Abstract: Coal gangue and coal slime are solid wastes produced in the process of coal washing and mining. A large number of the coal gangue and coal slime will cause a series of environmental and ecological problems. Combustion for power generation is one of the main ways to utilize coal gangue and coal slime efficiently. It is well known that coal gangue and coal slime contain a certain amount of heavy metals,such as Hg,As,Pb,etc. These harmful elements are released in the combustion process,which will cause serious harm to the environment. Therefore,it is of great significance to study the emission characteristics of heavy metals from coal gangue and slime during combustion. In order to investigate the emission characteristics of heavy metals from coal gangue and coal slime burning in O_2/CO_2 atmosphere and air atmosphere,Pingshuo coal gangue and coal slime was used for experiment and the emission characteristics of As,Hg,Pb and Se during combustion in O_2/CO_2 atmosphere( 20%,30% and 40% of O_2 concentration,respectively) and air at different temperatures( 500-1 000 ℃) were studied; and the Hydra-II mercury meter was used to measure the Hg content in coal gangue,coal slime and ash,and the ICP-AES was used to measure As,Pb and Se content in coal gangue,coal slime and ash. The results show that during combustion of coal gangue and coal slime,the ash ratio of coal gangue and slime decreases with the increase of temperature and the O_2 concentration,when the combustion temperature is 500-1 000 ℃ and the O_2 concentration is 20%-40%,the proportion of As,Hg,Pb and Se in the combustion flue gas increases with the increase of temperature and volume fraction of O_2,and the ash content decreases after combustion. The As,Hg and Pb are easier to volatilize into the gas phase with the increase of combustion temperature when coal slime is burned in O_2/CO_2 atmosphere. In addition,when the coal slime burns in air,the ratio of As,Hg and Pb in flue gas is slightly higher than that in flue gas in O_2/CO_2 atmosphere with the O_2 concentration of 20% at the same temperature.