Arsenic volatilization characteristics of SJS bituminous coal were carried out on the high-temperature tube furnace from 600℃ to 1400℃ at different oxy-fuel atmospheres. Combined with FTIR analysis and thermodynamic analysis

and taking air condition into consideration

the effects of O2

CO2 and temperature on arsenic volatilization were studied. Results showed that the releasing proportion of arsenic increased with increasing temperature both in oxy-fuel and air combustion. Two arsenic mass loss peaks were observed at ＜900℃ and > 900℃ stages

separately. At temperature lower than 900℃ oxygen content was the major fact. The more O2 ratio

the larger volatile proportion of arsenic. But at the same O2 ratio condition

the higher CO2 concentration brought down the emission of arsenic and thus the volatile proportion was decreased. At temperature higher than 900℃ the content of carbon dioxide was the major fact

The higher CO2 concentration in oxy-fuel atmosphere hindered heat transfer

and thus higher temperature was needed for the decomposition of arsenates under the same conditions

which led to the delay of the intensive emission of arsenic compared to air condition. Besides

high CO2 content in oxy-fuel condition resulted in the reductive atmosphere around coal particles

which caused arsenic compounds with high chemical valence being reduced to compounds with lower chemical valence

while the arsenic compounds with lower chemical valence were unstable and their fast decomposition led to the higher mass loss rate of arsenic in oxy-fuel condition than to the air condition.