Barite and Base Metals

Barite was first noted to occur in the Walton area in 1874-75 by Hugh Fletcher of the Geological Survey of Canada. Interest in barite was rekindled in the late 1930’s as a strategic mineral used for oil production in the Caribbean and South America.

Barite has a unique property of being a very dense rock, almost twice as heavy as granite. It is soft and can easily be ground into a powder. When the powder is mixed with water the resulting fluid is much heavier than the rock that hosts oil deposits. When drilling for oil and gas, if the barite fluid is pumped into the drill hole, the weight of the fluid prevents blow outs.

In 1940 Springer-Sturgeon Gold Mines was exploring the old manganese occurrences of the Walton area. Manganese is a metal important in the manufacturing of steel. The old barite surface occurrence was rediscovered in 1941 and subsequent drilling outlined a barite deposit at surface of 5 to 8 million tonnes. In that year Canadian Industrial Minerals was formed and began mining barite under the product trademark CIMBAR (Photo 226).

A mill built near the former Government wharf was used to crush and refine mud grade barite (Photo 48). Production in the first 3 years was 21,000 tons. In 1944 the mill was enlarged and two concrete silos were built measuring 87 feet high by 35 feet in diameter. In 1955 the Magnet Cove Barium Corporation bought the assets and leased the ore body. This corporation was a subsidiary of Dresser Industries.

By 1957 the pit was 350 feet deep and the decision was made to go underground. A shaft was sunk to the 970 foot level and development drifts were driven at the 350, 520, 690 and 850 foot levels. Further underground development later extended the shaft to the 1700 foot level (Photo 73). The mining method was block caving with drilling done from 8 foot square openings. Holes up to 75 feet long were drilled. Ore was mucked and hauled in 3-4 ton capacity mine cars to an ore pass loading pocket at the shaft. The ore was hoisted to surface at the rate of 100 tons per hour (Photo 76). Ore crushing and grinding was done at the mine site. Barite was shipped over the wharf in Walton in various forms ranging from coarse ore, ground powder and bagged product.

The sulphide ore body was discovered during mine development. The ore contained lead, zinc, silver and copper and over 360,000 tonnes were mined. The average grade was 4.07% lead, 1.96% copper and 418 gm per tonne silver. The average barite grade was over 90%. The sulphide ore was a mineral collectors dream. Museum grade samples of barite, galena, sphalerite, tennantite, proustite, chalcopyrite, bornite, argentite, tetrahedrite ( mineral sample photos) and others are housed in the Nova Scotia Museum of Natural History, Halifax. The mine employed over 150 people at its peak. Difficult mining and diminishing ore resulted in the mine closure in 1978( Photo 81).

Advertisements