不同水煤浆分散剂与煤之间的相互作用规律研究Ⅹ分散剂在煤粒表面上的吸附作用特征

Interaction between different CWS dispersants and coal Ⅹ Adsorptive characteristics of dispersant on coal surface

研究了6种水煤浆分散剂在14种不同变质程度煤上的吸附作用特征。结果表明,多数分散剂在煤粒表面达到单层饱和吸附后,又形成多层吸附,单层饱和吸附量与煤的变质程度、比表面积以及分散剂的性质有关。在相同粒度分布下,煤的变质程度越低,表面含氧亲水官能团的比例越高,孔隙率越高,比表面积越大,这对增大吸附量有利。煤的变质程度越高,其表面疏水区面积的比例越高,分散剂通过疏水基团紧密吸附在煤表面的比例越大,这对增加高阶煤的吸附量有利。对不同煤,是变质程度还是比表面积为吸附分散剂的主控因素,主要依赖于分散剂的结构与性质。对同种煤,疏水与亲水基团呈线型分立分布的分散剂,吸附量明显高;而疏水与亲水基团呈线型间隔分布的分散剂,吸附量明显小。

The adsorption characteristics of 6 CWS dispersants on 14 coals surface were studied. The results show that most dispersants exhibit multi-layer adsorption after achieving monomolecular layer saturated adsorption. The saturated adsorption amount of mono-layer is mainly dependent on the coal rank, specific surface area of coal and the structure and property of dispersant. Under the same particle size distribution, either the higher the coal rank, the larger the adsorption amount of dispersant on coal surface; or the larger the specific surface of coal, the larger the adsorption amount. For different coals, the structure and property of dispersant will affect whether the coal rank or the specific surface of coal is the main factor to determine the adsorption of dispersant. The saturated adsorption amount for dispersant on unit surface area of coal increases with increasing coal rank and decreasing porosity of coal. When the dispersant is a length chain polymer, its hydrophilic and hydrophobic groups are linear schismatic distribution, resulting in a larger adsorption amount owing to the dispersant adsorbing on the coal particle surface by vertical form. When the hydrophilic and hydrophobic groups of dispersant are linear alternate distribution, leading to a smaller adsorption amount owing to the dispersant adsorbing on the coal particle surface bv horizontal form.