Abstract: Zhundong coalfield is the largest integrated basin in China. Combined with the characteristics of medium and high water content,medium and high volatile matter,low contents of sulfur,trace element,and low cost mining,medium calorific value and good reaction activity,which is a large-scale coal chemical industry and coal electrical co production high-quality raw material.However,the high content of Na and Ca in Zhundong coal affects the normal operation of the boiler,which limits the combustion and utilization of Zhundong high sodium coal. To investigate the combustion and slagging characteristics of Zhundong coal and its mixture,two raw coal called Zhundong coal(ZD) and Wudong coal(WD) were collected from Wuhuaiwan power plant. The combustion characteristics of ZD coal and mixed coals were studied using thermogravimetric analyzer,and the change rule of coal ash characteristics under response ratio was analyzed.The results show that there are two characteristic peaks for blendings of Zhundong and Wudong coals. With the increase of ZD coal blending ratio,TD-DTG curves of blended coal combustion move to the low temperature area,and the characteristic peak of DTG curve is more obvious.The characteristic temperature and the ash fusion temperature of blended coals gradually decrease,while the maximum combustion rate and comprehensive combustion characteristic index first decrease and then increase,and the fusion temperature of blended coal ash gradually decreases.ZD coal has higher alkali oxide and lower acid oxide content than WD coal,and blending with high ratio zhundong coal has high contents of SO_3,CaO and Na_2O and more serious ash-related problems;However,some indexes can not accurately predict the slagging strength,such as Zhundong coal silicon aluminum ratio is 1.67,and Wudong coal silicon aluminum ratio is 3.02.Judging slagging tendency based on silicon aluminum ratio is not consistent with the fact;In addition,when the CaO content in coal is more than 30%,the ash melting temperature will increase,which is the reason why Zhundong coal has higher ash melting temperature than Wudong coal.With the increase of the proportion of Zhundong coal,the melting temperature of blended coal ash decreased obviously. The indexes of combustion slagging and fouling tendency are mainly based on the composition of coal ash and the melting temperature of coal ash.Based on the test results of the former prediction indexes of slagging and fouling,it is concluded that the alkali acid ratio based on the ash composition and the characteristic temperature difference(FT-DT) based on the ash melting temperature are the ideal indexes for judging the slagging and fouling tendency of Zhundong coal and its blended coal.