Fluorine content and distribution pattern in Chinese coals

About 300 coal samples were collected to study the fluorine content and distribution pattern in Chinese coals in different coal basins and geologic periods. The Permo-Carboniferous and Jurassic coals in the North China Plate and Northwest China account for nearly 90% of Chinese coals and their fluorine content is 20-300 mg/kg, mostly about 50-100 mg/kg. Fluorine content of Permo-Carboniferous coals, the main steam coals in China, is 50-300 mg/kg; Jurassic coals 20-70 mg/kg. There are great differences in fluorine content of Late Permian coals in Southwest China (50-3000 mg/kg), which accounts for only 7% of Chinese coals. According to the proportions of the coals with different fluorine content in Chinese coal resources, the average fluorine content of Chinese coals is about 82 mg/kg, which is close to the world average (80 mg/kg). Most Chinese coals are low-fluorine coals (