Effect Of Coal Ash Composition And Mineral Composition On Ash Fusibility Of Huainan Coal

The ash fusion temperation is affectd directly by the coal ash mineral ,and mineral composition change on the condition of high temperature ,thus mineral behavior on the condition of high temperature is studied by X-ray diffraction (XRD) and infrared spectrum (IR),and it is important to study the effect of mineral composition on ash fusion.Twenty-three kinds of Huainan coal and three kinds of coal of other areas are selected in the experiment, the relation between chemical composition and ash fusion temperature is studied in reducing atmosphere;The relation between the infrared spectrum and chemical composition of ash and the relation between infrared spectrum and ash fusion temperature are discussed;Effect of mineral composition on ash fusion temperature are determined by X-ray diffraction (XRD) and infrared spectrum (IR). Some primary results are obtained as follows: 1 The relation between single chemical composition and ash fusion temperature isunclear.2 After adding fluxes ADC, ADF and ADN,the OH stretching vibration at 3644cm^-1 on the infrared spectrum of coal ash disappears, and appears at 3740cm^-1. The OH stretching vibration at 2922 and 2853cm^-1,H₂O stretching vibration at 3447cm^-1, and OH bend stretching vibration at 1397cm^-1 and 1630cm^-1 weaken to some extent. After adding fluxes ADN and ADF, the wave at 500-400cm^-1 on the infrared spectrum of coal ash moves to high-frequency.The hematite wave at 564cm^-1 on the infrared spectrum of coal strengthes gradually along with the adding of ADF. The wave at 1200⁹50cm^-1 on the infrared spectrum of coal moves to high-frequency gradually,and the anhydrite wave at 700-400cm^-1 on the infrared spectrum of coal strengthes obviously along with the adding of ADC. 3 When the content of CaO reduces to less than 5%, linearity relativity between ash fluid temperature and Si-O-Si flex vibration at 1100-1050cm^-1 of infrared spectrum of ash exists. The relation between the infrared spectrum and fusion temperature of ash after adding Fe₂O₃ as the additive are investigated. The result shows that linearity relativity between the transmittance ratio of hematite's typical absorption band at 564 cm^-1 to Si-O bend-vibration absorption band at 476 cm^-1 and ash fluid temperature exists clearly after adding Fe₂O₃ as the additive.4 The main mineral of Huainan coal ash are quartz,kaolintie,hematite,anhydrite and calcite.The main cause resulting in the change of ash fusion temperature is the mineral transformation at high temperature.MuUite results in the increase of ash fusion temperature.Quartz can react with anorthite and hematite at high temperature to generate a crystal with low fusion point,which results in the decrease of ash melting temperature.