Abstract: A large amount of flue gas is emitted from the coke production process,and sulfur dioxide(SO_2) and nitrogen oxides(NO_x) in the flue gas cause environmental pollution.With the increasingly strict air pollutant emission standard of coking industry,in order to solve the air pollution of SO_2 and NO_x from coke oven flue gas,the combined desulfurization and denitrification experiments of coke oven flue gas in the self-made bubbling reactor were carried out with steel slag as absorbent.The effects of reaction temperature,concentration of steelmaking slag slurry,gas flow,SO_2 content as well as NO content on SO_2 and NO removal efficiency were investigated,and the optimal operating condition was obtained.Results show that the increase in temperature will reduce the reaction rate of NO oxidation,resulting in the decrease in the concentration of NO_2 produced,thereby reducing the denitration efficiency.The increase of slurry concentration will increase the p H value of the slurry and promote NO removal;the increase of the flue gas flow,that is,the decrease of the residence time will reduce the gas-liquid contact time,resulting in the decrease in the desulfurization and denitration efficiency;when the optimal operating condition is reaction temperature of 30℃,steelmaking slag slurry concentration of 8% and gas flow of 400 m L/min,the denitrification efficiency can reach 50.7% and desulphurization efficiency is above 95%.Research on the mechanism of simultaneous desulfurization and denitration of steel slag show that:the OH~-dissolved from steel slag can keep the slurry alkaline and has a high p H buffering capacity,which is beneficial to the removal of SO_2 and NO_x;NO reacts with O_2 to form NO_2,and NO_2 reacts with OH~-to form NO_2~- and NO_3~-;NO_2 reacts with NO to generate N_2O_3,which is soluble in water,and N_2O_3 reacts with OH~-to generate NO_2~-,thereby achieving NO_xremoval.NO is oxidized to NO_2 through the gas-phase pre-oxidation method.The results NO_2 and N_2O_3generated by the reaction of NO_2 with NO can be absorbed efficiently by steelmaking slag slurry,thereby reaching the general or ultra-low emission standard of NO_x,and achieving industrial application for simultaneous desulfurization and denitration using steelmaking slag.