of it is in the form of free gold.
“Our emphasis now is very much on free gold,” says Remi Filteau, Northgate’s mill superintendant. “Thanks to our gravity circuit, we are collecting 18% of our total gold production in this form; soon it will be 25%.”
The Copper Rand and Portage mines are now producing 2.7 tons of pure gold per year, proclaims Ram Kanwar, general manager of Northgate Mines. Mining at the Copper Rand is mostly directed towards extending the hangingwall zone of orebodies to greater depths and to the northwest. Both cut-and-fill and blast-hole methods are employed; and last year 45,378 tons were mined, grading 0.128 oz gold per ton and 1.55% copper. In May drifting was being carried out:
* on the 2,700-ft level toward the Copper Cliff zone;
* on the 3,600-ft level to see the ore at depth;
* on the 2,400-ft level toward what is called the 65-5 structure (formerly owned by Kerr Addison Mines);
* and on the 3,400-ft level to locate a newly drilled structure (a recent diamond drill hole here showed 29 ft at 3.34% copper and 0.123% gold).
The Copper Rand mine started up back in 1960; the Portage, nine years later. Drifting was being carried out:
* on the 250-ft level to go underneath the Mackenzie Quartz vein, which has high but spotty gold values (in one trench the company encountered a 1 1/2-ft-wide sulphide vein averaging 7.3% copper and 6.10 oz gld per ton);
* on the 2,900-ft level toward the Campbell boundary, where there are some high copper/low gold values in the drill holes;
* and on the 3,650-ft level to explore a newly discovered gold-copper vein. Also, an exploration drift will check the depth of the mineralization at Portage. Kanwar says it could possibly extend as much as 1,000 ft below the 3,650-ft level. Last year 260,549 tons were mined grading 0.152 oz gold per ton.
The company has been spending in the order of $2-$4 million exploring extensions to the two mines. The major objective here has been to extend the life of the mines and possibly justify mill expansion. A major drilling program will be mounted from lake ice over another shear zone in the area where two holes intersected gold values last year. Minova Inc.
Meanwhile gold production from Minova’s Lac Shortt mine in Chapais increased to 64,000 oz from 51,000 oz between 1985 and 1986. Drill-indicated, proven and probable reserves are estimated to be 1.7 million tons grading 0.143 oz gold per ton. The mine entered production in January, 1985, and last year the mill was expanded to increase the concentrator capacity by about 50% to a rate of about 1,237 tons per day. Operating costs have dropped by 10% to $293(C) per oz.
The more historic of Minova’s divisions is, of course, Opemiska which represents one of the earliest exploration attempts in the Lake Chibougamau area. In the 1920s Opemiska Copper Mines became owner of a group of claims on which there was an impressive number of copper showings. A sizeable deposit was proven in the 1930s, but production didn’t start until 1954. A third new deposit was discovered in 1978. While it began production as a copper mine, Opemiska has since become a copper-gold producer owing mainly to depressed copper prices. In 1986 its production of 40,000 oz of gold represented more than 75% of net revenues. Reserves are estimated to be 731,000 tons grading 1.5% copper and 0.084 oz gold per ton; and this represents a 2-year ore supply.
Minnova’s exploration office, also in Chapais, headed by Marc Boisvert, is focusing on structural settings in volcano-sedimentary environments with potential for gold deposits. Activity in the Lac Shortt area is aimed at increasing reserves near the mine, with two major programs now being tested. One is an exploration drift on the 820-ft level to test a gold-bearing structure about 3,280 ft west of the mine workings. However, this drift encountered heavy water inflows and the program was delayed for about two months at the time of our visit.
The other program is a cross-cut on the 1,640-ft level, north into the hangingwall, to test the extension of the orebody below this level. Initial drilling at depth on the main orebody indicates the zone continues at least to a depth of 2,460 ft, or 820 ft below the present workings.
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