脱水褐煤中矿物质对复吸性能的影响

Effect of mineral content on moisture re-adsorption of dewatered lignite

利用XRF、低温灰化+XRD及FTIR分析胜利高灰褐煤中矿物质组成及特性,在30℃不同相对环境湿度条件下,考察了脱水褐煤的复吸性能,研究了矿物含量对脱水褐煤复吸性能的影响.结果表明:胜利褐煤中矿物有石英、高岭石、白云母、石膏、正长石和赤铁矿等,其中石英和高岭石含量最高,分别占矿物总量的38.1%和28.4%;脱水褐煤的复吸性能受到环境湿度和矿物含量的影响,同一相对湿度下煤样的复吸率随着矿物含量的升高而降低;煤中矿物表面基团吸附水分子的能力较有机含氧官能团弱.

The elemental composition and characteristics of Shengli lignite(SL)with high ash content were investigated using a X-ray fluorescence(XRF),a low temperature asher,X-ray diffraction(XRD)and Fourier transform infrared spectroscopy(FTIR).The influence of mineral content on moisture re-adsorption of dewatered SL was researched.The adsorption experiments under a constant temperature of 30 ℃ with different humidity were carried out to elucidate the relationship between mineral matter content and moisture re-adsorption valueφMRV of dewatered lignite.The results show that there are mainly six types of minerals existing in dewatered lignite,including quartz,kaolinite,muscovite,bassanite,orthoclase and hematite.Quartz and kaolinite are the predominant minerals with the contents of 38.1%and 28.4%,respectively.Both the relative humidity and content of minerals have impact on theφMRVof dewatered lignite.Under the same relative humidityφMRV decreases with the increasing of mineral content.Chemical groups on minerals surface have weaker ability to adsorb water molecules than organic oxygen-containing functional groups.