煤泥微观结构及燃烧特性实验研究

Experimental Study on Microstructure and Combustion Characteristics of Coal Slime

为了掌握煤泥微观结构和燃烧特性,采用扫描电子显微镜、傅里叶红外光谱测试及热重分析的实验方法,研究了彬长矿区煤泥的表观特征、官能团种类及燃烧特性。采用动力学分析方法,得到了不同升温速率的动力学参数变化规律。结果表明:煤炭在洗选过程中分离出的矿物杂质以堆积或与煤互相渗透为一体的形式赋存于煤泥结构中,隔绝了煤泥与空气接触,影响了其表面性质;煤泥中存在大量矿物质基团,这是煤泥难以利用的重要原因之一;煤泥在不同升温速率下的氧化过程呈分阶段特性,且随着升温速率的增加,TG-DTG-DSC曲线均呈现滞后现象。高升温速率延长了煤泥热解燃烧的反应过程,使得煤泥的特征温度、着火特性指数Ci和燃烧特性指数S随升温速率的增加呈现增大趋势。煤泥的活化能E和指前因子A与升温速率呈负相关,但效果并不明显。研究结果对煤泥资源化利用具有重要意义。

In order to master the microstructure and combustion characteristics of coal slime,the apparent characteristics,functional groups and combustion characteristics of coal slime in Binchang mining area were studied by means of scanning electron microscopy,Fourier infrared spectroscopy and thermogravimetric analysis.Kinetics analysis method was used to obtain the change rule of kinetics parameters for different heating rates.The results show that the mineral impurities separated in the process of washing and separation of coal are deposited or interpenetrated with coal,and occur in the structure of coal slime,which insulates the contact between coal slime and air and affects its surface properties.There are a lot of mineral groups in the coal slime,which is one of the important reasons why the coal slime is difficult to use.At different heating rate,the oxidation process of coal slime shows a stage characteristic,and with the increase of heating rate,the TG-DTG-DSC curve shows lag phenomenon.The heating rate is extremely fast,which leads to the prolongation of the combustion reaction process of coal slime,and its characteristic temperature,ignition characteristic index Ci and combustion characteristic index S all show an increasing trend with the increase of heating rate.The activation energy E and pre-finger factor A of coal slime are negatively correlated with the heating rate,but the effect is not obvious.It is of great theoretical significance for coal slime resource utilization.