Canada Talc oldest producer in Ontario

If one were asked to name the oldest continuously producing mine in Ontario, the prolific gold mines of Timmins and Kirkland Lake may spring to mind. Few would guess that the province’s oldest mine is to be found in the small, rural community of Madoc, yet alone that it is a talc-producer.

The Canada Talc mine, formed in 1937 through the merger of the Henderson and Conley Talc mines, has a history that reaches back into the late 19th century, when Ontario’s mining industry was just beginning. The Northern Miner recently visited the eastern Ontario property.

Talc was discovered in 1881 in the area on a farm belonging to Christopher Henderson. Fifteen years later, the Henderson mine was opened. The property was mined via open pit until 1908, after which time underground mining was carried out on seven levels to a depth of 443 ft., until 1965. An extension of the Henderson orebody was discovered in 1911 on the adjacent Conley farm, to the northeast. From 1912 to 1935, two shafts were sunk and the Conley mine was developed to a depth of 470 ft. on eight levels. In 1937, the two properties were merged and they have been operated as one mine ever since, employing about 30 people. In 1981, Canada Talc was purchased by Barmin of Waterdown, Ont., a private company with activities in the mineral products sector.

The talc occurs as hydrothermal replacement bodies in dolomitic marble. Most of the talc is hosted in two zones: the Henderson and the East. Henderson is a steeply dipping, east-west-trending tabular sheet of highly pure white talc. The zone is 10 to 60 ft. wide, 900 to 1000 ft. long and averages 50-60% talc. Impurities such as dolomite, non-asbestiform tremolite, mica and pyrite make up the remainder of the zone. Reserves are just over 900,000 tons of talcose ore (“talcose” denotes ore that is not pure talc). The East zone, delineated by diamond drilling in the early 1980s, is 20 to 80 ft. wide and has an indicated strike length of 1,200 ft. It is similar to Henderson except that it averages only about 35% talc. Reserves are about 2.4 million tons of talcose ore.

Both orebodies are cut by fault zones up to 10 ft. wide and late mafic dykes termed “madocites.” The faults and dykes are a constant source of water in the mine, and General Manager Robert Kirkwood told The Northern Miner that up to 850,000 gallons per day are pumped from underground. Although the water, which flows into a creek and then to Moira Lake, contains no chemicals, it is tested regularly, Kirkwood said.

Talc production totals 1800 to 2000 tons per month, all of which comes from the western portion of the Henderson zone. (The eastern portion was previously mined from the old Conley mine.) Limited mining was carried out on the East zone by open pit between 1982 and 1986, but, to be economic today, the ore would require upgrading by flotation.

Access to the Henderson zone is provided through the Conley #3 shaft which was sunk in 1935 to develop a newly discovered orebody. The old Conley shafts are no longer used and have therefore been sealed and the Henderson #4 shaft is used only for ventilation and as an emergency exit.

The #3 shaft is 611 ft. deep and serves three levels: No.1 at 270 ft.; No.2 at 370 ft.; and No.3 at 542 ft. Most of the mining occurs below the third level, with access provided by a 10×12-ft. ramp that extends down to 723 ft. Six to eight people work underground where most of the ore is mined using an induced caving method. With this technique, all development work is carried out in the hangingwall with draw points established through the ore zone every 35 ft., explained Mine Engineer Rick Lockstein. A drift is then driven along the hangingwall contact, linking up several of the draw points. The ore is blasted using a longhole technique, causing it to cave into the draw points. It is pulled from the draw points and conveyed in 3 to 5-ton trucks to a grizzly rock-breaker on the third level.

Where ground conditions permit, ore is mined using a shrinkage method, Lockstein added.

Once hoisted to the surface, the ore is sorted by color and then crushed. The whiter, purer talc ore is then processed and bagged at the mine site while the darker, less pure ore is sent to the company’s plant in Marmora for further processing.

Canada Talc produces a wide range of talc-rich products which are used as fillers in paints, plastics, ceramics and paper. About 80% of its products are exported to the U.S., mainly for use in plastics.

Robert Outwater, technical service manager, said production costs, including mining and milling, are about $110 to $115 per ton and that the average product sells for about $160 per ton.

Total production since 1896 is estimated at 1.2 million tons and is valued at about $48 million.

With annual sales of $3-4 million and a healthy profit margin, it comes as no surprise that several major companies, such as Lac Minerals (TSE), Dickenson Mines (TSE), Cambior (TSE) and Metall Mining (TSE), have evaluated the deposit for possible acquisition or joint venture.

In 1990, Nanisivik Mines, a subsidiary of Conwest Exploration (TSE), carried out a 10,000-ft. drill program to delineate additional reserves. Although the program proved up new reserves, they were not sufficient to warrant participation, Nanisivik decided.

Canada Talc also produces about 10,000 tons of white dolomite from a surface pit on the property. The dolomite is crushed for decorative stone or powdered for field stripe which is used for marking sports fields.

Although reserves are sufficient for several years of production, Kirkwood would like to carry out more development work and prove up additional reserves. On the product side, the company continues to spend money on marketing and research and is looking at installing a beneficiation plant to produce higher-quality talc products.