基于X射线衍射实验的堆垛结构对煤尘润湿性的影响

为了研究煤尘堆垛结构对其润湿性的影响,对从全国选取的10种不同变质程度煤样进行X射线衍射实验,结合液-固界面动态接触角测定结果,分析得到煤尘微晶参数与其润湿性之间的关系. 结果表明,无机矿物种类随着煤样变质程度的提高逐步减少,且原生矿物种类数量越多,润湿性则越好,次生矿物对煤尘润湿性的影响则较小. 变质程度高的煤种晶态成分较多,芳晶结构单元较大,芳香环缩合度较高;而中低变质程度煤种的非晶态成分较多,往往是一些亲水性的烷基小分子侧链、含氧官能团等. 随着堆砌度和延展度不断升高,面网间距逐渐减小,煤尘润湿性逐步变差. 当煤尘X射线衍射的堆砌度为18. 5 nm,延展度为41. 7 nm,面网间距为0. 898 nm时,煤尘润湿性最佳,其X射线衍射微晶参数越接近上述组合,润湿性越好.

Effect of stacking structure on the wettability of coal dust based on X-ray diffraction experiment

To investigate the effect of stacking structure on the wettability of coal dust, ten selected coal samples from China's dif-ferent regions with different metamorphic grades were analyzed by X-ray diffraction. In combination with the dynamic contact angle de-termination results of the liquid- solid interface, the relationship between microcrystalline parameters and the wettability of coal dust was deduced. The results show that the inorganic mineral types gradually decrease with increasing metamorphic grade, and the more the primary mineral types are, the better the wettability of coal dust is, but the secondary minerals have no significant influence on the wettability of coal dust. For different coal types, the higher the metamorphic grade of coal is, the more the crystalline component is, the bigger the structural unit of aromatic microcrystals is, and the higher the aromatic ring condensation degree will be. While the coals with low-medium metamorphic grades have more amorphous components, which include hydrophilic alkyl side chains of small mole-cules, oxygen-containing functional groups, etc. With increasing stack degree and spread degree, the plane spacing decreases gradual-ly, and the wettability of coal dust becomes worse. When the stack degree is 18. 5 nm, the spread degree is 41. 7 nm and the plane spacing is 0. 898 nm, the wettability of coal dust will be the best. The closer the X-ray diffraction microcrystalline parameters are to the above combinations, the better the wettability of coal dust is.