Abstract: Blended coals combustion is an effective method to control arsenic emissions from coal combustion,but due to the lack of relevant coal blending models,the application of this technology is limited. Based on the mechanism of arsenic volatilization and release in coal combustion process,a coal blending model was proposed,in which arsenic release index P was used to describe arsenic release characteristics during coal combustion. The ash content of coal,the content of mineral elements in each ash,the fixed coefficient of arsenic of each mineral element,and the arsenic content in coal were considered in this model. The results demonstrate that with the increase of coal ash fixation coefficient from 23. 12 to 50. 90,the arsenic adsorption capacity in coal ash increases from 3. 39 mg/g to 6.14 mg/g. The fixed rates of arsenic decreases with the increase of the release index P,and with the increase of temperature,the correlation increases from 0.67 at 900 ℃ to 0.86 at 1 300 ℃.According to the P value,the coals are screened for blending combustion. When the difference in P value of blended coals is large,the low P value coal can not only reduce the arsenic content in the blended coals,but also promote the enrichment of arsenic in the high P value coal,which is up to 77.14%. However,when the P value difference of the blended coal is small,the combustion of blended coal with low P value will promote the release of arsenic. This model can be used to screen coal types well and provide a new idea to control the emission of trace elements such as arsenic by blended coals combustion.