Joe Mann’s performance beating earlier predictions

With deepening of the No. 2 shaft to 3,000 ft. planned to get under way early in 1992, the Joe Mann gold-copper mine of Campbell Resources (TSE) will be well on the road to becoming a 100,000-oz.-per-year producer.

The mine, about 40 miles south of here, turned out 67,489 oz. (and 1.3 million lb. copper) in 1990 at a cash cost of US$277 per oz. gold. Output for 1991 was projected to be 75,000 oz. but that prediction may turn out to be low; after five months of operation, production totalled 35,400 oz. at a cost of US$270.

The Northern Miner recently toured the narrow-vein (pinching and swelling) mine — with visible gold — which is currently operating with a single shaft and small rail cars. In (and out) of production in the 1950s and again in the early 1970s, the mine has been in steady operation since 1987.

The Joe Mann mine, officially operated by Campbell’s wholly owned subsidiary Ressources du Lac Meston, provides jobs for 241 persons, including 169 underground workers. General mine manager is Karol Mikulash, who joined Campbell in 1990 and who previously worked in this area with Minnova Inc. General superintendent is John Maxwell, who also worked for Minnova in this area.

The original deposit was discovered in 1950. A 3-compartment exploration shaft was sunk, and by 1960 about 686,000 tons averaging 0.22 oz. gold per ton had been mined and milled. Fire in 1961 destroyed the surface plant. A second attempt to open the mine was short-lived in the early 1970s because of rising costs and poor recoveries.

A new owner, Meston, dewatered the shaft in 1980 but the project did not re-enter production. In 1983, Campbell agreed to acquire a minority position in Meston and undertook an exploration program. In December, 1987, Campbell acquired a 100% interest in Meston.

In 1985, an underground drifting and drilling program was initiated, with successful results. The mine was started up for a third time in April, 1987, with proven and probable reserves of 910,000 tons grading 0.22 oz. During eight months of operation in 1987, the mine yielded 134,500 tons of material grading 0.19 oz. gold and 0.31% copper. Total gold output that year was about 22,100 oz.

Exploration work since the 1987 startup both east and west of the shaft, from surface and underground, has resulted in a gradual increase of the original reserve base. At the end of May of this year, total reserves (all classes) stood at 3.4 million tons averaging 0.27 oz. gold, 0.32% copper and 0.16 oz. silver per ton.

In early 1989, Campbell began an expansion program which saw a second shaft sunk to 2,050 ft. Underground drilling last year, below the 1,650-ft. level, confirmed ore-grade material to 2,700 ft.; the 11 holes averaged 0.26 oz. over 6 ft. (true width). At the company’s annual meeting this year, President John Kearney said a decision has been made to deepen the shaft to 3,000 ft. beginning in 1992. The job (deepening and related development work) is expected to take 18 months to complete and cost $10-11 million.

Although the No. 2 shaft is ready for use, it remains idle, pending a startup of the deepening program. Raymond Gauthier, general mine foreman, said the No. 2 shaft will be placed into service during a 2-week period this summer to allow for routine maintenance of the No. 1 shaft.

Following a review of underground mining conditions last year, Campbell decided to alter the Joe Mann mining strategy: the longhole method is now used only for stopes wider than six feet, with the remaining units mined by the shrinkage method. Increased tonnage and a higher grade have resulted from the change. The drifts are driven 8.5 ft. high and 8 ft. wide in the ore zone and 8.5 ft. high and 9 ft. wide in waste when driving footwall and haulage ways.

At the time of the June visit, Joe Mann was hoisting about 1,400 tons of ore per day, plus another 400 tons of waste. Since the beginning of 1991, the material has been derived from nine shrinkage stopes, five longhole stopes, nine drifts, three raises and one sub-drift. The lowest current production level is 1,600 ft.

The ore is trammed on rail with mine cars. Crushed underground to four inches (the crusher sits at the 1,680-ft. level), the ore is hoisted to surface and trucked about 40 miles to the Camchib mill, just south of Chibougamau. (A 700-ton-per-day mill at the Joe Mann site is not currently in service.)

Only a few years ago, Campbell operated four gold-copper mines in the Chibougamau area: Joe Mann, Cedar Bay, S-3 and Henderson 2. Today, only the Joe Mann is in operation.

At the Camchib flotation mill (which originally served an on-site mine), the ore is crushed and ground before it enters a gravity circuit. Coarse gold is cleaned on a shaker table and the free gold is stored in the vault. The mill’s flotation circuit consists of 2-stage roughing cells, double-stage cleaner cells, a scavenger cell combined with a retreater and regrind circuit. The cyanidation circuit treats 43% of the flotation circuit tailings and the pyrite concentrate from the regrind circuit.

The mill produces its own bricks containing about 90% gold, mill superintendent Germain Naud said. The copper concentrate produced is shipped to the Horne smelter at Rouyn-Noranda, Que. The copper concentrate side of the mill operates with two 5-day-per-week shifts, while the cyanidation process operates on a 24-hour, 7-day-per-week basis.