The South Pole: Mining Antarctica

Can it really be done? It’s well known that mineral extraction in Antarctica would be both dangerous and prohibitively expensive, made difficult by long distances and severe weather (see Climate). Even with the right technology, most of the mineral deposits are relatively difficult to reach. Even small scientific bases are difficult to keep sustained – an example would be the British base at Halley Bay, which was jeopardized when ships failed to reach it during the winters of 2002 and 2003.

In the 1980s, a plan for the Dufek Platinum Mine (DPM) was drawn up. The proposed mine would extract platinum from the Dufek Formation, south of the Filchner-Ronne Ice Shelf, about 600 km (400 miles) from the Weddell Sea (see Ice Shelves). With about 95% of the deposit under the icecap, the mine was specifically designed for the harsh climate, thick ice cover, and permafrost (see Continental Ice).

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Possible Antarctic mines have been modeled on the Polaris lead-zinc mine in Nunavut, Canada

Its design was based mainly on the Polaris Mine, the most northerly mine in the world at 77 ºN. Polaris was opened in 1981, and extracted lead and zinc on Little Cornwallis Island in Canada’s Arctic until its closure in 2002. Ore was mined and crushed underground, and then transported 1100 m (0.7 miles) to the surface where it was milled. The facility featured a mile-long gravel runway that could handle aircraft as large as the Boeing 727, and a dock facility from which the ore was shipped to smelters in Europe. The 250 employees lived in a company town year-round. The entire facility was prefabricated in Quebec and towed up north by barge, and assembled on the spot.

The greatest single challenge at DPM would be transportation, which would be facilitated through a combination of sea and air. After being extracted and produced, the ore concentrate would first flown by helicopter to a nearby gravel airstrip. There, heavy cargo planes would transport the concentrate to the shore of the Weddell Sea, 600 km (400 miles) away. From there, cargo vessels would ship the concentrate to smelters. Like Polaris, the mine would only be accessible for about 6 weeks during the height of the summer, from late December to early February. No flight would be empty; on the way to the mine, planes would carry the supplies necessary to support the mine for the next 9 months of inaccessibility. Each flight would cost a total of $4,000 per hour.

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The Polaris mine was the world's northernmost mine, located at 77 ºN

The next main challenge would be water and power. A water supply would be secured by drilling 1000 m (3300 ft) through the ice to water beneath the shelf, which would be transported up to the mine by heavy-duty pumps. The electricity would be provided by 2 diesel generators, with a total installed power of 9200 kW, operating with crude oil or natural gas fuel. At Polaris, mine tailings were discharged conveniently in a nearby lake; plans for DPM make no mention of how waste would be hypothetically dealt with.

The high ice content of the rock would require keeping the temperature in the mine well below freezing point – usually lower than -10 ºC (14 ºF) – so that the permafrost remains stable. Such a system requires complex ventilation. During the unusually warm Arctic summer of 1983, the partial melting of the permafrost at Polaris caused the mine to temporarily close. Refrigeration units were installed to prevent such problems in the future.

Permafrost actually makes underground mining much easier and more efficient. Without the permafrost, ice-filled cracks in the rock would melt and drain into the mine, as would seawater. In higher-temperature mines, a lot of ore is wasted because pillars of rock must be left to support the roofs of excavated tunnels. In the permafrost, excavated backfill is frozen and can be used to support the tunnel instead, allowing more ore to be mined. The permafrost, in fact, made Polaris one of the lowest-cost lead-zinc mines in the world. The Polaris case suggests that Antarctic mining may not be as difficult as once imagined.