THERMAL DESORPTION EXPERIMENT OF POLYCYCLIC AROMATIC HYDROCARBONS CONTAMINATED SOIL USED AS CEMENT RAW MEAL

Taking polluted soil surrounding a Shougang coking workshop as sample object，TG analysis，and thermal analysis on raw soil and cement raw mill experiments were conducted，the results showed that: The polluted soil contained various organic pollutants of PAHs，and the total concentration of PAHs was about 156. 39 mg /kg． Weight loss of the soil contaminated by PAHs could be divided into three stages at 850 ℃: Water losing stage，organic matter decomposition stage， and inorganic carbonate decomposition stage． With the increase of heating temperature，removal rate of total PAHs in raw soil went up． Using polluted soil as cement siliceous raw material，except naphthalene，acenaphthene，two hydrogen acenaphthene and anthracene，other organic compounds of PAHs had residues at 300 ℃ and small amounts of phenanthrene had residue at 600 ℃，showing that cement raw material had certain adsorption on PAHs pollutants． Therefore，when polluted soil of PAHs was coprocessed into the cement kiln，the content of pollutants in flue gas volatilization should be focused on．