Study On Ash Components And Fusing Regularity Of Coal In Different Geological Time

Slagging on coal-fired boiler in thermal power plant is widespread. It is the chief factor which does harm to the safety and economy of boiler. In our country, slagging is prominent for there are many kinds of coals and their characteristics are very different. The qualities of coals are the primary factor causing the slagging problem. Therefore, the characteristics of coal-ash fusibility are very important for predicting the slagging trend.Different coal has different mineral components. In the heating process, there are lots of chemical reactions occurring in minerals and between different minerals. Low temperature eutectic phenomenon may be occurring between different kinds of minerals simultaneously. Thus, the ash fusion characteristics are very complex. As the forming ages are different, coals can be divided into different groups according to the geological time. Coals in different geological time always have different internal mineral components for the generated environments are not the alike. Also, these differences affect coal-ash fusion characters. Furthermore, in mining process, some external minerals will be brought into coals inevitably, since the existence of gangue in the roof of the coal seam, the floor of the coal seam and the interspatial gangue layer. The external minerals in different geological time cause different influences on coal-ash fusion characters because of the diversities of geological conditions.In this paper, some typical kinds of coals of different generated age are selected to be analyzed. The original mineral components, external minerals and the characteristics of melting point are concluded according to different geological time. Using the methods of thermogravimetry and differential scanning calorimetry (TG-DSC), study the regularities of fusion characters in different geological time by analyzing the performance of TG-DSC curves through heating process. Make qualitative analysis on these selected coals, coal-ashes and high-temperature coal-ashes with X-ray diffraction (XRD). Study the diversities of different geological-time coals and coal-ash particularly. Predict the slagging trend by observing the characteristic of high temperature ashes. It would give some reference for the selection of coals to avoid slagging.