Rio Tinto Group, the world's second- largest uranium producer, plans to boost output from the Rossing mine in Namibia by 38 percent and extend its life as Asian countries plan more nuclear reactors.

Rio will dig a second pit and use new processing techniques to increase annual uranium-oxide production to 5,500 metric tons in 2012, from the 4,000 tons this year, Rossing Managing Director Mike Leech said today. The London-based company intends to operate the mine beyond 2021, he said.

China and India are constructing nuclear power stations after coal, oil and gas rose to records. India plans to add 40,000 megawatts of nuclear capacity by 2020. The country said last month it would place orders for as much as 2,000 tons of uranium before the year-end to ensure supplies.

Rossing, which supplies about 7.6 percent of the world's uranium, is located 290 kilometers (180 miles) from Windhoek, the Namibian capital. It produced 3,046 tons of uranium oxide in 2007. Rio may expand existing processing plants or use so-called heap-leaching technology to boost output, Leech said in a presentation at the mine.

Heap leaching uses sulfuric acid to extract metal from ore. Trials are under way and an investment decision will be made in May. The first production using the process on stockpiled ore may come in the first quarter of 2011 and add as much as 1,000 tons of annual output, Leech said.

Rossing is 69 percent owned by Rio. Namibia is Africa's second-biggest producer of the nuclear fuel, after Niger. – China Mining