Abstract
Release behavior of mercury was investigated during pyrolysis of coals in the temperature range from 200 to 900℃. Soluble forms of mercury in coal were classified into two fractions by using distilled water and HNO_3 solution. The H_2O soluble of mercury was released at the temperature lower than 300℃, while the HNO_3 soluble of mercury was released in the temperature range from 300℃ to 900℃.