Distribution of uranium in the main coalfields of China

摘要

In China, the world's largest producer of coal, the mean value of uranium in coal is 3 mg/kg, which is near the published value for uranium in coal in the United States and the world coal average. There are a few examples of Chinese coal that have exceptionally high concentrations of uranium and may be considered as a uranium source. In Hubei province in southern China a special type of stone-coal from the lower Silurian has a uranium concentration of 180 to 280 mg/kg in the coal ash. A few samples from Jurassic coal in Xinjiang of northwest China have more than 200 mg/kg uranium. The uranium in coal is mainly associated with organic matter in low rank coal. In high rank coal the uranium probably occurs in the minerals. In nature, the uranium-rich deposit is rare, and usually small in scale. Uranium abundance and occurrence in different places and strata, especially in coal stone in the South China and in marine shale, have potential hazards on the environment.