Study On Phase Trasition And Mechanism Of Coal Ash

Slagging and fusibility have always been the most serious problem that affet the normal production of the coal burned boiler.This threat the security and economy of the coal burned power plants. Many domestic and foreign researchers do a lot of work.They add differenet mineral into coal ash to reveal the theory of the boiler slagging and the coal ash fusibiliy of some mineral.In this paper, three kinds of coal ash Zhangcun,Jinxikuang,Yuenan and three kinds of fluxes CaCO₃,Na₂CO₃ and FeS₂ were selected, then the fluxes were separately added into the ash. The paper do a lot of experiments to study the fusion mechanism of six coal ash with thermal analysis, X-ray diffraction and Scanning electron microscope.The results of this paper are as following.Studied the fusibility of six coal ash with thermogravimetry and differential thermal analysis.Analyzed the reason of change on the TG,DTG,DTA,DDTA curves. Phase trasition characteristic temperature point at 400, 800,1100 and 1250 can be obtained from TG, DTG, DTA and DDTA curves, respectively.The result from XRD experiment shows that, cosolvent tends to react with minerals in the ash and the products that are common solution matters with low melting point decrease the melting temperature of ash.From result of FESEM,flux will affect fusibility of coal ash.This will make fusibility obviously. Results from XRD and FESEM methods show that, it is available to obtain melting temperature and temperature section within which phase change occurs by thermo gravimetric method.