Abstract: In view of the increasingly serious pollution problem of cement industry and the increasingly strict requirements for desulfurization wastewater discharge，this study proposed to use the waste heat of clinker of grate cooler to evaporate the desulfurization wastewater of cement furnace.This method realized zero discharge.The effects of atomization and evaporation of desulfurization wastewater at the grate cooler on flue gas temperature，NOx concentration，ammonia escape concentration and flue gas dust mass concentration were studied by experiments on a cement furnace production line with a clinker output of 6000t/d and mixed with dry sludge.The experiment results show that NH3 produced after the evaporation of desulfurization wastewater enters the decomposition furnace with the tertiary air and reacts with NOx in the furnace，and this process is conducive to reducing the ammonia injection of SNCR (selective non catalytic reduction) system.Under the full load of the furnace and maintaining the stable working condition of SNCR system and dry sludge mixing，the NOx emission concentration gradually decreases with the increase of desulfurization wastewater injection.When the injection amount of wastewater is 5.5m3/h，the NOx concentration reaches the lowest value.The evaporation of desulfurization wastewater at the high temperature section of grate cooler will reduce the temperature of tertiary air and secondary air，and inhibit the generation of thermal NOx in decomposition furnace.The evaporation of desulfurization wastewater in high temperature environment will produce HCl and SO2 gas，which has a certain impact on the efficiency of wet desulfurization.

Key words: desulfurization wastewater, atomization and evaporation, zero discharge, cement furnace, mixed with dry sludge, NOx