Photo taken on June 15, 2006 shows the salt field of the Qairhan Salt Lake, about 60 kilometers north of Golmud, northwest China's Qinghai Province. Qairhan, the largest salt lake in China, covers an area of 5,800 square kilometers. It has a total reserves of 60 billion tons of minerals including potassium, sodium, magnesium, lithium. [Xinhua Photo]

Photo taken on June 15, 2006 shows salt crystals at the Qairhan Salt Lake, about 60 kilometers north of Golmud, northwest China's Qinghai Province. Qairhan, the largest salt lake in China, covers an area of 5,800 square kilometers. It has a total reserves of 60 billion tons of minerals including potassium, sodium, magnesium, lithium. [Xinhua Photo]

Photo taken on June 15, 2006 shows a slat extraction ship at the Qairhan Salt Lake, about 60 kilometers north of Golmud, northwest China's Qinghai Province. Qairhan, the largest salt lake in China, covers an area of 5,800 square kilometers. [Xinhua Photo]