煤表面润湿性的影响因素

为了深入研究煤表面润湿性的影响机理,选用16种不同变质程度的煤样,利用JC2000C1接触角测量仪表征润湿性大小。通过煤尘的镜质组反射率测定、工业分析、元素分析、红外光谱实验、激光粒度仪测定,研究了煤的变质程度(煤阶),化学组成,含氧官能团,粒度分形维数,比表面积等性质,并用最小二乘法与接触角建立线性拟合。研究表明:煤表面润湿性主要取决于氧含量、水分、灰分和含量官能团;亲水性含氧官能团主要为910~940 cm-1羟基变形振动和3 400~3 450 cm-1芳香羟基伸缩,在所测煤样中羰基和羧基表现不明显;同时随着煤阶,碳含量,固定碳的增大,其接触角逐渐增大,润湿性变差;利用分形维数表征粒度分布,随着煤粒径D10,D50,D90变小,分形维数增大,接触角变大,润湿性变差。

Influence factors of coal surface wettability

In order to study the influence mechanism of coal surface wettability,16 kinds of coals with different metamorphic degrees were characterized by the measurement of contact angle.Metamorphic of coal (rank),chemical composition,oxygen containing functional groups,the fractal dimension of coal,and the specific surface area were studied by means of virtrinite reflectance determination,industry analysis,elemental analysis,infrared spectrum experiment,and the determination of laser granulometer.The least square method and the contact angle were used to establish the linear fitting.The results verify that coal surface wettability mainly depends on oxygen content,moisture,ash and the content of functional groups.The hydrophilic functional groups mainly include the 910-940 cm-1 hydroxyl deformation and the 3 400-3 450 cm-1 aromatic hydroxyl extension,carbonyl and carboxyl groups were not obvious in the samples.At the same time,along with the increase of coal rank,carbon content and fixed carbon,the contact angle increase and the wetting property becomes worse.Fractal dimension is used to characterize particle size distribution,with the coal particle size D10, D50,and D90 becoming smaller,the fractal dimension increases,the contact angle becomes larger,and the wetting property becomes worse.