Abstract: Coal combustion is the main way for harmful heavy metal arsenic to enter the atmosphere.It is an effective way to control arsenic emission in-furnace by the adsorption of gaseous arsenic by mineral oxides i. However,coal-fired flue gas contains a large amount of acid gases,including CO_2,HCl,SO_2,etc.,which will combine with mineral oxides,occupy the active site of the sorbents,and thereby reduce the gas-phase arsenic adsorption capacity.In order to understand the effect of acidic gas in flue gas on the adsorption of gaseous arsenic by oxides,some mineral oxides such as Ca O,MgO and Fe_2O_3 were selected as sorbents to carry out gas-phase arsenic adsorption experiments under 700/900 ℃ in simulated flue gas atmosphere.O_2/CO_2 atmosphere and the simulated flue gas containing HCl and SO_2 atmosphere was prepared in a two-stage fixed bed reactor.The arsenic content of the samples was measured by atomic fluorescence spectrometer after extraction with HCl solution,the specific surface area and the pore structure of the adsorbent were analyzed by BET,and the microstructure of the sample was obtained by SEM analysis.The results show that Ca O has the best adsorption effect on gas-phase arsenic,followed by MgO.The arsenic adsorption of Ca O and MgO in the 900 ℃ simulated flue gas is higher than that of 700 ℃,while Fe_2O_3 adsorbs more arsenic at 700 ℃ .In the O_2/CO_2 atmosphere,the amount of arsenic adsorbed by MgO and Ca O is less than that of simulated flue gas,while the capacity of gaseous arsenic adsorbed by Fe_2O_3 is higher than that of simulated flue gas.The effect of acidic gas on arsenic adsorption by oxides is related to the temperature and types of oxides.The O_2/CO_2 atmosphere inhibits the adsorption of gas-phase arsenic by Ca O and MgO,and it promotes Fe_2O_3.HCl in simulated flue gas inhibits the adsorption of gas-phase arsenic by Ca O,and it inhibits the adsorption of gaseous arsenic by MgO and Fe_2O_3 at 700 ℃ and promotes at 900 ℃ .SO_2 in the flue gas inhibites Ca O and MgO,but has no significant effect on Fe_2O_3.CaO,MgO and Fe_2O_3 are mainly chemisorbed by gas-phase arsenic,Fe_2O_3 has the largest specific surface area,but the adsorption is the weakest.