Korea has found rare earths reserves in the North Chungcheong and Gangwon provinces, with a sufficient supply for the next 50 years, a state-run think tank said Wednesday.

The deposit in Chungju, 147 kilometers southeast of Seoul, contains 71,500 metric tons of rare earths. The one in Hongcheon in the country’s east has about 76,000 metric tons, the Korea Institute of Geoscience and Mineral Resources estimated.

Rare earth metals are a group of 17 metallic elements with similar properties and structures that are essential in manufacturing high-technology applications including batteries, hybrid cars, lasers and clean energy products. Despite their name, they are relatively common in the earth’s crust but not often found in economically exploitable form due to their geochemical properties.

The discovery would help curb the country’s reliance on overseas supplies, experts said. Korea imports almost all its mineral needs, bringing in 2,655 metric tons of rare earths in 2009.

Tensions linger over China’s near-monopoly in the global rare earths market since it curtailed its exports quota by 40 percent last year from 2009 levels, which pushed up the minerals prices sharply. Countries led by the U.S. and Japan have been urging China to relax its export constraints.

Daejeon-based KIGAM said it has been testing and analyzing sample ores in the country’s 11 potential reserves since last June to see whether they hold such mineral veins. It plans to further study the two areas to nail down the exact quantity of rare earths.

“The lodes in Chungju and Hongcheon also contain a considerable amount of iron ore, and niobium and tantalum, key materials for heat-resistant alloys,” a KIGAM official said, adding that production will be commercially viable.

By Shin Hyon-hee (heeshin@heraldcorp.com)