不同烘干温度下褐煤可磨性指数研究

Study on grindability index of lignite at different drying temperatures

摘要: 为了探索烘干温度对褐煤可磨性指数(HGI)的影响,选取不同地区的褐煤,将其在不同温度下烘干,测定相应的可磨性指数(HGI),并通过失重率、热解试验以及扫描电镜试验,分析了HGI值的变化原因。结果表明:褐煤在热解中的水分蒸发阶段具有较大失重速率,HGI值在不同烘干温度下变化较大;随着烘干温度的升高、水分的析出,褐煤孔隙结构会发生不同程度变化,不同的孔隙分布是煤样HGI值随烘干温度改变而发生不同程度改变的根本原因。该研究结果可为电厂褐煤研磨过程中的一次风调温提供参考。

Abstract: The effect of drying temperature on Hardgrove grindability index(HGI) of lignite is explored with the lignite selected from different regions, and the factors causing the change of HGI are investigated through test on rate of weight loss and thermal discomposition and by scanning electronic microscopic analysis. Test results show that the HGI varies widely due to great rate of loss of weight at the water evaporation stage during the pyrolysic process at different drying temperatures; with the rise of drying temperature and water precipitation, the pores of lignite tend to undergo a structural change to varying extent; and the variation of pore distributions is the root cause leading to the change of HGI at different drying temperatures.